GB2313048A

GB2313048A - Three-way reclining mechanism

Info

Publication number: GB2313048A
Application number: GB9709836A
Authority: GB
Inventors: Richard John Hale
Original assignee: SEMINAR COMPONENTS
Current assignee: SEMINAR COMPONENTS
Priority date: 1996-05-15
Filing date: 1997-05-15
Publication date: 1997-11-19
Anticipated expiration: 2017-05-15
Also published as: GB2313048B; GB9709836D0

Abstract

When a recliner is in the seated position a locking plate 8 is in the clockwise rotated position where a lock pin 4 is housed in a slot and a lever SU6 rests on the pin 4 at S. The force of the body mass is to the right of the hinge point S and the forces on a front linkage NMJ are to the right of point M, creating a closing effect. Forces exerted at 7 (the top of a chair back) acting from left to right force the locking hinge plate 8 onto the pin 4. Forces acting from right to left pull the plate 8 upwards and the plate is then held by the pin 4, instead of transmitting the load through linkage RQ and to the drive means. The location of the pin in the slot in the plate 8 relieves load on the drive means under abnormal loading conditions on the chair.

Description

Three-way Reclining Mechanism.

Reclining mechanisms, whether manually or mechanically driven, consist of metal bars and linkages whereby a seat, backrest and footrest are pivotally connected by the bars and linkages. The methods of mounting the seat to the recliner fall into 2 categories.

1. The securing of the seat mounting bracket to the outside of the seat frame which has a height 2 to 3 times the width of the lateral members. This type of seat frame will be referred to as the high frame.

2. The securing of a seat frame by mounting a bracket at the front and rear of the seat frame. The seat frame is secured from below and the section of the frame has a width 2 to 3 times the depth. This type of seat frame will be referred to as the flat frame.

The choice of mounting and the type of seat frame is dictated by the recliner mechanism chosen.

Manual mechanisms, if acted upon by an external force such as a person sitting on the footrest, will cause the recliner to collapse to the seated position. If a force is exerted on the backrest, such as by pushing the chair forward, this will also cause the recliner to collapse. In the case of motorised systems the recliner is prevented from collapsing by the actuator or drive means. The result of the restraint is to cause damage to the drive means, if force is applied in the manner described.

Motorised recliners have either a flat frame or a high seat frame but cannot be used for both. Motorised recliners using the high seat frame are driven on the inside of the seat frame, being dependent on the seat frame for the transfer of drive forces from the motor.

According to the invention there is provided a multiple position reclining mechanism for a chair, wherein the seat frame and the back rest and possibly also a foot rest are interconnected by a linkage arrangement allowing movement between desired positions, and including a pin or like member mounted on the chair base and a locking plate pivotally attached to the seat frame and movable parts of the linkage arrangement, the locking plate having a bearing face with which the pin engages, whereby the pin is at least partially captive in one position, so that external forces applied to the chair assembly are borne by the locking plate acting on the pin.

In one arrangement the bearing face may be an elongated extension from a notch which captivates the pin in said one position. Alternatively the bearing face could form part of a slot within which the pin is captivated. The interengagement of the bearing face and/or notch on the pin transfers any external load applied to the chair to the chair base, rather than putting an undue load on the drive means used to move the chair assembly between its various positions.

The invention may be performed in various ways and a preferred embodiment will now be described, by way of example, with reference to the accompanying drawings, in which:- Figures 1, 2 and 3 illustrate diagrammatically a reclining chair mechanism of this invention, respectively in the positions of normal seating, intermediate recline and full recline; Figure 4 is a side view of the mechanism shown in Figure 1 in more detail; and Figure 5 illustrates a modification to part of the assembly shown in Figure 1.

When the recliner is in the seated position (Figure 1) a locking plate 8 is in the clockwise rotated position where a lock pin 4 is housed in a slot and a lever SU6 rests on the pin 4 at S. The force of the body mass is to the right of the hinge point S and the forces on a front linkage NMJ are to the right of point M, creating a closing effect. As the recliner is driven by drive means 3,2 through a linkage RQ, movement of a bracket XTNRK is to the left, causing anti-clockwise rotation of linkages NMJ and ST (locking plate 8). Forces exerted at 7 (the top of a chair back) acting from left to right force the locking hinge plate 8 onto the pin 4. Forces acting from right to left pull the plate 8 upwards and the plate is then held by the pin 4, instead of transmitting the load through linkage RQ and to the drive means.

Further motion of the recliner achieves the first recline position as in Figure 2. At this point the lever SU6 rises and lever 5UM rotates in an anti-clockwise direction and the lock lever 8 moves off the pin 4. Loads acting at 7 downwards create a sympathetic compressive load on the drive means. Loads exerted on the footrest ABC, other than the weight of the user's legs, create an adverse load condition in the drive means but are borne by the lock plate 8 abutting against the pin 4.

The provision of such a locking device has the result that, when external forces are applied, those forces are borne by the locking device instead of by the driving device, hence reducing the potential of damage.

A drive plate 1Q2 is mounted such that the drive linkage RQ, when connected to the seat frame XTNRK at R between the points NK, simultaneously satisfies the drive conditions necessary for the three positions of seated, reclined and full reclined (Figure 3) whilst still maintaining sympathetic angles of action to drive the system. The hinge points X, T, N, R and K are situated on the outside of the seat frame enabling the use of either a flat or deep seat frame section. The provision of a seat frame mounting bar that can be used for either a flat or high frame and the drive means attached to it make it independent of the choice of seat frame.

The interconnection of the various linkages can be seem additionally from Figure 4. This shows also the mounting points 9 and 10 for a drive motor used to move the mechanism between the three conditions shown in Figures 1 to 3. The seat frame is shown at 11, the backrest at 12 and the footrest at 13. The linkages used to drive the footrest 13 outwardly are shown at 14.

An arrangement where the pin 4 is captivated within a slot is shown in the accompanying Figure 5. The shape of the slot in the lever 8 comprises 3 main parts. Arc AA provides for capture during the footrest operation, Arc BB provides for the full recline capture, and Arc CC provides for the transition between the two modes. The slot geometry over the Arc lengths AA & BB produces a parallel path between the pin and the slot face. The Arc CC produces a specifically non-parallel path to ensure a smooth transition whilst still maintaining adequate protection to the drive means.

Claims

1. A multiple position reclining mechanism for a chair, wherein the seat frame and the back rest and possibly also a foot rest are interconnected by a linkage arrangement allowing movement between desired positions, and including a pin or like member mounted on the chair base and a locking plate pivotally attached to the seat frame and movable parts of the linkage arrangement, the locking plate having a bearing face with which the pin engages, whereby the pin is at least partially captive in one position, so that external forces applied to the chair assembly are borne by the locking plate acting on the pin.

2. A mechanism according to Claim 1, wherein the bearing face is an elongated extension from a notch which captivates the pin in said one position.

3. A mechanism according to Claim 1, wherein the bearing face forms part of a slot within which the pin is captivated.

4. Any novel combination of features of a reclining mechanism for a chair substantially as herein described with reference to the accompanying drawings.