JPS6245160B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a lifting and lowering system for vertically raising and lowering a load supported by a load receiving device to change the height of the load to a height convenient for transferring the load to and from other devices. The present invention relates to a cargo receiving device.

More specifically, as shown in FIGS. 1 to 4, a movable platform 2 provided on a base 1 that is movable in the front-rear direction and a rear end of a load receiving device 3 are connected front and rear to form a parallel quadruple link. A third link 6 is connected by a pair of links 4 and 5, and one of the links 4 and 5, for example, link 4 and the base 1, is used to move the load receiving device 3 vertically in parallel. This relates to a lifting/lowering load receiving device which is connected to each other.

According to such an elevating load receiving device, as shown in FIG. It can be lowered to an extremely low position so that it overlaps the top. However, on the other hand, when moving the movable platform 2 backward as shown by the arrow 7 to raise the load receiving device 3, the pivot shafts 4 at both ends of the link 4
Since the line connecting a and 4b is almost horizontal, an extremely large force is required at the beginning of the movement of the movable platform 2, that is, at the beginning of the upward movement of the load receiving device 3.

The present invention aims to solve the above-mentioned problems, and one embodiment thereof will be described below based on the attached illustrative drawings.

The movable platform 2 has a pair of left and right side frames, each of which has wheels 9 pivotally supported at both front and rear ends thereof, which fit into front and rear guide rails 8 formed on both sides of the base 1, and which are connected by a horizontal frame 10 at the rear end. It is made up of The load receiving device 3 is constructed by connecting the rear ends of a pair of right and left load receiving angle members 11 by a connecting member 12, and a pair of left and right link shaft support plates 13 are attached to the center of the connecting member 12. Link 4,5
are pivotally supported by a pair of left and right pivot shafts 4a, 4b and 5a, 5b on both side frames of the movable base 2 and the pair of left and right link shaft support plates 13, respectively.
a, 5a are located concentrically with the wheel 9.

A pair of left and right third links 6 are also provided corresponding to the left and right pairs of links 4, and the length between the pivot shafts 6a and 6b at both ends is equal to the length between the pivot shafts 4a and 6b of the links 4, respectively.
It is exactly half the length between the pivot shafts 4a and 4b, and is pivotally supported at the center position between the pivot shafts 4a and 4b.

Reference numeral 14 denotes a moving body that moves forward and backward on the base 1, and at its rear end there is a pair of left and right wheels 15 that roll on the base 1, and a pair of left and right cam rollers 16 that have a smaller diameter than the wheels 15. A pusher 17 for pressing the horizontal frame 10 rearward is attached to the front end of the movable base 2 extending forward beyond the horizontal frame 10. Reference numeral 18 denotes a cam that projects inside the third link 6, and is configured such that its lower cam surface 18a can come into contact with the cam roller 16. This cam surface 18a
As shown in FIG. 1, when the load receiving device 3 is at the lower limit position and the third link 6 is in a substantially horizontal forward tilted position, the position is from the front end position a where the cam roller 16 is fitted to the rear end position. It slopes backward and downward across b. Reference numeral 19 denotes a drive means for the movable body 14, which includes a horizontal cylinder unit 21 housed in a machine frame 20 connected in a T-shape at the rear end of the base 1, the tip of its piston rod, and the rear end of the movable body 14. and a chain 23 suspended through a guide ring 22 between.

To explain how to use it and how it works, as shown in FIG. Located at the front end position a on the cam surface 18a of the link 6, the pusher 1
7 is located at a position away from the horizontal frame 10 of the movable base 2 in front.

In such a state, the cylinder unit 21
When the moving body 2 is moved backward as indicated by the arrow 7 via the chain 23, the cam roller 16
This causes the third link 6 to be pushed upward around the pivot shaft 6a via the cam surface 18a of the third link 6 with a wedge effect. As a result, the front and rear pairs of links 4 and 5 are pulled up by the third link 6, and while the movable base 2 is dragged backward as indicated by arrow 7, the links 4 and 5 are moved so that the positions of the pivot shafts 4b and 5b are vertical. This will cause you to stand up and move upward. Therefore, the load receiving device 3 begins to move vertically in parallel upward movement.

