Abstract: A hammer assembly for a rotary material crusher having a rotor. The hammer assembly includes a hammer member and a base member. The base member is mounted at one of its ends on the rotor. The hammer member is mounted on the other end of the base member. The hammer member and base member each have two pairs of concave and convex surfaces, one for absorbing centrifugal forces and the other for absorbing impact forces and meshing, one surface with the other. The pair of concave and convex surfaces for absorbing centrifugal force are behind of the centrifugal force radial line of the hammer member in the direction of rotation of the rotor.

Abstract: A hammer assembly for attachment to a rotor of a rotary material crusher is disclosed. The hammer assembly includes a hammer member rigidly connected to the rotor and an extension of the hammer member having a longitudinal axis disposed parallel and spaced relative the axis of rotation of the rotor. The extension has a uniform transverse cross-sectional configuration along the length of the extension. A cap means is removably connected to the extension for crushing the material on rotation of the rotor, the cap defining an undercut portion which cooperates with the extension for locking the cap adjacent the hammer member.

Abstract: A wedge and clamp device for retaining a wedge in a slot of a disc and against a breaker bar of a rotor assembly in an impact crusher. The clamping arrangement comprises a sleeve which is placed inwardly in the slot, two plates each mounted along the opposed outer faces of the disc in alignment with the sleeve and a bolt extending through the sleeve and two plates. The wedge has a U-groove along its top surface to receive the opposite edges of the disc, and the two plates overlap the wedge so that the wedge can move in a direction out of the slot to increase the holding force against the breaker bar during operation of the crusher.

Abstract: In an impact crusher for reducing the size of particulate material, the breaker bars having one or more quasi-circular depressions for engaging a circular back-up bar is secured to a rotor by means of a serrated wedge and C-clamp assembly. A newly designed housing opening permits the breaker bars to be placed in an optimum horizontal positioning and a rotor-locking assembly holds the back-up bars in this optimum positioning and provides support for the breaker bars during replacement thereof.