| 摘要 |
<p>1,017,397. Valves. SENCO PRODUCTS Inc. Aug. 14, 1962 [July 9, 1962], No. 31126/62. Heading F2V. A valve 37 for controlling the applications of fluid under pressure to the piston 48 of a stapler comprises a piston having a limited axial movement within a chamber and two sides of different area so that equal fluid pressure applied to both sides moves the piston in one direction while reduction in pressure on the side of greater area causes the piston to move in the opposite direction, the smaller-area side of the piston forming a valve member to cooperate with a seat 29. When a manuallyoperated lever 24 raises a pilot valve 22 communication between an air supply chamber 13 and the space above the valve member 37 is interrupted by lands 22 closing ports 20. Further upward travel of the pilot valve connects the ports 20 with exhaust passages 56, 57 so that the pressure in the chamber 13 acting on the lower side of the valve member 37 lifts it from the seat 29, the movement being accelerated once the valve is clear of its seat. The air supply now forces the piston 48 and its driver 49 down on to a resilient stop 46, uncovering ports 53 to permit air to flow past a reed 54 into a storage space 51. When the lever 24 is released, air in chamber 13 forces the pilot valve downwards and again enters the space above the valve 37 which has an interior seal 40 co-operating with a fixed stem 33 provided with exhaust ports 43. The latter are thus opened and air from the storage space 51 flows through passages 52, 47 to raise the piston 48 to its original position where it may be held by a spring detent in a magnet. An insertion washer 41 mounted for relative movement on the valve 37 co-operates with the seat 29.</p> |
