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:
May. 22, 1979
Filed:
Nov. 30, 1977
Applicant:
Inventor:
Hermann Budmiger, Seewen, CH;
Assignee:
Revue Thommen AG, Waldenburg, CH;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
A61F / ;
U.S. Cl.
CPC ...
2-8 ; 350150 ;
Abstract
A welder's helmet has a window with an upper section of invariable light-attenuation characteristics and a dimmable lower section comprising an ultraviolet filter, an infrared filter, and an electro-optical shutter such as a liquid crystal sandwiched between a polarizer and an analyzer. A control circuit including a UV-sensitive photocell, upon sensing a welding arc or flame, operates the shutter to reduce the amount of light transmitted through the lower section of the window.