ADJUSTABLE STEERING COLUMN FOR VEHICLES

Abstract: An adjustable steering wheel shaft with means for adjustment of its length and inclination where a common control is provided for releasing or locking the length adjustment and tilting movement of the steering wheel shaft. The common control being a piston (II) being axially displaceable and/or pivotally supported in the column housing. Said piston (II) is biased to a position in which it exerts a force locking a first steering column tube (2) against axial displacement and prevents the hub (17) from rotating around its pivot axle. The piston is displaceable and/or pivotable by activation of a control (15)one position in which it admits axial displacement between said first steering column tube (2) and the housing and further to a second position where the other motions is admitted. Two distinct, spaced apart release positions are obtained, one for each one of said motions.

Description: The present invention relates to an adjustable steering wheel shaft for vehicles. There is a desire to be able to adjust and position the steering wheel shaft of a steerable vehicle in such a way that the steering wheel fitted to the steering wheel shaft is situated in a position within easy and comfortable reach for the user of the vehicle. This applies both to the first setting of the steering wheel shaft in a new vehicle and also to adjustment when the vehicle shall be used by someone else. In order to provide an adjustment which makes it possible for each user to achieve the individually best setting it is necessary to have a possibility of length adjustment of the steering wheel shaft as well as of its angular inclination. Steering wheel shafts adjustable in this manner are known in many different embodiments, whereby they however often are designed in a such a manner that it is necessary to actuate two different adjustment mechanisms in order to bring about a correct adjustment. There also has been developed adjustment mechanisms which from a single control can release both mechanisms which have to be actuated to provide adjustment, but these older adjustment mechanisms are generally very complex and therefore expensive, and the risks for damages and malfunctions are increased. THE PURPOSE AND MOST ESSENTIAL FEATURES OF THE INVENTION The object of the invention is to provide an adjustable steering wheel shaft for vehicles provided with means for adjustment of its length and means for adjustment of its inclination relative to the vehicle body, whereby the steering wheel shaft comprises a steering wheel shaft housing, a first steering column tube displaceably arranged in said housing and a second steering column tube, pivotably arranged relative to said steering wheel shaft housing, said first and second steering column tube being interconnected by said intermediate steering wheel shaft housing, the said second steering column tube at its end cooperating with the steering wheel shaft housing being provided with a hub, which is limitedly rotatable in a seat in the steering wheel shaft housing around a pivot axle located perpendicularly to the longitudinal direction of the tube and being adapted to be locked from rotation in a number of angular positions by means of a locking mechanism, whereby the steering wheel axle and the steering axle are interconnected by an angularly adjustable coupling and extend through the said first and second steering column tubes and steering wheel shaft housing, and where a common control is provided for releasing or locking the length adjustment and tilting movement of the steering wheel shaft resp., and which has a simple and uncomplicated design. This has been achieved by the device being given the features defined in the characterizing part of claim 1. DESCRIPTION OF THE DRAWINGS The invention will in the following be further described with reference to embodiments shown in the accompanying drawings. Figure 1 is a longitudional sectional view of a part of a steering wheel shaft according to the invention. Figures 2-4 are cross-sectional views taken along lines II-II, III-III and IV-IV resp. of figure 1. Figure 5 is a longitudional sectional view corresponding to figure 1 and showing another embodiment of a steering wheel shaft according to the invention. Figure 6 is a view in reduced scale of the steering wheel shaft housing of the steering wheel shaft according to figure 5 as seen in a section along line VI-VI. Figure 7 is a detail view of a steering wheel shaft according to the invention with a partly modified design. Figure 8 is another detail view of a further modification of a steering wheel shaft according to the invention. DESCRIPTION OF EMBODIMENTS Figures 1-4 illustrate different sections through a steering wheel shaft 1 according to the invention, which comprises a first steering column tube 2, a second tiltable steering column tube 3 and a steering wheel shaft housing 4 inter­ connecting the two steering column tubes. A steering wheel axle provided with a steering wheel and a steering axle cooperating with a steering mechanism interconnected by an angularly moveable connection, and rotatably housed in the two steering column tubes and the steering shaft housing, but these members are not shown in the drawings for entailing these a better clarity, as they are machine members well known per se and of conventional type. In the embodiment shown the