GB973063A - Improvements in or relating to weighing and discharge apparatus - Google Patents

Abstract

973,063. Weighing apparatus. E. L. CLEMENTS. Dec. 31, 1962, No. 49163/62. Heading G1W. [Also in Division B1] A mixing system has in combination, means 29 for delivering a predetermined weight of one component e.g. a mineral filler or aggregates such as stone or lime dust or cement, a mixer 31 comprising an open-topped container 33 and a rotary mixing element 32 disposed lengthwise of the container to provide a mixing space 35, Fig. 7, along the container between the side wall and the peripheral radial extent 32a, of the mixing element, and means 34 for accumulating a predetermined weight of a second component e.g. asphalt, water, or cement, the means 34 being disposed to dump the material contained therein through the top of the container 33 along the length of the mixing space 35, the material being dumped in a direction common to that of movement of the element 32 adjacent the mixing space. Fig. 1 shows an asphalt plant in which aggregates from a hopper 10 are conveyed to a drier 12, which is of the rotary cylindrical type with interior lighting flights, and is fixed by an oil burner 13, the aggregate then being fed to a vibratory screen 18 to grade the aggregates into compartments 19, 21, 22, 23 in a bin 24. Mineral filler is fed to a bin 27, the filler and aggregates being fed to the means 29, which is in the form of a weighing hopper adapted to register an exact predetermined weight of each size of aggregate from the bin 24 together with filler from the bin 27. When these weights have been attained the feed is stopped and the weighed mass is discharged to the mixer 31 via a hood 53, Fig. 2, covering the means 34, the hood serving to distribute the aggregates and filler to the mixing spaces 35. Simultaneously hot asphalt from a tank 42 is fed to the means 34 which takes the form of one or more trough-like members mounted for rotation on shafts 37. The asphalt is fed through branches 45 of a supply conduit 44 and the trough-like members are supported by a framework 38 attached by lever arms 39 to a weighing apparatus. When the predetermined weight of asphalt has been attained, the weighing apparatus serves to stop the feed of asphalt and to operate an air ram 50 to move a toothed rack 51 against the action of a spring 52 to rotate pinions 41 on the shaft 37 so that the asphalt is dumped into the mixer 31 along the length of the mixing spaces 35 as shown in Fig. 7. The mixer element or elements 32 has paddles mounted for rotation therewith for speedy mixing. The trough-like members may have integral deflectors 79, Fig. 2, at their ends to direct some of the asphalt from the ends of the mixer. The branches 45 may have flap valves as shown in Fig. 5 to prevent dripping of the asphalt, and these valves and the supply of asphalt may be controlled so as no delivery takes place unless the trough-like members are suitably positioned. Different arrangements of single and double trough-like members and mixing elements are described in the Specification.