TILT-TELESCOPE STEERING COLUMN

Abstract: A steering column (12) has a pair of steering column members (22, 24) arranged coaxially about a first axis (A). One of the steering column members (22) is axially movable along the first axis relative to the other steering column member (24). The steering column members are supported for angular movement about a second axis (6) extending transverse to the first axis (A). A first lock (16) releasably locks the members in one of a plurality of relative axial positions along the first axis. A second lock (14) releasably locks the members in one of a plurality of angular positions about the second axis. A control lever (18) is mounted for pivotal movement toward and away from a neutral position. An actuator (140, 142) operates in response to pivotal movement of the control lever (18) away from the neutral position in a direction of desired movement of the one member (22) to actuate one or both of the first and second locks to release the one member (22) for movement to the desired position.

Description: The present invention relates to a steering column for a vehicle, and particularly, relates to a steering column which is axially and angularly adjustable. A vehicle steering column apparatus known for example from US-A-3386309 or US-A-4649769 comprises: a pair of steering column members arranged coaxially about a first axis, one of said members being movable axially along the first axis relative the other of said members; said members being supported for angular movement about a second axis extending transverse to the first axis; a first lock for releasably locking said members in one of a plurality of relative axial positions along the first axis; a second lock for releasably locking said members in one of a plurality of angular positions about the second axis; a control lever mounted for pivotal movement toward and away from a neutral position; and an actuating mechanism connected with said first and second locks and operable in response to pivotal movement of said control lever away from said neutral position for actuating said first or second locks to release said members respectively for movement of said one member between relative axial positions along the first axis, or for movement of both members between angular positions about the second axis. In these known apparatuses, the control lever is pivotably movable in arbitrary directions which do not correspond to the desired movement of the steering column members between their axial or angular positions. In order to ensure that a pivotal movement of the control lever in a desired direction will result in a movement of the steering column members in the same direction, the present invention provides that the actuating mechanism is responsive to pivotal movement of said control lever away from said neutral position in a direction of desired movement of said one member for actuating one or both of said locks to release said one member for movement in the same direction as the direction in which said control lever is moved. According to the invention, the actuating mechanism includes a first actuator operable in response to pivotal movement of the control lever away from the neutral position in either direction in a first plane extending through the central axis to release the telescope lock mechanism permitting the members to move axially relative to each other. The actuating mechanism includes a second actuator operable in response to movement of the control lever away from the neutral position in either direction in a second plane extending perpendicular to the central axis to release the tilt lock mechanism permitting the members to move angularly. Furthermore, the first actuator and second actuator are operable together in response to movement of the control lever away from the neutral position in a direction diagonally between the first and second planes to release both the telescope and tilt lock mechanisms permitting simultaneous telescoping and tilting. Brief Description of the Drawings Further features and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from reading the following specification with reference to the accompanying drawings, in which: Fig. 1 is a sectional view of a steering column embodying the present invention; Fig. 2 is a side elevational view of the steering column of Fig. 1, taken approximately along the line 2-2 of Fig. 1; Fig. 3 is an enlarged sectional view of a portion of the steering column of Fig. 1; Fig. 4 is an enlarged elevational view taken approximately along the line 4-4 of Fig. 3; Fig. 5 is a sectional view taken approximately along the line 5-5 of Fig. 3; Fig. 6 is a sectional view taken approximately along the line 6-6 of Fig. 3; Fig. 7 is an elevational view of a