摘要 |
<p>A pneumatic double two-channel drive system for a pneumatic linear power unit (10) is redundant and each movement of all components that may seriously malfunction is monitored. The system comprises two essentially identical units (1, 1') where each unit includes a drive device that is actuated by a control signal, for instance a drive signal generated by respective hands of the operator. The drive device (3) of one unit (1) delivers a start pulse and a holding signal for a power valve (6, 6') in the other unit (1") and vice versa. Each of the two power valves (6, 6') drives a monitoring valve (7, 7') and controls the supply of fluid to the power unit (10). Each unit includes an accumulator (4, 4') which is adapted to be charged when the system is at rest and discharged by actuation of respectice drive devices (3, 3'). The accumulator (4, 4') delivers a start pulse of limited duration, for actuation of one of the power valves. The system is connected to permit activation of the power unit (10) solely when the control pulses are delivered essentially simultaneously. <IMAGE></p> |