阅读说明：本技术 具有升降装置的装载机 (Loader with lifting device ) 是由 E·瓦格纳 S·普兰特 于 2018-11-23 设计创作，主要内容包括：一种装载机(1)具有车架装置,其中,该车架装置具有前车架部分(2)和后车架部分(3)以及安装到后车架部分(3)的操作员驾驶室(7),操作员驾驶室(7)具有前窗(13)和升降装置(17、30),前窗(13)具有下边界(43)；升降装置(17、30)安装到前车架部分(2)。升降装置(17、30)包括主臂(18)、主臂支撑装置(21)和主臂致动元件(24),其中,该主臂(18)在其近端设置有枢轴连接器(19)和设备连接器(20)；主臂支撑装置(21)用于可枢转地支撑主臂(18)的枢轴连接器(19),其中,主臂支撑装置(21)能够按一方向移动,该方向包括至少一个分量位于相对于前车架部分(2)的前后方向上；主臂致动元件(24)用于枢转主臂(18),以使设备连接器(20)能够在下降位置和上升位置之间移动,其中,装载机(1)构造成枢转连接器(19)位于前窗(13)在升降装置(17、30)的操作位置中的下边界(43)的至少一部分(43.1)下方。(A loader (1) having a frame arrangement, wherein the frame arrangement has a front frame part (2) and a rear frame part (3) and an operator cab (7) mounted to the rear frame part (3), the operator cab (7) having a front window (13) and lifting means (17, 30), the front window (13) having a lower border (43); the lifting device (17, 30) is mounted to the front frame part (2). The lifting device (17, 30) comprises a main arm (18), a main arm support device (21) and a main arm actuating element (24), wherein the main arm (18) is provided at its proximal end with a pivot connector (19) and a device connector (20); a main arm support means (21) for pivotally supporting the pivot connector (19) of the main arm (18), wherein the main arm support means (21) is movable in a direction including at least one component in a front-rear direction with respect to the front frame portion (2); the main arm actuating element (24) is used for pivoting the main arm (18) to enable the equipment connector (20) to move between a lowered position and a raised position, wherein the loader (1) is configured such that the pivoting connector (19) is located below at least a portion (43.1) of a lower boundary (43) of the front window (13) in the operating position of the lifting device (17, 30).)

1. A loader (1) having a frame arrangement comprising a front frame part (2) and a rear frame part (3), the loader comprising:

an operator cab (7), said operator cab (7) being mounted to said rear frame portion (3), said operator cab (7) having a front window (13) with a lower boundary (43);

-a lifting device (17, 30), said lifting device (17, 30) being mounted to said front frame part (2), comprising:

a main arm (18) provided with a pivot connector (19) at a proximal end thereof and a device connector (20) at a distal end thereof;

-a main arm support means (21) for pivotably supporting the pivot connector (19) of the main arm (18), wherein the main arm support means (21) is movable in a direction comprising at least one component in a forward-backward direction with respect to the front frame part (2);

a main arm actuating element (24) for pivoting the main arm (18) such that the device connector (20) is movable between a lowered position and a raised position;

wherein the loader (1) is configured such that the pivot connector (19) is located below at least a portion (43.1) of the lower boundary (43) of the front window (13) in the operational position of the lifting device (17, 30).

2. Loader (1) according to claim 1 wherein the pivot connector (19) is located below at least a part (43.1) of the lower boundary (43) of the front window (13) in an intermediate position of the lifting device (17, 30) wherein the main arm (18) is horizontally oriented.

3. Loader (1) according to claim 1 or 2 wherein the pivot connector (19) is located below at least a part (43.1) of the lower border (43) of the front window (13) in all operating positions of the lifting device (17, 30).

4. A loader (1) according to claim 1, 2 or 3 wherein the pivot connector (19) is located below the entire lower boundary (43) of the front window (13).

5. Loader (1) according to any of the preceding claims wherein the main arm support (21) is located completely below the portion (43.1) of the lower border (43) of the front window (13) in the operating position.

6. A loader (1) according to any of the preceding claims wherein the front frame section (2) and the rear frame section (3) are interconnected in an articulated manner to provide articulated steering.

7. A loader (1) according to any of the preceding claims wherein the loader is a wheel loader.

8. Loader (1) according to any of the preceding claims, wherein the lifting device (17) comprises a guiding device (23), which guiding device (23) engages with the main arm (18) at a guiding portion (22) of the main arm (18) between the pivot connector (19) and the equipment connector (20), wherein the guiding device (23) guides the main arm (18) such that the equipment connector (20) follows a predetermined path when pivoting the main arm (18) between the lowered position and the raised position.

