GB487351A - Improvements relating to intermittent driving mechanism especially for filtering or thickening apparatus - Google Patents

Abstract

487,351. Chain, belt, and rope gearing. DURANT, H. T. Feb. 12, 1937, No. 4307, [Class 80 (i)] Consists in intermittent driving mechanism particularly adapted for withdrawing a filter element from and returning it to a, tank of a filter or thickener, in which a continuously moving flexible element, chain, belt, or rope is caused to move an element first in one direction and, after an interval to move it in the reverse direction. A framework 1, Fig. 1, supports shafts of sprocket wheels 2 .. 7 around which passes an endless chain 8. The sprocket wheels 5, 6, of which 6 is mounted on the shaft 10 to be driven, each comprises a central fast sprocket 12, Fig. 4, by the side of which are loose sprockets 11, 13. The chain 8 consists of two parallel runs, Fig. 3, which engage the sprockets 11, 13 and one or more inserts 9 adapted to engage, at intervals, the fast sprocket 12. The sprockets 2, 3, 4, 7 are merely idlers. instead of a chain, a belt or rope with projections or knots may be employed. A countershaft 16 and the shaft 10 of the driven sprockets 5, 6 are connected by a chain 17 on sprockets at the side of 5 and 6, so that when one of these shafts is rotated, the other is also rotated. Assuming the chain &c., which is driven by a motor 15, to be moving in the direction of arrow A, and that the insert 9 is located at a, b, nothing happens until this insert engages the central sprocket of member 5 which is then rotated anticlockwise and this movement is transmitted by the chain 17 to the member 6, so that the filter element 20, on the shaft 10, is withdrawn from the tank 22. When the insert leaves the member 5, an interval of rest occurs, during which the element 20 can be cleaned by rollers 24. When the insert 9 reaches the central sprocket of the member 6 this member is now rotated clockwise, and the member 20 returned to the tank. The actual drive of the members 5, 6 by the insert 9 may be in the same direction, the chain 17 then being crossed, and the driving chain passing around both members 5, 6 in the same direction. The movement of the driven member in one direction may be caused to be different from that in the other by adjusting the are of contact of the chain &c. Further, the drive may be positive for only a part of the movement, the element continuing by its own momentum. The element 20 is connected by means of a manifold valve and flexible piping to a vacuum pump 23. An agitating worm 25 is located in the bottom of the tank. In a modification, a sprocket on the shaft 10, is connected by a chain or belt to a pulley supporting a leaf filter which is moved vertically into and out of the tank, the filter being held at the top of its stroke by a band brake actuated by the insert 9. A battery of filtering units may be actuated by the chain 8. The shaft 10 may, in the above arrangements, be extended laterally in both directions to carry a number of filtering elements 20.