Joy Manufacturing Company

Ralph C Lumbra

Ward D Morrison

George A Hibbard

An apparatus for bolting the roof of an underground mine is disclosed comprising a mobile frame, a boom extending from the frame and a housing provided at the end of the frame. The housing supports an upwardly extending stinger, a drilling mechanism including a drill centralizer having a central bore therethrough and a passageway in communication with the central bore, a device for delivering a container of roof bolting anchoring media through the passageway and through the drill centralizer and into a drilled hole, a device for indexing a roof bolt into alignment with the drilled hole and a spinner for driving the roof bolt into the drilled hole. The present invention also provides a method for bolting the roof of an underground mine comprising the steps of stinging a housing against the roof of the mine, moving a drill centralizer into communication with the roof and drilling a hole in the roof. Without retracting the drill centralizer from communication with the roof, a container of roof bolt anchoring media is delivered through the centralizer and into the drilled hole. The drill centralizer is thereafter retracted and the housing is moved to align a roof bolt with a drilled hole. Then the roof bolt is driven into the drilled hole and the bolt anchoring media sets around the bolt.

Mine roof driller-bolter apparatus and method

A method and apparatus for maintaining alignment of the drill steel or drill rod of a drilling machine in which a midpoint centralizer or indicator ring having an aperture therethrough substantially greater than the diameter of the drill rod or drill steel is used like a rifle sight to indicate the nature and degree of misalignment so that adjustments can be made in the operating mechanisms of the drilling machine or the support and positioning mechanisms for the drilling machine to remove the cause of the misalignment and to return the drill steel to its centered, aligned position in the indicator ring. In normal operation the drill steel does not contact the indicator ring so that noise transmission and frictional losses normally associated with midpoint centralizers is avoided. Mechanical contact between the drill steel and indicator ring occurs only to limit the maximum deflection and maximum stress which will occur in the drill steel due to bending. Guided by the indications at the indicator ring a skilled operator can greatly reduce or substantially avoid the occasions when mechanical contact actually occurs.

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Claremont, NH, United States of America

Ralph C Lumbra