9. The loader (1) of any one of claims 1 to 7 further comprising an auxiliary actuation element (31), a determination device and a control device, wherein the auxiliary actuation element (31) is engaged with the main arm (18) and the main arm support device (21) to adjust the angle between the main arm (18) and the main arm support device (21); -said determination means are adapted to determine a lifting related quantity reflecting the position of said equipment connector (20) relative to said front frame part (2); and control means for controlling the operation of the main arm actuator element (24) and the auxiliary actuator element (31) based on the determined lifting-related amount so that a path when the device connector (20) moves between the lowered position and the raised position follows a predetermined path.

10. Loader (1) according to one of the preceding claims, wherein the lifting device (17, 30) is configured to move the equipment connector (20) along a substantially vertical path between the lowered position and the raised position.

11. Loader (1) according to any of the preceding claims wherein the operator cab (7) comprises an operator seat aligned with the front window (13) so that when an operator is seated in the intended manner on the operator seat, the operator is looking straight through the front window (13), wherein the loader (1) is configured so that the pivot connector (19) is located outside the central view of the operator when seated in the intended manner on the operator seat in all operating positions (17, 30) of the lifting device.

Technical Field

The present invention relates to a loader having a rear frame section and a front frame section, wherein an operator cab is mounted to the rear frame section; the front frame portion supports the lifting device. The lifting means may be a vertical lifting means for moving the apparatus along a substantially vertical path between a lowered (lowered) position and a raised (lifted) position.

Background

Loaders typically include a front bucket for scooping loose material (e.g., soil, sand, or gravel) from the ground and then moving it from one location to another without pushing the material across the ground. The loader can be used to move the stacked material from the ground and put it into a waiting dump truck.

Loaders typically include a lift device for moving the bucket from a lowered position to a raised position. Conventional lifting devices include a main arm having a pivot connector mounted on the loader frame and a device connector; the implement coupler is used to mount the bucket to the hoist. The implement coupler moves along a substantially arcuate path as the main arm moves between the lowered position and the raised position as the main arm rotates about a point fixed in space relative to the load carriage means. Such lifting devices are referred to as radial lifting devices.

Recently, vertical lift devices for loaders have been proposed. The vertical lift device comprises a main arm support device and a main arm with a pivot connector, wherein the main arm support device is pivotally mounted on a frame of the loader; the main arm with the pivotal connector is mounted to the main arm support means. The main arm support means may adjust the rotation point of the main arm to provide a movement path of the device connector between the lowered and raised positions that deviates from the arc-shaped path. Such a vertical lift device is known from WO 2016/123732a1 and WO 2016/123735 a 1.

Disclosure of Invention

The present invention relates to a loader having a frame arrangement with a front frame section and a rear frame section. The front frame portion and the rear frame portion may be regions of a single assembly. Alternatively, the front frame portion and the rear frame portion may be separate components or parts, which may be connected to each other. The connection may be configured such that the two parts are movable relative to each other. The front frame section is located forward of the rear frame section in the forward direction of movement of the loader. The front frame portion may support the front wheels and/or the rear frame portion may support the rear wheels of the loader. Additionally or alternatively, the loader may be a track loader. The front frame portion may support a front track and/or the rear frame portion may support a rear track of the loader. Further, the front and rear frame portions of the loader may together support a pair of tracks.

The loader includes an operator cab mounted to the rear frame portion. Optionally, the operator cab is immovably mounted to the rear frame portion. The operator cab may include a front wall, two side wall members and/or a rear wall member. At least one of the enclosures, for example one of the side enclosures, may constitute or may include a door to access the cab. The cab may house an operator's seat and controls for operating the loader. These control means may comprise control means for operating the working hydraulic pressure and/or control means for steering and/or control means for driving the loader.

The loader may comprise a longitudinal axis of symmetry. The longitudinal axis of symmetry may be directed towards the direction of movement of the loader when the loader is moved straight forward and may be parallel to the ground, i.e. the contact surface of the loader with the wheels and/or tracks of the ground. The longitudinal axis of symmetry may be symmetrical with respect to the design of the loader, in particular with respect to the wheels and/or the tracks when the loader is moved straight ahead. The lifting device and/or one or more components thereof may be symmetrical or asymmetrical with respect to the longitudinal axis of symmetry. The longitudinal direction of the loader is aligned with the longitudinal axis of symmetry and the transverse direction of the loader is perpendicular to the longitudinal axis of symmetry and parallel to the ground. The vertical or height direction of the loader is generally towards ground level.

