GB1454288A - Shredding machines - Google Patents

Abstract

1454288 Shredding apparatus METAL BOX Ltd 7 Nov 1974 [7 Nov 1973] 51705/73 Heading B2A Shredding apparatus capable of reducing large tyres comprises contra-rotatable parallel cutter shafts 14, Fig. 3, supporting disc-like cutter members 21, 22 arranged in assemblies 19, 20 of cooperating pairs. The cutting edges at the periphery 30 of each cutter element 24, are such that when the assemblies 19, 20 are contra-rotated at the same speed the "included angle" A between two cooperating cutters is small enough to cause positive cutting between them. This "included angle" is the angle at any point on the periphery of a first of the cutter elements between the tangent to the periphery at that point, and the tangent to the periphery of the second of the cutter elements at a point which, during contra-rotation of the cutter assemblies, meets the said point on the first cutter element, whereby the two said points instantaneously define the rearward extremity of overlapping portions of the two respective cutter elements The cutters may have a six point profile as in Fig. 3 or a 3-point profile Fig. 8. The apparatus includes guides 55 to guide material away from the cutting zone 23. Automatic reversal to clear jams and/or resilient mounting guides 55 is provided. A pusher is included for urging tyres into the apparatus. The modified apparatus with 3-point cutters includes extra bearing supports 82, 83 Fig. 7, and inlet guide assemblies 90 and top guides 91, Fig. 6. In alternative embodiments the cutter may have four or five teeth. In all cases material can recirculate if desired, passing more than once through the cutter assemblies.