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:
Jul. 19, 1977
Filed:
Dec. 29, 1975
John Hershel English, North Plainfield, NJ (US);
James Edward Griffiths, Murray Hill, NJ (US);
Paul Zuk, Allentown, PA (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
Electrical equipment, such as telephone station apparatus, exposed to occasional, destructively high, voltage surges (e.g., lightning strikes) is protected by a device, placed in parallel with the equipment, including two electrodes defining a fixed narrow spark gap which breaks down (arcs over) to short the voltage surge to ground. The predominant failure mode of such devices is shorting across the narrow gap, due to electrode damage produced during the protective arcing mode. In the disclosed devices, the electrodes are contoured to define a narrow region, determining the protective breakdown voltage, and a wider region, sustaining the major part of the electrode damage. Shortly after the initiation of the protective discharge in the narrow gap region, the discharge moves into the wider gap region. Since the major portion of electrode damage is sustained by the wider gap region of the electrodes, the incidence of shorting failure is suppressed. An exemplary electrode profile includes a flat central region and a surrounding tapered region.