The operator cab includes a front window. The front window may be provided at the front wall element. The front window may exhibit curvature or may be completely planar. The longitudinal axis of symmetry of the loader may be at a 90 angle to the front window when the loader is moving forward. Alternatively, the longitudinal axis of symmetry is generally oriented toward the front window when the loader is moved straight forward. The front window includes a lower boundary. The lower boundary delimits the front window downwards, i.e. towards the ground. The lower boundary extends along the entire front window in the lateral direction of the loader. The design of the lower boundary may be symmetrical with respect to the longitudinal symmetry axis of the loader.

In addition, the loader further comprises a lifting device mounted to the front frame section. The lifting device comprises a main arm, a pivot connector is arranged at the near end of the main arm, and an equipment connector is arranged at the far end of the main arm. Equipment (e.g., buckets and/or pallet forks) may be mounted to the equipment connectors. Further, the lifting device includes a main arm supporting device for pivotably supporting the pivot connector of the main arm. The main arm may be pivotally mounted to the main arm support means by a pivot connector. Further, the main arm support may be pivotally mounted to a front frame portion of the loader, such as to a frame of the front frame portion. The main arm support device is movable in a direction including at least one component in a front-rear direction with respect to the front frame portion.

Further, the lifting device further comprises a main arm actuating element for pivoting the main arm in order to move the device connector between the lowered position and the raised position. In the context of the present invention, the lowered position is preferably the lowest position of the appliance connector in normal operating conditions of the lifting device. Further, preferably, the raised position of the equipment connector is the highest position of the equipment connector under normal operating conditions of the lifting device. The pivot point of the main arm may be used to provide a path of movement of the device connector between the lowered position and the raised position that deviates from the arcuate path by the main arm support means. For example, a substantially vertical movement path may be achieved. The substantially perpendicular path may include perpendicular, J-shaped, and/or tangent planes of different curvature. The substantially vertical path may be a J-shaped path, wherein the device connector may move from a lowered position to a raised position, up and forward, and then substantially only up in an initial raising phase. In the context of the present invention, a substantially vertical path is a path that takes into account the overall verticality of the current context. The path may deviate from a strictly vertical path without affecting its substantial verticality. In other words, the substantially vertical path is not a substantially arcuate path.

The loading mechanism according to the invention results in the pivotal connector of the main arm being located below at least a part of the lower boundary of the front window in the operating position of the lifting device. In other words, in a direction perpendicular to the ground (i.e. the vertical direction of the loader), the pivot connector is located below at least a portion of the lower boundary of the front window in said operating position. Thus, in the operative position, the pivot connector is closer to the ground than the portion of the lower boundary. This is achieved by matching the geometric design of the operator's cab to the front window and the lifting device, so that the above-mentioned geometric relationship is achieved in the operating position.

The present invention provides a loader having a lift that can make a non-arcuate lifting path that provides good visibility for the operator. In particular, by moving the main arm support means mainly in the region below the lower boundary of the front window, it does not enter the field of view through the front window significantly, and therefore does not reduce visibility.

According to an embodiment, the loading mechanism causes the pivot connector to be located below said portion of the lower boundary of the front window in the intermediate position of the lifting device. In the neutral position of the lifting device, the main arm (e.g. the line through the pivot connector and the device connector) is oriented horizontally, i.e. parallel to the ground. This embodiment provides a good compromise between visibility and other machine specifications, such as dump height and dump range.

The pivot connector may be located below said portion of the lower boundary of the front window in all operating positions of the lifting device. In other words, the pivotal connector remains below the portion of the lower boundary at all times while pivoting the lifting device from the lowered position to the raised position. This embodiment provides very good visibility for the loader because the pivot connector never enters the field of view through the front window. Additionally or alternatively, the pivot connector may also be located below the entire lower boundary of the front window in a single or all operating positions of the lifting device. This also improves visibility.

According to an embodiment, the entire main arm support means is located below said portion of the lower boundary of the front window in the intermediate position. Thus, any components supported by the master arm do not detract from the operator's field of view.

