Patent GB-191112055-A (GB)
Title: Improvements in Apparatus for Raising or Forcing Liquids and Compressing Gases.
Inventor: HUMPHREY HERBERT ALFRED
Filed: 1911-05-18
Granted: 1912-06-18
Abstract: 12,055. Humphrey, H. A. May 18. [Cognate Application, 12,449/11.] Actuating by gas engines.-Comprises an internal-combustion pump without a fly-wheel, for liquids or gases, wherein suitably heavy masses capable of acquiring the necessary momentum reciprocate so as to store energy at each stroke, which is available to cause or assist the next stroke, and wherein the expanding gases act between and directly upon two or more pistons or their equivalent which constitute a part or the whole of the masses that reciprocate, and between which, by a movement towards each other, the combustible mixture or a constituent thereof is compressed to a desired pressure before ignition. Four-stroke-cycle pump. Fig. 1 shows a fourstroke-cycle pump in which two solid pistons 2, 3 reciprocate in the combustion chamber 1. Assuming that the pistons are close together with a compressed charge between them, the charge is ignited and the pistons are forced apart, driving liquid through the pipes 18, 19 into the delivery pipe 20. When expansion has reached atmospheric pressure, the exhaust valves 21, 22 open and scavenging air enters through the valve 24 to expel part of the burnt products. At the same time the momentum of the liquid in the pipes 18, 19, 20 causes the inlet valves 16, 17 to open and fresh liquid to be drawn into the apparatus. A return flow of liquid then occurs, driving the pistons 10, 11 towards each other and expelling burnt products and air through the valves 21, 22 until the pistons have passed these valves, whereupon a cushion of gas is compressed between the pistons which arrests their motion and effects a second outward movement thereof. The valves 21, 22, 24 are now shut, and a fresh charge of combustible mixture is drawn in through the valve 25, whereupon the pistons return once more under the action of the head of liquid, and the fresh charge is compressed ready for the next explosion. The pistons 2, 3 are made hollow for cooling purposes, and may be of differential form so as to compress air cushions in the spaces 4, 5 to assist the return strokes. The following modifications of this form of apparatus are described. (1) The air cushion spaces 4, 5 may be replaced by separate air cushion cylinders, with pistons mounted in tandem with the pistons 2, 3. (2) The pistons 2, 3 may be connected by link - work to constrain them to move symmetrically. (3) The return movements of the pistons 2, 3 may be assisted by vacuum energy due to the evacuation of the inner ends of the air cushion cylinders produced on the outward stroke. (4) The pistons 2, 3 may work in separate cylinders arranged side by side with a connecting pipe or passage between them at one end. (5) The capacity of the air buffer or cushion may be made regulable either by means of air reservoirs such as 6, 7, 8, 9, Fig. 1, or by suitable by-pass devices, so that the movement of the pistons may be checked to any desired degree, and the proportion of energy for effecting the return stroke derived, respectively, from the delivery head of liquid and from the air cushion, may be varied at will. (6) When used for the propulsion of ships, the pump may be arranged as shown in Fig. 7, so as to produce a balance of forces in all directions. (7) The power stroke of the apparatus may be arranged to draw in liquid or fluid which is delivered on the return stroke. Two-stroke-cycle pump. Fig. 6 shows a twostroke-cycle pump in which the pistons serve the functions of opening and closing ports for the admission and exhaust of the elastic fluids in a manner similar to that of the Oechelhauser gas engine, and in which the inward movements of the pistons are effected solely by the expansion of air cushions so that non-return valves may be fitted in the liquid delivery pipes. During the outward movements of the pistons, combustible gas is compressed in the space 69 and reservoir 63, scavenging air is compressed in the space 70 and reservoir 66, and air cushions are compressed in the spaces 81. As soon as the piston 2 passes the opening of the pipe 59, scavenging air is admitted to the cylinder and burnt products expelled through the exhaust ports which have been uncovered by the piston 3. Upon further movement of the piston 2, the fresh charge is admitted from the pipe 60, whereupon the pistons return under the action of the air cushions and the fresh charge is compressed and ignited. Passages 82, 83 may be formed in the pistons for cooling purposes. The pipe 60 may be replaced by a passage running through the piston. In the form shown, air vessels are fitted outside the suction and delivery valves 16, 17, 75, 76, so as to reduce the inertia of the moving mass of liquid; but these may be dispensed with, and in some cases the inertia of the mass may be sufficient to give a practically continuous flow of liquid. The length of the stroke may be regulated in the form shown in Fig. 6 by having rings of admission and exhaust ports at different positions in the cylinder, with means for closing those not required. Valve gear and control. In both forms of pump the valves may be controlled by cyclical changes of water level, as described in earlier Specifications, or the valves may be mechanically controlled as described in Specification 11,527/11, [Class 102(ii) Water &c., Raising &c.]. The controlling devices described in Specifications 11,818/11 and 13,342/11 may also be applied to regulate the action of the apparatus. Compressing gases. The form of apparatus shown in Fig. 6 may be used for compressing elastic fluids, in which case it may be possible to dispense with air cushions, since the compressed fluid in the working space will act as the equivalent thereof. The form shown in Fig. 1 may be modified for compressing elastic fluids in the manner described in Specification 22,646/07 Multiple - piston apparatus. Three or more pistons may work in cylinders communicating with a common combustion chamber, and may be used for pumping different liquids or elastic fluids simultaneously, or two of them may be used for compressing scavenging air and combustible gas respectively. Two or more combustion chambers may also be combined in one machine to operate together so as to give a constant delivery.