WO2010151259A1

WO2010151259A1 - Vehicle seat assembly

Info

Publication number: WO2010151259A1
Application number: PCT/US2009/048605
Authority: WO
Inventors: Stanislaw Andrzej Wieclawski
Original assignee: Lear Corp
Current assignee: Lear Corp
Priority date: 2009-06-25
Filing date: 2009-06-25
Publication date: 2010-12-29
Anticipated expiration: 2011-12-25

Abstract

A seat assembly includes a back frame rotatably attached to a seat pan and movable between an upright position and a dumped forward position. The seat assembly is mounted on a secured track through an adjustment track mounted to the seat pan. A locking mechanism selectively locks the adjustment track to the secured track. A memory mechanism engaged with the secured track can be used to reposition the seat assembly in the position it was in immediately prior to folding of the seat back to a dumped forward position. The locking mechanism includes means for positioning the memory mechanism along the secured track when the seat back is in an upright position. The positioning means is disengaged from the locking mechanism when the seat back is in a dumped forward position so that the memory mechanism maintains its position with the secured track.

Description

VEHICLE SEAT ASSEMBLY

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to vehicle seat assemblies and more particularly to seat assemblies with position memory.

[0002] Typical vehicle seat assemblies provide for a seat to be moved or adjusted along a track in the forward and rearward directions. In many vehicles, it is desirable to have "easy entry" seats in which the seat back is rotated to a forward position and the seat assembly moved to a forward position for easier access to rear seating or compartments behind the seat. This feature is beneficial in two-door automotive designs wherein access to both the forward seating as well as the rear seating is provided by way of entry through a single door. In these designs, when the seat back is rotated forward past a typical upright position for accommodating a passenger, it is said to be in a "dumped forward" position.

[0003] On disadvantage of such easy entry designs is that repeated adjustments may be required to return the seat to its original position. To alleviate this problem, designs with position memory have been used. Some designs provide for easy return of the seat to a default position, such as a mid-point position between the full forward and full rearward position. Other designs allow the seat to be returned to the last seat position, but these are generally more complex and expensive. SUMMARY OF THE INVENTION

[0004] The present invention is a seat assembly which includes a seat pan and a back frame rotatably attached to the seat pan and movable between an upright position and a dumped forward position. The seat assembly is mounted on a secured track through an adjustment track mounted to the seat pan. A locking mechanism connected to the adjustment track is movable between a locked position in which the secured track and adjustment track are secured together and an unlocked position in which the adjustment track is free to move relative to the secured track.

[0005] The seat assembly includes a memory mechanism for positioning the adjustment track relative to the secured track in the last position prior to movement of the seat back to a dumped forward position. The memory mechanism remains engaged with the secured track when the back frame is in a dumped forward position but may be disengaging from the secured track when the back frame is a position other than a dumped forward position.

[0006] Preferably, the memory mechanism is mounted on and selectively movable relative to a guide member mounted on the secured track, and the locking mechanism includes means for positioning the memory mechanism when the seat back is in an upright position which can be disengaged when the seat back is in a dumped forward position.

BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG. 1 is a schematic of a vehicle seat assembly in accordance with the present invention.

[0008] FIG. 2 is an exploded view of the various components of the seat track assembly in accordance with the present invention.

[0009] FIG. 2A is a perspective view of the seat track assembly in accordance with the present invention.

[0010] FIG. 2B is a partially cut-away perspective view of the seat track assembly in accordance with the present invention.

[0011] FIGS. 3 and 4 are perspective views of portions of the locking and memory mechanisms of FIG. 2B.

[0012] FIGS. 5, 5 A, 6, and 6A are perspective views of portions of the locking and memory mechanisms of FIG. 2B.

[0013] FIGS. 7-9 are views of various positions of the locking and memory mechanisms of FIG. 2B.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0014] Referring to FIG. 1, automotive easy-entry seat assembly 10 includes a seat pan 12 and a back frame 14. The back frame 14 is rotatably attached to the seat pan 12 such that it can be moved between a generally upright position as shown and a dumped forward position (not shown). For some vehicle designs, the back frame 14 may be rotatable to a fully reclined position opposite of a dumped forward position. [0015] The back frame 14 may be operated in a variety of ways. One method employs a back frame release lever 20 connected to one or more back frame locking mechanisms 22 by release cables 24. Through activation of the back frame release lever 20, the back frame locking mechanisms 22 can be disengaged and the back frame 14 can be rotated about a pair of back frame joints 26 connecting the back frame 14 to the seat pan 12. A wide variety of back frame locking mechanisms is known in the art and may be used with the present invention.

