International Business Machines Corporation

Neil L Robinson

Frank B Shelledy

Ralph D Silkensen

Edmond W Smathers

John A Barkley

Samuel D Cheatham

Paul D Losee

Ralph D Brower

A batch fabricated multi-element head is made from interlocking ferrite parts to form a low contoured surface for interfacing with a magnetic medium, such as a flexible disk. On another surface, a multi-turn conductive coil is formed by thin film process and cooperates with a flux path bar to define the magnetic flux field.

Multi-element head assembly

An AC magnetic erase head having improved AC erase characteristics, the magnetic head being formed of two half core elements of a magnetic material, preferably ferrite, defining an irregular edged or jagged-edged gap, and including a non-magnetic substance, preferably glass, within the gap. The magnetic head is preferably produced by thermally etching ferrite magnetic material forming the half core elements by means of relatively prolonged heat soak at an elevated temperature.

Magnetic head having a jagged-edged gap, and method for producing such

A method for batch fabricating magnetic heads with a desired cant angle in the transducing surface of the magnetic core. The cant angle reduces the 'Minor Bit' phenomenon. The two parts of the core which require the cant angle are mounted on a fixture so that a grind wheel is simultaneously in contact with both parts. Materials are simultaneously subtracted (i.e., grind away) from both parts to create mirror images at the surfaces which adjoin the grind wheel. The surfaces are then cleaned and glassed to provide a core bar with intimate fit. The core bar is diced into individual cores and is lapped to size. The individual cores are then fitted into a slider assembly to form the magnetic head.

Method of making magnetic head cores with cant angles

This magnetic head construction includes two or more elements defining a transducing gap which are positioned and held together within a shell by a wedge. The magnetic head assembly disclosed normally includes a shell structure, a pair of transducer elements defining a transducing gap, a wedge and a wedge follower. The wedge follower may be present as either a separate element or as a surface carried by one of the transducer elements. The assembly is normally formed by the process of disposing the transducer elements, and the wedge follower, if present, within the shell wall, and then rough positioning these elements within the shell, followed by the insertion of the wedge against the wedge following surface to bring the parts into final position in a locked relationship. Generally speaking, locking is achieved by selecting the wedge angle, .theta. as a function of the coefficients of friction of the mating surfaces according to given formulae. This head structure and process requires no additional adhesive, glass, or other material to lock the parts of the structure together.

Magnetic head housing with wedge locking means

A head is moved toward and rotated against an abrasive while its resistance is monitored by a four-lead bridge. Prior to final manufacture, the head includes a highly conductive segment which surrounds the active head element on three sides and is electrically connected to it at one point. The segment is ground away during manufacture. Two leads from the head are connected to two slip rings, and each slip ring has two pairs of brushes, each wire from the bridge going to a different brush pair. Head movement toward the abrasive is terminated when a predetermined head resistance is detected by the bridge.

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Boulder, CO, United States of America

Neil L Robinson