Apparatus for shifting magnetic head in multitrack tape player

Claim 1

An apparatus for shifting magnetic head in multitrack tape player including a rotary capstan for driving a magnetic tape and at least one magnetic head adapted to transduce the tape, said apparatus comprising: a displaceable support member coupled to the magnetic head for positioning it with respect to a plurality of discrete and separate record tracks on the magnetic tape; cam means coactable with the support member for controlling displacement of the magnetic head to play the record tracks, said cam means having a plurality Of successive cam regions spaced apart in correspondence with the record tracks, said cam regions being constructed to displace the support member to corresponding positions when in individual coaction therewith and thereby position the magnetic head for play with associated record tracks; driving means for rotating the cam means in single steps to position the magnetic head to successive record track positions, said driving means including a rotary member provided coaxially with the cam means, a swing lever swingably provided, a frictional idler wheel rotatably mounted on said swing lever and abutting against said capstan to allow said idler wheel to be rotated with rotation of said swing lever, and a transmission member for transmitting rotation of said frictional idler wheel to said rotary member, control means for controlling swingable movement of the swing lever, said control means including a lever member displaceably provided, a link member connected to a portion offset from the center of the frictional idler wheel and one end portion of said lever member, a tension spring urging said lever member in one direction for providing swingable motion to the swing lever via said lever member, said link member, and the frictional idler wheel in a manner that the frictional idler wheel abuts against the capstan, a solenoid means retaining said lever member against the elasticity of said tension spring for maintaining the swing lever at a position where the frictional idler wheel is not rotatably driven by the capstan, and a control circuit generating the record-track-switching signal for energizing said solenoid means in pulse fashion, said solenoid means being energized by said control circuit to move said actuator to a position where said actuator is released from said lever member and in response thereto the swing lever being swung by the bias of said tension spring to a position where the frictional wheel abuts against the capstan and is then rotated, said lever member being reciprocated by said link member in response to rotation of the frictional idler wheel, said link member being retained by said solenoid means when the wheel rotates round its axis while said swing lever being returned to a position where the wheel does not receive rotational force of the capstan, and said frictional idler wheel rotating round its axis whenever said solenoid means is energized by said control circuit.

Claim 2

An apparatus for shifting magnetic head in multitrack tape player including a rotary capstan for driving a magnetic tape and at least one magnetic head adapted to transduce the tape, said apparatus comprising: a displaceable support member coupled to the magnetic head for positioning it with respect to a plurality of discrete and separate record tracks on the magnetic tape; cam means coactable with the support member for controlling displacement of the magnetic head to play the record tracks, said cam means having a plurality Of successive cam regions spaced apart in correspondence with the record tracks, said cam regions being constructed to displace the support member to corresponding positions when in individual coaction therewith and thereby position the magnetic head for play with associated record tracks; driving means for rotating the cam means in single steps to position the magnetic head to successive record track positions, said driving means including a rotary member provided coaxially with the cam means, a swing lever swingably provided, a frictional idler wheel rotatably mounted on said swing lever and abutting against said capstan to allow said idler wheel to be rotated with rotation of said swing lever, and a transmission member for transmitting rotation of said frictional idler wheel to said rotary member, control means for controlling swingable movement of the swing lever, said control means including a lever member displaceably provided, a link member connected to a portion offset from the center of the frictional idler wheel and one end portion of said lever member, a tension spring urging said lever member in one direction for providing swingable motion to the swing lever via said lever member, said link member, and the frictional idler wheel in a manner that the frictional idler wheel abuts against the capstan, a solenoid means retaining said lever member against the elasticity of said tension spring for maintaining the swing lever at a position where the frictional idler wheel is not rotatably driven by the capstan, and a control circuit generating the record-track-switching signal for energizing said solenoid means in pulse fashion, said solenoid means being energized by said control circuit to move said actuator to a position where said actuator is released from said lever member and in response thereto the swing lever being swung by the bias of said tension spring to a position where the frictional wheel abuts against the capstan and is then rotated, said lever member being reciprocated by said link member in response to rotation of the frictional idler wheel, said link member being retained by said solenoid means when the wheel rotates round its axis while said swing lever being returned to a position where the wheel does not receive rotational force of the capstan, and said frictional idler wheel rotating round its axis whenever said solenoid means is energized by said control circuit.