GB1488082A - Concrete mixers - Google Patents

Abstract

1488082 Concrete mixers G HUDELMAIER 4 Jan 1975 335/75 Heading B1C In a concrete mixer for use on a concrete mixing vehicle and comprising a rotary mixing drum 1 which has its axis inclined upwardly towards a filling and emptying opening 2 thereof, is conically tapered towards said opening, comprises on its inner surface helical blades 12 for drawing in or forcing out concrete depending on drum rotational direction, and is rotatably supported at its base 3 on a vehicle-supported underframe 4 by way of a shaft 7 fast with the base, there is provided a rotary mixing tool 18 which is disposed within the drum, extends from the drum base up to a maximum of one half (and preferably between one quarter and one third) of the drum length, and is mounted on a further shaft 21 coaxially disposed within the shaft 7 and rotatable relative to the drum by means disposed outside the drum. As shown, drum I is supported on a stand 6 by way of a girth bearing ring 5 and on a stand 10 by way of the shaft 7, a bearing sleeve 8 and a pin 9. The bearing sleeve 8 also supports a water tank 11. The drum is rotated by a fluid motor 15 carrying a pinion 14 meshing a drum-mounted internal gear ring 13. The motor 15 is energised by a frame-mounted pump via flexible pipes (not shown) and is carried by a torque arm 16 pivotally mounted on the shaft 7 and retained by a strut 17. The mixing tool 18 comprises two sets of arms 19 fast with the shaft 21 and carrying blades 20 disposed close to the helical blades 12. The shaft 21 is driven by a motor 22, e.g. fluid, by way of a reducing gearing 23. The drum and mixing tool rotations are of opposite direction. The drum need only rotate slowly and from time to time may be stationary. In Figs. 4-6 (not shown), the shaft 7 is rotatably supported by the shaft 21 which in turn is rotatably supported by the bearing sleeve 8. One torque-arm-mounted fluid motor 15 rotates both the drum and the shaft 21, in opposite directions, the internal gear ring 13 driving a gear (25), fast with the shaft 21, by way of an idler (24). In Figs. 7. 8 (not shown), the shaft 7 is mounted in an angular contact bearing (8") supported on the stand 10, and the shafts 7, 21 are driven by torque-arm-mounted fluid motors (28). (27) by way of reducing gearing (29), (30). In further alternative embodiments, the blades 20 may be replaced by helical, preferably discontinuous, members, and the rotary drives may be effected by frame-mounted motors acting through flexible shafts.