Patent GB-425146-A (GB)
Title: System and apparatus for pumping hazardous liquids
IPC: B67D7/32
Filed: 1934-05-11
Abstract: 425,146. Hydraulic transmission of power. UNGAR, G. A., 1775, Broadway, New York, U.S.A. May 11, 1934, No. 14276. Convention date, May 11, 1933. [Class 69 (ii)] [See also Group XXVI] In plant for dispensing petrol &c. a unit 36, Fig. 4, submerged in each underground tank 30, comprises a rotary motor driving a rotary pump, the motor being supplied with driving liquid by a distant pump 92 driven by an electric motor 93. A gear-wheel motor 46, Fig. 2, may be employed driving a gear-wheel pump 50, or a centrifugal or other rotary pump may be employed. Each motor is supplied by a pipe 85 and passage 48 and exhausts by a passage 49 and pipe 86. The pump draws through a valve 52 and discharges by a passage 53 and pipe 87 to the meter 31 and hose 34. The pump 92 circulates liquid through pipes 95, 96, 107 back to the suction tank 94. Each stand has a control valve 105, 1051 and when the control valve is closed the liquid passes to the corresponding motor through the pipes 85, 86. The valves 106, 105<1> may be operated by connections 102 from the hose pipes 34. The motor 93 is controlled by a hand-operated switch 100 and is started and stopped by an automatic switch 118. For this purpose the valve 105 or 105<1> in the operative position establishes a connection by a passage 113 from a pressure chamber 110, which has previously been charged through a passage 111 and valve 112. The liquid from the chamber 110 passes by the pipe 95 and a pipe 115 to a plunger 116, which closes the switch 118. If the pressure in the chamber 110 is insufficient to close the switch 118 a hand-lever 121 is operated to close a switch 120, the lever at the same time closing a valve 109, which controls the passage from the pipe 107 to the tank 94, thus enabling the pressure to build up rapidly. The plunger 116 then rises and closes the switch 118 and at the same time moves the lever 121 to open the switch 120. The return of the valve 109 is checked by the throttling action of a needle valve 126 on the liquid. When the units 36 are inoperative the fall in pressure causes the plunger 116 to open the switch 118. In a modification, Figs. 6 and 8, the chambers 110 are dispensed with and the lever 156, which operates the control valve 99 or 991, carries a hinged cam 157, which depresses the spindle 154 of a diaphragm 153 in a casing 152, 152<1> thus causing a surge of liquid through a pipe 146 to a diaphragm 145. The spindle of the latter operates the motor switch 140. When the cam 157 clears the spindle 154 the diaphragm 153 returns slowly owing to the throttling action of a needle valve 160. The diaphragm 145 also rises, but the switch 140 is maintained closed by the action of the pressure on a plunger 142. As shown in Fig. 17, each unit 36 may be withdrawn from its tank 30 through a tubular casing 79 and a chamber 89. The unit is carried by its pipes 74, 75, 76, which are secured to a head 83 attached by studs 88 to the base of the chamber 89. The head 83 and the base are formed with passages 851, 861, 871, which establish communication with the pipes 85, 86, 87. The operation of the control valves 105 by the hose 34 may be effected in the manner shown in Fig. 24, in which the hose passes round a pulley 171 sliding vertically on rails 177, and round a pulley 172 carried by a lever 174, pivoted at 175. When the hose is withdrawn the pulley 172 moves to the left and the pulley 171 rises and its spindle strikes a lever 180, which is linked to the valve 105. Fusible plugs may be provided in the chambers 110, Fig. 4, and elsewhere to effect release of pressure in case of fire. The Specification as open to inspection under Sect. 91 describes also a modification in which the motor driving the master pump is not controlled from the dispensing stands. This subject-matter does not appear in the Specification as accepted.