EP0411335B1 - Control element for ground transport vehicles - Google Patents

Abstract

The disclosure relates to rotary handle controls using control circuits for controlling powered industrial trucks particularly stacking vehicles. Specifically, hand controls to effect a simultaneous actuation of several functions with one hand are disclosed. The circuitry embodys the use of potientiometer shafts to allow for one hand control.

Description

The invention relates to an operating element for industrial trucks, preferably forklift trucks, with a rotary handle for the stepless actuation of a driving gear and with a lifting gear, the rotary handle being designed as a multifunctional handle for one-hand operation of all the steering-independent functions of the industrial truck at the same time and in the area of movement of the thumb of an operator with one on both sides in the circumferential direction the twist grip adjustable signal transmitter is provided for actuating the lift circuit.

Known controls for industrial trucks are mostly divided into several functions. As soon as more than one vehicle function has to be operated with such operating elements, both hands of the operating personnel are required for this. This prevents simultaneous steering of the vehicle, so that the operation of the vehicle functions in principle presupposes the state of the vehicle.

Operating elements are also already known in which a vehicle function, for example the driving commands, is actuated steplessly via a rotary handle, and another vehicle function, for example the lifting and lowering of the load carrier, is triggered by actuation of pressure or rocker switches which are in the vicinity lie outside the twist grip. This gives the operator the difficulty of operating either the twist grip or the pressure or rocker switch, since the latter often come out of the effective range of the thumb usually intended for this when the twist grip is turned and therefore cannot be operated at the same time. This prevents an overlay of these vehicle functions or the resulting simultaneous movement sequences. Apart from this, such devices usually require a number of separate control circuits corresponding to the individual switches.

Controls where push buttons or push buttons are already directly on the rotary handle, e.g. B. the front thereof, are arranged, exclude a stepless function control.

This is also the case with a pilot control device disclosed in DE-U-78 22 523, which consists of a T-shaped actuating lever and a plurality of push buttons or selector levers arranged thereon, which are cumbersome to operate and do not rule out incorrect operation.

From US-A-3 823 616 a handle control device for forklift vehicles is known which serves the driver as a handle on the one hand and with which on the other hand at least three control functions can be triggered by one hand, a first control signal by turning a handle, a second Control signal can be generated by means of a rotary controller arranged on the handle and rotatable and thumb-actuated relative to it, and finally a third control signal by depressing the entire handle control device against a spring plate. A major disadvantage of this facility is in that, by actuating the rotary control, a cam disc cooperating on the periphery with a plurality of microswitches is rotated and thus a stepless regulation is prevented and the use thereof is therefore limited to only contactive signal transmitters. Since each of the microswitches has its own control circuit, this device requires an unacceptable expenditure on circuitry and control technology, which increases with the number of gradation steps. Apart from this, the holding function and the triggering of the third control signal are adversely affected by the arrangement of the handle control device on the resilient spring plate in a mutual manner. Due to the requirement for the rotary handle to be supported on both sides, certain structural conditions and an ergonomic arrangement on the control panel cannot always be taken into account.

Proceeding from this, the object of the invention is to create an operationally reliable and, in particular, ergonomic control element of high stability for industrial trucks, preferably for a forklift vehicle, with little effort in terms of resources and costs, which enables a simultaneous triggering of several vehicle functions with one hand, without the requirement to have to release the hand from the control element at any time and that should also serve as a handle for the driver while the industrial truck is moving.

The object is achieved in that the driving and lifting circuits are arranged opposite each other at both ends of the rotary handle and are equipped with stepless signal generating means, the actuating shafts of which are rotatably integrated independently of one another in the rotating handle, the actuating shaft of the driving circuit signal generating means with the rotary handle and the Actuating shaft of the lifting circuit signal generating means is spring-loaded to the signal transmitter, and the lifting circuit is fixedly connected to one end of the rotary handle.

The ergonomic integration of the actuator for the lift control directly into the control element for the drive control enables simultaneous one-hand operation of both and the resulting superimposed motion sequences of the hoist and industrial truck, without any interruption of the simultaneous steering process of the industrial truck with the other hand. Due to the opposite arrangement of travel and lift control at both ends of the twist grip and the integration of their control shafts in the twist grip, a particularly space-saving, compact design can be achieved, which requires a minimum of circuitry complexity and is characterized in particular by short travel ranges and stepless controllability.

