GB332428A - Improvements in concrete-mixing machines - Google Patents

Abstract

332,428. Dunlop, S., (Koehring Co.). Aug. 13, 1929. Rotary mixers.-A concrete mixer of the conical, tilting drum type is provided with automatic means for operating the charging skip, supplying a measured quantity of water, and tilting the drum to its charging and discharging positions at the beginning and end of the mixing operation. For this purpose a shaft 17, Fig. 8, driven from the prime mover, drives a screwed shaft 58 through a clutch 61 and direct and reverse trains of gearing 56, 60, and 49, 62, 59; the gears 49 and 50 are on a, sleeve 51 clutched to the shaft 17 by a hand-operated clutch 52. The screwed shaft 58 operates a slider 72 having a sleeve member 76 surrounding a rod 70 and provided with a projection 87 engaging a catch 85 on a second rod 80 connected with a clutch 45 operating the winding-gear for the charging skip and with a brake 93. As the slider 72 moves to the left, a projection 77 thereon engages a fork 90 which, through a rod 91 and lever connections, operates a three-way valve 92 connecting the measuring tank with the mixing drum and main alternately. The projection 77 then engages an arm 82 operating the link 80 which throws the clutch 45 into operation to raise the charging skip. The sleeve 76 then engages a spring-mounted collar 78 thus moving the rod 70 and operating, through a bell-crank 69, link 68, and snap-over lever 66, a slider 63 controlling the clutch 61; by these means, the rotation of the shaft 58 is reversed and the slider moves to the right. The projection 87 thereon engages the catch 85 and moves the rod 80 to disengage the winch clutch 45 and apply the brake 93 controlling the lowering movement of the changing skip; the catch 85 is thrown out of engagement by a fixed pin 88. An adjustable stop 75 on the slider then engages a second spring-mounted collar 79 and moves the rod 70 thus effecting a second actuation of the clutch 61 to reverse the rotation of the shaft 58; the movement of the slider 63 operates a striker 94 which sounds a gong indicating the end of the mixing operation. The movements of the rod 70 operate an arm 35 on a shaft 30 which, as shown in Fig. 5, operates a pair of yokes 29 controlling clutches on a pair of bevel gears on a constantlydriven shaft and in mesh with a bevel on a worm shaft 22 which tilts the yoke F in which the mixing-drum is mounted. The clutches are automaticall thrown out of gear by the engagement of cams 32 in the worm wheel 20 with arms 31 on the control shaft 30 at the ends of the tilting movements of the mixing-drum.