Abstract: A testing apparatus includes a frame having a top end and a bottom end, a weight block movable between the top end and the bottom end, a guide member supported by the frame and receiving the weight block, and a protection mechanism having a stopper and an actuator. The stopper being operatively connected to the actuator and movable between an extended position and a retracted position with the stopper being configured to restrict the movement of the weight block when in the extended position.

Abstract: A steel set assembly includes a first pair of legs and a second pair of legs with the first pair of legs being spaced from and positioned opposite the second pair of legs. First and second beams are provided with the first beam being secured to one leg of the first pair of legs and one leg of the second pair of legs. The second beam is secured to the other leg of the first pair of legs and the other leg of the second pair of legs. A panel is secured to the first and second beams and includes a base having a top surface and a bottom surface, a block having a top surface and a bottom surface, and a pad. The block is secured to the base and the pad is positioned between the top surface of the base and the bottom surface of the block.

Abstract: A steel set assembly includes a first pair of legs and a second pair of legs with the first pair of legs being spaced from and positioned opposite the second pair of legs. First and second beams are provided with the first beam being secured to one leg of the first pair of legs and one leg of the second pair of legs. The second beam is secured to the other leg of the first pair of legs and the other leg of the second pair of legs. A panel is secured to the first and second beams and includes a base having a top surface and a bottom surface, a block having a top surface and a bottom surface, and a pad. The block is secured to the base and the pad is positioned between the top surface of the base and the bottom surface of the block.

Abstract: A mine roof support includes a substantially dome-shaped plate including a curved portion having a first side and a second side. The mine roof support includes a drive end such as a barrel and wedge assembly, a nut or a forged head. The first side of the plate is adapted to mate with a recess defined in a mine roof. A top portion of the drive head may be contoured to substantially match the contour of the second side of the plate. A drill bit tool used to create the recess includes a first drill bit situated at one end of the drill bit tool and a second drill bit situated near an opposite end of the drill bit tool, wherein the drill bit tool is adapted to drill a bore hole and the recess. A method for supporting the mine roof utilizes the mine roof support.

Abstract: A truss shoe for a roof support system includes a base member having a bearing surface and, optionally, an end having a sweeping radius for ease of moving the truss shoe into an installation position, a bolt receiving section having a bore hole, a cable engaging section, and an intermediate section. The cable engaging section includes an opening and a slot and, optionally, a lock-in device that allows a cable to move through the slot into the opening and retains the cable in the opening. In another non-limiting embodiment of the cable engaging section, the cable is moved into an assembly mounted in a conical-shaped passageway of the cable engaging section to compress the assembly around the cable. The intermediate portion includes a pair of side flanges on the base member between the bore and the opening and, optionally, a rib between the pair of side flanges.

Abstract: A yieldable prop having a first end and a second end including a first hollow conduit, a second conduit slidably received in the first hollow conduit, a clamp assembly positioned adjacent to the first hollow conduit and the second conduit, and at least one handle connected to the first hollow conduit and the clamp assembly. The prop further includes a bearing plate positioned at the first end of the yieldable prop, wherein the bearing plate is selected from a shape comprising planar and volcano.