阅读说明：本技术 台车 (Trolley ) 是由 山吉夫·塔克亚 卡尔·迈克尔·韦森 安迪·科佩 于 2017-01-30 设计创作，主要内容包括：一种用于在其上运输产品的台车,该台车包括：具有产品支撑表面和相反的下侧面的顶部、设置在下侧面上的多个脚轮,两个脚轮是旋转脚轮,旋转脚轮被构造成相对于产品支撑表面转动；偏压装置,所述偏压装置被构造成将每个旋转脚轮的轮子向第一平衡位置偏压。在下侧面上设置多个加强肋部；其中所述多个加强肋部中的至少一个加强肋部是弯曲的加强肋部；并且所述至少一个弯曲的加强肋部从第一脚轮安装区域延伸到第二脚轮安装区域。还包括,一种台车携载托盘,该台车携载托盘包括设置有台车接纳层的托盘,其中台车接纳层设置有用于接纳旋转脚轮的大致矩形的轮子接纳凹部,并且设置有用于接纳固定脚轮的大致矩形的轮子接纳凹部。(A trolley for transporting products thereon, the trolley comprising: a top having a product supporting surface and an opposite lower side, a plurality of casters disposed on the lower side, both casters being swivel casters configured to swivel relative to the product supporting surface; a biasing device configured to bias the wheel of each swivel caster towards a first equilibrium position. Providing a plurality of reinforcing ribs on the lower side; wherein at least one of the plurality of reinforcing ribs is a curved reinforcing rib; and the at least one curved reinforcing rib extends from the first caster mounting area to the second caster mounting area. Also included is a trolley carrying tray comprising a tray provided with a trolley receiving layer, wherein the trolley receiving layer is provided with a substantially rectangular wheel receiving recess for receiving swivel castors and is provided with a substantially rectangular wheel receiving recess for receiving rigid castors.)

1. A pallet for carrying a pallet, comprising a pallet provided with a pallet receiving layer, wherein

The trolley-receiving layer is provided with a substantially rectangular wheel-receiving recess for receiving the swivel caster wheel, and with a substantially rectangular wheel-receiving recess for receiving the rigid caster wheel.

2. The trolley carrying tray of claim 1,

the swivel caster wheel-receiving recess is longer than the fixed caster wheel-receiving recess.

3. The trolley carrying tray according to claim 1 or 2,

the swivel caster wheel-receiving recess is wider than the rigid caster wheel-receiving recess.

4. The trolley carrying tray of claim 3,

the swivel caster wheel-receiving recess is at least 5mm wider than the rigid caster wheel-receiving recess.

5. The trolley carrying tray according to claim 1 or 2,

the swivel caster wheel-receiving recess is located toward the center of the trolley carrying tray, and the fixed caster wheel-receiving recess is located at an end of the trolley carrying tray.

6. The trolley carrying tray according to claim 1 or 2,

the wheel-receiving recesses of the trolley-receiving floor are arranged to receive the casters of the four pallets.

7. The trolley carrying tray according to claim 1 or 2,

sixteen wheel-receiving recesses are provided in the trolley-receiving floor.

8. The trolley carrying tray according to claim 1 or 2,

at least some of the wheel-receiving recesses have chamfered ends.

9. The trolley carrying tray according to claim 1 or 2,

the wheel-receiving recess has a bottom surface formed by a trolley-receiving layer.

10. The trolley carrying tray of claim 9,

the bottom surface of the wheel-receiving recess is flat.

11. The trolley carrying tray according to claim 1 or 2,

the blocks disposed at the corners of the trolley carrying the pallet have a length of at least 250 mm.

12. A trolley for transporting products thereon, the trolley comprising:

a top having a product supporting surface and an opposite underside,

a plurality of reinforcing ribs provided on the lower side;

wherein at least one of the plurality of reinforcing ribs is a curved reinforcing rib; and is

The at least one curved reinforcing rib extends from the first caster mounting area to the second caster mounting area.

13. The trolley of claim 12 wherein,

the first caster wheel mounting area includes a first mounting point that receives a fixture for securing the first caster wheel, and the second caster wheel mounting area includes a second mounting point that receives a fixture for securing the second caster wheel.

14. The trolley of claim 13 wherein,

the first and second mounting points include first and second apertures.

15. The trolley of claim 13 wherein,

the securing means is a self-tapping threaded fastener.

16. The trolley of claim 13 wherein,

the at least one curved reinforcing rib extends between the first mounting point and the second mounting point.

17. The trolley of claim 16 wherein,

at least eight ribs extend from at least one of the mounting points of one of the caster mounting areas.

18. The trolley of any one of claims 12 to 17, further comprising a third caster mounting area and a fourth caster mounting area, and wherein each caster mounting area is connected to at least two other caster mounting areas by at least one curved rib.

19. The trolley of any one of claims 12 to 17,

the distance between one side of the trolley and the reinforcing rib portion immediately adjacent to the side of the trolley is smaller than the average distance between the plurality of reinforcing rib portions.

20. The dolly of any one of claims 12 to 17, further comprising four wheel receiving portions arranged in the product support surface, each wheel receiving portion configured to receive a wheel from another dolly, wherein the depth of the wheel receiving portion is greater than 15 mm.

21. The dolly of any one of claims 12 to 17, further comprising four wheel receiving portions arranged in the product support surface, each wheel receiving portion configured to receive a wheel from another dolly, wherein the depth of the wheel receiving portion is greater than 20 mm.

22. The trolley of claim 20 wherein,

the at least one wheel receiving portion is substantially aligned with the respective at least one caster wheel mounting area.

23. The trolley of claim 20 wherein,

there is an offset between at least one wheel receiving portion and a corresponding at least one caster wheel mounting area, the offset defining an offset area of the wheel receiving portion.

24. The trolley of claim 23 further comprising an additional reinforcing rib arranged to extend at least partially into the offset region of the wheel receiving portion.

25. The trolley of claim 24 wherein,

the additional reinforcing rib has a first end connected to the reinforcing rib and a second end not connected to the reinforcing rib.

26. The trolley of any one of claims 12 to 17,

the trolley is a quarter trolley.

27. The trolley of any one of claims 12 to 17,

at least one of the swivel casters includes a braking mechanism that is actuatable to prevent rotation of the wheel of the at least one swivel caster.

Technical Field

The present invention relates to a trolley and a trolley carrying tray for carrying a trolley.

Background

Trays for dispensing products from one location to another are well known and they can be provided in a variety of different sizes. Including but not limited to compliance with ISO 6780: the rectangular planar dimensions of a load-bearing platform (commonly referred to as a pallet) of the size 2003(E) have a length and width of 1200mm x 800mm (commonly referred to as european size), 1200mm x 1000mm (commonly referred to as full size), and 1219mm x 1016 mm. The term "half-tray" is half the size of a standard tray, depending on the particular standard used. Similarly, the term "quarter-pallet" is one-quarter of the size of a standard pallet, depending on the particular standard used. For example, if the standard used in one region is 1200mm x 800mm, then a half pallet would have dimensions of 800mm x 600mm and a quarter pallet would have dimensions of 600mm x 400 mm. These standard sizes are also applicable to wheeled platforms commonly referred to as dollies and also referred to as on-wheel pallets.

The present inventors have recognized that various improvements can be made to the trolleys currently in use. The present invention relates to such improvements.

Disclosure of Invention

According to a first aspect of the present invention, there is provided a trolley for transporting products thereon. The trolley includes a top portion having a product supporting surface and an opposite underside. The trolley further includes a plurality of casters disposed on the lower side, both casters being swivel casters configured to swivel relative to the product support surface; and a biasing device configured to bias the wheel of each swivel caster towards a first equilibrium position.

Advantageously, by providing a biasing device according to the first aspect, the wheels of the caster may be biased towards a preferred orientation, which may assist in stacking the trolleys. Furthermore, such biasing means may be used to prevent unwanted rotation of the wheels, which may lead to instability and damage to the trolley, wheels or hand operated equipment.

Alternatively, the biasing means may be provided by a spring. More than one spring, for example two or more springs, may be used. Alternatively, any elastic material may be used as the biasing means, such as an elastic cord.

Alternatively, the biasing device may be configured to provide a torque to the wheel when the wheel is oriented away from the first equilibrium position. This torque may then be used to bias the wheels back to the equilibrium position.

Optionally, the two casters have a fixed orientation relative to the product support surface. Such casters may be "fixed" casters, i.e. casters that cannot rotate.

Optionally, the trolley may further comprise an offset between the vertical axis of rotation of the swivel caster and the axis of rotation of the wheel of between 30mm and 50 mm. Such an offset may facilitate steering of the trolley.

Alternatively, the first equilibrium position may be such that the wheels are oriented along the length of the trolley. That is, the wheels are directed along the axis of the trolley when in the first equilibrium position. Optionally, the first equilibrium position is the only equilibrium position. That is, regardless of the orientation of the wheel, it will be biased in only one particular direction.

