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:
Feb. 16, 1988
Filed:
Dec. 19, 1986
Noboru Takada, Tsurugashima, JP;
Toko Kabushiki Kaisha, Tokyo, JP;
Abstract
The construction of cores in an electric-current-controlled type variable inductor used in radio receivers is disclosed. The inductors have three or four cores. In the case of the variable inductors of the type having three cores, the winding portion of a first core is formed with a hollow portion, a second core is inserted into the hollow portion in such a way that the winding portion of the second core can be maintained in parallel with the winding portion of the first core, the first core is inserted into a pot-shaped third core in such a way that the winding portion of the first core can be maintained perpendicular to the bottom of the third core and the magnetic path established by a control coil mounted on the first core and the magnetic path established by a tuning coil mounted on the second core are superimposed one upon another around the winding portion of the second core. According to the present invention, the second core through which is extended the magnetic path established by the tuning coil and a part or means for substantially covering the second core are made of a high-frequency material (or a material best adapted to operate at a high frequency) while the remaining parts through which is extended the magnetic path established by the control coil is made of a low-frequency material (or a material best adapted to operate at a low frequency). Furthermore, in the case of variable conductors each having four cores, a fourth core is made of a high-frequency material, confines the magnetic path established by the tuning coil and is so disposed as to cover the second core in the hollow portion.