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. 07, 1978
Filed:
Dec. 30, 1975
Kwok-Wah Pun, Kowloon, HK;
Other;
Abstract
A detecting device for detecting heat due to the presence of fire for example. The detecting device includes an open-ended chamber closed by a resilient diaphragm. The diaphragm engages the open end to permit respectively the passage of air via an annular passageway formed between an outer peripheral portion of the diaphragm and a circumferential rim of the open end which it engages for closing the chamber, upon pressure build-up in the chamber due to the external temperature variation. This pressure build-up causes corresponding expansion of the diaphragm to thereby actuate an electrical circuit provided with means for emitting an audible sound. Means are also provided in the detector to make it operative in response to the presence of moving objects.