GB2343839A

GB2343839A - Recliner mechanism

Info

Publication number: GB2343839A
Application number: GB9825636A
Authority: GB
Inventors: Karl-Gunnar Lindblad
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1998-11-23
Filing date: 1998-11-23
Publication date: 2000-05-24
Also published as: GB9825636D0

Abstract

A recliner mechanism for a vehicle seat has a support plate(2) to be connected to the squab and has a support arm(20) to be connected to the back of the seat. The support plate(2) defines a plurality of generally radially outwardly extending slots(8) and the support arm(20) is connected to two plates(12,13) which define similar radially outwardly extending slots(15) having a different orientation to the slots(8). Horizontal rods(29) extend through the co-aligned slots and the ends of the rods are received within a spiral groove in drive wheels(30). On rotating the drive wheels(30) the rods(29) are moved generally radially inwardly causing the support arm(20) to execute a controlled pivotal movement relative to the support plate(2). The mechanism is never in an unlocked position, even during adjustment of the seat.

Description

DESCRIPTION OF INVENTION "IMPROVEMENTS IN OR RELATING TO A RECLINER MECHANISM" THE PRESENT INVENTION relates to a recliner mechanism, and more particularly relates to a recliner mechanism for use in a vehicle seat.

It is conventional to provide a recliner mechanism in a vehicle seat, such as a seat used in a motor car. The recliner effectively forms a pivotal connection between the squab and the back-rest of the seat and permits the angular orientation of the back-rest relative to the squab to be adjusted.

A typical prior proposed recliner is a relatively complicated mechanism.

Many prior proposed recliner mechanisms incorporate a locking arrangement adapted to lock the back-rest of the seat in a selected position relative to the squab of the seat. The locking mechanism has to be released before the angle of inclination of the back-rest can be adjusted. It can be very detrimental for a passenger travelling in the seat provided with the recliner if the recliner is actually in the unlocked condition when an accident occurs.

The present invention seeks to provide an improved recliner which, although incorporating a relatively simple mechanism, will always retain the back-rest in the desired angular position relative to the squab, even if the position of the back-rest is being adjusted, relative to the squab, at the very instant that an accident occurs.

According to this invention there is provided a recliner mechanism for the back of a seat, the recliner mechanism having a support plate to be connected to the squab of the seat, and a support arm to be connected to the back of the seat, the support plate and support arm being associated with respective connecting means, the connecting means being substantially parallel and lying adjacent one another, and being pivotally inter-connected so that the connecting means associated with the support arm may effect a pivotal motion relative to the connecting means associated with the support plate, each connecting means being provided with means defining at least one engagement path, each engagement path extending from a radially inner position adjacent the pivot axis to a radially outer position remote from the pivot axis, the engagement paths of the respective connecting means having respective different orientations, relative to the radial direction, engagement means being provided engaging said two engagement paths, whilst being capable of movement along the engagement paths, uni-directional drive means being provided adapted to move the engagement means from a radially outer position to a radially inner position and vice-versa to effect a relative movement between the two connecting means.

Preferably the connecting means each define a plurality of said engagement paths, and there are a plurality of engagement means each engaging a unique engagement path on each of the two said connecting means.

Conveniently the or each engagement path on one connecting element is inclined to define a substantially clockwise direction of movement when moving from the inner end of the engagement path to the outer end of the engagement path, whereas the engagement path on the other connecting element is inclined to define a substantially anti-clockwise movement on moving from the inner end of the engagement path to the outer end of the engagement path.

Conveniently at least some of the engagement paths on one connecting element are of arcuate form.

Preferably the means defining the or each engagement path is a slot and each engagement element is a rod passing through respective slots on the respective connecting elements where the slots intersect.

Conveniently the uni-directional drive means comprises a cam mechanism.

Advantageously the recliner mechanism has at least one drive wheel, constituting a cam mechanism, and means to rotate the drive wheel, the drive wheel incorporating a spiral or part spiral groove adapted to engage the or each rod so that the or each rod is moved along at least one slot in each of said connecting means on rotation of the drive wheel.

Preferably the connecting means associated with the support plate is a connecting region formed integrally with the support plate, and the connecting means associated with the support arm are connecting plates located adjacent the connecting region of the support plate, the rods passing through slots formed in the co-aligned connecting region and connecting plates being received within helical grooves formed in two said drive wheels mounted adjacent the exterior of the faces of said connecting plates.

