阅读说明：本技术 一种具有顶升及换向功能的穿梭车 (Shuttle with jacking and switching-over functions ) 是由 段群芳 江仲 王文赞 于 2020-12-14 设计创作，主要内容包括：本发明涉及一种具有顶升及换向功能的穿梭车,包括固定框、活动框、顶板和顶升及换向机构,固定框的两端分别可转动的向下凸出安装有朝向其两侧滚动行走的X向行走轮组,顶板设有两个,并分别水平设置于固定框的两侧上方,活动框安装于固定框中,活动框的两侧分别可转动的向下凸出安装有朝向其两端滚动行走的Y向行走轮组,顶升及换向机构安装在固定框上,并分别与两个顶板和活动框传动连接,顶升及换向机构用于分别驱使两个顶板同步上下移动,以及驱使活动框带动Y向行走轮组相对于X向行走轮组上下交错移动。优点:结构设计合理,物料顶升与车体的换向使用一套动力系统,能够降低穿梭车在顶升和换向时的制造成本,结构更简单。(The invention relates to a shuttle vehicle with jacking and reversing functions, which comprises a fixed frame, two movable frames, a top plate and jacking and reversing mechanisms, wherein X-direction travelling wheel groups which roll towards two sides of the fixed frame are respectively and rotatably and convexly arranged at two ends of the fixed frame downwards, the two top plates are respectively and horizontally arranged above two sides of the fixed frame, the movable frames are arranged in the fixed frame, Y-direction travelling wheel groups which roll towards two ends of the movable frames are respectively and rotatably and convexly arranged at two sides of the movable frames downwards, the jacking and reversing mechanisms are arranged on the fixed frame and are respectively in transmission connection with the two top plates and the movable frames, and the jacking and reversing mechanisms are used for respectively driving the two top plates to synchronously move upwards and downwards and driving the movable frames to drive the Y-direction travelling wheel groups to vertically and staggeredly. The shuttle car has the advantages that the structural design is reasonable, a set of power system is used for jacking materials and reversing the car body, the manufacturing cost of the shuttle car during jacking and reversing can be reduced, and the structure is simpler.)

1. The utility model provides a shuttle with jacking and switching-over function which characterized in that: including fixed frame (1), movable frame (2), roof (3) and jacking and reversing mechanism (4), the both ends of fixed frame (1) are rotatable downward protrusion respectively and are installed and roll the X of walking to walking group (5) towards its both sides, roof (3) are equipped with two to respectively the level set up in the both sides top of fixed frame (1), movable frame (2) install in fixed frame (1), and can reciprocate for fixed frame (1), the both sides of movable frame (2) are rotatable downward protrusion respectively and are installed and roll the Y of walking to walking group (6) towards its both ends, jacking and reversing mechanism (4) are installed on fixed frame (1), and respectively with two roof (3) and movable frame (2) transmission are connected, jacking and reversing mechanism (4) are used for ordering about two respectively roof (3) reciprocate in step, and driving the movable frame (2) to drive the Y-direction walking wheel set (6) to move up and down in a staggered manner relative to the X-direction walking wheel set (5).

2. The shuttle car with the functions of jacking and reversing according to claim 1, wherein: the fixed frame (1) is of a cuboid frame structure, the frames at two ends of the fixed frame are respectively and rotatably provided with downward convex X-direction walking wheel sets (5) and are corresponding to the movable frame (2) which is of a cuboid structure, and Y-direction walking wheel sets (6) are respectively located outside two sides of the fixed frame (1).

3. The shuttle car with the functions of jacking and reversing as claimed in claim 2, wherein: any one end of the fixed frame (1) is provided with a plurality of groups at intervals, the X-direction walking wheel set (5) is arranged on any one side of the fixed frame (1) at intervals, and the Y-direction walking wheel set (6) is arranged on any one side of the fixed frame at intervals.

