A rock drill includes an axially elongated shank with a chucking shank part (1) at one end, a drilling shank part (2) extending from the chucking shank part and having at least four drilled material conveying flutes (4, 5, 6, 7) disposed next to one another in a parallel manner, and a drilling head at the opposite end of the shank and formed of hard metal and having four removal flutes (8, 9, 10, 11) spaced apart about its outer circumferential surface. The removal flutes have transverse cross-s...

The present invention relates to a device for setting rock bolts. The device employs a common element for affixing the end of a feed shell with respect to a rock surface, stabilizing the feed shell and providing a common centralizer for centering all subsequent bolt setting operations. The device also has a bolt magazine which stores, advances and positions the bolts in line with a bolt driver.

This invention relates to improvements and modifications to a rock crusher. The rock crusher has at least two jaws the jaws being driven at different ends to each other. The non-driven end of at least one jaw is sufficiently free to allow vertical movement of that jaw with respect to the other jaw. This vertical movement imparts a grinding action in addition to the crushing action of the rock crusher. This removes the problems which can occur with wadding and can produce a very fine ground rock.

The rotor of a vertical shaft impact rock crusher is balanced by placing steel balls in a hollow ring attached around the top of the rotor. The vanes within the impeller are constructed to form rock shields on the forward or impact side of the vanes. Rocks are fed into the impeller upon a free floating table. The top of the free floating table is protected by a tungsten carbide disc. Therefore the rocks are moved from the table at reduced rotational velocity less than that of the rotor and are s...

A device for cutting trenches in hard rock. A plurality of disc-like primary cutters are positioned on arms around a frame. The frame rotates about a central shaft and the center shaft is moved along horizontally in the direction the trench is to be cut. Between the primary cutters are reaming cutters. Each primary and each reaming cutter is provided with a plurality of spaced apart indentors secured to the external surface and each indentor has an end point and being adaptable to penetrate the ...

A rock bolt is provided for insertion into a bore in the roof or side wall of an underground opening so as to stabilize the roof or wall of the opening. The rock bolt comprises a generally hollow elongate body having a side wall wherein the side wall has a flute formed from a pair of inwardly disposed wall portions interconnected at their respective inboard ends to form a hinge. The hinge is responsive to forces applied to and along the side wall by the bore so that the rock bolt may be deformed...

A rock drill has an axially extending shank (1) with a drill head (2) on one end. The drill head (2) has an end face (3) with a cutting blade (4) and cutting pins (5) extending outwardly from the end face in the drilling direction. The cutting blade (4) extends diametrically across the end face and projects radially outwardly from the drill head (2) and axially outwardly from the end face (3). The cutting pins (5) are arranged on a diameter of the drill head which forms an acute angle relative t...

A device and method are set forth for crushing rocks. The device includes first and second rotors defining therebetween a nip for crushing rocks. A feed opening is provided to feed rock between the rotors to the nip. Angular shoes on the second rotor direct rocks between the openings. In a further aspect, the second rotor may have a non-circular perimeter such as a pentagon or the like.

A rock drill has an axially extending drill shaft (2) with at least one helically shaped drilled material removal groove (3) and a drillhead (5) formed of a hard metal alloy. The drillhead (5) is secured to an end face of the drill shaft (2) such as by welding or soldering and has a main cutter (6) extending along a diagonal of the drillhead and at least one supplementary cutter (7, 8) extending along another diagonal of the drillhead. The supplementary cutter (7, 8) projects axially outwardly f...

A rock drill for hammer drilling machines is proposed, which has a helical shank and a drill head which is connected thereto and on whose end face are arranged a main cutting tip inclined in the shape of a roof and also auxiliary cutting tips disposed transversely thereto. The drill head has two laterally opposite flats for the formation of drilling dust grooves. In plan view the drill head has a very largely rectangular shape in cross section, an acute angle .beta..sub.1 being enclosed between ...