Chair
First Claim
1. A chair comprising a seat, a back, a four bar linkage, said linkage including a base, said seat forming a second link of said linkage, said linkage including a third link having one end portion pivotably connected with a rear portion of said base and an opposite end portion pivotably connected with a rear portion of said seat, a fourth link having a first end portion pivotably connected with a forward portion of said base and a second end portion pivotably connected with a forward portion of said seat, and means for mounting and fixing said back to said fourth link for pivoting movement together with said fourth link about said pivotable connection between said fourth link and said base.
4 Assignments
0 Petitions
Accused Products
Abstract
A chair of the tilting type which includes a base, a seat and back, with the base pivotally supporting the seat with two opposite non-parallel links of the four bar non-parallel linkage, with one of the opposite links extending to support the back and also being formed to provide an arm rest. The four bar linkage is duplicated on each side of the chair by forming the two opposite non-parallel links or cranks from the upturned ends of the tubes which pass through the base in parallel but vertically offset fashion, the base thus forming the fixed bar of the linkage with its opposite bar or coupler being formed by the seat. A spring within the base is operative on one of the tubes to urge the chair to an upright position. The tubes are pivotally connected to the seat and one of the tubes extends and is fixedly connected to the back in a manner to emphasize the isolated and separate appearance of the seat and back. With the above construction the seat and back both tilt in their proper natural body support positions but in a respective ratio of about 1 to 3. The chair thus obviates some of the problems of prior chairs where only the back tilts or both the seat and back tilt as a unit.
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Citations
16 Claims
- 1. A chair comprising a seat, a back, a four bar linkage, said linkage including a base, said seat forming a second link of said linkage, said linkage including a third link having one end portion pivotably connected with a rear portion of said base and an opposite end portion pivotably connected with a rear portion of said seat, a fourth link having a first end portion pivotably connected with a forward portion of said base and a second end portion pivotably connected with a forward portion of said seat, and means for mounting and fixing said back to said fourth link for pivoting movement together with said fourth link about said pivotable connection between said fourth link and said base.
Specification