The Eastern Company

Birmingham Bolt Company

Raymond L Wright

Carl A Clark

Charles W Schaeffer

Roger Giroux

A nut for use with an elongated rod having one end anchored by a hardened resin grouting mix in a drill hole in a mine roof or other such rock formation. The nut has a body portion with a threaded bore through which the rod is advanced and a dome-shaped wall surrounding one end of the bore in radially outwardly spaced relation and an annular lip defining an opening in coaxial, axially spaced relation to the one end of the bore. A metal disc, either solid or with a central opening of smaller diameter than the bore, is positioned in covering relation to the bore and surrounded by the dome-shaped wall. As the rod is advanced through the nut, the disc is moved into contact about its entire periphery with the inside of the dome-shaped wall and rotation of the nut is transmitted to the rod to mix the resin components within the drill hole. After the mix hardens, excess torque applied to the nut deforms the nut toward the dome shape of the wall and eventually fractures the annular lip, thereby expanding the opening and expelling the disc. The torque required to fracture the nut is considerably higher when the disc is incorporated in the nut structure, thereby ensuring complete mixing of the resin components prior to fracture.

Mine roof tension nut having improved frangible qualities

A reinforcing and support system and method of installation thereof including both a mechanical expansion anchor on the distal end of an elongated bolt and a resin grouting mix installed in a blind drill hole in a mine roof, or the like. A pair of elongated leg members, fixed with respect to the shell, extend into the annular space surrounding the bolt below the shell for a distance about as great as the axial length of the shell. Upon advance of the bolt, carrying the expansion anchor and leg members, into the drill hole to break a cartridge containing the initially flowable components of the grouting material, the bolt is rotated to effect expansion of the anchor and tensioning of the bolt. Mixing of the components in the annular space surrounding the bolt below the anchor as the bolt is rotated is enhanced by hydraulic turbulence produced by flow of the components about the leg members. A support nut may be installed on the bolt below the anchor, and the leg members may be fixedly attached to one another near their terminal ends.

Mine roof support system including an expansion anchor with means

A mechanical expansion anchor and radially expansible shell for use therein having particular application in combination with resin grouting materials. The anchor includes a conventional, tapered camming plug moveable axially upon a mine roof bolt to move the shell leaves outwardly into gripping engagement with the drill hole wall. The shell is distinguished by the provision of grooves in the outer surfaces of the shell leaves, extending between the upper and lower ends of the leaves. Components of a resin mix inserted into the drill hole in advance of the expansion anchor, carried on the end of the bolt, flow through the grooves in the outer leaf surfaces to the area below the anchor.

Mine roof expansion anchor, expansible shell element used therein and

The present invention is directed to an anchor assembly for installing a threaded mine-roof bolt under tension in a bore hole formed in underground passageways, mines, and the like. The anchor assembly includes a two compartment resin cartridge and a mechanical expansion unit. A support collar is threaded on the bolt to restrict axial movement of the mechanical expansion unit. The mechanical expansion unit includes a camming plug and an expansion shell. The expansion shell has a plurality of fingers extending upwardly from an annular collar. Spaces or slots are formed between adjacent fingers. Each of the plurality of fingers include a vertically extending rib for forming channels between the external surfaces of the fingers and the side walls of the bore hole to permit the free flow of resin. The side surfaces of the fingers adjacent the uppermost portion thereof are tapered so that substantially V-shaped notches are formed between adjacent fingers. Vertically extending recesses are formed in the camming plug. At least one of the vertically extending recesses of the camming plug is aligned with at least one V-shaped notch formed in the mechanical expansion shell. This arrangement of aligning at least one recess and one V-shaped notch further facilitates the free flow of resin about the anchor assembly components.

Mine roof/bolt anchor assembly and method of installation thereof

A bail element (10) having a medial portion (12) with a pair of legs (14, 16) extending integrally therefrom and a mechanical expansion anchor having a pair of shell halves (68, 70) and tapered plug (80) held in assembled relation by the bail. The bail legs are identical to one another and, prior to assembly with the shell halves and plug, have three distinct, linear portions (46, 48, 50) respectively extending at preferred angles of about 10.degree., 36.degree. and 12.5.degree. with respect to lines parallel to the bail centerline (A--A). The bail medial portion includes a pair of upstanding portions shown in a first embodiment (34, 36) and a second embodiment (54, 56) for puncturing a resin cartridge which may be installed with the anchor.

