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. 14, 1995
Filed:
Jan. 06, 1994
Takijiro Shimamoto, Nagasaki, JP;
Yoji Morita, Nagasaki, JP;
Ichiro Shimasaki, Nagasaki, JP;
Ichiro Matsuura, Nagasaki, JP;
Tsukasa Maenosono, Kawasaki, JP;
Mitsubishi Jukogyo Kabushiki Kaishi, Tokyo, JP;
Dai-ichi High Frequency Co., Ltd., Tokyo, JP;
Abstract
A high frequency bolt heater is provided which can heat up the inside of a narrow hole much faster than a conventional bolt heater employing a resistance wire. The high frequency bolt heater includes an induction heating coil made of a copper tube bent in a hairpin fashion and whose shape is made approximately circular in section by pinching a magnet between opposed portions thereof. The heater can be inserted into a hole bored in the axial direction of a metallic bolt. A length of the coil is made approximately equal with that of the bored hole, and the magnet is omitted from a region of the heater which corresponds to a screw portion of the bolt for mounting a nut. An adjustable stopper made of a heat resistant electrical insulator is provided for setting a necessary length of the induction heating coil to be inserted into the hole, and a heat resistant insulator is provided on the surface of the induction heating coil.