The front and rear frame portions of the loader may be hingedly interconnected to provide articulated steering. Articulated steering may be provided by an articulation support and one or more steering actuators (e.g., hydraulic actuators) that may effect relative displacement of the front and rear frame portions with respect to each other. The loader may be a wheel loader.

Further, according to an embodiment, the lifting device comprises a guiding means engaging with the main arm at a guiding portion of the main arm between the pivot connector and the device connector, wherein the guiding means guides the main arm such that the device connector follows a predetermined path when the main arm is pivoted between the lowered position and the raised position. This embodiment may provide a non-arcuate lifting path in an absolutely mechanical and robust manner.

Alternatively, the non-arcuate path of ascent and descent may be provided by a secondary actuation element engaged with the primary arm and the primary arm support means to adjust the angle therebetween, determination means and control means; the determining device is used for determining a lifting related quantity reflecting the position of the equipment connector relative to the frame device; and the control means is for controlling the operation of the main arm actuating element and the auxiliary actuating element based on the determined lifting-related amount. The control of the actuating element may cause a path of the device connector as it moves between the lowered position and the raised position to follow a predetermined path. This embodiment may provide various non-arcuate lifting paths using a single machine.

According to an embodiment, the lifting device is configured to move the device connector along a substantially vertical path between the lowered position and the raised position. This may reduce the maximum distance of the equipment connector from the center of gravity of the construction machine when moving the equipment between the lowered position and the raised position. Thus, for a given machine operating weight, the maximum lifting capacity can be increased.

According to one embodiment, the operator cab includes an operator seat aligned with the front window. This alignment allows the operator to sit in the operator's seat in the desired manner, looking straight ahead through the center of the front window, without having to turn his body or move his head or eyes. The loader may be configured so that the pivot connector is located outside the central field of view in all operating positions of the lift when the operator is seated in the operator's seat in the desired manner described above. In the context of the present invention, the field of view of the operator may be understood as the area that the operator can see, while keeping the head still, looking forward, without moving the eyes. The central field of view may be that portion of the field of view that is visibly observable. The operator may be an average height operator. The height of the operator may be between 1.50 and 2.10 meters, for example between 1.70 and 1.95 meters. This embodiment provides good visibility because the pivot connector does not enter the central field of view of the operator.

Drawings

Fig. 1 shows a side view of a loader with a lifting device according to an embodiment of the invention in a lowered position.

Fig. 2 shows a side view of the loader of fig. 1 in an intermediate position.

Fig. 3a-3c schematically show the front window and the lifting device of the loader of fig. 1-2 from the perspective of an operator.

Fig. 4a-4c show the lifting device of fig. 1-3 in different positions to explain its function.

Fig. 5a-5c show another construction of a lifting device, wherein the loader of fig. 1-3 has a lifting device that can be arranged in different positions for explaining its function.

Detailed Description

Fig. 1 shows a loader 1 according to the invention in a simplified side view. Elements not essential to the present invention are omitted. The loader 1 comprises a front frame section 2 and a rear frame section 3. A pair of front wheels 4 are mounted on the front frame portion 2 and a pair of rear wheels 5 are mounted on the rear frame portion 3.

An engine compartment 6 is provided in the rear frame section 3. The engine compartment 6 houses one or more power sources to provide the power sources required to operate the loader 1. These power sources may include, but are not limited to, internal combustion engines (e.g., diesel engines) that may be connected to further equipment (e.g., hydraulic pumps, generators, etc.). In addition, the power source may also include a battery and an electric motor. The power source is used to provide power to drive the front wheels 4 and/or the rear wheels 5, as well as to power actuators of the construction machine 1. For example, the actuator may be an actuator of a lifting device and/or a steering device.

Furthermore, the loader 1 comprises an operator's cab 7 mounted on the rear frame section 3. Within the operator's cab 7, space for the operator is provided, as well as required operating and control elements (not shown) which can be used by the operator. The operator cab 7 includes an operator seat (not shown). The operator's cab 7 includes a rear wall 8, two opposing side walls 9 (opposite each other) and a front wall 12. At least one side wrapping 9 includes a door 11 for access to the operator's cab 7. The front wall 12 of the operator's cab 7 includes a front window 13. In this embodiment the front window 13 extends from one side gusset element to the other opposite side gusset element 9 across the entire transverse direction of the loader 1. The front window 13 is arranged symmetrically with respect to the longitudinal symmetry axis of the loader 1. In the present embodiment, the front window 13 includes a laterally curved profile.

