Bobbin thread monitor

摘要

A bobbin thread monitor includes a rotatable thread pulley together with a rotation sensing counter and numeric count display. During bobbin loading, the thread supply is looped about the pulley in a first direction resulting in rotation of the thread pulley in a corresponding first direction. The rotation of the thread pulley in the first direction produces an accumulated account within the rotation sensing and display apparatus. During sewing operations, the thread supply is looped about the thread pulley in a second opposite direction loop resulting in opposite direction rotation of the thread pulley during the sewing process. The opposite direction rotation of the thread pulley during the sewing process produces a downcount of the number accumulated during the bobbin loading process. This down count is indicative of bobbin supply remaining and may be used to activate additional alarm apparatus.

主权项

1. For use with a sewing machine having a needle thread drawn from a main thread spool and a bobbin thread wound upon a bobbin, a bobbin thread monitor comprising:
a thread pulley rotationally supported in association with a sewing machine; a rotation counter operatively coupled to said thread pulley producing a count which is increased in response to rotation of said thread pulley in a first direction and decreased in response to rotation of said thread pulley in a second opposite direction; display means for displaying said count; and thread guide means for guiding a thread used by a sewing machine to travel about said thread pulley during bobbin loading and sewing operations of a sewing machine, said thread pulley having a thread looped about said thread pulley in a first direction to cause said thread pulley to rotate in a first rotational direction during bobbin loading and in a second opposite direction during sewing operations, said rotation counter increasing said count response to said first direction and decreasing said count in response to said second direction, wherein said rotation counter includes a housing rotationally supporting said thread pulley and said display means.