Fixed torque spring clutch and a winder having the same

A winder for winding a wound member such as a tape, a string, or a wire, comprising:

• a first rotor for transmitting a driving force from a driving source, said first rotor having a shaft section, said shaft section having an outer circumferential surface;
• a coil spring engaging said shaft section, said coil spring including a clamping section engaging said shaft section and a non-clamping section arranged in spaced relation with said shaft section, said clamping section having a first engagement end section and said non-clamping section having a second engagement end section;
• a second rotor for winding as a winding shaft, said second rotor being arranged in cooperative relationship with said first rotor, said second rotor having a holding piece for engaging said second engagement end section to move said non-clamping section of said coil spring into engagement with said shaft section to increase torque applied to said shaft section, and said second rotor having a releasing piece arranged in spaced relation to said holding piece for engaging said first engagement end section to loosen said clamping section of said coil spring to decrease torque applied to said shaft section, said holding piece and said releasing piece cooperating to increase torque applied by said non-clamping section and to decrease torque applied by said clamping section for applying a prescribed fixed total torque by said coil spring to said shaft section.

A winder for winding a wound member such as a tape, a spring, or a wire, comprising:

• a first rotor for winding as a winding shaft, said first rotor having a shaft section, said shaft section having an outer circumferential surface;
• a coil spring engaging said shaft section, said coil spring including a clamping section engaging said shaft section and a non-clamping section arranged in spaced relation with said shaft section, said clamping section having a first engagement end section and said non-clamping section having a second engagement end section;
• a second rotor for transmitting a driving force from a driving source, said second rotor being arranged in cooperative relationship with said first rotor, said second rotor having a holding piece for engaging said second engagement end section to move said non-clamping section of said coil spring into engagement with said shaft section to increase torque applied to said shaft section, and said second rotor having a releasing piece arranged in spaced relation to said holding piece for engaging said first engagement end section to loosen said clamping section of said coil spring to decrease torque applied to said shaft section, said holding piece and said releasing piece cooperating to increase torque applied by said non-clamping section and to decrease torque applied by said clamping section for applying a prescribed fixed total torque by said coil spring to said shaft section.

A tape winder for a tape recorder, comprising:

• a fast-forward gear having a first axis;
• a rotary cylinder mounted on said fast-forward gear and extending upwardly from said fast-forward gear along said first axis, said rotary cylinder having an outer circumferential surface;
• a head-cap mounted on said rotary cylinder, said head-cap being adapted to detachably attach a reel thereto, said head-cap having a base section, said base section including an inner circumferential surface, a space being defined between said inner circumferential surface and the outer circumferential surface of said rotary cylinder;
• a main gear having a second axis and adapted to be driven by a tape recorder motor;
• a second cylinder mounted on said main gear, said second cylinder extending upwardly from said main gear along said second axis and terminating at an upper circumferential end surface, said second cylinder being slidably-fitted in said space between the outer circumferential surface of said rotary cylinder and the inner circumferential surface of said base section of said head-cap of rotation about said rotary cylinder, said second cylinder having an inner circumferential surface;
• a coil spring engaging said rotary cylinder, said coil spring including a clamping section circumferentially engaging said outer circumferential surface and a non-clamping section arranged in spaced circumferential relation with said outer circumferential surface, said clamping section having a first engagement end section and said non-clamping section having a second engagement end section;
• a holding piece mounted on said inner circumferential surface of said second cylinder for engaging said second engagement end section to move said non-clamping section of said coil spring into engagement with said outer circumferential surface of said rotary cylinder to increase torque applied to said rotary cylinder;
• and a releasing piece mounted on said upper circumferential end surface of said second cylinder for engaging said first engagement end section to loosen said clamping section of said coil spring to decrease torque applied to said rotary cylinder, said holding piece and said releasing piece cooperating to increase torque applied by said non-clamping section and to decrease torque applied by said clamping section for appling a prescribed fixed total torque by said coil spring to said rotary cylinder.