first steering column tube 2 is longitudinally displaceable in the housing 4 and this displacement is limited by a shoulder 5 provided adjacent the end of the steering column tube, and arranged to move in a longitudinal groove 6 in the housing. The axial movement of the first steering column tube in the housing, therefore will be limited to the distance between the two ends of the groove, and rotation of the first steering column tube relative to the housing is furthermore prevented by cooperation between the shoulder 5 and the groove 6. In this particular embodiment the steering wheel shaft housing 4 - as can be best seen in figures 2 and 3 - is divided along an axial diametrical plane, and each half is equipped with a longitudional seat for the first steering column tube 2, when they are joined together by means of screws or the like. Around this seat and adjacent one end of the housing there is provided a circumferential groove 7, in which is inserted a thrust ring 8, which with some play surrounds the first steering column tube. By means of an actuating member 9, in the embodiment shown a ball, the thrust ring 8 can be exposed to a force acting radially from outside and thereby is capable of displacing the thrust ring 8 to lock the first steering column tube from axial displacement in relation to the housing 4. This locking function is known form SE-C- 8203018-0. In an elongated groove 10, arranged in the housing 4 along the seat for the first steering column tube but spaced apart from the same, a piston 11 is displaceably supported, said piston in the embodiment shown having a tapering portion 12 provided adjacent one end. Said piston 11 is by means of a spring 13 biased to press said tapering portion 12 against the actuating member 9 of the thrust ring, when the piston is not influenced by external forces, and thereby during displacement make the thrust ring 8 lock the first steering column tube 2 against axial displacement in relation to the housing. The piston 11 is provided with a recess 14 in which engages a control 15, which enables the piston to be displaced from the neutral position, against the effect of the spring 13, whereby the tapering portion 12 of the piston is displaced thus that the actuating member of the thrust ring - the ball 9 - during contact with the inclined surface of the taper, will be removed from the thrust ring 8, whereby said ring can be selfcentered around the first steering column tube 2, and thereby admit the displacement thereof in the housing. When the control is again relieved the spring 13 will return the piston to a position wherein the tapering portion 12 will press the ball 9 against the thrust ring 8, which will result in a locking of the motion of the first steering column tube. At the opposite end of the steering wheel shaft housing 4 of the present embodiment there is tiltably mounted a second steering column tube 3, forming part of the steering wheel shaft. For this purpose the housing is equipped with an internal cylindrical seat 16 having its center axis arranged perpendicularly to the longitudinal axis of the housing. The second steering column tube 3 at its end cooperating with the steering wheel shaft housing is provided with a hub 17 corresponding to the seat 16, which hub is pivotable in the seat. As shown in figures 1 and 4 a toothed segment 18 is provided on the hub, which toothed segment cooperates with a body 20 equipped with at least one catch 19, which body displays a through-hole and is moveably mounted on said piston 11. The body 20 is by a spring 21 biased against a position where the catch 19 and the toothed segment 18 engage into each other and thereby prevent rotation of the hub 17 in the seat 16. At displacement move of the piston 11 by means of the control 15 a shoulder 22 on the piston will press onto the body 20 and thereby displace the body against the action of the spring 21, whereby the catch 19 is brought out of engagement with the toothed segment 18 and thereby admits tiltings of said second steering column tube in relation to the main direction of the steering wheel shaft. As there in this embodiment is a small play between the shoulder 22 of piston and the body 20 in the neutral position of the piston, in the example shown a displacement of the piston by means of the control will result therein that the thrust ring 8 first will release the locking engagement with the first steering column tube, and at a further short displacement the adjustment of the second steering column tube will be released. If the play is eliminated both displacement will be released at the same time. Figure 5 and 6 show, in the view corresponding to figure 1 and a view from beneath mainly corresponding to figure 4 resp., a modified embodiment of a steering wheel shaft 1 according to the invention. Details having full correspondence in corresponding details in figure 1-4 are given the same references as these. This steering wheel shaft 1 thus includes a first steering column tube 2, a second steering column tube 3, a steering wheel shaft housing 4 with an internal seat for the first steering column tube, a groove 6 in which a shoulder 5 provided on the first steering column tube is restrictedly moveable. The axial motion of the first steering column tube in the housing can be locked by means of a thrust ring 8 loosely arranged in a groove 7 in the housing, whereby actuating