Blank feeding apparatus

Claim 1

Apparatus for feeding blanks of paperboard or the like one after another from a stack of blanks to processing rolls, said apparatus comprising: an endless conveyor means disposed under said stack of blanks for feeding blanks one after another from said stack to said processing rolls, at least one kicker means secured on said endless conveyor means for pushing the rear end of the blank at the bottom of said stack toward said processing rolls, motor means for driving said conveyor means, a first transducer means for generating pulses (φ A ), the number thereof being proportional to the distance the surface of one of said processing rolls has rotated, a second transducer means for generating pulses (φ B ), the number thereof being proportional to the distance the conveyor means has travelled, a sensor for detecting said kicker and giving a signal, a first setting means for setting a first value (Lo) determined by the circumference of said one of said processing rolls and a second value (B o ) determined by the distance the kicker travels during one cycle, a second setting means for setting a third value (l 2 ) determined by the distance the kicker travels during the time from the operation of said sensor to the stopping thereof, computation control means for receiving said first and second values and the pulses from said first transducer means and the pulses from said second transducer means and performing a computation expressed by (Lo-Bo-φ A +φ B ), to determine an error signal, combining means for combining together said error signal and a voltage proportional to the signal from said first transducer means, stop control means responsive to the signal from said sensor for subtracting the pulses from said second transducer from said third value, means for selecting the higher one from the two signals, that from said combining means and that from said stop control means, and comparing it with a voltage proportional to the speed of the conveyor means and producing a speed command signal proportional to the difference therebetween, and motor control means for receiving said speed command signal to control said motor means so that one cycle of kicker operation will be completed while said one of said processing rolls makes a full turn, said one cycle including the acceleration, tuned-run and deceleration periods.