4. The shuttle car with the functions of jacking and reversing according to any one of claims 1 to 3, wherein: jacking and reversing mechanism (4) are including transmission shaft (41), actuating mechanism (42) and two cam drive assembly, transmission shaft (41) level sets up between the middle part of the both sides frame of fixed frame (1), and its both ends stretch into respectively in the both sides frame of fixed frame (1), and rotate with both sides frame respectively and be connected, actuating mechanism (42) are installed in fixed frame (1), and with transmission shaft (41) are connected, be used for ordering about transmission shaft (41) are rotatory around its self axis, two cam drive assembly are equipped with two sets ofly, and distribute in the both ends of transmission shaft (41), every group two cam drive assembly all include at least one transmission unit, transmission unit includes main shaft (43), jacking cam (44) and reversing cam (45), main shaft (43) rotatable install in the corresponding side frame of fixed frame (1), and extend towards the directions of two sides of the fixed frame (1), the jacking cam (44) and the reversing cam (45) are respectively arranged on the main shaft (43), the phase angles of the jacking cam and the reversing cam are different, the upper part of the jacking cam (44) is provided with a jacking roller (46) in rolling contact with the jacking cam, the lower part of the reversing cam (45) is provided with a reversing roller (47) in rolling contact with the reversing cam, the jacking roller (46) is arranged at the lower end of the top plate (3) at the corresponding side through a jacking roller seat (461) in rotating connection with the jacking roller, the reversing roller (47) is arranged on the movable frame (2) through a reversing roller seat (471) in rotating connection with the reversing roller, two ends of the transmission shaft (41) are respectively in transmission connection with the main shaft (43) of the transmission unit at the corresponding side so as to synchronously drive the main shaft (43) to rotate around the axis of the main shaft, and a position between the top plate (3) and the side frame (1 With the first spacing subassembly (7) of corresponding jacking cam (44) in close contact with, activity frame (2) with be connected with between the fixed frame (1) and be used for making switching-over gyro wheel (47) and switching-over cam (45) in close contact with's second spacing subassembly (8).

5. The shuttle car with the functions of jacking and reversing as claimed in claim 4, wherein: each group of double-cam transmission assemblies comprises two transmission units, and the two transmission units are distributed on two side directions of the corresponding end of the transmission shaft (41).

6. The shuttle car with the functions of jacking and reversing according to claim 5, wherein: the two ends of the transmission shaft (41) are coaxially provided with main chain wheels, the main shaft (43) is provided with auxiliary chain wheels (431) corresponding to the chain wheels, and chains (412) meshed with the main chain wheels and the auxiliary chain wheels (431) are wound around the main chain wheels and the auxiliary chain wheels.

7. The shuttle car with the functions of jacking and reversing as claimed in claim 4, wherein: actuating mechanism (42) are including speed reducer (421) and driving motor (422), speed reducer (421) are installed through the mounting bracket the inboard of fixed frame (1) arbitrary one side frame, the motor shaft of driving motor (422) with the input shaft of speed reducer (421), the output shaft of speed reducer (421) with transmission shaft (41) are parallel, and the two is coaxial respectively and is equipped with corresponding drive sprocket, two drive sprocket has around transmission chain (423) outward jointly.

8. The shuttle car with the functions of jacking and reversing as claimed in claim 4, wherein: first spacing subassembly (7) are equipped with four groups, and set up respectively in every the lower extreme of roof (3), first spacing subassembly (7) all include first guiding axle (71), first guide holder (72) and first elastic component (73), first guiding axle (71) upper end with correspond the lower extreme of roof (3) is connected fixedly, install first guide holder (72) correspond in the corresponding side frame of fixed frame (1) the position of first guiding axle (71), first guiding axle (71) lower extreme passes correspondingly first guide holder (72) to be equipped with first stopper (74) in lower extreme tip, first elastic component (73) are connected in corresponding between first guide holder (72) and first stopper (74).

9. The shuttle car with the functions of jacking and reversing as claimed in claim 4, wherein: four groups of second limiting components (8) are arranged and are respectively arranged at the two ends of any side of the movable frame (2) corresponding to the positions of the side frames of the fixed frame (1), the second limiting assemblies (8) respectively comprise a second guide shaft (81), a second guide seat (82) and a second elastic piece (83), the lower end of the second guide shaft (81) is fixedly connected with the corresponding position of the upper end of the movable frame (2), the second guide seat (82) is arranged in the corresponding side frame of the fixed frame (1) at a position corresponding to the second guide shaft (81), the upper end of the second guide shaft (81) passes through the corresponding second guide seat (82), and a second limit block (84) is arranged at the end part of the upper end, and the second elastic piece (83) is connected between the corresponding second guide seat (82) and the second limit block (84).

