Fork Adjuster for a Forklift Truck, Forklift Truck Provided Therewith and Method for Adjusting Forks

Abstract

The invention relates to a fork adjuster, forklift truck provided therewith and method for adjusting forks. The fork adjuster according to the invention comprises: a frame provided with coupling means configured to operatively couple the fork adjuster to the forklift truck; an adjusting mechanism arranged in or on the frame and configured to adjust the forks; a drive mechanism which can be connected operatively to the adjusting mechanism for driving the adjusting mechanism, wherein the drive mechanism is provided with contact means such that the adjusting mechanism is driveable by contact of the contact means with a ground surface.

Claims

1. A fork adjuster for a forklift truck, comprising: a frame provided with coupling means configured to operatively couple the fork adjuster to the forklift truck; an adjusting mechanism arranged in or on the frame and configured to adjust the forks; a drive mechanism which can be connected operatively to the adjusting mechanism for driving the adjusting mechanism, wherein the drive mechanism is provided with contact means such that the adjusting mechanism is driveable by contact of the contact means with a ground surface,

2. The fork adjuster according to claim 1, wherein the contact means comprise one or more wheels or rollers.

3. The fork adjuster according to claim 1, wherein the adjusting mechanism is provided with at least one spindle.

4. The fork adjuster according to claim 3, wherein the spindle is provided with an opposite screw thread for adjacent forks.

5. The fork adjuster according to claim 3, or wherein the adjusting mechanism is provided with an additional guide.

6. The fork adjuster according to claim 5, wherein the additional guide is a spindle.

7. The fork adjuster according to claim 1, further provided with a transmission ratio between fork displacement and forklift truck displacement, wherein the transmission ratio is greater than 1.

8. The fork adjuster according to claim 1, further comprising a slip coupling between the contact means and the forks.

9. The fork adjuster according to claim 1, further comprising an activator configured to activate the drive mechanism.

10. The fork adjuster according to claim 9, wherein the activator comprises a coupling with a tilting system configured to tilt the forks backwards.

11. The fork adjuster according to claim 9, further comprising a gear transmission for forming a non-direct transmission between the contact means and the adjusting mechanism.

12. The fork adjuster according to claim 9, wherein the activator comprises a contact element which can be operated by a user.

13. The fork adjuster according to claim 9, wherein the activator comprises a remote control.

14. The fork adjuster according to claim 1, further comprising a fork position sensor for measuring the position of at least one of the forks.

15. The fork adjuster according to claim 1, wherein the forks comprise extendable forks.

16. A forklift truck provided with a fork adjuster comprising: a frame provided with coupling means configured to operatively couple the fork adjuster to the forklift truck; an adjusting mechanism arranged in or on the frame and configured to adjust the forks: a drive mechanism which can be connected operatively to the adjusting mechanism for driving the adjusting mechanism, wherein the drive mechanism is provided with contact means such that the adjusting mechanism is driveable by contact of the contact means with a ground surface.

17. A method for adjusting forks of a forklift truck, comprising of: providing a fork adjuster for a forklift truck, with the forklift truck comprising: a frame provided with coupling means configured to operatively couple the fork adjuster to the forklift truck; an adjusting mechanism arranged in or on the frame and configured to adjust the forks; and a drive mechanism which can be connected operatively to the adjusting mechanism for driving the adjusting mechanism, wherein the drive mechanism is provided with contact means such that the adjusting mechanism is driveable by contact of the contact means with a ground surface; and adjusting the forks.

18. The method according to claim 17, further providing a slip coupling between the contact means and the forks.

19. The forklift truck according to claim 16, further comprising a slip coupling between the contact means and the forks.

20. The forklift truck according to claim 19, wherein the contact means comprise one or more wheels or rollers and wherein the adjusting mechanism is provided with at least one spindle.

Description

[0041] Further advantages, features and details of the invention are elucidated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying drawings, in which:

[0042] FIG. 1 shows a view of a forklift truck provided with a fork adjuster according to the invention;

[0043] FIG. 2 shows a view of an AGV provided with a fork adjuster according to the invention, wherein the forks are embodied as outward slidable (extending) forks;

[0044] FIG. 3A-B show views of a fork adjuster according to the invention with additional transmission;

[0045] FIG. 4 shows a forklift truck provided with a push-pull system; and

[0046] FIG. 5A-B shows the forklift truck of FIG. 1, wherein the fork adjuster is embodied as a sideshift mechanism (FIG. 5A) and fork adjustment (FIG. 5B).

