| 摘要 |
A control system for presses and the like of the type having a path for insertion and removal of work pieces includes a motor operated protective shutter insertable into the work piece insertion and removal path and a photocell system defining a light controlled area arranged transversely across such path and on the operator's side of the shutter. Circuitry responsive to the condition of the photocell device controls operation of the shutter motor. Press releasing circuitry, actuable to permit initiation of a press cycle, is controlled by contacts actuable by the shutter and by timing circuitry. Operation of the timing circuitry is initiated when the light controlled area, or light curtain, becomes unoccupied, the timing circuitry operating for a short time within which the shutter initiates and completes its closing movement. Then, the press is released for initiating a press cycle, in response to the contacts sensing the closed position of the shutter and in cooperation with the timing circuitry. |