Technical Field

The invention relates to the technical field of logistics storage, in particular to a shuttle car with jacking and reversing functions.

Background

The shuttle car is an important device in a logistics system of a modern manufacturing enterprise and is an essential important device of a multi-layer shuttle type goods shelf. Multi-deck shuttle to people systems have become more and more popular with customers in recent years, while four-way shuttles have also become the preferred shuttle for many customers.

The existing four-way shuttle car mostly adopts two sets of mechanisms of jacking and reversing to realize the jacking of materials and the reversing of walking wheels, but the operation of jacking and reversing needs one driving mechanism respectively, so that the internal structure is complex, the control is inconvenient, the size is increased, and the use cost is also high.

Disclosure of Invention

The invention aims to solve the technical problem of providing a shuttle vehicle with the functions of jacking and reversing, and effectively overcomes the defects of the prior art.

The technical scheme for solving the technical problems is as follows:

a shuttle car with the functions of jacking and reversing, which comprises a fixed frame, a movable frame, a top plate and a jacking and reversing mechanism, two ends of the fixing frame are respectively rotatably and convexly provided with an X-direction travelling wheel set which can roll and travel towards the two sides of the fixing frame downwards, the top plate is provided with two top plates, and are respectively horizontally arranged above two sides of the fixed frame, the movable frame is arranged in the fixed frame, and can move up and down relative to the fixed frame, two sides of the movable frame are respectively rotatably and convexly provided with a Y-direction travelling wheel group which can roll and travel towards two ends of the movable frame, the jacking and reversing mechanism is arranged on the fixed frame, and are respectively connected with the two top plates and the movable frame in a transmission way, the jacking and reversing mechanisms are used for respectively driving the two top plates to synchronously move up and down, and driving the movable frame to drive the Y-direction travelling wheel set to move up and down in a staggered manner relative to the X-direction travelling wheel set.

On the basis of the technical scheme, the invention can be further improved as follows.

Further, the fixed frame is of a rectangular parallelepiped frame structure, the frames at two ends of the fixed frame are respectively and rotatably provided with the X-direction traveling wheel set protruding downwards, the corresponding movable frame is of a rectangular parallelepiped structure, and the Y-direction traveling wheel sets are respectively positioned outside two sides of the fixed frame.

Furthermore, a plurality of groups of the X-direction travelling wheel sets are arranged at any one end of the fixing frame at intervals, and a plurality of groups of the Y-direction travelling wheel sets are arranged at any one side of the fixing frame at intervals.

Further, the jacking and reversing mechanism comprises a transmission shaft, a driving mechanism and a double-cam transmission assembly, the transmission shaft is horizontally arranged between the middle parts of the two side frames of the fixed frame, the two ends of the transmission shaft respectively extend into the two side frames of the fixed frame and are respectively rotatably connected with the two side frames, the driving mechanism is arranged in the fixed frame and is connected with the transmission shaft for driving the transmission shaft to rotate around the axis of the transmission shaft, the double-cam transmission assembly is provided with two groups and is distributed at the two ends of the transmission shaft, each group of double-cam transmission assembly comprises at least one transmission unit, each transmission unit comprises a main shaft, a jacking cam and a reversing cam, the main shaft is rotatably arranged in the corresponding side frame of the fixed frame and extends towards the two sides of the fixed frame, and the jacking cam and the reversing cam are respectively arranged on the main shaft, the two phase angles are different, the upper part of the jacking cam is provided with a jacking roller which is in rolling contact with the jacking cam, the lower part of the reversing cam is provided with a reversing roller which is in rolling contact with the reversing cam, the jacking roller is arranged at the lower end of the top plate at the corresponding side through a jacking roller seat which is in rotating connection with the jacking roller, the reversing roller is arranged on the movable frame through a reversing roller seat which is in rotating connection with the reversing roller, two ends of the transmission shaft are respectively in transmission connection with the main shaft of the transmission unit at the corresponding side so as to synchronously drive the main shaft to rotate around the axis of the main shaft, a first limiting component which is used for enabling the jacking roller to be in close contact with the corresponding jacking cam is connected between the top plate and the side frame at the corresponding side of the fixed frame, and a second limiting component which is used for enabling the reversing.

