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:
Dec. 07, 1993
Filed:
Jul. 24, 1992
Tokio Uetsuhara, Tokyo, JP;
Yuichi Ando, Tokyo, JP;
Kenji Iio, Tokyo, JP;
Kenichiro Kinoshita, Tokyo, JP;
Abstract
A plunger type electromagnet is provided with an attractive plate connected to the plunger, with an improved configuration of plunger and stationary element, or with a flanged tubular member of magnetic material affixed to the axial end of a coiling bobbin, in order to increase the rate of change in the permeance of the magnetic circuit at the time of attractive operation and to enhance the sensitivity of the electromagnet. Furthermore, the surface area of the abutment faces of the stationary and movable elements is calibrated so as to control the attractive and retaining force thereof. In some embodiments, a permanent magnet is provided which is shaped in the form of an annulus and is magnetized in the direction of thickness of the annulus, so as to facilitate magnetization of the permanent magnet, to reduce the number of component parts, and to provide an electromagnet which is compact in size, light in weight, and suitable for mass production.