GB435328A - Improvements relating to plansifters - Google Patents

Abstract

435,328. Sifting-apparatus. SPEIGHT, J., Alberta, Beech Road West, Felixstowe, and SIMON, Ltd., H., Bird Hall Lane, Cheadle Heath, Cheshire. May 1, 1934, No. 13138. [Class 117] A plansifter comprises a plurality of superposed sieve frames a, Figs. 3 and 4, constituting drawer-like fittings resting in shelves in the main frame and arranged in two or more superposed groups. Each sieve frame is provided with lateral apertures e by which the throughs from each sieve are passed into a collecting duct d which is provided with one or more deflector plates by which the sifted product from an upper group of sieves is directed on to a distributing tray t above the next group. The tailings from each sieve are passed by openings f to the succeeding sieve in the same group, the last sieve in which passes the tailings by an opening g to a collecting duct h at the end of the main frame. When the frame carries a series of superposed groups side by side, as shown in Fig. 3, the tailings are directed by deflectors i in the ducts h to one or more joint discharges j while the throughs are also directed to one or more joint discharge shoots r. The sieves are disposed horizontally and are of a length not more than twenty times the height to which the stock can pile on the sieves so as to enable impellers to be dispensed with. For rigidly securing the sieves in position, each sieve frame, as shown in Fig. 6, comprises two relatively movable wedges m, o by which it is securely clamped on the shelves. In a duplex machine, the sieves in the two parts of the machine are disposed in line in the direction of movement of the material over the sieves.