Optionally, the biasing means may be further arranged to bias the wheel towards the first equilibrium position when the wheel is in the first orientation, and the biasing means may be further arranged to bias the wheel towards the second equilibrium position when the wheel is in the second orientation.

Alternatively, the first equilibrium location and the second equilibrium location may be 180 degrees apart.

Alternatively, the first orientation may be an orientation in which the wheels are less than 90 degrees from the first equilibrium position.

Alternatively, the second orientation may be an orientation in which the wheels are less than 90 degrees from the second equilibrium position.

Optionally, the trolley may further comprise a plurality of reinforcing ribs provided on the lower side. The at least one reinforcing rib may be a curved reinforcing rib, and the at least one curved reinforcing rib may extend from the first caster mounting area to the second caster mounting area.

Optionally, the first caster mounting area may include a first mounting point that receives a fixture to secure the first caster, and the second caster mounting area may include a second mounting point that receives a fixture to secure the second caster.

Optionally, the first and second mounting points may comprise first and second apertures. For example, the aperture may be a hole in the underside of the trolley.

Alternatively, the securing means may be a self-tapping threaded fastener.

Optionally, at least one curved reinforcing rib may extend between the first mounting point and the second mounting point.

Optionally, at least eight ribs may extend from at least one mounting point of one mounting region.

Optionally, the trolley may further comprise a third mounting region and a fourth mounting region, and wherein each mounting region may be connected to at least two other mounting regions by at least one curved rib. That is, the curved ribs may extend between each mounting region to at least two other mounting regions.

Alternatively, the distance between a side of the trolley and the reinforcing rib immediately adjacent to the side of the trolley may be less than the average distance between the plurality of reinforcing ribs.

Optionally, the trolley may further comprise four wheel receiving portions arranged in the product supporting surface, each wheel receiving portion may be configured to receive a wheel from another trolley, wherein the depth of the wheel receiving portions may be greater than 15 mm. Alternatively, the depth of the wheel receiving portion may be greater than 20 mm.

Optionally, the at least one wheel receiving portion may be substantially aligned with the respective at least one mounting region. That is, the wheel receiving portions are aligned with their respective mounting areas when viewed in plan.

Optionally, there may be an offset between at least one wheel receiving portion and a corresponding at least one mounting region, the offset defining an offset region of the wheel receiving portion. The offset region may be a portion of the wheel-receiving portion that is not aligned with its corresponding mounting region. Such offset areas may suffer from reduced structural integrity because the mounting plate of the respective caster may not extend over the offset area.

Optionally, the trolley may further comprise additional reinforcing ribs, which may be arranged to extend at least partially into the offset region of the wheel receiving portion. Additional reinforcing ribs may provide further reinforcement in the offset region.

Optionally, the additional reinforcing rib has a first end and a second end, the first end may be connected to the reinforcing rib and the second end may be unconnected to the reinforcing rib. That is, the additional reinforcing rib may terminate before reaching the other rib.

Alternatively, the trolley may be a quarter trolley.

Optionally, the at least one swivel caster comprises a brake mechanism that is actuatable to prevent rotation of the wheel of the at least one swivel caster.

According to a second aspect of the present invention, there is provided a trolley for transporting products thereon. The trolley includes a top portion having a product supporting surface and an opposite underside. A plurality of reinforcing ribs are provided on the lower side. The at least one reinforcing rib is a curved reinforcing rib, and the at least one curved reinforcing rib extends from the first caster mounting area to the second caster mounting area.

Advantageously, providing at least one curved reinforcing rib extending from the first caster mounting area to the second caster mounting area provides increased rigidity of the trolley between these points.

The term "curved" refers to a rib that connects two points but not by the shortest path between the points. The curved portion may be continuous or may comprise a series of straight sections separated by a series of discontinuous angular changes. The discontinuous variation in angle may be less than 30 degrees. In another embodiment, the angle may be less than 20 degrees.

Optionally, the first caster mounting area may include a first mounting point that receives a fixture to secure the first caster, and the second caster mounting area may include a second mounting point that receives a fixture to secure the second caster.

Optionally, the first and second mounting points may comprise first and second apertures. For example, the aperture may be a hole in the underside of the trolley.

Alternatively, the securing means may be a self-tapping threaded fastener.

Optionally, at least one curved reinforcing rib may extend between the first mounting point and the second mounting point.

Optionally, at least eight ribs may extend from at least one mounting point of one caster mounting area.

Optionally, the trolley may further comprise a third caster wheel mounting area and a fourth caster wheel mounting area, and wherein each mounting area may be connected to at least two other caster wheel mounting areas by at least one curved rib.

Alternatively, the distance between a side of the trolley and the reinforcing rib immediately adjacent to the side of the trolley may be less than the average distance between the plurality of reinforcing ribs.

Optionally, the trolley may further comprise four wheel receiving portions arranged in the product supporting surface, each wheel receiving portion may be configured to receive a wheel from another trolley, wherein the depth of the wheel receiving portions may be greater than 15 mm. Optionally, the depth of the wheel receiving portion is greater than 20 mm.

Optionally, the at least one wheel receiving portion may be substantially aligned with the respective at least one caster wheel mounting area. That is, the wheel receiving portions are aligned with their respective caster wheel mounting areas when viewed in plan.

Optionally, there may be an offset between at least one wheel receiving portion and a corresponding at least one caster wheel mounting area, the offset defining an offset area of the wheel receiving portion. The offset region is a portion of the wheel receiving portion that is not aligned with its corresponding caster mounting region. Such offset areas may suffer from reduced structural integrity because the mounting plate of the respective caster may not extend over the offset area.

Optionally, the trolley may further comprise additional reinforcing ribs, which may be arranged to extend at least partially into the offset region of the wheel receiving portion. Additional reinforcing ribs may provide further reinforcement in the offset region.

Optionally, the additional reinforcing rib has a first end and a second end, the first end may be connected to the reinforcing rib and the second end may be unconnected to the reinforcing rib. That is, the additional reinforcing rib may terminate before reaching the other rib.

Optionally, two or more ribs may extend from the mounting point to a first quadrant, wherein the first quadrant has an origin at the mounting point and encompasses a center of the trolley. The fewer ribs may extend from the mounting point to a second quadrant, wherein the second quadrant has an origin at the mounting point and encompasses an exterior corner of the trolley.

In this manner, the angle between the ribs extending toward the center of the trolley is substantially less than the angle between the ribs extending away from the center of the trolley.

Optionally, the at least one curved rib extends between a caster mounting area at one end of the quarter-trolley and a caster mounting area at an opposite end of the quarter-trolley. This arrangement may increase the strength of the quarter-pallet. This arrangement may reduce undesirable torsional flexing of the quarter-trolley (i.e., rotational flexing relative to a line extending from one end of the quarter-trolley to the opposite end). At least one curved rib may extend between the mounting points of the caster mounting area. Two or more curved ribs may extend between the caster mounting areas at one end of the quarter-trolley and the caster mounting areas at the opposite end of the quarter-trolley.

Optionally, the trolley is a quarter trolley.

Optionally, the at least one swivel castor comprises a braking mechanism which is actuatable to prevent rotation of the wheel of the at least one swivel castor.

According to a third aspect of the present invention, there is provided a trolley for transporting products thereon. The trolley includes a top portion having a product supporting surface and an opposite underside; a plurality of casters disposed on the underside, and a plurality of wheel-receiving portions disposed on the product-supporting surface. The depth of the wheel receiving portion is greater than 15 mm.

According to a fourth aspect of the present invention, there is provided a trolley carrying tray comprising a tray provided with a trolley receiving layer, wherein the trolley receiving layer is provided with a substantially rectangular wheel receiving recess for receiving a swivel castor and is provided with a substantially rectangular wheel receiving recess for receiving a rigid castor.

Optionally, the swivel caster wheel-receiving recess is longer than the rigid caster wheel-receiving recess.

Optionally, the swivel caster wheel-receiving recess is wider than the rigid caster wheel-receiving recess.

Optionally, the swivel caster wheel-receiving recess is at least 5mm wider than the rigid caster wheel-receiving recess.

Optionally, the swivel caster wheel-receiving recess is located towards the center of the trolley carrying tray and the fixed caster wheel-receiving recess is located at an end of the trolley carrying tray.

Optionally, the wheel receiving recesses of the trolley receiving layer are arranged to receive the castors of four pallets.

Optionally, sixteen wheel-receiving recesses are provided in the trolley-receiving floor.

Optionally, at least some of the wheel-receiving recesses have chamfered ends.

Optionally, the wheel-receiving recess has a bottom surface formed by a trolley-receiving layer.

Optionally, the bottom surface of the wheel-receiving recess is flat.

Optionally, the blocks provided at the corners of the tray have a length of at least 250 mm.

According to a fifth aspect of the present invention there is provided a trolley carrying tray of the fourth aspect of the invention having a trolley according to any one of the first to third aspects of the invention located thereon.

