Patent GB-190222610-A (GB)
Title: Improvements in & connected with Fluid Pressure Engines & Pumps.
Inventor: MCCALLUM NEIL
Filed: 1902-10-17
Granted: 1902-12-18
Abstract: 22,610. McCallum, N. Oct. 27. Hydraulically-actuated pumps; steam pumps.- Relates to fluid-pressure engines and liquid &c. pumps. Fig. 1 shows a single-acting engine combined with an air pump. Beneath the pump cylinder 2 is mounted a valve-casing 1, in which slides a piston 11 coupled to a valve 9 of smaller area by a neck 10, such valve sliding within an inner chamber. Just above the inlet port 5 is arranged a belt 6 communicating with the underside of the pump piston 3 by one or more ducts, and with the port 5 by an opening 8 adapted to be closed by the valve 9. A tube 12, provided with port openings 15, passes through the valve and piston, and is arranged to slide relatively to the same, suitable packing being interposed between the parts. his tube is open at the bottom and extends below the piston 11, and at the top it is coupled to a rod 13 extending within a recess in the piston 3. When the piston is in motion, the ends of this recess come against a nut 14 on this rod and operate the tube 12. When the piston 3 and the tube 12 are in the lowest position, fluid passes through openings in the neck 10 and the passages 15 in the tube to the space underneath the piston and forces the same upwards, thereby admitting fluid through the opening 8 to the bottom of the piston 3. This piston, as it rises, carries the tube 12 upwards until the passages 15 are above the valve 9 and in communication with the exhaust port 19. When this occurs, the fluid from beneath the piston 11 passes away to the exhaust, and the piston is forced downwards until the valve 9 is below the opening 8, in which position the space beneath the piston 3 is open to the exhaust. Upon the escape of the pressure fluid, the piston 3 falls and returns the tube 12 to its lowest position, after which the cycle is repeated. Fig. 2 shows a double-acting engine suitable for application to a double-acting pump for beer and other liquids. Within the valve-casting 20 are arranged two pistons 21, 22 and a valve 23 of of smaller area, the three parts being connected by a neck 24 provided with openings to open up communication with the space beneath the piston 21 through the tube 25, which is provided with ports or passages 43, 44. The passages 36, 37 leading to the opposite sides of the piston 35 are alternately connected to the supply port 26 and exhaust port 31 through passages 33, 32. The tube 25 is operated, by the piston 35, by means of a rod 48 secured to the tube and taking into a bush 47 in the piston, the rod being provided with a nut to engage the ends of the bush when the piston is in motion. The bush may be extended as a solid shaft to form the piston-rod of the pump. The movement of the tube 25 brings the space beneath the piston 21 alternately into communication with the supply and exhaust ports, thereby ensuring the working of the valve. The movement of the piston 22 and valve 23 bring each of the openings 32, 33 alternately into communication with the supply and exhaust ports, whereby the working fluid is alternately supplied and exhausted from each side of the piston 35. The lower end of the tube 12 works in a pocket 45 connected to the exhaust port, so that the tube cannot be accidentally operated by the pressure fluid.