Device for measuring the thickness of objects to be handled in document-handling machines

A method of measuring the thickness of documents to be engaged between a relatively stationary back-up part and a pivotable gripper jaw of a mail-processing machine having a plurality of processing stations, said method including the steps of:

• using a raster gage to detect raster marks and generate a train of pulsed position signals corresponding to predetermined amounts of motion of said pivotable gripper jaw relative to said back-up part and indicating the direction of said motion;
• delivering said position signals to an UP/DOWN-counter to control incrementation or decrementation of said UP/DOWN-counter and generate a digital signal representative of the state of said UP/DOWN-counter at any given time;
• transforming said digital signal to an analog signal;
• amplifying said analog signal;
• delivering said amplified signal to a voltage-controlled oscillator for producing an output frequency corresponding to the position of said gripper jaw relative to said back-up part;
• and,
• controlling said output frequency to make said output frequency the same as other output frequencies from other respective processing stations which engage respective documents having respective nominal thicknesses.

A mail-processing device for measuring the thickness of documents to be engaged between a relatively stationary back-up part and a gripper jaw of a mail-processing machine having a plurality of processing stations, said device comprising:

• A measuring signal generator for providing position-detector signals corresponding to predetermined positions of said gripper jaw in relation to said back-up part, said measuring signal generator further comprising:
• A raster gage having raster marks for providing a reference by which relative movement between said relatively stationary back-up part and said gripper jaw of said mail-processing machine can be measured;
• A detector assembly mounted opposite said raster gage for detecting said raster marks, said detector assembly being adapted to produce a train of pulsed output signals including information regarding the direction of said relative movement;
• An UP/DOWN-counter operatively connected to said detector assembly such that said output signals of said detector assembly control incrementation or decrementation of said UP/DOWN-counter;
• means for using said count to produce an output frequency corresponding to the position, of said gripper jaw relative to said back-up part;
• means for controlling said output frequency to make said output frequency the same as other output frequencies from other respective processing stations which engage respective documents having respective nominal thicknesses;
• and,
• an actuator system operatively connected between said back-up part and said gripper jaw for generating movement of said gripper jaw between an engagement position and an open position in relation to said back-up part.