According to a fifth aspect of the invention there is provided a trolley carrying tray and trolley combination wherein

The trolley comprising a top portion having a product supporting surface and an opposite underside, a plurality of castors being provided on the underside, both castors being swivel castors configured to swivel relative to the product supporting surface, the trolley further comprising biasing means configured to bias the wheel of each swivel castor towards a first equilibrium position; and wherein

The trolley is located on a trolley carrying tray having a trolley receiving floor provided with a substantially rectangular recess which receives the trolley's caster.

Optionally, the two casters of the trolley have a fixed orientation relative to the product support surface and the recess receiving the swivel caster is wider than the recess receiving the fixed caster.

Optionally, the two casters of the trolley have a fixed orientation relative to the product support surface, and the recess receiving the swivel caster is longer than the recess receiving the fixed caster.

Optionally, the recess receiving the swivel caster wheel is located towards the center of the trolley carrying tray and the recess receiving the rigid caster wheel is located at an end of the trolley carrying tray such that the swivel caster wheel is located towards the center of the trolley carrying tray.

Optionally, there is a close fit between the rigid castors and the recesses receiving the rigid castors, thereby preventing large movements of the rigid castors along these recesses.

Optionally, the trolley carrying tray is provided with sixteen substantially rectangular recesses, each recess receiving a castor of the trolley, such that four trolleys are received by the trolley carrying tray.

Optionally, the swivel caster of the trolley is located towards the centre of the trolley carrying tray and the rigid caster of the trolley is located at the end of the trolley carrying tray.

Optionally, one swivel castor of each trolley is provided with a brake and the brakes are offset relative to each other in the width direction across which the trolley carries the trays.

Different aspects of the invention may be combined. Optional features of a given aspect of the invention may be combined with different aspects of the invention.

Drawings

FIG. 1 shows a perspective view of a quarter-wheel truck according to one embodiment of the present invention;

FIG. 2 shows a view of a first side of the quarter trolley of FIG. 1;

FIG. 3 shows a view of a second side of the quarter-wheel truck of FIG. 1;

FIG. 4 shows a view of the rear end of the quarter-wheel truck of FIG. 1, showing the end with two rigid castors;

FIG. 5 shows a view of the front end of the quarter-wheel truck of FIG. 1, showing the end with two swivel castors;

FIG. 6 shows a plan view of the quarter trolley of FIG. 1;

FIG. 7 shows a view from below of the quarter trolley of FIG. 1;

FIG. 8 shows a view from below of the quarter-wheel truck of FIG. 1 without casters;

figure 9 shows a view from below of the quarter trolley with the swivel castors in the outboard position;

FIG. 10 shows an underside view of the quarter trolley of FIG. 9 with the swivel castors in an inboard configuration;

FIG. 11 shows a view of the underside of the quarter trolley of FIG. 9 with the swivel caster turned 90 degrees clockwise from the inboard position;

FIG. 12 shows a view from below of the quarter trolley of FIG. 9 with the swivel caster rotated 90 degrees counterclockwise from the inboard position;

FIG. 13 shows a perspective view of the underside of the quarter-wheel truck;

figure 14 shows a cross-sectional side view of the wheel receiving portion;

FIG. 15 shows a cross-sectional side view of two trolleys in a stacked configuration;

FIG. 16 shows a side view of two trolleys in the stacked configuration of FIG. 15;

FIG. 17 shows a comparison of a stack of dollies according to one embodiment of the present invention with a stack of dollies of the prior art;

FIG. 18 shows a schematic cross section through a self-centering mechanism in a rest position according to an embodiment;

FIG. 19 shows a schematic cross-section through a self-centering mechanism in a rest position according to another embodiment;

FIG. 20 shows a cross-section through the self-centering mechanism of FIG. 19 in an unbalanced position;

FIG. 21 shows an enlarged perspective view of a corner of the quarter-wheel truck;

FIG. 22 shows an enlarged view of a slot that may form part of an embodiment of the present invention;

FIG. 23 shows an enlarged view of an attachment feature that may form part of an embodiment of the present invention;

fig. 24 and 25 depict a trolley carrying tray in accordance with an embodiment of the present invention;

fig. 26 and 27 depict trolley receiving levels with trolleys carrying pallets; and

fig. 28 to 30 show a trolley carrying tray having a trolley positioned thereon.

Detailed Description

Fig. 1 shows a perspective view of a quarter-trolley 1 according to one embodiment of the invention, and fig. 2 to 13 show the quarter-trolley 1 from a plurality of different viewpoints. The term "quarter-dolly" is considered to mean any dolly that is one quarter the size of a standard size pallet according to any particular standard or area. For example, compliance with ISO 6780: the rectangular planar dimensions of the platform or tray of 2003(E) have a length and width of 1200mm x 800mm (commonly referred to as european dimensions), 1200mm x 1000mm (commonly referred to as full dimensions) and 1219mm x 1016 mm. Although the following description refers to a quarter dolly, it should be understood that the invention can be applied to dollies of any size.

The quarter trolley 1 comprises a deck 2, the deck 2 may be formed from a plastics material such as polypropylene. The deck 2 comprises a product support surface 3, two sides 4a, 4b (where sides refer to sides along the length of the quarter trolley 1), two ends 4c, 4d (where ends refer to sides along the width of the quarter trolley 1) and an underside 5 (see fig. 7 and 8). The cart 1 has first and second caster 6a, 6b and first and second caster 7a, 7 b. For the following description, the end 4d of the quarter-trolley 1 containing the swivel castors 7a, 7b will be referred to as the front end, and the end 4c of the quarter-trolley 1 containing the fixed castors 6a, 6b will be referred to as the rear end.

According to one embodiment the quarter trolley 1 has a width of 399mm (+1mm, -2mm), a length of 599mm (+1mm, -3mm), a deck thickness of 40mm, a gap height (height of the quarter trolley 1 minus the deck 2) of 125mm and a total height of 165 mm. The length and width are chosen so that they do not exceed the standard dimensions when maximum tolerances are taken into account. Corresponding embodiments may be used for other sizes of dollies. In one embodiment, the rated load of the quarter-trolley 1 is 250 Kg.

The casters 6a, 6b, 7a, 7b are connected to the underside of the trolley 1 at four caster mounting areas 8, 9, 10, 11 (see fig. 8). Each caster mounting area 8, 9, 10, 11 comprises four mounting points in the form of apertures in the underside 5 of the deck 2 through which self-tapping threaded fasteners 14 can pass to allow the caster to be mounted to the quarter-trolley 1. The first fixed caster 6a is connected to the first caster mounting area 8 at mounting points 8a, 8b, 8c, 8 d. The second fixed castor 6b is connected to the second castor mounting area 9 at mounting points 9a, 9b, 9c, 9 d. The first swivel castor 7a is connected to the third castor mounting area 10 at mounting points 10a, 10b, 10c, 10 d. The second swivel caster 7b is connected to the fourth caster mounting area 11 at mounting points 11a, 11b, 11c, 11 d.

Although self-tapping threaded fasteners have been described as an example of how the casters 6a, 6b, 7a, 7b attach to the deck 2, it should be understood that any suitable fastening means may be used.

Each caster 6a, 6b, 7a, 7b comprises a mounting plate 12a, 12b, 13a, 13b (see fig. 7), two fork-shaped sections 15a, 15b, 16a, 16b and a wheel 17a, 17b, 18a, 18 b. The wheels 17a, 17b, 18a, 18b are mounted between their respective fork sections 15a, 15b, 16a, 16b by means of nuts and bolts 19, wherein the bolts 19 also provide wheel axles about which the wheels 17a, 17b, 18a, 18b rotate. It will be appreciated that other means, such as rivets, may be used to connect the wheels to the forks. The mounting plates 12a, 12b, 13a, 13b have four holes for receiving four self-tapping threaded fasteners 14 to allow mounting of the mounting plates on the caster mounting area on the underside 5 of the trolley 1.

In one embodiment, the wheels 17a, 17b, 18a, 18b have a diameter between 80mm and 120 mm. In a preferred embodiment, the wheels 17a, 17b, 18a, 18b have a diameter of about 100 mm. However, other wheel sizes may be used. The wheels 17a, 17b, 18a, 18b may be color coded to aid identification. In other words, the wheels 18a, 18b of the swivel castors 7a, 7b may have a different colour than the wheels 17a, 17b of the rigid castors 6a, 6 b. For example, the wheels 18a, 18b of swivel castors 7a, 7b may be blue and the wheels 17a, 17b of rigid castors 6a, 6b may be grey.

The swivel castors 7a, 7b are rotatable about axes perpendicular to the axis of rotation of the wheels 18a, 18 b. The rigid castors 6a, 6b do not have a mechanism that allows a swivel action and therefore cannot swivel about an axis perpendicular to the axis of rotation of the wheels 17a, 17 b. There is an offset OA (see fig. 2) between the wheel swivel axis 19 of the swivel caster 7a, 7b and the vertical swivel axis SA of the swivel caster 7a, 7 b. In one embodiment, the offset OA may be equal to a value between 30mm and 50 mm. In a preferred embodiment, the offset is about 40 mm.