Conveniently the means to drive the drive wheels is a control knob, the control knob engaging a toothed gear wheel, the toothed gear wheel engaging a toothed periphery of one drive wheel, means being provided to drive the other said drive wheel in synchronism with said one drive wheel.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings which: FIGURE 1 is a perspective view of the principal parts of a recliner mechanism in accordance with the invention in an assembled condition, FIGURE 2 is a view illustrating the recliner of Figure 1 with the components being shown in an exploded condition, FIGURE 3 is a view corresponding to Figure 1 illustrating the recliner with one drive wheel removed, FIGURE 4 is a view showing a plate, forming part of the recliner, adapted to be connected to the squab of the seat, FIGURE 5 is a view illustrating an assembly forming part of the recliner adapted to be connected to the back-rest of the seat, FIGURE 6 is an elevational view of one drive wheel forming part of the recliner mechanism, FIGURE 7 is a sectional view of the drive wheel of Figure 6, FIGURE 8 is a side view, with parts shown in phantom, illustrating the recliner in the fully reclined position, and FIGURE 9 is a view corresponding to Figure 8 showing the recliner in the fully elevated position.

Referring to the accompanying drawings a recliner mechanism I in accordance with the invention has a support plate 2. The support plate 2 defines a first region 3 provided with plurality apertures 4 by means of which the support plate may be connected to the squab of the seat. The support plate 2 incorporates a substantially circular planar connecting region 5. Formed in the centre of the connecting region 5 is an aperture 6, which may be provided with a bush 7 that defines a pivotal axis. Formed in the connecting region of the support plate 5 are a plurality of slots 8, which surround the aperture 6. Each slot has two opposed ends, with one end of the slot being located adjacent the aperture 6, and the other end of the slot being spaced further away from the aperture 6. Thus, each slot extends from a radially inner position adjacent the pivotal axis defined by the bush 7 to a radially outer position remote from that axis. The slots do not, however, each extend radially outwardly relative to the aperture 6, but instead are inclined relative to the radial direction. The slots are inclined so that the slots define a generally anticlockwise direction of movement on moving from the inner end of each slot to the outer end of each slot, as viewed in the orientation of the figures.

It is to be observed (see Figure 4), that the slots are not uniformly spaced from the aperture 6, but each slot is spaced from the aperture by a different distance, the inner ends of the slots defining a spiral line 9, one end of which is relatively close to the aperture 6 and the other end of which is spaced further from the aperture, and the outer ends of the slots defining a similar spiral line 10.

The two slots having their inner ends closest to the aperture 6 are linear, but the remaining slots are arcuate. The radius of curvature of the arcuate slots is such that the slots having their inner ends furthest from the aperture 6 have the shortest radius of curvature.

The sides of each slot form two parallel opposed engagement surfaces as will become clear from the following description.

A pivot pin 11 passes through the bush 7 in the aperture 6 in the connecting region of the support plate 2, and extends to either side of the support plate 2.

Two connecting plates 12,13 are provided which are of identical design.

Each connecting plate comprises a substantially circular region having a central aperture 14 which receives the pivot pin 11. Surrounding the aperture 14 are a plurality of elongate linear slots 15 which are similar to the slots 8 as described above. Each elongate slot two opposed ends with one end of the slot being located at a radially inner position adjacent the aperture 14, and the other end being spaced further away from the aperture 14 at a radially outer position.

The slots 15 do. not, however, each extend radially outwardly relative to the aperture 14, but instead are inclined relative to a radial line passing outwardly from the aperture 14 through the region of each slot 15. In the connecting plates the slots 15 are inclined so as to define a generally clockwise direction of rotation on movement from the inner end of each slot to the outer end of each slot.

The slots 15 are not uniformly spaced from the aperture 14, but the inner ends of the slots define a spiral line 16, one end of which is relatively close to the aperture 14 and the other end of which is spaced further from the aperture 14, and similarly the outer ends of the slots define a spiral line 17.

Each connecting plate is provided with an outwardly directed lug 16' defining an aperture 17', and the upper part of each connecting plate 13 is provided with two apertures 18,19.

The connecting plates 12,13 are connected to a support arm 20. The support arm 20 has a lower region defining two apertures 21,22, and this region is located between the upper parts of the connecting plates 12 and 13, with the apertures 18 and 19 in the connecting plates 12,13 being co-aligned with the apertures 21,22 in the lower part of the support arm 20 to enable appropriate fastening means, such as rivets, to be passed through the co-aligned apertures to connect the elements together.

The lower part of the support arm 20 is provided with an arcuately recessed edge 23 which is slightly spaced from the arcuate periphery of the circular connecting region of the support plate 2. The connecting plates 12,13 thus lie immediately adjacent, and in spaced parallelism with, the connecting region 5 of the support plate 2. The connecting plates 12,13 are identical and are positioned so that the slots 15 of the two connecting plates are co-aligned.

