Tape recorder mechanism responsive to tape stoppage

Claim 2

In a tape recorder comprising: a chassis; a command member movably connected to the chassis and biased toward a switched-off position; means for moving the command member to an operative position; biased latching means for latching said command member in the operative position; a flywheel mounted to the chassis for rotation; means for rotatably driving the flywheel and for causing transport of tape in said tape recorder; means for detecting stoppage of tape transport while said command member is in said operative position, and means responsive to said detecting means, for switching off said driving means, comprising a frame plate movably mounted to the chassis for a given motion from an initial position upon detection of tape stoppage, a force transmitting member arranged to operatively engage said latching means so as to unlatch said command member, and means for applying operative force to said force transmitting member in response to said given motion of the frame plate, the improvement comprising: a drive wheel rotatably journalled on the frame plate, and means responsive to said given motion for engaging said drive wheel for frictionally driven rotation responsive to the flywheel rotation, and wherein said force transmitting member is drivably coupled to said drive wheel for applying said operative force to said force transmitting member.

Claim 3

A tape recorder as claimed in claim 1 wherein said frame plate, drive wheel and force transmitting member are so arranged that application of operative force to the force transmitting member increases the frictional driving force of the drive wheel.

Claim 4

A tape recorder as claimed in claim 2 wherein said means for applying force further comprises a winding drum and means coupling said winding drum to said driving wheel for rotation responsive to driving wheel rotation, and said force transmitting member consists of a flexible tension member having an end attached to the winding drum.

Claim 5

A tape recorder as claimed in claim 3 wherein said means for applying force comprises a spindle attached to the frame plate, the winding drum and the drive wheel being both journalled on said spindle.

Claim 6

A tape recorder as claimed in claim 4 wherein said means for applying force further comprises a reduction gear train operatively coupled between said driving wheel and said winding drum such that said drum rotates at a lower speed than the wheel.

Claim 7

A tape recorder as claimed in claim 1 wherein said frame plate has a slot having a length greater than a stroke of the command member as the command member moves from the operative position to the switched-off position, said slot extending longitudinally generally in the direction of said stroke, said command member includes a stop pin protruding therefrom and arranged to project through said slot, and said switching off means comprises a spring for biasing the frame plate in a direction opposite to said given motion, said slot having a width, at a location where the stop pin is situated when the command member is in the operative position, sufficiently great to allow the frame plate to undergo said given movement; a width at a location where the stop pin is situated when the command member is in the switched-off position, only slightly wider than the stop pin, so arranged that said frame member is held in said initial position; and between said locations said slot width changing gradually such that, upon movement of the command member from the operative position to the switched-off position in response to detection of tape stoppage, the frame plate is returned to the initial position by engagement to the stop pin.

Claim 8

A tape recorder as claimed in claim 1, wherein said detecting means comprises a differential rotary motion mechanism having an output drive assembly which rotates in a first direction during normal tape transport in response to said command member being in the operative position, and in an opposite second direction in response to tape stoppage; and said switching-off means comprises a sensor element pivotally connected to the frame plate and having an end remote from the frame plate, and means for resiliently engaging the sensor and with the output drive assembly at least while said command member is in the operative position.

Claim 9

A tape recorder as claimed in claim 7 wherein said output drive assembly comprises: a disk having a first cam ring having a number of cam teeth with sawtooth profiles and an interspace between adjacent cam teeth, so arranged that during normal tape transport the gradual sloping sawtooth surface leads the steep edge; a second cam ring mounted concentrically with said first cam ring and having a number of cam teeth with generally symmetrical sloping profiles, and an interspace between adjacent cam teeth; and means for coupling said second cam ring to said first cam ring for common rotation with a given difference in relative angular position of the cam rings with respect to each other for opposite directions of rotation, such that when rotating in said first direction corresponding to normal transport, sloping profiles of the second cam ring teeth are aligned with respective interspaces of the first cam ring so that said sensor end engages sloping surfaces only; and such that when rotating in the opposite direction, frictional drag of the sensor end bearing on the assembly retards rotation of one of said cam rings by said given difference in position thereby aligning interspaces of the cam rings, so that said sensor end engages said interspace and is moved such that the frame plate undergoes said given motion.

Claim 10

A tape recorder as claimed in claim 8, wherein said sloping profiles of the second cam have a slope equal to that of the gradual sloping sawtooth surfaces, when rotating in said first direction each gradual sloping sawtooth surface being coincident with a respective second cam ring sloping profile.

