Patent ID: 6213551
Filing Date: 2001-04-10
Classification: A47C

Abstract:
A chair, comprising:a base for supporting the chair on a floor;a seat positioned generally above said base and supported for movement thereon by a linkage connection;a locking mechanism operable to immobilize said seat relative to said base, said locking mechanism including:a) a retaining member mounted to said base;b) an elongate member pivotally mounted to said seat at a first pivot axis, said elongate member defining an array of teeth spaced along its length, said elongate member in use extending generally in a direction of movement of said seat relative to said base and being of such length that throughout at least a major part of said movement, said retaining member lies in register with said array of teeth; andc) an actuating mechanism selectively operable to effect a pivotal movement of said elongate member towards said retaining member to lock said seat with respect to said base, said actuating mechanism including:i) a lever mounted to said seat on one side thereof;ii) an operating linkage controlled by said lever, said operating linkage including first and second struts having adjacent ends that are pivoted together on a second pivot axis, a second end of said first strut being pivoted on a third pivot axis to said elongate member, and a second end of said second strut being pivotally mounted on a fourth pivot axis on said seat, said struts being movable in respective planes substantially normal to said first pivot axis between a retracted position wherein said struts are folded at an acute angle about said second pivot axis and said teeth are spaced above said retaining member, and an extended position wherein said struts are extended so as to be substantially aligned with each other and a tooth of said elongate member lies in locking engagement with said retaining member.