Mine roof expansion anchor and bail element

A mechanical expansion anchor and tapered plug for use therein having particular application in combination with resin grouting materials. The anchor includes conventional shell structure having a plurality of radially expansible leaves with internal surfaces opposing compression surface portions of a tapered camming plug. Components of a resin mix inserted in a drill hole between the blind end thereof and the end of a bolt carrying the expansion anchor flow around the tapered plug and through axial passageways therein. The plug is distinguished by the provision of axial grooves for passage of resin components in the compression surfaces of the plug.

Mine roof expansion anchor, tapered plug element used therein and method

A threaded fastener and method of fabrication thereof wherein the fastener or nut includes a first portion having external, wrench-engaging surfaces and a central, through bore, internally threaded for at least a portion of its length from a base surface. A wall portion extends integrally from the end of the first portion opposite the base surface, concentrically surrounding and spaced radially outwardly from the end of the bore. The first and wall portions are formed as a metal casting with the wall portion in two segments separated by longitudinally extending, V-shaped notches. The free edges of the wall segments, which initially lie in a plane normal to the axis of the bore, are deformed by a die, moving radially inward so that the wall segments are in a domed configuration with the free edges defining a substantially oval opening having a major axis with a length about equal to the diameter of the bore and a minor axis about 4/5 that of the major axis. A method of supporting a mine roof using such a threaded fastener with a bearing plate, resin cartridge and elongated rod having threads mating with the internal threads of the bore is also disclosed.

Threaded fastener, method of fabrication thereof and method of

A bail member having a medial portion of substantially conical shape for retaining shell and tapered plug portions of a mechanical expansion anchor in mutually assembled relation prior to installation. The medial portion is positioned over the large end of the plug and tapers inwardly in a direction away from the plug to provide a lead-in for insertion of the anchor, carried on the end of a mine roof bolt, into the open end of a blind drill hole. The bolt and medial portion may include an axial bore and a plurality of openings, respectively, for passage of a hardenable grout pumped through the bore to provide an anchoring system of enhance strength and durability.

Mine roof expansion anchor and bail member therefor

An article for assisting in the mixing of components of a resin grouting material within a drill hole in a rock formation to form a hardenable mass anchoring the threaded, distal end of an elongated bolt in the hole. The article includes an annular base portion having a central, through opening for threaded engagement with the bolt, and at least one leg extending from the base portion in a direction substantially parallel to the axis of the opening. The article is rotated together with the bolt, the leg having leading and trailing edges with respect to the direction of rotation. The leading edge is a flat surface substantially parallel to the axis of the bolt and the trailing edge is a relatively sharp, linear edge, non-parallel to the bolt axis. The article may be employed in chemical anchors with a single leg extending from the base portion toward the distal end of the bolt, or with a pair of legs extending in opposite directions from the base portion. In another embodiment, the article is employed in a combination chemical-mechanical anchor with the leg extending away from the distal end of the bolt, upon which the mechanical anchor is mounted with the lower end of the shell contacting and supported by the base portion of the article. Downward force exerted by the shell during expansion strips the threaded engagement of the article with the bolt.

Resin-mixing article for mine roof anchor

A mine roof expansion anchor having a conventional tapered camming plug and radially expansible shell having associated therewith an element which resiliently engages the wall of a bore hole as a roof bolt carrying the anchor is inserted in the hole. The resilient element may be incorporated in the structure of a bail having bore wall engagement portions position in a plane closer to the lower end of the expansion shell than the lowest position of the tapered plug after full expansion. The engagement portions may comprise outwardly and downwardly extending portions of the bail legs, either at the terminal ends or pierced from the bail material slightly above the ends. In another embodiment, the engagement portions extend from a support nut positioned on the bolt below the lower end of the shell.