Claim 11

A tape recorder as claimed in claim 8, wherein said frame plate is connected to the chassis for pivotal movement about an axis parallel to rotational axes of the flywheel and the differential rotary mechanism, and the sensor arm is pivotal with respect to the frame plate about an axis transverse to said axes; and the command member further comprises a sensor lifting cam which is arranged so as to lift the sensor end off the output drive assembly when the command member is in the switched-off position.

Claim 12

A mechanism for moving an element in response to stoppage of a shaft rotation, comprising: a chassis; a shaft journalled to said chassis for rotation; a differential rotary motion mechanism mounted on said shaft, having an output drive assembly which rotates in a first direction during rotation of said shaft in a given direction, and in an opposite second direction in response to stoppage of said shaft; a member mounted to said chassis so as to allow motion with respect to said chassis in first and second orthogonal directions, and having an end; means for biasing said member in said first orthogonal direction so as to resiliently engage said output drive assembly; and means for moving an element responsive to movement of said member in said second orthogonal direction; wherein said output drive assembly comprises: a disk having a first cam ring having a number of cam teeth with sawtooth profiles and an interspace between adjacent cam teeth, so arranged that during rotation of said shaft in said given direction the gradual sloping sawtooth surface leads the steep edge; a second cam ring mounted concentrically with said first cam ring and having a number of cam teeth with generally symmetrical sloping profiles, and an interspace between adjacent cam teeth; and means for coupling said second cam ring to said first cam ring for common rotation with a given difference in relative angular position of the cam rings with respect to each other for opposite directions of rotation, such that when rotating in said first direction corresponding to said given shaft direction, sloping profiles of the second cam ring teeth are aligned with respective interspaces of the first cam ring so that said member end engages sloping surfaces only; and such that when rotating in the opposite second direction, frictional drag of the member end bearing on the assembly retards rotation of one of said cam rings by said given difference in position thereby aligning interspaces of the cam rings, so that said member end engages said interspace and said member is moved in said second orthogonal direction.

Claim 13

A mechanism for moving an element in response to stoppage of a shaft rotation, comprising: a chassis; a shaft journalled to said chassis for rotation; a differential rotary motion mechanism mounted on said shaft, having an output drive assembly which rotates in a first direction during rotation of said shaft in a given direction, and in an opposite second direction in response to stoppage of said shaft; a member mounted to said chassis so as to allow motion with respect to said chassis in first and second orthogonal directions, and having an end; means for biasing said member in said first orthogonal direction so as to resiliently engage said output drive assembly; and means for moving an element responsive to movement of said member in said second orthogonal direction; wherein said output drive assembly comprises: a disk having a first cam ring having a number of cam teeth with sawtooth profiles and an interspace between adjacent cam teeth, so arranged that during rotation of said shaft in said given direction the gradual sloping sawtooth surface leads the steep edge; a second cam ring mounted concentrically with said first cam ring and having a number of cam teeth with generally symmetrical sloping profiles, and an interspace between adjacent cam teeth; and means for coupling said second cam ring to said first cam ring for common rotation with a given difference in relative angular position of the cam rings with respect to each other for opposite directions of rotation, such that when rotating in said first direction corresponding to said given shaft direction, sloping profiles of the second cam ring teeth are aligned with respective interspaces of the first cam ring so that said member end engages sloping surfaces only; and such that when rotating in the opposite second direction, frictional drag of the member end bearing on the assembly retards rotation of one of said cam rings by said given difference in position thereby aligning interspaces of the cam rings, so that said member end engages said interspace and said member is moved in said second orthogonal direction.

Claim 14

A mechanism as claimed in claim 11 wherein said sloping profiles of the second cam have a slope equal to that of the gradual sloping sawtooth surfaces, when rotating in said first direction each gradual sloping sawtooth surface being coincident with a respective second cam ring sloping profile.

Claim 15

A mechanism as claimed in claim 11, comprising a frame plate connected to the chassis for pivotal movement about an axis parallel to rotational axes of the shaft and differential rotary mechanism, said member being pivotally mounted to said frame plate about an axis transverse to said axes; wherein said mechanism further comprises means for selectively moving said member in opposition to said biasing about said transverse axis so as to move said member out of engagement with the output drive assembly, whereby said mechanism is disabled and insensitive to rotation of the shaft in a reverse direction.