In a further development of the inventive concept, the rotary handle on the industrial truck or parts thereof is mounted on one side so that an ergonomic arrangement - both in and transversely to the direction of travel - favors industrial trucks of various types, the rotary handle due to its stable design when starting or braking as well as when cornering In an exemplary function, the industrial truck can also be used as a handle and driver support, without running the risk of impairing existing functional regulations or even unintentionally triggering new ones.

A preferred embodiment of the invention is characterized in that the signal transmitter is designed for ease of use as a slider adjustable on both sides in the circumferential direction, which not only facilitates stepless actuation of the lift switch, but also advantageously the use of signal generating means of contactless design, for example Hall Generators allowed.

The latter advantage results in particular from a preferred geometric construction, according to which the signal transmitter is arranged in the center of a circular segment-shaped recess in the rotary handle and is provided with a radial adjusting tongue which extends the potentiometer shaft centrally in the longitudinal axis of the rotary handle.

Further advantageous embodiments of the invention are set out in claims 7 to 9 and in the following description.

• Fig. 1 einen Längsschnitt durch einen Drehgriff eines erfindungsgemäßen Bedienungselementes,
• Fig. 2 einen Querschnitt durch den Drehgriff gemäß der Schnittlinie A-B in Fig. 1,
• Fig. 3 eine auszugsweise Draufsicht auf den Drehgriff gemäß Fig. 1.

The invention permits numerous embodiments. One of them is shown as an example in the drawing using several figures and described below. It shows:

• 1 shows a longitudinal section through a rotary handle of an operating element according to the invention,
• 2 shows a cross section through the rotary handle according to section line AB in FIG. 1,
• 3 is a partial top view of the twist grip according to FIG. 1.

1 , a twist grip 1 is equipped with a non-slip grip surface 2, which preferably extends over the entire circumference and the entire length of the twist grip 1. To increase the grip, the gripping surface 2 is provided with a rough or corrugated and possibly rubberized covering or instead with a knurled surface structure. At one end of the rotary handle 1 there is a shaft shoulder 3 into which an outer annular groove 4 is embedded. Centrally in the shaft paragraph 3 is as Square 5 formed blind hole introduced.

A bearing pot 8 is arranged on the shaft shoulder 3 by means of a ball bearing 7 and is designed as a flange 9 on its outer diameter for the purpose of attachment to the industrial truck. Ball bearing 7 and bearing cup 8 are secured against axial displacement by means of two circlips 10 and 11, an outer circlip 10 being located in the outer annular groove 4 of the shaft shoulder 3, and an inner circlip 11 being embedded in an inner annular groove 13 of the bearing cup 8.

A drive circuit 18 is screwed onto the end of the bearing pot 8 by means of a bearing cover 14. The driving circuit 18 includes u. a. a potentiometer 15 with a potentiometer shaft 16 and generates driving signals, such as "FORWARD", "STOP" and "REVERSE", for controlling at least one driving motor in a known manner via pulse control. The potentiometer shaft 16 is designed as a square. It extends through a bore 17 of the cover 14 and is guided in the inner square 5 of the shaft shoulder 3.

At its end opposite the driving switch 18, the rotary handle 1 extends into a bearing shell 19 with an inner recess 20. A spring-loaded ball catch 41 is arranged in the wall of the bearing shell 19, the spring tension of which can be changed by means of an adjusting screw 42. The recess 20 is followed by a bearing seat 21 which merges into a longer blind hole 6.

A bearing cap 22 which closes the same and has a central bore 23 is screwed onto the bearing shell 19. On the bearing cover 22, a lifting circuit 24 is attached, which u. a. contains a potentiometer 25 with a potentiometer shaft 26 and generates stroke signals, such as "RAISE", "STOP" and "LOWER", in a known manner for controlling at least one lifting motor.

Driving circuit 18, lifting circuit 24, potentiometers 15 and 25, pulse controls and the driving and lifting motor are known, commercially available components and therefore not, or only shown and described schematically.

The potentiometer shaft 26 extends through the bore 23 of the bearing cover 22 over the entire length of the blind bore 6 and is supported at the end in a bore 36 which is made centrally in the bottom of the blind bore 6. The potentiometer shaft 26 is formed over the entire length of the blind bore 6 as a square shaft and the shaft end mounted in the bore 36 is concentric. In the bearing shell 19, the potentiometer shaft 26 is guided in a bearing bush 27, which in turn is supported by means of a ball bearing 28 arranged on the bearing seat 21. In front of the bearing bush 27, the potentiometer shaft 26 is secured against axial displacement by a locking ring 29.

