Method for operating an industrial truck with an operating element

Abstract

A method for operating an industrial truck with an operating element comprising at least one operating for a vehicle function, an unlocking apparatus for the vehicle function, and a resetting apparatus configured to interact with the at least one operating lever generating a resetting force depending on a deflection of the least one operating lever. Upon an actuation of the operating lever without previously unlocking the operating lever, the resetting force acting on the at least one operating lever is changed in order to report an unsuccessful unlocking procedure.

Claims

1. A method for operating an industrial truck with an operating element comprising at least one operating for a vehicle function, an unlocking apparatus for the vehicle function, and a resetting apparatus configured to interact with the at least one operating lever, the method comprising: generating a resetting force depending on a deflection of the least one operating lever, wherein the resetting force acting on the at least one operating lever is changed in order to report an unsuccessful unlocking procedure upon activation of the operating lever without previously unlocking the operating lever.

2. The method according to claim 1, wherein the industrial truck further comprises a fork adjuster and the unlocking apparatus further comprises a load sensor, and wherein actuation of the fork adjuster is locked when the load sensor detects a load.

3. The method according to claim 1, wherein the unlocking apparatus is configured to actuate independent of the operating lever.

4. The method according to claim 1, wherein the resetting apparatus is configured to block a movement of the at least one operating lever until the unlocking apparatus has been actuated.

5. The method according to claim 1, wherein the unlocking apparatus is configured to be actuated before an attachment can be actuated.

6. The method according to claim 5, wherein the attachment is one of a clamping attachment or rotating attachment.

7. The method according to claim 1, wherein the resetting apparatus is configured to increase the resetting force when the at least one operating lever is moved without the unlocking apparatus being actuated beforehand.

8. The method according to claim 7, wherein the resetting apparatus is configured to increase the resetting force in a pulsating manner when the at least one operating lever is moved without the unlocking apparatus being actuated beforehand.

9. An operating element for an industrial truck comprising: at least one operating lever configured for a vehicle function; an unlocking apparatus configured for the vehicle function; and a resetting apparatus configured to interact with the at least one operating lever to indicate a resetting force depending on a deflection of the least one operating lever, wherein the resetting apparatus is configured to indicate the resetting force to the at least one operating lever before an actuation of the unlocking apparatus to provide feedback that an unlocking procedure has not occurred.

10. The operating element according to claim 9, further comprising: a fork adjuster comprising an actuating apparatus; and a load sensor disposed on the unlocking apparatus, wherein the actuating apparatus for the fork adjuster is locked when the load sensor detects a load.

11. The operating element according to claim 9, wherein the unlocking apparatus has an unlocking means configured to be actuated independent of the operating lever.

12. The operating element according to claim 11, wherein the unlocking means comprises at least one of a button, a switch, or a slide.

13. The operating element according to claim 11, wherein the unlocking means comprises a component configured to be actuated.

14. The operating element according to claim 9, further comprising at least one of a clamping or rotating attachment configured to be actuated after a locking apparatus is actuated.

15. The operating element according to claim 9, wherein the resetting apparatus is configured to block a movement of the at least one operating lever until the unlocking apparatus has been actuated.

16. The operating element according to claim 9, wherein the resetting apparatus is configured to increase the resetting force when the at least one operating lever is moved without the unlocking apparatus being actuated beforehand.

17. The operating element according to claim 9, wherein the resetting apparatus is configured to change the resetting force in a pulsating manner when the at least one operating lever is moved without the unlocking apparatus being actuated beforehand.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A preferred embodiment of the invention is explained in greater detail below. In the following:

(2) FIG. 1 illustrates a schematic view of an embodiment of an industrial truck;

(3) FIG. 2 illustrates an operating lever and an unlocking switch of an embodiment of an operating element of the industrial truck;

(4) FIG. 3 illustrates an embodiment of a clamping attachment for the industrial truck;

(5) FIG. 4 illustrates an embodiment of a load carriage for the industrial truck;

(6) FIG. 5 illustrates an embodiment of a fork adjuster attachment for the industrial truck; and

(7) FIG. 6 illustrates a curve demonstrating the relationship between the resetting force and the deflection of the operating lever.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a counterbalance truck or an industrial truck 10 which has a drive part 12 and a load part 14. The drive part 12 possesses two front wheels 16 and one or two rear wheels 18 depending on the design of the chassis. A lifting mast 22 is coupled to the drive part 12 at an articulation point 20 and is configured to pivot about the articulation point 20. The lifting mast 22 can be tilted forward or backward by means of a tilt cylinder 24. In this case, the lifting mast 22 comprises a forked load carrying means 26 on which a load 28 is disposed. In principle, other load carrying means can also be arranged on the lifting mast 22. It is therefore possible to provide a fork adjuster that permits varying the distance between the forks (FIG. 5), clamping a load to be transported, for example in the form of a roller (FIG. 3), or pivoting a held load (FIG. 4).

(9) Since, with industrial trucks it is mandatory that the driver provide additional approval before hazardous movements, a locking function can also be provided for tilting the mast 22 when a load 28 is lifted. When there is a locking function, a forward tilt is only possible after a certain load height when the driver has locked this function.