The support arm 20 incorporates two upwardly directed fingers 24,25, each of which defines apertures 26,27 to enable the support arm 20 to be connected to the framework constituting the back-rest of a seat.

The pivot pin 11 which passes through the bush 7 provided in the aperture 6 in the connecting region 5 of the support plate 2 extends through the central aperture 14 of the connecting plate 13, and also passing through the aperture 14 in the connecting plate 12. The ends of the pivot pin 11 project beyond the opposed outer faces of the connecting plates 12,13.

A plurality of strong rods 29 are provided. The diameter of each rod 29 is slightly less than the width of the slots 8 and 15. Each rod 29 passes through one slot 8 formed in the connecting region of the support plate 2, and through one slot 15 formed in each of the connecting plates 12 and 13. The free ends of each rod 29 project beyond the connecting plates 12,13 and can be seen in Figure 3. Each rod 29 engages a unique slot 8 on the support plate and also engages a unique slot on each of the connecting plates 12,13. Each slot 8,15, only receives one rod 29.

Mounted on each of the exposed ends of the pivot pin 11 is a drive wheel 30. The drive wheel 30 has a toothed exterior 31. On the inner face of the drive wheel, however, is a spiral groove 32. The inner-most turn of the spiral groove has substantially the same configuration as that of the spiral lines 9 and 16 which define the position of the inner-most ends of the slots 8 and 15 formed in the connecting region of the support plate 2, and the connecting plate 13, whilst the outer turns of the spiral groove have a configuration equivalent to that of the spiral lines 10 and 17 defining the position of the outer-most ends of the slots 8 and 15. The spiral groove 32 is of uniform configuration. The groove 32 has a width which is slightly greater than the diameter of each rod 29.

Whilst one drive wheel 30 has been illustrated and described, it is to be appreciated that the other drive wheel will be of mirror-image configuration, so that the spiral groove of the other wheel is of the opposite sense of rotation.

The drive wheels 30 are mounted on the ends of the pivot pin 11, with the ends of the rods 29 being received within the spiral grooves 32 formed on the inner faces of the drive wheels 30.

A manually operable control knob 34 is provided mounted on a shaft 35 that carries a boss 36 that is received as a friction fit within the hollow interior of a cog 37 that is rotatably mounted on the support plate 2. The periphery of the cog 37 is in engagement with the toothed periphery of one of the drive wheels 30, such that rotation of the knob 34 will cause rotation of that drive wheel 30.

At a position spaced from the cog 37, a second cog 38 is provided The cog 38 is mounted on the shaft 39 which extends from the cog 38, through the aperture 17'provided in the lug 16'on the connection plate 13, through a bush 40 which is located between the connection plate 13 and the connection plate 12, and through the aperture 17'formed in the lug 16'of the connection plate 12. Mounted on the shaft 39 at a position adjacent the face of the connection plate 12 which is facing away from the support arm 22 is a second cog wheel 41 which engages the toothed outer periphery of the drive wheel 30 that is mounted adjacent the connecting plate 12.

It is to be appreciated, therefore, that movement of the control knob 34 will effect rotation of one drive wheel 30, thus effecting rotation of the cog 38 and the associated shaft 39, consequently causing rotation of the cog 41, and leading to rotation of the other drive wheel 30 in synchronism with the drive wheel 30 which is driven by the cog 37.

The shaft 39 may extend across the entire width of the seat where the shaft 39 will engage corresponding parts of a corresponding recliner mechanism, enabling manipulation of a knob provided on one side of the seat to effect the simultaneous control of two recliner mechanisms provided at opposite sides of the seat.

When the recliner mechanism is in the fully reclined position, as shown in Figure 8, each rod 29 will be located at the inner-most end of each of the slots through which the rod passes. The rods will also be located in the innermost turn of each helical slot 32 formed on the drive wheel 30. On rotation of the knob 34 in an anti-clockwise direction, the drive wheel 30 will rotate in a clockwise direction, when viewed from the perspective of the accompanying drawings. Of course, the drive wheel 30 on the opposite side of the mechanism will rotate in synchronism. Consequently, the rods 29 are moved generally radially outwardly as the ends of the rods are trapped in the helical grooves on the inner faces of the drive wheels 30.

As a consequence of this generally radially outward movement, because the slots formed in the connecting region 5 are inclined relative to the radial direction with an opposite sense to the slots formed in the connecting plates 12 and 13, the connecting plates 12 and 13 will rotate relative to the support plate, thus adjusting the angle of inclination of the back-rest. This procedure continues until the fully upright position of Figure 9 is achieved, in which it can be seen that the rods 29 are located at the outer-most ends of the slots. At this stage the ends of the rods 29 are located in the outer-most turn of the helical groove 32 formed in each drive wheel 30.

