GB1308035A - Automatic control systems - Google Patents

Abstract

1308035 Counting apparatus RICOH KK 15 April 1970 [25 April 1969] 17862/70 Heading G4D When it is desired to cause a machine e.g. a photocopier, (not shown) to perform a number of cycles, shaft 25 is displaced from its normal position by knob 2 into the appropriate one of a plurality of discrete angular positions from which it is returned to the normal position in discrete steps by means of a ratchet 29 on the shaft, the arrangement being such that the number of steps required to return the shaft 25 to its normal position in which it causes closure of switch 22 is one less than the number of cycles that it is desired that the machine will perform. The closure of switch 22 enables the machine to perform one further cycle whereupon its internal control circuit automatically opens to stop the machine. An arm 3a of a lever 3 biased clockwise by a spring 31 is arranged to be depressed by a coupling member of the machine at the end of each cycle. Such depression causes a lever 30 co-pivotal with lever 3 to follow the anticlockwise movement of lever 3 through the coupling spring 32 which biases an arm 30a of lever 30 into engagement with an arm 3b of lever 3. A pawl 33 biased anticlockwise by spring 35 is thus permitted to step ratchet wheel 29 one step anticlockwise as a pin 33b of lever 30 disengages a surface 33b of pawl 33 and engages a surface 33c. Subsequently pawl 33 disengages ratchet wheel 29 and returns to the position shown. Anticlockwise movement of lever 30 also causes an arm 30c thereof to rotate a catch 38 against spring bias so that cam follower 24 drops from ledge 38a to ledge 38b thereby allowing switch 22 to open and prevent the control circuit of the machine from opening so that the next cycle is automatically initiated. The cam follower 24 remains in this position until the ratchet wheel 29 is returned to its normal position in which a non-toothed part 29a of the wheel 29 is below the pawl 33. In this position a pin 26 carried by an index wheel 27 of the shaft 25 raises the cam follower 24 to close switch 22 so that the control circuit of the machine automatically opens at the end of one further cycle. The catch 38 is returned to its initial position when the cam follower 24 is raised by pin 26. Switch 22 has a plug for connection to the machine.