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:
Apr. 19, 1988
Filed:
Nov. 18, 1985
James C Muth, Milwaukee, WI (US);
Otto E Kersten, Jr, Milwaukee, WI (US);
Gregory A Kulpa, South Pasadena, CA (US);
Milcor Incorporated, Lima, OH (US);
Abstract
This disclosure relates to an access door assembly for a ceiling. The assembly includes a frame adapted to be attached to supports of the ceiling and mounted in a generally horizontal position, and a door which fits within and has one edge hingedly connected to the frame. The hinge enables the door to swing between a generally horizontal closed position within the frame and a lowered open position. A constant-force return spring urges the door to the closed position, and an automatically engageable lock is provided for holding the door in the closed position. The frame and the door have closely adjacent Z-shaped frame members and the door is made of heat-resistant material, to form a fire retardant construction.