GB948924A - Hydraulic laundry press - Google Patents

Abstract

948,924. Ironing presses. McGRAWEDISON CO. May 6,1960, No. 16201/60. Heading D1A. A laundry press is closed under light pressure by an air-operated cylinder-piston unit 17 and under heavy pressure by a booster unit 13 comprising a hydraulic cylinder 28 (Fig. 2) and piston 16a, and a pneumatic cylinder 24 and piston 23a carrying a ram 23 adapted to exert hydrostatic pressure on the piston 16a. As the press approaches fully open and fully closed positions a snubbing action is exerted by a part 16c of piston rod 16 entering a small clearance bore 31a. In operation, by manually opening valves 50, 51, air from line 48 is passed to line 54 to open a valve 56 and allow air through line 57 to operate the unit 17 to lower the press head 21. During the first half of the press closing movement, the piston rod 16 is pushed down and liquid is displaced from one side of piston 16a to the other through a bore 29a, ports (59 in Fig. 5, not shown) in a casting 26, a reservoir 35, ports 60, and a check valve 58, and also through bore 31a after part 16c has been withdrawn. In the second half of the press closing movement the piston 16a is pulled upwardly, the liquid flow is reversed, and valve 58 is closed. The bore 31a however allows substantial flow until closed by the part 16c to produce the snubbing action. Flow is now through an adjustable needle valve 61. When the press reaches lightly closed position, the piston of unit 17 opens a port to allow air to flow through a line 62 to operate a slide valve 46. This supplies air through line 63 to the lower side of piston 23a and cuts off the supply through 45 to the upper side. The ram 23 now advances and cuts off liquid flow at a seal 30 and produces an increased pressure on the piston 16a and press head 21. The reservoir 35 has a flexible wall 33 to accommodate slight liquid displacement during the final high pressure piston stroke. By operating a release valve 64, valve 46 is restored to the position shown, thereby reversing air supply to the booster unit 13. This allows piston 16a to descend and springs 49 to reopen the press. Specification 944,558 is referred to.