Knob

Claim 1

A one-piece, molded knob for use in turning a control shaft having a leading end of generally ''''D'''' shaped cross-section comprising a generally flat outer surface and a generally arcuate outer surface, said knob comprising a manually engageable head portion and a tubular stem integrally formed with and projecting outwardly from said head portion, said stem comprising an outer stem wall which at least partially defines a longitudinally extending chamber for receiving a portion of the leading edge of the control shaft, said chamber being of a generally D shaped cross-section being defined by a generally flat inner surface and a generally arcuate inner surface, retainer means integral with said outer stem wall for retaining the control shaft in said chamber, said retainer means comprising surface means extending from said arcuate inner surface and inclined in the direction of insertion of the shaft into said chamber, said retainer means located in a position for engagement with the leading end of the control shaft for resiliently deflecting a portion of said outer stem wall radially outwardly as the control shaft is inserted into said chamber and for pressing the control shaft against a longitudinally extending inner surface of said chamber under the influence of the resiliently deflected portion of said outer stem wall, said outer stem wall adjacent to said retainer means being recessed and relatively thinner than the adjacent portions of said outer stem wall.