GB728486A - Sand handling apparatus for use in foundries - Google Patents

Abstract

728,486. Endless conveyers. PETTIBONE MULLIKEN CORPORATION. June 22, 1953, No. 17259/53. Class 78 (1). [Also in Groups II and XXII] A portable foundry sand handling and conditioning apparatus comprises a wheeled frame structure, sand accumulating and elevating means mounted on the front end thereof, a rotary power-driven magnetic separatormounted over the rear end of the frame to separate metallic scrap from sand delivered thereto, and a self-contained sand screening, aerating and discharging unit disposed beneath said separator and comprising a gyratory screen, a bladeequipped motor beneath the screen, a discharge spout, and a driving motor for the screen and rotor, the unit being mounted so that it may be rotated about a vertical axis to position the discharge spout so that it faces rearwards or to either side of the frame structure. The frame structure 25 is movable on a rear castor assembly 41 and two wheels 42, the latter being chaindriven from an electric motor 59, Figs. 1, 2, 7, through a variable speed reduction unit 60 and clutches 69, 97, the clutches being actuated by levers 76, 104 and each incorporating a band brake applied by the declutching movement of the associated lever so that either one or both of the wheels 42 may be driven or braked. A pivotably mounted hollow column 28 extends upwardly and rearwardly from the front of the frame structure and supports and houses the screw conveyer 30, bucket elevator 31 and magnetic separator 32. The column is mounted on a horizontal shaft 140, Fig. 8, about which it is tiltable by a hand wheel 156 and gearing comprising a worm and worm-wheel 158, 159. The lower end of the column carries a plough 143 with adjustable wear plates 146, 149, hinged to side beams 35 of the structure by hinges 152 so that it may be swung upwards and downwards by turnbuckles 153. The plough houses the screw conveyer 30 comprising spiral sections 173 on a shaft 172 which feed towards the central portion, sand confined within the plough. The bucket elevator 31 which elevates the sand at the central portion of the conveyer 30 and discharges into the discharge shoot formed at the upper end of the column 28, comprises buckets 184 carried on an endless chain 183 moving over sprockets 181, 182. The sprocket 182 is secured to a shaft 185, Fig. 1, which is journalled in bearings 187 which are adjustably positioned in guide frames 188 by adjusting screws 189. The sand passes through the discharge shoot over the magnetic separator 32, comprising a rotary drum and a magnet 191. Metallic scrap is carried round by the drum until it leaves the field of the magnet when it drops into a discharge shoot 198, thence into a receptacle 200. The screw conveyer, bucket elevator and separator are driven through chain gearing and a speed reduction unit 204 by a motor 203. The screening, aerating and discharging unit 34, Figs. 16, 19, is located at the rear end of the frame structure to receive sand from the discharge shoot 138, and comprises a gyratory screen 221, a hopper 222, a bladed rotor 223, a housing 224 with a wear-resisting liner and a discharge spout 225, the unit being mounted on a turntable 227 supported on bearings 268 so that it may be turned about a vertical axis through an arc of about 240 degrees. Friction plates 272, 273 actuated through a toggle linkage operated by a pedal 281 lock the turntable in position. A motor 226 drives the rotor 223, and also gyrates the screen and hopper, which are mounted on a bearing eccentric to the motor shaft. Foreign objects removed from the sand by the screen travel downwards across the screen, over a lip into a trough 293 from which they may be removed by way of discharge openings 297.