Fluidic machine cycle control

Abstract

A press control includes a pair of pushbuttons each operating a pneumatic pump means to form a pair of signal pulses and an integrated valve to form a pair of binary logic pressure signals. A press position sensor provides a binary pressure signal related to the press position. The pushbutton and sensor signals are connected to fluidic logic gate means to compare and detect the actuation of the pushbuttons as well as the status of such pushbuttons and the press cycle. The logic output is connected by a plurality of logic gates to actuate a flip-flop output unit to generate an extend output or a retract output. The flip-flop output unit has an input connected to a latch input control to provide automatic reset to the retract output if release of the button signal sources occurs during a hazardous portion of the extend cycle. Once the non-hazardous portion of the extend cycle is reached, the latch is complete for the terminal portion of the extend cycle. A fluidic fuse in the form of a diaphragm comparator monitors the extend output and the operation of the pushbuttons and automatically responds to terminate press operation if the logic signal outputs of the pusbuttons are not formed prior to creation of the extend signal. After creating of the extend cycle, a special bleed system permits release of the pushbuttons after the hazardous portion of the extend cycle is complete.