Abstract: A surface plate for supporting generally planar loads, specifically mine roofs. The present invention generally relates to a surface plate that is capable of supporting a mine roof. Surface plates in accord with the preferred embodiments of the present invention comprise a plurality of embossments. The embossments provide the surface plates with increased strength when compared against the prior art. In the preferred embodiments, one of the plurality of embossments is a continuous perimeter embossment that generally parallels the outer perimeter of the surface plate. Another of the plurality of embossments is a circular embossment located at the center of the surface plate wherein a central opening through which a mine roof bolt is received is located. The preferred embodiments may further comprise a plurality of radial embossments that extend from the central embossment to the perimeter embossment. These radial embossments may be arranged in a regular pattern around the central embossment.

Abstract: An apparatus and method for anchoring a bolt in a bore hole in a rock formation is disclosed. A tensioning assembly, which comprises a tensioning plug and expandable sheath, is threadedly engaged to the end of an elongated bolt. A ring is securely affixed to the inner wall of the plug at a predetermined point adjacent the plug's threaded portion. The end of the bolt abuts the ring upon assembly, thereby causing the bolt and the tensioning assembly to rotate together upon application of a torque to the bolt. This rotational movement effects mixing of bonding material which is placed in the bore hole ahead of the tensioning assembly. As the mixed bonding material begins to harden, rotation of the tensioning assembly is resisted.

Abstract: An apparatus and method for anchoring a bolt in a rock formation is disclosed, and includes a rebar assembly adapted for use in a bore hole and an elongated bolt threadedly engaged to the end of the rebar. A threadable sleeve is securely affixed in an orifice, forged in the end of the rebar, at a predetermined point adjacent the orifice threaded portion. The end of the bolt abuts the sleeve upon assembly, thereby causing the bolt and the rebar assembly to rotate together upon application of a torque to the bolt. This rotational movement effects mixing of bonding material which is placed in the bore hole ahead of the rebar assembly. As the mixed bonding material begins to harden, rotation of the rebar assembly is resisted. Upon application to the bolt of a torque in excess of a predetermined torque, the bolt will thread the sleeve located in the rebar orifice by cutting threads therein, thereby causing relative rotational movement between the rebar and the bolt.