GB2280362A - A reclining chair Mechanism - Google Patents

Abstract

A reclining chair mechanism comprises two side elements 10 each including a chair frame element 11, a seat frame element 12 and interconnecting rear and front levers 13 and 14. Toggle mechanism 16 is provided between the chair and seat element 11, 12 and opening of the toggle mechanism 16 moves the side mechanism 10 through the desired seat positions. The toggles are interconnected by a cross member (17, Fig. 1b) which is moved by a linear actuator. A foot rest mechanism is indicated at 15. <IMAGE>

Description

A Reclining Chair Mechanism This invention relates to reclining chair mechanisms and in particular, but not exclusively, to mechanisms which are suitable for motorising.

There is a considerable market in chairs which recline, lift or do both. Proposals have been made for motorising the lifting and lifting reclining chairs, but the geometry of reclining chair mechanisms has not lent itself to motorisation. Further existing reclining mechanisms tend to allow the seat to drop suddenly downwards as the chair moves from its full reclined position to its first reclined position.

Existing reclining chair mechanisms are of the type comprising a pair of side mechanisms locatable between a chair frame and a seat frame of a reclinable chair, at respective sides of the chair frame; each side mechanism comprising a first element locatable on the chair frame, a second element locatable on the seat frame, respective levers pivotably interconnecting the elements at respective ends thereof to form a four bar linkage, the front lever being itself formed by two pivoted lever sections, so that the second element can be moved from a first position in which it is generally parallel to the first element, to a second position in which is inclined to the first element and third position in which it is further inclined to the first element, these positions corresponding to a seated position, a first recline position and a fully reclined position.

The present invention consists in a reclining chair mechanism of the type described characterised in that the mechanism includes: a) a toggle for each side mechanism interconnecting the elements adjacent the second lever, and b) a cross member interconnecting the toggles, whereby by movement of the cross member in a sense to open the toggles, the second element can be moved from its first position to its second position and, subsequently, to its third position.

It will be understood that reverse movement of the cross member reverses the movements of the mechanism.

For the purposes of this specification the terms front and back refer to the front and back of the chair in which it is intended the mechanism will be mounted.

The mechanism can further include a further cross member extending between the first elements adjacent the first levers, in which case a linear actuator may be mounted between the cross members for moving the first cross member.

The cross members may have respective trunnions for pivotably supporting the respective ends of the actuator.

The first cross member may be connected to the corresponding lever of each toggle at a location spaced from a line joining the pivots of its respective corresponding lever. In this case each corresponding lever may be generally in the form of an inverted isosceles triangular with one pivot at the apex and a pivot and the cross member at respective corners of the base. The corresponding levers may be the levers in the toggles which are connected to the respective first elements.

The pivot connection of each toggle to the respective second element may lie forward of the pivot connection of the toggle to the first element with the mechanism in its first position. The pivot connection of each toggle to the respective second element may lie forward of the central pivot of the front lever.

The mechanism may further include an extendable foot rest mechanism connected between the elements, adjacent the front ends thereof, for extension as the second element moves from its first position to its second position.

In any of the above cases the geometry of the mechanism may be such that the movement of the first cross member, as the mechanism moves from the first position to the second position, is substantially horizontal whilst the associated movement of the second element is substantially vertical.

Although the invention has been defined above it is to be understood that it includes any inventive combination of the features set out above or in the following description.

The invention may be performed in various ways and a specific embodiment will now be described in reference to the accompanying drawings, in which: Figure la is a view from above of a reclining mechanism in its second position; Figure 1b is a view from below of the mechanism in its first position; Figure 2 is a side view of the mechanism corresponding to Figure lb; Figure 3 is a side view of the mechanism in its fully reclined or third position; and Figure 4 is a diagrammatic side view of the levers incorporated in the mechanism showing their positions in the first, second and third positions.

Existing reclining mechanisms essentially comprise two side elements each including a chair frame element 11, a seat frame element 12, interconnecting rear and front levers 13 and 14 and one half of the foot rest mechanism generally indicated at 15. The operation of these side mechanisms is generally well understood, but put briefly elements 11,12 and levers 13 and 14 form a four bar linkage which allows horizontal movement of the seat element 12 relative to the chair element 11 by rotation about pivots D, N, H and G and vertical movement of the front end of the seat element 12 by virtue of the fact that lever 14 is formed as a toggle with one end pivoted at C. It will also be noted that pivots H and G are vertically off-set giving some vertical movement during normal four bar linkage movement.

