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:
Jun. 22, 1993
Filed:
Mar. 02, 1992
Warren E Herwig, Oshkosh, WI (US);
Miller Electric Manufacturing Company, Appleton, WI (US);
Abstract
A weld current switch includes a channel-shaped core, a shunt, and a magnetic reed switch. The magnetic reed switch and shunt are placed across the core poles. An electrical conductor carrying high current passes through the core. Upon deenergization of the electrical current, a residual magnetism remains in the core. The residual magnetism is normally high enough to prevent the magnetic reed switch from opening. However, the shunt directs sufficient magnetic flux from the switch such that the switch senses a much lower level of magnetic flux than if the shunt were not present. As a result, the switch opens, even with the high residual flux in the core. The increased reliability of the switch upon decreasing current at electrical conductor deenergization enables the weld current switch to use a higher sensitivity switch than was formerly possible. The higher sensitivity switch reduces the level of magnetic flux at which the reed switch will close on increasing current upon energization of the electrical conductor.