GB2186060A

GB2186060A - Apparatus for adjusting the steering wheel of a vehicle

Info

Publication number: GB2186060A
Application number: GB08701823A
Authority: GB
Inventors: Hans-Friedrich Krull
Original assignee: Jungheinrich Unternehmensverwaltung KG
Current assignee: Jungheinrich AG
Priority date: 1986-02-03
Filing date: 1987-01-28
Publication date: 1987-08-05
Also published as: GB8701823D0; FR2593764A1; FR2593764B1; SE464574B; DE3603173C1; SE8700130D0; GB2186060B; SE8700130L

Abstract

The apparatus for adjusting the steering wheel (8) of a vehicle, particularly of an industrial truck, comprises a steering column (7), which is rotatably mounted in a guide bushing (3), which has associated with it two adjusting slots (21, 22), that extend at an angle to each other. A guide pin (23) extends through both said slots. Fixing means particularly clamping means (24, 25) are provided, which serve to fix the guide pin and the bushing in an adjusted position along the slots. One (21) of the slots is provided in a bracket (2), which is fixed to the structure of the vehicle. The guide bushing is guided along the two slots and is held against a pivotal movement. The two slots extend at a fixed angle to each other. <IMAGE>

Description

SPECIFICATION Apparatus for adjusting the steering wheel of a vehicle This invention relates to apparatus for adjusting the steering wheel of a vehicle, particularly of an industrial truck, comprising a steering column, which is rotatably mounted in a guide bushing, which has associated with it two adjusting slots that extend at an angle to each other, a guide pin extending through said slots, and fixing means, particularly clamping means, which serve to fix the guide pin and the bushing in an adjusted position along the slots, one of which is provided in a bracket, which is fixed to the structure of the vehicle.

In such a known apparatus, known from Published German Application 33 00 268, the other slot is formed in the guide bushing and a pivot pin is provided, which extends through both said slots. The slot formed in the guide bushing has the same direction as the other slot, which will be described hereinafter as the first slot, and the slot in the guide bushing permanently extends in the axial direction of the guide bushing. Because the two slots cooperate with a common pin the guide bushing cannot only be adjusted along one slot or the other but can also be pivotally moved as desired so that the position of a steering wheel on the steering column will be rather undefined. Specifically, the steering wheel in different adjusted positions will extend in different directions relative to the driver in dependence on the elevation of the steering wheel.

The same result will also be obtained if special locking slots are provided to assist the holding in the clamped position by pairs of cooperating racks and pinions associated with respective slots.

Such a change of the orientation of the steering will adversely affect the safety of the driver, particularly because it has been found that the steering wheel has suitably a constant inclination regardless of the height of the driver.

The inclination of the steering wheel is also changed by a steering wheel adjusting apparatus disclosed in Published German Application 25 11 901. In that apparatus an upper part of the steering column is guided in a bearing, which is pivoted to the vehicle. In that known design a telescopically extensible intermediate shaft is disposed below said swivel bearing and is connected to two universal joints, which are required to effect a certain displacement during a pivotal movement of the upper part of the steering column about the pivot.

For instance, in Published German Application 24 30 604 it is disclosed that the structural expenditure involved in a pivotal mounting of the upper part of the steering column can be eliminated if a hydraulic steering booster provided with hose fittings is mounted on that part below the pivot.

Published German Application 31 07 459 discloses an adjusting apparatus which also comprises a hydraulic steering booster, which is mounted on a steering column. But that steering column is mounted in a pivoted frame, one pivot of which is pivoted to a bracket that is secured to the vehicle structure whereas the other pivot is spaced apart from and parallel to the first pivot and carries a mounting plate for connection to the steering column provided with the steering wheel.

A pivotal movement only of the mounting plate about the other pivot will change the direction of the steering wheel or its angle to the horizontal. Whereas that angle may be maintained if a pivotal movement about tne first pivot is effected at the same time, the steering wheel will be laterally shifted in that case in dependence on the dimensions of the frame. That lateral shift is inherent in that arrangement and does not permit an adjustment of the steering wheel to any desired position.

Besides, that design is expensive.

The invention is based on the recognition that an adjustment of the steering wheel to a position which is convenient for the driver will be desirable. This is particularly applicable to industrial trucks, where the space is confined e.g., in case of a high-lift truck having a shiftable mast and a transverse seat,-because said confined spaced does not permit an adequate adjustment of the driver's seat.

