| 摘要 |
1,239,062. Valves. OTIS ENG. CORP. 6 Nov., 1968 [17 May, 1968], No. 52473/68. Heading F2V. A rotatable plug valve comprises a valve member 15 which is rotatably mounted by trunnions 20, 21, and operated by a rectilinear fluid motor 40 coupled to the trunnion 21 through a mechanism which transforms the rectilinear into the rotary movement. A sleeve 65 coupled to the trunnion is rotated by a cross pin 70 sliding in axial guides in the sleeve and in helical slots in a fixed sleeve 58. The cross pin is mounted, by a head 72, thimble 75, and bearings 80, rotatably on a pin 78 fixed to the piston-rod 54. The valve is locked in the closed position by a spring-loaded pin 116 engaging ratchet teeth in the sleeve 65. The valve is also arranged to " fail-safe " in the event of loss of operating pressure or overpressure within the valve. This is effected by the spring 50 or by the pressure within the valve having access to a plunger 140 through a passage 131 communicating with the plug bore. The valve can further be operated manually by a handle 30. Known lubricating devices 29 are provided. A breather cap 107 and relief valve 105 are provided on the motor. In a modification, the motor shown is replaced by a diaphragm type motor. If the plunger 140 is removed, the bore 130 may be closed by a screwed plug. |