Mine roof expansion anchor with improved bore hole engagement means and

An otherwise conventional mine roof expansion anchor of the bail-type is provided with a tubular retainer member encircling the shell leaves and having an external cross-dimension significantly (e.g., at least 0.10') greater than the diameter of the drill hole in which the anchor is to be installed. Thus, as the anchor, supported on the end of a roof bolt, is advanced into the drill hole in the usual manner, the tubular element is pushed off the anchor by contact with the surface surrounding the drill hole, thereby eliminating the previously required manual removal of the retainer. The tubular retainer has the same cross-sectional configuration in all planes perpendicular to its central axis throughout its full length, preferably being formed as a plastic extrusion.

Tubular retainer for mine roof expansion anchor and method of use

An expansion shell assembly of the type including a pair of unitary expansion shell elements, each having two leaf members joined adjacent their lower ends by bridge portions with a bail fixedly attached at terminal ends to outer surfaces of the bridge portions to maintain the expansion shell elements in assembled relation. The bridge portions include a recessed area extending continuously between its upper and lower edges. The recessed areas are divided into two portions, with the lower portions substantially narrower than the upper portions, wherein terminal ends of the bail are secured. Opposing edges of the shell elements are in spaced, substantially parallel relation with the space therebetween free of any structure extending into such space over the full axial length of the shell elements. Relieved areas extend into the inner surfaces of the bridge portions to provide a clearance for the lower end of a tapered camming plug which is moved between the shell elements to effect radial expansion thereof.

Mine roof expansion anchor

An assembly and methods of installation thereof for supporting and stabilizing a rock structure adjacent a mine tunnel or other underground passageway. The assembly includes an elongated bolt, threaded from both ends for at least a portion of its length. A conventional, mechanical expansion anchor is threaded on one end of the bolt, within a drill hole in the rock structure, and a bearing plate, washer, jam nut and tensioning nut are carried on the other end, outside the drill hole. The tensioning nut is threaded into firm engagement with the jam nut to prevent further threaded advance of the tensioning nut a substantial distance from the termination of the threads. A torque applied to the tensioning nut thus rotates the bolt and expands the anchor shell into gripping engagement with the bore hole wall; torque producing an axial load on the jam nut in excess of its strength causes it to fracture or strip from threaded engagement with the bolt, permitting travel of the tensioning nut. The jam nut is received in a recess in the lower surface of the washer, which is preferably spherical on its upper surface.

Mine roof support structure and method

An improved, radially expansible shell for use in a mechanical expansion anchor and an anchoring system including such a shell in combination with a resin grouting mix, in a drill hole of predetermined diameter. The shell includes a plurality of leaf portions having internal surfaces for engagement by a tapered camming plug as the shell is expanded, external surfaces having a maximum diameter less than that of the drill hole, and side edges. A row of tapered teeth extends outwardly from the external surface of each leaf along one of the side edges thereof. The distance from the central axis of the shell to the crests of the teeth is substantially equal to the radius of the drill hole. The teeth frictionally engage the drill hole wall to retard rotation of the shell and ensure the desired expansion. When the anchor is used with a conventional, two-compartment resin package, the resin components may flow around the shell into the annular space between the external surfaces of the leaves and the drill hole wall.

Mechanical expansion anchor shell

A one-piece, malleable iron, expansion shell, and a leaf of such shell, for use in an expansion to be installed in a relatively small (about 1') diameter bore hole with a conventional size (5/8') bolt. The expansion shell, and individual shell leaves have unique features contributing to the effectiveness of the anchor when used either with or without a resin grouting mixture. The slots or spaces between adjacent shell leaves include upper and lower portions, each of constant width, the lower portion being wider than the upper portion, whereby the leaves are narrower in the area where they are bent outwardly from the closed ring at the base than in the area where they are compressionally engaged between the plug and the hole wall. Upper portions of the inner leaf surfaces taper toward the shell axis and the side edges of such surfaces taper toward one another from the upper, free ends of the leaves toward the lower ends. A first group of gripping teeth or serrations on the outer leaf surfaces near the lower ends of the leaves are deeper than a second group outwardly adjacent the plug contact area.

Growing community of inventors

Syracuse, NY, United States of America

Raymond L Wright