Venetian blind and the like

Claim 1

VENETIAN-TYPE BLIND COMPRISING A PLURALITY OF SLATS PROVIDED WITH OPENINGS FOR A LIFTING TAPE; A DRIVABLE WIND UP SHAFT; A WIND-UP DRUM RIGIDLY SUPPORTED BY SAID SHAFT AND INCLUDING A HUB; A LIFTING TAPE ENGAGEABLE WITH THE LOWERMOST ONE OF SAID SLATS EXTENDING UPWARD THROUGH SAID OPENINGS, AND WINDABLE UPON SAID DRUM; SWIVEL FRAME MEANS SEATED FOR FRICTIONAL CONTACT UPON SAID SHAFT THROUGH THE AGENCY OF SAID DRUM; CARRIER MEANS ENGAGING SAID SLATS AND OPERABLY CONNECTED WITH SAID SEIVEL FRAME MEANS; STOP MEANS FOR ARRESTING SAID SEIVEL FRAME MEANS IN ITS TERMINAL POSITION DURING FURTHER ROTATION OF THE SHAFT; A LOCKING MECHANISM FOR LOCKING THE SWIVEL FRAME MEANS TO THE SHAFT, COMPRISING A SPIRAL SPRING WOUND UPON SAID HUB AND HAVING A PAIR OF ANGULARLY SPACED ENDS; STATIONARY STOP MEANS FOR ENGAGING ONE OR THE OTHER OF SAID PAIR OF ENDS, DURING SAID FURTHER ROTATION, IN A DIRECTION CAUSING SAID SPRING TO OPEN UP AROUND THE HUB TO PERMIT TURNING THEREOF WHILE THE SPRING IS HELD AT REST; AND TWO ANGULARLY SPACED FURTHER STOIP MEANS, RIGID WITH SAID SWIVEL FRAME MEANS AND PIVOTING THEREWITH, AND LOCATED ADJACENT RESPECTIVE ONES OF SAID PAIR OF ENDS, FOR BEARING ON THE RESPECTIVE END IN A DIRECTION CAUSING SAID SPRING TO TIGHTEN AND LOCK ABOUT THE HUB, WHEN THE SWIVEL FRAME MEANS IS PIVOTED INDEPENDENTLY OF THE SHAFT, WHEREBY THE SEIVEL FRAME MEANS IS LOCKED TO THE SHAFT.