Paper sheet counting machine provided with safety device

A paper sheet counting machine comprising:

• a paper sheet counting mechanism including a holder for receiving a bundle of paper sheets, suction cylinders for turning over the paper sheets one by one and a counting circuit for counting the number of paper sheets turned over the suction cylinders;
• a pair of double leaf type sound-proof covers made movable between an open position for providing easy access to said holder and a closed position at which said sound-proof covers extend above the section containing said paper sheet counting mechanism;
• a motor for closing said sound-proof covers after said holder receives said paper sheets and for opening the covers after the completion of the counting operation;
• and
• control means for controlling to actuate or stop said motor and including a first comparator for comparing the actually counted number with a preset number to generate a signal for actuating to rotate said motor in the opening direction when the actually counted number is coincident with the preset number, a start signal output circuit for generating a signal for actuating to rotate a holder motor in the closing direction when a bundle of paper sheets to be counted is put on said holder, a delay circuit for receiving the signal from said start signal output circuit to generate a delayed signal, a timer for receiving said delayed signal to generate an operation signal after a preset time interval, a second comparator for receiving a signal from a cover position sensor and said operation signal from said timer to generate an abnormal detection signal if it is not fed with said signal from said cover position sensor even after said operation signal is received, and a gate circuit for receiving said delayed signal and a signal from said second comparator to actuate said motor for closing said sound-proof covers, said gate circuit being rendered inoperative when it receives said abnormal detection signal from said second comparator.