Apparatus for monitoring and controlling thread tensioning force in a sewing machine
OwnerMartin J. Foleyinventor
Life of this patent
Estimating the term…
Abstract
A thread tensioning device or apparatus for a sewing machine enables accurate, repeatable measurement and monitoring of the compression forces applied to the thread tensioning discs thereof. The apparatus further includes a visual display or output corresponding to the actual amount of compressive force being applied. The device further includes a comparator, which compares the electrical signal to a predetermined reference value to control or regulate the normal operation of the sewing machine.
Claims8
A thread tensioning apparatus for a sewing machine comprising:
- a pair of clamping members movably mounted in juxtaposition with one another and the thread when passing from the source to the station, the clamping members being movable towards one another and into clamping relation with the thread passing therebetween,
- an electromechanical compression load cell disposed in contacting relation against one of said clamping members, said load cell being separate and apart from said clamping members and operable under compression to generate an output signal representative of the compressive load placed on said load cell,
- a force member for biasing the other of said clamping members towards said one clamping member and against said thread, said thread being squeezed between said clamping members and said one clamping member being forced against said load cell wherein to place a compressive force on said load cell, and
- adjusting means for increasing or decreasing the compressive force applied by said force member against said load cell.
A tensioning device for a sewing machine for monitoring and adjusting the tension in a thread passed through the machine during a stitching operation, which comprises:
- a support shaft having proximal and distal ends, respectively, connected to and spaced from a support wall of the sewing machine,
- a ring shaped electromechanical load cell, the load cell being mounted on said shaft and disposed against said support wall, said load cell being operable to generate an output signal representative of the amount of compression placed thereon,
- a pair of centrally apertured discs, the discs being mounted on said shaft with one said disc being disposed against said load cell, the thread being routed between and engaged by the discs,
- an adjustment knob threadably connected to the distal end of said support shaft,
- a resilient helical coil spring disposed about said shaft, said spring having opposite end portions with one and the other of said end portions, respectively, engaging the other of said disc members and said adjustment knob, movement of said knob towards said support wall driving said spring and said disc members against the load cell and compressing said load cell, and
- means for receiving and displaying said output signal.
Dependencies are inferred from the claim text.