JPH08676B2 - Forklift back-crest positioning device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forklift backcrest positioning device.

Conventional technology Taking in luggage with a fork in a place with depth,
In order to facilitate the unloading, for example, as shown in Japanese Utility Model Publication No. Sho 49-2367, the fork itself can be moved back and forth by a pantograph mechanism, or the back crest is fixed to the sheath attached to the fork, and the sheath is back-crested. It is known that the forward and backward movements can be adjusted together with.

Problems to be Solved by the Invention Even if it is possible to take in and unload cargo in a place with a depth, if the pallet is shorter than the length of the fork, the tip of the fork is forward of the pallet. Since it projects, the tip of the projecting claw damages the pre-loaded luggage or pallet or causes the load to collapse.
Further, although the movement of the fork or the sheath described above is performed by the hydraulic cylinder, when the loaded bag collides with the back crest due to the bubbles mixed in the hydraulic oil and the rattling of the link mechanism, the back crest moves in the front-back direction. There was a risk of a slight movement and a load collapse. Therefore, according to the present invention, the substantial claw length of the fork can be easily adjusted without changing the fork according to the length of the pallet, and even when the baggage collides with the bagcrest, the front and rear of the bagcrest can be adjusted. (EN) A backrest positioning device for a forklift capable of preventing fine movement in a direction.

Means for solving the problem A pair of guide masts are arranged on a carrier equipped with a fork, and sliders connecting the upper and lower end parts of the upper and lower rear ends are freely slidable up and down. On the other hand, the front ends of the upper links and the lower links are connected to the backrests on the claws of the forks at positions offset below the connection point with the slider to form a parallel link mechanism. A cylinder mechanism is mounted across the mast and the parallel link mechanism so that the parallel link mechanism is extended and contracted to move the backrest forward and backward on the forks of the fork.

Action The parallel link mechanism is expanded and contracted by the expansion and contraction operations of the cylinder mechanism, and the back crest is advanced and retracted on the fork claws for positioning, and the substantial claw length of the fork is adjusted. When the baggage collides with the bagcrest, a component force acts diagonally downward at a right angle to the bupcrest and the lower link at the connecting part of the buccrest to the upper link and the lower link, and presses the buck crest onto the nail to prevent the buccrest from moving slightly. To do.

Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a carriage in which a fork 3 is attached to a finger bar 2, and a front side of the finger bar 2 of the carriage 1 has a pair of U-shaped cross section guide masts whose upper ends are connected by an upper beam 5. 4 are provided. Reference numeral 6 denotes a slider fitted and mounted on these guide masts 4 so as to be slidable up and down. At the upper and lower ends, upper links 7 and lower links 8 are connected to pins 9 and 10, respectively. The left and right upper links 7 and the lower links 8 are connected by reinforcing beams 11 and 12 at their intermediate portions, respectively.
The front end portion of the lower link 8 is connected to the back crest 15 on the claw 3a of the fork 3 by connecting the pins 13 and 14 at a position offset below the connection point with the slider 6 to form the slider 6, the upper link 7, and the lower link. The parallel link mechanism 16 is composed of the back crest 15 and the back crest 15. Reference numeral 17 denotes a cylinder mechanism which is disposed so as to straddle the guide mast 4 and the parallel link mechanism 16. In this embodiment, the cylinder body 17a is connected to a bracket 18 provided at the center of the upper beam 5 of the guide mast 4 by a pin 19 and an operating rod. 17b is connected to the bracket 20 provided at the center of the reinforcing beam 12 of the lower link 8 by the pin 21, and the parallel link mechanism 16 is expanded and contracted by the expansion and contraction operation of the cylinder mechanism 17, so that the buckrest 15 is fixed to the fork of the fork 3. It is made to move forward and backward on 3a.

According to the apparatus of the above embodiment, when the cylinder mechanism 17 is extended and contracted, the slider 6 of the parallel link mechanism 16 slides in the guide mast 4 in the vertical direction, and the parallel link mechanism 16 extends and contracts.
Then, the back crest 15 is moved forward or backward on the claw 3a of the fork 3. As a result, the substantial length of the claw 3a of the fork 3
That is, the length L from the tip of the claw 3a to the backrest 15
Can be arbitrarily adjusted in accordance with the length of the pallet or luggage (in this example, the luggage W is shown) as shown in FIGS. On the other hand, when the baggage W is taken in on the claw 3a, the baggage W collides with the back crest 15 and the back crest 15
When an external force F acts rearwardly on the back crest 15, a component force f ₁ acts diagonally downward at a right angle to the upper clink 7 and the lower clink 8 at the upper clink 7 and the lower clink 8 coupling parts, respectively, and the back crest 15 fluctuates. Comes to press on the nail 3a. Therefore, even if there is rattling at each pin connecting portion of the parallel link mechanism 16 or if air bubbles are mixed in the hydraulic oil of the cylinder mechanism 17 and the oil lock is not perfect, the back crest 15 moves in the front-back direction on the claw 3a. It is possible to prevent the fine movement and to reliably position the buckrest 15.

Here, as shown in FIG. 6, if the rough surface 22 is formed, for example, in a sawtooth shape on the upper surface of the claw 3a of the fork 3, it is possible to more reliably prevent the fine movement of the back crest 15 at the time of a luggage collision.

As described above, according to the present invention, the cylinder mechanism and the parallel link mechanism move the back and forth back and forth on the forks of the fork, and the fork length of the fork is arbitrarily set according to the length of the pallet used. Since it can be adjusted, it is possible to prevent the nail tip from protruding from the front end of the pallet and damaging the pre-loaded luggage or the pallet with the nail tip. Further, since the nail length can be easily adjusted without replacing the fork itself or using a sheath, workability can be remarkably improved. Furthermore, the upper link of the parallel link mechanism, each connecting point of the lower link and the back crest is offset and set below the connecting point of the guide mast with the slider,
When the baggage collides with the loaded baggage, component force acts in the direction of pressing the bottom surface of the backcrest onto the forks of the fork, so that fine movement in the front-back direction of the backcrest is prevented and positioning is ensured. It has a great practical effect that it can be performed.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, FIG. 2 is a front view of the back crest cut in half, and FIG. 3 is II of FIG.
Sectional views taken along line I-III, FIGS. 4 and 5 are schematic side views showing an operating state of the present invention, and FIG. 6 is a schematic side view showing a different example of the present invention. 1 …… Carriage, 3 …… Fork, 3a …… Nail, 4 ……
Guide mast, 6 …… Slider, 7 …… Upper link,
8: lower link, 15: back crest, 16: parallel link mechanism, 17: cylinder mechanism.

Claims (1)

[Claims] 1. A pair of guide masts are arranged on a carrier equipped with a fork, and sliders having upper and lower end portions connected to upper and lower end portions of respective upper and lower link ends are slidably mounted in a vertically slidable manner. On the other hand, the front ends of the upper links and the lower links are connected to the backrests on the forks of the forks at positions offset from the connection point with the slider to form a parallel link mechanism, and parallel to the guide mast. A forklift backcrest positioning device comprising a cylinder mechanism for straddling a link mechanism and extending and retracting the parallel link mechanism to move the backcrest back and forth on the forks of the fork.