GB244946A - Improvements in sewage screening apparatus - Google Patents

Abstract

244,946. Mills & Co. (Engineers), Ltd., J., and Mills, M. W. Feb. 13, 1925. Strainers comprising grids or gratings.-A screen for sewage is cleaned by a rake which feathers automatically as it is raised and lowered over the screen. The rake t, Fig. 1, is mounted on a shaft e<4> journaled in a frame e sliding in guides c parallel to the screen a. The frame e is raised by a rope i which by intermediate mechanism pulls a chain j<4>, Fig. 2, and turns the shaft e<4> so that the rake t is at right angles to the screen. The intermediate mechanism comprises a three armed lever g pivoted in the slotted head of a bar f<1> sliding in a bracket on the frame e and attached to the chain f<4>. When the screen is to be raised a bar i<1> sliding in a bracket on the frame e and to which the rope i is attached is brought into engagement with a hook g<3> on the lever g bv springs k. When the screen has been raised a bowl h strikes an arm g<2> of the lever g causing the hook g<3> to be released and allow the rake t to fall into a position parallel to the screen while descending. While in the raised position the rake t is cleaned by a rotary rake p turned by gearing and a star wheel p<1>, Fig. 1, struck by a pivoted device r<2> moved by the raising of the rake. The device r<2> is mounted on a slide bar r having a counterweight r<7> and carrying a projecting bracket, r<8>, Fig. 2, adapted to be struck by a pin e' on the rake. The solids from the rake p fall into a trough q, Fig. 1. The rope i passes round pulleys l, m, n and is operated by an air pressure cylinder o.