| 摘要 |
<p>1,050,327. Fluid pressure apparatus. SPHERE INVESTMENTS Ltd. Aug.24, 1965. No.36204/65. Addition to 944, 366. Heading F1P. An hydraulically controlled air cylinder comprises a tubular piston rod 13 fixed to an air piston 14 reciprocable in a cylinder 10 in response to air pressure alternatively supplied to chambers 17, 20 on either side thereof through ports 19, 22, and hydraulic means for controlling the speed of the piston 14 consisting of a tube 24 movable with the rod 13 and closed at its ends by floating pistons 28, 51 which define with a fixed piston assembly 37 two variable volume oil-filled chambers 49, 50 arranged to empty and fill one into the other at a controlled rate through passages 41, 47, 48 in the piston assembly 37 during movement of the rod 13. The piston assembly comprises members 38, 39 carried by a stationary rod 33 and an annular seat member 40 movable by the oil in the chambers 49, 50 into contact with one or other of surfaces 44, 46 thereon. The surfaces 44, 46 are provided with slots 47, 48 which thereby provide restricted communication between the chambers 49, 50. The floating piston 51 is subjected to the pressure of air in the chamber 20 during extension of the rod 13 whereby oil is forced from the chamber 50 to the chamber 49 until the floating piston 28 abuts the end 15 of the rod 13. Similarly the floating piston 28 is subjected to the pressure in the chamber 17, during retraction of the rod 13, through a port 32a in the rod 13 and an annular passage between the rod 13 and the tube 24 whereby the piston 51 is caused to abut on end cap 26 of the piston 14.</p> |
