Abstract: A tensionable mine roof cable bolt having a resin grouted upper portion and a mechanically anchored lower portion. The lower portion includes a shaft which is swaged to the cable and accepts a mechanical anchor. The cable bolt is rotated during installation in a mine roof to mix resin and simultaneously engage the mechanical anchor with the rock. A drivehead attached to the lower end of the cable fails upon tensioning of the bolt to a predetermined load.

Abstract: A tapered camming plug positioned within an expansion shell is threaded onto an upper end portion of an elongated bolt advanced behind a resin cartridge system into a bore hole drilled in a rock formation. A bearing plate is carried on the opposite end of the bolt and abuts the rock formation surrounding the bore hole. The cartridge is ruptured by upward thrust and rotation of the bolt to release the resin components for mixing. The mixed resin flows downwardly in the bore hole into surrounding relation with the camming plug and expansion shell. The expansion shell includes a plurality of expansion fingers each formed integral at one end portion with a ring end portion of the shell and extending upwardly to a free end portion for outward expansion into engagement with the wall of the bore hole as the camming plug advances downwardly on the bolt after the resin is mixed.

Abstract: An improved expansion assembly for a mine roof bolt for use in a nominal one inch diameter bore hole with a nominal 5/8" diameter roof bolt is provided. The expansion assembly has a tapered plug with four tapered surfaces, an expansion shell that has four leaves extending axially upwardly from a support ring and into contact with the four tapered surfaces on the tapered plug, and a threaded support washer to support the expansion shell on the threaded end of a mine roof bolt. The tapered plug has a threaded bore therethrough for threading onto the mine roof bolt. The tapered plug tapered surfaces have an angle of taper of at least 6.5.degree. to the axis of the mine roof bolt. The expansion leaves each have seven serrations formed on the surface such that the serrations are formed by the intersection of a planar surface perpendicular to the axis of the mine roof bolt and a frusto-conical surface. The frusto-conical surface is at an angle of 72.3.degree. to the planar surface.

Abstract: An improved expansion assembly for a mine roof bolt for use in a nominal one inch diameter bore hole with a nominal 5/8" diameter roof bolt is provided. The expansion assembly has a tapered plug with four tapered surfaces, an expansion shell that has four leaves extending axially upwardly from a support ring and into contact with the four tapered surfaces on the tapered plug, and a threaded support washer to support the expansion shell on the threaded end of a mine roof bolt. The tapered plug has a threaded bore therethrough for threading onto the mine roof bolt. The tapered plug tapered surfaces have an angle of taper of at least 6.5.degree. to the axis of the mine roof bolt. The expansion leaves each have seven serrations formed on the surface such that the serrations are formed by the intersection of a planar surface perpendicular to the axis of the mine roof bolt and a frusto-conical surface. The frusto-conical surface is at an angle of 72.3.degree. to the planar surface.

Abstract: An elongated rod with an expansion shell assembly positioned on the upper end thereof is advanced into a bore hole drilled in rock formation behind a resin cartridge system. The lower end of the rod is connected by a coupling to the upper end of a bolt having a bearing plate positioned on a lower end of the bolt emerging from the bore hole. Unitary rotation of the rod and bolt in a preselected direction while maintaining the shell assembly in an unexpanded condition effects mixing of the resin components in the bore hole. Continued rotation of the rod and bolt after the resin components are mixed effects expansion of the shell into engagement with the wall of the bore hole to anchor the rod in the bore hole.

Abstract: An improved roof support system for a mine or the like is of the type which includes a pair of plates secured to the roof of the mine at opposite sides thereof adjacent opposing ribs of the mine and a horizontal, transverse reinforcing member extending between the pair of plates. The improvement includes the reinforcing member having a first rod with a first end thereof secured to a first of the plates and a second end extending toward the second plate. The second plate includes a vertical portion with a transversely extending opening therethrough. The reinforcing member also includes a second rod in the form of a bolt which has a bolt head located against the vertical portion of the second plate with the threaded second end thereof extending through the opening toward the first plate. The second end of the first rod includes a sleeve mounted thereon having a threaded bore therethrough for receipt of the threaded end of the bolt.