As shown in FIG. 2, when the cam roller 16 reaches the rear end position b of the cam surface 18a, and in the example shown, when the links 4 to 6 stand up to approximately 25 degrees, The pusher 17 that was moving together with the cam roller 16 comes into contact with the horizontal frame 10 on the movable base 2. Therefore, from this point on, as the movable body 14 moves backward, the pusher 17 pushes the movable base 2 directly in the direction of the arrow 7, and the cam roller 16 moves the cam 1 on the third link 6.
8 and moves rearward. As a result of the movable base 2 being pulled rearward in this way, the pair of front and rear links 4 and 5 are moved to the pivot shaft 4 by the third link 6.
The standing movement is performed so that the positions b and 5b rise vertically, and the load receiving device 3 is raised vertically and parallelly to the upper limit position as shown in FIG.

As shown in FIG. 3, when the piston rod that is pulling the chain 23 is moved backward by the cylinder unit 21 from the state where the load receiving device 3 is at the upper limit position, the movable platform is moved by the force of gravity acting on the load receiving device 3, etc. 2 moves forward while pulling the movable body 14 via the horizontal frame 10 and pusher 17, and the load receiving device 3 moves vertically and parallelly downward. Links 4-6
When the cam surface 18a of the third link 6 falls down to approximately 25 degrees, the rear end of the cam surface 18a of the third link 6 comes into contact with the cam roller 16, and from then on, this cam surface 18a presses the movable body 14 forward via the cam roller 16. While being moved, the links 4 to 6 are moved by gravity to the fully collapsed position shown in FIG. 1, and the load receiving device 3 reaches the lowering limit position.

Note that the driving means 19 of the movable body 14 may be capable of forcibly moving the movable body 14 in either direction. Further, a spring for forcibly moving the movable body 2 forward and a spring urging at least one of the links 4 to 6 in a direction to collapse may be used in combination. Furthermore, instead of directly connecting the chain 23 to the movable body 14, the chain 23 is hung on a guide wheel (corresponding to a movable pulley) that is pivotally supported on the movable body 14, and the free end of the chain 23 is latched to the base 1. By doing,
The driving force can be further reduced.

According to the lifting load receiving device of the present invention that can be implemented as described above, the first half of the process of lifting the load receiving device from the lowering limit position is moved rearward using the cam surface of the third link in the forward tilted position. The load receiver can be raised by pushing up the third link in a wedge-like manner using the cam roller, so the load receiver can be lowered to an extremely low position where each link is laid down in a nearly horizontal position, as shown in Figure 1. Even if the load receiving device is raised, only a very small driving force is required at the initial stage of raising the load receiving device. Moreover, in the latter half of the stroke when the link is in a somewhat erect state, the movable base is directly pressed and moved by the pusher, so in both the first half and the second half of the stroke,
The rearward movement force of a moving body equipped with a cam roller and a pusher is efficiently converted into an increased force and transmitted to the load receiving device, and this load receiving device can be smoothly moved upward with a small force. Further, according to the present invention, since it is sufficient to linearly move one moving body equipped with a cam roller and a pusher back and forth, the entire structure including the driving means is simple and can be implemented at low cost.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIGS.
The figures are longitudinal sectional side views in different states, and FIG. 4 is a plan view in the state shown in FIG. 1. DESCRIPTION OF SYMBOLS 1... Base, 2... Front-back movable platform, 3... Load receiver, 4, 5... Front and rear pair of links, 6... Third link, 8... Guide rail, 9, 15... Wheels, DESCRIPTION OF SYMBOLS 10...Movable horizontal frame, 14...Back and forth moving body, 16...Cam roller, 17...Pusher, 18...Cam, 18a...Cam surface, 19...
Drive means, 21... Cylinder unit, 23...
...Chien.

Claims (1)

[Claims] 1. A movable platform provided on the base that is movable in the longitudinal direction and the rear end of the load receiving device are connected by a pair of front and rear links forming a four-parallel link, and one link of the pair of front and rear links and the The load receiving device is connected to the base by a third link for vertically parallel vertical movement of the load receiving device, and a movable body provided on the base that is movable in the front and back direction has the third link by moving rearward.
A cam roller that acts on a cam surface connected to the link to move the third link in the forward tilted position (the load receiver is in the lowering limit position) up to a predetermined angle, and A lifting load receiving device comprising a pusher for pushing a movable platform rearward and a drive means for moving the movable body back and forth.