Since the slots formed in the connecting plates 12 and 13 have a different orientation relative to the slots formed in the connection region of the support plate 2, that is to say the angle of inclination of the slots relative to the radial direction is different, the radial outward movement of the rods causes back-rest to move, and thus the angle of inclination of the back-rest may be altered.

If a force is applied to the back-rest of the seat, for example, tending to move the back-rest rearwardly from the fully upright position, the force will be applied, by the connecting plates 12,13 to the rods 29, tending to make the rods move about the axis of the pivot pin 11 in a counter-clockwise direction.

However, this will tend to move the rods 29 radially inwardly, along the slots 8 formed in the connecting region 5 of the support plate 2, because the support plate is firmly connected to the squab of the seat. This will bring the rods firmly into engagement with the inner side-wall of the channel 32 formed in the drive wheel 30, consequently preventing rotation of the drive wheel 30.

Thus the drive wheel 30 is effectively a cam arrangement, converting rotational movement of the drive wheel into a substantially linear movement of each of the rods along the respective channels, and thus constitutes a uni- directional drive, since whilst the drive wheel 30 may be rotated to move the rods, movement of the rods will not drive the drive wheel 30.

It is to be appreciated, therefore, that the described embodiment of the invention provides a relatively simple recliner mechanism which is never in an "unlocked"condition, even during adjustment of the angle of inclination of the back of the seat.

In the described embodiment some of the slots in the support plate 2 are arcuate. Whilst theoretically linear slots could be used, it is felt that the use of arcuate slots in this way will minimise the risk of the mechanism jamming.

Claims

CLAIMS: 1. A recliner mechanism for the back of a seat, the recliner mechanism having a support plate to be connected to the squab of the seat, and a support arm to be connected to the back of the seat, the support plate and support arm being associated with respective connecting means, the connecting means being substantially parallel and lying adjacent one another, and being pivotally interconnected so that the connecting means associated with the support arm may effect a pivotal motion relative to the connecting means associated with the support plate, each connecting means being provided with means defining at least one engagement path, each engagement path extending from a radially inner position adjacent the pivot axis to a radially outer position remote from the pivot axis, the engagement paths of the respective connecting means having respective different orientations, relative to the radial direction, engagement means being provided engaging said two engagement paths, whilst being capable of movement along the engagement paths, uni-directional drive means being provided adapted to move the engagement means from a radially outer position to a radially inner position and vice-versa to effect a relative movement between the two connecting means.
2. A recliner mechanism according to Claim I wherein the connecting means each define a plurality of said engagement paths, and there are a plurality of engagement means each engaging a unique engagement path on each of the two said connecting means.
3. A recliner mechanism according to Claim 1 or 2 wherein the or each engagement path on one connecting element is inclined to define a substantially clockwise direction of movement when moving from the inner end of the engagement path to the outer end of the engagement path, whereas the engagement path on the other connecting element is inclined to define a substantially anti-clockwise movement on moving from the inner end of the engagement path to the outer end of the engagement path.
4. A recliner mechanism according to any one of the preceding Claims wherein at least some of the engagement paths on one connecting element are of arcuate form.
5. A recliner mechanism according to any one of the preceding Claims wherein the means defining the or each engagement path is a slot, and each engagement element is a rod passing through respective slots on the respective connecting elements where the slots intersect.
6. A recliner mechanism according to any one of the preceding Claims wherein the uni-directional drive means comprises a cam mechanism.
7. A recliner mechanism according to Claim 5 wherein the recliner mechanism has at least one drive wheel, constituting a cam mechanism and means to rotate the drive wheel, the drive wheel incorporating a spiral or part spiral groove adapted to engage the or each rod so that the or each rod is moved along at least one slot in each of said connecting means on rotation of the drive wheel.
8. A recliner mechanism according to Claim 7 wherein the connecting means associated with the support plate is a connecting region formed integrally with the support plate, and the connecting means associated with the support arm are connecting plates located adjacent the connecting region of the support plate, the rods passing through slots formed in the co-aligned connecting region and connecting plates being received within helical grooves formed in two said drive wheels mounted adjacent the exterior of the faces of said connecting plates.
9. A recliner mechanism according to Claim 8 wherein the means to drive the drive wheels is a control knob engaging a toothed gear wheel, the toothed great wheel engaging a toothed periphery of one drive wheel, means being provided to drive the other said drive wheel in synchronism with said one drive wheel.
10. A recliner mechanism substantially as herein described with reference to and as shown in the accompanying drawings.
11. Any novel feature or combination of features disclosed herein.