In the lateral surface of the bearing bush 27 - distributed over its circumference - dome-shaped, conical or triangular-shaped locking recesses 43 are inserted, which interact with the spring-loaded ball catch 41 of the bearing shell 19. Straighten it the number and distance of the locking recesses 43 according to the desired number of fine gradations of the adjustment steps, while their perceptibility can be varied up to the stepless transition based on the depth of the locking recesses 43 and / or the spring force of the ball catch 41 ( FIG. 1 ) .

Arranged in the recess 20 of the bearing shell 19 on the bearing bush 27 is a return spring 30 designed as an expansion spring, one end of which rests against a stop 31 fixed in the bearing shell 19 and the other end of which rests against a driver 32 fastened in the bearing bush 27 ( FIG. 1 ) . In an equivalent, but not shown, manner, the aforementioned potentiometer shaft 16 is spring-loaded.

So that the blind holes, bores and recesses may only have to be finished, the rotary handle 1 is preferably cast, for example in cast aluminum. Of course, the rotary handle 1 can also be made as a turned part.

As shown in Fig. 2 , in the region of the blind hole 6, preferably radially aligned with the bottom, a circular segment-shaped recess 34 is embedded in the circumference of the rotary handle 1. Arranged in this is a signal transmitter 35, which is preferably designed as a slider with a knurled surface and, according to FIG .

The signal generator 35 is provided with an adjusting tongue 38 which extends radially into the blind bore 6 of the rotary handle 1 and into which a bore in the form of an inner square 39 is embedded. The square area of the potentiometer shaft 26 extends centrally in the longitudinal axis 40 of the rotary handle 1 through the inner square 39. The adjusting tongue 38 of the signal transmitter 35 is secured on its underside with respect to the potentiometer shaft 26 in a known manner with a locking screw, not shown.

Starting from a central zero position 37, the signal transmitter 35 can be displaced continuously or finely graduated against the force of the return spring 30 on both sides in the circumferential direction by a certain angle (radian measure), as is indicated schematically by a dash-dot line in FIG. 2 .

The operation of the control element according to the invention is explained in more detail below.

By turning the rotary handle 1 on the left or right-hand side - preferably by means of the operator's right hand - the potentiometer shaft 16 of the travel switch 18 is rotated and thereby alternating voltage values are generated which, after their processing in the pulse control, are used to control the travel motor. Since the other, preferably left hand is used to steer the industrial truck, it was previously only possible to carry out a superimposed lifting mechanism movement while driving at the same time as the generation of the driving signals.

By moving the signal transmitter 35 integrated directly into the rotary handle 1 with the thumb, the operator can now generate additional superimposed hoist signals without the need to take his hand off the operating element, so that simultaneous steering, Driving as well as a hoist actuation of the industrial truck is made possible.

The choice of the depth of the locking recesses 43 in connection with the choice of the height of the spring preload of the ball catch 41 which snaps into it when the signal transmitter 35 is displaced enables the driver to perceive the adjustment steps in a highly perceptible manner, in which the respective locking positions can only be achieved by using increased finger force let bridged, as well as a relatively infinitely variable and no longer detectable shift control without using measuring technology.

As shown in FIG. 1 , the spring-loaded ball detent 41 can be brought out of engagement with the detent recesses 43 by means of the set screw 42 or other mechanical means, which enables the signal transmitter 35 to be moved absolutely continuously. This can also be done in a simple manner in such a way that a rest position, not shown, is provided, into which the spring-loaded ball catch 41 can be lifted completely out of its catch position in order to relieve and release its catch ball.

Since the rotation of the potentiometer shafts 16 and 26 takes place against spring loading, the operator can, in an emergency, bring the initiated movement sequences to a standstill individually or together by simply releasing the rotary handle 1 and / or the signal generator 35. For example, the signal generator 35 is automatically returned to its zero position 37, since the force of the return spring 30 is far greater than that of the ball catch 41 and the latter thus cancels. In principle, this means that operating errors are completely ruled out and the operator can fully concentrate on the movement sequences of his vehicle that he has initiated, or the loading and unloading processes.

Due to the robust cast construction, the rotary handle 1 can be used by the driver in a kind of additional function as a stabilizing handle or as a side support during driving movements - especially when accelerating and decelerating as well as when cornering.