[0016] Referring in addition to FIGS. 2, 2A and 2B, seat assembly 10 further includes two secured tracks 28 intended for mounting to a vehicle (not shown) by any well known method, such as by bolts extending through slots 30 to the vehicle floor or frame. Each secured track 28 includes detents in the form of slots 42 along its length for engagement with trigger teeth as will be described.

[0017] Two adjustment tracks 36 are mounted to the seat pan 12 by nuts (not shown) and bolts 37. A one-piece plastic roller mount 31 accommodates relative movement of one of the adjustment tracks 36 with a corresponding secured track 28, while a two-piece metal roller mount 32 serves the same purpose for the opposite tracks. Roller mount 32 is made with two pieces to accommodate movement of a memory mechanism as will be described. Roller mounts 31, 32 include roller and ball bearings for easy movement of the adjustment tracks 36 relative to the secured tracks 28. This movement allows the seat pan 12 and the back frame 14 to slide into a variety of positions along the secured tracks 28.

[0018] A seat locking mechanism includes a towel bar 41 rigidly fixed to a pair of adjustment bars 48. The locking mechanism also includes triggers 46 and 46'. Adjustment bars 48 and triggers 46, 46' are pivotally attached to guides 43 by pins 49' and 47' extending though apertures 49 and 47, respectively. Each guide 43 is attached to an adjustment track 36. Adjustment bars 48 and triggers 46, 46' are biased by a springs 45 as is well known in the art.

[0019] Referring to FIGS. 3 and 4, each trigger 46, 46' has teeth 44 adapted to engage detents, the slots 42, in the associated secured track 28 to secure the seat assembly to the secured track. The adjustment tracks 36, and therefore the seat assembly, can be secured in a variety of longitudinal positions along the secured tracks 28 by positioning one or more engagement teeth 44 within a group of engagement slots 42.

[0020] Normal passenger seat adjustment is accomplished by raising the towel bar 41 and adjustment bars 48, which pivots triggers 46, 46' about pins in apertures 47 from an engagement position wherein one or more engagement teeth 44 are positioned within one or more engagement slots 42, to a travel position wherein the adjustment tracks 36 are free to move longitudinally along the secured tracks as is well known in the art.

[0021] A torsion bar 130 is rotatably mounted on brackets 133 which are mounted on each adjustment track 36. The torsion bar is used to disengage triggers 46, 46' when the seat back 14 is rotated to a forward position as is well known in the art.

[0022] Referring to Fig. 4, a memory mechanism 50 is located on the master side of adjusting track 36. The memory mechanism 50 can be located on either adjusting track, i.e. on either side of the associated seat seat. As is more clearly seen in FIG. 6, the master side trigger 46 includes a U-shaped downwardly extending slot 93 defined in part by a drag tab 94 for selective moving of the memory mechanism as will be described. [0023] The memory mechanism 50 includes a memory block 52 and a hook plate 90 made of two identical plates (FIG. 5) spaced apart and rigidly secured together by C-shaped pins 102, 104, and 108 extending through aligned apertures in the spaced plates. Trigger 46 is pivotally attached to the hook plate 90 through pin 102. Trigger 46 also defines a spring opening 105 (FIG. 6) which houses a spring 106 which fits within and acts against hook plate pin 104 to return the trigger 46 to a desired position as will be described.

[0024] Referring to FIGS. 5, 5A and 6, memory mechanism 50 further includes a memory stopper 54 pivotally attached to the memory block 52 by a pin 56. The memory stopper 54 includes a slot having an upper surface 62 for resting on a memory stopper support portion 55, and a tooth 64 for engaging one of the secured track slots 42. The memory block 52 has grooves 52' (FIG. 2B) for slidably engaging the C-channel 53 (see FIGS. 2 and 4) which is attached to secured track 28. The channel 53 has a central longitudinal slot 57 extending substantially its entire length to allow the memory stopper tooth 64 to access the secured track slots 42.

