Friction stabilizer with tabs
A friction stabilizer having tabs comprising a tubular body comprising an exterior surface and having a first portion and having a second portion provided with a taper. The first portion has an impact end and the second portion has an insertion end. A tab is on the tubular body and extends outward from the exterior surface of the tubular body in a direction toward the impact end and away from the insertion end of the tubular body. The tabs can be rectangular shaped or triangular shaped or have other shapes which prevent the friction stabilizer from being removed from a drilled bore in a mine. When the friction stabilizer with tabs is inserted into a drilled bore in a mine, the tabs do not impede insertion. But, after insertion into the drilled bore the tabs resist removal of the tubular body, and thus allow the stabilizer to support the mine wall or ceiling. The friction stabilizer is made by taking a steel coil and punching the shape of the tabs in the metal, for example sheet metal, unrolled from the coil. A notch is also punched into the sheet at a predetermined location. Rolling die roll the tubular body, and a cutting machine cuts the tubular body at the notches, so tubular bodies of predetermined length are cut. The tabs extend from the exterior surface of the tubular body due to the natural spring constant of the steel or metal from which the tubular body is made. A weld ring is welded to the impact end and has a weld ring gap space.
This application is a divisional of U.S. patent application Ser. No. 10/946,468 to Valgora, filed on Sep. 21, 2004 for a “Friction Stabilizer With Tabs” which claims the benefit of U.S. Provisional Patent Application No. 60/507,366 to Valgora, filed on Sep. 30, 2003, for a “Friction Stabilizer With Tabs.”
BACKGROUNDCave-ins are a constant threat associated with underground mining operations. It is difficult to predict when and where a cave-in will occur. Typically, workers are provided with little or no warning prior to a cave-in, and thus they have a minimal amount of time to react to a cave-in. Indeed, mine walls or ceilings that appear fine upon visual inspection may have significant fractures just below their surfaces, making them structurally weak and prone to collapse. Cave-ins are very destructive and may result in miners becoming trapped and/or injured. Additionally, equipment and machinery may be damaged or destroyed.
Friction type stabilizers have been used in mining operations to stabilize walls and ceilings of the mine. Such stabilizers are pounded into bores drilled in mine walls and ceilings. The stabilizers form a friction fit with the drilled bore. But, these stabilizers may slide out of the drilled bores when the rock wall or ceiling shifts/moves, and in such situations the stabilizers are unable to prevent a mine wall or ceiling cave-in.
Therefore, it would be desirable to provide a new and improved stabilizer that decreases the likelihood of a cave-in. It would also be desirable if the stabilizer was compatible with existing mining equipment and inexpensive to fabricate.
SUMMARYThe friction stabilizer with tabs according to this invention is used to secure the walls and ceilings of mines to thus prevent a cave-in from occurring. The friction stabilizer with tabs comprises a hollow body, preferably tubular. The tubular body comprises an impact end, an insertion end, a first portion and a second portion. The second portion has a notch and is tapered.
The tubular body has an interior and an exterior surface, and tabs are connected to and extend from the tubular body. The tabs extend in a direction leading away from the insertion end of the tubular body and in a direction leading towards the impact end of the tubular body. The tabs each make an acute angle with the exterior surface of the tubular body. The tabs can be rectangular shaped and there can be three such tabs extending from the exterior surface of the tubular body. Each rectangular shaped tab further comprises parallel tab side edges and a tab free edge connecting between the tab side edges.
In other embodiments, the tabs may be triangular shaped tabs, curved shaped tabs, polygonal shaped tabs, U-shaped tabs, tabs having both curved portions and linear portions, semi-circular shaped tabs, hook shaped tabs, parabolic shaped tabs, and combinations of the above. Also, the tabs can be of any shape that inhibits the withdrawal of the friction stabilizer with tabs from the drilled bore in a mine. The above-described tabs are punched into the sheet from which the tubular body is formed by a punching machine, thus they are joined to the tubular body at bends.
The tubular body further comprises a first gap space wall and a second gap space wall spaced apart from one another by a tube gap space. The tube gap space is used for allowing the tubular body to be compressed radially inward when the tubular body is driven into a drilled bore in a mine having, the drilled bore having a diameter less than the outer diameter of the tubular body.
The friction stabilizer further comprises a weld ring having a weld ring gap space, and the weld ring is joined to the tubular body such that the weld ring gap space and tube gap space are aligned. The weld ring is joined to the exterior surface of the first portion of the tubular body at the impact end of the tubular body by, for example, a weld. The weld ring gap space is used for allowing the weld ring to be compressed radially inward. The weld ring can have a rectangular cross section or a circular cross section.
To use the friction stabilizer with tabs, a drilled bore is made in the wall or ceiling of the mine. The wall is sufficiently solid and of sufficient thickness to accommodate a bore of sufficient length, and the drilled bore has a diameter slightly less than the diameter of the tubular body. A support plate having an opening is provided, the opening being sized such that the tubular body can pass through the opening. The opening in the plate is aligned with the drilled bore. The tapered end of the tubular body is aligned with and inserted through the opening in the plate and into the drilled bore so that the taper of the tubular body is received in the drilled bore.
