CA1295921C

CA1295921C - Apparatus for selective mechanical operation of control devices andutility vehicle equipped with such apparatus

Info

Publication number: CA1295921C
Application number: CA000564124A
Authority: CA
Inventors: Gert Kupplich; Hans Gisler
Original assignee: REBERLE REG TREUUNTERNEHMEN SCHAAN
Current assignee: REBERLE REG TREUUNTERNEHMEN SCHAAN
Priority date: 1987-04-15
Filing date: 1988-04-14
Publication date: 1992-02-18
Anticipated expiration: 2009-02-18
Also published as: DE8804607U1; CH672551A5

Abstract

ABSTRACT

In arms forming the forked end of a base plate, a shaft is rotat-ingly mounted. Disposed rotatingly and axially displaceably in the mid-region of the shaft is a first drum. On one side of the first drum, a second drum is rotatingly mounted on the shaft. On the other side of the first drum, a third drum is connected rotation-tight to the shaft.
The first drum has three circumferential grooves, and a driver pin pro-jects into the middle groove. This pin is fixed to a toggle lever which is connected to a piston rod of a hydraulic drive cylinder. Extending axially from each of the two end faces of the first drum is a cam in-tended to engage recesses in the second and third drums. A foot pedal is connected to the first drum by a Bowden cable; and depending on the posi-tion of the drum, the rotary motion produced by means of the foot pedal is transmitted to the second or third drum. This apparatus makes it pos-sible to simplify considerably the operation of a utility vehicle, there-by increasing driving safety.

