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:
Jan. 15, 1980
Filed:
Aug. 28, 1978
James G Allemann, South Gate, CA (US);
Norris Industries, Inc., South Gate, CA (US);
Abstract
To lock the head of a latchbolt in extended, or locked position therein to prevent opening of a door in case of fire the latch bolt head is provided with a spring driven locking pin reciprocatably mounted in a transverse direction. In the extended locked position of the latch bolt head the locking pin is in alignment with but withdrawn clear of a hole in the latch bolt case. At the inside end of the locking pin is a groove and a fusible pin normally engages the groove holding the locking pin in withdrawn position. This permits normal latch bolt action. When the fusible pin melts because of heat from a fire the locking pin is released and driven by spring action into the hole in the latch bolt case to physically bar withdrawal of the latch bolt, and consequent opening of the door.