2-channel - 4-channel changeover device in a cartridge-type tape recorder

Claim 1

A 2-channel - 4-channel changeover device in a tape recorder having a loading part for insertion and loading thereinto a 2channel cartridge accommodating therewithin a tape having a total of 8 tracks in groups each of four program tracks or, interchangeably, a 4-channel cartridge accommodating therewithin a tape having a total of 8 tracks in groups each of two program tracks, a magnetic head device having four head elements for abutting against four tracks on a tape, a mechanism for changing the height position of said magnetic head device in four steps in correspondence with first through fourth program tracks of said 2-channel cartridge, and a plunger for actuating said heightchanging mechanism, said changeover device comprising: a normally-closed first switch connected to said plunger; a relay switch connected to said first switch; a relay-driving circuit for closing said relay switch during a short time required for one cycle of operation of said plunger; a second switch connected to said relay-driving circuit to carry out changeover switching; switching means for opening and closing said relay-driving circuit capable of closing said relay-driving circuit through said second switch when said magnetic head is in the height position corresponding to the third and fourth program track in accordance with the operation of said height changing mechanism; a third switch for connecting and disconnecting the power supply to the actuating device and to the relay-driving circuit; a rectifying circuit for rectifying AC power supplied through said third switch into direct-current power; a smoothing capacitor for smoothing the output direct-current voltage of said rectifying circuit and supplying the voltage thus smoothed to said plunger; and a switch operation changeover mechanism having a detecting part which is actuated by a 2-channel cartridge inserted into said loaded position, and which, when a 4-channel cartridge is inserted into the loaded position, enters into a slot formed in a specific position of said 4-channel cartridge; said switch operation changeover mechanism operating, (1) when the 2-channel cartridge is inserted into a predetermined loaded position within the tape recorder, firstly to open said first switch, secondly to changeover said second switch in a manner to break the connection of said relay-driving circuit and said switching means for opening and closing the relay-driving circuit, and thirdly to close said third switch, (2) when the 2-channel cartridge is extracted from the tape recorder, firstly to open said third switch, secondly to changeover said second switch in a manner to connect the relay-driving circuit and the switching means for opening and closing the relay-driving circuit, and thirdly to close the first switch whereby the first switch is closed after a charge in said capacitor has been discharged to a degree which will not cause said plunger to operate after said third switch opens, and (3) when the 4-channel cartridge is inserted into the predetermined loaded position, to close the third switch, and not to open the first switch and not to changeover the second switch.