GB795558A - Improvements in reciprocating piston pumps for concrete and drier plastic materials - Google Patents

Abstract

795,558. Reciprocating pumps. WEISNER, B. Nov. 14, 1955, No. 32424/55. Class 102(1). A concrete pump comprises parallel cylinders 43, 55, Fig. 4, in which are reciprocated out-ofphase pistons 45, 51 and which are connected at adjacent ends to a valve chamber which has a hopper inlet 63, Fig. 5, a discharge outlet 39 and a ported body 40 which is oscillated in unison with the pistons 45, 51 so that during the return stroke of piston 51 concrete is drawn from the hopper 63 through a valve body sector 49 into the cylinder 55 from which the piston 45 on its forward stroke forces concrete through a valve body passage 41 into the discharge outlet 39. The pistons are reciprocated by a driven pinion 46 engaging racks 47, 56 and the valve body 40 is rocked by a rack 42 engaged by pinions 58, 59 ; the latter being loose on the shaft 64 of pinion 46 and rocked thereon by abutment of a cam on shaft 64 against a cam of the shaft 62 of pinion 59. In a modification the valve body 17, Fig. 1, is rocked about a vertical axis by means of a link 6 connected by a rod 7 to the piston of a hydraulic cylinder 27 and has two through passages 3, 18 one of which connects the cylinder being discharged to an outlet 16 whilst the other is closed by the valve casing. Concrete is drawn from the hopper through one or other of spaces 10, 10<SP>1</SP> into the cylinder being charged. The out-of-phase pistons 19, 21 are mechanically connected to hydraulic cylinders 24, 23 in a circuit comprising a motor driven pump 26, a reservoir 37 and a distributing valve 30 reversal of which is effected by cams 28, 29 on the rod 7. Reversal of the distributing valve 33 for the valve actuating cylinder 27 is effected by abutment of cams 31, 32 against rollers 38, 39 carried by opposite ends of a valve rod 33<SP>1</SP>. In a modification the valve body 101, Fig. 8, is rocked about a horizontal axis within a cylindrical casing 89 having flat ported end walls 90<SP>1</SP>, 90<SP>11</SP> and comprises an approximately semicircular end plate adjacent the pump cylinders 92, 93 and a circular end plate nearest the outlet 96 ; the plates being connected by bores 103, 104, Fig. 9, which according to the position of the valve body connects the cylinder being discharged to the outlet 96, the other cylinder being open to the hopper 91. In a similar modification the valve body has a single bore. In a still further embodiment similar to that shown in Fig. 1, the concrete is discharged in spray form by compressed air and reversal of the distributing valve for the hydraulic cylinder is effected by a fourth hydraulic cylinder ; reversal of the distributing valve for the hydraulic cylinder for rocking the plug valve being effected mechanically as shown in Fig. 1.