portion of the tilt lock mechanism of Fig. 4 with the parts illustrated in another position; and Fig. 8 is a schematic view of a control lever, taken approximately along the line 8-8 of Fig. 3, illustrating its possible paths of movement. Description of a Preferred Embodiment A tilt-telescope steering column 12 embodying the present invention is shown in Fig. 1. The steering column 12 is angularly adjustable (tilts) and axially adjustable (telescopes). The steering column 12 includes a tilt locking mechanism 14, a telescope locking mechanism 16, a control lever 18 and an actuator mechanism 20. The actuator mechanism 20 is operable to release one or both of the tilt locking mechanism 14 and telescope locking mechanism 16 in response to movement of the control lever 18 away from a neutral or initial position. The steering column 12 includes a pair of steering column members 22, 24. The upper steering column member 22 axially moves or telescopes relative to the lower or outer steering column member 24 to effect axial adjustment of the steering column 12 along the longitudinal central axis A of the steering column members. The steering column members 22, 24 move angularly or tilt about a tilt axis B to effect angular adjustment of the steering column 12. The axis B is perpendicular to the axis A. The steering column member 22 includes an upper shaft 32 and an upper tubular member 34. The upper tubular member 34 of the column member 22 houses a bearing 36 which supports the upper shaft 32 for rotation about the axis A. The vehicle steering wheel (not shown) is connected to the upper shaft member 32, as is known, and is thus connected to the upper steering column member 22. The upper shaft member 32 rotates about the axis A upon rotation of the vehicle steering wheel. The steering column member 24 includes a lower shaft 42 and a lower tubular member 44. The lower shaft 42 receives a portion of the upper shaft 32. The lower shaft 42 has internal splines 46a which mesh with external splines 46b on the upper shaft 32. Thus, rotational force between the shafts 32, 42 is transmitted through the splines 46a, 46b. The lower tubular member 44 is supported for pivotal movement relative to a mounting 50 by fasteners 52. The mounting 50 attaches the steering column 12 to the vehicle. The lower tubular member 44 axially receives a portion of the upper tubular member 34. The upper tubular member 34 is axially movable relative to the lower tubular member 44 along the axis A. The tubular members 34, 44, and thus the steering column members 22, 24, are coaxially arranged for relative telescoping movement and are supported by the mounting 50 for tilting movement about the axis B. The lower shaft 42 is connected to a yoke 54 of a universal joint 56. The universal joint 56 is also connected to an output shaft 58 attached to the steering gear (not shown) of the vehicle. The output shaft 58 is journalled in bearings 62 supported by plates 64 connected with the mounting 50. The universal joint 56 has a pivot axis about which the lower shaft 42 may pivot which is coaxial with the tilt axis B. Thus, upon rotation of the steering wheel, steering force is transmitted through the shafts 32, 42 to the output shaft 58 to effect vehicle steering. The tilt locking mechanism 14 (Figs. 2 and 3) releasably locks the steering column members 22, 24 in one of a plurality of tilt positions about the axis B relative to a mounting 50. The tilt lock mechanism 14 (Fig. 4) includes a fixed plate 72 and a movable plate 74. The fixed plate 72 is attached to the mounting 50. The fixed plate 72 has a plurality of teeth 82 formed along its outer periphery. The movable plate 74 is elongated and slidable within an elongated slot 76 extending in a direction parallel to the longitudinal axis A in the lower tubular member 44. The movable plate 74 also has a plurality of teeth 84 extending axially from an end which teeth 84 mesh with the teeth 82 of the fixed plate 72 to lock the fixed plate and movable plate together. A pin 86 is fixed to the lower tubular member 44 and is snugly received in a slot 88 in the movable plate 74 to guide axial movement of the plate between opposite lock and release positions toward and away from the fixed plate 72. A pair of springs 92 are disposed at an end of the movable plate 74 axially opposite from the teeth 84. The springs 92 bias the movable plate 74 toward the fixed plate 72 to cause meshing of the teeth 82, 84 to normally lock the plates together and maintain the steering column members in a tilt position. The telescope locking mechanism 16 releasably locks the steering column members 22, 24 in one of a plurality of relative axial or telescoped positions along the axis A. The telescope lock mechanism 16 (Fig. 3) includes a locking