WO2000055005A1

WO2000055005A1 - Automotive seat back reclining mechanism

Info

Publication number: WO2000055005A1
Application number: PCT/CA2000/000265
Authority: WO
Inventors: Omar D. Tame
Original assignee: Magna Seating Systems Inc.
Priority date: 1999-03-12
Filing date: 2000-03-13
Publication date: 2000-09-21
Also published as: AU3140200A

Abstract

A recliner assembly (16) for providing pivotal movement of a seat back (14) relative to a seat cushion (12) includes a seat cushion bracket (18) secured to the seat cushion and a seat back bracket (22) secured to the seat back. A locking recliner mechanism (26) pivotally interconnects the seat back bracket to the seat cushion bracket. The locking recliner mechanism is operable between an unlocked condition for providing the pivotal movement of the seat back between a plurality of reclined positions and a locked condition for locking the seat back in any one of the reclined positions. A drive shaft (34) is coupled between the seat cushion bracket and the locking recliner mechanism for defining a seat back pivot bracket and rotating the locking recliner mechanism between the locked and unlocked conditions. An elongated release lever (56) has a first end (58) pivotally connected to the seat cushion bracket defining a release lever pivot axis (B) spaced laterally from the seat back pivot axis (A) and a second free end (6) forming a handle. An angular displacement link (68) has a first end (70) fixedly secured to the drive shaft (34) and a second end (74) rotatably coupled to the release lever (56) to define a link axis (C) spaced laterally from the seat back pivot axis and the release lever pivot axis. The link rotates the drive shaft and actuates the locking recliner mechanisms between the locked and unlocked conditions in response to the pivotal movement of the release lever about the release lever pivot axis.

Description

AUTOMOTIVE SEAT BACK RECLINING MECHANISM

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a recliner assembly for providing pivotal movement of a seat back relative to a seat cushion.

2. Description of the Prior Art

Seat assemblies for use in automotive vehicles typically include a seat cushion secured to the floor of the vehicle and a seat back coupled to the seat cushion for supporting a seat occupant in an upright seating position. The seat back is commonly pivotally coupled to the seat cushion by a reclmer mechanism for providing pivotal movement of the seat back relative to the seat cushion between the upright seating position and a plurality of reclined positions. The recliner mechanism may also releasably lock the seat back in the upright seating position and any one of the reclined positions. The seat assembly typically includes a release lever directly connected to the recliner mechanism for actuating the recliner mechanism between an unlocked condition for providing pivotal movement of the seat back and an unlocked condition for locking the seat back in one of the seating or reclined positions. Such a recliner mechanism is exemplified in United States Patent No. 5,664, 836 to Takagi, issued September 9, 1997.

The release lever generally rotates a drive shaft connected to the recliner mechanism to actuate the reclmer mechanism between the locked condition and the unlocked condition. However, the release lever must typically be rotated through a large range of angular displacement in order to fully actuate the recliner mechanism. Therefore, it is desirable to provide a recliner assembly for providing pivotal movement of the seat back relative to the seat cushion wherein the angular displacement from the rotation of the drive shaft is greater than the angular displacement from the pivotal movement of the release lever to actuate the recliner mechanism between the locked condition and the unlocked condition. SUMMARY OF THE INVENTION

