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. 12, 1996
Filed:
Jan. 03, 1995
C David Lunden, Federal Way, WA (US);
Other;
Abstract
A method and apparatus for sensing the temperature of a susceptor in a bond line in an inductive welding process utilizing a conductive susceptor at the interface between the two plastic parts, and a magnetic coil that generates an alternating magnetic field and projects the field through the parts and around the susceptor. As the susceptor gets hot, its electrical resistance changes as a function of the thermal coefficient of resistance of the susceptor material, and that change of resistance is reflected back as a change in the drive coil impedance. An electrical circuit senses the varying resistance and that change in resistance is translated into a change of temperature on a temperature display, and may be used to adjust the power to the work coil or the speed of travel of the work coil along the bond line. The circuit includes a high power bridge with a sensitive null arm to sense changes in the susceptor impedance due to temperature changes.