444,845. Flexible-chamber pumps. MULLER, F., 170, Lainzerstrasse, Vienna. March 6, 1935, No. 7086. Convention date, March 6, 1934. [Class 102 (i)] In apparatus for pumping liquids having mineral, vegetable, &c. admixtures, as e.g. scavenging sludge in deep borings, scavenging refuse in mining, sewage, mortar, concrete, &c., the liquid is sucked into, and expelled from, a container by the pulsations of a displacer in the form of a closed hollow body with flexible walls, auxiliary liquid being alternately supplied to, and withdrawn from, the displacer by means of an auxiliary pump. The volumetric capacity of the displacer is greater than the volumetric output of the auxiliary pump for a single stroke or revolution as the case may be, so that a single complete operation of the main pump corresponds to a number of strokes or revolutions of the auxiliary pump ; the distributing mechanism for the auxiliary actuating fluid and the suction and delivery valves of the main pump, which work in the contaminated liquid, are thus operated at infrequent intervals whereby the life of these parts is lengthened. In one arrangement, Fig. 1, two rigid containers 7, 15, provided with displacers 6, 11 respectively, communicate through inlet valves 18, 30 with a suction strainer 17 in the sump 16, and through outlet valves 8, 31 with the delivery pipe 10 provided with an air vessel 9 ; the auxiliary pump 1 withdraws liquid from the displacer 11 through pipe 12, four-way cock 4, pipe 13 and inlet valve 14, and delivers it into the displacer 6 through outlet valve 2, pipe 3, the cock 4 and pipe 5. The container 15 is thus filled with liquid from the sump 16, and the contents of the container 7 are discharged into the pipe 10 ; on operation of the cock 4 either by hand or automatically as described below, the action is reversed, and a continuous flow of contaminated liquid results. The valves 8, 18, 30, 31 may be replaced by a distributing valve such as the cock 4, and may be connected therewith so as to be simultaneously actuated. On starting, the system is filled with auxiliary liquid through a cup 20. The pipe 13 communicates with a reservoir 29 through a valve 28 which is normally closed by a spring; a member 26 is positioned on the delivery side of the pump 1 and should delivery stop owing to leakage losses, the member 25 carrying the flap 26 is moved upwardly by a spring 23 and through a rod 27 opens the valve 28, so that liquid enters the circuit from the reservoir 29 to replenish the losses. The lower end of the displacer, Fig. 3, may carry a weight 55 which prevents floating of the displacer owing to the auxiliary liquid being lighter than the main liquid ; a safety valve 54 allows the contents of the displacer to escape when the pressure therein becomes too great. The weight 55 is carried by a tube 51 telescoping within the supply tube 52. In operation the displacers need not be filled to capacity with auxiliary liquid ; when a single displacer is used, if the volume of auxiliary liquid is less than the maximum capacity of the displacer and associated pipes, bursting cannot take place. The displacer may be of leather, indiarubber or any suitable waterproof material and may comprise a number of small displacers. In a modification, Fig. 4, the pressure container comprises a tube 66 with end caps 67, 68 secured by tension rods 69, 71, is filled through cup 86 and is provided with a safety valve 88. The displacer 79 is filled through a perforated tube 82 provided with a safety valve 78. When the displacer is filled with auxiliary liquid, a float 75 rises to the top of a chamber 72 and when the displacer has been almost emptied, the float 75 drops suddenly, striking a lever 84 to reverse the distributing valve for the auxiliary liquid. The distributer may comprise, Figs. 8, 9, valves 95, 96 connected so as to act oppositely, and valves 97, 98 similarly connected. The valve pairs are actuated by electromagnets 109, 110 respectively, against the action of springs 108 to effect the desired distribution of liquid. The switching of the electromagnets is effected by movements of the float 75, Fig. 4. Pressure containers as shown in Fig. 4 may be mounted in pairs in an inclined position on a transportable frame. The pressure container may comprise, Fig. 15, a number of tubes 135, 136, 137 connected by pipes 143 ; a continuous perforated tube 140 runs through the tubes 135, 136, 137 being supported therein by perforated discs 141. A number of displacers 142 are mounted on the tube 140. The distributing valve for the auxiliary liquid may be reversed automatically after a predetermined number of strokes or revolutions of the auxiliary pump by the mechanism shown in Figs. 18, 19, 20. A member 151 is oscillated about a shaft 153 by a rod 152 connected to a reciprocating part of an auxiliary pump, or to a crank disc mounted on the shaft of a centrifugal pump. Pawls 149 engage through slots in a casing 160 with toothed wheels 154, 155 fast on the shaft 153 which is thus rotated in a counter-clockwise manner, reverse rotation being prevented by a detent 158. The rotation of the shaft 153 is transmitted through a pinion 172 to a gear wheel 173 carrying pawls 174, 175 connected by links 176, 177 to discs 178, 179 fast on the shaft 162. The pawl 175, Fig. 20, engages a nose 180 on the disc 178 to rotate the disc and shaft 162 in a clockwise manner, thus raising to its top position a weight 148 mounted on an arm fast on the shaft 162. The weight 148 then falls to its lowest position, Fig. 22, rotating the shaft 162 through 180‹ ; a tappet 165 on the shaft 162 then engages a nose 164 on a gear wheel 163 loosely-mounted on the shaft 162, rotating the gear wheel 163 through 180‹ ; the wheel 163 engages in a toothed segment 166 fast on the shaft 167 which is thus rotated through 90‹ and rotates the plug 147 of the distributing-valve 146. The rotation of the gear wheel 163 is also transmitted through a toothed segment 161 to the casing 160 ; the pawls 149 and detent 158 are thus placed out of engagement with the gear wheels 154, 155 and the pawls 150 and detent 159 come into operation to effect rotation of the shaft 153 in a clockwise direction. As shown in Fig. 22, the pawl 175 is now out of action, and the pawl 174 engages the nose 181 on the disc 179 to raise the pendulum weight 148 to its top position in a counterclockwise direction. The whole cycle of operations is then repeated. The mechanism may also actuate distributing valves for the contaminated liquid. In a further modification, the actuation of the distributing valve may be effected by appliances actuated by the stoppage of flow of auxiliary liquid as described with reference to Fig. 1 for making up leakage losses in the auxiliary liquid circuit.