Patent GB-814117-A (GB)
Title: Improvements relating to material screening apparatus
Inventor: SYMONS LOREN GLENN
IPC: B07B1/48
Filed: 1957-04-25
Abstract: 814,117. Sifting apparatus. NORDBERG MANUFACTURING CO. April 25, 1957, No. 13228/57. Class 117. A vibratory screen deck consists of a number of flexible screen sections arranged in line longitudinally of the deck the screening medium of each section is secured at its ends to transverse supports extending right across the deck and is maintained in an arched condition by transversely extending intermediate means provided between the supports, and at least one of the supports or intermediate means is mounted for limited movement in a direction generally at right angles to the general plane of the screen deck and can be fixed in any desired position along that path of movement so that different degrees of arching of the screen section are obtainable. In Fig. 1 the screen deck comprises sections A1- A4 each consisting of parallel rods R spaced transversely across the deck and resiliently clamped at their ends between supports. Adjustable intermediate supports R1-R4 cause flexing of the rods upwards to the desired degree. The screen deck is attached to an inner housing 34 resiliently mounted within a fixed outer housing 10 and vibrated by an unbalanced rotor mechanism 42. One end of the housing 34 is supported by a resilient element 32 and the other end by two resiliently mounted rods 36. The clamping means C1-C3 are identical and each consists of a transverse channel 90, Fig. 3, extending between the side walls of the inner housing and secured thereto by plates 86. A number of blocks 94 are positioned in the channel, and transverse plates 96 with channels 98 containing rubber strip are attached to them. The screen rods are clamped between these strips and further strips 114 on a clamping bar 106 urged downwardly by clamping bolts 104. Bolt head guards 110 are secured to the clamping mechanism. At the lower end of the deck the clamping arrangement includes a plate 140, Fig. 1, on a transverse angle 138 extending between the walls of the inner housing, a clamping plate 146 and bolts 148. A rubber support strip 144 is received in a channel on the plate 140 and a further rubber strip is arranged on the underside of the plate 146. At -the feed end of the deck the clamping mechanism is a separate and removable unit, and includes a transverse plate 64, Fig. 3, which pivotally rests on the upper edge of an angle 57 extending between the side walls of the inner housing. The plate 64 is slotted along its length so as to extend through a fixed slotted transverse angle member 58 secured to fixed members 50 and 48. A channel 74 contains rubber strip and a further strip is attached to the member 50 so that when the spaced clamping bolts 70 are bolted down the plate 64 is pivoted about the angle 57 to clamp the ends of the screen rods. The bolts are protected by a rubber mat 82 and wedges 84. Each flexing mechanism R1-R4 includes two transverse angle supports 116, Figs. 1 and 3 extending between brackets 126, Fig. 5, each support carrying a channel 122 for rubber strip on which the rods bear. The brackets are connected by cap screws 128 to brackets 132 bolted to the sides of the inner vibratory housing. The screws 128 threadably engage bosses 130 and rotation of the screws effects the raising or lowering of the supports 116. In Figs. 13 and 14 iinstead of rods, small wires 200 extend longitudinally and have transversely disposed groups of interwoven wires 202, each group comprising outside wires 204 and inner wires 206. A part 208 of each screen section hooks over its end supports, Fig. 13. The resilient clamping arrangement at the feed end consists of fixed transverse, angles 210 providing a support for a clamping plate 216 having orifices for clamping bolts 219 which engage a fixed block 224. Plate 216 also rests on a block 212 and clamps the end of the screen section between rubber strips. In the embodiment of Fig. 17, the inner vibratory housing supporting the screen deck is resiliently mounted at the feed end on a flexible support 434, and the housing walls at the other end are supported by springs 440. Each scren section 603, 604 and 605 comprises transversely spaced parallel rods extending over two intermediate fixed supports 452, each support comprising -transverse members 460, Fig. 18 carrying channels 462 for the reception of rubber strip. The latter is slotted to receive the rods. The feed end of the upper section is clamped between rubber strip on transverse plates 442 and a bracket 444. At the other end of the deck an angle 518 and a channel 522 clamp the lower end of the lower section with the interposition of rubber strips. Side brackets 514 carrying the angle 518 are adjustable on the housing walls. The clamping mechanisms 608, 609 are similar, and include fixed transverse beams 494, 496, Fig. 18, carrying rubber strip supporting channels 492 on to which the rod ends are clamped by a vertically adjustable clamping bar 470. Rubber strip is secured to the underside of the bar which is secured to plates 472, Fig. 19, extending through openings 474 in the side walls of the housing. Cap screws 478 engage extensions of the plates 472 and are screwed to brackets 482 bolted to the housing walls; rotation of the screws raises or lowers the clamping bar. Each opening 474 is closed by an adjustable plate 502 positioned on the inside of the wall and clamped in the desired position by strips 504, a threaded rod 510 and a nut. The lower edge of the plate 502 is slotted to embrace the clamping bar.