Valve control for gas lift

Claim 1

THE COMBINATION, WITH CASING DISPOSED IN A WELL, TUBING MOUNTED CONCENTRICALLY WITHIN SAID CASING, AND MEANS FOR ADMITTING FLUID UNDER PRESSURE TO THE INTERSPACE BETWEEN SAID TUBING AND SAID CASING, OF A SERIES OF SOLENOID VALVES SPACED VERTICALLY ALONG SAID TUBING, EACH VALVE CONNECTING THE INTERIOR OF THE TUBING WITH THE EXTERIOR THEREOF TO REGULATE THE FLOW OF FLUID FROM SAID INTERSPACE INTO SAID TUBING, AND EACH VALVE BEING SOLENOID OPERATED, A SERIES OF RELAYS, ONE FOR EACH VALVE, EACH RELAY INCLUDING AN ARMATURE, A SET OF NORMALLY CLOSED CONTACTS AND A SET OF NORMALLY OPEN CONTACTS ASSOCIATED WITH SAID ARMATURE, AN OPERATING WINDING FOR ATTRACTING SAID ARMATURE TO MOVE IT TO THE NON-OPERATING POSITION, A LATCH FOR HOLDING SAID ARMATURE IN ITS NON-OPERATING POSITION, AND A SECOND WINDING FOR RELEASING SAID LATCH, SAID TUBING CONSTITUTING A GROUND CONNECTION FOR THE ELECTRICAL CIRCUIT OF SAID RELAYS, A CONDUCTOR EXTENDING FROM THE TOP OF SAID WELL TO THE ARMATURE OF THE TOP RELAY, A CONDUCTOR CONNECTING A NORMALLY OPEN CONTACT OF EACH RELAY WITH THE ARMATURE OF THE NEXT LOWER RELAY IN SAID SERIES, A LEAD CONNECTING A NORMALLY CLOSED RELAY CONTACT TO GROUND THROUGH