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. 30, 1982
Filed:
Nov. 25, 1980
Applicant:
Inventors:
Assignee:
The Radiochemical Centre Limited, Buckinghamshire, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
250381 ; 250385 ;
Abstract
A smoke sensing detector for use with an indicating device comprises a chamber adapted to allow smoke to pass therethrough, an inner electrode carrying a radioactive source, a collector electrode having one or more holes and mounted on the inner electrode by insulating pillars, and an outer electrode. The collector and outer electrodes define a first ionization region, and the collector and inner electrodes define a second or reference ionizaton region which is comparatively little affected by the passage of smoke. Mounting the collector electrode on the inner electrode reduces costs, is easy and ensures that, in the event of insulation failure, the device is fail safe.