# US 10,945,529 B2 · Chair

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- Number: US 10,945,529 B2
- Document ID: US10945529B2
- Status: Granted
- Kind: B2
- Application number: 16/483,453
- Filed: 2018-02-05
- Published: 2020-01-30
- Granted: 2021-03-16
- Earliest claimed: 2017-02-03
- Assignees: Zhejiang Sunon Furniture Manufacture Co., Ltd.
- Applicants: Zhejiang Sunon Furniture Manufacture Co., Ltd.
- Inventors: Ruarc O'Boyle; Peter Horn
- Web page: https://patentgrep.com/patent/US10945529B2

## CPC

- A47C 7/405: {with double backrests}
- A47C 7/44: with elastically-mounted frame
- A47C 1/03255: {with a central column, e.g. rocking office chairs}
- A47C 1/03279: {of torsion type}
- A47C 1/035: in combination with movably-coupled seat and back-rest
- A47C 7/443: {with coil springs}
- A47C 7/444: {of torsion type}
- A47C 7/445: {with bar or leaf springs}
- A47C 7/4454: {of torsion type}
- A47C 7/448: {with resilient blocks}
- A47C 7/48: of freely-rotatable type
- A47C: CHAIRS; SOFAS; BEDS

## Abstract

A chair includes a seat surface and a laterally pivotable backrest. The backrest is secured to two joints, which have mutually parallel axes of rotation.

## Claims

### Claim 1

A chair comprising a seat surface and a laterally pivotable backrest, wherein:
the backrest is secured to two joints, which have mutually parallel axes of rotation,
the axes of rotation are attached on one side to a common base plate, extend backwards from the base plate at an acute angle (a) with a horizontal plane,
the base plate is detachably attached to the rear end of a chair mechanism which couples the backrest to the seat surface,
the joints are each operatively connected to restoring elements which are torsion springs which act in opposite directions, and
wherein the seat backrest has a frame having a gap in an area between the joints.

### Claim 2 (depends on 1)

The chair according to claim 1, wherein the restoring elements are preloaded with the backrest in an upright position.

### Claim 3 (depends on 2)

The chair according to claim 2, wherein at least one elastic element is positioned in the gap.

### Claim 4 (depends on 3)

The chair according to claim 3, wherein the elastic element is a two-component element made from different elastic plastics.

### Claim 5 (depends on 1)

The chair according to claim 1, wherein at least one elastic element is positioned in the gap.

### Claim 6 (depends on 5)

The chair according to claim 5, wherein the elastic element is a two-component element made from different elastic plastics.

### Claim 7 (depends on 1)

The chair according to claim 1, wherein the torsion springs comprise:
a first torsion spring disposed over one of the mutually parallel axes of rotation, and
a second torsion spring disposed over another of the mutually parallel axes of rotation.

### Claim 8 (depends on 7)

The chair according to claim 7, comprising:
a stop element positioned between the mutually parallel axes of rotation, wherein a limb of each of the first and second torsion springs are braced against the stop element.

### Claim 9

A chair comprising a seat surface and a laterally pivotable backrest, wherein:
the backrest is secured to two joints, which have mutually parallel axes of rotation,
the axes of rotation are attached on one side to a common base plate, extend backwards from the base plate at an acute angle (a) with a horizontal plane,
the base plate is detachably attached to the rear end of a chair mechanism which couples the backrest to the seat surface,
the joints are each operatively connected to restoring elements which are torsion springs which act in opposite directions,
wherein the seat backrest has a frame having a gap in an area between the joints, and
wherein at least one elastic element is positioned in the gap.

### Claim 10 (depends on 9)

The chair according to claim 9, wherein the at least one elastic element is a two-component element made from different elastic plastics.

### Claim 11 (depends on 9)

The chair according to claim 9, wherein the restoring elements are preloaded with the backrest in an upright position.