Description

~ S~l APPARATUS FOR SELECTIVE MECHANICAL OPERATION OF CONTROL DEVICES AND
UTILITY VEHICLE EQUIPPED WITH SUCH APPARATUS

This invention relates to vehicle controls, and more particularly to apparatus for the selective mechanical operation of at least one of at least two control devices, of the type having an actuator.
The invention further relates to a utility vehicle equipped with such apparatus, of the type having an internal combustion engine, a hy-draulic pump rotationally connected thereto, a hydraullc traction motor connected to the latter, a hydraulic working motor for driving working equipment, and a lever for setting an at least approximately constant speed of the internal combustion engine.
Utility vehicles such as street-sweepers, road-sprinklers, snow-plows, and construction vehicles frequently have a hydraulic traction drive comprising an internal combustion engine, a controllable hydraulic pump, a hydraulic traction motor, and a hydraulic working motor for op-erating the equipment. During so-called ~automotive operation,~ the speed of the traction motor is controlled by means of an accelerator, as is customary in motor vehicles, to regulate the speed of travel. In so-called ~inch operation~ (simultaneous operation and slow travel) the speed of travel is regulated by means of a second pedal or a hand-lever for varying the angle of tilt of the hydraulic pump while keeping the motor and pump speeds substantially constant. For the driver of such a prior art utility vehicle, this means that, depending upon the mode of operation, he must use one pedal one time and another pedal another time, which complicates driving and may affect driving safety.
It is an object of this invention to provide improved apparatus whereby one of two control devices may be selectively operated by means of only one actuator.
A further object of the invention is to provide a utility vehicle equipped with such apparatus, thereby increasing operating safety.
To this end, the apparatus according to the present invention, of the type initially mentioned, comprises a shaft rotatingly mounted in a base plate, a first drum rotatable and axially displaceable about the ~ 5~2 1 mid-region of the shaft, which first drum is operatively connected to the actuator, a second drum rotatably mounted on the shaft on one side of the first drum, which second drum is operatively connectible to one of the control devices, a third drum disposed rotation-tight or rotatably on the shaft on the other side of the first drum, and a device for axially dis-placing the first drum on the shaft from a first position to a second po-sition and back, the first drum being rotationally connected to the sec-ond drum in the first position and to the third drum in the second posi-tion, and the first drum being operatively connected to the actuator, the second drum being operatively connectible to one of the control devices, and the third drum being operatively connectible to the other of the con-trol devices.
In the utility vehicle according to the present invention, of the type initially mentioned, the actuator of the apparatus is a pedal for accelerating or slowing down the utility vehicle, the first control de-vice is a device controlling the fuel feed to the internal combustion engine, the second control device is a device controlling the delivery of the hydraulic pump, and a limit switch is associated with the setting lever for exciting the winding of the solenoid valve when the setting lever is in a position other than the idling-speed position.
In a drawing which illustrates an embodiment of the invention, the sole figure is a diagrammatic perspective view of the apparatus and the main connecting elements with parts of a hydraulic drive.
The apparatus 1 shown in the drawing comprises a base plate 2, one end portion of which is forked. Extending through the two arms 3 and 4 of this end portion is a shaft 5 on which a first drum 6 is mounted rota-t;ngly and axially displaceably. On one side of the drum 6, a second drum 7 is disposed rotatingly, while on the other side a third drum 8 is mounted on the shaft 5 and connected rotation-tight thereto by means of a grub screw 9.
The drum 6 includes three circumferential grooves 10, 11, and 12.
Wound in the groove 10 is the end portion of a traction member 14 con-nected to a pedal 13. The traction member 14 is part of a Bowden cable 15, the compression-resistant sheath of which is secured at one end to a l~9S9;21 bearing block 16 of the pedal 13 and at the other end of a bracket plate 17. Projecting ;nto the groove 11 is a driver pin 18 secured to an angu-lar two-armed lever 19 which is pivoted about a bolt 20 rigidly connected to the base plate 2. The other end of the lever 19 is pivotingly con-nected to a piston rod 21 of a hydraulic drive cylinder 22, one end ofwhich is connected by a pivot pin 23 to the base plate 2.
Projecting axially from respective end faces of the drum 6 are cams 25 and 25. When the drum 6 is in the position shown in the draw;ng, the cam 25 is situated in a recess 26 in the second drum 7, whereby the drums 6 and 7 are connected to rotate jointly. Inside the cylinder 22 there is a spring (not shown) which holds the piston rod 21 in the position shown in the drawing when the cylinder 22 is not impinged upon by hydraulic oil. The cam 24 is intended to engage a recess 27 in the third drum 8 when hydraulic oil is supplied to the cylinder 22 from a pressurized-oil source 30 via a solenoid valve 28 and a pipeline 29. When this is the case, the drum 6 and the drum 8 are connected to rotate jointly.
Disposed in the circumferential groove 12 of the drum 6 is part of a tension spring 31, one end of which is secured to the drum 6 and the other end to the base plate 2. The spring 31 causes the drum 6 and the pedal 13 to return to their resting positions as shown in the drawing when no outside force is any longer exerted on the pedal 13.
The second drum 7 includes a circumferential groove 32 holding one end of a traction member 34 forming part of a Bowden cable 33, the other end being fastened to a switch lever 35 of an injection pump 36 of an in-ternal combustion engine 37.
If the pedal 13 is actuated when the drum 6 is in the positionshown in the drawing, a slide 38 moves in the direction indicated by ar-row 39. This causes the traction member 14 to move in the direction in-dicated by arrow 40, causing the drum 6 to rotate counterclockwise, as viewed in the drawing. This rotary motion is transmitted via the cam 25 to the second drum 7. As a result, the end portion of the traction mem-ber 34 in the groove 32 of the drum 7 is wound up, causing the rest of the traction member 34 to move in the direction indicated by arrows 41 and 42. The switch lever 35 is thereby pivoted counterclockwise, so that the more the pedal 13 is pressed down, the more the speed of the internal combustion engine 37 increases.
The output shaft (not shown) of the engine 37 is rotationally con-nected to the drive shaft 43 of a hydraulic pump 44 having an adjustable swash plate (not shown). The intake and outlet of the pump 44 are con-nected to a hydraulic traction motor (not shown). This hydraulic pump is designed for the automotive control; as the speed of the lnternal combus-tion engine increases, the angle of tilt of the swash plate of the hy-draulic pump becomes greater, so that the delivery and hence the speed of the hydraulic traction motor, thus the speed of vehicle, likewise in-crease. If the pedal 13 is released, the first drum 6 is rotated back toward the resting position by the tension spring 31, and the speed of the internal combustion engine 37, the angle of tilt of the swash plate of the hydraulic pump 44, and the speed of the traction motor--hence that of the vehicle itself--are reduced.
By exciting the winding of the solenoid valve 28, as described be-low, this valve is opened, and hydraulic oil is supplied to the driving cylinder 22 over the pipeline 29. The piston rod 21 is thereby pushed out, and the lever 19 pivoted counterclockwise. This causes the drum 6 to be displaced axially toward the third drum 8, whereupon the cam 24 en-gages the recess 27 in the drum 8. Thus the drum 6 is no longer rota-tionally connected to the drum 7 but to the drum 8. When the pedal 13 is thereafter pressed down, the rotary motion of the drum 6 produced thereby is transmitted to the third drum 8 and to the shaft 5.
Rigidly connected to one end of the shaft 5 is a lever arm 45. The other end of the lever arm 45 is connected via a traction member 46 to a setting lever 47 of a device 48 for setting the angle of tilt of the swash plate of the hydraulic pump 44. The traction member 46 forms part of a Bowden cable 49.
With the aid of the apparatus 1 described above, either the injec-tion pump 36 or the device 48 for adjusting the angle of tilt of the swash plate of the hydraulic pump 44 can be controlled with the pedal 13 as a function of the exciting of the solenoid valve 28. In another em-bodiment, not illustrated, the second drum 7 may also be displaced ~ ~s~

