Patent GB-1055667-A (GB)
Title: Apparatus for supervising objects intended for movement along a path of travel
IPC: A63B39/00
Filed: 1964-03-10
Abstract: 1,055,667. Delivering sheets. GENERAL ELECTRIC CO. March 10. 1964 [April 9, 1963], No. 10120/64. Heading B6H. Objects such as sheets which are fed spaced apart along a path, are moved past a sensing means which sends a signal denoting the absence of an article to a memory means coupled to the sensing means for detecting the signal and for generating an indication if the signal is not detected during a predetermined time interval. The apparatus is devised for detecting stoppages or jamming in the feed of the objects, and for stopping the feed to prevent damage to the objects or apparatus, and is described as applied to means which sorts documents received from an electronic data processor. Documents 11a are separated from a hopper 12 by known means driven by a shaft 15 from a constant speed motor 9, and the actual separation of the documents is under the control of the associated data processor. The separated documents 11b are fed in a path past three sorting and stacking devices 19a, 19b, 19c, including rotatable suction drums 20a, 20b, 20c. Endless belts 21a, 21b, 21c are positioned around the respective drums and pulleys 22a, 22b, 22c, and the drums and belts are driven by the motor 9. An endless belt 23 is driven frictionally by the driven belts 21a, 21b, 21c, and documents from the hopper 12 are gripped between the belts and fed at constant speed. The devices 19a, 19b, 19c are operated by some control means to remove particular documents 11b from the path of travel and stack them, and any document not removed is transferred into a special compartment 26. Means for detecting whether a document 11b has halted or become jammed in the path defined by the belt 23 comprises a series of photo-electric or phototransistor devices 31-34, positioned at spaced points along the path, and which receive direct light from lamps 41-44 in the absence of a document. The devices 31-34 generate two different kinds of signals, according to whether the light beams are intercepted or not, and these high level or low level signals are amplified or converted by means 51-54 and applied to AND-gates 61-44 in a memory apparatus 60. The AND-gates will transmit a high level signal when they receive a high level signal from the devices 31-34 concurrently with a high level signal TS3 from a timing signal generator 80, and will transmit a low level signal when any one signal from the devices 31-34 or generator 80 is low level. High level signals, denoting that a document 11b is not intercepting the light beams, are recorded and stored in bi-stable multi-vibrators 71-74 which will remain in their set state, even when documents subsequently intercept the light beams, and will transmit a low level signal to an OR-gate 91 in a memory interrogator 90. The device 90 periodically interrogates the memory 60 to determine if there are any devices 71-74 not in a set state, i.e. if it locks a recording of a document absence signal, and, in addition to the OR-gate 91, includes an AND-gate 92 which receives a high level timing pulse TS4 from the generator 80, to operate through a multi-vibrator 93 a relay 8 which can open the switch 7 of the motor 9 driving the feed belts for the documents. The timing signal generator 80 functions: (1) to render the memory 60 responsive only during certain time intervals; (2) to render the interrogator 90 responsive subsequent to each time interval; and (3) to clear the memory 60 of all recordings of document absence signals ready for the next time interval. It includes a wheel 17, on the constant-speed shaft 15, with a slot 81 which can allow light from a source 83 to impinge on a sensor 82. Accordingly, high and low level signals TS1 are sent from an amplifier 84 to a multi-vibrator 85 and an AND-gate 96. The latter controls, with an external signal E, the separation of the documents from the hopper 12; the former produces signals TS2 which are inverted at 87 to signals TS3 for the gates 61-64, and signals TS4 to the gate 92 and a multi-vibrator 88. A signal TS5 is inverted at 89 to a signal TS6 which causes the multivibrators 71-74 of the memory 60 to be placed in their reset state and cleared of previous recordings. The devices 31-34 need not be evenly spaced apart. In a modification (Fig. 2, not shown), the memory 60 only includes two multi-vibrators and associated AND-gates, the devices 31, 33 being connected to one gate, and the devices 32, 34 to the other gate.