GB894455A - Oil and air pressure operated apparatus for automatically opening and shutting mud doors for use in hopper barges - Google Patents

Abstract

894,455. Door operating appliances. HAKODATE DOCK KABUSHIKI KAISHA. Nov. 2, 1959, No. 37081/59. Class 65(1). A mud door 1 in a hopper barge is connected by means of a chain or wire 3 to the piston rod 7 of a piston 8 in an oil pressure cylinder 9 so that on release of the door the weight of the mud forces the oil through a non-return check valve 10 and conduit 11 to an air pressure tank 12, the potential energy thus accumulated in the tank being utilized to return the piston 8 to its original position to close the door after discharge of the mud. A manually operated catch means 4 holds the door in its closed position. An auxiliary oil tank 34 is provided so that if insufficient pressure is available in the tank 12 to completely close the door additional oil may be pumped into the cylinder 9 by a pump 20 through a valve 19 and pipe 18, the valve 10 having been closed. The pump 20 may also, if desired, be used to assist the opening movement of the door, oil being pumped from the tank 34 through valve 19 and pipe 22 to the left-hand side of the piston 8. The air pressure in the tank 12 may be increased if necessary by a manually operated compressor 28 or from a motor driven compressor (not shown) through a pipe 27.