Abstract: A system for controlling a first device having a first input for controlling operation of the first device and having a first output indicating status of the first device, and a second device operating in conjunction with the first device and having a second input for controlling operation of the second device and having a second output indicating status of the second device. The system includes first and second serial sequencers. The first serial sequencer controls the first device, wherein the first output of the first device is a first shared output. The first sequencer has an input connected to the first shared output of the first device for monitoring the status of the first device, and has an output connected to the first input of the first device for controlling operation of the first device.

Abstract: A method for reducing the sulfur content in combustion gases from burning coal includes the steps of applying opposite electrostic charges to fuel particles and to reaction particles, and mixing the oppositely charged particles prior to combustion to facilitate the formation of sulfur compounds from sulfur in the fuel upon combustion of the fuel, to thereby reduce the sulfur content in the combustion gases. The reaction particles are preferably a carbonate such as CaCO.sub.3 and MgCO.sub.3. The apparatus for implementing the method includes a first pneumatic line for conveying fuel particles, and a first electrostatic charging device for applying an electrostatic charge to the fuel particles conveyed in the line; and a second pneumatic line for conveying carbonate particles, and a second electrostatic charging device for applying an electrostatic charge to the carbonate particles conveyed in the line that is opposite in polarity to the charge applied to the fuel particles.

Abstract: A mine ventilation structure for installation at the intersection of first and second passageways in a mine. The ventilation structure defines a first passage communicating with the first passageway and a second passage communicating with the second passageway. The ventilation structure includes a pair of generally parallel, spaced-apart side walls defining the side walls of the first passage, and a plurality of elongate deck panels extending between the side walls and forming the roof of one of the first and second passages and the floor of the other of the first and second passages. Each deck panel is a sheet metal panel generally of inverted channel shape in transverse cross section, having an upper web and side flanges extending down from the upper web at opposite sides of the web. Tie bars hold the deck panels together in fixed side-by-side relation with the side flanges of the panels closely adjacent one another so that the webs of the panels form a substantially continuous surface.

Abstract: A structure including at least two generally parallel, spaced-apart side walls, and a plurality of roof panels extending between the side walls for forming the roof of the structure. Each roof panel has opposite ends overlying the upper ends of respective side walls. The roof panels and side wails are constructed with a bayonet connection device for quick connection.

Abstract: A power mine door system including a door frame to be installed in a mine passageway to define a generally rectangular doorway. A mine door is defined by a pair of generally rectangular door leafs which are hinged on the door frame at opposite sides of the doorway for swinging between an open position to permit passage through the doorway and a closed position in which the door leafs are generally coplanar and close the doorway. The door leafs are so dimensioned that there is a substantial vertical gap between the door leafs when they are closed to accommodate convergence of side walls of the passageway. A relatively wide vertical sealing flap is secured to one of the door leafs for overlapping a face of the other door leaf when the door is closed for covering the gap between the door leafs.

Abstract: A mine door system including a door frame to be installed in a mine passageway to define a generally rectangular doorway. A mine door is defined by a pair of generally rectangular door leafs which are hinged on the door frame at opposite sides of the doorway for swinging between an open position to permit passage through the doorway and a closed position in which the door leafs are generally coplanar and close the doorway. The door leafs are so dimensioned that there is a substantial vertical gap between the door leafs when they are closed to accommodate convergence of side walls of the passageway. A relatively wide vertical sealing flap is secured to one of the door leafs for overlapping a face of the other door leaf when the door is closed for covering the gap between the door leafs.

Abstract: A door system for use in a mine stopping comprises a door frame for installation in the stopping to define a doorway, a door hinged to a first side of the door frame for swinging between an open position and a closed position in which the door closes the doorway, and a latch for latching the door in its closed position. The latch comprises a strike which is secured to a second side of the door frame generally opposite the first side and which has a strike plate portion disposed in the doorway in a plane generally perpendicular to the plane of the doorway and spaced from the second side of the door frame thereby to create a void between the strike plate portion and the second side of the doorway. The strike plate portion has a latching aperture therein.

