# US 8,740,298 B2 · Convertible chair

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- Number: US 8,740,298 B2
- Document ID: US8740298B2
- Status: Granted
- Kind: B2
- Application number: 13/370,659
- Filed: 2012-02-10
- Published: 2012-11-01
- Granted: 2014-06-03
- Earliest claimed: 2011-02-10
- Assignees: Purdue Research Foundation
- Applicants: Leah Kenttamaa-Squires; Kyle Amick
- Inventors: Leah Kenttamaa-Squires; Kyle Amick
- Web page: https://patentgrep.com/patent/US8740298B2

## CPC

- A47C 7/006: {with castors}
- A47C 1/035: in combination with movably-coupled seat and back-rest
- A47C 4/46: of adjustable type (A47C4/48 takes precedence)
- A47C 13/00: Convertible chairs, stools or benches (step-stools requiring conversion between the step and seat functions A47C12/02)
- A47C: CHAIRS; SOFAS; BEDS

## Abstract

A convertible chair with upright and reclined configurations is disclosed. Embodiments of the invention include a chair that collapses to form a dolly and expands to form a chair with upright and reclined seating configurations. Alternate embodiments include a base connected to a seat with a four bar linkage. In still further embodiments, one side of the four bar linkage is extended outside the pivoting joints, the extended portion being pivotally and slidingly engaged with the base. In other embodiments, the chair is configured to maintain the occupant's center of mass near the primary weight supporting pivot linkage.

## Claims

### Claim 1

A chair, comprising:
a seat including four seat members pivotally connected to one another at four seat pivot locations, the four seat pivot locations forming the vertices of a four bar linkage;
a base pivotally connected to the seat at two base pivot locations, one of the base pivot connections being selectively securable to one of the four seat members at two or more locations along the length of the seat member; and
two dolly wheels connected to the seat member to which the base pivot connection selectively secures.

### Claim 2 (depends on 1)

The chair of claim 1, wherein the seat pivot locations are located at positions different from the base pivot locations.

### Claim 3 (depends on 1)

The chair of claim 1, wherein the base is pivotally connected to two seat members.

### Claim 4 (depends on 3)

The chair of claim 3, wherein one base pivot location is positioned on or inside the quadrilateral formed by the four seat pivot locations.

### Claim 5 (depends on 4)

The chair of claim 4, wherein one base pivot location is positioned outside the quadrilateral formed by the four seat pivot locations.

### Claim 6 (depends on 3)

The chair of claim 3, wherein one base pivot location is positioned outside the quadrilateral formed by the four seat pivot locations.

### Claim 7 (depends on 1)

The chair of claim 1, wherein the four seat members are rigid.

### Claim 8 (depends on 1)

The chair of claim 1, wherein the distances between the four seat pivot locations are proportionally equal to approximately 7.1 to 21 to 7.5 to 20.8.

### Claim 9 (depends on 1)

The chair of claim 1, wherein a ratio of the distances between the seat pivot locations on two opposing sides of the four bar linkage are 1.01+/−10% and the ratio of the distances between vertices of the other two opposing sides of the four bar linkage are 1.06+/−10%.

### Claim 10 (depends on 1)

The chair of claim 1, wherein the selectively securable base pivot connection slidingly receives the seat member to which the base pivot connection selectively secures.

### Claim 11 (depends on 1)

The chair of claim 1, further comprising:
an upright configuration for seating a person in an upright position defined by the selectively securable base pivot connection being secured to the one seat member at a first location; and
a reclined configuration for seating a person in a reclined position defined by the selectively securable base pivot connection being secured to the one seat member at a second location different from the first location.

### Claim 12 (depends on 11)

The chair of claim 11, further comprising:
a dolly configuration for rolling movement of a payload supported above a surface with the two dolly wheels and defined by the base pivot connection being secured to the one seat member at a third location different from the first and second locations.

### Claim 13 (depends on 11)

The chair of claim 11, wherein the chair is transitioned from the upright configuration to the reclined configuration by increasing the distance between the seat pivot locations associated with the seat member to which the base pivot connection selectively secures and the selectively securable base pivot connection.

