Control device for a mechanism located in a casing

Claim 1

IN AN INSTRUMENT COMPRISING A MOVEMENT ENCLOSED IN A CASING, IN COMBINATION, A CASING PART HAVIN A SUBSTANTIALLY CYLINDRICAL SURFACE HAVING PART OF A PASSAGE EXTENDING ACROSS THE CASING WALL, A STEM EXTENDING THROUGH SAID PASSAGE SUBSTANTIALLY COAXIALLY THERETO AND BEING ADAPTED FOR TRANSMITTING MOTIONS FROM OUTSIDE THE CASING TO THE MOVEMENT ENCLOSED THEREIN, A FIRST PART SECURED TO SAID STEM AND HAVING A CYLINDRICAL PORTION EXTENDING IN SAID PASSAGE SUBSTANTIALLY COAXIALLY TO THE CYLINDRICAL SURFACE THEREOF AND IN SPACED RELATION THEREWITH, A SHOULDER ON SAID FIRST PART EXTENDING TRANSVERSELY FROM ONE END OF SAID CYLINDRICAL PORTION THEREOF TOWARD THE CYLINDRICAL SURFACE OF SAID PASSAGE, AN ANNULAR SEALING GASKET SURROUNDING THE CYLINDRICAL PORTION OF SAID FIRST PART AND ENGAGING THE CYLINDRICAL SURFACE OF SAID PASSAGE, AND A SECOND PART INCLUDING A CONTROL MEMBER AND A PRESSING MEMBER AND BEING FIXED TO SAID FIRST PART FOR ROTARY MOTION BUT SHIFTABLE WITH RESPECT THERETO BETWEEN TWO AXIAL POSITIONS: A WORKING POSITION, IN WHICH SAID PRESSING MEMBER IS REMOVED FROM SAID SEALING GASKET, AND A CLOSING POSITION IN WHICH SAID PRESSING MEMBER STRONGLY PRESSES SAID GASKET AGAINST SAID SHOULDER THEREBY CAUSING SAID GASKET TO BE STRONGLY PRESSED BOTH AGAINST THE CYLINDRICAL PORTION OF SAID FIRST PART AND THE CYLINDRICAL WALL OF SAID PASSAG.