Abstract: A compressible support used to support mine roofs. The compressible support generally includes a male member which adjustably engages a collar and may further include a cap and a wooden base. A post may also be provided. The male member defines ridges and grooves and the collar defines corrugations, each preferably in the form of modified buttress threads, which yield, fracture, or strip when the compressible support is subjected to additional force, decreasing the overall length of the compressible support.

Abstract: The present invention relates to compressible supports used to support mine roofs. The compressible support generally includes a male member which adjustably engages a collar and may further include a cap and a wooden base. A post may also be provided. The male member defines ridges and grooves and the collar defines corrugations, each preferably in the form of modified buttress threads, which yield, fracture, or strip when the compressible support is subjected to additional force, decreasing the overall length of the compressible support.

Abstract: A cribbing system for supporting a mine roof or the like includes a multi-sided column. Each column is formed of a stack of cribbing elements with each cribbing element having upper and lower surfaces wherein substantially the entire upper and lower surface of each cribbing element is a bearing surface for transmitting a substantially vertical load to a vertically adjacent cribbing element of one stack. Each cribbing element is interconnected with at least one cribbing element of an adjacent side. The interconnection between interconnected cribbing elements is formed by a slot extending through one of the interconnected cribbing elements in the direction of the column and a matching projection on at least the other interconnected cribbing elements, with each projection extending in the direction of the column for the height of the cribbing element. The cribbing system may be a wooden cribbing system having two distinctly different sets of cribbing elements.

Abstract: A mine cribbing system includes a mine cribbing column having a discrete number of sides, each side including a series of stacked blocks. Each block includes an elongated body and a pair of spaced slots extending into one side of the body. The slots are utilized for interconnecting the adjacent sides. Preferably, the column is a three-sided structure with a first pair of slots in each body extending 1/3 of the thickness of the body and a second slot of each body extending in 2/3 of the thickness of the body.