Variable back adjuster for chairs
AssigneeSteelcase Inc.
InventorsCharles P. Roossien, Brian Chambers, Bruce Hiemstra
Life of this patent
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Abstract
An adjustor for chairs with tilting backs and the like, comprises a threaded spindle connected with the chair back, and a gear wheel threadedly mounted on the spindle. The gear wheel is retained in a housing attached to a relatively stationary portion of the chair, such that when the chair back is tilted, the spindle rotates the gear wheel in the housing. A pawl is shifted into and out of engagement with the gear wheel to selectively lock the chair back in a wide variety of different angular positions.
Claims31
In a chair having a tilting back which pivots relative to a mounting portion of said chair, the improvement of a variable back adjustment mechanism, comprising:
- a first bracket to be mounted on said mounting portion;
- a second bracket pivotally secured to said first bracket in overlying relationship thereto and to be operatively connected to said chair back;
- a threaded spindle having one end thereof connected with one of said first and second brackets at a position on said one bracket spaced from said pivotal connection;
- a gear wheel threadedly mounted on said spindle;
- a gear wheel housing connected with the other of said first and second brackets spaced from said pivotal connection, and rotatably retaining said gear therein, whereby tilting said chair back pivots said two brackets and translates said spindle axially through said gear wheel, thereby rotating said gear wheel in said housing;
- a pawl movably connected with said chair, and positioned to selectively engage said gear wheel to positively prevent rotation of said gear wheel with respect to said spindle;
- means for shifting said pawl into and out of engagement with said gear wheel between locked and unlocked positions respectively, whereby said chair back can be locked in a plurality of different angular positions.
A variable back adjustment mechanism for a chair having a tilting back which pivots relative to a mounting portion of said chair, said adjustment mechanism comprising:
- a first bracket to be mounted on said mounting portion;
- a second bracket pivotally secured to said first bracket in overlying relationship thereto and to be operatively connected to said chair back;
- a threaded spindle having one end thereof adapted for connection with one of said first and second brackets at a position on said one bracket spaced from said pivotal connection;
- a gear wheel threadedly mounted on said spindle;
- a gear wheel housing adapted for connection with the other of said first and second brackets at a position on said other bracket spaced for said pivotal connection, and rotatably retaining said gear therein, whereby tilting said chair back pivots said two brackets and translates said spindle axially through said gear wheel, thereby rotating said gear in said housing;
- a pawl movably connected with the other of said chair back and said mounting portion, and positioned to selectively engage said gear wheel to positively prevent rotation of said gear wheel with respect to said spindle;
- means for shifting said pawl into and out of engagement with said gear wheel between locked and unlocked positions respectively for locking said chair back in a plurality of different angular positions.
Dependencies are inferred from the claim text.