. Accordingly, the present invention includes a reclmer assembly for providing pivotal movement of a seat back relative to a seat cushion. The recliner assembly comprises a seat cushion bracket adapted to be secured to the seat cushion and a seat back bracket adapted to be secured to the seat back. The seat assembly further includes a locking recliner mechanism operatively coupled between the seat cushion bracket and the seat back bracket. The locking recliner mechanism is operable between an unlocked condition for providing pivotal movement of the seat back bracket between a plurality of reclined positions and a locked condition for locking the seat back bracket in one of the reclined positions. The seat assembly also includes a drive shaft rotatably coupled to the seat cushion bracket and defining a seat back pivot axis. The drive shaft is operatively coupled to the locking recliner mechanism for actuating the locking recliner mechanism between the locked condition and the unlocked condition in response to rotation of the drive shaft. The drive shaft has opposite first and second distal ends. The seat assembly additionally includes an elongated release lever having a first end pivotally coupled to the seat cushion bracket defining a release lever pivot axis spaced laterally from the seat back pivot axis and a second free end. The release lever is pivotal between a non-actuated position with the locking recliner mechanism in the locked condition and an actuated position with the locking recliner mechanism in the unlocked condition. The seat assembly also includes an angular displacement link having a first end fixedly secured to the first distal end of the drive shaft and a second end coupled to the release lever between the first end and the second free end for rotating the drive shaft and actuating the locking recliner mechanism between the locked condition and the unlocked condition in response to the pivotal movement of the release lever between the non-actuated position and the actuated position.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: Figure 1 is an environmental perspective view of a vehicle seat assembly having a reclining assembly according to the subject invention;

Figure 2 is a side view of the reclining assembly of Figure 1 in a locked condition; Figure 3 is a side view of the reclining assembly in an unlocked condition; and Figure 4 is a rear view of the reclining assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Figure 1, a seat assembly is generally shown at 10, such as is commonly used for supporting a seat occupant in an automotive vehicle (not shown). The seat assembly 10 includes a generally horizontal seat cushion 12 for supporting the seat occupant on the seat assembly 10 and a generally upright seat back 14 for supporting the seat occupant in a generally upright seating position. The seat cushion 12 and seat back 14 typically include a frame structure for supporting a contoured cellular foam pad encased in a fabric trim cover as is conventional in the automotive seat art. A recliner assembly 16 interconnects the seat cushion 12 and the seat back 14 for providing pivotal movement of the seat back 14 from the generally upright seating position to a plurality of reclined position for selective comfort or adjustment by the seat occupant.

Referring to Figures 2 and 3, the recliner assembly 16 includes a seat cushion bracket 18 adapted to be secured to the seat cushion 12. More specifically, the seat cushion bracket 18 is generally a stamped metal plate fixedly secured to the frame structure of the seat cushion 12 by a plurality of fasteners, such as bolts, as shown at 20. The recliner assembly 16 further includes a seat back bracket 22 adapted to be secured to the seat back 14. Similarly, the seat back bracket is a stamped metal plate fixedly secured to the frame structure of the seat back 14 by fasteners, such as bolts or welds, as shown at 24. The seat cushion bracket 18 and seat back bracket 22 overlapped and are aligned along a seat back pivot axis shown at A.

Referring to Figure 4, the recliner assembly 16 also includes a locking recliner mechanism 26 operatively coupled between the seat cushion bracket 18 and the seat back bracket 22. The locking recliner mechanism 26 is operable between an unlocked condition for providing pivotal movement of the seat back bracket 22, and hence the seat back 14, between the upright seating position and the plurality of reclined positions and a locked condition for locking the seat back bracket 22, and seat back 14, in the upright seating position or one of the reclined positions. The locking recliner mechanism 26 of the preferred embodiment of Figures 1-4 is further set forth and fully described in applicant's co-pending PCT application number PCT\CA99\00653, published February 10, 2000 and incorporated herein by reference. The locking recliner mechanism 26 includes a support plate 28 fixedly secured by fasteners 30, such as bolts or rivets, to the seat back bracket 22. The locking recliner mechanism 26 further includes a rotating plate 32 coupled to the support plate 28 and lockingly engagable therewith for actuating the recliner mechanism 26 between the locked condition and the unlocked condition as described in applicant's co-pending application.

