# US 5,704,689 A · Chair having separable back

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- Number: US 5,704,689 A
- Document ID: US5704689A
- Status: Granted
- Kind: A
- Application number: 08/727,646
- Filed: 1996-10-15
- Granted: 1998-01-06
- Earliest claimed: 1995-02-15
- Inventors: Moung Sook Kim
- Web page: https://patentgrep.com/patent/US5704689A

## CPC

- A47C 7/46: with special, e.g. adjustable {, lumbar region support} profile; "Ackerblom" profile chairs
- A47C 7/405: {with double backrests}
- A47C 7/441: {with adjustable elasticity}
- A47C 7/443: {with coil springs}
- A47C: CHAIRS; SOFAS; BEDS

## Abstract

The back of a chair is divided into a waist support (40) and a shoulder support (50) which are pivotally supported by respective support members (27 and 37) so that they can move freely and individually. The waist support (40) and the shoulder support (50) can move back and forth freely and independently against resilient resistance and their inclinations can be adjusted separately and manually. The waist support (40) always supports the waist while keeping close contact therewith and the shoulder support (50) supports the shoulder while keeping close contact therewith. Therefore, even when one uses the chair for a long time, the occupants comfort is assured as no load is applied to the waist.

## Claims

### Claim 1

A chair comprising a seat plate and a back support extending upwardly at a rear portion of said seat plate to engage and support a back of a seat occupant, said back support including a waist support engaging and supporting a waist area of the back of the seat occupant and a shoulder support engaging and supporting a shoulder area of the seat occupant, said shoulder support being separate from and independent of said waist support, said shoulder support being located above and generally in alignment with said waist support, a waist support member supporting said waist support, a shoulder support member supporting said shoulder support, said waist support member extending forwardly under said seat plate and terminating in a forward end pivotally connected to said seat plate, said shoulder support member extending forwardly under said seat plate independently of said waist support member, said shoulder support member terminating in a forward end pivotally connected to said plate to enable independent pivotal movement of said support members, and an independent resilient structure connecting said seat plate to each of said support members, each independent resilient structure being independently adjustable to independently control the resilient resistance to pivotal movement of each of the support members, the waist support and the shoulder support.

### Claim 2 (depends on 1)

The chair as defined in claim 1 wherein each of said support members includes an upwardly extending plate at a rearward end thereof, said upwardly extending plate on said shoulder support member extending above and being spaced rearwardly from the upwardly extending plate on the waist support member and supportingly connected to said shoulder support, said upwardly extending plate on the waist support member being shorter than and spaced from the upwardly extending plate on said shoulder support member and supportingly connected to said waist support to enable relative pivotal movement between the waist support and shoulder support without interference.

### Claim 3 (depends on 2)

The chair as defined in claim 2 wherein each of said resilient structures includes a depending threaded member rigidly connected to said seat plate and extending downwardly through an aperture in one of said support members, a coil spring mounted on each of said threaded members and a threaded knob mounted on a lower end of each threaded member to independently control compressive force on each coil spring thereby independently controlling the resilient resistance to pivotal movement of said shoulder support and said waist support.