Furthermore, each group of the double-cam transmission assemblies comprises two transmission units, and the two transmission units are distributed on two side directions of the corresponding end of the transmission shaft.

Furthermore, both ends of the transmission shaft are coaxially provided with a main chain wheel, the main shaft is provided with an auxiliary chain wheel corresponding to the chain wheel, and chains respectively meshed with the main chain wheel and the auxiliary chain wheel are jointly wound outside the main chain wheel and the auxiliary chain wheel.

Further, the driving mechanism comprises a speed reducer and a driving motor, the speed reducer is mounted on the inner side of any side frame of the fixing frame through a mounting frame, a motor shaft of the driving motor is connected with an input shaft of the speed reducer, an output shaft of the speed reducer is parallel to the transmission shaft, the speed reducer and the transmission shaft are respectively and coaxially provided with corresponding transmission chain wheels, and a transmission chain is commonly surrounded outside the two transmission chain wheels.

Further, the first limiting assemblies are provided with four groups and are respectively arranged at the lower end of each top plate, each first limiting assembly comprises a first guide shaft, a first guide seat and a first elastic piece, the upper end of each first guide shaft is fixedly connected with the lower end of the corresponding top plate, the first guide seats are installed in the corresponding side frames of the fixed frames and correspond to the first guide shafts, the lower ends of the first guide shafts penetrate through the corresponding first guide seats, first limiting blocks are arranged at the lower end portions of the first guide shafts, and the first elastic pieces are connected between the corresponding first guide seats and the corresponding first limiting blocks.

Furthermore, the second limiting assemblies are provided with four groups and are respectively arranged at the two ends of any side of the movable frame and correspond to the positions of the side frames corresponding to the fixed frame, each second limiting assembly comprises a second guide shaft, a second guide seat and a second elastic piece, the lower end of each second guide shaft is fixedly connected with the corresponding position of the upper end of the movable frame, the second guide seats are arranged in the corresponding side frames of the fixed frame and correspond to the positions of the second guide shafts, the upper ends of the second guide shafts penetrate through the corresponding second guide seats, second limiting blocks are arranged at the end parts of the upper ends of the second guide shafts, and the second elastic pieces are connected between the corresponding second guide seats and the second limiting blocks.

The invention has the beneficial effects that: structural design is reasonable, and one set of driving system is used in the switching-over of material jacking and automobile body, can reduce the manufacturing cost of shuttle when jacking and switching-over, and the structure is simpler, and control is easier.

Drawings

Fig. 1 is a schematic structural view of a shuttle car with jacking and reversing functions of the invention;

fig. 2 is a schematic structural view of the shuttle car with the lifting and reversing functions of the invention after one side frame of the fixed frame 1 is opened;

fig. 3 is a schematic structural diagram of a transmission unit in the shuttle car with the functions of jacking and reversing.

In the drawings, the components represented by the respective reference numerals are listed below:

1. a fixing frame; 2. a movable frame; 3. a top plate; 4. a jacking and reversing mechanism; 5. an X-direction travelling wheel set; 6. a Y-direction travelling wheel set; 7. a first limit component; 8. a second limiting component; 41. a drive shaft; 42. a drive mechanism; 43. a main shaft; 44. jacking a cam; 45. a reversing cam; 46. jacking rollers; 47. a reversing roller; 71. a first guide shaft; 72. a first guide seat; 73. a first elastic member; 74. a first stopper; 81. a second guide shaft; 82. a second guide seat; 83. a second elastic member; 84. a second limiting block; 412. a chain; 421. a speed reducer; 422. a drive motor; 423. a conveyor chain; 431. a secondary sprocket; 461. a jacking wheel seat; 471. a reversing wheel seat.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

