JPH0712919B2 - Forklift side shift device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side shift device for a forklift for laterally moving left and right forks with a constant interval.

(Prior Art) A conventional side shift device for a forklift is usually configured such that a fork is slidably attached to a finger bar fixed to the front surface of a lift bracket via a shifter and moved laterally by a shift cylinder. An example of such a side shift device is, for example, Japanese Utility Model Laid-Open No. 60-43698 (hereinafter referred to as the first publication).
Alternatively, JP-A-62-276000 (hereinafter referred to as the second publication) can be mentioned.

In the former first publication, a fork bar for mooring and supporting the fork is arranged on the front surface of the finger bar, and the fork bar is attached to the finger bar via a pair of upper and lower shifters so as to be movable laterally. The left and right forks are laterally moved together with the fork bar with a shift cylinder by a shift cylinder to perform a side shift operation. The distance between the left and right forks is adjusted by changing the mooring position of the forks with respect to the fork bar.

In the latter second publication, the shifter is formed in a gate shape that fits over the upper part of the finger bar so as to straddle the front and rear, and the upper and lower surfaces of the finger bar are arranged in the gate-shaped space of the shifter. It has a pair of upper and lower rollers for rolling, and the left and right forks are moored and supported by the shifter, and the left and right forks are laterally moved together with the shifter at a fixed interval by the shift cylinder to perform the side shift. I am trying to do it. The fork spacing is adjusted by changing the mooring position with respect to the shifter.

(Problems to be Solved by the Invention) However, the conventional device described above has the following problems.

That is, in the former case of the first publication, since the fork bar is arranged on the front surface of the finger bar via the shifter, the front-rear distance from the front surface of the mast to the fork is large, and the total weight of the side shift device is large. Therefore, there is a problem that the allowable load decreases.

Also, in the latter case of the second publication, although the shifter is fitted on the finger bar to reduce the distance in the front-rear direction from the front of the mast to the fork, the front of the finger bar has the front of the shifter. There is no change in the position of the portion, and there is substantially no difference as compared with that of the first publication.

In any case, in the conventional side shift device, the existence of the shifter causes a problem of reducing the allowable load. However, in adjusting the fork interval according to the lateral width of the cargo to be handled. The shifter is an indispensable member.

Therefore, in view of the above problems, it is an object of the present invention to provide a side shift device which has a structure in which a shifter is abolished and which can perform side shift of a fork and interval adjustment.

(Means for Solving the Problems) The present invention is configured as follows to solve the above problems.

Left and right forks are slidably moored directly on the upper and lower finger bars fixed to the front surface of the lift bracket, and female screw members are provided on the rear surfaces of the respective forks.

Further, between the upper and lower finger bars, a screw shaft having a left-hand thread and a right-hand thread is horizontally arranged with the center as a boundary, and both ends of the screw shaft are vertically oriented to the left and right end portions of the finger bar, respectively. It is supported movably and rotatably in the axial direction with respect to the left and right plates that are fixed to each other, and the female screw members on the rear surface of the fork are screwed into the respective screws of the screw shaft.

Further, a joint member that is rotatable about the axis of the screw shaft and fixed in the axial direction is provided at the center of the screw shaft, and the joint member has a shift cylinder whose one end is connected to the plate or the finger bar. Is connected to the other end.

(Operation) The side shift device of the present invention configured as described above,
When the shift cylinder expands and contracts, the screw shaft is guided by the left and right plates to move in the axial direction, so that the left and right forks also move laterally together with the screw shaft while maintaining a constant interval, so-called side shift operation is performed. Also, when the screw shaft is rotated at a fixed position, the left and right forks approach each other or are separated from each other, and the distance between them is adjusted.

(Example) Hereinafter, the Example of this invention is concretely described based on drawing.

As shown in FIGS. 1 and 2, finger bars 3 are fixed to the front surface of a lift bracket 2, which is an elevating member that is moved up and down along a mast 1 of a forklift truck, at predetermined vertical intervals. Further, vertically long plates 4 are fixed to the side surfaces of the left and right ends of the upper and lower finger bars 3 by bolts 5 (which may be welded).
Lateral shaft holes 4a are concentrically formed at positions relatively close to the upper part of.

As shown in FIG. 1, a screw shaft 6 is horizontally arranged between the upper and lower finger bars 3. This screw shaft 6 has a small-diameter shaft portion 6a at the center thereof.
With a right screw 6b on one side, a left screw 6c on the other side, a shaft portion 6d of a corresponding length on each of the left and right end portions, and a square shaft portion 6e on at least one end portion. Each of them has a structure, and its entire length is considerably longer than the finger bar 3.

