GB525564A - Improvements in or relating to guards for machines comprising rollers arranged in pairs - Google Patents

Abstract

525,564. Grinding-machines. HOVIS, Ltd., and NOBLE, H. G. Feb. 22, 1939, No. 5932. [Class 59] [Also in Group XXIV] In machines for grinding or crushing material fed under gravity to at least one pair of rollers, a finger guard is provided adapted to prevent the fingers of an attendant from becoming caught in the nip of the rolls. As applied to a flour mill, a pair of rollers 10, 12, are enclosed in a casing 14 having an inlet 16 and an inspection opening 18 and cover 20. The material to be ground falls from the inlet 16 on to feed means comprising two grooved feed rollers 26, 28 having a downwardly slanting plate 30 between them and a back plate 32 of substantially triangular section, having a smooth front surface 34 of shiny tin arranged near the roll 12 and close to the roller 28. The guard is in the form of a foursided bar 38 applied to the top roll 10 to close substantially the space between this roll and the feed roller 28, except that a feed gap is left at 40. The bar, in cross-section, is of trapezoid form with the sides 42 ... 44 flat and the side 45 also flat but preferably arcuate and struck from the axis 22 of the roll 10. To prevent material collecting on the bar 38 its front edge 46 is relatively sharp. The guard may be situated at a lower level. Both the back plate 32 and the guard 38 are carried at their ends by two upright members 48 each having a curved finger grip 58 and a hook 52 to hang over a stud 56. In a modification, Fig. 3, the axes of the rolls 60, 62, lie in a vertical plane, a curved back plate 66 extends downwardly from a feed roller 64 to just below the nip of the rolls and a finger guard 68 is mounted independently of the back plate 66. The lower face 70 is concave and concentric with the roll, the upper face 71 being substantially tangential to the roll. In a further modification, with a pair of rolls whose axes are in the same horizontal plane, two bars are employed each forming a guard and spaced apart a distance sufficient to form a feed gap. In a still further modification, two pairs of vertical rolls are used, with back plates and the guards are arranged similarly to that in Fig. 3, except that the face 73 in Fig. 3 is replaced by a sharp edge.