Hitachi, Ltd.

Toshio Ohji

Juichi Morikawa

Hideo Zama

Hitoshi Odashima

Hiromichi Hiramatsu

Kuniaki Hirayama

Shinji Okada

Yuji Kanda

A composite coil member for use in a rotary transformer is disclosed which is easily assembled and easily fitted in a transformer core of the rotary transformer. A plurality of coaxial conductive coils 4 are formed photolithographically on a plurality of coaxial portions of a flexible insulating member prepared by photolithography and the respective coaxial portions of the flexible insulating member are supported at at least three points on each coaxial portion by radially extending connecting portions 8 of the flexible insulating member.

Rotary transformer

A rotary magnetic head apparatus comprises a transformer core, including a rotor core and a stator core, a rotary drum, a stationary drum, and magnetic heads provided in the outer peripheral portion of the rotary drum. Signal transmission coils are disposed in a plurality of grooves formed concentrically in a surface of the core to transmit signals to and from the magnetic heads. Windings of each of the coils are positioned and lined with a flexible insulating layer so as to keep their mutual positional relation unchanged. The insulating layer is removed from the coil at portions corresponding to starting and terminating ends of the winding thereof. The insulating layer is bonded to the bottoms of the grooves. Through holes are formed in the core at positions corresponding to the starting and terminating end portions of the windings of the coil. Conductive junction members extend in the through holes and are electrically connected to the starting and terminating end portions of the windings of the coils to transmit signals to and from the magnetic heads.

Coil assembly for rotary magnetic head apparatus

A rotary magnetic head device and a rotary transformer used therefor are disclosed. A pair of througholes, through which the starting extremity and the ending extremity of each of a plurality of coil conductors disposed on the rotor core and the stator core constituting the rotary transformer are led to the respective rear surfaces, are linked by a linking slit. Alternatively one throughhole, through which both the starting extremity and the ending extremity of each of the coil conductors are led, is divided into two throughholes by disposing therein a non-magnetic partitioning member having a thermal expansion coefficient close to that of the magnetic body within a region of 15%. In this way, the two throughholes behave magnetically as if the starting extremity and the ending extremity of each of coil conductors passed through one throughhole, so that magnetic field components produced at the starting portion and the ending portion cancel each other and that the coupling coefficient between the rotor core and the stator core is increased.

Rotary magnetic head device with rotary transformer having high coupling

A coil mounting method and apparatus is disclosed, for example, for mounting coils to the inner periphery of a cylindrical core in assembling a cylindrical rotary transformer of a VTR cylinder. A wire is wound round the outer periphery of a coil holding jig that is capable of opening and closing in a radial direction. After the coil is formed, the coil holding jig is inserted into a cylindrical article and opened radially to have the coil fitted in a coil groove formed in the inner periphery of the cylindrical article. The mounting of the coil to the inner periphery of a cylindrical article can be done in a short time through a reduced number of steps.

Method and apparatus for mounting coils inside a hollow cylindrical

A rotary magnetic head assembly comprises rotatable and stationary cylinders disposed in confronting relation to each other. A rotary transformer is arranged between the cylinders and includes confronting rotatable and stationary transformer cores fixedly mounted respectively to the rotatable and stationary cylinders. An annular supporting member is located at an outer peripheral surface of the stationary transformer core and includes support portions for supporting the stationary transformer core. Signal transmission junction elements are provided on the outer peripheral portion of the supporting member. The outer peripheral portion of the supporting member is provided with bores through which fixing members are inserted to fix the stationary transformer core to the stationary cylinder. The outer peripheral surface of the stationary transformer core is formed to have a non-circular shape so that the outer peripheral portion of the stationary transformer core can rest on the support portions of the supporting member.

Growing community of inventors

Mito, Japan

Toshio Ohji