DEVICE FOR CONTROLLING WORKING CYLINDERS DURING THE Digging OF UNDERGROUND WORKS AND THE LIKE, AND PARTICULARLY FOR CONTROLLING HYDRAULIC PUSH CYLINDERS DURING THE Digging BY MEANS OF A SHIELD

摘要

P THE INVENTION RELATES TO A DEVICE FOR CONTROLLING A GROUP OF DOUBLE-ACTING HYDRAULIC WORKING JACKS, INCLUDING A MULTI-CURRENT PUMP BLOCK WHICH PROVIDES SEVERAL PARTIAL HYDRAULIC CURRENTS, CHARACTERIZED IN THAT - DUCTS PARTIAL CURRENT PRESSURES 231 TO 238 ARE CONNECTED TOGETHER BY FORMING A HYDRAULIC SYSTEM COMMUNICATING TO THE PRESSURE CHAMBERS 32 OF THE WORKING JACKS 9 WHICH ARE CONNECTED TO THEM, THE PARTIAL CURRENT PRESSURE CONDUITS THAT CAN BE RESPECTIVELY CLOSED IN RELATION TO THE SYSTEM SWITCHING VALVES 251 TO 258 WHICH ARE CLEAN; - A PRESSURE LIMITATION VALVE 371 TO 378 WHICH IS SPECIFIC TO EACH AND WHOSE RESPONSE PRESSURE IS ADJUSTABLE IS RESPECTIVELY ASSOCIATED WITH EACH OF THE PRESSURE DUCT CURRENT 231 TO 238. /P