[0025] The memory stopper 54 further includes an extension 66 extending oppositely from the tooth 64 with a transversely extending boss 68 for engaging the hook plate lift tab 92 in appropriate circumstances as will be described. The boss may be integrally formed with the memory stopper, or may be in the form of a pin attached to the memory stopper. A coil spring 70 is positioned around the memory stopper pin 56. The spring 70 has a pair of legs 72 secured to the memory block 52 and another leg in the form of a loop 74 which biases the memory stopper 54 toward an engaged position, i.e. biases the memory stopper tooth 64 toward secured track guide slots 42. Alternatively, the coil spring 70 could bear against the secured track 28 or the memory block channel 53. For example, the legs 72 could be in sliding engagement with the channel 53 to bias the memory stopper toward the engaged position.

[0026] It is preferred that the spring 70 exerts no force on the memory block or the memory stopper when the mechanism is in the engaged position as shown in FIG. 5A, i.e. with tooth 64 extending into a slot 42 and the memory stopper surface 62 supported by support surface 55. In other words, the coil spring 70 will bias the memory stopper only when it begins to move from the engaged position.

[0027] Referring to FIGS. 6, and 6 A, actuator torsion bar 130 extends between and is mounted on adjustment tracks 36 by brackets 133. Plastic bushings 135 allow easy rotation of the actuator bar in the bracket apertures. A cable link 132 is welded adjacent one end.

[0028] A lift link 58 is welded to the torsion bar 130 on the side of adjacent bracket 133 opposite the cable link 132. The lift link operates to isolate the memory stopper 54 from the hook plate 90 as will be described. The end of the lift link 58 opposite the end attached to torsion bar 130 engages the hook plate pin 108. Rotation of the lift link 140 causes rotation of the hook plate 90 about pin 102 such that the hook plate lift tab 92 swings out from underneath the memory stopper pin 68, whereby subsequent lifting of the trigger 46 and memory the hook plate 90 does not disturb the position of the memory block 52.

Normal Seat Position Adjustment

[0029] The normal seat locked position of the locking device is shown in FIG. 2B with both the trigger 46 and the memory stopper 54 engaged with the secured track 28, thereby preventing longitudinal movement of the adjustment tracks relative to the secured tracks. From the normal locked position, raising or pivoting the towel bar 41 and adjustment bars 48 causes a reverse pivot of the triggers 46, 46' and withdrawal of the teeth 44 from the secured track slots 42. The hook plate 90 is pivotally connected to the trigger 46 through pin 102. However, pivoting of the trigger 46 to cause withdrawal of the teeth 44 from the slots 42 does not cause relative rotation of the hook plate 90. Rather, the hook plate 90 maintains its position with the hook plate lift tab 92 positioned underneath the memory stopper pin 68. As a result, the memory stopper 54 is raised and the memory stopper tooth 64 is withdrawn from the secured track slot 42 in which it rested, as shown in FIG. 7. During normal seat adjustment, trigger drag slot 93 defined in part by drag tab 94 engages the memory stopper boss 68 to push or pull the memory mechanism 50 longitudinally forward or rearward to a position corresponding to that of the trigger 46.

Dump Forward Position

[0030] When the back frame 14 is folded or rotated forward, the cable assembly 139 rotates the torsion bar 130 to lift the triggers 46, 46' and the corresponding locking teeth 42 from the secured track slots 42 as is well known in the art, allowing the seat assembly freedom to travel longitudinally. Seat assembly travel is generally gravity biased to a forward location. Rearward movement is prevented by the memory block 52 as will be described.

[0031] A folding forward of the back frame rotates the bar 130 and the lift link 58 to the position shown in FIG. 8. Folding or rotation of the back frame 14 first causes the lift link 58 to rotate the hook plate 90 around pin 102, swinging the hook plate lift tab 92 out from underneath the stopper boss 68 against the force of spring 106. Rotation of folding of eth back frame 14 subsequently causes a lifting of the trigger 46 and the hook plate 90. The subsequent movement will not disturb the position of the memory stopper 54. The seat assembly can then moved forward along the secured track 28 while the memory mechanism remains in position engaged with the secured track.

