Patent ID: 7975949

Claim:
A hammer assembly for attachment to a rotor of a rotary material crusher, said rotor having a periphery portion and opposing ends, and being driven to rotate about an axis of rotation extending through the ends, said hammer assembly comprising: an adaptor, having a base portion and a hammer mounting portion, with the base portion being attachable to said rotor at the periphery portion so as to align a longitudinal axis of the adaptor parallel to the axis of rotation of the rotor, said adaptor having apertures extending through the hammer mounting portion in a direction parallel to the longitudinal axis of the adaptor, with all apertures in alignment with each other, and a hammer, having at least one impact portion, for crushing material, and a mounting portion for engagement with the hammer mounting portion of the adaptor so as to align a longitudinal axis of the hammer parallel to the axis of rotation of the rotor, wherein the hammer mounting portion of the adaptor includes bearing surfaces facing a direction of impact when crushing material, and the mounting portion of the hammer includes bearing surfaces for mating with the bearing surfaces of the hammer mounting portion of the adaptor, the hammer assembly further comprising: a retainer rod, and at least one retainer pin having one end with a head and an other end with an aperture, said end with an aperture for passing through an opening in the hammer and said end with a head for engaging with the hammer at said opening in the hammer, wherein when the hammer is attached to the adaptor, the retainer rod passes through the apertures of the adaptor and the apertures of each retainer pin in the direction of the longitudinal axes of the hammer and the adaptor, and the size of the retainer rod, the size of the apertures of the adaptor and the size of the aperture of each retainer pin are selected such that the hammer is free to move to enable the bearing surfaces of the hammer to bear on the bearing surfaces of the adaptor and transfer impact forces when impact forces from crushing material are applied, with said retainer rod being free from any of the impact forces.