Sound reproducing device incorporating a device for selecting a desired record groove

Claim 1

An improved sound reproducing device for selectively reproducing sounds recorded in a record disc being rotatably supported on a chassis and having an electric motor for driving said record disc when energized, a power source for energizing said motor, a tone arm swingably disposed on said chassis and resiliently urged toward the starting point of sound reproduction and away from the face of the record disc, a speaker, a sound transmitting member which is normally in contact with a side of said tone arm opposite to said record disc for transmitting reproduced sonic vibration to said speaker, a pickup forming a part of the tone arm and disposed between said transmitting member and said record disc, a stylus force spring for causing relative movement between said record disc and tone arm so as to produce a desired stylus force therebetween, a return arm disposed between said transmitting member and said record disc such that it is pushed by said tone arm upon the arrival of said tone arm at the end point of said sound reproduction path to ride on an upright cam disposed at the central portion of said record disc so as to enlarge the distance between said transmitting member and said record disc against the stylus force to thereby permit said tone arm to return to the starting point of said sound reproduction, wherein the improvement comprises: an electromagnetic actuator having a movable blade which sustains said sound transmitting member or record disc against the stylus force of said stylus force spring and releasing said sound transmitting member or record disc when energized; a switching transistor connected to said motor and said power source to form a first closed circuit when said transistor is turned on; a self-holding switch connected between said transistor and said power source so as to turn on said transistor when said self-holding switch is closed, said self-holding switch being designed such that it is opened when said tone arm is at the starting point of said sound reproduction path but it is closed while said tone arm is moving toward the end portion of said sound reproduction path; a manually operated start switch connected in parallel with said self-holding switch; an inhibitor switch adapted to be closed and opened when the distance between said record disc and said sound transmitting member is beyond and below a predetermined value, respectively; a rotary switch including a movable contact and a fixed contact; said movable contact being adapted to rotate with the rotation of said record disc so as to successively make contact with said fixed contact, said fixed contact being disposed such that said fixed contact is disposed at a position with a predetermined positional relationship with a position at which a pick-up of said tone arm descends so as to engage a selected recorded groove at a point slightly before the starting point of said sound reproduction path, said fixed contact further being correspondingly connected to said start switch so that said power source, said inhibitor switch, said electromagnetic actuator, said rotary switch and said start switch may form a second closed circuit through the selected start switch and the selected fixed contact corresponding to said start switch.