GB2041064A - Reclining seat mechanism - Google Patents

Abstract

A latch mechanism for controlling rotation of a vehicle seat back to a reclining position relative to a vehicle seat cushion in which a quadrant 24 is supported by the pivot pin 16 joining the cushion and back for rotation to both, and a link 84 is articulated to the quadrant at a point 27 radially spaced from the pivot pin. A pair of dogs 80, 82 which can be released by operation of a handle, enable the link 84 to be locked in an infinite number of axially spaced positions to provide infinite adjustment of the seat back. <IMAGE>

Description

SPECIFICATION Reclining seat mechanism The present invention relates to a latch mechanism for controlling the reclining movement of the seat back of a vehicle.

As discussed in British Patent Application No. 7 922 629, manually operated latch mechanisms for retaining the reclinable back of a vehicle seat in a desired position are known. However, there is constant pressure on the automative industry to provide latch mechanisms that are more positive, more accessable, lighter, and less expensive than known latch mechanisms.

According to the present invention there is provided a latch mechanism for controlling rotation of a vehicle seat back to a reclining position relative to a vehicle seat cushion, said mechanism comprising a pivot pin joining said seat cushion and seat back for relative rotation, a quadrant supported by said pivot pin for rotation relative to both said seat cushion and seat back, a link pivotally connected to said quadrant at a point radially spaced from said pivot pin and a latch on said seat cushion releaseably engageable with said link in infinitely adjustable biting engagement to enable rotation of said quadrant relative to said seat cushion to be controlled.

Such a latch mechanism provides for infinite adjustment of the seat back relative to a vehicle seat.

In order that the invention will more readily be understood, the following description is given, by way of example only, reference being made to the accompanying drawings, in which: Figure 1 is a schematic side elevational view of a vehicle including one embodiment of latch mechanism according to the present invention; Figure 2 is an enlarged side elevational view, with the seat cover broken away and other portions removed, of the seat shown in Fig. 1 showing the details of the latch mechanism Figure 3 is a side elevational view, similar to Fig. 2, showing the seat back in the fully reclined position; Figure 4 is a side elevational view, similar to Fig. 2, showing the seat back in the forward condition to facilitate access to the rear of a vehicle;; Figure 5 is a detail view of the structure within the circle "5" of Fig. 2 showing the latch in the unlatched condition; Figure 6 is a view of a modified latch in the locked condition; and Figure 7 is a view of the latch of Fig. 6 in the unlatched condition.

Referring to the drawing, Fig. 1 shows, in schematic fashion, a vehicle seat assembly 10, incorporating a latch mechanism in accordance with the subject invention. The seat assembly 10 is of the type conventionally found in the front seat of two-door motor vehicles and comprises a seat cushion 1 2 and a seat back 14.

Referring to Fig. 2 wherein the upholstery of the seat cushion 1 2 and seat back 14 has been deleted and only the structural components nesessary to an understanding of the invention have been illustrated, the seat back 14 is supported for pivotal movement relative to the seat cushion 1 2 as by a pin 1 6 so as to permit the seat back 14 to be folded forwardly to provide access to the rear seat of the associated vehicle as well as to be pivoted rearwardly to a desired reclining position. A latch mechanism, indicated generally by the reference numeral 18, is provided for controlling movement of the seat back 14, for preventing undesired forward pivotal movement of the seat back 14 die to sudden vehicle decelerations, and for accommodating desired forward movement of the seat back 14.

More specifically, a seat cushion bracket 22 is affixed to the frame of the seat cushion 1 2.

The bracket 22 pivotally supports a quadrant 24 by means of the pivot pin 1 6. The quadrant 24 is pivotally supported by the pin 1 6 for rotation relative to the seat cushion bracket 22 as well as to a seat back bracket 26.

Clockwise or reclining rotation of the quadrant 24 relative to the seat cushion bracket 22 is stopped after a predetermined angular displacement by engagement of a pin 27 therein with the end portion 28 of an arcuate slot 29 in the bracket 22. Reclining rotation of the seat back bracket 26 relative to the quadrant 24 is stopped by engagement of a pin 30 in the bracket 26 with the end portion 31 of a slot 32 in the quadrant 24. As more fully described in Applicants copending Application No. 9,922,629, which is incorporated herein by reference, a pivotally supported inertia member cage 40 is supported for rotation relative to the seat back bracket 26 by a pivot pin 42.The inertia member cage 40 carries a transversely extending latch pin 44 that is adapted to cooperate with a shoulder 46 on the quadrant 24 and the edges of an arcuate slot 48 in the seat back bracket 26 to limit forward rotation of the seat back 14.

The inertia member cage 40 is formed with an internal track 54 for the acceptance of a generally disc-shaped inertia member which is rollable therealong, as will be described.

Fig. 2 shows the latch mechanism 1 8 in its normal or latched and upright condition denote by the full line position "c" in Fig. 1. In this condition, the inertia member 56 is positioned to the right of the pivot pin 42 that supports the cage 40 in which position the weight of the inertia member 56 causes the inertia member cage 40 to be biased clockwise. However, rotation of the inertia member cage 40 is limited by engagement of a boss or shoulder 58 thereon with an abutment 60 on the quadrant 24 thereby normally maintaining the pin 44 in alignment with the shoulder 46 on the clutch quadrant 24 so as to be engageable therewith.

Upon the occurrence of sudden vehicle deceleration, the inertia member 56 rolls along the track 54 effecting a counter clockwise bias on the inertia member cage 40 thereby holding the pin 44 at the lower end of the track 48 so that it is maintained in a position to engage the shoulder 46 on the quadrant 24.

