Handle assembly for chair control mechanism

• US 5,152,580 A
• Filed: 10/15/1991
• Issued: 10/06/1992
• Est. Priority Date: 06/21/1990
• Status: Expired due to Term

• Current Assignee: Leggett & Platt Incorporated
• Original Assignee: Faultless-Doerner Manufacturing Incorporated
• Inventors: Stumpf, William S.
• Primary Examiner(s): Dorner, Kenneth J.
• Assistant Examiner(s): Bonifanti, J.
• Application Number:
  US07/774,651
• Time in Patent Office: 357 Days
• Field of Search: 297/302-305, 16/118, 16/121, 16/DIG. 24, 74/553, 74/557
• US Class Current: 297/303.5
• CPC Class Codes: A47C 3/026 with central column, e.g. rocking office chairs; Tilting chairs
• CPC Class Codes: A47C 7/441 with adjustable elasticity
• CPC Class Codes: A47C 7/443 with coil springs
• CPC Class Codes: B60N 2/90 Details or parts not otherwise provided for
• CPC Class Codes: Y10T 74/2084 Knob or dial
• CPC Class Codes: Y10T 74/20864 Handles

Abstract

A chair control mechanism of the type having a seat support member pivotally mounted on a leg mounting member, and a spring loaded adjustment mechanism for controlling the pivotal movement of one member with respect to the other. The adjustment mechanism includes a handle mounted on an adjustment screw for movement therealong to compress or allow extension of the compression spring. A nut is threadedly mounted on the adjustment screw and serves to retain the members, adjustment screw and spring in an assembled configuration during shipping to and assembly of a chair by a chair manufacturer. A hand wheel is provided for attachment to the nut after the control mechanism has been assembled and installed in a chair. The hand wheel has a body of plastics material in which a seat formed which is proportioned to accommodate and adapted to cooperate with the nut such that when the nut is seated therein, rotation of the hand wheel will cause rotation of the nut with respect to the adjustment screw. The seat also cooperates with the nut to prevent removal of the nut therefrom. The body of plastics material is sufficiently flexible to permit resilient deformation of the seat to admit the nut thereto.

Claims

1. In a chair control mechanism of the type having a seat support member pivotally mounted on a leg mounting member, and means for controlling the pivotal movement of said members with respect to one another including an adjustment screw, a compression spring and a handle mounted on the adjustment screw for movement therealong to compress or allow extension of the compression spring, the improvement wherein the handle comprises:

a) a nut that is threadably mounted on the adjustment screw and serves to retain said adjustment screw and compression spring to said seat support member and leg mounting member in an assembled configuration, during shipping to and assembly of a chair by a chair manufacturer, the nut having a plurality of appreciably flat side faces and having an annular recess, and

b) a hand wheel comprising a body of a deformable and resilient plastic material having a sleeve formed therein which is proportioned to receive and cooperate with said nut, said sleeve of said hand wheel having a bore extending completely therethrough for receiving said nut, the sleeve having a plurality of appreciably flat side faces bordering the bore, at least some of which are located adjacent some of the side faces of said nut to prevent substantial rotational movement of the nut with respect to the hand wheel and arranged to bear against at least a portion of the side faces of the head of the nut during rotation of the hand wheel to permit torque forces to be transferred from the hand wheel to the nut such that when the nut is seated within said sleeve, rotation of the hand wheel will cause rotation of the nut with respect to the adjustment screw, the hand wheel provided with detent means projecting into the bore from said sleeve, the hand wheel, the sleeve and the detent means being of unitary construction, the detent means being shaped and proportioned so that during assembly, the hand wheel may be pushed over the nut so that the nut is received by the bore in the sleeve and the detent means resiliently deforms over the head portion of the nut until the detent means extends into the annular recess of said nut thereby preventing axial movement of the hand wheel relative to the nut said detent means by itself not restricting rotational movement of the hand wheel relative to the nut.

2. A control mechanism according to claim 1 wherein said detent means comprises at least two projections each located on a different face bounding said bore, and wherein said nut is provided with a tubular portion which extends axially from the head portion, the annular recess located in said tubular portion and being circumferentially disposed thereabout.