GB876327A - A device for triggering operations in processing machines for material in the from of endless tapes or sheets of finite lengths - Google Patents

Abstract

876,327. Photo-electric control of processing operations. WALTER, F. Dec. 4, 1957, No. 37833/57. Class 40(3) [Also in Group XVI] In a device for controlling operations on strip material moving through a processing machine the operation is initiated by pulses received from a photo-electric scanner which responds to trigger markers provided on the strip material. When operations are performed at positions which are equally spaced on the strip the scanner pulses synchronize the frequency of an oscillator which supplies an output pulse to trigger the operation and when the positions are not equally spaced a delay circuit replaces the oscillator and the operations are triggered by a delayed scanner pulse. The material is moved through the processing machine by a transport mechanism 3 and pulses produced in the scanner 15 by markers 19 either pass via a delay circuit 16 to a trigger device 14 which operates a processor 12 or (as shown) synchronize the frequency of an oscillator 17 which provides an output pulse to the trigger device 14. Where the operations are equally spaced along the strip the scanner is spaced from the process point 13 an amount equal to distance 21 (marker to point of operation 18) plus any number of complete operational distances 22 and where the operations are unequally spaced a delay time is chosen during which the strip travels the distance between the scanner and processing position minus the distance between the marker and the point of operation on the strip. If an operation requires a stationary strip the trigger mechanism 14 energizes an electromagnet 9 which halts the strip by raising the pressure roller 8. In a second arrangement (Fig. 2, not shown), two scanners are provided, one permanently connected to the delay circuit and the other to the oscillator circuit.