One of the swivel castors 7b includes a brake mechanism 20, the brake mechanism 20 being actuatable to prevent rotation of the wheel 18 b. It should be understood that such a braking mechanism may be applied to any number of casters.

The castors 6a, 6b, 7a, 7b allow the quarter-trolley 1 to be easily moved over a surface such as a store or warehouse floor, with the swivel castors 7a, 7b allowing the quarter-trolley 1 to be steered as it is rolled. Fig. 9 to 12 show the swivel castors 7a, 7b in different orientations. Fig. 9 shows the swivel castors 7a, 7b oriented in the outboard direction. Fig. 10 shows the swivel casters 7a, 7b at 180 degrees to the outside direction (also referred to as the inside direction). Fig. 11 shows the swivel casters 7a, 7b at 90 degrees clockwise from the inside direction. Fig. 12 shows the swivel casters 7a, 7b at 90 degrees counterclockwise from the inside direction.

When the quarter trolley 1 is not in use, it can be stored together with other quarter trolleys by stacking the quarter trolleys on top of each other. The stack of quarter-trolleys 1 can be placed above a transport tray (commonly known as slave tray). To facilitate stacking of the quarter-trolleys 1, the product supporting surface 3 comprises four wheel receiving portions 21a, 21b, 22a, 22b, which take the form of recesses in the product supporting surface 3. Figure 14 illustrates a cross-section through a wheel receiving portion 22b according to one embodiment. The wheel receiving portions 21a, 21b, 22a, 22b are generally oval in shape and have a flat bottom surface 23. The length L of the flat bottom surface 23 is between 3mm and 7mm, preferably about 5 mm. The depth D of the wheel receiving portion (the distance from the flat bottom surface 23 to the product support surface 3) is between 20mm and 23mm, for example 21.7 mm. The width of the wheel receiving portion is between 35mm and 45mm and may be about 40 mm. The radius of the wheel receiving portion is between 45mm and 55mm and may be, for example, about 48 mm. In one embodiment, the radius of the wheel receiving portion is greater than the radius of the wheels 17a, 17b, 18a, 18 b. The shape of the wheel receiving portions 21a, 21b, 22a, 22b may be selected to more conveniently locate the wheels in the wheel receiving portions with minimal movement. For example, the wheel receiving portion may have a curved edge 24, the curved edge 24 being curved in a direction opposite to the curvature of the wheel receiving portion. These curved edges 24 help to more easily locate the wheel of another trolley in the wheel receiving portion. In an alternative embodiment, the radius of the wheel receiving portions 21a, 21b, 22a, 22b is smaller than the radius of the wheels 17a, 17b, 18a, 18 b. By having the wheel receiving portion with a smaller radius than the radius of the wheel, the wheel contacts the edge 24 of the wheel receiving portion and the wheel is effectively gripped by the edge 24. This arrangement can prevent unwanted movement of a dolly stacked on another dolly, for example, prevent the stacked dolly from rocking. In another embodiment, the radius of the wheel receiving portion is the same as the radius of the wheel.

In another embodiment, the wheel-receiving portion does not have a flat bottom surface, but rather includes a continuous oval curvature.

The stacking configuration of the quarter-trolleys 1 has been optimised to increase the number of trolleys stacked in a given height. The height of the single quarter trolley 1 is the distance from the bottom of the wheels to the surface of the product support surface 3, excluding the lip or other raised feature extending above the product support surface. Furthermore, the trolley clearance, i.e. the distance from the bottom of the wheels to the bottom of the deck 2, is not changed to allow the same Manual Handling Equipment (MHE) clearance as the quarter trolley of the prior art.

Fig. 15 and 16 show the second quarter trolley 1a stacked above the quarter trolley 1, showing the wheels of the second quarter trolley 1a in the wheel receiving portions of the quarter trolley 1.

Fig. 17 shows a plurality of quarter trolleys in a stacked arrangement. The stack 25 on the left shows sixteen quarter trolleys 1 according to an embodiment of the invention, and having a total height of 2310 mm. The bottom quarter trolley in the stack 25 has an effective height of 165mm and each additional quarter trolley has an effective height of 143mm, i.e. the wheel receiving portions allow the top quarter trolley to penetrate a distance of 22mm into the lower quarter trolley. In contrast, the right side stack 26 shows fifteen prior art quarter trolleys having a total height of 2315 mm. The bottom prior art quarter-trolley in the right-hand stack 26 has an effective height of 173mm, and each additional quarter-trolley has an effective height of 153 mm.

Thus, there is a reduced storage space requirement for storage of the quarter-trolleys and during transport of the quarter-trolleys (e.g. when the trolleys are collected, stored or transported). For example, a truck that was previously capable of transporting a stack of fifteen trolleys may now transport a stack of sixteen trolleys. This reduced stack height may also allow for safer handling by the user. In particular, when unloading a given number of quarter-trolleys, the user does not need to reach such a high height. By increasing the depth of the wheel receiving portion relative to existing quarter-trolleys, an increase in the number of quarter-trolleys that can be stacked within a given height has been achieved. Whereas the prior art quarter-trolley has a depth of 12mm of wheel receiving section, the embodiment of the quarter-trolley 1 of the invention has a depth of 21.7mm of wheel receiving section. This allows the wheels of the upper trolley to penetrate further into the wheel receiving portions of the lower trolley, thereby providing the upper trolley with an effective height that is lower than previously achievable. Generally, increasing the depth of the wheel receiving portion will reduce the stacking height of a given number of dollies. The depth may be, for example, greater than 15mm, and may be, for example, 20mm or greater.

Increasing the depth of the wheel receiving portion may result in a reduction in the structural integrity of the quarter-bogie 1. For example, a deeper wheel receiving portion means less space below the wheel receiving portion to accommodate the reinforcing ribs. Therefore, if a flat underside is to be maintained, the height of any reinforcing ribs below the wheel receiving portion must be reduced. Various aspects of the present invention are configured to counteract this reduction in structural integrity, and this is described in further detail below.

The deck 2 has a plurality of apertures 27 in the product support surface 3, the apertures 27 allowing liquid (e.g. water/rain) to pass through the quarter trolley 1. The deck 2 also has a plurality of raised points 28 (see fig. 2), the points 28 may help provide greater friction between the product support surface 3 and products placed on the product support surface 3. The quarter trolley 1 has three lashing locations 29 along each side 4a, 4b and one along each end 4c, 4 d. However, it should be understood that any number of banding locations may be used, such as three banding locations along the sides and ends. The deck 2 comprises two handle holes 30 for carrying the quarter trolley 1. The handle holes 30 are arranged adjacent the edges of the sides 4a, 4b of the trolley 1, in the middle between the corners of the trolley 1. This arrangement facilitates carrying the quarter trolley 1, allowing a user to hold the quarter trolley 1 vertically while carrying the quarter trolley 1. Further, by being arranged midway between the corners, the handle hole 30 coincides with the center of gravity of the cart 1 while the cart 1 is carried.

The underside 5 of the quarter trolley 1 is flat, seen from the side, for fork-lift trucks, conveyors and other MHEs to pick up and move the quarter trolley 1 more easily. For example, any features protruding from the underside (other than the castors) may be damaged when picked up by the forks of a forklift.

The quarter-trolley 1 has a plurality of horizontally arranged ribs 31 (see fig. 21) at its corners, the ribs 31 helping to apply and hold shrink wrap-which is commonly used to secure products to the quarter-trolley 1-on the products on the quarter-trolley 1. This is usually an alternative to banding, but both can be applied if desired. For example, the ribs 31 allow the stretch wrap to be more easily gripped by the quarter trolley 1 when the stretch wrap is wrapped around the product on the quarter trolley 1.

The quarter trolley 1 has four T-shaped edge recesses 32, wherein one T-shaped edge recess 32 is arranged on each side 4a, 4b and end 4c, 4d of the quarter trolley 1. The T-shaped edge recesses 32 are arranged to receive T-shaped tabs which can be selectively lowered from the base of a product tray or package which is loaded onto the quarter trolley 1. Such tabs allow the product tray or package to be locked onto the quarter-trolley or at least held more securely, thereby increasing stability.

The quarter-trolley 1 comprises four slots 33 (see fig. 22, which shows an enlarged view of the slots 32) in the product support surface 3 at the centre of each side 4a, 4b and end 4c, 4d of the quarter-trolley 1. When viewed in plan, the recessed slot 33 has a set of surrounding walls 4, a flat top 35 and a raised bottom 36. It also has a projection associated with it that interacts with the tab once it is inserted into the slot. The recessed slot 33 has a recessed protrusion 37 in the form of a rounded or part spherical member. The concave protrusions 37 are arranged with a rounded surface pointing substantially upwards and having a flat bottom facing downwards.

