GB2023537A - Adjustably Mounting Lift Forks - Google Patents

Abstract

Lift fork apparatus having a fork body (7) the upper end of which is formed with a hook portion (8) for engagement selectively with notches (5a) in a transverse support member (5). An inverted T-shaped latch member (17, 18) is carried by the hook portion (8) above the support member (5) and is urged by a spring (23) into a selected notch (5a) and is removably liftable from the notch by a rotatable handle (20) determining whether the latch engages, or is held clear of, a notch. <IMAGE>

Description

SPECIFICATION Lift Fork Apparatus This apparatus relates to lift fork apparatus for positioning a lift fork body on a support member of the apparatus transversely thereof, usually at the forward portion, the support member having a series of spaced notches therein. An object of the invention is to provide a fork body with means to enter a selected one of the notches so as to prevent displacement of the fork body when a notch is engaged.

According to this invention, lift fork apparatus comprises a support member having spaced notches, a fork body, a hook portion thereon to engage the support member, a latch carried by the hook portion and selectively engageable with one of the notches, means to maintain the latch in engaging position, means to prevent such engagement, the latch comprising an inverted Tshaped member whose vertical element extends upwardly through the hook portion and whose cross-arm element constitutes a part to engage with a notch and to prevent such engagement, and an operating part connected to the vertical element above the hook portion for manipulation of the latch.

The invention will now be described by way of example, with reference to the accompanying drawing in which: Figure 1 is a diagrammatic front elevation of a lift truck, showing the mounting of a support member thereon and forks carried thereby; Figure 2 is a detail side elevation, showing a latch in its latching position; Figure 3 is a section on line 3-3 of Figure 2 looking in the direction of the arrows; Figure 4 is a view similar to Figure 2 but in this instance the latch is in its disengaged position; Figure 5 is a section on line 5-5 of Figure 4 looking in the direction of the arrows; Figure 6 is an elevation of a T-shaped member; Figure 7 is an elevation seen at right angles to that of Figure 6; Figure 8 is a plan of a leaf spring; and Figure 9 is a side edge elevation of the leaf spring.

Referring to Figure 1, a lift truck 1 is supported on wheels 2, driven by way of a drive axle 3 and power means, the latter not being shown. This is a common type of lift truck and has a hydraulic piston and cylinder lift unit 3' connected to a lift frame 4 which in turn supports a transverse support member 5. The unit 3' is arranged to raise and lower the support member 5 and in turn the usual lift forks 6 which are mounted on the support member 5.

The lift forks 6 include the usual body, having an upright section 7 thereof with a hook 8 at the upper end and a tine or lift portion 9 at the lower end, the forks being identical. Thus only the fork shown in Figure 1 at the left hand side will be described in detail.

Referring to Figures 2 to 5, the hook 8 has a generally U-shaped portion 10 which includes a downwardly extending short leg 11 and a longer leg 1 2 with a transverse connection 1 3 which extends across the fork and, see Figures 3 and 5, is of substantial transverse extent but is centrally with a recess or cavity 1 4.

Substantially centrally of the hook 8 is a vertical round hole 1 5 which receives an inverted T-shaped member 1 6 having its cross-arm 1 7 connected to a round vertical element 1 8. The cross-arm 1 7 constitutes a latch, which is engageable in a desired one of notches 5a in the support member 5, to prevent lateral movement of a lift fork 6 on the support member 5.

At the upper end of the vertical element 1 8 is a transverse opening 1 9 (Figures 6 and 7) to receive a handle 20, which is a safety pin arrangement including a lower member 21 and an inverted U-shaped member 22, connected thereto; a hook section 24 at one end engages the part 21.

The member 21 extends through the opening 1 9 and by grasping the U-shaped member 22 the T-shaped member 6 may be raised or lowered.

The recess or cavity 14-receives a flat leaf spring 23, so that when the leaf spring is bent to the shape shown in Figure 5, it is fully received within the recess or cavity 14, with the cross-arm of the T-shaped member 1 6 causing the spring to be thus bent, and at the same time permitting the member 1 6 to be raised out of one of the notches 5a of the support member 5, Figure 1.

When the T-shaped member 16 is in the position seen in Figure 3, it can then move downwardly under the action of the spring 23, so that it enters a notch 5a so as to prevent transverse displacement of the fork on the support member 5.

By the same token, raising the handle 20 will cause the cross-arm 1 7 to be withdrawn from a notch 5a, and in order to maintain the cross-arm 1 7 out of engagement with the notch, rotation of the handle 20 will cause it to extend in the position shown in Figure 5 and at the same time cause the cross-arm 1 7 to bridge the notch 5a.

It will be understood that certain limits of movement may be effected to cause the action just described. When it is desired to have the cross-arm 1 7 in notch-engaging position, rotation of the handle 20 may be resorted to, and since there is a recess 25 extending across the hook 8, the handle may drop into that recess, Figures 2 and 3, and thus lock the latch member 16 in position with the cross-arm 1 7 in notch-engaging position.

To remove the latch, the hook section 24 may be removed from the lower member 21 of the handle 20, so that the lower member 21 may then be drawn through the hole 19, to permit the vertical element 1 8 to be removed. It will thus be seen that the handle 20 has a "safety pin" kind of action.

Assembly of the latch is similarly carried out.

The leaf spring 23 has an opening 23a through which the vertical element 18 can be introduced.

Thus operation of the latch includes lifting and rotating, to maintain the latch in disconnected or upraised position out of engagement with a notch 5a, so that the fork with which it is associated may be moved transversely on the support member 5.

Claims (6)

Claims

1. Lift fork apparatus comprising a support member having spaced notches, a fork body, a hook portion thereon to engage the support member, a latch carried by the hook portion and selectively engageable with one of the notches, means to maintain the latch in engaging position, means to prevent such engagement, the latch comprising an inverted T-shaped member whose vertical element extends upwardly through the hook portion and whose cross-arm element constitutes a part to engage with a notch and to prevent such engagement, and an operating part connected to the vertical element above the hook portion for manipulation of the latch.

2. Apparatus according to claim 1 wherein the support member is elongate and extends transversely of the apparatus.

3. Apparatus according to claim 1 or claim 2 wherein the hook portion is at the upper end of the fork body.

4. Apparatus according to any preceding claim wherein the latch includes resilient means and engages the T-shaped member to maintain the same in the notch-engaging position and the operating part is arranged to facilitate lifting and rotating action of the T-shaped member, the means to prevent engagement of the T-shaped member being operative upon rotation of such means for the preventive action.

5. Apparatus according to claim 4 wherein the resilient means comprises a flat spring, the hook portion having a recess to locate the spring, the recess being so formed as to cause bending of the spring thereinto when the T-shaped member is raised by the operating part, and limited rotation of the operating part thereafter moving the operating part into a position to maintain the Tshaped member out of notch-engaging position.

6. Lift fork apparatus constructed and arranged substantially as herein described with reference to the drawing.