The front frame section 2 is mounted to the rear frame section 3 by means of an articulated steering arrangement 14. The articulated steering device 14 comprises a plurality or two (optional) bearings 15, 16, said bearings 15, 16 being located above each other for providing an articulated mounting between the front frame part 2 and the rear frame part 3. The hinge-mounted pivot axis X (i.e. the pivot axis of the supports 15, 16) is arranged substantially along the vertical axis of the loader 1. Alternatively, the pivots of the supports 15, 16 are coaxial with each other. The steering device 14 may be disposed below the operator's cab 7, for example, directly below the cowl 12.

The articulated steering arrangement 14 provides tilting between the front frame section 2 and the rear frame section 3 to provide steering by varying the angle between the front frame section 2 and the rear frame section 3 in a plane parallel to the ground. The articulated steering device 14 may be driven by one or more actuators (e.g., hydraulic actuators), not shown. The hydraulic actuator may be driven by the power source of the engine compartment 6. During steering operation, the front frame section 2 is inclined with respect to the rear frame section 3 and thus with respect to the operator's cab 7 and the engine compartment 6, which are provided at the rear frame section 3.

Furthermore, the loader 1 comprises a lifting device 17. The lifting device 17 comprises a main arm 18 and a device connector 20, the proximal end of the main arm 18 having a pivot connector 19. The pivot connector 19 is pivotally supported by a main arm support means 21, which in this embodiment comprises a main arm support link. The main arm support link 21 has a first end pivotally connected to the pivot connector 19 of the main arm 18 and a second end pivotally connected to an element of the frame of the front frame section 2. The arrangement of the main arm support link 21 is such that the rotational or pivotal motion of the main arm support link 21 provides movement of the first end in a direction including at least a component in the front-rear direction of the construction machine 1.

The main arm 18 includes a guide portion 22, which is shown in fig. 2 and 4a-4c and is disposed between the pivot connector 19 and the device connector 20. In the present embodiment, the guide portion 22 is offset by a predetermined amount from the line connecting the pivot connector 19 and the device connector 20. The lifting device 17 further comprises a guiding device 23, said guiding device 23 comprising a guiding arm having a first end and a second end. A first end pivotally mounted to an element of the front frame section 2 and a second end pivotally mounted to the main arm 18 of the guide section 22.

The lifting device 17 comprises an actuator 24. The actuator 24 is pivotally mounted at a first end to the front frame section 2 and at a second end to the main arm 18. In the present embodiment, the actuator 24 is a linear actuator, such as a hydraulic actuator, but not limited thereto. The distance between the first end and the second end may be varied when operating the actuator 24, for example by introducing pressurized liquid into a pressure chamber of the actuator 24.

A bucket 25 is also provided on the implement coupling 20 of the main arm 18, to illustrate an implement that can be attached to the main arm 18. The bucket includes a main arm connector for connecting to the implement connector 20 of the main arm 12 and a tilt connector 26 for tilting the bucket. The tilt connector 26 may be disposed above the main arm connector. The tilt connector 26 of the bucket 25 is connected to a tilt device for tilting the bucket 25. The tilting means comprise a lever 27 which is pivotally supported in the centre of the main arm 18. The top end 28 of the operating lever 27 is connected to a tilt cylinder 29, the other end of which is supported on the main arm 18 near the pivot connector 19. The bottom end of the joystick 20 is connected to a tilt connector 26 of the bucket 25 by a link (not shown). Due to the obliquely arranged Z-bar construction, extending the cylinder 29 will cause the bucket to roll back and vice versa. However, other tilt arrangements are also contemplated.

Next, the operation of the lifting device 17 will be explained with reference to fig. 4a-4 c. In fig. 4a, the lifting device 17 is shown in a lowered position. In this case, the main arm 18 is rotated downward. This is achieved by retracting the actuator 24, the actuator 24 being used to operate the main arm 18. The position of the main arm 18 is determined by the link between the guide arm 23 and the main arm support link 21. In other words, the position of the pivotal connector 19 of the main arm 18 can be changed by changing the rotational position of the main arm support link 21, while the guide arm 23, due to its rotational connection between the front frame part 2 and the guide part 22 of the main arm 18, makes it possible to determine the position of the pivotal connector 19 according to the rotational position of the main arm 18. Thus, the lifting device provides a linkage-based transmission that determines the position of only the main arm 18.

