GB535931A - - Google Patents

Abstract

535,931. Jigs. KRAUT, M. Aug. 16, 1939, No. 23616. Convention date, Sept. 6, 1938. [Class 82 (ii)] In a jig in which the flow of water is caused by raising and lowering the bottom of the hutch and there is an expansible connection between the pan forming the bottom of the hutch and the screen, the pan is reciprocated in the vertical direction with a greater velocity in the downward movement than in the upward movement and the reciprocating means are positioned above the jig bed and operatively connected to the pan. Mounted in a frame 10 adjacent an inlet trough 11 is a screen 13 which is supported between grids 14, 15 the latter being forced down by screws 16, a layer of lead shot 24 and sand 25 filling the compartments formed above the screen and below the grid 15. A second screw 18 similarly mounted and provided with grids 20, 21 is mounted in the other part of the frame 10 near an outlet trough 12. Supported by a section of bellows 28, of expansible material, secured to the lower part of the frame 10, is pan 26 of thin material which can be distorted and provided with an outlet 27. The pan 26 is also supported by a spider 30 mounted on the end of a reciprocating rod 31 which passes through a tube 54 which passes upwardly through the jig and is secured to the lower part of a filter 52 provided with an outlet pipe 53. The rod 31 passes upwardly through a housing 33 supported in a frame 34 mounted in the frame 10 and passes through a tube 40 on which is mounted piston 38 and a flexible disc 37 the latter contacting with the conical end of a cylinder 35 mounted within and attached to circumferentially spaced portions of the housing 33. A water inlet 36 is provided in the housing 33 and cylinder 35 and the tube 40 passes up through a flexible diaphragm 49 and a bearing 43 mounted in the cover 44 of the housing, is surrounded by a spring 46 held in position by a washer 47 and nut 48 and is secured to the end of the rod 31 by a nut 51. In operation the material to be treated and water is fed on to the bed formed on the screen 13 by the trough 11 and water is admitted to the housing 33 by the pipe 36. This causes the upward movement of the piston 38 and so the pan 26 but owing to the disc 37 clinging to the walls of the conical part of the cylinder 35 the upward movement is retarded when the disc 37 can no longer be held by water pressure in contact with the cylinder 35, it opens quickly, the piston 38 rises a little further, and then the sudden drop in pressure causes the piston to be pulled downward rapidly. The slow upward movement and the rapid downward movement of the piston also causes a similar movement of liquid upwardly and downwardly through the bed of the jig. As a result of this movement the heavy particles are forced downwardly on to the screen and the lighter particles which rest are discharged over the trough 12. To assist in this action a bumper in the form of -a rubber ring may be mounted under the pan 26 and round the outlet 27.