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:
Feb. 03, 1987
Filed:
May. 06, 1985
Lee T Lamond, North Wales, PA (US);
Richard D Staton, Collingswood, NJ (US);
Fichtel & Sachs Industries, Colmar, PA (US);
Abstract
A support column unit for an adjustable-height chair and the like comprises upper and lower telescoping tubular members, a piston-and-cylinder type pneumatic spring located coaxially within the tubular members and having its cylinder member secured to the lower tubular member, and a gravity dependent locking mechanism for locking the piston rod member of the pneumatic spring to the upper tubular member when the support column is upright and for releasing the piston rod member when the support column is inverted. The locking mechanism comprises a lock body retained within the upper tubular member and having a bore sized and positioned to permit sliding axial movement of the piston rod member therein. The lock body has one or more cavities, each one in communication with the bore and containing a locking member. The cavities and the locking members are sized and shaped such that when the support column is upright, each locking member falls to a position in which a portion thereof protrudes into the bore, and when the column is inverted, each locking member falls to a position in which it is fully retracted from the bore. The piston rod member has an annular retaining groove shaped to engage the portions of the locking members that protrude into the bore to achieve locking of the piston rod member to the lock body when the column is upright.