Abstract: A form for making a permanent mine stopping of pourable and hardenable material such as concrete. The form comprises two sets of elongate extension panels, each set including a plurality of panels which may be erected to extend vertically in side-by-side relation from the floor to the roof of a passageway in a mine. When erect, the two sets of panels form two generally vertical walls spaced from one another to define a space to be filled with a pourable and hardenable material to form the stopping. Each panel comprises a pair of elongate sheet metal members having a telescoping sliding fit with one another to permit adjustable extension of the panel to fit the height of the passageway. Tie bars hold the walls of the form in spaced, generally parallel relation prior to, during and immediately after filling of the space between the walls with the pourable and hardenable material.

Abstract: A contractible mine stopping adapted to be installed to extend as a vertical wall from the floor to the roof of a passageway in a mine, comprising a series of rows of substantially solid substantially non-compressible blocks of substantially fire-resistant material stacked one on top of another, and at least one row of contractible substantially fire-resistant block-like members adapted to contract without loss of structural integrity when the wall is subjected to a compressive load, as during a convergence of the floor and roof of the passageway. Each block-like member is preferably a hollow metal member which, when subjected to a compressive load, is adapted to contract heightwise of the member a distance corresponding to at least a major portion of the height of the member without loss of structural integrity of the member.

Abstract: A mine door system adapted for installation and a passageway in a mine, comprising a door frame adapted to be installed in the passageway and defining a doorway spaced below a ceiling of the passageway and mine doors hingedly mounted on the door frame for movement between open and closed positions. The system further comprises a top panel structure for substantially closing the space between the door frame and the ceiling of the passageway, the top panel structure being readily contractible heightwise of the passageway without loss of its structural integrity to accommodate a convergence of the ceiling and floor of the passageway without any substantial heightwise deformation of the door frame.

Abstract: A mine stopping comprising a plurality of panels adapted to extend in side-by-side relation from the floor to the roof of a passageway in a mine. Each panel comprises a first elongate member constituting the lower member of the panel and a second elongate member constituting an upper member of the panel. Each member has a web and flanges at opposite sides of the web, each flange having an inturned portion at its outer edge extending generally parallel to its web. One of the members has a telescoping sliding fit in the other. The upper member of each panel has a head at its upper end, the head being generally of channel shape in transverse cross section having a web and two flanges. A sealing member of compressible material pocketed between the two flanges of the head extends up out of the upper end of the upper member for pressure engagement with the roof.

Abstract: A jack for installing in a mine a plurality of elongate extensible panels adapted to extend vertically in side-by-side relation from the floor to the roof of a passageway in a mine. Each panel comprises a first elongate member consituting a lower member of the panel and a second elongate member constituting an upper member of the panel, each member having a web and flanges at opposite sides of the web, one of the members having a telescoping sliding fit in the other. The upper member of each panel has a head at its upper end and the lower member of each panel has a foot at its lower end.

Abstract: Styrene polymer foam is prepared using a mixed blowing agent of carbon dioxide plus ethyl chloride and optionally a fluorocarbon to provide a foam having primary cells and secondary cells formed in the struts and walls.

Abstract: A mine stopping comprising a plurality of elongate extensible panels extending vertically from the floor to the roof of a passage in a mine. The panels impede the flow of air through the passageway except for a space at a side of the passageway because of irregularity of the side of the passageway. The stopping further has means for impeding the flow of air through the space comprising at least one side extension for the stopping. The side extension comprises a bar and a relatively long and narrow plate secured to the bar with a portion of the bar projecting from one end of the plate constituting its inner end. The extension is mounted on one face of the stopping extending generally horizontally with the plate in a generally vertical plane and extends into the space for blocking it. The projecting portion of the bar lies against the face of the stopping and has means for securing the projecting portion of the bar to the stopping.

