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:
Mar. 09, 1993
Filed:
Jun. 21, 1991
Applicant:
Inventors:
Robert Hack, Lahnau, DE;
Wilhelm Polhede, Bruchkobel, DE;
Assignee:
Arthur Pfeiffer Vakuumtechnik Wetzlar GmbH, Asslar, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F27D / ;
U.S. Cl.
CPC ...
373112 ; 373109 ; 373117 ; 373128 ; 136230 ; 174151 ; 338 26 ; 374 24 ;
Abstract
An electrically heated vacuum furnace is provided with special lead-through devices for transmitting current to the heating elements. In order to recognize gas discharges which can occur between a lead-through and a tank wall, the insulation of the lead-through is surrounded by an auxiliary electrode. A thermocouple can also be used instead of an auxiliary electrode. A signal derived from the auxiliary electrode can be used to shut off the furnace power to avoid damage thereto.