The recessed slot 33 includes a further member 38, the further member 38 being formed in a wall of the slot 33 opposite the projection 37. In the illustrated embodiment, the other member 38 is a tapered or angled leg. The other member 38 is shown as having a free end 39 which free end 39 extends to a plane vertically aligned with the nose of the projection 37, but which plane is at a level below the nose. In use, a tab on the underside of a bin placed on the quarter-trolley 1 can be caused to protrude into the slot 33 so that it will flex around the projection 37 and abut the other member 38, thereby remaining in place therein.

If the tab has a suitably positioned hole, the hole can engage and lock onto the projection 37 or another member 38.

In use, the tabs of the display are inserted into the slots 33. The tab is configured so that it has an aperture that can be fitted over the projection 37 to "snap" the tab into place. The diameter of the aperture in the tab may be the same or, when an elastic material is used for the tab or extension 37, slightly smaller than the diameter of the protrusion 37 to facilitate a tight fit.

The top of the recessed projection 37 is shown generally aligned with the recessed ledge 40 of the slot. The shelf portion 40 has a thickness portion therebelow which is integral with the further member 38 and which is arranged such that the further member extends perpendicular to the front edge 41 of the shelf portion-towards the recessed protrusion 37 and downwardly relative to the recessed protrusion 37. As shown, the front edge is curved to define the curved shape of the slot to snap the tab into place.

The slots 33 of the illustrated embodiment are recessed relative to the product support surface 3, but may be flush with the product support surface in other embodiments. Similarly, although the protrusions 37 are shown recessed relative to the product support surface, in other embodiments, the protrusions may be flush with the product support surface 3.

Although a particular shape of slot 33 is shown, any other shape of slot may be used. For example, the slots may be curved or non-rectangular. Similarly, although a particular shape of protrusion 37 is shown, the protrusion may have any shape suitable for receipt in the aperture of the tab.

Fig. 23 is a view of one side of the attachment feature 80. The attachment features are provided on the ends 4c, 4d of the quarter trolley. Two attachment features 80 can be seen in fig. 1. Fewer or more attachment features 80 may be provided. These features include a vertically disposed inwardly recessed slot 82. Each slot 82 has an open top for receiving a descending tab from the display package for positioning on the trolley. The slot 82 also has a set of engagement teeth 84 or members that extend transversely across the shorter width of the slot, i.e., members that extend perpendicular to the respective walls of the top of the trolley. These teeth are shown as having tapered sides (the faces of the side walls facing away from the top) and a flat bottom (the faces facing downward during normal use of the trolley), so they resemble teeth in a vertical plane when viewed parallel to the longitudinal length of the slot. In this example, the set of teeth includes three teeth. However, fewer or more teeth may be provided. Even a single tooth may be provided.

Sidewalls 86 extend inwardly from the outer edges of the slot 80 and define a gap 88, which gap 88 can receive the edge of a tab (which gap is visible in fig. 1). The gap allows for lateral and longitudinal positioning and clamping or retention of the tab in the slot. The teeth, members, elements, points or projections then also hold the tabs vertically, providing a secure fixation of the tabs once inserted into the slots, but the tabs can be easily removed by, for example, lateral ejection if desired.

Instead of serrations, other shapes may be provided, including circular members. A flat bottom is also not necessary (for both forms of slot), but particularly where the tab has a recess for receiving the tooth, member, element, point or projection, the flat bottom (or lowermost outward point) does help provide a form-fitting location for gripping the tab. If such holes are provided, the teeth, members, elements, points or projections may grip the lowered tabs or engage in the holes therein to more securely locate the package on the trolley.

As mentioned above, in this example there is a pair of such slots at each end of the top of the trolley. Further, it can be observed that each of these individual slots is paired with a matching one of the slots at the opposite end of the trolley.

The slots may be recessed by about 4mm relative to the end walls of the trolley to accommodate tabs made of sheet material up to 4mm in thickness (e.g. corrugated cardboard) without crushing the corrugated members in those edge portions. Thicker plates can also be accommodated, but they are squeezed if necessary. For some applications a wider width may be preferred, but for most applications 4mm is preferred.

The quarter trolley has two one-eighth display slots 42, the display slots 42 being arranged to cooperate with opposing slots 43 for locating and retaining one-eighth size display. Since the quarter-trolley 1 is one quarter of the size of a standard platform, such an eighth-sized display is dimensioned such that two of them can be mounted to the quarter-trolley. The one-eighth size display thus occupies about half of the product support surface 3 of the quarter-dolly 1.

In one embodiment, the two swivel castors 7a, 7b include a self-centering mechanism (see fig. 18-20) that provides a torque to allow the wheels 18a, 18b of the swivel castors 7a, 7b to return to a predetermined position. The torque provided to the wheels 18a, 18b is set to be low enough so that the wheels 18a, 18b do not self-center when the unloaded quarter-bogie 1 is on the ground, but strong enough to return the wheels 18a, 18b to a predetermined position when the wheels 18a, 18b are free to rotate, such as when the wheels 18a, 18b are not in contact with the ground. In one embodiment, the weight of the unloaded quarter trolley 1 is between 5Kg and 7 Kg. Thus, the torque provided by the self-centering mechanism is configured such that when the quarter-trolley 1, weighing between 5Kg and 7Kg, is placed on a typical floor (for example concrete or tile), the torque is not sufficient to overcome the friction between the floor and the caster.

In one embodiment, the self-centering mechanism biases the wheels 18a, 18b of the swivel castors 7a, 7b to an outboard position, as shown in fig. 7. This arrangement means that during stacking, when the quarter trolley 1 is lifted from the ground to be placed over a transport pallet or another quarter trolley 1, the wheels 18a, 18b will automatically be correctly oriented so as to be received in their respective wheel receiving portions 21a, 21 b. In prior art quarter-trolleys, the wheels must be manually turned from any number of possible orientations during lifting and transport so that the wheels are received in the wheel receiving portions. This operation must be done for each lifted trolley and this can consume considerable time and pose health and safety risks.

Fig. 18 shows a cross section through the swivel caster 44 in a plane perpendicular to the swivel axis SA. The axis of rotation SA is marked with a cross and has two circumferential arrows around the cross, which arrows point in a counter-clockwise direction. This is for illustrative purposes only and it should be understood that the wheels may rotate in both clockwise and counterclockwise directions. Swivel caster 44 includes a self-centering mechanism according to one embodiment. Note that although the embodiment of the quarter-trolley 1 shown in fig. 1 to 17 and 21 to 22 does not show a self-centering mechanism, the self-centering mechanism may be used with any embodiment of the quarter-trolley 1. Fig. 18 shows the self-centering mechanism in a rest position. The self-centering mechanism comprises two springs 45, 46, the two springs 45, 46 providing a biasing force for the self-centering mechanism. Each spring is connected at one end 45a, 46a to a roller bearing 47 and at their other end 45b, 46b to a mounting point 48, 49 on each fork 50, 51 of the caster 44. The roller bearing 47 is mounted on the plate 52 at a position offset from the axis of rotation SA. The plate 52 is fixed relative to the mounting plate 53 of the caster 44 so that the plate 52 does not rotate relative to the mounting plate 53. That is, when the wheel 54 of the caster 44 rotates about the rotation axis SA, the plate 52 and the roller bearing 47 do not rotate about the rotation axis SA. Note that the roller bearing 47 may rotate about its own axis to prevent the springs from physically contacting each other as the wheel 54 rotates. The springs 45, 46 are examples of biasing means.

When in the rest position, as shown in fig. 18, each spring 45, 46 provides an equal and opposite force component in a direction perpendicular to the direction of the wheels 54. That is, the forces provided by the springs 45, 46 are balanced (i.e., cancelled out), and thus, the wheel 54 remains in a balanced position without any other force. As the wheel 54 rotates about the axis of rotation SA, the forces provided by the springs 45, 46 become unbalanced as one of the springs stretches more than the other. This provides a net component of force that is used to rotate the wheel 54 back to the equilibrium position. Thus, the self-centering mechanism serves to bias the wheel 54 to the rest position when the wheel is in any other position.

In an alternative embodiment, the springs 45, 46 may be attached to the caster 44 or a portion of the trolley that is configured to not rotate about the axis of rotation SA with rotation of the wheel, and the plate 52 may be configured to rotate about the axis of rotation SA with rotation of the wheel.

In the prior art quarter-trolley, the swivel caster wheels are located sufficiently on the inside of the quarter-trolley so that the orientation of the wheels does not cause the wheels to protrude beyond a portion of the sides of the quarter-trolley, i.e., the entire wheel is contained within the perimeter of the prior art quarter-trolley. This helps prevent the quarter-trolleys from falling off the stack of trolleys during stacking. If a portion of the wheel protrudes beyond the side of a quarter-trolley and it is placed on top of another quarter-trolley, a misaligned wheel may cause instability, which may cause the quarter-trolley to fall off the stack. However, this results in narrower tracks (i.e. shorter distance between the castors), which may lead to stability problems when using the castors, for example when loading or moving around a warehouse. Conversely, by using swivel castors with a self-centering mechanism, the castors can be placed closer to the side of the trolley, since it is well known that when the trolley is lifted, the wheels will not protrude to the side of the trolley.

