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. 29, 1993
Filed:
Apr. 06, 1992
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A magnetic head comprising magnetic core halves which are sealed with a sealing glass which consists essentially of 10 to 25% by weight of SiO.sub.2, 55 to 80% by weight of PbO, 1 to 15% by weight of CdO, 0 to 10% by weight of B.sub.2 O.sub.3, 0 to 5% by weight of ZnO, 0 to 5% by weight of Al.sub.2 O.sub.3, 0 to 5% by weight of Na.sub.2 O, and 0 to 10% by weight of K.sub.2 O, provided that a total content of Na.sub.2 O and K.sub.2 O does not exceed 10% by weight, has a coefficient of thermal expansion of from 90.times.10.sup.-7 /.degree. C. to 110.times.10.sup.-7 /.degree. C. in a temperature range between 30.degree. C. and 300.degree. C., a working temperature of 600.degree. C. or lower and water resistance of the second class or higher, which glass is not deeply colored and is not devitrified during the assembly of the magnetic head.