Square embossed roof and rib plate

Abstract

Disclosed is a mine roof and rib support system generally including a square bearing plate. A through hole is positioned near a center portion of the square bearing plate. A peripheral section at least partially circumscribes the bearing plate. In between the through hole and the peripheral section is a rib member area. The rib member area may include two rib members with a convex cross-section connected by a substantially linear surface member disposed between the two rib members, two or more concave ribs with a substantially linear surface member disposed between the two rib members, or two substantially linear surfaces connected by a convex rib member. A safety edge surrounds the square bearing plate. The safety edge may be a rolled edge, a looped edge, a folded edge, or another comparable edge. Also disclosed is a method for making the mine roof and rib support system.

Description

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention generally relates to mine roof and rib supports and, more particularly, to generally square bearing plates used in connection with a mine roof bolt and a primary support member.

[0004] 2. Description of Related Art

[0005] Mine roof and rib (sidewall) control is important for the safety and well being of miners. Surface control is critical to effective roof and rib support systems. Surface control devices with adequate stiffness characteristics can help reduce or even eliminate progressive roof and rib failures. Mine roof and rib controls are typically managed by drilling a bore hole in a mine roof, installing one end of a mine roof bolt in the bore hole, positioning a channel, bearing plate, or mat adjacent to a second end of the mine roof bolt, securing the mine roof bolt in the bore hole, and positioning and tightening the channel plate, bearing plate, or mat to the mine roof or rib strata.

[0006] Channel plates, bearing plates, roof channels, and mats help to further stabilize mine roof or rib strata, which may shift over time and can be a visual indicator that the mine roof bolts have been installed correctly. However, due to the seriousness of the safety issues involved with correctly supporting mine roof and rib strata and the increasing risk of injury caused by mine roof falls, further improvements are desirable.

SUMMARY OF THE INVENTION

[0007] It is an object of the present invention to provide a mine roof and rib control that overcomes the deficiencies in the prior art. It is another object of the present invention to provide a new mine roof and rib control that is economical, in that it reduces the amount of scrap, provides greater strength than current bearing plates, and is also easy and safe to handle, bundle, and install.

[0008] The present invention is directed to a mine roof and rib support system and apparatus and generally includes a square bearing plate, which may be used in conjunction with primary and supplemental roof bolts along with rib support. The square bearing plate defines a through hole positioned near a center portion of the square bearing plate and includes a peripheral section, which at least partially circumscribes the bearing plate. In between the through hole and the peripheral section is a rib member area. The rib member area preferably includes two rib members with a convex cross-section connected by a substantially linear surface member disposed between the two rib members. In a further embodiment of the present invention, the rib member area includes two or more concave ribs with a substantially linear surface member disposed between the two rib members. In a further embodiment of the present invention, the rib member area includes two substantially linear surfaces connected by a convex rib member. The square bearing plate also includes a safety edge where an edge of the peripheral section has been rolled, looped, folded, or otherwise similarly formed.

[0009] These and other advantages of the present invention will be clarified in the detailed description of the preferred embodiments taken together with the attached drawings in which like reference numerals represent like elements throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a top view of a mine roof and rib support system according to the present invention;

[0011] FIG. 2 is a cross-sectional view taken along line 2-2 of the mine roof and rib support system shown in FIG. 1;

[0012] FIG. 3 is a top view of a second embodiment mine roof and rib support system according to the present invention;

[0013] FIG. 4 is a cross-sectional view taken along line 4-4 of a second embodiment of the mine roof and rib support system shown in FIG. 3;

[0014] FIG. 5 is a top view of a third embodiment mine roof and rib support system according to the present invention;

[0015] FIG. 6 is a cross-sectional view taken along line 6-6 of a third embodiment of the mine roof and rib support system shown in FIG. 5;

[0016] FIG. 7 is a top view of a mine roof and rib support system according to the present invention having a safety edge;

[0017] FIG. 8 is a cross-sectional view taken along line 8-8 of the mine roof and rib support system shown in FIG. 7;

[0018] FIG. 9 is a cross-sectional view taken along line 8-8 of a second embodiment of the mine roof and rib support system shown in FIG. 5;

