Abstract: A method is disclosed for manufacturing steel bar (10) with intermittent smooth surface segments (11) and patterned relief segments (12). The method includes the steps of heating the bar (10) to a semiplastic state, rolling the semiplastic metal bar between rollers (30) having segments of patterned relief (33) around their respective circumferences separated by intermittent smooth segments (34). The rollers (30) rotate in registration with each other thereby imparting a corresponding intermittent pattern to the surface of the bar (10) along its length. The metal bar is then cooled to a solid state with the intermittent pattern intact on the surface of the bar. The metal bar (10) has intermittent segments of patterned relief (12) separated by intermittent smooth segments (11), the intermittent segments of patterned relief (12) being rolled onto the surface of the bar by passing the bar in a semiplastic state between rollers (30) having corresponding patterned relief (33) around their respective circumferences.

Abstract: A rock formation, such as the roof of a mine tunnel, is reinforced by use of the apparatus of the invention to provide an anchor for a rock bolt which is tensioned to hold a support plate or similar structure in firm engagement with the face of the rock structure. The apparatus includes an elongated bar threadedly engaged with one end of an open, cylindrical coupling member, the other end of which is threaded to receive the rock bolt. One or more fixed members, preferably in the form of integral, die-formed ears, extend outwardly from the bolt shank a predetermined distance from the end of the threaded portion. Prior to threading into the coupling member the end of the bolt is inserted through an open, cylindrical collar having an internal radius greater than that of the bolt shank but less than the radial distance by which the fixed members project outwardly therefrom.

Abstract: A rock formation, such as the roof of a mine tunnel, is reinforced by use of the apparatus of the invention to provide an anchor for a rock bolt which is tensioned to hold a support plate or similar structure in firm engagement with the face of the rock structure. The apparatus includes an elongated bar threadedly engaged with one end of a hollow collar, the other end of which is threaded to receive the rock bolt. An installation tool in the form of an elongated rod is provided at one end with outwardly extending fixed members for engagement with stop surfaces on the other end of the collar. Rotation of the tool is transmitted to the collar and bar to break a resin cartridge within a blind drill hole in the rock formation and mix the contents thereof. Upon hardening of the resin mixture about the bar, the installation tool is withdrawn and the rock bolt carrying a roof support plate is threaded into the anchored collar and tensioned to the desired degree.

Abstract: A support assembly for a mine roof, or the like, including a bolt carrying a support plate for engagement with the roof surface, an internally threaded cylindrical collar, and an elongated bar. The bar and bolt are threaded into opposite ends of the collar, the bar being threaded to a fixed stop and the bolt being threaded to a deformation at an intermediate point along the length of the collar threads. A conventional resin package is inserted in the bore hole and the assembly inserted behind it with the end of the bar contacting the package to effect rupturing thereof and mixing of the contents. Rotation of the bolt is transmitted through the collar to the bar as the resin components are mixed due to engagement of the bolt with the deformation in the collar threads. After the resin has hardened the bar and collar cannot be further rotated.