Example (b): as shown in fig. 1 and 2, the shuttle car with the lifting and reversing function of the embodiment comprises a fixed frame 1, a movable frame 2, a top plate 3 and a lifting and reversing mechanism 4, wherein two ends of the fixed frame 1 are respectively rotatably and convexly provided with an X-direction traveling wheel set 5 which travels in a rolling manner towards two sides of the fixed frame, two top plates 3 are respectively and horizontally arranged above two sides of the fixed frame 1, the movable frame 2 is arranged in the fixed frame 1 and can move up and down relative to the fixed frame 1, two sides of the movable frame 2 are respectively rotatably and convexly provided with a Y-direction traveling wheel set 6 which travels in a rolling manner towards two ends of the movable frame 2, the lifting and reversing mechanism 4 is arranged on the fixed frame 1 and is respectively in transmission connection with the two top plates 3 and the movable frame 2, the lifting and reversing mechanism 4 is used for respectively driving the two top plates 3 to move, and driving the movable frame 2 to drive the Y-direction travelling wheel set 6 to move up and down in a staggered way relative to the X-direction travelling wheel set 5.

In the actual working process, power mechanisms for driving the X-direction travelling wheel set 5 and the Y-direction travelling wheel set 6 to travel are mounted on the fixed frame 1 and the movable frame 2, the jacking and reversing mechanisms 4 can drive the top plates 3 on two sides to move up and down (upward movement and upward lifting are material jacking actions), and can also drive the movable frame 2 to move up and down relative to the fixed frame 1, specifically, the movable frame 2 is driven to move up relative to the fixed frame 1 until the Y-direction travelling wheel set 6 is suspended, in this state, the X-direction travelling wheel set 5 is grounded, and the X-direction travelling of the shuttle car is realized, or the movable frame 2 is driven to move down, so that the fixed frame 1 moves up relative to the movable frame 2 until the X-direction travelling wheel set 5 is suspended, in this state, the Y-direction travelling wheel set 6 is grounded, the Y-direction travelling of the shuttle car is realized, the manufacturing cost of the shuttle car during jacking and reversing can be reduced, the structure is simpler, and the control is easier.

In a preferred embodiment, the fixed frame 1 has a rectangular parallelepiped frame structure, the X-traveling wheel sets 5 protruding downward are rotatably provided on the side frames at both ends, the movable frame 2 has a rectangular parallelepiped structure, and the Y-traveling wheel sets 6 are located outside the fixed frame 1 on both sides.

In this scheme, fixed frame 1 and movable frame 2 adopt conventional cuboid type structure, and the cooperation is compact between the structure, specifically, X is to walking wheel group 5 and install on fixed frame 1 both ends broadside frame, and Y is to walking wheel group 6 and install on the long limit frame of 2 both sides of movable frame.

Specifically, the movable frame 2 actually includes a rectangular bottom plate, the upper portion of the two sides of the corresponding long edge of the bottom plate is respectively provided with a vertical mounting plate along the length direction thereof, the lower portion of the side frame of the two sides of the fixed frame 1 is provided with a displacement notch matched with the mounting plate, the mounting plate is arranged in the notch, the Y-direction walking wheel set 6 is arranged outside the mounting plate through a wheel carrier, more specifically, the upper end edge of the mounting plate is actually the city wall type, and the corresponding displacement notch is the matched city wall type notch.

Preferably, a plurality of sets of the X-direction traveling wheel sets 5 are spaced at any end of the fixed frame 1, a plurality of sets of the Y-direction traveling wheel sets 6 are spaced at any side of the fixed frame 1, specifically, two sets of the X-direction traveling wheel sets 5 are disposed at any end of the fixed frame 1, four sets of the Y-direction traveling wheel sets 6 are disposed at any side of the movable frame 2, and the four sets are distributed at equal intervals, so that stable traveling of the shuttle car can be realized.

