Patent GB-248039-A (GB)
Title: Improvements in or relating to pumps
IPC: F04B1/00
Filed: 1924-11-20
Abstract: 248,039. Lunge, E., and Courtaulds, Ltd. Nov. 20, 1924. Multiple-delivery piston pumps; pumps for viscous liquids; valves, arrangement of; pipes; mountings; locking and releasing devices; regulating delivery by by-passes.-In apparatus for delivering liquid at a constant rate in which two reciprocating pumps ha.ve each a delivery stroke including a period of delivery at a uniform rate towards a common outlet, these periods successively operlapping, a third pump accommodates during the overlapping periods all flow towards the outlet that is in excess of the desired amount, the piston of the third pump moving at all times at the same rate as that of one of the delivery pumps but in the opposite sense. The apparatus is applicable to the supply of viscose to a spinning- nozzle for the manufacture of artificial silk. In one form, Figs. 1 and 2, pump cylinders 12, 13, 14 communicate with a supply passage 10 by means of transverse passages 11, 15, 28 provided with valves 16, 18 having through passages 17, 19, 29, and the cylinder 14 has an outlet port 20 leading to a spinning-nozzle. Pump pistons 21, 23 in the cylinders 12, 14 each move at a uniform rate during the greater part of their delivery strokes and the return strokes are effected quickly; the third piston 22 moves always at the same rate as the piston 23 but in the opposite direction. The pistons are moved by pegs 42 on rods 39 - - 41 sliding in grooves in a base 30. The valves 16, 18 have arms 44, 45 connected by a link 43, the arm 45 being also connected by a link 47 to a peg 48 on a sliding rod 49 for actuating the valves. In action, when the piston 23 begins its uniform delivery stroke, the valve 18 is closed and the valve 17 is open; the piston 22 is moving outwards at a uniform rate and the piston 21 has begun its rapid outward movement, liquid being drawn into both cylinders 12, 13 from the supply passage 10. At the end of its outward stroke, the piston 21 reverses and begins its slow uniform movement inwards at the same rate as the outward movement of the piston 22. At this point, the valve 16 closes and the valve 18 opens; the piston 23 reaches the end of its uniform delivery stroke, stops, and returns quickly, the piston 22 similarly stopping and moving quickly inwards. During this stage, the liquid in the pump 13 is transferred to the pump 14, the pump 12 serving to maintain the uniform supply of liquid to the outlet. When the pistons 22, 23 stop and commence their slow return, the valve 18 is closed and the valve 17 opened, and the cycle is repeated. A number of pump units such as described may be arranged end to end, the passage 10 in each unit being in alignment with those of adjacent units and the sliding rods 39, 40, 41, 49 actuating the pistons and valves of all the units. These rods may be actuated by a screw device. Any unit of the assemblage of pumps may be put out of action by disconnecting the link between the valve arm 45 and the corresponding peg 48 on the rod 49. Each unit may have a passage 27 forming part of a return-flow passage used in the manner described in Specification 248,046. The units are mounted on a base-plate 30, a recess 32 in each unit engaging a lug 33 on the base 30, which has at the other side a flange 34 with a lip 35 engaging the pump unit. The unit is secured to the base by a bolt 36 having an eccentric head 37 engaging a recess 38 in the base. When starting the pumps, the pistons are retained at the inner ends of their strokes by a plate notched to fit over grooves 51 at the ends' of the pistons and over bolts 53a on the pump body. The valve 16 is then opened and the liquid drives out air from the passages 11, 15, 28. In a modification, Fig. 7, the three cylinders 54, 55, 56 are arranged for control by a single rotary valve 57. Supply and return passages 53, 64 are provided and a rotatable by-pass valve 62 enables the cylinder 56 to be connected to the delivery port 63 or to the return passage 64. In another form, the pump cylinders are arranged in a vertical plane above the supply passage, and each cylinder is constituted by the annular passage formed by two pistons of different diameter. The plungers of each unit abut against and are driven by those of adjacent units, as described in Specification 248,041. In a further form, Fig. 10, in which the pump cylinders 82, 83, 84 are arranged in a vertical plane above the supply passage 85, a single rotatable valve 87 has a chamber 88 with downward and upward extensions 89, 90 connecting the cylinders 82, 83 alternately with the supply passage 85 and with the pump cylinder 84. In another form, Fig. 13, slide valves work in longitudinal passages parellel to the cylinders 117, 118, 119 and the supply and return passages 115, 116, and the valves of different units may be in abutment and are actuated by a device at one end of the assemblage of units. The passages are closed where necessary by plugs 137 held in place by a bracket 139 on the supporting bench. The pistons are actuated by means of a rod under the pump body carrying a member which engages each pair of pistons.