LOCKING MECHANISM OF AIR-OPERATED NORMALLY-CLOSED VALVE FOR GAS CYLINDER UNIFIED WITH DISPLAY MECHANISM FOR INDICATING OPENING OF VALVE

摘要

PURPOSE: A locking mechanism of an air-operated normally-closed valve for a gas cylinder is provided to visually display an opening state of the valve that the air contained in the gas cylinder is in use by a display mechanism. CONSTITUTION: A locking mechanism of an air-operated normally-closed valve(20) for a gas cylinder(10) is composed of a housing(21) separably attached to a valve port(12a) of the gas cylinder; a piston assembly(30) disposed in the housing and biased by power of a spring(15) for moving a valve body(13) in the direction of closing the valve port in attaching the valve port to the housing; a taper shaft member positioned coaxially with a shaft of the piston assembly at the opposite side of the valve port and formed with an annular outer taper surface having the diameter getting narrowed apart from the valve port; a locking nut(25) screw-engaged with the housing to be coaxial with the taper shaft member; an annular inner taper surface(25t) formed at the inner peripheral surface of the locking nut to correspond to the annular outer taper surface; a middle cylinder member(21h) integrated with the housing, positioned between the annular inner and outer taper surfaces, and formed with at least one of radial through-holes; and at least one locking piece(27) inserted in the radial through-hole to move freely in the radial through-hole and contacted with the annular inner and outer taper surfaces. The locking nut locks the piston assembly by pressing the locking piece for the annular outer taper surface through the annular inner taper surface and changing the screwing of the locking nut.