In another embodiment, the self-centering mechanism biases the wheel of the swivel caster into one of two positions depending on how the wheel is oriented when the wheel is lifted from the ground surface. For example, the self-centering mechanism may bias the wheel to return to the inboard position when the wheel is oriented at any position less than 90 degrees from the inboard position, and may bias the wheel to return to the outboard position when the wheel is oriented at any position less than 90 degrees from the outboard position. Such an embodiment of a self-centering mechanism is shown in fig. 19 and 20.

Fig. 19 shows a cross section through the swivel caster 55 in a plane perpendicular to the swivel axis SA. The self-centering mechanism includes two opposing compression springs 56, 57, the two opposing compression springs 56, 57 being coupled to a housing 58, the housing 58 being fixed relative to a mounting plate (not shown) of the caster 55, i.e., the housing 58 does not rotate relative to the trolley when the wheels (not shown) of the swivel caster 55 are rotated. Each spring 56, 57 is connected at one end to a housing 58 and at the other end to cam surfaces 59, 60 facing each other. The cam surfaces 59, 60 are configured to act on two roller bearings 61, 62. The two roller bearings 61, 62 are located on each side of the axis of rotation SA and are rotatably fixed relative to the wheel such that they rotate about the axis of rotation SA as the wheel rotates, i.e. if the wheel rotates 90 degrees, the roller bearings 61, 62 rotate 90 degrees about the axis of rotation SA. Although not shown, the roller bearings 61, 62 may be rotatably connected to the wheel by a suitable frame or plate, for example using screws. The springs 56, 57 are examples of biasing means.

Fig. 19 shows the self-centering mechanism in a rest position, in which the compression springs 56, 57 are in their relaxed state and neither roller bearing 61, 62 is in contact with the cam surfaces 59, 60. There is a small distance between the two sides of the roller bearings 61, 62 and the cam surfaces 59, 60, which results in a small amount of play in the rotation of the wheel. In an alternative embodiment, the compression springs 56, 57 may be arranged such that they are slightly compressed when in the equilibrium position, i.e. the roller bearings 61, 62 contact the cam surfaces 59, 60 when in the equilibrium position and there is no play when the wheel rotates. When in the equilibrium position, there is no net force acting on the roller bearings 61, 62 and no net torque acting on the wheel. Without any other force, the wheels remain in the equilibrium position.

Fig. 20 shows the self-centering mechanism when the wheel is turned about the axis of rotation SA. When the wheel rotates counterclockwise about the rotation axis SA, the roller bearings 61, 62 also rotate counterclockwise about the rotation axis SA. This causes the roller bearings 61, 62 to contact and act on the opposing cam surfaces 59, 60. Since the springs 56, 57 do not rotate as the wheel rotates, this action causes the springs 56, 57 to be compressed as the roller bearings 61, 62 rotate about the axis of rotation SA. Each compression spring 56, 57 acts on the opposite roller bearing 61, 62, which introduces a net torque into the system, i.e. the wheel will rotate back to the equilibrium position without any other forces.

The characteristics of the self-centering mechanism (e.g. spring strength and relative dimensions of the components) are chosen such that the torque provided to the wheels is weak enough that it cannot overcome the friction between the wheels and the ground on which the unloaded quarter-trolley 1 rests, but strong enough that when the quarter-trolley 1 is lifted from the ground, the wheels turn back to the equilibrium position.

The self-centering mechanism of the embodiment of fig. 19 and 20 has two equilibrium positions 180 degrees apart. When the wheel is rotated more than 90 degrees from the equilibrium position shown in figure 19, the springs 56, 57 and roller bearings 61, 62 will return the wheel to a second equilibrium position 180 degrees from the first equilibrium position.

Knowing that the wheels are in one or both positions improves the efficiency of stacking the quarter-trolleys 1 when the quarter-trolleys 1 are lifted off the ground, since the wheels will already be in the correct position to be received in the respective wheel receiving portion or will need to be turned 180 degrees to align with the wheel receiving portion. Furthermore, the self-centering mechanism may also prevent uncontrolled rotation of the wheels during any MHE movement, for example when quarter car 1 is lifted from the ground. By preventing such uncontrolled rotation, the likelihood of the caster being damaged or inadvertently damaging the MHE is reduced. Furthermore, if the wheels are free to rotate and they hit the MHE during maneuvering, the load of the impact may be transferred to the product carried on the trolley, which may cause the product to tip over and be damaged. Thus, preventing such uncontrolled rotation may also protect the product carried by the trolley. Additionally, knowing the orientation of the wheels can reduce the chance of inadvertently damaging the wheels or casters with the MHE, i.e., the wheels of the casters are less likely to be "side" hit.

The deck 2 comprises a plurality of reinforcing ribs 63 on the underside 5 of the product support surface 3, the reinforcing ribs 63 being configured to resist deformation when loaded (see figure 8). Aspects of the invention relating to ribs may be particularly advantageous on the quarter-bogie 1 of the invention for a number of reasons. For example, the increased rigidity provided by the ribs 63 helps to counteract the reduction in structural integrity of the quarter-wheel truck 1 due to the deeper wheel receiving sections (see above). Furthermore, when a large load is applied, any deflection in the deck 2 of the quarter-trolley 1 may cause the wheels of the quarter-trolley 1 to move apart. This may make the quarter-trolley unstable when loaded, which may present health and safety risks. The ribs 63 serve to reduce this deflection.

The reinforcing ribs 63 extend from the underside 5 of the product support surface 3. At least some of the ribs 63 have the same height as the thickness of the deck. That is, the rib 63 is arranged not to protrude below the side faces 4a, 4b of the quarter trolley 1. However, it should be understood that the ribs 63 may have a different height than the sides 4a, 4b and ends 4a, 4 b. The ribs 63 define cavities 63a between the ribs 63 and/or the sides 4a, 4b and the ends 4c, 4d of the trolley 1.

The ribs 63 may have an average thickness of about 3 mm. The ends of the ribs 63 may be tapered to facilitate removal of the ribs 63 from the mold during the manufacturing process. The thickness of the ribs may vary between about 3.3mm to about 2.7mm along the height or a portion of the height of the ribs 63. The angle of taper from the vertical may be between 0.4 degrees and 2 degrees on one or both sides of the rib 63, and preferably may be about 1.25 degrees on one or both sides of the rib 63.

Some of the reinforcing ribs are curved ribs 64. The term "curved" refers to a rib that connects two points but not by the shortest path between the points. The curved portion may be continuous or may comprise a series of straight sections separated by a series of discontinuous angular changes. The discontinuous variation in angle may be less than 30 degrees. In another embodiment, the discrete variations of the angle may each be less than 20 degrees.

The curved ribs 64 provide increased rigidity to the quarter-bogie 1 while using less material than conventional straight ribs. That is, a single curved rib may replace a plurality of straight ribs while providing sufficient protection against deformation caused by side impacts and loading of the quarter-bogie 1. Furthermore, the quarter trolley 1 is lighter than prior art quarter trolleys, since less material is used in the construction of the quarter trolley 1. Some of the apertures 27 for drainage and weight reduction are also arranged in a curved manner so as to reflect the curvature of the ribs 64. The apertures 27 are arranged such that a majority of the cavities 63a defined by the ribs 63 contain at least one aperture 27.

To help reduce distortion in particular, some curved ribs 64 extend between the quarter of the caster mounting area 8, 9, 10, 11. As shown in fig. 8, curved ribs 64 extend from most of the mounting points of the caster mounting area, except for the outermost mounting points 8b, 9b, 10b, 11b (due to their location at the outer corners of the quarter-wheel truck 1).

The curved ribs 64 are further particularly advantageous on the quarter-wheel truck 1 of the present invention, as the increased rigidity provided by the curved ribs 64 helps to offset the reduction in structural strength of the quarter-wheel truck 1 due to the deeper wheel receiving sections.

The mounting plates 12a, 12b, 13a, 13b may also help to offset the reduction in structural integrity due to the increased depth of the wheel receiving portion. The mounting plate is typically made of metal, such as steel, and is generally aligned with the wheel receiving portion. However, the mounting points 10, 11 of the swivel casters 7a, 7b are located further inward (in the longitudinal direction) than the mounting points of the fixed casters. As a result, unlike the mounting plates 12a, 12b of the fixed casters, the mounting plates 13a, 13b of the swivel casters 7a, 7b are not perfectly aligned with the wheel receiving portions 21a, 21 b. Thus, the area of the deck 2 containing the wheel receiving portions 21a, 21b for the swivel castors 7a, 7b is provided with more reinforcement than the area of the deck 2 containing the wheel receiving portions 19a, 19b for the rigid castors 6a, 6 b.

