Thread use monitor

Claim 1

Apparatus for sensing improper operation of a machine which utilizes thread-like elements in a substantially repetitive cycle comprising: A. Sensing means which generate a signal relative to the length of the element actually used during each operative cycle of the machine; B. Means for generating a predetermined signal relative to the average length of thread used during a normal cycle of the machine; and C. Analyzing means which receive the actual signal and the normal signal and generate an alarm signal relative to the difference between said normal and actual signals.

Claim 3

A device for detecting improper threAd use in an average stitching cycle of a sewing machine comprising: A. a rotary tension device mounted on the sewing machine having a pulley element about which the thread passes in frictional engagement which causes the pulley to rotate as the thread is fed to the needle; B. a disk mounted on the pulley for rotation therewith, said disk having apertures uniformly spaced about its periphery; C. photoelectric means responsive to light radiated through the disk apertures to generate pulses as the disk rotates, the sum of said pulses being proportional to the length of thread being used; D. a first counter for summing the pulses received from the photoelectric means, and for passing a signal after a preset sum has has been reached; E. pulse generating means operatively associated with the sewing machine drive to generate pulses proportional to the number of sewing cycles in an operation of the machine; F. a second counter for summing machine cycle pulses and for passing a signal after a preset number of cycles have been performed; G. gating means responsive to the signals passed from the first and second counters to pass an alarm signal when the first counter indicates that the preset sum has not been reached during the preset number of cycles summed by the second counter; and H. a warning device responsive to the alarm signal to notify a machine operator that a malfunction has occurred.

Claim 4

A device for detecting improper threAd use in an average stitching cycle of a sewing machine comprising: A. a rotary tension device mounted on the sewing machine having a pulley element about which the thread passes in frictional engagement which causes the pulley to rotate as the thread is fed to the needle; B. a disk mounted on the pulley for rotation therewith, said disk having apertures uniformly spaced about its periphery; C. photoelectric means responsive to light radiated through the disk apertures to generate pulses as the disk rotates, the sum of said pulses being proportional to the length of thread being used; D. a first counter for summing the pulses received from the photoelectric means, and for passing a signal after a preset sum has has been reached; E. pulse generating means operatively associated with the sewing machine drive to generate pulses proportional to the number of sewing cycles in an operation of the machine; F. a second counter for summing machine cycle pulses and for passing a signal after a preset number of cycles have been performed; G. gating means responsive to the signals passed from the first and second counters to pass an alarm signal when the first counter indicates that the preset sum has not been reached during the preset number of cycles summed by the second counter; and H. a warning device responsive to the alarm signal to notify a machine operator that a malfunction has occurred.