Stereo phonograph pick-up cartridge
AssigneeSonic Research Inc.
InventorPeter E. Pritchard
Life of this patent
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Abstract
A magnetic stereo phonograph pick-up cartidge, including a removable stylus assembly of low mass which includes means for precisely aligning the armature with respect to the pole pieces. A boss on the stylus assembly and a mating aperture on the cartridge body assure alignment in the first instance, and a symmetrical, rubber, armature-pivot block is so positioned that perfect alignment between armature and pole pieces, and a proper tracking angle, are achieved only when the stylus is on a recording. The stylus assembly further includes a permanent magnet for energizing the armature, mounted so as to minimize interaction with the pole pieces and eliminate any distortion of the armature, and so provide a more linear, distortion-free response.
Claims8
An electromagnetic pick-up cartridge for phonograph records comprising:
- a housing containing sensing means and having a noncircular aperture in the forward wall thereof;
- a stylus assembly including a rearwardly-extending boss adapted for insertion into said aperture in a slight interference fit, whereby said assembly may be secured to said housing;
- a stylus cantilever mounted in said stylus assembly on a resilient pivot block, said pivot block comprising an outer, cylindrical portion and an inner, inwardly-tapering portion terminating in a square, stylus cantilever-engaging aperture, said engagement defining the pivot point of said cantilever;
- a magnetically permeable armature forming part of said cantilever;
- and
- a magnet mounted in said stylus assembly to magnetically energize said armature.
An electromagnetic pick-up cartridge for phonograph records comprising:
- a housing containing an electromagnetic circuit including a pair of coils and a pair of pole pieces extending exterior of said coils into a first aperture in the forward wall of said housing;
- a second, non-circular aperture in the forward wall of said housing;
- a stylus assembly detachably securable to said housing and including a rearwardly extending boss adapted for insertion into said second aperture in a slight interference fit;
- a pivotally mounted stylus cantilever on said stylus assembly and including a rearwardly-extending magnetically permeable armature, said armature extending into said first aperture when said stylus assembly is secured to said housing;
- and
- a permanent magnet mounted in said stylus assembly and positioned to magnetically energize said armature.
Dependencies are inferred from the claim text.