Data Recording Instrument Company Limited

Data Recording Instruments Limited

Derek F Case

Peter C Ridgway

David J Sansom

A magnetic transducing assembly including an elongate magnetic flux carrying core member, a substrate with a flat multi-turn spiral on a surface thereof and slit opening at the center of the spiral. The core is so engaged in the slit that the plane of the spiral is aligned with the elongate direction of the core and so that the spiral forms a coil about the core member.

Magnetic recording transducers

A method of bonding laminations of a magnetic core is disclosed in which photo-resist material consisting of a co-polymer is applied as a film to a sheet of magnetic material to define lamination shapes to enable the laminations to be formed by etching. The film of photo-resist material on the laminations is then utilized to bond the laminations together in a stack. In order to permit the core to operate at temperatures higher than the softening temperature of the photo-resist material, the bonded stack is irradiated to cause changes to the bonding material such that the material does not soften at the operating temperature of the core.

Magnetic core formed from laminations

A process for producing magnetic elements is disclosed in which magnetic material having a low copper content is utilized and, prior to deposition of copper for acting as a non-magnetic spacer, a layer of isolating material such as nickel is deposited to isolate the copper from the magnetic material so that, after mechanical working of the magnetic material to form an element and the element is annealed to restore its initial magnetic properties, the isolating layer acts to prevent the magnetic properties of the magnetic material from being degraded by the copper layer.

Magnetic material

A process for the manufacture of pole structures for magnetic transducing heads is described in which the configuration of the non-magnetic gaps is formed by abrading the ferrite pole structure through a mask to erode recesses in the gap area which have inclined walls. The final dimension of the gap defining face of one or the magnetic elements is determined by removing material from the masked face of the structure until the dimension between the recesses has the desired value.

Manufacture of magnetic transducing heads

A construction of a multi-track read and write head assembly is disclosed in which conductive shielding elements are interconnected with low resistance conductive paths by means of electrically conductive layers plated onto the shielding elements.

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Sunbury, United Kingdom

Derek F Case