pin 94 received in a bearing 96 mounted in the lower tubular member 44 and a plurality of axially spaced openings 98 in a portion of the upper tubular member 42. A housing 102 is connected to the lower tubular member 44. A spring 100 acts between the housing 102 and the end of the locking pin 94 to bias the locking pin into one of the openings 98. When the locking pin 94 is in any one of the openings 98, the steering column member 22 is prevented from telescoping relative to the steering column member 24. When the locking pin 94 is withdrawn from the openings 98, the steering column members 22, 24 are released and may telescope relative to one another to axially adjust the steering column 12. A slot 104 is in the movable plate 74 to permit the locking pin 94 to pass through. The slot 104 is sized such that the locking pin 94 does not interfere with the sliding movement of the movable plate 74, nor does sliding movement of the movable plate interfere with movement of the locking pin 94. The control lever 18 includes an elongated shaft 110 having a handle grip 112 attached to an axial end portion of the shaft. A spherical bearing 120 is mounted to the other axial end portion of the shaft 110. A hemispherical member 122 is spaced a short distance from the bearing 120 along the shaft 110. A bearing 132 having a recess shaped similar to the hemispherical member 122 is mounted in the housing 102. The bearing 132 receives the hemispherical member 122 to support the control lever 18 for pivotal movement relative to the housing 102. A compression spring 134 is disposed between the housing 102 and a planar surface portion 136 of the hemispherical member 122. The spring 134 applies a biasing force urging the control lever 18 to a neutral position, as illustrated in Figs. 1 and 3. The actuating mechanism 20 includes a tilt actuator 140 (Fig. 4) and a telescope actuator 142 (Fig. 3). The tilt actuator 140 is operable in response to movement of the control lever 18 away from the neutral position to release the tilt lock mechanism 14. The control lever 18 is movable in either direction in a plane extending transverse to the axis A, such as in the directions C-D, as illustrated in Fig. 8, to release the steering column members 22, 24 from being locked in one of the tilt positions. The telescope actuator 142 is operable in response to movement of the control lever 18 away from the neutral position to release the telescope lock mechanism 16. The control lever 18 is movable in either direction in a plane extending along the longitudinal axis A, such as in the directions E-F, to release the steering column members 22, 24 from being locked in a telescoped position. Both the tilt actuator 140 and telescope actuator 142 are operable together upon movement of the control lever 18 away from the neutral position to simultaneously release both the tilt and telescope locking mechanisms 14, 16. The control lever 18 is movable from the neutral position diagonally between the plane extending through axis A and the plane extending transverse to the axis A, such as in the directions G-H and I-J to release the steering column members 22, 24 to simultaneously tilt and telescope. Thus, when the control lever 18 is moved from the neutral position, the steering wheel and upper steering column member 22 may move in the same direction as control lever movement. The telescope actuator 142 is preferably a metal plate member 150 (Figs. 3 and 5) A central bearing 152 is connected to the plate member 150. The bearing 152 has a surface defining a spherical cavity 154. The bearing 152 retains the spherical bearing 120 in the spherical cavity 154 for moving the plate member 150 in response to pivotal movement of the control lever 18 about the hemispherical member 122. A pair of spaced apart flanges 156 extend in the same direction from opposite lateral sides of the plate member 150. A cam portion 160 (Fig. 3) in the form of an arcuate depression in the plate member 150 extends between the flanges 156 and is spaced from the bearing 152. A roller 162 (Figs. 3 and 6) connected to the locking pin 94 of the telescope locking mechanism 16 is normally engaged with and seated in the cam portion 160 of the plate member 150. The forward or tapered end portion of the locking pin 94 extends into one of the openings 98 to lock the steering column members 22, 24 in a given telescoped position. The plate member 150 is slidable on a pair of spaced apart bars 164 extending transversely across the housing 102. The bars 164 extend through slots 202 in the flanges 156. The plate member 150 is movable parallel to the axis A, transverse to the axis A, and diagonally therebetween corresponding to the directions C through J of the control lever 18, as seen in Fig. 8. The plate