[0019] FIG. 10 is a cross-sectional view taken along line 8-8 of a third embodiment of the mine roof and rib support system shown in FIG. 5;

[0020] FIG. 11 is partial cross-sectional views of alternative safety edges of the mine roof and rib support system shown in FIG. 5;

[0021] FIG. 12 is cross-sectional views of alternative embodiments of rib member areas of a mine roof and rib support system according to the present invention;

[0022] FIG. 13 is a summary chart of tests performed on various embodiments of a mine roof and rib support system of the present invention;

[0023] FIG. 14 is a summary chart of tests performed on various embodiments of a mine roof and rib support system of the present invention and conventional systems;

[0024] FIG. 15 is a flowchart illustration of a method of making a mine roof and rib support system according to the present invention; and

[0025] FIG. 16 is a side view illustration of equipment to form a safety edge on a mine roof and rib support system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] A square bearing plate 10 according to one embodiment of the present invention is shown in FIGS. 1 and 2. The first embodiment square bearing plate 10 is preferably commercial grade steel. The first embodiment square bearing plate 10 generally defines a square shape, a peripheral section 12, and a through hole 16 that is positioned in a center portion of the square bearing plate 10. In this embodiment, the square bearing plate 10 includes a rib member area 18 positioned between the through hole 16 and the peripheral section 12. The rib member area 18 includes two or more rib members 20 with convex cross-sections connected by one or more substantially linear surface member 22 between the two rib members 20. The preferred form of the roof and rib support system has two ribs to provide improved strength and stability.

[0027] A square bearing plate 10 according to a second embodiment of the present invention is shown in FIGS. 3 and 4. In this embodiment, the square bearing plate 10 is similar to the first embodiment square bearing plate 10, with like reference numerals indicating like parts. The second embodiment bearing plate 10 also includes the through hole 16, the peripheral section 12, and two or more rib member areas 18. The rib member area 18 in the second embodiment is different from that in the first embodiment, the rib members 24 are concave instead of convex.

[0028] A square bearing plate 10 according to a third embodiment of the present invention is shown in FIGS. 5 and 6. The third embodiment square bearing plate 10 is similar to both the first and second embodiment square bearing plates 10, with like reference numerals indicating like parts. The third embodiment square bearing plate 10 includes the through hole 16, the peripheral section 12, and the rib member area 18. However, the rib member area 18 in the third embodiment is different from that in the first or second embodiment in that the rib member area 18 includes two or more linear surfaces 28 connected by at least one convex rib member 30.

[0029] FIGS. 7-11 show mine roof and rib support system embodiments forming a safety edge 32 around the peripheral section 12. For example, FIGS. 10 and 11 show ends which are doubled over upon themselves (or folded) 36, looped 38, or otherwise rolled or curled 40, for example, approximately 180 to 360°, toward an inside surface of the plate 10. It has been found that any of these safety edge 32 configurations help to prevent injury from sharp edges, add additional strength to the outer periphery of the plates 10, and also aid in the stacking and destacking of the plates 10.

[0030] FIG. 12 illustrates different possible designs of the rib member area 18 and the resulting calculated moments of inertia. These tests were used to establish the desired first embodiment that provides the greatest possible strength. Using the established preferred design of the rib member area 18, FIG. 11 illustrates a preferred design of the square bearing plate 10 that will provide the greatest strength, yet will allow for a surface area large enough to allow for a 6×6, 8×8, or 6×10 primary support plate, or a substantially similar size elliptical primary support plate to be used in conjunction therewith.

[0031] Any of the aforementioned embodiments are designed to be used with a mine roof bolt to provide mine roof and rib support. Dome-shaped, donut-shaped, flat, or other suitably-shaped mine roof and rib support plates may also be used in conjunction with the square bearing plates 10 according to any of the embodiments of the present invention and a mine roof bolt. The support system may also be used with mine prop supports to increase surface control of the immediate roof surface. Multiple plates may be stacked and used where extra strength is required.

[0032] When used on the roof, the plates 10 assist to prevent various forms of roof collapse. When used on the ribs (sidewalls), the plates 10 assist to prevent rib roll, which is a condition where portions of the rib break out and can endanger the miners. The plates 10 may also be used at track entryways. Because of these various advantages, the system can be used in various mining operations, such as in coal mining with roof bolts (including cable bolts) or in hard rock mining with friction lock devices.

