A rock bit for drilling subterranean formations has an improved dynamic O-ring seal for retaining lubricant around the rock bit bearings during operation of the rock bit. Such a bit has a plurality of journal pins, each having a bearing surface, and a cutter cone mounted on each journal pin and including a bearing surface. A grease reservoir is in communication with such bearing surfaces for maintaining grease adjacent to the bearing surfaces. The grease is sealed in with dynamic O-ring seals ro...

A rock bit is disclosed having a plurality of rolling cone cutters each having a gage row of inserts oriented to face the borehole bottom for crushing the same, and a second row of heel gage inserts which are oriented to face the borehole sidewall for scraping the same, heel inserts are nestled within the profile of the gage inserts in order to alleviate most of the scraping action normally encountered by gage inserts.

A rock bit is provided that comprises a generally cylindrical body with a leading end for boring in a rock formation and a trailing end for connection to a drill rod. The body has a generally cylindrical outside surface and comprises a plurality of parallel longitudinal grooves circumferentially spaced around the outside surface and extending from the leading end to the trailing end. The grooves have a depth that increases from the leading end to the trailing end such that the cross-sectional ar...

A drilling tool and, in particular, a rock drill for the creation of breaches in concrete or masonry for the use of drill hammers is proposed, which is configured as a cross drill bit having four cutting fins. In order to optimize drilling capacity, the drilling tool is provided with a cross drilling head which merges in one piece into a conveyor spiral matched to the drill head. A purpose-specific cutting element facing serves to optimize the drilling capacity.

A drive nut (3,7) for a rock bolt, incorporating a nut (7) with a crimped protrusion (9), and an insert (3). The protrusion is crimped to form a plurality of lips (8) adapted to retain insert (3) in the head of the nut (7), the crimping being effected by a pressing tool having a number of preferably square bars. By this crimping technique, the drive nut (3,7) can be fabricated in such a way that the breaking torque required to expel the insert (3) from the nut (7) can be limited to a predetermin...

A rock drill is provided in which an optimum support of the carbide cutting tip or of a cross cutting edge is achieved by the drill head being made square or rectangular in cross-section. This results in an optimum strengthening of the cross-section against fracture in the slot root for the cutting tips. Moreover, catching of the drill in fissured rock and under extreme loads such as in reinforcement drill holes is avoided.

A rock drill haivng a drill head with cruciform cutting tips is proposed which has improved chiselling properties in the case of percussive loading in hard rock or the like. For this purpose, the main cutting tip (4) is of a design know per se with secondary cutting tips (7,8) which are arranged transverse thereto and have a roof-shaped cross-section in side elevation. Additional, radially further outward bit points (16) for working the material result from the roof-shaped cross-section of the s...

Hydraulic control system for controlling the movement of the movable jaw of a rock crusher between a first set position and a retracted position. The control system includes a double acting hydraulic ram having first and second ends mounted on the frame of the rock crusher and movable jaw respectively. A source of high pressure hydraulic fluid provided. A first fluid supply conduit communicates between the source of high pressure fluid and a first fluid chamber of the ram. A second fluid supply ...

A rock drill for rotary and/or percussive stress, in particular for use in percussion or hammer drilling machines, is proposed, which by its geometrical design makes improved efficiency and simplified production possible. For this purpose, the feed spiral 5 is designed alternately with horizontal feed sections 8,8' with a 0.degree. pitch, and adjoining lead sections 9,9', the respective feed sections assuming an angle of rotation of 90.degree. on the drilling tool.

A drill including a stem (2) having at least two discharge grooves (3,4) for discharging drilling dust and helically circumscribing the stem (2), a drill head (5) provided at an of the stem (2) opposite the end provided with the shank and having a plurality of bits (7-9), which are formed of hard metal and project radially beyond the drill head (5), with the drill head having a plurality of drilling dust grooves (10-12) which separate the bits and number of which exceeds a number of the discharg...