US 5,344,257 AGranted

Mine roof expansion anchor and bail element

AssigneeThe Eastern Company

InventorsRaymond L. Wright, Carl A. Clark

Life of this patent

Estimating the term…

Loading patent…

Abstract

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.

Claims29

Dependent claims

A bail element formed of a unitary blank of springy sheet metal for maintaining shell and plug portions of a mine roof expansion anchor in assembled relation prior to installation, said bail element comprising:

a) a medial portion of predetermined length having first and second ends;
b) a pair of substantially identical legs extending integrally from respective first junctures with said first and second ends of said medial portion to terminal ends, symmetrically with respect to a centerline through said medial portion, both of said legs lying entirely on one side of a line through said first junctures;
c) each of said legs including integral, first, second and third segments having a configuration in an undeformed condition relative to one another and to said medial portion such that:
i) said first segments extend from said first junctures along respective, first, linear axes to second junctures of said first segments with said second segments;
ii) said second segments extend from said second junctures along respective, second, linear axes to third junctures of said second segments with said third segments;
iii) said third segments extend from said third junctures along respective, third, linear axes to said terminal ends;
iv) said first, second and third axes extending outwardly at respective first, second and third acute angles with respect to said centerline, said first and third angles each being less than about 15.degree. and said second angle being substantially greater than said first and third angles;
and
v) said first segment having a length greater than the combined length of said second and third segments;
vi) said second junctures being spaced a greater distance from said centerline than said first junctures;
vii) said third junctures being spaced a greater distance from said centerline than said second junctures;
viii) said terminal ends being spaced a greater distance from said centerline than said third junctures;
and
d) said medial portion including outer segments extending inwardly from said first junctures along a fourth axis substantially perpendicular to said centerline, a pair of laterally spaced parts extending from said fourth axis in a direction generally opposite the direction in which said legs extend from said first junctures, and a central part extending from said fourth axis in generally the same direction in which said legs extend from said first junctures.

11 more elements

A mine roof expansion anchor assembly comprising:

a) a tapered plug having respective larger and smaller diameter ends, and an internally threaded, through, central bore;
b) a hollow, generally cylindrical shell portion having upper and lower ends and substantially symmetrical about a central, longitudinal axis, said plug smaller end extending into said shell portion upper end, said shell portion further having at least two pairs of fingers extending integrally from base structure at said lower end, said fingers of each pair being separated by open channels;
and
c) a bail element having a centerline substantially coincident with said central axis, a medial portion extending between opposite ends over said larger diameter end of said plug with at least a portion of said medial portion contacting said plug, and a pair of substantially identical legs respectively extending from first junctures with said medial portion opposite ends, down opposite sides of said plug, through said channels on opposite sides of said shell portion and fixedly attached to said base structure, said legs having;
i) first segments extending from said first junctures along respective, first, linear axes inwardly inclined from said first junctures toward said central axis;
ii) second segments extending from second junctures with said first segments along respective, second, linear axes outwardly inclined from said second junctures away from said central axis;
and
iii) third segments extending from third junctures with said second segments along respective, third, linear axes substantially parallel to said central axis, to terminal ends all of said bail element lying within a cylinder defined by the outermost surfaces of said shell portion;
said first junctures being spaced a greater distance from said centerline than said second junctures;
said third junctures being spaced a greater distance from said centerline than said second junctures.

7 more elements

Dependencies are inferred from the claim text.