Upon actuation of the actuator 24, the main arm 18 is rotated in a clockwise direction in fig. 4a, moving it to the position shown in fig. 4 b. By this rotation, the main arm 18 rotates relative to the main arm support link 21. At the same time, the guide arm 23 rotates in the counterclockwise direction. When the guide arm 23 is rotated in the counterclockwise direction, the guide portion 22 of the main arm 18 is forced along a circular path because the distance between the first end and the second end of the guide arm 23 is constant. It can be seen that the position of the second end of the guide arm 23 moves as the assembly moves rearwardly relative to the loader 1. In the same case, the main arm 18 is rotated in the clockwise direction, and the device connector 20 is raised by a predetermined amount. Since the guide portion 22 of the main arm 23 is urged rearward by a predetermined moving path of the second end of the guide arm 23, the main arm support link 21 rotates in the clockwise direction about the second end thereof mounted on the front frame portion 3. Thus, the position of the first end of the main arm support link 21 moves together with the pivot connector 19 of the main arm 18 rearward relative to the loader 1.

Upon further operation of the actuator 24, the main arm 18 is rotated further in the clockwise direction and reaches the raised position shown in fig. 4 c. In this position, the device connector 20 of the main arm 18 reaches a position higher than the position shown in fig. 4 b. When the main arm 18 is further rotated in the clockwise direction, the guide arm 23 is further rotated in the counterclockwise direction, and the guide portion 22 of the main arm 18 is further rotated along the circular path. When the second end of the guide arm 23 is moved forward relative to the position shown in fig. 4b, the main arm support link 21 is rotated in a counterclockwise direction from the position shown in fig. 4 b. Thus, the position of the first end of the pivot connector 19 supporting the main arm 18 is further forward than the position shown in fig. 4 b.

Based on the above operation, bucket 25 may move along a substantially vertical path from the lowered position shown in FIG. 4a, through the position shown in FIG. 4b, and to the raised position shown in FIG. 4 c. In particular, the path deviates from an arc-shaped or circular path, which may be achieved by means of a radial lift arrangement, wherein the pivot connector of the main arm is immovable and fixed relative to the frame portion of the loader 1.

The lifting device 17 attached to the front frame section 3 of the embodiment of the present invention may also be configured differently. Next, a second construction 30 of the lifting device will be described with reference to fig. 5a-5 c. The lifting device 30 shown according to the second configuration is configured as a lifting device of the first configuration described above, except for the differences outlined below. Like elements are denoted by like reference numerals.

The second configuration of the lifting device 30 does not comprise a guide arm 23, but an auxiliary actuating element 31, which in the embodiment is a linear actuator. The auxiliary actuating element 31 has a first end pivotally mounted to the main arm support link 21 and a second end. A second end of the auxiliary actuating element 31 is pivotably mounted to the main arm 18. The purpose of the auxiliary actuating element 31 is therefore to vary the inclination angle between the main arm support link 21 and the main arm 18. In other words, by extending the auxiliary actuating element 31, the angle enclosed by the main arm support link 21 and the main arm 18 increases.

The second configuration of the lifting device 30 further comprises a control system and determination means for determining a lifting related quantity that is reflective of the position of the equipment connector 20 relative to the front frame part 2. The determination means may comprise a sensor providing relevant information for the extended position of the linear actuators for the primary and secondary actuating elements. The type of sensor can be selected as desired as long as it is able to provide information on the relative position of the main arm 18 with respect to the main arm support link 21 and the relative position of the main arm support link 21 with respect to the front frame section 2. The control system communicates with an output section for controlling the drive system of the lifting device, in particular the main arm drive element 24 and the auxiliary drive element 31.

According to the present embodiment, the control system provides a relationship between the movement of the main arm actuating element 24 and the movement of the auxiliary actuating element 31. In other words, the functions or modes included in the control system include the relationship between the operating position of the main arm actuating element 24 and the operating position of the auxiliary actuating element 31. This relationship may be continuous.

The operation of the lifting device based on the control is explained as follows. Starting from the state in fig. 5a, the operator manipulates an operating element (not shown) in order to initiate a lifting operation to lift the device connector 20 from the lowered position shown in fig. 5a through the position shown in fig. 5b to the raised position shown in fig. 5 c. By the lifting device 30 shown in fig. 5a, the main arm actuator element 24 is extended to turn the main arm 18 and the main arm support link 21 in the clockwise direction in the drawing. During operation of the primary arm actuating element 24, the secondary actuating element 31 is retracted, as shown by a comparison of fig. 5a and 5 b. Upon such retraction of the auxiliary actuating element 31, the angle between the main arm 18 and the main arm support link 21 decreases and the pivot connector 19 retracts in a rearward direction relative to the frame arrangement.