Thus, when the vehicle is subject to a deceleration force, forward pivotal movement of the seat back 14 relative to the clutch quadrant 24 and the seat cushion bracket 22 about the pivot pin 1 6 is stopped at the broken line position "B" of Fig. 1, assuming the quadrant 24 is latched relative to the bracket 22, as will be described.

The inertia member cage 40 is positively held in the aforesaid latched position until deceleration ceases and the inertia member 56 returns to the position shown in Fig. 2.

While the bias on the inertia member cage 40 reverses when the seat back 14 moves from the "B" position to the "C" position of Fig.

1, the pin 44 on the inertia member cage 40 is maintained in the locked position shown in Fig. 2, due to engagement of the boss 58 thereon with the abutment 60 on the clutch quadrant 24. Thus, the seat back 14 is normally maintained in the latched condition.

Stated in another manner, the pin 44 does not have to move to a latched position in order to effect locking of the seat back 14 relative to the seat 1 2 upon the occurrence of deceleration of the vehicle.

When the vehicle is in the static condition or, in other words, is not subject to deceleration forces, and it is desired to move the seat back 14 forward relative to the seat 12 to the broken line position "A" in Fig. 1, thereby to facilitate access to the rear seat of the vehicle, the first increment of rotation of the seat back 14 towards the "B" position of Fig. 1, permits the inertia member cage 40 to rotate clockwise, as seen in Fig. 4 of the drawings, under the clockwise bias of the inertia member 56. When the cage 40 rotates clockwise, the pin 44 is raised within the track 48 in the bracket 26 so as to clear the shoulder 46 on the quadrant 24 permitting the seat back 14 to be pivoted forwardly to the "A" position.

Thus, the pin 44 is automatically moved out of the normal or latched condition to accommodate forward movement of the seat back 14 but only when there are no deceleration forces operative on the vehicle. At this time the inertia member 56 is at the right or lowermost portion of its track 54 and exerting a clockwise bias on the inertia member cage 40.

In accordance with the instant invention, latching of the seat back 14 at any desired reclining position intermediate the end positions thereof, is achieved by latching of the quadrant 24 relative to the seat cushion bracket 22 and seat 1 2. Latching is achieved by engagement of a pair of dogs 80 and 82 on the seat cushion bracket 22 with a slidable articulated link 84 is pivotally secured to the quadrant 24 by the pin 27 therein. The dogs 80 and 82 have biting edge portions 86 and 88, respectively, which engage an upper surface 89 of the link 84 in biting engagement.

A pin 90 on the seat bracket 22 supports the dogs 80 and 82 for rotation relative to the link 84. The dogs 80 and 82 are normally biased to the locked condition relative to the link 84 by spring 93. The dogs 80 and 82 are rotated to the unlocked condition by a cam 94 that is actuated by any suitable means, for example a manually operable radial handle 95, (Fig.1).

As best seen in Fig. 3,reclining movement of the seat back 14 is initiated by compression of the spring 93 as by rotation of the handle 95 and cam 94 which effects release of the biting edges 86 and 88 on the dogs 80 and 82, conditioning the quadrant 24 for rotation relative to the bracket 22 about its supporting pin 16. Thereafter a rearward push on the seat back 14 is transmitted to the quadrant 24 by the pin 30 on the seat back bracket 26 causing the quadrant 24 to rotate clockwise with the seat back 14 to a desired reclining position. Release of the handle 95 and cam 94 allows the biting edges 86 and 88 of the dogs 80 and 82 to re-engage the link 84 of the quadrant 24 under the bias of the spring 93 and lock the seat back 14 at the desired reclining position.

Return movement of the seat back 14 is achieved by releasing the dogs 80 and 82, movement of the seat back 14 being effected by the bias of a spring 1 20 which extends between a pin 1 22 on the quadrant 24, the bracket 22 and the pin 27.

Referring to Figs. 6 and 7, a pair of modified dogs 100 and 102 are mounted on spaced apart pivots and have pairs of biting teeth 104-106 and 108-110, respectively, that are engageable with the link 84 in biting engagement. In this manner locking forces on the link 84 are balanced.

Claims (8)

1. A latch mechanism for controlling rotation of vehicle seat back to a reclining position relative to a vehicle seat cushion, said mechanism comprising a pivot pin jointing said seat cushion and seat back for relative rotation, a quadrant supported by said pivot pin for rotation relative to both said seat cushion and seat back, a link pivotally connected to said quadrant at a point radially spaced from said pivot pin and a latch on said seat cushion releasably engageable with said link in infinitely adjustable biting engagement to enable rotation of said quadrant relative to said cushion to be controlled.

2. A latch mechanism according to claim 1, wherein said latch comprises a pair of releasable infinitely adjustable dogs having biting edges, respectively, engageable with said link, rotatable cam means engageable with said dogs to effect disengagement thereof from said link, and a handle manually operable to effect rotation of said cam.

3. A latch mechanism according to claim 2, wherein said seat cushion has a pin thereon for supporting said dogs for rotation, said link being interposed between said supporting pin and the biting edges of said dogs.

4. A latch mechanism according to claim 2, wherein said latch comprises a pair of dogs each having a pair of biting edges engageable with said link.

5. A latch mechanism according to claim 2, 3 or 4. wherein spring means normally bias said dogs into engagement with said link to preclude movement thereof relative to said seat cushion in either direction.

6. A latch mechanism according to any preceding claim, including means on said seat back for controlling rotation of said seat back relative to said quadrant.

7. A latch mechanism for controlling rotation of a vehicle seat back to a reclining position relative to a vehicle seat cushion, substantially as hereinbefore described with reference to and as illustrated in Figs. 1 to 5 of the accompanying drawings.

8. A latch mechanism according to claim 7, modified substantially as hereinbefore described with reference to and as illustrated in Figs. 6 and 7 of the accompanying drawings.