Wei Li

US Patent:

60658037, May 23, 2000

Filed:

May 5, 1999

Appl. No.:

9/305554

Inventors:

Wei Guang Li - Clemmons NC
Laurence V. O'Leary - Pittsboro NC

Assignee:

L&P Property Management Company - South Gate CA

International Classification:

A47C 300

US Classification:

2973013

Abstract:

A tilt control apparatus is provided for use on a chair having a base and a backrest, and includes a center retainer from which a pair of torsion bar segments protrude. A tubular outer casing is received over each torsion bar segment and is affixed to the center retainer, and an end bar retainer is received on the distal end of each torsion bar segment for rotation therewith. A structure is provided for restricting axial and rotational movement of the end retainers relative to the outer casings, holding the end retainers in place on the apparatus and permitting the torsion bar segments to be pre-torqued, if desired. The center retainer and outer casings are adapted for securement together to either the base or backrest of the chair, and the end retainers are adapted for securement to the other such that the backrest can be tilted relative to the base between an upright position and a tilted position, the torsion bar segments biasing the end retainers in a direction adapted to return the backrest to the upright position. A method of assembling a tilt control apparatus is also provided, wherein the torsion bar segments are pre-torqued to set the magnitude of the biasing force exerted on the backrest.