Diffuser positioning device

Claim 1

IN A WIND TUNNEL HAVING A DIFFUSER SECTION, A PAIR OF MOVABLE DIFFUSER WALLS DISPOSED WITHIN SAID DIFFUSER SECTION DEFINING A DIFFUSER THROAT THEREBETWEEN, EACH OF SAID WALLS HAVING A POSITIONING APPARATUS FOR CONTROLLING THE MOVEMENT THEREOF, SAID APPARATUS COMPRISING: (A) A STATIONARY PLATE POSITIONED ADJACENT SAID DIFFUSER SECTION; (B) AN HYDRAULIC CYLINDER POSITIONED ON SAID PLATE, SAID CYLINDER HAVING A FIRST PORT ADJACENT ONE END THEREOF AND A SECOND PORT ADJACENT THE OPPOSITE END THEREOF; (C) A PISTON DISPOSED FOR AXIAL MOVEMENT WITHIN SAID CYLINDER, SAID PISTON BEING ADAPTED TO FORM A COMPLETE SEA WITH THE INTERIOR WALL AND CYLINDER; (D) A FORCE TRANSMTTING MEANS HAVING ONE END ATTACHED TO SAID PISTON AND THE OTHER END PIVOTALLY CONNECTED WITH SAID MOVABLE WALL; (E) A FIRST CONDUIT CONNECTED IN FLUID COMMUNICATION WITH SAID FIRST PORT FOR FOLLOWING FLUID TO FLOW INTO SAID CYLINDER SO AS TO CAUSE MOVEMENT OF SAID PISTON IN A FIRST DIRECTION (F) A SECOND CONDUIT CONNECTED IN FLUID COMMUNICATIONS WITH SAID SECOND PORT FOR ALLOWING FLUID FLOW FROM SAID CYLINDER; (G) A VALVE MEANS POSITIONED IN SAID SECOND CONDUIT FOR OPENING SAID CLOSING SAID SECOND CONDUIT; (H) A MICROSWITCH OPERATIVELY CONNECTED FOR MOVEMENT WITH SAID FORCE TRANSMITTING MEANS; (I) A SOURCE OF POWER CONNECTED TO SAID MICROSWITCH; (J) MEANS CONNECTED TO SAID MICROSWITCH; AND (K) MEANS CONNECTED IN SERIES WITH SAID MICROSWITCH FOR CLOSING SAID VALVE MEANS RESPONSIVE TO CLOSING OF SAID MICROSWITCH THEREBY HYDRAULICALLY PREVENTING FURTHER MOVEMENT OF SAID PISTON IN SAID FIRST DIRECTION WITHIN SAID CYLINDER.