member 150 actually moves in a direction opposite to the direction of movement of the control lever 18 because the control lever pivots about the hemispherical bearing 122 intermediate the plate member and handle grip 112 which the operator moves. When the plate member 150 is moved in a direction parallel to the axis A or diagonally thereto, the roller 162 rides along a side surface of the cam portion 160. The locking pin 94 is forced out of the opening 98 by the roller 162 to release the telescope locking mechanism 16 and permit telescoping of the steering column 12. The steering column member 22 is lightly biased by the spring 170 towards the extended position relative to the steering column member 24. Thus, when the telescope locking mechanism 16 is released, the steering column 12 will tend to extend due to the bias force. The bias force can easily be overcome by the vehicle operator moving the control lever in the direction F (Fig. 8) to contract the steering column 12. When the plate member 150 moves transversely to the axis A, the roller 162 merely slides along the depression of the cam portion 160 without pulling the locking pin 94 to actuate the telescope lock mechanism 16. The tilt actuator 140 (Fig. 4) includes a contractable and extendable scissor linkage mechanism 190 disposed between and engageable with the flanges 156 of the plate member 150. A scissor linkage mechanism 190 is pivotally supported at one end 192 about the bearing 96 connected to the lower tubular member 44. The scissor linkage mechanism 190 is also pivotally connected at an opposite end portion 194 to the movable plate 74 of the tilt locking mechanism 14. When the plate member 150 of the telescope actuator 142 is moved transversely to the axis A from the neutral position illustrated in Fig. 4, one of the flanges 156 engages a respective side of the scissor linkage mechanism 190. The flange 156 forces the scissor linkage mechanism 190 to move from the longitudinally contracted position to the longitudinally extended position illustrated in Fig. 7. The scissor linkage mechanism 190 laterally contracts as it longitudinally extends. The end portion 194 of the scissor linkage mechanism 190 moves in a direction parallel to the axis A as the scissor linkage mechanism extends to move the movable plate 74 away from the fixed plate 72. Thus, the tilt locking mechanism 14 is actuated by moving the teeth 84 of the movable plate 74 out of engagement with the teeth 82 on the fixed plate 72 to release the steering column 12 to tilt. The steering column 12 is lightly biased by the spring 198 to pivot counterclockwise about the tilt axis B, as viewed in Fig. 2, when the tilt lock mechanism 14 is actuated. However, the bias can be easily overcome by the vehicle operator moving the control lever 18 in the direction D (Fig. 8) to pivot the steering column 12 clockwise about the axis B. When the plate member 150 is moved in a direction diagonal to the axis A, such as in the directions G, H, I or J (Fig. 8), the roller 162 is forced along a side surface of the cam portion 160 and simultaneously one of the flanges 156 engages the scissor linkage mechanism 190. The locking pin 94 is pulled from one of the openings 98 by the roller 162. The movable plate 74 is pulled out of locking engagement with the fixed plate 72 by the scissor linkage mechanism 190. Thus, the tilt locking mechanism 14 and the telescope locking mechanism 16 are released simultaneously to permit both tilting and telescoping of the steering column 12. The resistive force of the springs 92, 100 of the telescope and tilt lock mechanism 16, 14 will transmit a "feedback" signal through the control lever 18 to the vehicle operator. For example, moving the control lever 18 in the direction D (Fig. 8) will tilt the steering column 12 only clockwise, as viewed in Fig. 2, about the axis B and the control lever will transmit a resistive force to the operator due to the bias of the springs 92. Moving the control lever 18 in direction J will tilt the steering column 12 clockwise and extend it, but will transmit a resistive force approximately twice that of movement of the control lever for just tilting or telescoping. Thus, the steering column 12 will have a natural tendency to keep the control lever 18 in a mode that releases only one of the two lock mechanisms 14, 16 at a time. If an operator wants to release both at one time, he can do so but the control lever 18 will have a relatively larger resistive force. Although the control lever 18 is movable in any direction from its neutral position, as seen in Fig. 8, if so desired it can be restricted by mechanically blocking movement in the directions G, H, I, and J so the operator can only release one of the locking mechanisms 14, 16 at a time.

