Chair tilting mechanism and a chair incorporating such a mechanism

Abstract

A chair tilt mechanism comprising a mechanism support adapted for connection to the seat of a chair and including first means for connection to a chair base and which are pivoted to said mechanism support, second means for connection to a chair back support pivoted to said first means and resilient biasing means which extend between the pivot between the first and second means and the mechanism support, movement of the mechanism support against the biasing causing relative angular movement between the first and second means and relative angular movement of the mechanism support about the pivot between the first means and the mechanism support.

1 . A chair tilt mechanism comprising a mechanism support adapted for connection to the seat of a chair and including first means for connection to a chair base and which are pivoted to said mechanism support, second means for connection to a chair back support pivoted to said first means and resilient biasing means which extend between the pivot between the first and second means and the mechanism support, movement of the mechanism support against the biasing causing relative angular movement between the first and second means and relative angular movement of the mechanism support about the pivot between the first means and the mechanism support.  
     
     
         2 . A chair tilt mechanism as claimed in  claim 1  in which said first and second means are provided respectively by the arms of a toggle joint, said resilient biasing means acting on the joint pivot.  
     
     
         3 . A chair tilt mechanism as claimed in  claim 1  or  claim 2  in which said resilient biasing means are provided by a block or blocks of resilient material.  
     
     
         4 . A chair tilt mechanism as claimed in  claim 3  in which the resilient material is rubber or a synthetic polymeric material.  
     
     
         5 . A chair tilt mechanism as claimed in  claim 3  or  claim 4  in which the block or blocks are deformed from an initial shape during installation so that they are pre-stressed when in position ready for use.  
     
     
         6 . A chair tilt mechanism as claimed in any one of the preceding claims including means for locking the mechanism support to the first means.  
     
     
         7 . A chair incorporating a tilt mechanism as set forth in any one of the preceding claims.