GB2312832A - Variable geometry chair - Google Patents

Abstract

A variable geometry seat 10 connected to frame 12 by hinged legs 11 and 12 and retained in the upright chair format (Fig. l) by virtue of the normally extended spring damper or gas strut 15. The whole converting to a lowered and reclined position (Fig 2) by application of upper-body back pressure by the seated user and the resulting mass centre shift plus moment arm reaction overiding the spring damper or gas struts. Return to the upright chair position is achieved by the user easing upper-body pressure and the resulting mass centre shift plus reduced moment arm being overidden by the spring damper or gas strut.

Description

VARIABLE GEOMETRY CHAIR The invention relates to a variable posture chair which converts from a conventional upright seat position to a low level reclined position.

Variable posture chairs and recliners are well known and exist in many formats where the adjustments for posture are undertaken manually or by user controlled mechanical drive.Typical examples consist of garden recliners, variable posture chairs for the disabled and infirm, dentists and barbers chairs.

According to the present invention there is provided a conventional upright chair which can be transformed into a low level recliner by body movement of the seated user. Restoring the recliner to the upright chair position is also achieved by body movement.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which; Figure 1 shows in perspective the invention in the upright chair position.

Figure 2 shows in perspective the invention in the low level reclined position.

Figures 3a-b-c-d-e show in side elevation the variable geometry and how this is controlled by the user.

Referring to the drawing the invention consists of a seat 10 supported by front legs 11 and back legs 12.

The back of the chair 13 consists of a rigid extension secured to legs 11. The legs 11 and 12 are hinged to the seat 10 such that they are able to swing forward and establish a position which is almost parallel to the underside of the seat.

The lower end of the legs are secured by hinges to base frame 14.

A normally extended spring damper or gas strut 15 is connected by pivots to legs 12 and and frame 14 such that the whole structure is normally retained in the chair configuration. (FIG. 1) In order to convert the chair from the upright into the reclined position (FIG.2), the seated user leans back and applies pressure to the chair back 13 therby overiding the damper or gas strut 15. The chair will slowly descend into the reclined position (Figures 3a-b-c-d-e refer). Return to the upright position is achieved by the user leaning forward and reducing pressure against the back of the chair, thereby being overidden by the spring-return action of the damper or gas strut 15.

The chair can be locked in both the upright and reclined positions by a catch or similar means (not shown).

Claims (5)

1. A variable geometry chair which can be converted from an upright position into a reclined position by its seated user.

2. A variable geometry chair as defined in claim 1, wherein the chair adopts a reclined position as determined by body shift of its seated/reclined user.

3. A variable geometry chair as defined in claims 1 and 2 where the required geometric position can be adjusted by the user without the user having to be seperated from the chair.

4. A variable geometry chair as defined in claims 1, 2 and 3 where the geometry of the chair is not controlled or powered by external means other than that exherted by the user and by the spring-damper or gas-strut.

5. A variable geometry chair as defined in claims 1,2,3, and 4 where the geometry of the chair is determined by the body pressure and mass centre shift of the seated user.