In the screw shaft 6 constructed as described above, the left and right shaft portions 6d are movably and rotatably supported in the shaft hole 4a of the plate 4 via the bush 7 as shown in FIG. There is. The left and right shaft portions 6d are projected outward from the plate 4 by a predetermined amount, and this projection amount L corresponds to the side shift amount, which is normally set to about 10 cm. In correspondence with this, the ends of the right-hand screw 6b and the left-hand screw 6c end inside from the inner surface of the plate 4 by an amount corresponding to the protrusion amount L.

Further, as shown in FIG. 1, a shift cylinder 8 is provided below the screw shaft 6 between the finger bars 3.
Are arranged in parallel. The shift cylinder 8 has one end rotatably connected to a bracket 9 fixed to one plate 4 through a pin 10, and also has a piston rod 8a.
Has a metal on the small-diameter shaft portion 6a of the screw shaft 6.
It is connected via a joint member 11 which is rotatably attached.

As shown in FIGS. 4 and 5, the joint member 11 and the metal 12 both have a two-divided structure in the vertical direction, and are joined by the bolts 13 while being fitted to the small diameter shaft portion 6a. It is fixed in the axial direction. A bracket 11a is fixed to the lower part of the joint member 11, and the bracket 11a is rotatably connected to the tip of the piston rod 8a by a pin 14.

In addition, as shown in FIG.
The forks 15 of the book are moored and supported by a pair of upper and lower hooks 16 so as to be laterally movable, and the female screw member 17 fixed to the back surface of the fork 15 is attached to the right screw 6b and the left screw 6c of the screw shaft 6. It is screwed. If the front end of the lift bracket 2 interferes with the female screw member 17, the shift cylinder 8 or the joint member 11, a recess for avoiding interference is formed.

The side shift device of the present embodiment is configured as described above. Therefore, when the shift cylinder 8 is expanded and contracted, the screw shaft 6 connected to the shift cylinder 8 via the joint member 11 is guided to the left and right plates 4. Then, since it moves laterally as shown by the arrow in FIG. 1, the fork 15 in which the female screw member 17 is screwed into the screws 6b and 6c of the screw shaft 6 moves integrally with the screw shaft 6. That is, the left and right forks 15 move to the right or left while being guided by the finger bar 3 while maintaining a constant interval, and a so-called side shift operation is performed.

On the other hand, when adjusting the left and right fork intervals so as to correspond to the width of the load to be loaded or the width of the fork insertion port of the pallet, the handle 18 is attached to the angular shaft portion 6e of the screw shaft 6 and the handle 18 is attached as shown in FIG. When the screw is rotated clockwise or counterclockwise as indicated by the arrow, the female screw member 17 screwed to the right screw 6b and the female screw member 17 screwed to the left screw 6c move in opposite directions. . That is, the left and right forks 15 approach or are separated from each other, and the distance between them is adjusted.

(Effects of the Invention) As described in detail above, the side shift device of the present invention has a structure that does not have a shifter, which is indispensable for the conventional device, but side shift operation for laterally moving the left and right forks at a constant interval. And a space adjusting operation for moving the left and right forks toward or away from each other. Since the shifter and the fork bar are omitted, the distance from the front of the mast to the fork is greatly shortened compared to the conventional device, and the weight of the side shift device itself is reduced, which increases the allowable load of the vehicle. can do.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is an overall perspective view of a side shift device, Fig. 2 is a side sectional view of the same, Fig. 3 is a sectional view showing a supporting portion of a screw shaft, and Fig. 4 is a joint. FIG. 5 is a sectional view showing the mounting structure of the members, and FIG.
It is a -V line sectional view. 2 ... Lift bracket, 3 ... Finger bar 4 ... Plate, 6 ... Screw shaft 6b ... Right screw, 6c ... Left screw 8 ... Shift cylinder, 11 ... Joint member 15 ... Fork, 17 ... Female screw member

Claims (1)

[Claims] 1. Left and right forks are slidably moored to upper and lower finger bars fixed to the front surface of a lift bracket, and female screw members are provided on the back surfaces of the respective forks, and between the upper and lower finger bars. Is a horizontal screw shaft with left and right threads formed at the center, and both ends of this screw shaft are attached to the left and right plates vertically attached to the left and right ends of the finger bar. Supported so as to be movable in the axial direction and rotatably, and further, each screw of the screw shaft is screwed with the female screw member on the rear face of each fork, respectively,
A joint member that is rotatable about the axis of the screw shaft and fixed in the axial direction is provided at the center of the screw shaft, and the joint member is connected to the plate or finger bar of a shift cylinder. A side shift device for a forklift that is connected to the other end.