[0047] Forklift truck 2 (FIG. 1) is provided with fork adjuster 4. In the shown embodiment fork adjuster 4 is provided with frame 6 on which two forks 8, 10 can be arranged. Frame 6 can be connected via coupling 11 (shown schematically) to forklift truck 2. Frame 6 is further provided with a first spindle 12 and second shaft/spindle 14 which are arranged rotatably in frame 6 in suspension or bearing 16. In the shown embodiment spindles 12, 14 are mutually connected via drive 18, embodied as a belt in the shown embodiment.

[0048] In the shown embodiment turns of one or more spindles 12, 14 are measured using schematically shown fork position sensor 20 (FIG. 1), whereby the position of forks 8, 10 is known. Using bushes 24, forks 8, 10 are movable along shafts/spindles 12, 14, wherein these are in a preferred embodiment provided with first thread 26 and second, opposite thread 28. Running wheel 30 is operatively connected as contact means to spindle 12. Running wheel 30 can be placed on ground surface G, whereby spindle 12 will rotate. In the shown embodiment the rotation of spindle 12 will be transmitted via transmission 18 to spindle/shaft 14. This provides for movement of bushes 24 and thereby adjustment of forks 8, 10, whereby in this shown embodiment the mutual distance of forks 8, 10 is reduced or is conversely increased.

[0049] In the shown embodiment forklift truck 2 is provided with cab 32 (FIG. 1) with seat 34 and steering wheel 36. Tilting system 38 makes it possible to incline mast 40 forward and rearward and thereby for instance bring running wheel 30 into contact with ground surface G. In additional or alternative manner it is possible to provide operating handle 42 with which running wheel 30 is operatively connected via a mechanical connection (for instance a gear connection) to spindle 12. Alternatively or additionally, a (Bluetooth) signal 46 with which activation is carried out can be generated using transmitter 44.

[0050] In an alternative embodiment AGV 102 (FIG. 2) is provided with fork adjuster 104. In this embodiment forks 108, 110 are embodied as so-called extending forks which are outward slidable in direction A. It will be apparent that forks 8, 10 and extending forks 108, 110 are interchangeable and can both be used on forklift truck 2 and/or AGV 102.

[0051] Fork adjuster 204 (FIG. 3A-B) is provided with running wheel 230 which runs over ground surface G. In the shown embodiment running wheel 230 is arranged on arm 232 which is provided using shaft 234 on frame 206 of fork adjuster 204. Arm 232 is provided on the other side with support wheel 236.

[0052] In the normal position, with a fork adjuster 204 moved in downward direction B, running wheel 230 will co-rotate when forks 208, 210 move over ground surface G. In the shown uncoupled embodiment (FIG. 3A) running wheel 230 is in such a position not operatively connected to spindle 212 because toothed wheels 238, 240 are not in engagement. In this shown embodiment optional spring mechanism 242 provides for a mutual distance between toothed wheels 238, 240.

[0053] By moving forks 208, 210 from the “straight” position in direction C to a position in a tilting position (FIG. 3B) toothed wheel 238 will be brought into engagement with toothed wheel 240 counter to the spring action of spring 242. Running wheel 230 is hereby connected operatively to spindle 212 arranged in frame 206. The adjustment of forks 208, 210 can hereby be realized in effective manner It will be apparent that in this shown embodiment the forward movement or rearward movement in direction D of running wheel 230 realizes an opposite adjustment of forks 208, 210. If desired, it is also possible to dispense with spring 242.

[0054] In an alternative embodiment forklift truck 302 (FIG. 4) is provided with push-pull system 303 with an adjustment allowed by adjuster 304. Provided in this shown embodiment is a first spindle shaft 312 and a second slide shaft 313. It will be apparent that such a slide shaft 313 can also be applied in other embodiments, such as forklift truck 2 and/or AGV 102.

[0055] A further alternative embodiment shows forklift truck 402 provided with adjusting mechanism 404 (FIG. 5A), wherein thread on spindles 412, 414 is the same on the left-hand and right-hand side, whereby a sideshift mechanism is obtained. It will be apparent that such a sideshift mechanism can also be realized with other shown embodiments for the forklift truck 2, 102, 302.

[0056] In the case that forklift truck 502 (FIG. 5B) is provided with fork adjuster 504 the mutual distance d between forks 508, 510 can be adjusted when driving toward a pallet. Using for instance tilting system 38 (FIG. 1) drive wheel 30, 230 can be brought into contact with the ground surface G such that spindle 12, 212 is driven hereby, whereby forks 8, 10, 108, 110, 208, 210, 508, 510 are adjusted. It is possible here to have forks move toward each other when driving forward or move apart when moving rearward, or conversely vice versa. It is also possible to provide the movement as sideshift movement (FIG. 5A).

[0057] The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged.