Abstract: A method of opening a mine door leaf installed in a mine passageway having a high pressure zone and a low pressure zone. The method includes the steps of operating a variable-throw crank mechanism in a first configuration having a first crank length to apply a first force to the mine door leaf to move at a first speed, operating the variable-throw crank mechanism in a second configuration having a second crank length less than the first crank length to apply a second force greater than the first force to the mine door leaf to move at a second speed slower than the first speed, and using a resistance pressure associated with the high and low pressure zones in the mine passageway to convert the variable-throw crank mechanism from the first configuration to the second configuration.

Abstract: A mine ventilation structure is disclosed. The structure comprises a deck including a plurality of elongate sheet metal panels. Each panel is generally of inverted channel shape in transverse cross-section, having a top web and first and second sides extending down from the top web. The panels are connected by tongue-and-groove connections between adjacent sides of adjacent panels. A mine ventilation deck panel of desired construction is also disclosed.

Abstract: A mine stopping panel and method of making it are disclosed. In one embodiment, the panel includes first and second channel-shaped panel members having a telescoping sliding fit one inside the other. An elongate end cap fitted in the first panel member. One or more connections between the first panel member and the end cap hold the end cap against movement relative to the first panel member when an extending force is applied to the end cap tending to telescopically extend the first panel member relative to the second panel member. At least one device on the end cap is configured for engagement with the first panel member to resist telescopic movement of the first end cap relative to the first panel member when a contracting force is applied to the first end cap. Other improved mechanisms for resisting contracting forces are disclosed.

Abstract: A conveyor belt box check for installation in a mine is disclosed. The box check includes first and second generally parallel spaced-apart walls extending across a mine passage. Each of the walls has a conveyor belt aperture sized for receiving the conveyor. In some embodiments, access doors are provided in the first and second walls, and a partition extends between the first and second walls for separating the access doors from the conveyor belt apertures and for forming an air lock between the walls. A method of installing the box check is also disclosed.

Abstract: A method of opening a mine door leaf installed in a mine passageway having a high pressure zone and a low pressure zone. The method includes the steps of operating a variable-throw crank mechanism in a first configuration having a first crank length to apply a first force to the mine door leaf to move it at a first speed, operating the variable-throw crank mechanism in a second configuration having a second crank length less than the first crank length to apply a second force greater than the first force to the mine door leaf to move it at a second speed slower than the first speed, and using a resistance pressure associated with the high and low pressure zones in the mine passageway to convert the variable-throw crank mechanism from the first configuration to the second configuration.

Abstract: A conveyor belt box check for installation in a mine is disclosed. The box check includes first and second generally parallel spaced-apart walls extending across a mine passage. Each of the walls has a conveyor belt aperture sized for receiving the conveyor. In some embodiments, access doors are provided in the first and second walls, and a partition extends between the first and second walls for separating the access doors from the conveyor belt apertures and for forming an air lock between the walls. A method of installing the box check is also disclosed.

Abstract: A mine door system comprising at least one mine door leaf hinged at one side thereof to a door frame defining an entry. The system includes an articulated door-moving mechanism that articulates between a first configuration in which the mechanism applies a relatively small door-moving force to the door leaf to move the door leaf at a first speed and a second configuration in which the mechanism applies a larger door-moving force to the door leaf to move the door leaf at a second speed less than the first speed. A related method is also disclosed.

Abstract: A mine refuge for use in a mine includes a chamber sized and shaped for occupancy by at least one miner and adapted to be substantially sealed. An oxygen supply is installed in the chamber for supplying oxygen to the chamber. A breathable air supply is installed in the chamber for supplying a steady flow of breathable air and for positively pressurizing the chamber to inhibit entry of contaminated mine air into the chamber.

Abstract: A mine stopping panel is disclosed. The panel includes first and second channel-shaped panel members having a telescoping sliding fit one inside the other. An elongate end cap fitted in the first panel member defines a cavity for receiving an end seal for sealing engagement with a mine surface. One or more louver connections between the first panel member and the end cap hold the end cap against movement relative to the first panel member when an extending force is applied to the end cap tending to telescopically extend the first panel member relative to the second panel member.

Abstract: This invention is directed to an electrically non-conductive tie for use in a mine seal having opposing walls defining a space for receiving filler material. The tie has opposite ends, a length and a width and is made at least in part from an electrically non-conductive material which extends across substantially the entire width of the tie for preventing conduction of electrical current from one end of the tie to the other. Openings are provided adjacent opposite ends of the tie for receiving wall supports for the mine seal.