In one embodiment, this additional reinforcement is provided by providing more ribs 63, 64 extending from the mounting point of the swivel caster than its corresponding mounting point on the fixed caster. For example, fig. 8 shows that the innermost mounting points 10d, 11d for the swivel castors 7a, 7b have eight ribs extending therefrom. Since the swivel caster is located further inboard (longitudinally) than the fixed caster (see fig. 13), providing a greater number of ribs from the innermost mounting points 10d, 11d of the swivel caster provides greater resistance to deformation in that area of the swivel caster. In contrast, the innermost mounting points 8d, 9d for the fixed castors 6a, 6b do not require as many extending ribs and, in the embodiment shown in fig. 8, have six ribs extending therefrom. Similarly, there are more ribs extending from the mounting points 10c, 11c of the swivel caster than the mounting points 8c, 8d for the fixed caster. In the embodiment shown in fig. 8, the mounting points 10c, 11c of the swivel castors have six ribs extending therefrom, while the mounting points 8c, 9c of the fixed castors have five ribs extending therefrom.

The angle between each extending rib extending from the innermost mounting point is different (for both swivel and fixed casters). The angle between the ribs extending towards the centre of the quarter trolley 1 is substantially smaller than the angle between the ribs extending away from the centre of the quarter trolley 1. For example, two ribs extend from the innermost mounting point 10d in a first quadrant FQ (excluding ribs aligned with the axes of the quadrants) that has an origin at the innermost mounting point 10d and surrounds the center of the trolley 1. In contrast, only one rib extends from the innermost mounting point 10d in the second quadrant SQ (which has an origin at the innermost mounting point 10d and surrounds the outer corner of the trolley 1 closest to the inner mounting point 10 d). The same is true for the other mounting points 8a, 8c, 9a, 9c, 10a, 10c, 11a, 11c, which are not located at the outer corners. In one embodiment, more than two ribs may extend from mounting point 10d into the first quadrant FQ, and no rib may extend from mounting point 10d into the second quadrant SQ.

In another embodiment, further reinforcement around the area of the wheel receiving portions 21a, 21b for the swivel castors 7a, 7b is provided by providing an additional rib 65 under each wheel receiving portion 21a, 21b, the additional rib 65 extending from the front end 4d of the quarter trolley 1 and terminating in a recess 66a, 66b, the recesses 66a, 66b being under a portion of the wheel receiving portions. The additional ribs 65 are arranged to extend at least partially under the wheel receiving portions 21a, 21b and are configured to help reduce stress during an impact on the front portion 4d of the quarter-bogie 1. That is, the additional rib 65 has a first end connected to the other rib 63 and a second end that is not connected to the other rib 65, i.e. terminates in the recesses 66a, 66 b. The second end may be tapered as shown in fig. 13.

The additional ribs 65 may be relatively short compared to the length of the recesses 66a, 66b, thereby saving weight. In one embodiment, the additional ribs 65 may be curved. In another embodiment, the additional ribs 65 may extend entirely within the recesses 66a, 66b, and may alternatively extend the entire length of the wheel receiving pockets 21a, 21 b.

As can be seen from fig. 8, toward the rear end 4c of the truck 1 (the rear end is defined as the side on which the caster 6a, 6b is located), the first curved rib 67 extends between the mounting points 8d and 9d, curving toward the rear end 4 c. A second curved rib 68 having a shallower curvature and curved away from the rear end 4c extends between the mounting points 8a and 9 a. The third curved rib 69 extends between the mounting points 8c and 9c and curves away from the rear end 4 c.

Towards the front 4d of the trolley 1 (the front being defined as the side on which the swivel castors 7a, 7b are located), a fourth curved rib 70 extends between the mounting points 10d and 11 d. A fifth curved rib 71 having a shallower curvature and curved in the opposite direction to the fourth curved rib 70 extends between the mounting points 10a and 11 a. A sixth curved rib 72 extends between mounting points 10c and 11 c.

In other words, the mounting points 8a, 8c, 8d, 9a, 9c, 9d, 10a, 10c, 10d, 11a, 11c, 11d, which are not located at the outer corners of the quarter-bogie 1, are all connected in the width direction to their respective mounting points 8a, 8c, 8d, 9a, 9c, 9d, 10a, 10c, 10d, 11a, 11c, 11d by at least one curved rib.

Mounting point 10d is also directly connected to mounting point 11d by straight rib 73. Since the curvature of the first curved rib 67 is sufficiently shallow, no straight rib is required between the mounting points 8d, 9d of the rigid castors. However, the fourth curved rib 70 connecting the respective mounting points 10d, 11d is deeper because the mounting points 10d, 11d are located at a greater distance from the front end 4d of the quarter trolley 1 than the distance between the mounting points 8d, 9d and the rear 4c of the quarter trolley 1. Thus, the additional straight rib 73 helps to provide further rigidity between the mounting points 10d, 11d of the swivel castor.

The mounting points 8a, 8c, 8d, 9a, 9c, 9d, 10a, 10c, 10d, 11a, 11c, 11d are not located on the outer corners of the quarter-trolley 1, they are also connected lengthwise to their respective mounting points. The mounting point 8a is connected to the mounting point 11a by a seventh curved rib 74. Mounting point 9a is connected to mounting point 10a by an eighth curved rib 75. Mounting point 8d is connected to mounting point 11d by a slightly curved rib 76. The mounting point 9c is connected to the mounting point 10c by a tenth curved rib 77. Mounting point 9d is connected to mounting point 10d by an eleventh curved rib 78. The mounting point 8c is connected to the mounting point 11c by a twelfth curved rib 79.

The ribs 63 and the curved ribs 64 are configured such that there is a greater concentration of ribs in areas where higher stresses may be present, for example towards the centre of the quarter bogie 1. The presence of a greater concentration of ribs at the sides 4a, 4b and ends 4c, 4d of the quarter-trolley 1 also helps to protect the quarter-trolley 1 from impacts. The curved rib 64 is also configured to curve around the location of the securing feature, such as the handle aperture 30 or the slot 33.

At least one curved rib 76-79 extends between the caster mounting areas 8, 9 at one end 4c of the quarter-trolley 1 and the caster mounting areas 10, 11 at the opposite end 4d of the quarter-trolley. This arrangement of ribs may improve the strength of the quarter-trolley. At least one curved rib may extend between the mounting points of the caster mounting area.

The handle holes 30 present areas of reduced structural integrity, particularly along the length of the quarter trolley 1. Thus, the use of a plurality of curved ribs 64 in the region of the handle holes 30 helps to counteract this reduction in structural integrity along the sides 4a, 4b of the quarter-trolley 1.

Fig. 24 is a perspective view of a trolley carrying tray 100 according to an embodiment of the invention. The trolley carrying tray 100 may be used to transport a trolley according to an embodiment of the present invention. The trolley carrying tray 100 is particularly suitable for transporting trolleys having self-centering swivel castors.

The trolley carrying tray 100 includes a trolley receiving layer 102 disposed on top of a tray 104. The tray 104 is shown in an exploded view in fig. 25. As shown in FIG. 25, the pallet 104 includes three longitudinally extending planks 106, two planks disposed on either side of the pallet and one plank extending along the middle of the pallet. These boards constitute the base of the pallet. The blocks 108 are disposed on the planks 106 and, in turn, support a widthwise extending plank 110. Finally, five longitudinally extending planks 112 are disposed on top of the width-wise extending planks 110. The boards 106, 110, 112 may be made of wood. Similarly, the block 108 may be formed of wood. For example, the boards and blocks may be fastened together using nails or screws.

The blocks 108 located at the corners of the tray 104 are longer than conventional blocks. For example, the block may have a length of 200mm or more, and may have a length of 250mm or more. The block may be, for example, about 300mm long. Providing blocks of increased length improves the stability of the trolley receiving layer 102 when used to transport a stack of trolleys (less flexing of the trolley receiving layer will occur).

Fig. 26 depicts the trolley-receiving layer 102 viewed from above, and fig. 27 depicts a cross-section of the trolley-receiving layer 102. Wheel receiving recesses 114, 116 are provided in the trolley receiving floor 102. The wheel receiving recesses 114, 116 (which may also be referred to as wheel recesses) are configured to allow four quarter dollies 1 to be received on the trolley receiving layer 102. This is shown in fig. 28 to 30. The wheel-receiving recesses 114, 116 extend through most of the thickness of the trolley-receiving layer 102, but do not extend through the bottom of the trolley-receiving layer. The trolley receiving layer 102 may be secured to the pallet 104 using screws. Any other suitable securing means (e.g. nails) may be used.

