Torsion bar chair control

Claim 2

A chair control comprising: a seat mount having a pair of horizontally spaceD surfaces receivable on a chair seat, said surfaces being disposed at upper margins of horizontally spaced walls, with the lower marginal portions of said walls being bridged by a bridging portion; a torsion bar; first load transmitting means between one end of said torsion bar and said mount; a post; second load transmitting means between the other end of said torsion bar and said post; said seat mount being sufficiently rigid to transfer seat tilting loads equally from said surfaces to said first load transmitting means; said first load transmitting means including a first tube beginning near one of said walls and extending away from said walls in a first direction: a first torque arm extending radially from said first tube to a point under one of said surfaces; adjustment means associated with said arm and having a hand grip thereon to facilitate adjustment, a portion of said adjustment means bearing on said mount above said point; said second load transmitting means including a second tube beginning at said one wall and extending through the other of said walls; said walls being pivotally mounted on said second tube for rocking thereon.

Claim 3

The chair control of claim 1 wherein: said first tube has an end formed to nonrotatably receive one end of said torsion bar, and said second tube has an end formed to nonrotatably receive the other end of said torsion bar.

Claim 4

The control of claim 1 wherein: first and second bushings are received in apertures in said seat mount walls and are received on said second tube to provide bearings for rocking of said seat mount on said tube, said bushings having radially extending flanges thereon providing axial bearings between said seat mount walls and said post mount walls; said control further comprising a third bushing received in an end of said second tube adjacent said one wall and received in an end of said first tube adjacent said one wall, facilitating relative rotation between said first and second tubes on their longitudinal axis as said adjustment means are adjusted and as said seat mount is rocked on said second tube, the turning and rocking being resisted by torsional resilience of said torsion bar.

Claim 5

The chair control of claim 1 and further comprising: a post mount having a pair of horizontally spaced walls with a bridge portion bridging the space between said walls, said second tube extending through said walls and supported thereby, means preventing rotation of said second tube in said post mount walls, and means limiting the available degree of rocking of said seat mount on said post mount.

Claim 6

The chair control of claim 4 wherein: said means preventing rotation of said second tube in said post mount include a longitudinally extending slot in said second tube, and a pawl received in said slot and extending radially into engagement with said bridge portion of said post mount.

Claim 7

A chair control comprising: a seat mount connectable to a chair seat and having a pair of horizontally spaced walls fixed with respect to each other by bridge means independent of a chair seat; a post mount; a torsion bar; first load transmitting means between one end of said torsion bar and said seat mount; second load transmitting means between the other end of said torsion bar and said post mount; said first load transmitting means include a first tube and said second load transmitting means include a second tube aligned endwise with said first tube; said post mount including horizontally spaced parallel upstanding arms; said second tube extending through aligned apertures in said arms and projects to one side of said post mount; first and second bushings horizontally spaced and located on said first tube by said arms of said post mount; said seat mount having first and second spiders received respectively on said first and second bushings, said spiders being rigidly connected together by saId bridge means extending therebetween; and said first tube having an axis colinear with the axis of said second tube, said first tube being in load transmitting relationship to one of said spiders and projecting therefrom opposite said second tube.

Claim 8

A chair control comprising: a seat mount connectable to a chair seat and having a pair of horizontally spaced walls fixed with respect to each other by bridge means independent of a chair seat; a post mount; a torsion bar; first load transmitting means between one end of said torsion bar and said seat mount; second load transmitting means between the other end of said torsion bar and said post mount; said first load transmitting means include a first tube and said second load transmitting means include a second tube aligned endwise with said first tube; said post mount including horizontally spaced parallel upstanding arms; said second tube extending through aligned apertures in said arms and projects to one side of said post mount; first and second bushings horizontally spaced and located on said first tube by said arms of said post mount; said seat mount having first and second spiders received respectively on said first and second bushings, said spiders being rigidly connected together by saId bridge means extending therebetween; and said first tube having an axis colinear with the axis of said second tube, said first tube being in load transmitting relationship to one of said spiders and projecting therefrom opposite said second tube.

Claim 9

The chair control of claim 6 wherein: said torsion bar extends through said tubes and has opposite end portions of noncircular cross section, the distal end of said first tube being crimped to fittingly receive one of said bar end portions, and the distal end of said second tube being crimped to fittingly receive the other end portion of said bar.