GB231386A - Grinding mills - Google Patents

Abstract

231,386. Sedberry, J. B. Sept. 18, 1924. Impact pulverizers.-In a grinding- mill with pivoted hammers carried by a rotatable hammer-support, each hammer consists of a single piece of material of rectangular form and directly engages the support, the hammer having cutting-edges at its corners and a longitudinal slot so that while it is held in radially outstanding position by centrifugal force during operation it is free to reverse itself endwise with respect to the support when the latter is stopped or started. The hammers 23, Figs. 1 and 2, are of oblong shape with a .longitudinal slot 24 to engage a circircumferential series of supporting shafts or bolts 21 connecting a series of discs 16 disposed in spaced relation upon the shaft 18. The hammers may have square ends forming cutting-edges, or the corners may be cut away along slanting lines scalloped' as shown in Fig. 4 so that each corner presents a series of cutting-edges 26. The hammers are. arranged in two helical lines around the support proceeding oppositely towards its ends from an approximately midway point. The ground material falls through the screen 13 into a trough 14 whence it is discharged into a casing 33 by paddles 32 mounted' on a shaft 27 driven by a belt 30 from the shaft 18. A beater-wheel 35 on the shaft 27 throws the material upwardly out of the discharge opening 34 of the casing 33. A vertically-adjustable damper 36 may be fitted at the junction of the trough 14 with the casing 33. The outer end of the trough 14 is fitted with a removable closure-plate 37.