members press against the thrust ring in a manner to displace said ring. The actuating members 23 in this case are formed by two cylindric rollers 23a, 23b, which in a seat are located one on each side of a tapering portion 12 on a piston 11 displaceably arranged in a groove in the housing, which piston is biased against a position where the tapering portion 12 is located thus that a first one 23a of the rolling bodies is pressed against the thrust ring and displaces the same, whereas the second rolling body 23b acts as a holder-on for the tapering portion in the seat. The seat is provided with a low friction material 29, against which said second rolling body 23b makes a short rolling movement at the displacement of the piston, whereby the starting friction at the beginning of the release movement is minimized, at the same time as the strength is increased. The axial displacement of the piston 11 is effected by a control 15 engaging into a recess 14 in the piston. At the opposite end of the housing 4 there is arranged a cylindrical seat 16 having its center axis arranged perpendicularly to the longitudinal direction of the steering wheel shaft. In this seat 16 is pivotably arranged a hub 17 located at the end of the second steering column tube 3, which hub in one side surface is provided with a toothed segment 24, which in this case projects from the hub and extends into a space where it cooperates with the catch formed by a catch lever 25 attached to a displaceable body 26, which is biased by a spring 27, thus that it uninfluenced by external forces holds the toothed segment 24 and the catch lever in interengagement thereby preventing the segment from pivoting. The body 26 is equipped with a stop 28 arranged to cooperate with the end of the piston 11 facing away from the tapering portion 12, whereby there is a play between said stop 28 and the piston 11, which means that a first part of the piston movement causes that the longitudinal adjustment of the first steering column tube adjustment relative to the steering wheel shaft house is made possible, whereas further displacement of the piston gives a possibility of tilting the second steering column tube relative to the steering wheel shaft housing . In this case the piston can be considered to consist of a two-part piston comprising the proper piston part 11 and the body 26. In figure 7 is shown a part of the piston 11 in enlarged scale and the actuating part for the thrust ring 8 is in this case designed as a recess 30 in the piston, which recess cooperates with an eccentrically supported body 31, which thus can re­ place the rolling elements in earlier illustrated embodiments. In figure 8 is illustrated how the piston can be divided in two piston parts 11a, 11b arranged in parallell positions, each serving one of the locking functions and each having an opening 14a and 14b resp. for the control 15. By giving each of these openings a play which are disposed on different sides of the working point of the control in its neutral position, is it easy to achieve an arbitrary displacement between the different releasing functions. The invention is not limited to the accompanying drawings and the embodiments described in connection thereto, but modifications are possible within the scope of the following claims. The steering column tubes shown in the examples can freely be turned so that either the first steering column tube, which is axially adjustable in relation to the housing, encloses the steering wheel shaft, which extends rotatably therethrough and cooperates with a not shown steering mechanism, whereas the second steering column tube, which is tiltable, encloses the rotatable steering axle with a steering wheel mounted thereon. The opposite condition is also possible, i.e. where the axially adjustable steering column tube is turned towards the steering wheel and the tiltable steering column tube is turned towards the steering mechanism. If there is a desire that the tilting movement is released before the longitudinal adjustment, this can be provided by allowing the actuating members 9,23 cooperate, e.g. with a straight part of the piston 11 before they come in contact with the tapering portion, whereas the play between the body 8 and the stop 29 is eliminated. It is also possible, in a corresponding manner, to arrange that both adjustment movements are relased at the same time. By moving the play within the area for the control cooperation with the piston and its cooperating parts, it is easily possible to bring about the release of the different locking functions in reversed order. The control has consistently in the drawings been shown as a hand operated lever 15, but the control can as well be consituted by a pedal, which transmits the power to the piston via a wire, or the piston itself can be formed as a machine element, which under influence of another external power source performs its displacement. In such a case the piston may e.g. be constituted by a part of an electromagnet, which at switching over upon an electric switch can be caused to move sufficiently for making the releasing or locking movements. In the drawings both the release and the locking functions have been demonstrated effected by axial displacement of the piston, but it is of course also possible, within the scope of the invention, to effect one or maybe both movements by rotating the piston.

