Improvements in automatic controls for underwater relief valves in the suction pipesof suction dredgers

摘要

929,108. Suction dredgers. M. M. HOFER. Dec. 21, 1961 [Sept. 11, 1961], No. 45866/61. Class 68 (1). [Also in Group XXIX] The control system for the relief valve 6 of the suction pipe 2 of a dredger 1 as disclosed in Specification 815,951 is modified in that three pressure switches of said system are replaced by a differential pressure switch 27. The switch 27 is controlled by the pressure on the discharge side of the suction pump 4, the two valve chambers 33, 34 being connected directly by way of pipe 36 and indirectly by way of pipe 41, buffer chamber 40, and restriction 39 to said control pressure source.