For this reason it is an object of the invention so to improve an apparatus which is of the kind stated first hereinbefore that a predetermined inclination of the steering wheel will be maintained in case of an adaptation of the steering column and of the steering wheel relative to the driver's seat to change the elevation and the lateral spacing of the steering wheel.

That object is accomplished in that the guide bushing is guided in the two slots and is held therein against a pivotal movement and the two slots extend at a fixed angle to each other. As a result, the steering column can be axially adjusted as desired and can be translated, i.e., it can be moved parallel to itself whereas its orientation is maintained. The steering wheel will always have the same inclination from the horizontal.

The first slot, which serves to change the length of the steering column, is suitably formed in the bracket that is fixed to the vehicle structure and said slot is parallel to the steering column. That arrangement is simple, stable and safe.

In a particularly preferred arrangement, a guide member is guided in the first slot along the steering column and is held against rotation in said first slot and constitutes a guide for a slider, to which the guide bushing is fixed and which has a second slot that extends at an angle to the first slot. That ar rangement provides a particularly desirable mechanism for imparting to the steering column the above-mentioned translation whereas the orientation of the guide bushing will be maintained. Obviously the guide bushing may be adjusted relative to the slider and may be fixed in an adjusted position. This may be effected by means of screw joints.

Although the second slot may extend in any desired angular direction, it is preferably horizontal. In that case the translation of the steering column can be particularly easily effected and, in particular, need not be accompanied by a change of the adjustment along the first slot. This will result in the advantage that both slots are provided on the bracket and can be adjusted to any desired orientation relative to each other.

In a desirable embodiment the slider is guided in a U-shaped recess of the guide member and the latter is guided in the first slot by means of spaced apart cheese-head screws. This will ensure a stable guidance by simple means.

The guide pin is suitably a part of a fixing screw, which is provided with a finger nut and has an abutment head and is adapted to fix a certain adjustment along the slots. Additional clamping means may be provided in the screw assembly.

In another desirable embodiment the bracket is double-walled and is formed in its wall portions with two parallel slots, which constitute the first slot and extend in the longitudinal direction of the steering column. Between said wall portions the guide member is displaceable in said parallel slots and the slider is guided in the second slot, which is formed in the guide member and extends at an angle to the first slot. That arrangement will be stable and will oppose canting.

In an arrangement within the scope of the invention the steering column is connected in known manner to an intermediate shaft by means of a universal joint and said intermediate shaft is telescopically extensible and is connected by another universal joint to a steering gear shaft. In another suitable embodiment a fluid-operable steering booster is mounted on the steering column.

The invention will now be explained with reference to an example, which is diagrammatically shown on the drawing, in which Figure 1 is a diagrammatic, partly sectional view showing a steering column mounted on a bracket of a vehicle, Figure 2 is a sectional view taken on line 1111 in Figure 1, Figure 3 is a corresponding diagrammatic, partly sectional elevation showing a steering column provided with a steering booster that is different from that shown in Figure 1.

Figures 1 and 2 show a stand 1, which is mounted in a vehicle, not shown, and carries a bracket 2, on which a guide bushing 3 is guided. A steering column 7 is rotatably mounted in said guide bushing 3 by means of a rolling element bearing 4 and is fixed at one end to a first universal joint 5 and at the other end to a retaining ring 6 so that the steering column is axially fixed. A steering wheel 8 is mounted on the top of the steering column and is adjusted to extend at an angle 9 to the horizontal. That angle depends on the axial direction of the steering column 7.

A telescopically extensible intermediate shaft 10 is connected to the first universal joint 5 and is connected at its lower end by a second universal joint 11 to a steering gear shaft 12. The telescopically extensible intermediate shaft is provided, e.g., with splines between its axially displaceable parts.

The steering column 7 described thus far is adjusted to extend in a specially selected direction, which involves a certain inclination of the steering wheel 8.

The guide bushing 3 is fixed to the slider 13, which is guided on the bracket 2. In accordance with Figure 2 the bracket 2 comprises two wall portions 14 and 14', between which the slider 13 is disposed. A guide member 15 is also guided between the wall portions and as is apparent from Figure 2 that guide member has a U-shaped recess 16, in which the top and bottom edges 17, 18 of the slider 13 are displaceable in a fixed direction. The guide member 15 is provided with projections, which in the embodiment shown by way of example consists of cheese heads 19, 20 of inserted cheese-head screws. Said projections are guided in the first slot 21 of the bracket and hold the guide member 15 against rotation. The other wall portion 14' of the bracket 2 is formed with a slot 21', which corresponds to the slot 21 and which may also receive guiding projections of the guide member 15.