Claims: 1. An adjustable steering wheel shaft for vehicles provided with means for adjustment of its length and means for adjustment of its inclination relative to the vehicle body, whereby the steering wheel shaft comprises a steering wheel shaft housing (4), a first steering column tube (2) displaceably arranged in said housing and a second steering column tube (3), pivotably arranged relative to said steering wheel shaft housing, said first and second steering column tubes (2,3) being interconnected by said intermediate steering wheel shaft housing (4), the said second steering column tube (3) at its end cooperating with the steering wheel shaft housing being provided with a hub (17), which is restrictedly rotatable in a set (16) in the steering wheel shaft housing around a pivot axle located perpendicularly to the longitudinal direction of the tube and being adapted be locked from rotation in a number of angular positions by means of a locking mechanism (18,19; 24,25), whereby the steering wheel axle and the steering axle are interconnected by an angularly adjustable coupling and extend through the said first and second steering column tubes and steering wheel shaft housing, and where a common control (15) is provided for releasing or locking the length adjustment and tilting movement of the steering wheel shaft resp.,characterized thereby, that at least one piston (11; 26; 11a,11b) is axially displaceable and/or pivotally supported in the housing, said piston being biased to a position in which it exertes a force locking said first steering column tube (2) against axial displacement and further brings the blocking mechanism (18,19; 24,25) to prevent the hub (17) from rotating around its pivot axle, whereby the piston by actuation of a control (15) is displaceably and/or pivotable to a first position in which it admits either axial displacement between said first steering column tube (2) and the housing (4) and/or admits the blocking mechanism (18,19; 24,25) to release the hub (17) thereby making possible rotation of said second steering column tube (3) in relation to the housing (4) or further to a second position wherein the other one of said motions is admitted, whereby two distinct, spaced apart release positions are obtained, one for easch one of said motions. 2. A steering wheel shaft as claimed in claim 1, where the axial displacement of said first steering column tube (2) in relation to the housing (4) is lockable by means of a thrust ring arranged in an angular groove (7) in the housing, and having a somewhat bigger inner diameter than the outer diameter of said axle, and which by radial actuation by a member (9;23a,23b;31), acting against the outer side of the thrust ring can be displaced in order to lock said axle from axial displacement,characterized thereby, that the piston (11,26;11a,11b) is provided with at least one actuation portion (12,30) adapted to cooperate with the actuation means (9,23a,23b,31) for the thrust ring (8), in order to alter the force exerted by the actuation means upon the thrust ring at displacement of the piston from neutral position, in which said piston is not influenced by the control. 3. A steering wheel shaft as claimed in claim 2,characterized therein, that the actuation means for the thrust ring is formed by at least one rolling body (9, 23a,23b) which is moveable in a seat and arranged to rest upon the actuation portion (12) of the piston and simultaneously to engage the thrust ring (8). 4. A steering wheel shaft as claimed in claim 3,characterized thereby, that the actuation means (23a,23b) incorporate at least two rolling bodies, at least one of which (23b) engages a surface portion (29) of low friction in the seat. 5. A steering wheel shaft as claimed in claim 2,characterized thereby, that the actuation means for the thrust ring is formed by at least one pivotally supported eccentric body (31) arranged to be actuated by the actuation portion (30) of the piston and to engage against the thrust ring (8) with a varying force in dependence of the instantaneous piston position. 6. A steering wheel shaft as claimed in anyone of the preceeding clams,characterized thereby, that the hub (17) is provided with a toothed segment (18,24) arranged to form a part of said blocking mechanism, while the other part of the mechanism is formed by a body (20,26) cooperating with the piston and being provided with a catch (19,25), said body being slideably arranged in a seat in the housing (4) and being biased towards a position in which the catch engages in said toothed segment thereby preventing the hub from rotating. 7. A steering wheel shaft as claimed in claim 6,characterized thereby, that the piston (11), at its end provided with the body (20) with the catch and/or that the body on the side facing the piston has shoulder (22 and 28 resp.) spaced apart from the body or the piston resp. when the piston is uninfluenced by external forces, and arranged at a first part of the displacement of the piston to be displaced to engagement against the body (20) or against the piston resp. and at further displacement of the piston to displace the body against its biasing force to a postion releasing the hub. 8. A steering wheel shaft as claimed in anyone of the preceeding claims,characterized thereby, that the first steering column tube (2) is displaceably arranged in the steering wheel shaft housing (4) between end positions determined by a lip (5) fitted to said shaft and moveable in a groove (6) in the steering wheel shaft housing between stops, which lip also prevents rotational movement between said steering column tubes and the housing. 9. A steering wheel shaft as claimed in any of the preceeding claims,characterized thereby, that the piston is divided into at least two parts (11,26) arranged in a groove one after the other with a mutual axial play. 10. A steering wheel shaft as claimed in anyone of claims 1-8, characterized thereby, that the piston is divided into two piston parts (11a,11b) moveable in parallel positions, the actuation motions of the control being transmitted to said piston parts via points of action having different play (14a,14b).

Inventors: ANDERSSON, OLLE
Applicants: VERKSTADS AB CLAES JOHANSSON
Application year: 1986
Main classification: B62D1
IPC codes: B62D1