### Claim 14 (depends on 1)

The chair of claim 1, further comprising:
an upright configuration for seating a person in an upright position; and
a reclined configuration for seating a person in a reclined position;
wherein the sides of the quadrilateral formed by the vertices of the four bar linkage have the same length in the upright configuration as in the reclined configuration.

### Claim 15 (depends on 1)

The chair of claim 1, wherein a seat pivot location is collocated with a base pivot location.

### Claim 16

A convertible chair for supporting a person, comprising:
a base;
a seat connected to the base, the seat including a seat bottom and a seat back;
a wheeled member connected to the base;
an upright configuration with the base configured to rest on a support surface with the seat bottom oriented approximately parallel to the support surface and the seat back oriented upright with respect to the support surface;
a reclined configuration with the base configured to rest on the support surface with the seat back oriented approximately parallel to the support surface; and
a dolly configuration with the seat and the base collapsed to form a cargo carrying surface offset from the support surface by the wheeled member;
wherein the wheeled portion of the wheeled member is positioned behind the seat back in the upright configuration, and wherein the wheeled member moves forward when the chair transitions from the upright configuration to the reclined configuration.

### Claim 17 (depends on 16)

The convertible chair of claim 16, wherein the wheeled member forms part of a four bar linkage.

### Claim 18 (depends on 17)

The convertible chair of claim 17, wherein a ratio of the distances between the vertices of two opposing sides of the four bar linkage are 1.01+/−10% and the ratio of the distances between the vertices of the other two opposing sides of the four bar linkage are 1.06+/−10%.

### Claim 19 (depends on 16)

The convertible chair of claim 16, further comprising:
a pivoting linkage connecting the wheeled member and the base, the pivoting linkage slidingly engaging the wheeled member and being adjustable to selectively engage the wheeled member along a length of the wheeled member.

### Claim 20 (depends on 16)

The convertible chair of claim 16, wherein the seat bottom is inclined to raise the occupant's knees above the occupant's hips in the reclined configuration.

### Claim 21 (depends on 20)

The convertible chair of claim 20, further comprising:
a foot rest oriented approximately perpendicular to the support surface in the upright configuration and oriented approximately parallel to the support surface in the reclined configuration.

### Claim 22

A convertible chair for supporting a person, comprising:
a base;
a seat connected to the base, the seat including a seat bottom and a seat back;
a wheeled member connected to the base;
an upright configuration with the base configured to rest on a support surface with the seat bottom oriented approximately parallel to the support surface and the seat back oriented upright with respect to the support surface;
a reclined configuration with the base configured to rest on the support surface with the seat back oriented approximately parallel to the support surface;
a dolly configuration with the seat and the base collapsed to form a cargo carrying surface offset from the support surface by the wheeled member; and
a pivoting linkage connecting the wheeled member and the base, the pivoting linkage slidingly engaging the wheeled member and being adjustable to selectively engage the wheeled member along a length of the wheeled member.

### Claim 23 (depends on 22)

The convertible chair of claim 22, wherein the wheeled member forms part of a four bar linkage.

### Claim 24 (depends on 23)

The convertible chair of claim 23, wherein a ratio of the distances between the vertices of two opposing sides of the four bar linkage are 1.01+/−10% and the ratio of the distances between the vertices of the other two opposing sides of the four bar linkage are 1.06+/−10%.

### Claim 25 (depends on 22)

The convertible chair of claim 22, wherein the wheeled portion of the wheeled member is positioned behind the seat back in the upright configuration, and wherein the wheeled member moves forward when the chair transitions from the upright configuration to the reclined configuration.

### Claim 26 (depends on 22)

The convertible chair of claim 22, wherein the seat bottom is inclined to raise the occupant's knees above the occupant's hips in the reclined configuration.

### Claim 27 (depends on 26)

The convertible chair of claim 26, further comprising:
a foot rest oriented approximately perpendicular to the support surface in the upright configuration and oriented approximately parallel to the support surface in the reclined configuration.