Abstract: A mine seal comprising two spaced apart walls, at least one electrically non-conductive tie extending between the walls and holding them in place against forces tending to separate the walls, and a filler material filling the space between the walls. A form for making such a mine seal is also disclosed.

Abstract: A mine ventilation and bridge structure incorporating a bridge feature enabling a mine vehicle to cross over the structure. The structure comprises a pair of generally parallel and spaced-apart side walls defining opposing side walls and a plurality of elongate deck panels extending between the side walls. At least one deck panel of the plurality of deck panels is a reinforced bridge deck panel constructed to support the weight of a vehicle crossing over the mine ventilation and bridge structure.

Abstract: A high-strength anchor system for anchoring a support to mine strata is disclosed. The system includes an anchor plate and a connecting member on the anchor plate for connection of the support to the anchor plate. Anchor bolts extend through bolt holes in the anchor plate into bore holes in the mine strata. Load-spreading devices extend from respective bolt holes in the anchor plate into the bore holes. The load-spreading devices have outside diameters larger than outside diameters of the anchor bolts for spreading shear loads exerted on the anchor bolts over larger areas of the mine strata. A method of installing such a system and a safe room bulkhead using such a system are also disclosed.

Abstract: A high-strength anchor system for anchoring a support to mine strata is disclosed. The system includes an anchor plate and a connecting member on the anchor plate for connection of the support to the anchor plate. Anchor bolts extend through bolt holes in the anchor plate into bore holes in the mine strata. Load-spreading devices extend from respective bolt holes in the anchor plate into the bore holes. The load-spreading devices have outside diameters larger than outside diameters of the anchor bolts for spreading shear loads exerted on the anchor bolts over larger areas of the mine strata. A method of installing such a system and a safe room bulkhead using such a system are also disclosed.

Abstract: A mine refuge for use in a mine includes a chamber having an interior space sized and shaped for occupancy by at least one person. An oxygen supply is installed in the chamber for supplying oxygen to the chamber. A mask is operatively connected to the oxygen supply and is adapted for donning by the person to supply oxygen to the person. In some embodiments, an air supply in addition to the oxygen supply is provided.

Abstract: A mine door system comprising at least one mine door leaf hinged at one side to a door frame defining an entry. The system includes an articulated door-moving mechanism that articulates between a first configuration in which the mechanism applies a relatively small door-moving force to the door leaf to move it at a first speed and a second configuration in which the mechanism applies a larger door-moving force to the door leaf to move it at a second speed less than the first speed. A related method is also disclosed.

Abstract: A differential temperature display system for balancing hydronic systems includes a first sensor for sensing a supply temperature and for outputting a first signal indicating the supply temperature. A second sensor is adapted for sensing a return temperature and for outputting a second signal indicating the return temperature. At least one integrated circuit is adapted for calculating a differential between the supply and return temperature. A single electronic display is adapted for displaying one of the supply temperature and the differential. A method of using the system is also disclosed.

Abstract: A hydraulic system has a hydraulic actuator for moving a door leaf of a door installation between open and closed positions thereof. A reservoir has a volume for containing a hydraulic fluid. A fluid circuit provides fluid communication between the hydraulic actuator and the reservoir. The system also has a pump for pumping hydraulic fluid from the reservoir into the fluid circuit to operate the actuator. A fluid circuit flushing system of the hydraulic system operates to flush a volume of hydraulic fluid from the fluid circuit back to the reservoir without moving any door leaves of the door installation. The hydraulic system may be part of a mine door installation installed in a mine passageway and having at least one door leaf. The hydraulic actuator is connected to the door leaf for driving movement of the door leaf between its open and closed positions.

Abstract: A mine ventilation and bridge structure incorporating a bridge feature enabling a mine vehicle to cross over the structure. The structure comprises a pair of generally parallel and spaced-apart side walls defining opposing side walls and a plurality of elongate deck panels extending between the side walls. At least one deck panel of the plurality of deck panels is a reinforced bridge deck panel constructed to support the weight of a vehicle crossing over the mine ventilation and bridge structure.

Abstract: A mine seal comprising two spaced apart walls, at least one electrically non-conductive tie extending between the walls and holding them in place against forces tending to separate the walls, and a filler material filling the space between the walls. A form for making such a mine seal is also disclosed.