Precision lapping system
AssigneeMagnetic Peripherals Inc.
InventorsDouglas J. Hennenfent, Allan L. Holmstrand, Alan G. Kracke
Life of this patent
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Abstract
Apparatus for precisely machining the surface of a workpiece comprises a rotating plate with a flat, horizontal abrasive-laden surface against which the workpiece surface is forced by gravity. The workpiece is carried on the free end of an arm pivotably supported remote from the end of the arm carrying the workpiece. Loading of the workpiece work surface can be varied by shifting weights along the length of the arm or transverse to the length of the arm. The workpiece itself can comprise a bar on which several magnetic transducing heads have been deposited. Machining the workpiece surface to a preferred position accurately defines a dimension of choice, such as the throat height of these transducers.
Claims19
Apparatus for machining a workpiece surface, said surface having initial lateral stability, comprising:
- a. a substantially rigid frame;
- b. a lapping body having a substantially flat lapping surface carrying thereon abrasive particles within a predetermined area, and mounted on the frame for rotation about a vertical axis with the lapping surface substantially horizontal;
- c. a motor mounted on the frame and operatively connected to the body to provide torque for rotating the body;
- d. a carrier arm support attached to the frame;
- e. a rigid carrier arm assembly attached to the carrier arm support by a carrier arm pivot having a horizontal axis of rotation extending generally toward the predetermined area of the lapping body and lying within a predetermined distance of the plane of the lapping surface, said carrier arm assembly having a generally vertically extending segment journaled at the pivot, a segment extending generally horizontally toward the predetermined area of the lapping surface and along the carrier arm pivot's horizontal axis of rotation, and fixed to the upper end of the vertically extending segment, and a workpiece carrier attached to the horizontally extending segment at a point above and extending downwardly toward the lapping surface;
- and
- f. means cooperating with the carrier arm support and the carrier arm pivot for allowing the workpiece carrier vertical movement above the lapping surface, wherein the workpiece carrier element includes a workpiece attachment means for fixing the workpiece with the surface to be machined facing downwardly toward and resting with gravity pressure on the lapping surface and within the circles traced by the inner and outer peripheries of the abrasive-carrying area.
Dependencies are inferred from the claim text.