The wheel-receiving recesses 114, 116 are both rectangular when viewed from above. A chamfer 118 is provided at either end of each wheel receiving recess 114, 116. The chamfer 118 is shown as being 45 degrees, but other angles of chamfer may be used. The wheel-receiving recesses 114 provided at the ends of the trolley-receiving floor 102 are shorter than the wheel-receiving recesses 116 provided toward the center of the trolley-receiving floor. The wheel-receiving recesses 114 at the ends of the trolley-receiving layer 102 are configured to receive the rigid castors of a quarter trolley (i.e., castors that are not swivel castors). The casters may be, for example, casters 6a, 6b as depicted and described elsewhere in this document. The wheel-receiving recesses 116 disposed toward the center of the trolley-receiving floor 102 are longer than the wheel-receiving recesses 114 disposed at the ends of the trolley-receiving floor. The wheel-receiving recess 116 provided toward the center of the trolley-receiving floor 102 is configured to receive the swivel caster of a quarter trolley. The swivel castors may for example be swivel castors 7a, 7b as depicted and described elsewhere in this document.

As has been further explained above, the swivel castors of the quarter trolley may include a self-centering mechanism such that when the quarter trolley is lifted from the ground, the swivel castors move to one of two positions. In both positions, the wheels of the swivel castors may be substantially parallel to the edges of the quarter trolley. In the first position, which may be referred to as the outboard position, the axis of the wheels of the caster are closer to the adjacent end of the quarter-trolley than the axis of rotation of the caster. An example of an outboard position is depicted in fig. 9. In another position, which may be referred to as an inboard position, the axis of the wheels is closer to the center of the quarter trolley than the axis of rotation of the caster. An example of the inboard position is depicted in fig. 10. The wheel receiving recess 116 is capable of receiving swivel castors in inboard positions and is also capable of receiving swivel castors in outboard positions (the length of the wheel receiving recess 116 is significantly greater than the diameter of the wheel of a quarter trolley).

The wheel-receiving recesses 114 at the ends of the trolley-receiving layer 102 have a length that is less than the diameter of the wheels of the trolley. The length of these wheel-receiving recesses 114 may generally correspond to the length of a portion of the wheel that is to be received in the wheel recess. Thus, there is a snug fit (snug fit) between the wheels 6a, 6b and the wheel receiving recess 114 (see fig. 29), thereby preventing significant movement of the wheels along the wheel receiving recess. Alternatively, a snug fit may be referred to as a snug fit. The wheel receiving recesses 114 at the ends of the trolley receiving layer 102 precisely position the quarter trolleys lengthwise. This ensures that four quarter trolleys can be placed on the trolley receiving level (which prevents the trolleys from overlapping with the space that should be available for receiving different trolleys).

The wheel-receiving recesses 116 toward the center of the trolley-receiving floor 102 are longer than the wheel-receiving recesses 114 at the ends of the trolley-receiving floor. The wheel-receiving recesses 116 may have a length greater than twice the distance between the axis of the wheel and the axis of rotation of the caster (e.g., greater than 80 mm). The wheel receiving recess 116 toward the center of the trolley is long enough to receive the swivel caster at either the inboard or outboard positions.

The wheel-receiving recesses 116 toward the center of the trolley-receiving layer 102 may have a greater width (e.g., at least 5mm greater, such as 10mm or greater) than the wheel-receiving recesses 114 at the ends of the trolley-receiving layer. This greater width allows for the reception of swivel castors which have an inboard or outboard position which is not completely parallel to the sides of their trolley. This may be due to damage or wear of the castors during use.

The wheel-receiving recess 114 at the end of the trolley-receiving layer 102 has a width slightly greater (e.g., 10mm greater) than the width of the wheel of the rigid caster. These wheel receiving recesses 114 ensure that when the quarter-trolleys are placed on the trolley receiving layer 102, they are positioned precisely in the width direction, thereby ensuring that four quarter-trolleys can be accommodated on the trolley receiving layer. If the widthwise position of the quarter dolly is not precisely controlled by the wheel receiving recesses 114, 116, the dolly already on the dolly receiving layer 102 may overlap with the space that should be occupied by another dolly and may be prevented from being loaded onto the dolly receiving layer.

As described above, the ends of the wheel-receiving recesses 114, 116 may include a chamfer 118. The chamfer is desirable because it allows the quarter-trolley to move into the wheel-receiving recesses 114, 116 if the trolley is slightly misaligned in the longitudinal direction on the trolley-receiving layer 102.

Fig. 28-30 depict four quarter trolleys 1 positioned on the trolley carrying tray 100. The caster of each of the four dollies 1 is received by the dolly carrying tray 100. In these figures, the swivel caster wheels are in the outboard position. However, in practice, some or all of the swivel castors may be in an inboard position.

The wheel-receiving recess 114 for the caster may, for example, have a width of less than 50mm (e.g., about 44 mm). The wheel-receiving recesses may, for example, have a length of less than 100mm (e.g., less than 90mm, such as greater than 80mm) including a chamfered portion. The non-chamfered portions of the wheel-receiving recesses 114 may, for example, have a length of less than 60mm (e.g., less than 50mm, such as greater than 40 mm).

The wheel-receiving recess 116 for the swivel caster may, for example, have a width greater than 50mm (e.g., about 54 mm). The wheel-receiving recesses 116 may, for example, have a length of greater than 150mm (e.g., greater than 160mm, e.g., less than 170mm) including a chamfered portion. The non-chamfered portions of the wheel-receiving recesses 116 may, for example, have a length greater than 110mm (e.g., greater than 120mm, such as less than 140 mm).

The wheel-receiving recesses 114, 116 may, for example, have a depth of 15mm or greater. The wheel receiving recess may for example have a depth of about 20 mm.

The trolley receiving layer 102 may be formed of wood, such as plywood. The plywood may be, for example, marine grade plywood. Alternatively, the trolley receiving layer 102 may be formed of plastic or any other suitable material.

As can be seen in fig. 27, the wheel-receiving recesses 114, 116 are recesses rather than openings through the trolley-receiving layer 102. In an alternative embodiment, the wheel-receiving recess may pass completely through the trolley-receiving floor 102. However, the advantage results from the wheel receiving recess not passing completely through the trolley receiving layer. In particular, the wheel-receiving recesses 114, 116 have a bottom surface on which the wheels of the trolley may rest. This provides improved stability of the trolley on the trolley carrying tray 100 (as compared to the situation where the wheels of the trolley rest on the pallet's planks 112 (which pallets' planks 112 may not be smooth surfaces and/or may not be flat)). The bottom surfaces of the wheel-receiving recesses 114, 116 may be flat.

Although in the embodiments described and illustrated herein, the wheel recesses 114 that receive the rigid castors are located at the ends of the trolley receiving floor 102, in alternative embodiments they may be located toward the center of the trolley receiving floor. Similarly, although in the embodiments described and illustrated herein, the wheel recesses 116 that receive the swivel casters are located toward the center of the trolley receiving floor 102, in alternative embodiments they may be located at the ends of the trolley receiving floor. In another alternative embodiment, some of the wheel-receiving recesses 114 that receive the rigid castors may be located at the ends of the trolley-receiving layer 102 and other wheel-receiving recesses 114 that receive the rigid castors may be toward the center of the trolley-receiving layer.

An advantage of providing the wheel well 116 that receives the swivel caster toward the center of the trolley receiving layer 102 is that the brake of the swivel caster does not protrude outward at the outer edge of the trolley carrying tray 100 (see fig. 29). If the brakes protrude at the outer edge of the trolley carrying tray 100, they may catch a person or object. Although the brakes in fig. 29 appear to be in contact, in reality only one swivel caster is provided with a brake, so the brakes of the swivel casters are offset relative to each other in the width direction of the trolley carrying tray 100.

As described above, the wheel-receiving recesses 114, 116 are rectangular in shape when viewed from above. The wheel-receiving recesses 114, 116 may be referred to as being generally rectangular. Shapes that include a minor deviation from a rectangle may be considered to be generally rectangular. The generally rectangular wheel-receiving recesses should be close enough to rectangular that they cannot receive swivel castors at 45 degrees to the sides of the trolley. Thus, for example, the wheel-receiving recess does not include a semi-circular shape to accommodate a swivel caster at such an angle. Thus, the wheel-receiving recess 116 is configured to receive a swivel caster that is biased toward a rest position where the wheel is oriented along the length of the trolley.

In the illustrated embodiment of the trolley carrying tray 100, the recess 116 receiving the swivel castor wheels 7a, 7b is long enough to receive the swivel castor wheels at either the inboard or outboard positions (these are examples of equilibrium positions). However, as described further above in connection with fig. 18, the swivel casters may be configured such that they have only one equilibrium position (e.g., outboard position). In this case, the length of the swivel caster receiving recess can therefore be shorter. The length of the swivel caster receiving recess may be, for example, substantially the same as the length of the rigid caster receiving recess. However, it is preferred that the recess 116 receiving the swivel caster 7a, 7b is long enough to receive the swivel caster in either an inboard or outboard position (e.g., as shown). This is beneficial because it allows the trolley carrying tray 100 to receive trolleys having swivel castors that may have inboard or outboard positions, and swivel castors that may have only one equilibrium position (e.g., outboard position).

It will be appreciated by those skilled in the art that various modifications could be made to the above-described embodiments without departing from the scope of the invention. Those skilled in the art will also recognize that appropriate portions of any of the embodiments may be used with other embodiments, where appropriate.