Patent GB-190414035-A (GB)
Title: Improvements in or relating to Pumps.
Inventor: DAVIS ALFRED EDWIN
Filed: 1904-06-21
Granted: 1905-06-15
Abstract: 14,035. Davis, A. B. June 21. Hydraulically-actuated pumps; flexible-diaphragm pumps; vacuum, preventing.-Consists in placing a flexible vibrating diaphragm in a chamber connected to the barrel of a pump used for pumping gritty or corrosive liquids, for the purpose of separating such liquids from the wearing parts of the pumps. Means are also provided for allowing the clean water which is used in the pump barrel to overflow in event of excessive pressure, or additional water to enter in the event of leakage. Fig. 1 shows a plan, and Fig. 2 a sectional view on the line x-x, of one form of pump with the diaphragms K fitted in chambers B<1> connected with the pump barrel a and the main suction and d, livery pipes a<5>, a<3>. The diaphragms K, which may be made of leather, textile fabric, or thin corrugated metal, are placed between concave perforated plates which are secured between the two parts of the chambers B<1>. Ports a<8> are formed in the cylinder a and lead to supplementary spring loaded suction and delivery valves for keeping the amount of clean water in the barrel constant. The supplementary valves are loaded to greater pressure than the ordinary working pressure of the pump, or an additional adjustable valve or its equivalent is used between the suction valve and the clean-water supply, so that a certain fixed small quantity of water is drawn into the barrel at each stroke. As an alternative arrangement, two ports provided with delivery valves are arranged one at each end of the barrel, and a third port provided with a suction valve is arranged in the barrel between the other two ports. The porta a<8> may be arranged on the pipes connecting the cylinder and diaphragm, and, instead of a single port, two separate ports provided with separate valves may be provided. In the application to an ordinary pump, the existing suction and delivery valves are utilized as the supply and relief mechanism for the clean water. In this arrangement, separate valves are used for the dirty or corrosive water. The lenticular space between the perforated concave plates in which the diaphragm works is equal in capacity to the volume displaced by the pump piston. Fig. 10 shows a modification in which the outer portion of the diaphragm K is held between the parts of the diaphragm chamber B<1> and the central portion between rigid discs L, L<1>. To these discs is connected a guide-rod N working in a fixed tube 0 and operating the pivoted levers T, Z, connected to the relief and supply valves Q, R, respectively. The diaphragm is arranged so that in normal working the levers are not moved, but, on excessive movement of the diaphragm due to an excess or deficiency of clean water, the projection P on the rod N actuates the valve levers. Valves or other means may be provided for allowing the escape of air from the diaphragm chamber. In the modification shown in Fig. 12, the diaphragm chamber is formed of two semicylindrical parts D<3>, D<4>, between the flanges of which the diaphragm K is held, while, in the modification shown in Fig. 14, the vibrating diaphragm is arranged in a pipe D<6>.