axially if it is desired to actuate two control devices simultaneously with one pedal 13.
The apparatus 1 described above is especially intended for a util-ity vehicle, e.g., a street-sweeper, comprising the internal combustion engine 37, the hydraulic pump 44, and the hydraulic traction motor (not shown). Such a utility vehicle may, for example, have rotary brushes and a suction unit which are driven at a substantially constant speed during operation of the vehicle.
For so-called automotive operation, i.e., for moving the vehicle from one workplace to another some distance away, the apparatus 1 assumes the position shown in the drawing, so that the speed of the engine 37, and thus the speed of the vehicle itself, is governed by actuation of the pedal 13. Upon arrival at the workplace, the pedal 13 is released to put the drum 6 into its resting position, and a hand-lever 50 is actuated.
This lever is connected by means of a Bowden cable 51 to a switch lever 35- of the injection pump 36 of the engine 37. By means of the hand-lever 50, the desired speed of the engine 37 necessary for proper opera-tion of the aforementioned brushes and suction unit can be set.
Associated with the hand-lever 50 is a limit switch 52 which is opened when the hand-lever 50 is in its resting position as shown in the drawing. If the hand-lever 50 is turned just a little in the direction indicated by arrow 53, the limit switch 52 closes, and the winding of the solenoid valve 28 is connected over a line 54 to a current source tnot shown) and excited. As stated above, this causes the piston rod 21 to move out, and the drum 6 is moved axially toward the drum 8. Further-more, via a connection 55 shown by a dashed line and a changeover mechan-ism 56, the angle of tilt of the swash plate of the hydraulic pump 44 is changed by the setting device 48 rather than by the speed of the pump.
Thereafter, when the pedal 13 is pressed down, the rotary motion of the first drum 6 is, as already explained, transmitted to the third drum 8 and further via the lever arm 45 and the traction member 46 to the set-ting lever 47. Thus, through actuation of the pedal 13, the delivery of the hydraulic pump 44 is governed and the speed of the vehicle con-trolled. During this time, the internal combustion engine 37, the 1295~

mentioned brushes and the suction unit run at a substantially constant speed, independently of the speed of the vehicle.
When the job is finished, the pedal 13 is released, and the hand-lever 50 is returned to its resting position. The winding of the sole-5 noid valve 28 is thereby de-energized and the valve closes. As a result, the spring (not shown) inside the drive cylinder 22 pulls the piston rod 21 back into the cylinder, so that the hydraulic oil is forced out of the cylinder chamber and through a pipeline 57 into a hydraulic-oil tank 58.
At the same time, the drum 6 is displaced toward the drum 7 by means of 10 the lever 19, whereupon the cam 25 engages the recess 26 of the drum 7 so that the motion of the pedal 13 is transmitted to the switch lever 35 of the injection pump 36.
With the utility vehicle described above, the s;ngle pedal 13 is used to vary the speed of the vehicle by varying either the speed of the engine 37 or the angle of tilt of the swash plate of the hydraulic pump 44, depending on the desired mode of operation. This considerably sim-plifies operation of the vehicle and increases driving safety.
Other embodiments, not illustrated, might have a simple mechanical means rather than the drive cylinder 22 for axial displacement of the first drum 6. The solenoid valve might also be reversed by means of a separately actuated changeover switch, and the drum 6 might also be equipped with a limit switch for preventing the winding of the solenoid valve 28 from being excited in any but the desired position when the hand-lever 50 is actuated.
Furthermore, the drums 7 and 8, or the lever arm 45, might be used, for example, to actuate or trigger electronic control elements or pressure-regulating units.