Owing to this design the guide bushing 3 is held so that its axial direction is constant. Because the slot 21 is parallel to the axial direction of the steering column, particularly of the upper part of the steering column, the guide bushing can be moved to increase or decrease the length of the steering column.

The U-shaped recess 16 in the guide member 1 5 is so designed that the slider can be moved in a horizontal direction. The slider 13 is formed with a second slot 22, which extends in the horizontal direction in which the slider is adjustable.

A fixing screw 23 provided with a finger nut 24 extends through the two slots 21 and 22 and the adjacent portions of the wall of the bracket 2. Under its abutment head 25 the fixing screw has a square portion 26, which is non-rotatably mounted in the slot 21 so that the fixing screw can be tightened by a turning of the finger nut and the arrangement can thus be clamped in a fixed position.

It will be apparent that when the fixing screw has been loosened the slider 13 can be displaced along the slot 22 so that the steering column 7 can laterally displaced, e.g., to the position 7' indicated in phantom. Such a shifting involving no change of the orientation will result in an increase of the length of the telescopic intermediate shaft 10. For instance, in the illustrated embodiment the swivel pin 27 of the first universal joint 5 will move to the position 27'. If the guide member 15 were moved to its lowermost position along the slot 21, the swivel pin 27 would assume the position 27" and the steering wheel 8 would assume the position 8". Upon a movement of the slider 13 to the right that swivel pin would assume the position 27"' and the steering wheel would assume the position 8"'. The position 27' corresponds to the adjusted position 8' of the steering wheel.

With slots having the illustrated dimensions, the range of adjustment defined by the phantom line 28 will be obtained. The steering wheel can be adjusted to any position within that range.

In the embodiment shown in Figure 3 the steering column 7 is provided below the guide bushing 3 with a control device 29 consisting of a fluid-operable steering booster, which has a top edge that constitutes also an abutment for the guide bushing 3.

Claims

1. Apparatus for adjusting the steering wheel of a vehicle, particularly of an industrial truck, comprising a steering column, which is rotatably mounted in a guide bushing, which has associated with it two adjusting slots that extend at an angle to each other a guide pin extending through said slots, and fixing means, particularly clamping means, which serve to fix the guide pin and the bushing in an adjusted position along the slots, one of which is provided in a bracket, which is fixed to the structure of the vehicle, characterized in that the guide bushing is guided in the two slots and is held therein against a pivotal movement and the two slots extend at a fixed angle to each other.

2. Apparatus according to claim 1, characterized in that a first slot is parallel to the steering column and is provided in the bracket that is fixed to the vehicle structure.

3. Apparatus according to claim 1 or 2, characterized in that a guide member is guided in the first slot along the steering column and is held against rotation in said first slot and constitutes a guide for a slider to which the guide bushing is fixed and which has a second slot that extends at an angle to the first slot.

4. Apparatus according to claim 1 or 2, characterized in that the second slot is horizontal.

5. Apparatus according to claim 3 or 4, characterized in that the slider is guided in a U-shaped recess of the guide member and the latter is guided in the first slot by means of spaced apart cheese-head screws.

6. Apparatus according to any of claims 1 to 5, characterized in that the guide pin is a part of a fixing screw, which is provided with a finger nut and has an abutment head and is adapted to fix a certain adjustment along the slots.

7. Apparatus according to any of claims 1 to 6, characterized in that the bracket is double-walled and is formed in its wall portions with two parallel slots, which constitute the first slot and extend in the longitudinal direction of the steering column, the guide member is displaceable in said parallel slots between said wall portions and the slider is guided in the second slot, which is formed in the guide member and extends at an angle to the first slot.

8. Apparatus according to any of claims 1 to 7, characterized in that the steering column is connected in known manner to an intermediate shaft by means of a universal joint and said intermediate shaft is telescopically extensible and is connected by another universal joint to a steering gear shaft.

9. Apparatus according to any of claims 1 to 7, characterized in that a fluid-operable steering booster is mounted on the steering column.

10. Apparatus for adjusting the steering wheel of a vehicle, substantially as described hereinbefore with reference to and as shown on the drawings.