Abstract: The invention concerns blow bar 1 for impactor rotors with a mirror-symmetrical longitudinal cross-section for the purpose of reversibility, which is fitted in peripheral recesses 17 of the rotor advantageously comprising discs 16. According to the invention, the cross-section of blow bar 1 essentially forms a basic double trapezium shape with the wide bases of each trapezium as symmetrical axis 2. The rear 5 of the blow bar corresponding to the height of each trapezium is arranged at rightangles to the symmetrical axis and forms a level surface 6 over the total height of the blow bar. The invention also specifies an advantageous rotor for such a blow bar, Fig.

Abstract: The invention concerns an impact crusher 1 with a rotor 3 equipped with blow bars 4 and pivotably-mounted impact aprons 5, 6 arranged in the crusher housing 2, the impact aprons are positionable vis a vis the rotor by means of hydraulic cylinder-piston units 7 via piston rods 8. In a prior art impact crusher, additional mechanical devices are provided locally alongside the hydraulic retaining and positioning device 7, 9 to prevent the impact aprons 5 dropping into the tip circle circumscribed by the blow bars 4 of the rotors 3 in case of failure of the hydraulics. The invention provides additional devices connected to the corresponding hydraulically-actuatable retaining and positioning device 7, 9, using the latter's piston reds 8 to form homogeneous units 12.

Abstract: The impactor includes a grinding face 4 disposed underneath the impact aprons 3 at the side of the housing 1 opposite the feed material inlet, the grinding face partially extending under the rotor 2 and connected with a hinged rear housing wall 5 so that it executes a movement away from the rotor when the rear housing wall swings outwards. According to the invention, the grinding face 4 movably rests on a base member 15, a rail or plate, attached to the housing 1, and the lower part of the grinding face 4 is pivotally connected to the rear housing wall 5 by a first linking element 11 at a pivot point 18 located above the pivot element 6 of the rear housing wall 5, and the upper part of the grinding face 4 is pivotably connected to the rear housing wall 5 by a second linking element 12 at a pivot point 19 located a greater distance away from the pivot element 6 than pivot point 18.

Abstract: A rotor for use in an impact crusher or in a hammer mill is assembled of two or more coaxial metallic discs having neighboring hubs and axially spaced apart radially outermost portions which define annular clearances for introduction of a welding implement. Such implement is used to apply annular welded seams which bond the ends of the hubs to each other. The welded seams are provided at the peripheral surfaces of the hubs. The hubs are mechanically coupled to each other by bolts prior to making of the welded seams. The radially outermost portions of the discs are thereupon connected with hammers or beater bars, depending on the intended use of the rotor.

Abstract: A rotor (1) for impact or hammer mills is formed out of several rotor disks (1) made of cast steel and welded together, where the rotor disks exhibit hubs (3) contacting each other at annular sections representing the longest extension of the rotors in an axial direction. The rotor disks are connected to each other by annular weld seams at the hubs. According to a further embodiment of this rotor, the turn-outs (17), furnished for the weld seams (9) at the front faces of the hubs (3), extend from the outer edges over a substantial part of the radial thickness of the hubs, and the weld seam grooves (16), formed by the turn-outs of the neighboring rotor disks, are filled with welding materials.