Coil diameter control system

Claim 1

In an apparatus of the type in which strip material passes a bridle means and a rotating mandrel about which it is wound and unwound, having the improvement for automatically stopping the rotation of said mandrel and the coil wound thereon when a preselected coil diameter has been achieved, said improvement comprising: a. comparator logic means and at least one angle preset, said comparator logic means adapted to receive input angle data, to compare said input angle data to said angle preset upon receipt of a comparison enabling signal, to respond with first and second output reset signals when said comparison is not satisfied and to respond with output control signals when said comparison is satisfied; b. input interfacing means associated with said angle preset for establishing said preselected coil diameter, said preselected coil diameter defining in conjunction with said angle preset, a preselected coil diameter arc-length equivalent; c. down-counting means communicating with said input interface means and preset thereby at said preselected coil diameter arclength equivalent, said down-counting means adapted to generate and transmit said comparison enabling signal to said comparator logic means upon achievement of a zero count and to thereafter be reset to said preselected coil diameter arc-length equivalent by said first reset signal from said comparator logic means. d. first pulse generating means in association with said bridle means, said first pulse generating means transmitting pulses to said down-counting means reflecting strip travel past said bridle means; e. second pulse generating means in association with said mandrel, said second pulse generating means outputting pulses proportional to the rotation of said mandrel; and f. up-counting means adapted to count said output pulses from said second pulse generating means, said count representing the angle subtended by said preselected coil diameter arc-length equivalent as wound into a coil upon said mandrel, to continuously apply said count to said logic comparator means, and to be reset by said second reset signal; whereby, said comparator logic means compares said angle preset to said count representing said subtended angle upon enablment by said comparison enabling signal, said comparator logic meAns repetitively resetting said downcounting means and said upcounting means until said comparison is satisfied whereupon, said comparator logic means initiates said output control signal for terminating mandrel rotation.