[0033] A test frame set was used to evaluate the performance of the square bearing plates 10 and conventional plates. The test consisted of applying a load to the center of the plate 10. Peak load measurements were measured and recorded during these tests. The load-bearing results are summarized in FIGS. 13 and 14. The results show that the square bearing plate 10 can withstand greater loads than conventional bearing plates with minimal deflection.

[0034] The forming of a square bearing plate 10 of the first or second embodiment from a steel strip or sheet has less scrap per piece, yet will cover more surface area, as compared to conventional round bearing plates. This is considered to be one of the greatest advantages of the present invention, in that it provides greater strength at a cheaper cost based on the reduced amount of scrap per piece.

[0035] Referring to FIGS. 15 and 16, in a method of making a mine roof support system according to the present invention, in a first operation 100, a blank (the square bearing plate 10) is formed from raw material, for example, sheet or strip steel. The blank includes the through hole 16, the peripheral section 12, and the rib member area 18. In a second operation 102, the safety edge 32 is formed around the peripheral section 12 of the blank (square bearing plate 10). The first operation 100 is preferably a one-step operation performed by, for example, a first die assembly.

[0036] Preferably, the second operation 102 is a two-step operation performed by, for example, a second die assembly 104 and a third die assembly 106. First 112, the edge 34 of the peripheral section 12 is deformed to form an angle, for example, of approximately 90°. Second 114, the now angled edge 34 is again deformed to create the safety edge 32. This second deformation can result in a rolled edge, a curled edge, a looped edge, a folded edge, etc.

[0037] The invention has been described with reference to the preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A mine roof support system for a mine roof bolt, comprising: a square bearing plate defining a through hole positioned in a center portion of the square bearing plate and a peripheral section at least partially circumscribing the square bearing plate; and at least one rib member area disposed between the through hole and the peripheral section and at least partially circumscribing the bearing plate, wherein the mine roof bolt is received through the through hole.

2. The mine roof support system according to claim 1, wherein the rib member area includes two or more rib members and one or more substantially linear surface member between each pair of rib members.

3. The mine roof support system according to claim 2, wherein each of the two or more rib members has a convex cross-sectional shape.

4. The mine roof support system according to claim 2, wherein each of the two or more rib members has a concave cross-sectional shape.

5. The mine roof support system according to claim 1, wherein the rib member area includes two or more rib substantially linear surface members and one or more rib member between each pair of linear surface members.

6. The mine roof support system according to claim 5, wherein the rib member has a convex cross-sectional shape.

7. The mine roof support system according to claim 1, further including a safety edge surrounding the peripheral section.

8. The mine roof support system according to claim 7, wherein the safety edge is a rolled edge.

9. The mine roof support system according to claim 7, wherein the safety edge is a looped edge.

10. The mine roof support system according to claim 7, wherein the safety edge is a folded edge.

11. A method of making a mine roof support system, comprising the steps of: a) forming a blank having a through hole positioned in a center portion of the blank, a peripheral section circumscribing the blank, and at least one rib member area circumscribing the blank and disposed between the through hole and the peripheral section; and b) forming a safety edge circumscribing the blank.

12. The method of making a mine roof support system according to claim 11, wherein the step of forming the safety edge includes the steps of: i) forming a substantially 90° angle at an edge of the peripheral section; and ii) subsequently rolling the angle at the edge.

13. The method of making a mine roof support system according to claim 11, wherein the step of forming the safety edge includes the steps of: i) forming a substantially 90° angle at an edge of the peripheral section; and ii) subsequently looping the angle at the edge.

14. The method of making a mine roof support system according to claim 11, wherein the step of forming the safety edge includes the steps of: i) forming a substantially 90° angle at an edge of the peripheral section; and ii) subsequently folding the angle at the edge.

15. The method of making a mine roof support system according to claim 11, wherein the step of forming the blank occurs in a first operation and the step of forming the safety edge occurs in a second operation.

16. The method of making a mine roof support system according to claim 15, wherein the first operation is performed by a first die assembly and the second operation is performed by a second die assembly and a third die assembly.