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US 4,073,495 AGranted
Advancement of stuck phonograph needles
OwnerPeter Royceinventor
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OwnerPeter Royceinventor
Estimating the term…
To advance a "stuck" phonograph needle, a solenoid is mounted in or on the tone arm so that movement of the plunger causes an impact on the arm tending to move the arm upwardly and forwardly (i.e. toward the center of the record). The turntable underside has a magnetic recording track which is tracked by a record and playback head. The record head records vibrations from the record grooves, via the stylus onto the magnetic track, one track at a time. On the next revolution of the turntable the playback head and this information is reversed in phase, and compared with the information currently received from the stylus. If the needle is "stuck", the recorded and current information should null out and this null is detected, causing the solenoid to be energized to create the impact to advance the stylus one groove of the record.
A device for advancing a "stuck" stylus having a current output for use in a record player having a turntable on which a record having multiple grooves is rotated and a tone arm having a stylus to engage said record, comprising impact means mounted on or in said tone arm of a phonograph operable to deliver an impact to said tone arm to drive said stylus upwardly and inwardly relative to said record to advance said stylus at least one record groove and actuating means for actuating said impact means, said actuating means comprising recording means for temporarily making a temporary record of the output of said stylus for one rotation of said turntable, comparison means for detecting when the current output of said stylus is substantially identical with said temporary record and thereby to detect when said stylus is stuck in a groove, and means responsive to said comparison means for activating said impact means.
A method for advancing a "stuck" stylus having a current output for use in a record player having a turntable on which a record having multiple grooves is rotated and a tone arm having a stylus to engage a groove of said record said method comprising the step of electrically comparing the current output of said stylus with the current output of said stylus one revolution of said turntable previous to determine if said outputs are substantially identical and upon said detection of substantial identity the step of generating an electrical signal and the step of actuating by said signal means to deliver an impact to said tone arm in a direction to advance said stylus to the next groove of said record.
Dependencies are inferred from the claim text.