Anyone who sews knows how annoying it is when the bobbin runs out of thread--especially when you only notice a few hundred stitches later. Pins get removed, and the abrupt end in thread can't be backstitched.

A small rotation sensor installed in the bobbin's spindle detects when the bobbin no longer turns when the machine is running. It can trigger an alarm, or bring the stitching to a halt. The user can then rewind the bobbin without losing their place in the fabric.

More advanced models can measure the amount of bobbin thread dispensed (accounting for the decreasing diameter of the winding), and can alert the user right before the thread is expected to end. Even a countdown of linear stitches remaining could be displayed.
-- Aq_Bi, Jul 09 2008

This is baked crispy. Google "low bobbin indicator."
-- nomocrow, Jul 09 2008


Perhaps then, [nomocrow], the idea could be modified to be an apple sensor for the edge of a water-filled tub to alert you when your... wait for it... bobbin for apples.
-- Cedar Park, Jul 10 2008


Maybe it could be used as a motion sensor to help you detect punches. This would help boxers perfect their bobbin weave.
-- nomocrow, Jul 10 2008


Blimus!, [Aq_Bi], Where you been?
-- gnomethang, Jul 10 2008



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