The recliner assembly 16 further includes an elongated, cylindrical drive shaft 34 rotatably coupled to the seat cushion bracket 18 and defining the seat back pivot axis A. The pivot shaft 34 is also operatively coupled to the locking recliner mechanism 26 for actuating the locking recliner mechanism 26 between the locked condition and the unlocked condition in response to rotation of the pivot shaft 34. More specifically, as shown in Figure 4, the pivot shaft 34 includes opposite first and second distal ends 36, 38. The pivot shaft 34 is rotatably journaled to the seat cushion bracket 18 by a bearing 40 adjacent the first distal end 36. The pivot shaft 34 extends from the first distal end 36 to the center of the locking recliner mechanism 26 where the second distal end is operatively coupled between the support plate 28 and the rotating plate 32.

The recliner assembly 16 also includes an elongated, cylindrical pivot shaft 42 having a first end 44 fixedly secured to the support plate 28 of the locking recliner mechanism 26 and a second distal end 46 spaced outwardly from the locking recliner mechanism 26 and seat back bracket 22. The pivot shaft 42 extends through a center bore in the seat back bracket 22 to support the seat back 14 during pivotal movement between the upright seating position and the reclined positions. A coil spring 48 is supported by and fixedly secured between the second distal end 46 of the pivot shaft 42 and the seat cushion bracket 18. That is, the coil spring 48 includes a first end 50 secured within a slot 52 in the second distal end 46 of the pivot shaft 42 and a first end 54 secured to a portion of the seat cushion bracket 18 as shown in Figure 4. The coil spring 48 biases the seat back bracket 22, and thus the seat back 14, from the reclined positions towards the upright seating position. Referring to Figures 2-4, the recliner assembly 16 further includes an elongated release lever 56 having a first end 58 pivotally coupled to the seat cushion bracket 18 by a pivot pin 60 defining a release lever pivot axis B spaced laterally from the seat back pivot axis A. The release lever 56 also includes a second free end 62 defining a handle for operating the lever 56 by the seat occupant. The release lever 56 is pivotal about the pivot axis B between a non-actuated position with the locking recliner mechanism 26 in the locked condition, as shown in Figure 2, and an actuated position with the locking recliner mechanism 26 in the unlocked condition, as shown in Figure 3. The release lever 56 is generally L-shaped and includes a leg portion 64 connected to the seat cushion bracket 18 at the first end 58 and an arm portion 66 extending from the leg portion 64 to the second free end 62 forming the handle of the lever 56.

The recliner assembly 16 includes an angular displacement link 68 having a first end 70 fixedly secured, such as by a retaining clip 72, to the first distal end 36 of the drive shaft

34 and a second end 74 coupled to the release lever 56 by a pivot pin 76. More specifically, the second end 74 of the link 68 is rotatably journaled to the leg portion 64 of the release lever 56 between the first end 58 and the second free end 62 and the arm portion 66. The pivot pin 76 connecting the release lever 56 and the link 68 defines a link axis C spaced laterally from each of the seat back pivot axis A and the release lever pivot axis B. More specifically, the seat back pivot axis A is positioned between the release lever pivot axis B and the link axis C. The link 68 further extends between the seat back pivot axis A and the link axis C. The link 68 rotates the drive shaft 34, and therefore, actuates the locking recliner mechanism 26 between the locked condition and the unlocked condition in response to the pivotal movement of the release lever 56 between the non-actuated position and the actuated position.

In other words, as depicted in Figure 3, the pivotal movement of the release lever 56 defines a first range of angular displacement X and the pivotal movement of the link 68 defines a second range of angular displacement Y which is greater than the first range of angular displacement X in relation to the pivotal movement of the release lever 56. The increase second range of angular displacement of the pivotal movement of the link 68 increases the rotation of the drive shaft 34 to actuate the recliner mechanism 26 from the locked condition to the unlocked condition with minimal angular displacement resulting from the pivotal movement of the release lever 56 from the non-actuated position to the actuated position.