Abstract: A door frame and door assembly for installation in a man-door opening in a mine stopping in which the door is hinged for swinging movement on an axis extending transversely across the frame adjacent one face of the frame and adjacent the top of the frame. The hinge also mounts the door for up and down movement of the door relative to the frame. The door is of such height as to occupy a closed position in the frame inclined down from the hinge toward the other face of the frame with its lower edge bearing on the bottom of the frame and with the door at its top being engageable with and extending up past the top of the frame at the one face of the frame. The door is adapted to swing up from its closed position for opening it, and to move relative to the frame at the hinge to avoid jamming and buckling of the door while maintaining closure of the door upon distortion of the frame such as may result from pressure on the frame in a mine stopping.

Abstract: A clamp for use in a mine stopping formed by a plurality of elongate extensible panels extending vertically from the floor to the roof of a passageway in a mine. The stopping comprises a series of main panels extending vertically side-by-side, with a space between two adjacent main panels, and a lap-over panel extending vertically and bridging the space. The clamp comprises a crosshead adapted to fit in the lap-over panel extending laterally of the lap-over panel and a hook-receiving stem slidable on the crosshead lengthwise of the crosshead. The slidable hook-receiving stem is formed to have hooks at the ends of a wire tie hooked thereto with the tie extending around a bar to draw the crosshead via the stem toward lips of the lap-over panel to clamp the latter in place.

Abstract: A mine stopping comprising a plurality of elongate panels adapted to extend vertically in side-by-side relation from the floor to the roof of a passageway in a mine. Each panel comprises a first elongate member constituting the lower member of the panel and second elongate member constituting the upper member of the panel, each member having a web and flanges at opposite sides of the web, one of the members having a telescoping sliding fit in the other. The upper member of each panel has a head at its upper end and a sealing member held in the head extending up out of the upper end of the upper member for engagement with the roof, the head being supported on the panel with the ends of the head spaced from the flanges of the upper member. The lower member of each panel has a foot at its lower end, the foot being secured to the lower panel member with the ends of the foot spaced from the side flanges thereof.

Abstract: A mine stopping comprising a plurality of elongate extensible panels extending vertically from the floor to the roof of a passage in a mine. The panels impede the flow of air through the passageway except for a space at a side of the passageway because of irregularity of the side of the passageway. The stopping further has means for impeding the flow of air through the space comprising at least one side extension for the stopping. The side extension comprises a bar and a relatively long and narrow plate secured to the bar with a portion of the bar projecting from one end of the plate constituting its inner end. The extension is mounted on one face of the stopping extending generally horizontally with the plate in a generally vertical plane and extends into the space for blocking it. The projecting portion of the bar lies against the face of the stopping and has means for securing the projecting portion of the bar to the stopping.

Abstract: A mine door system adapted for installation and a passageway in a mine, comprising a door frame adapted to be installed in the passageway and defining a doorway spaced below a ceiling of the passageway and mine doors hingedly mounted on the door frame for movement between open and closed positions. The system further comprises a top panel structure for substantially closing the space between the door frame and the ceiling of the passageway, the top panel structure being readily contractible heightwise of the passageway without loss of its structural integrity to accommodate a convergence of the ceiling and floor of the passageway without any substantial heightwise deformation of the door frame.

Abstract: A contractible mine stopping adapted to be installed to extend as a vertical wall from the floor to the roof of a passageway in a mine, comprising a series of rows of substantially solid substantially non-compressible blocks of substantially fire-resistant material stacked one on top of another, and at least one row of contractible substantially fire-resistant block-like members adapted to contract without loss of structural integrity when the wall is subjected to a compressive load, as during a convergence of the floor and roof on the passageway. Each block-like member is preferably a hollow metal member which, when subjected to a compressive load, is adapted to contract heightwise of the member a distance corresponding to at least a major portion of the height of the member without loss of structural integrity of the member.