Return from the Dumped Forward Position

[0032] When the back frame 14 is in a dumped forward position, the triggers 46, 46' are raised from the secured tracks 28 and the seat assembly is free to move forward along the track to its forward most position. Referring to FIG. 9, when the seat assembly is retuned from a forward position with the seat back in a dumped forward position, trigger 46 will move rearward along secured track 28. If the trigger 46 is moved far enough, the rearward surface 120 of the hook plate 90 will engage the forward surface 122 of the memory stopper 54. The memory block 52 is anchored to the secured track 28 by the memory stopper tooth 64 which is engaged with the secured track slots 42 and therefore will not be moved by the force of trigger 46. Instead, the engagement of surfaces 120 and 122 will force a reverse pivot of the hook plate 90 around pin 102 to a position similar to that of FIG. 8. Further rearward movement of the trigger 46 will cause a trigger surface 95 to engage the memory stopper surface 122 which will prevent any further rearward movement of the seat assembly.

[0033] Rotation of the hook plate 90 rotates the lift link 58 and the torsion bar 130, releasing the tension on the cable assembly 139 between the back frame 14 and the torsion bar 130. A spring assembly 137 (FIG. 6A), which is part of the cable assembly 139, biases the torsion bar 130 to allow springs 45 to bias the triggers 46, 46' to drop and the trigger teeth 44 to reengage the secured track slots 42 at the same location as prior to the forward dump. After the triggers 46, 46' drop into engagement with the secured track, the springs 138 and 106 will rotate the hook plate 90 such that the lift tab 92 swings back under the memory stopper pin 68. Therefore the hook plate 90 will be in position to lift and push or pull the memory block 52 if the next move is a normal seat adjustment.

Safety Lock Feature

[0034] If, after moving the seat back to a dumped forward position, the seat assembly is not returned all the way back to the position it was in immediately prior to moving to the dumped forward position as marked by the memory block, the triggers 46, 46' will nevertheless be able to lock the seat assembly in any selected position forward of the memory mechanism. This is a safety feature to assure that the seat may always be in a locked position. Of course, the memory block will only mark the position it was in prior to repositioning the seat at a location forward of the memory block.

[0035] The preferred embodiment described herein is merely illustrative of the principles of the invention. Numerous modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

What is claimed is:

1. A vehicle seat assembly comprising: a seat pan; a back frame rotatably attached to the seat pan and rotatable between a generally upright position and a dumped forward position; a secured track attachable to a vehicle; an adjustment track movable with respect to the secured track and configured to support the seat pan such that the seat pan is movable with the adjustment track; a locking mechanism connected to the adjustment track and movable between a locked position wherein the secured track and adjustment track are secured together and an unlocked position wherein the adjustment track is free to move relative to the secured track; and a memory mechanism for positioning the adjustment track relative to the secured track, the memory mechanism including means for engaging the secured track; wherein the memory mechanism is engaged with the secured track when the back frame is in a dumped forward position and the locking mechanism is in the unlocked position, and wherein the memory mechanism is disengaging from the secured track when the back frame is in a position other than a dumped forward position and the locking mechanism is in the unlocked position.

2. A vehicle seat assembly comprising: a seat pan; a back frame rotatably attached to the seat pan and rotatable between a generally upright position and a dumped forward position; a secured track attachable to a vehicle; an adjustment track movable with respect to the secured track and configured to support the seat pan such that the seat pan is movable with the adjustment track; a locking mechanism connected to the adjustment track and movable between a locked position wherein the secured track and adjustment track are secured together and an unlocked position wherein the adjustment track is free to move relative to the secured track; a memory mechanism for positioning the adjustment track relative to the secured track; and a guide member mounted on the secured track, the memory mechanism mounted on and selectively movable relative to the guide member; wherein the memory mechanism includes means for maintaining the memory mechanism position relative to the secured track when the back frame is in a dumped forward position and for disengaging from the secured track when the back frame is a position other than a dumped forward position.

3. A vehicle seat assembly as defined in Claim 2, wherein the memory mechanism includes means for engaging the secured track.

4. A vehicle seat assembly as defined in Claim 3, wherein the secured track includes detents for engagement by the locking mechanism and the guide member is includes an opening for allowing access of the memory member to the detents.

5. A vehicle seat assembly as defined in Claim 4, wherein the memory mechanism includes a tooth for engaging the secured track, and wherein the secured track detents comprise slots for accepting the tooth.