After further performing the lifting operation from the position shown in fig. 5b, the main arm actuator element 24 is further expanded to further rotate the main arm 18 in the clockwise direction in the drawing. During the lifting operation between the position shown in fig. 5b to the lifting position shown in fig. 5c, the auxiliary actuating element 31 is extended again to increase the angle between the main arm 18 and the main arm support link 21. In this way the pivot connector 19 can be moved forward relative to the frame arrangement.

The above-described fitting is to combine the main arm actuator element 24 and the auxiliary actuator element 31 with the configuration using the main arm support link 21, based on which the movement pattern of the device connector 20 can be provided that deviates from an arc-shaped or circular path having a constant radius. Based on the above operation, the bucket can be moved from the lowered position shown in fig. 5a to the raised position shown in fig. 5c through a substantially vertical path shown in fig. 5 b. The closed-loop control can be continuously performed by the control system using the information received from the determination means, so that there is always a unique relationship between the extended position of the main arm actuator element 24 and the extended position of the auxiliary actuator element 31. Other lifting devices may be provided in addition to the lifting devices 17, 30 described above.

Fig. 3a-3c schematically show the front window 13 and the lifting device 17 of the loader 1 of fig. 1 and 2 in different operating positions of the lifting device 17 from the perspective of an operator sitting in the operator's cab 7. In fig. 3a, the lowered position of the lifting device 17, in fig. 3b the intermediate position of the lifting device 17, and in fig. 3c the raised position of the lifting device 17 is shown. Alternatively, the loader 1 may comprise a lifting device 30 as shown in fig. 5a-5 c.

The front window 13 includes an upper boundary 40, a left boundary 41, a right boundary 42, and a lower boundary 43. As shown in fig. 3a-3c, the upper boundary 40 and the lower boundary 43 extend from the left side boundary 41 to the right side boundary 42. In the present embodiment, the upper boundary 42 is disposed entirely at a fixed height position of the loader 1. In other words, the upper boundary 42 does not exhibit any kind of curvature in the vertical direction of the loader 1. Furthermore, in the present embodiment, the two side boundaries are arranged entirely at a constant lateral position of the loader 1. In other words, the two side boundaries 42, 43 do not exhibit any curvature in the transverse direction of the loader 1. In the present exemplary embodiment, the lower boundary 43 is designed symmetrically with respect to the longitudinal axis of symmetry of the loader 1. The lower border 43 comprises a fixed height section 43.1, which extends completely at a fixed vertical height of the loader 1. In the vicinity of the fixed height portion 43.1, both sides of the lower border 43 of the front window 13 comprise a recessed portion 43.2 and 43.3 to improve visibility of the area below the operator's cab 7. In the transverse direction of the loader, the recesses 43.2 and 43.3 extend from the fixed height section 43.1 to the side borders 41 and 42, respectively. Each recess 43.2, 43.3 presents a contour in the vertical direction of the loader 1 with two line segments, which face each other to form a corner. Thus, the recessed portions 43.2, 43.3 of the lower border 43 of the front window 13 are not located completely at a fixed vertical height of the loader 1, but present a profile with a different vertical height.

As shown in fig. 3a-3c, the loader 1 according to the present embodiment is configured such that the pivot connector 19 is located below the fixed height section 43.1 of the lower boundary 43 where the front window 13 is held in all operating positions of the lifting device 17 of the loader 1. Therefore, the main arm support 21 is also located below the fixed height section 43.1 of the front window 13 in all operating positions of the lifting device 17. To this end, the geometric design of the operator's cab 7 (e.g., the cowl 12 with the window 13) and the lifting devices 17, 30 (e.g., the pivotal connectors 19 and the movement paths of the main arm support devices 21) may be matched to each other so as to satisfy the above conditions. Alternatively, the loader 1 may be configured so that the pivot connector 19 remains below the fixed height section 43.1 only in the intermediate position shown in fig. 3 b. It is also conceivable to configure the loader 1 such that the pivot connection 19 remains below the entire lower boundary 43 (i.e. the fixed height section 43.1 and the recessed sections 43.2, 43.3) in all operating positions of the lifting devices 17, 30.