Doubles and thickness detector and sorter

An automatic double or thickness detecting sheet handling apparatus, comprising:

• means for delivering consecutive sheet materials to a drum;
• a rotatable drum for receiving and discharging each sheet material as the drum is caused to rotate;
• first and second pivotable, elongated, spaced apart arms, said first arm disposed adjacent the rotatable drum at an incoming section thereof and said second arm disposed adjacent said drum at a discharge section thereof, each arm having a mirror supported on a distal end thereof and a roller carried on an opposite end thereof, each arm being pivotably mounted between the mirror and roller ends, each respective roller being in biased contact with said drum and being respectively movable with respect to said drum in response to sheet material passing between said drum and said respective roller;
• a light source mounted to project a light beam at the mirror carried by said first arm, said arms being arranged such that the light beam projected at said first arm mirror will reflect off said first arm mirror towards the mirror carried by said second arm, and reflect off said second arm mirror towards a photodetector;
• and
• a photodetector mounted to receive the light beam reflected off said second arm mirror and provide an indicator signal in response thereto, whereby as consecutive sheets pass between said respective rollers, a double or thicker sheet disposed between one of said respective rollers and said drum will cause that roller to move a greater distance than the other respective roller with a single sheet of proper thickness disposed between it and the drum, thereby causing one of said arms to pivot a greater amount than the other respective arm, thereby causing the light beam to reflect off said respective first and second arm mirrors such that said photodetector will not receive said light beam, thereby indicating a double or thicker sheet disposed between one of said rollers and said drum.