As a preferred embodiment, as shown in fig. 2 and 3, the lifting and reversing mechanism 4 includes a transmission shaft 41, a driving mechanism 42 and a double cam transmission assembly, the transmission shaft 41 is horizontally disposed between the middle portions of the two side frames of the fixed frame 1, and both ends of the transmission shaft 41 respectively extend into the two side frames of the fixed frame 1 and are respectively rotatably connected with the two side frames, the driving mechanism 42 is installed in the fixed frame 1 and connected with the transmission shaft 41 for driving the transmission shaft 41 to rotate around its own axis, the double cam transmission assembly is provided in two sets and distributed at both ends of the transmission shaft 41, each set of the double cam transmission assembly includes at least one transmission unit, the transmission unit includes a main shaft 43, a lifting cam 44 and a reversing cam 45, the main shaft 43 is rotatably installed in the corresponding side frame of the fixed frame 1, and extending towards the two sides of the fixed frame 1, the lifting cam 44 and the reversing cam 45 are respectively installed on the main shaft 43, and the phase angles of the two are different, the upper part of the lifting cam 44 is provided with a lifting roller 46 in rolling contact with the lifting cam, the lower part of the reversing cam 45 is provided with a reversing roller 47 in rolling contact with the reversing cam, the lifting roller 46 is installed at the lower end of the top plate 3 at the corresponding side through a lifting roller seat 461 in rotating connection with the lifting roller, the reversing roller 47 is installed on the movable frame 2 through a reversing roller seat 471 in rotating connection with the reversing roller, the two ends of the transmission shaft 41 are respectively in transmission connection with the main shaft 43 of the transmission unit at the corresponding side so as to synchronously drive the main shaft 43 to rotate around the axis thereof, a first limit component 7 for enabling the lifting roller 46 to be in tight contact with the corresponding lifting cam 44 is connected between the top plate 3 and the corresponding side frame of, a second limit component 8 for making the reversing roller 47 and the reversing cam 45 closely contact is connected between the movable frame 2 and the fixed frame 1.

In this embodiment, the principle of the specific reversing and jacking is as follows:

when reversing is needed, the driving mechanism 42 drives the transmission shaft 41 to rotate, the transmission shaft 41 drives all the main shafts 43 to synchronously rotate in the same direction, so that the reversing cam 45 on the main shaft 43 rotates to be horizontal (namely the cam does not face upwards), meanwhile, the jacking cam 44 rotates to face downwards, under the state, the jacking roller 46 tightly contacted with the jacking cam 44 is at a low position, the top plate 3 descends to the low position, the reversing roller 47 tightly contacted with the reversing cam 45 moves downwards, and the movable frame 2 is driven to move downwards relative to the fixed frame 1 until the X-direction travelling wheel set 5 is suspended; on the contrary, the jacking cam 44 rotates to the cam face upwards, in this state, the jacking roller 46 tightly contacted with the jacking cam 44 is in a high position, the top plate 3 rises and is ejected, the reversing cam 45 rotates to be horizontal, and the reversing roller 47 tightly contacted with the reversing cam 45 moves upwards to the Y-direction travelling wheel set 6 to be suspended.

More specifically, the linkage rods of the transmission shaft 41 are all installed in the corresponding side frames of the fixed frame 1 through bearing seats in rotary fit with the linkage rods.

In a preferred embodiment, each set of the double cam transmission assemblies includes two transmission units, and the two transmission units are distributed at two sides of the corresponding end of the transmission shaft 41.

In this embodiment, every group's two cam drive assembly is connected with movable frame 2 through designing two drive unit, can make the reciprocating of movable frame 2 more steady.

In a preferred embodiment, a main sprocket is coaxially provided at both ends of the transmission shaft 41, an auxiliary sprocket 431 corresponding to the main sprocket is provided on the main shaft 43, and chains 412 engaged with the main sprocket and the auxiliary sprocket 431 are commonly wound around the outside thereof.

In this scheme, the cooperation through sprocket and chain realizes that transmission shaft 41 drives main shaft 43 rotatory, specifically, it is rotatory to drive vice sprocket 431 through main sprocket and chain 412 when transmission shaft 41 is rotatory to it is rotatory to drive transmission shaft 41, and then drives jacking cam 44 and reversing cam 45 and rotate respectively to different phase angles, thereby realizes reciprocating respectively of roof 3 and movable frame 2 and operates, and transmission structure is simple, stable.

