Patent ID: 6378841
Filing Date: 2002-04-30
Classification: F16K

Abstract:
A quarter-turn valve comprising:a tubular body having a bore flow passage; a valve element having a through flow passage and two or more sealing surfaces, said valve element rotatable through a quarter turn about an axis transverse to said through flow passage, wherein said through flow passage is aligned with said bore flow passage to permit flow when said valve element is positioned at a first end of the quarter turn and is misaligned with said bore flow passage to prevent flow when said valve element is at a second end of the quarter turn; an actuating valve stem selectively operable through a quarter-turn input motion for effecting opening or closing of said valve element to permit or prevent flow; motion multiplication means operated by rotation of said actuating valve stem; cam means coaxial with the bore flow passage, said cam means engaged by the motion multiplication means whereby motion is transmitted to the cam means from said motion multiplication means through a direct-drive coupling; reciprocable seat means providing a seal with said sealing surfaces when in a first position and separated from said sealing surfaces when in a second position, the seat means forced between the first and second positions by movement of said cam means; and lost motion means interposed between said motion multiplication means and said valve element; whereby rotation of said actuating valve stem initiates movement of said cam means to move the seat means into the second position prior to the valve element rotation and then back into the first position upon completion of the valve rotation.