Claims: 1. A vehicle steering column apparatus comprising: a pair of steering column members (22, 24) arranged coaxially about a first axis (A), one of said members (22) being movable axially along the first axis (A) relative the other (24) of said members; said members being supported for angular movement about a second axis (B) extending transverse to the first axis (A); a first lock (16) for releasably locking said members (22, 24) in one of a plurality of relative axial positions along the first axis (A); a second lock (14) for releasably locking said members (22, 24) in one of a plurality of angular positions about the second axis (B); a control lever (18) mounted for pivotal movement toward and away from a neutral position; an actuating mechanism (20) connected with said first and second locks (16, 14) and operable in response to pivotal movement of said control lever (18) away from said neutral position for actuating said first (16) or second (14) locks to release said members (22, 24) respectively for movement of said one member (22) between relative axial positions along the first axis (A), or for movement of both members between angular positions about the second axis (B), characterized in that said actuating mechanism (20) is responsive to pivotal movement of said control lever (18) away from said neutral position in a direction of desired movement of said one member (22) for actuating one or both of said locks (16, 14) to release said one member (22) for movement in the same direction as the direction in which said control lever (18) is moved. 2. The apparatus as set forth in claim 1, wherein said actuating means (20) includes telescope actuating means (142) operable in response to pivotal movement of said control lever (18) away from said neutral position in a plane containing the first axis (A) for actuating said first lock (16) to release said one member (22) and permit movement thereof along the first axis (A) relative to the other member (24), and wherein said actuating means (20) includes tilt actuating means (140) operable in response to pivotal movement of said control lever (18) away from said neutral position in a plane extending transverse to the first axis (A) for actuating said second lock (14) to release said members (22, 24) and permit movement thereof angularly about the second axis (B). 3. The apparatus as set forth in claim 2, wherein said telescope actuating means (142) and said tilt actuating means (140) are operable in response to pivotal movement of said control lever (18) away from said neutral position in a direction diagonally between said plane containing the first axis (A) and said plane extending transverse thereto for actuating both said first and second locks (16, 14) to release said one member (22) and permit movement thereof along the first axis (A) relative to the other member (24) and to release said members (22, 24) and permit movement thereof angularly about the second axis (B). 4. The apparatus as set forth in either claim 2 or 3, and further comprising a housing (102) connected to said second member (24), said first lock (16), said second lock (14) and said lever (18) being mounted to said housing (102). 5. The apparatus as set forth in anyone of claims 2 to 4, wherein said control lever (18) includes: an elongated shaft (110); a spherical bearing (120) disposed adjacent an end portion of said shaft (110) and connected to said actuating means (20) for pivotal movement relative thereto; a hemispherical member (122) disposed on said shaft (110) axially spaced from said spherical bearing (120) for mounting said shaft (110) to one of the steering column members (22, 24) for pivotal movement relative thereto; and biasing means (134) engaged with a planar surface portion (136) of said hemispherical member (122) for applying a biasing force to urge said shaft (110) to said neutral position. 6. The apparatus as set forth in claim 5, wherein said telescope actuating means (142) comprise a plate member (150) pivotally connected to said spherical bearing (120), a pair of spaced apart flange portions (156) extending in the same direction from said plate member (150), and a cam portion (160) extending between said flange portions (156) for engaging first lock (16), said plate member (150) being slidable along said first axis (A) upon pivotal movement of said control lever shaft (110) for said cam portion (160) to actuate said first lock (16). 7. The apparatus as set forth in claim 6, wherein said tilt actuating means (140) comprise a contractable and extendable scissor linkage mechanism (190) disposed between and engageable with said flange portions (156) of said plate member (150), said scissor linkage mechanism (190) being pivotally supported at one end (192) by one of the steering column members (22, 24) and pivotally connected at an opposite end (194) to said second lock (14), said scissor linkage mechanism being extendable to actuate said second lock (14) upon engagement with one of said flange portions (156) of said plate member (150) in response to pivotal movement of said control lever shaft (110) in a direction transverse to said first axis (A).

Inventors: SHROPSHIRE, DAVID C., VENABLE, FREDRICK D.
Applicants: TRW INC.
Application year: 1988
Main classification: B62D1
IPC codes: B62D1