Patent GB-1466942-A (GB)
Title: Printing systems
IPC: B41F33/16
Filed: 1974-03-05
Abstract: 1466942 Printing machines ADDRESSOGRAPH MULTIGRAPH CORP 5 March 1974 [21 May 1973] 9940/74 Heading B6C A printing system includes a planographic master producing portion, e.g. an electrostatic copier, a cyclically operable printing portion, a transport for transferring the masters from the producing portion to the printing portion, and a circuit, which counts the number of masters produced and gives a signal when a predetermined number have been counted, this signal being applied to control means which so controls the master producing portion that no more than the predetermined number is ever present in the system. As shown, the circuitry utilizes portions of the control circuitry of both the master producing portion and the printing portion, and is based on impulse sequencing relay 30. Relay 32 is connected to assembly 30, and controls circuits whereby an original document is accepted by the master producing portion each time this relay is pulsed. The relay contacts 34a to 34e are associated with a relay or relays (not shown) operated in response to a signal indicating presence of a master on the printing cylinder of the printing portion. Relay 38 is arranged, each time it is pulsed, to operate pawl 40 and thereby index wheel 42. Wheel 42 carries shaft 44, which shaft bears cam surfaces 46 and 50 co-operating with switch members 48 and 52 respectively. Leads 56, 58, 60 and 62 are connected to the printing portion circuitry, lead 56 to A.C. power supply, leads 58 and 62 to A.C. power via a cam-operated switch arrangement to provide a train of pulses, one for each printing cylinder revolution, and lead 60 is connected to A.C. power at all times when the machine is on. Leads 64 and 66 are connected to the master producing portion circuitry, lead 64 to the negative D.C. power, and lead 66 to positive D.C. power via a circuit which detects when both (a) the printing portion is ready to accept a master and (b) an original has been inserted into the producing portion, and which circuit then becomes conductive. When the system is started the coil 38 is energized from lead 58 and steps wheel 42 since switch member 48 is in contact with contact 48a as shown. This step opens contacts 48, 48a, and closes contacts, 48, 48b and 52, 52a. Therefore power at lead 66, via closed contact 34d and closed contacts 52a and 52 pulses relay coil 32 and thereby feeds the original to the producing portion. Pulsing of relay 32 also momentarily closes contacts 32a and therefore, via closed contacts 48, 48b pulses relay coil 38, so indexing wheel 42. Subsequent introduction of originals will each produce the same result. Until the first master reaches the printing cylinder, contacts 34d remain closed. When the fourth master is produced the cam surfaces open contacts 52, 52a and thereby prevent pulsing of contacts 32a so preventing stepping of the wheel 42. When the first master reaches the printing cylinder and its presence is sensed, the relays transfer contacts 34a, 34e to the opposite condition. Pulses from line 62 will then index wheel 42 until cam surfaces open contacts 48, 48b so resetting the system.