The invention is of course not limited to the exemplary embodiment shown in the figures and laid down in the description. It goes without saying that numerous constructive modifications, such as. B. different shape and arrangement of the signal generator 35 on the rotary handle 1, the use of equivalent actuators or locking means as well as the use of signal generators working on a different physical basis, are also within the scope of the invention, as are the fine grading of the actuating steps by using cam-operated limit switches.

Parts list

1

Twist grip

2nd

Grip surface

3rd

Shaft shoulder

4th

Ring groove

5

Inside square

6

Blind hole

7

ball-bearing

8th

Storage pot

9

flange

10th

Circlip

11

Circlip

13

Ring groove

14

Bearing cap

15

Potentiometer

16

Potentiometer shaft

17th

drilling

18th

Driving gear

19th

Bearing shell

20th

Recess

21

Camp seat

22

Bearing cap

23

drilling

24th

Lift switching

25th

Potentiometer

26

Potentiometer shaft

27

Bearing bush

28

ball-bearing

29

Circlip

30th

Return spring

31

attack

32

Carrier

34

Recess

35

Signal generator

36

drilling

37

Zero position

38

Tongue

39

Inside square

40

Longitudinal axis

41

Ball catch

42

Set screw

43

Notch

Claims (9)

1. Operating element for ground transport vehicles, preferably stacking vehicles, having a turning handle (1) for the continuous actuation of a travel circuit (18), and having a lifting circuit (24), wherein the turning handle (1) is formed as a multipurpose handle for the one-handed simultaneous operation of all the functions of the ground transport vehicle which are independent of the steering and is provided, in the range of movement of the thumb of an operator, with a signal generator (35) which is adjustable on both sides in the peripheral direction of the turning handle (1) to actuate the lifting circuit (24), characterised in that the travel circuit and the lifting circuit (18 and 24) are disposed opposite one another at either end of the turning handle (1), and are provided with continuous signal generating means (15 and 25), of which the setting shafts (16, 26) are integrated in the turning handle (1) such that they can be rotated independently of one another, wherein the setting shaft (16) of the travel circuit signal generating means (15) is coupled in a rotatable and spring-loaded manner to the turning handle (1), and the setting shaft (26) of the lifting circuit signal generating means (25) is coupled in a rotatable and spring-loaded manner to the signal generator (35), and wherein the lifting circuit (24) is rigidly connected to one end of the turning handle (1).
2. Operating element according to Claim 1, characterised in that the turning handle (1) is mounted on the ground transport vehicle or on parts thereof on one side in an overhung manner.
3. Operating element according to Claim 1 and/or Claim 2, characterised in that the signal generator (35) is formed as a push controller which is continuously adjustable on both sides in the peripheral direction.
4. Operating element according to one or more of the preceding claims, characterised in that the signal generating means (15, 25) are of the contact type of construction, for example potentiometers.
5. Operating element according to one or more of Claims 1 to 4, characterised in that the signal generating means (15, 25) are of the contactless type of construction, for example Hall generators.
6. Operating element according to one or more of the preceding claims, characterised in that the signal generator (35) is disposed in the centre of an arcuate recess (34) of the turning handle (1), and is provided with a radial setting tongue (38), through which the setting shaft (26) extends, centrally in the longitudinal axis (40) of the turning handle (1).
7. Operating element according to one or more of the preceding claims, characterised in that the setting shaft (26) is guided, mounted on ball-bearings, in a mounting socket (27) of the turning handle (1), on which mounting socket there is disposed a restoring spring (30), of which the one end abuts an abutment (31) secured on the turning handle (1), and of which the other end abuts an entraining means (32) secured in the mounting socket (27), whereby the signal generator (35) is automatically returned to its zero position (37) after release.
8. Operating element according to one or more of the preceding claims, characterised in that a settable, spring-loaded ball catch (41) is disposed in the bearing shell (19) and is connected for operation to the catch recesses (43) of the mounting socket (27), wherein the ball catch (41) can be selectively disengaged from an engaged position into a rest position.
9. Operating element according to one or more of the preceding claims, characterised in that on the end of the turning handle (1) that is located opposite the lifting circuit (24), a bearing shell (8) is disposed mounted on ball-bearings, and is formed on its periphery as a flange (9) for securing to the ground transport vehicle, and on which bearing shell there is secured, by means of a mounting cover (14), the drive circuit (18) with the signal generator means (15), of which the setting shaft (16) is mounted in a square socket (5) which has been let into the turning handle (1).

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