(10) FIG. 2 shows an operating lever 30 that can be pivoted along the A and B axes. The operating lever 30 may comprise a ball-shaped head on which the palm of the user's hand rests. In contrast to the base 32, the operating lever 30 may comprise an elastic sleeve 34 on its bottom that permits a movement of the lever 30. An unlocking lever or switch 36 may be positioned close to the operating lever 30. The unlocking lever can be actuated along the double arrow C in order to move the unlocking lever into an unlocked state.

(11) Different vehicle functions can be saved by actuating the operating lever 30 along either the A or B axes. By a movement in the plane covered by both axes, both functions can be overlapped. A resetting force can be generated with the resetting device for each of the A and B axes. The resetting force may be generally proportional to the deflection of the operating lever 30 in order to give the operating person a haptic feedback. In an embodiment, an operating lever with one-dimensional actuation can also be provided.

(12) FIG. 3 shows a clamping attachment that comprises two flat box-shaped clamps 38. The distance D between the clamps 38 can be adjusted by two adjusting cylinders 40. The clamps 38 may be configured to move along a load carriage 42, which is attached in a height-adjustable manner on a lifting mass 44. The distance D between the clamps 38 may be adjusted by actuation of the operating lever 30 (FIG. 2) along the A axis. In this case, actuating the operating lever 30 along the A axis is only possible when the unlocking apparatus 36 has been actuated beforehand to enable adjustment of distance D. Otherwise, the actuation of the operating lever 30 along the A axis is locked.

(13) FIG. 4 shows a rotatable fork carriage 46 that is rotatably mounted to a load carriage 48 by a rotating unit (not visible) and is configured to rotate about an axis in a direction E. The load carriage 48 is adjustable in height along the lifting mast 50. Rotating or pivoting the rotatable fork carriage 46 along the direction E can be used to pour out bulk goods or liquids that are arranged in a container on the rotatable fork carriage 46. Other uses of the rotatable fork carriage 46 are also conceivable. A rotary movement along direction E is also locked in this case and can only be activated when the associated unlocking device has been actuated.

(14) FIG. 5 shows a fork adjuster in which the distance F between the forks 52 and 54 can be adjusted by two adjusting cylinders 56. The adjusting cylinders 56 with the forks 52, 54 are arranged on a load carriage 58 that can be adjusted in height along the lifting mast 60. Adjustment of the distance F between the forks 52, 54 can be locked by an unlocking switch 36 (FIG. 2). It is also possible to provide a load sensor for the forks 52, 54. The load sensor detects a load 28 (FIG. 1) on the forks 52, 54. When there is a load 28 (FIG. 1) on the forks 52, 54, adjustment of distance F between the forks 52, 54 is in principle locked. The distance F can only be adjusted when there is no load 28 (FIG. 1) on the forks 52, 54. If a load sensor is used, it is also possible for an adjustment of distance F to be directly released when there is no load 28 (FIG. 1). It is also possible to require actuation of an unlocking switch when there is no load 28 (FIG. 1) in order to adjust the distance between the forks 52, 54.

(15) FIG. 6 shows the curves (or lines) 62a, 62b of a resetting force depending on the deflection of the operating lever 30 (FIG. 2). The normal force curves drawn with a continuous line correspond to a resetting force of 100% with 100% deflection. The resetting force is plotted here without a sign as an absolute amount in arbitrary units. Given a deflection of +20%, the resetting force along line 62a is the same size as the resetting force along line 62b; both resetting forces are aligned to reset the operating lever in its home position with 0% deflection.

(16) In the invention, the resetting force is adjusted along the dashed curve 64a, 64b. The curve 64a causes a very large resetting force to be already experienced upon a minimum deflection in a positive direction so that further actuation of the operating lever is impossible. The steep curves 64a, 64b function like end stops and accordingly block actuation of the operating element in the corresponding direction. As shown in FIG. 6, the blocking occurs optionally for individual directions. It is possible to a stipulate a curve of 62b and 64a, whereby there is only blocking in a positive deflection. Likewise by the combination of 64b and 62a, there can be a one-sided block for a negative deflection.

(17) The particular advantage of using the resetting device is that it can be flexibly used in the operating element.

(18) In a development of the curve of the resetting force shown in FIG. 6, the slope of the resetting force curves 64a, 64b can be varied so as to pulse. By varying the resetting forces over time, an operating person who presses the operating lever against the resetting force experiences a pulsing resetting force which moreover reminds him that the function is blocked.

REFERENCE LIST

(19) 10 Industrial truck 12 Drive part 14 Load part 16 Front wheel 18 Rear wheel 20 Articulation point 22 Lift mast 24 Tilt cylinder 26 Load bearing means 28 Load 30 Operating lever 32 Base 34 Elastic sleeve 36 Unlocking apparatus 38 Box-shaped clamp 40 Adjusting cylinder 42 Load carriage 44 Lift mast 48 Load carriage 50 Lift mast 52 Forks 54 Forks 56 Adjusting cylinder 58 Load carriage 60 Lift mast 62a Resetting force 62b Resetting force 64a Resetting force 64b Resetting force