Apparatus for the preservation and regeneration of insulating oil for electrical apparatus provided with an oil reservoir

Claim 1

APPARATUS FOR PRESERVING AND REGENERATING INSULATING LIQUID FOR LIQUID-COOLED ELECTRICAL DEVICES HAVING AN INSULATING LIQUID EXPANSION RESERVOIR COMPRISING, AN EXPANSION CYLINDER, MEANS PROVIDING A COMMUNICATION BETWEEN SAID CYLINDER AND SAID DEVICE AND MEANS FOR PROVIDING COMMUNICATION BETWEEN SAID CYLINDER AND SAID RESERVOIR, A PISTON RECIPROCABLE IN SAID CYLINDER IN RESPONSE TO VOLUME VARIATIONS OF SAID INSULATING LIQUID IN SAID DEVICE, FIRST VALVE MEANS OPERABLE BY SAID PISTON TO AN OPEN POSITION ALLOWING LIQUID TO FLOW INTO SAID RESERVOIR WHEN THE LIQUID IN SAID DEVICE EXPANDS AND OPERABLE BY SAID PISTON TO A CLOSED POSITION WHEN THE LIQUID IN SAID DEVICE CONTRACTS, ONE-WAY VALVE MEANS CONNECTED TO ALLOW LIQUID TO FLOW FROM SAID RESERVOIR THROUGH SAID MEANS PROVIDING COMMUNICATION BETWEEN SAID CYLINDER AND SAID RESERVOIR TO SAID CYLINDER TOWARD SAID DEVICE WHEN THE LIQUID CONTRACTS, A PUMP IN COMMUNICATION WITH SAID DEVICE AND SAID RESERVOIR, AND MEANS FOR OPERATING SAID PUMP INTERMITTENTLY IN RESPONSE TO PRESELECTED POSITIONS OF SAID PISTON FOR CAUSING SAID PUMP TO PUMP LIQUID FROM SAID RESERVOIR TO SAID DEVICE TO MAINTAIN A PRESELECTED VOLUME OF INSULATING LIQUID IN SAID DEVICE.