In operation, referring to Figures 1 and 2, the seat assembly 10 is shown with the seat back 14 and the associated seat back bracket 22 in the upright seating position for supporting the seat occupant. If the seat occupant desires to recline the forward or rearward angle of the seat back 14 relative to the seat cushion 12, the seat occupant operates the recliner assembly 16. When the release lever 56 is pivoted in the clockwise direction about the release lever axis B defined by the pivot pin 60, the lever 56 is moved about the first range of angular displacement X, as shown in Figure 3. The release lever 56 pulls upwardly, or in the clockwise direction, on the second end 74 of the angular displacement link 68 to pivot the link 68 about the seat back pivot axis A. The link 68 rotates the drive shaft 34 clockwise to release the locking recliner mechanism 26 from the locked condition to the unlocked condition. With the release lever 56 in the actuated position, the seat back 14 may be pivoted about the seat back pivot axis A, and the pivot shaft 42, to any one of a plurality of reclined positions relative to the seat cushion 12. Additionally, with the release lever 56 in the actuated position, the coil spring 48 biases the seat back 14 counter-clockwise toward the upright seating position of Figure 1.

As illustrated in Figure 3, the second range of angular displacement Y of the link 68 is greater than the first range of angular displacement X of the release lever 56 when the release lever 56 is pivoted from the non-actuated position of Figure 2 to the actuated position of Figure 3. Therefore, the link 68 rotates the drive shaft 34 further in the clockwise direction than it would be if connected directly to the release lever 56. The link 68 minimizes the amount of pivotal movement, or angular travel, required by the release lever 56 in order to rotate the drive shaft 34 and unlock the locking release mechanism 26 to recline the seat back 14.

It should be appreciated that the recliner assembly 16 may be included on either opposing side of the seat assembly 10 or only on one side, i.e. inboard or outboard, of the seat assembly 10. If the recliner assembly 16 is included on only one side of the seat assembly

10, the opposing side may include any commonly known pivotal connection between the seat cushion 12 and the seat back 14. The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.

Obviously, many modification and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described.

Claims

What is claimed is:

1. A recliner assembly for providing pivotal movement of a seat back relative to a seat cushion, said recliner assembly comprising: a seat cushion bracket adapted to be secured to the seat cushion; a seat back bracket adapted to be secured to the seat back; a locking recliner mechanism operatively coupled between said seat cushion bracket and said seat back bracket, said locking recliner mechanism operable between an unlocked condition for providing pivotal movement of said seat back bracket between a plurality of reclined positions and a locked condition for locking said seat back bracket in one of said reclined positions; a drive shaft rotatably coupled to said seat cushion bracket and defining a seat back pivot axis, said drive shaft operatively coupled to said locking recliner mechanism for actuating said locking recliner mechanism between said locked condition and said unlocked condition in response to rotation of said drive shaft, said drive shaft having opposite first and second distal ends; an elongated release lever having a first end pivotally coupled to said seat cushion bracket defining a release lever pivot axis spaced laterally from said seat back pivot axis and a second free end, said release lever pivotal between a non-actuated position with said locking recliner mechanism in said locked condition and an actuated position with said locking recliner mechanism in said unlocked condition; and an angular displacement link having a first end fixedly secured to said first distal end of said drive shaft and a second end coupled to said release lever between said first end and said second free end for rotating said drive shaft and actuating said locking recliner mechanism between said locked condition and said unlocked condition in response to said pivotal movement of said release lever between said non-actuated position and said actuated position.

2. A recliner assembly as set forth in claim 1 wherein said angular displacement link is rotatably journaled to said release lever to define a link axis spaced laterally from each of said seat back pivot axis and said release lever pivot axis.

3. A recliner assembly as set forth in claim 2 wherein said seat back pivot axis is positioned between said release lever pivot axis and said link axis.

4. A recliner assembly as set forth in claim 3 wherein said link extends between said link axis and said seat back pivot axis and pivotal about said seat back pivot axis to rotate said drive shaft and actuate said locking recliner mechanism in response to pivotal movement of said release lever.

5. A recliner assembly as set forth in claim 4 wherein said pivotal movement of said release lever defines a first range of angular displacement and said pivotal movement of said link defines a second range of angular displacement which is greater than said first range of angular displacement in relation to said pivotal movement of said release lever.