Magnetic tape head indexing mechanism with single armature spring

Claim 2

A magnetic head indexing mechanism for use in a cartridgetype tape player adapted to receive and play tape cartridges having a multi-track tape therein and including a cam having a plurality of different cam surfaces, each one of which is associated with a different track on the tape and a cam follower in engagement with the cam for positioning the magnetic tape head, comprising a device for rotating the cam to position a different cam surface in contact with a cam follower with the playing of one of the different tracks on the tape, thereby automatically positioning the magnetic tape head to play a different track of the multi-track tape, said device including a solenoid unit having an armature movable between an extended position and a retracted position, only one spring element mounted on said armature, ratchet wheel coupled to the cam for rotation together with said cam, and first and second pawl members pivotally mounted on said armature in spaced relation with respect to each other with said ratchet wheel accommodated in the space between said first and second pawl members, said first and second pawl members being biased about the common pivot on the armature by said spring element in opposite directions towards each other, said first pawl member having a finger integrally formed therewith for sliding engagement with said ratchet wheel, thereby to prevent counter-rotation of said ratchet wheel, said second pawl member having a nail portion and an actuating portion both integrally formed therewith, and said first and second pawl members being in cooperative relation with respect to each other for rotating the ratchet wheel in one predetermined direction upon reciprocal movement of the armature.

Claim 3

A magnetic head indexing mechanism for use in a cartridge-type tape player adapted to receive and play tape cartridges having a multi-track tape therein and including a cam having a plurality of different cam surfaces, each one of which is associated with a different track on the tape and a cam follower in engagement with the cam for positioning the magnetic tape head, comprising a device for rotating the cam to position a different cam surface in contact with a cam follower with the playing of one of the different tracks on the tape, thereby automatically positioning the magnetic tape head to play a different track of the multi-track tape, said device including a solenoid unit having an armature movable between an extended position and a retracted position, only one spring element mounted on said armature, ratchet wheel coupled to the cam for rotation together with said cam, and first and second pawl members pivotally mounted on said armature in spaced relation with respect to each other with said ratchet wheel accommodated in the space between said first and second pawl members, said first and second pawl members being biased about the common pivot on the armature by said spring element in opposite directions towards each other, said first pawl member having a finger integrally formed therewith for sliding engagement with said ratchet wheel, thereby to prevent counter-rotation of said ratchet wheel, said second pawl member having a nail portion and an actuating portion both integrally formed therewith, and said first and second pawl members being in cooperative relation with respect to each other for rotating the ratchet wheel in one predetermined direction upon reciprocal movement of the armature.

Claim 4

A magnetic head indexing mechanism for use in a cartridge-type tape player adapted to receive and play tape cartridges having a multi-track tape therein and including a cam having a plurality of different cam surfaces, each one of which is associated with a different track on the tape and a cam follower in engagement with the cam for positioning the magnetic tape head, comprising a device for rotating the cam to position a different cam surface in contact with a cam follower with the playing of one of the different tracks on the tape, thereby automatically positioning the magnetic tape head to play a different track of the multi-track tape, said device including a solenoid unit having an armature movable between an extended position and a retracted position, only one spring element mounted on said armature, ratchet wheel coupled to the cam for rotation together with said cam, and first and second pawl members pivotally mounted on said armature in spaced relation with respect to each other with said ratchet wheel accommodated in the space between said first and second pawl members, said first and second pawl members being biased about the common pivot on the armature by said spring element in opposite directions towards each other, said first pawl member having a finger integrally formed therewith for sliding engagement with said ratchet wheel, thereby to prevent counter-rotation of said ratchet wheel, said second pawl member having a nail portion and an actuating portion both integrally formed therewith, and said first and second pawl members being in cooperative relation with respect to each other for rotating the ratchet wheel in one predetermined direction upon reciprocal movement of the armature.

Claim 5

An magnetic head indexing mechanism as claimed in claim 1, wherein said spring element comprises a compression spring having one end connected to a fixed portion and the other end in contact with said first and second pawl members for biasing the latter in the opposite direction toward each other about the common pivot.