The two side frames of the fixed frame 1 are respectively provided with a chain 412 on the corresponding side to connect with a matched tensioning mechanism for adjusting the tensioning degree of the chain 412, specifically, the tensioning mechanism comprises two chain wheels, the two chain wheels are respectively installed in the corresponding side frames of the fixed frame 1 and symmetrically distributed on the two sides of the transmission shaft 41 and respectively engaged with the upper parts of the chains 412 on the corresponding sides, so that the upper parts of the chains 412 are bent downwards for tensioning.

Preferably, the driving mechanism 42 includes a speed reducer 421 and a driving motor 422, the speed reducer 421 is mounted inside one of the side frames of the fixed frame 1 by a mounting bracket, a motor shaft of the driving motor 422 is connected to an input shaft of the speed reducer 421, an output shaft of the speed reducer 421 is parallel to the transmission shaft 41, the two transmission sprockets are coaxially provided with each other, and a transmission chain 423 is commonly wound around the two transmission sprockets.

In this scheme, actuating mechanism 42 adopts conventional speed reducer drive structure, can be equipped with the rotational speed of transmission shaft 41 adaptation, realizes jacking and the reasonable transformation of switching-over, and its transmission structure is simple, reasonable, and the operation is stable.

As a preferred embodiment, the first stopper assemblies 7 are provided in four sets and are respectively provided at the lower end of each top plate 3, each first stopper assembly 7 includes a first guide shaft 71, a first guide seat 72 and a first elastic member 73, the upper end of the first guide shaft 71 is fixedly connected to the lower end of the corresponding top plate 3, the first guide seat 72 is installed at a position corresponding to the first guide shaft 71 in the corresponding side frame of the fixed frame 1, the lower end of the first guide shaft 71 passes through the corresponding first guide seat 72, a first stopper 74 is provided at the lower end, and the first elastic member 73 is connected between the corresponding first guide seat 72 and the first stopper 74.

In this embodiment, first elastic component 73 is unanimously in compression state to form the effort downwards all the time to roof 3, this effort can make the inseparable rolling contact between jacking gyro wheel 46 and the jacking cam 44 of being connected with roof 3 lower extreme, the design is very ingenious, ensure to cooperate closely between jacking gyro wheel 46 and the jacking cam 44, can not break away from relatively, in addition, under the cooperation of first guiding axle 71 and first guide holder 72, make roof 3 can only take place the displacement change from top to bottom, further ensure not to take place the phenomenon of sideslip separation between jacking gyro wheel 46 and the jacking cam 44.

The first guide holder 72 is a linear bearing through which the first guide shaft 71 passes and is slidably fitted to each other.

The first elastic member 73 is a spring vertically sleeved outside the lower end of the first guide shaft 71.

As a preferred embodiment, the second position limiting members 8 are provided in four sets and are respectively provided at both ends of any one side of the movable frame 2 at positions corresponding to the side frames of the fixed frame 1, each of the second position limiting members 8 includes a second guide shaft 81, a second guide seat 82 and a second elastic member 83, the lower end of the second guide shaft 81 is fixedly connected to the corresponding position of the upper end of the movable frame 2, the second guide seat 82 is installed at the corresponding position of the second guide shaft 81 in the side frame of the fixed frame 1, the upper end of the second guide shaft 81 passes through the corresponding second guide seat 82, and a second stopper 84 is provided at the upper end, and the second elastic member 83 is connected between the corresponding second guide seat 82 and second stopper 84.

In this embodiment, the second elastic member 83 is in a compressed state consistently, so as to form an acting force that is always upward on the movable frame 2, the acting force can promote the reversing roller 47 connected with the lower end of the movable frame 2 to be in close rolling contact with the reversing cam 45, the design is very ingenious, the reversing roller 47 and the top reversing cam 45 are ensured to be closely matched and not to be separated relatively, in addition, under the matching of the second guide shaft 81 and the second guide seat 82, the movable frame 2 can only be displaced vertically, and the phenomenon of side-sliding separation between the reversing roller 47 and the reversing cam 45 is further ensured not to occur.

The second guide seat 82 is a linear bearing through which the second guide shaft 81 passes and is slidably engaged with each other.

In the embodiment, the chain wheel and the chain in the related transmission structure can be replaced by a combined transmission of a belt pulley and a belt.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.