Abstract: An improved expansion assembly for a mine roof bolt has a tapered plug, two expansion leaves that bear against the tapered plug, a bail that connects the expansion leaves and extends over the end of the mine roof bolt, and a breakable holding ring to keep the expansion assembly assembled until after it is placed into the bore hole. The tapered plug has a threaded bore therethrough for threading onto the mine roof bolt. The tapered plug also has tapered surfaces that have an angle of taper of 80.degree. to the axis of the mine roof bolt. The expansion leaves each have nine 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 69.degree. to the planar surface. The serrations are equally spaced from each other and have a peak to peak distance of 0.25". The expansion leaves each have a maximum length of 3".

Abstract: Apparatus and a method for forming various types of woodworking joints on workpieces are provided. A series of templates are provided that, when utilized with the appropriate cutting bit for a router produce the desired joint configuration. The router is mounted below a support platform with the cutting bit of the router extending upwardly through a central aperture in the support platform. A guide bushing fixed to the support platform surrounds the cutter bit. A selected template is fixed to fence posts that extend upwardly from the template. The fence posts secure a fence to the template. The fence has clamps that clamp a workpiece to the fence so that the workpiece can be positioned over the edge patterns on the template. Handles are secured to the fence posts and the fence.