Claims

1. Apparatus for the selective mechanical operation of at least one of at least two control devices, comprising an actuator, a shaft rotatingly mounted in a base plate, a first drum rotatable and axially displaceable about the mid-region of the shaft and operatively connected to the actuator, a second drum rotatably mounted on the shaft on one side of the first drum and operatively connectible to one of the control devices, a third drum disposed either rotation-tight or rotat-ingly on the shaft on the other side of the first drum, and means for axially displacing the first drum on the shaft from a first position to a second position and back, the first drum being rotationally connected to the second drum in the first position and to the third drum in the second position, and the first drum being operatively connected to the actuator, the second drum being operatively connectible to one of the control de-vices, and the third drum being operatively connectible to another of the control devices.

2. Apparatus as defined in claim 1, wherein the first drum has three circumferential grooves, one end portion of a traction member con-nected to the actuator being disposed in the first groove, a driver pin of the axial-displacement means projecting into the second groove for ax-ially displacing the first drum, and at least part of a tension spring being disposed in the third groove, one end of the tension spring being connected to the base plate and the other end to the first drum for mov-ing the first drum into its resting position when the actuator is not operated.

3. Apparatus as defined in claim 1 or 2, wherein the axial-displacement means comprises a hydraulic cylinder-piston drive having a piston rod and a solenoid valve.

4. Apparatus as defined in claim 1, wherein a respective cam extends axially from each end face of the first drum, there being in each adjacent end face of the second and third drums nearest each respec-tive end face of the first drum a respective recess for receiving the as-sociated cam.

5. Apparatus as defined in claim 1 or 4, wherein the second drum has a circumferential groove for receiving part of the end portion of a traction member connectible to the first control device, a lever arm or an eccentric being rotationally connected to the third drum for acting upon the second control device.

6. Apparatus as defined in claim 4, wherein the second drum is axially displaceable by means of the actuator for simultaneously operat-ing two control devices.

7. A utility vehicle equipped with apparatus for the selective mechanical operation of at least one of at least two control devices, said apparatus comprising an actuator, a shaft rotatingly mounted in a base plate, a first drum rotatable and axially displaceable about the mid-region of the shaft and operatively connected to the actuator, a sec-ond drum rotatably mounted on the shaft on one side of the first drum and operatively connectible to one of the control devices, a third drum dis-posed either rotation-tight or rotatingly on the shaft on the other side of the first drum, and means for axially displacing the first drum on the shaft from a first position to a second position and back, the first drum being rotationally connected to the second drum in the first position and to the third drum in the second position, and the first drum being opera-tively connected to the actuator, the second drum being operatively con-nectible to one of the control devices, and the third drum being opera-tively connectible to another of the control devices, said utility vehi-cle having an internal combustion engine, a hydraulic pump rotationally connected thereto, a hydraulic traction motor connected to the hydraulic pump, a hydraulic working motor for driving a piece of equipment, and a lever for setting an at least approximately constant speed of the internal combustion engine, wherein the actuator of the apparatus is a pedal for accelerating or slowing down the utility vehicle, the first control device is a device controlling the fuel feed to the internal com-bustion engine, the second control device is a device controlling the de-livery of the hydraulic pump, and a limit switch is associated with the setting lever for exciting the winding of the solenoid valve when the setting lever is in a position other than the idling-speed position.

8. A vehicle as defined in claim 7, wherein the device con-trolling the fuel feed is an injection pump, the hydraulic pump is an ax-ial piston pump, and the device controlling the pump delivery is a device having a setting lever and governing the stroke of the piston of the ax-ial piston pump.

9. A vehicle as defined in claim 8, wherein the device con-trolling the pump delivery comprises means for changing over between a first mode of operation in which the pump delivery is a function of the speed of the hydraulic pump and a second mode of operation in which the pump delivery is a function of the position of the setting lever, said means for changing over between the first and the second mode of opera-tion being connected to the setting lever.