GB642844A - Improvements in and relating to vibrating screens - Google Patents

Abstract

642,844. Sifting-apparatus. TAYLOR, E. March 22, 1948, No. 8378. [Class 117] In an inclined vibrating screen for use in coal, gravel, stone and similar screening plants and having upper and lower decks 2, 3 supported on opposite sides of the intermediate pivots 10 of arms 7 rocked by eccentric rods 16 driven by a rotating shaft 12 having flywheels 22 thereon, means are provided for adjusting the stroke of the screen and the angle of the driving arms 7. As shown, the eccentric rods 16 are adjustable as regards their lengths so as to adjust the inclination of the driving arms 7 and the adjustable stroke of the screen is obtained by adjusting the point of connection of the rod 16 along an extension 18 of the driving arm 7 for which purpose a series of holes 19 is provided. through one of which the connecting pin 17 is passed. The lower portion of the arms 7 below their pivots 10 may be longer than the upper portion to help balance the screen and compensate for the greater load on the upper screen deck and balance weights such as 20 may be added to the pivoted arms or the screen decks. The driving shaft 12 has flywheels 22 at either end and these wheels may be fitted with adjustable weights to counteract any unbalance of the shaft. The screening mesh may be tensioned to the sides of the deck by bolts 23 (Fig. 4) passing through clamping plate 24 to clamp the plate against the action of helical springs 26 and by bolts 27a with eccentric washers 27 bearing against the edge of clamping plate 24 to allow of different thickness of mesh.