The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 03, 1992
Filed:
Mar. 06, 1991
Frederick S Faiks, Greenville, MI (US);
Craig M Anderson, Kentwood, MI (US);
Daniel R Bischoff, Grand Rapids, MI (US);
Steelcase, Inc., Grand Rapids, MI (US);
Abstract
A controller is provided for seating, and the like, such as chairs of the type that have a stationary base or support, and a back which tilts about a generally horizontal axis with respect to the support. The controller includes an adjustable tension device, and a shared-load arrangement, which readily adapt the chair for different users and various applications. The adjustable tension device comprises a spring, having one end operably connected with a support, and the other end operably engaging the back at selected locations spaced apart from the tilt axis, such that rearward tilting of the chair back deflects the spring, and thereby generates a torque or back tension which resists further tilting. A shifter moves the other end of the spring between the selected back locations to vary the lever arm at which the spring acts, and thereby adjusts back tension. The shared-load arrangements comprises second and third springs, which are positioned on opposite sides of the first spring, and are operably connected between the support and the back. The second and third springs are pretensed to generate an initial torque which biases the back into a normally, fully upright position. The three controller springs combine to share the load applied to the back, with the second and third springs providing an initial, minimum back tension, and the first spring providing an additional, variable back tension.