Thus, as can be best seen in Figure 4, the side mechanisms can move from a first position, designated with the numeral 1, to a second position, designated by the numeral 2, and a third position, designated by the numeral 3. Essentially the off-set of the pivots G and H gives the inclination for the reclining of the seat in position 2, whilst the opening of lever 14 provides the lifting for the fully reclined or third position.

Turning to the present invention, the Applicant has introduced respective toggle mechanisms 16 between the chair elements 11 and seat elements 12 in each side mechanism 10.

As the toggle opens it moves the side mechanisms from the first position to the second position and further opening causes the side mechanisms 10 to enter the third position.

The opening movement of the toggle 16 is achieved by means of a cross member 17, which is mounted between the toggle element 16. This is achieved by creating the lower levers 18 of the toggles 16 as inverted generally isosceles triangular members with the lower pivot A at the apex, the central toggle pivot K at the forward corner of the base and the cross member at the other corner of the base of lever 18. Because the cross member is thus off-set from the pivot K its forward or backward movement causes pivoting at the pivot K and hence closing or opening of the toggle 16.

The cross member 17 carries a trunnion 19 for receiving one end of a linear actuator not shown. A corresponding cross member 20 extends between the rear ends of the chair elements and has a corresponding trunnion 21 for the other end of the actuator.

It will thus be seen that the reclining mechanism can be moved between positions 1 and 3, through position 2, simply by extending and contracting the linear actuator and hence an effective system of motorisation is achieved. The geometry illustrated provides a particularly compact arrangement which enables an actuator of sufficient length to be contained within the envelope of the chair.

The use of the toggle and cross member combination has another significant advantage in that it allows substantially horizontal movement of the cross member, during movement from position 3 to position 2, whilst allowing controlled substantially vertical movement of the seat element relative to the chair element with the result that the well known dropping or "clunking" feature of existing mechanisms is removed.

It should be noted that this feature exists whether or not the mechanism is motorised and so the construction is advantageous even when operated by the users weight and pull.

Claims (13)

1. A reclining chair mechanism of the type described characterised in that the mechanism includes: a) a toggle for each side mechanism interconnecting the elements adjacent the second lever, and b) a cross member interconnecting the toggles, where by, by movement of the cross member in a sense to open the toggles, the second element can be moved from its first position to its second position and, subsequently, to its third position.

2. A mechanism, as claimed in claim 1 further including a further cross member extending between the first elements adjacent the first levers.

3. A mechanism as claimed in claim 2 further comprising a linear actuator mounted between the cross members.

4. A mechanism as claimed in claim 3 wherein the cross members have respective trunnions for pivotably supporting respective ends of the actuator.

5. A mechanism as claimed in any one of the preceding claims wherein the first cross member is connected to the corresponding lever of each toggle at a location spaced from a line joining the pivots of the respective corresponding lever.

6. A mechanism as claimed in claim 5 wherein each corresponding lever is generally in the form of an inverted isosceles triangle with one pivot at the apex, and a pivot and the cross member at respective corners of the base.

7. A mechanism as claimed in claim 5 or claim 6 wherein the corresponding levers are the levers in the toggles which are connected to the respective first elements.

8. A mechanism as claimed in any one of the preceding claims wherein the pivot connection of each toggle to the respective second element lies forward of the pivot connection of the toggle to the first element with the mechanism in the first position.

9. A mechanism as claimed in claim 8 wherein the pivot connection of each toggle to the respective second element lies forward of the central pivot of the front lever.

10. A mechanism as claimed in any one of the preceding claims further including an extendable foot rest mechanism connected between the element adjacent the front ends thereof for extension as the second element moves from its first position to its second position.

11. A mechanism as claimed in any one of the preceding claims wherein the geometry is such that the movement of the cross member, as the mechanism moves from the third position to the second position, is substantially horizontal, whilst the corresponding movement of the second element is substantially vertical.

12. A reclining chair mechanism substantially as herein before defined with reference to the accompanying drawings.

13. A reclining chair incorporating a mechanism as claimed in any one of the preceding claims.