6. A vehicle seat assembly comprising: a seat pan; a back frame rotatably attached to the seat pan and rotatable between a generally upright position and a dumped forward position; a secured track attachable to a vehicle and defining engagement slots; a adjustment track movable with respect to the seat secured track and configured to support the seat pan such that the seat pan is movable with the seat adjustment track; a memory mechanism for selectively positioning the adjustment track relative to the secured track, the memory mechanism including a tooth for selectively engaging the support track; a locking mechanism connected to the adjustment track and movable between a locked position wherein the adjustment track is locked to the secured track and an unlocked position wherein the adjustment track is free to move relative to the secured track, the locking mechanism including means for selectively disengaging the memory mechanism tooth from the secured track; wherein the locking mechanism is movable between a first position in which disengagement of the locking mechanism from the secured track disengages the memory mechanism from the secured track, and a second position in which disengagement of the locking mechanism from the secured track leaves the memory mechanism engaged with the secured track.

7. A vehicle seat assembly as defined in Claim 6 wherein the memory mechanism includes a memory stopper having a tooth engageble with the secured track, and wherein the locking mechanism includes a trigger for engaging the secured track and means for selectively lifting the memory stopper tooth from engagement with the secured track.

8. A vehicle seat assembly as defined in Claim 7 wherein the locking mechanism further includes means for selectively moving the memory mechanism relative to the secured track.

9. A vehicle seat assembly as defined in Claim 8 wherein the memory stopper includes a boss for selective engagement with the locking mechanism.

10. A vehicle seat assembly as defined in Claim 9 wherein the locking mechanism further includes and a hook plate pivotally connected to the trigger and selectively engagable with the memory stopper boss.

11. A vehicle seat assembly as defined in Claim 10 wherein the hook plate includes a lift tab for selectively lifting the memory stopper from engagement with the secured track.

12. A vehicle seat assembly as defined in Claim 11 wherein the hook plate is movable between a first position in which disengagement of the trigger from the secured track disengages the memory stopper from the secured track, and a second position in which disengagement of the locking mechanism from the secured track leaves the memory stopper engaged with the secured track.

13. A vehicle seat assembly as defined in Claim 12 further comprising means to rotate the hook plate from the first position to the second position when the seat back is moved to a dumped forward position.

14. A vehicle seat assembly as defined in Claim 13 wherein the hook plate includes a lift tab which is moved from underneath the memory stopper when the hook plate is moved from the first position to the second position.

15. A vehicle seat assembly as defined in Claim 14, wherein the hook plate includes a spring pin and the trigger includes a spring which is engaged by said spring pin when said hook plate is rotated, whereby the spring biases the hook plate toward the pre-rotated hook plate position.

16. A vehicle seat assembly as defined in Claim 15 wherein the memory stopper engages the hook plate upon return of the seat assembly from a forward dump position, whereby the hook plate is rotated to the first position in which the hook plate lift tab is underneath the memory stopper boss.

17. A vehicle seat assembly as defined in Claim 16 wherein the memory stopper engages the trigger upon a return of the seat assembly from a dumped forward position, whereby the trigger re-engages with the secured track.

18. A vehicle seat assembly as defined in Claim 7 further comprising a memory block mounted on the secured track, the memory block including a pivot pin about which the memory stopper is pivotable, and a spring for biasing the memory stopper tooth toward an engaged position with the secured track.

19. A vehicle seat assembly as defined in Claim 18 further comprising a guide member mounted on the secured track, wherein the memory block is secured to and slidable with respect to the guide member.

20. A vehicle seat assembly as defined in Claim 19 wherein the memory block spring is a coil spring mounted about the memory block pivot pin, wherein the coil spring has a first leg engaged with the memory block and a second leg engaged with the memory stopper, wherein the memory stopper is unbiased by the spring until the hook plate engages the memory stopper.

21. A vehicle seat assembly as defined in Claim 11 further including a link rotatable upon movement of the seat back to a dumped forward position to rotate the hook plate lift tab to a position axially spaced from the memory stopper boss, whereby lifting of the hook plate does not affect the position of the memory stopper.

22. A vehicle seat assembly as defined in Claim 20 further including a spring biasing the link to rotate the hook plate lift tab to position the position axially spaced from the memory stopper boss.