Then a pneumatic or hydraulic hammer or some other means for hammering is used for pounding or driving the stabilizer with tabs into the drilled bore. As the stabilizer with tabs is driven into the drilled bore the tabs move or flex inwardly towards the exterior surface of the tubular body. This allows the friction stabilizer with tabs to be hammered into the drilled bore without the tabs impeding movement. During the pounding process the plate becomes trapped between the weld ring and the surrounding ceiling or wall of the mine, as the case may be. Additionally, the tubular body compresses and the gap space distance decreases as the friction stabilizer is driven into the drilled bore. Then, if loading force is applied to remove the tubular body with tabs, the tabs immediately dig into the surrounding wall which surrounds the drilled bore, making the removal of the tubular body significantly more difficult. Such loading force may come from the plate that is providing support. Thus, if the ceiling or wall begins to cave-in, the tabs will keep digging into the surrounding wall, and the friction stabilizer having tabs continues to work against a cave-in. This digging-in action could stop a cave-in in progress or limit the severity of a cave-in. Additionally, the digging-in action could provide miners with extra time to get out of harms way, or provide inspectors with time so that they can conduct an on site inspection.
BRIEF DESCRIPTION OF THE FIGURES
At the outset, it noted that like reference numbers are intended to identify the same structure, portions, or surfaces consistently throughout the figures. It is also noted that when the term “about” is used in connection with describing a number that the number includes numbers in decimal form that can be rounded to that number.
Shown generally in
The tubular body 22 further comprises an interior surface 24 and an exterior surface 26, as shown in
As further shown in
A notch 36 is defined in the taper 35 of the second portion 34 of the tubular body 22. The notch 36 allows the taper 35 to be formed in the tubular body 22 at the insertion end 32 thereof when the tubular body 22 is being rolled. The taper 35 is used for allowing the insertion end 32 of the tubular body 22 to be initially fitted or inserted into the drilled bore 50. After the taper 35 is fitted into the drilled bore 50, the impact end 30 of the tubular body 22 can be pounded causing the tubular body 22 to move into the drilled bore 50.
In accordance with the invention, the tubular body 20 comprises tabs 25 that extend from the exterior surface 26 in a direction toward the impact end 30 of the tubular body 20, and away from the insertion end 32 of the tubular body 22. The tabs 25 work against the removal of the tubular body 22 from a drilled bore 50 in a mine 56. As a result, the tabs 25 advantageously decrease the likelihood of a mine 56 cave-in, as will be described presently.
In a preferred embodiment, the tabs 25 are embodied to be rectangular shaped tabs 40. In particular, there is a first rectangular shaped tab 40a, a second rectangular shaped tab 40b, and a third rectangular shaped tab 40c. The first rectangular shaped tab 40 is positioned closest to the insertion end 32 of the tubular body 22, and the third rectangular shaped tab 40c is positioned farthest from the insertion end 32 of the tubular body 22, as shown in
The first, second, and third rectangular shaped tabs 40a, 40b, and 40c, respectively, extend outward from the exterior surface 26 of the tubular body 22. Each rectangular shaped tab 40a, 40b, 40c comprises two parallel tab side edges 43 and a tab free edge 45 that extends between the tab side edges 43, as shown in
Each of the rectangular shaped tabs 40a, 40b, and 40c, respectively, is joined to the tubular body 22 along a bend 44, with the bend being opposite the tab free edge 45. The bends 44 are closer to the insertion end 32 of the tubular body 22 than the tab free edge 45. Each of the rectangular shaped tabs 40a, 40b, and 40c, respectively, makes an acute angle with the exterior surface 26 of the tubular body 22, as shown in
Then, when the tubular body 22 is pounded into a drilled bore 50 insertion end 32 first, the rectangular shaped tabs 40a, 40b, and 40c, respectively, bend inward along their bends 44 in a direction toward the openings 48 in the tubular body 22. In other words, the rectangular shaped tabs 40a, 40b, and 40c, respectively, move back into the tubular body 22 from which they were punched, and thus they do not impede the tubular body 22 from being pounded into the drilled bore 50 in the wall 52 or ceiling 54 of the mine 56, as shown in
The three rectangular shaped tabs 40a, 40b, and 40c, respectively, are spaced along a tubular body 22 about sixty inches long such that the first tab 40a is about four inches from the insertion end 32 of the tubular body 22, the second tab 40b is about fourteen inches from the insertion end 32 of the tubular body 22, and the third tab 40c is about twenty-four inches from the insertion end 32 of the tubular body 22. The rectangular shaped tabs 40a, 40b, and 40c, respectively, can be sized such that the tab side edges 43 are about 0.5 inches long, and the tab free edge 45 is about 1.0 inch. The rectangular shaped tabs 40a, 40b, and 40c, respectively, advantageously provide for a stabilizer 20 that, when installed in a mine, can support greater loads than stabilizers having smooth exterior surfaces. Of course, the dimensions may differ in other embodiments.
The friction stabilizer 20 further includes a weld ring 31 that in one embodiment is rectangular shaped, that is, its cross section is rectangular shaped as shown in
It is noted that a circular shaped weld ring 37 having a circular shaped cross section, as shown in
The rectangular shaped weld ring 31 shown in
The above-described invention can be variously embodied.
Shown in
To manufacture the friction stabilizer with tabs 20, reference is made to the schematic shown in
As the strip of steel 102 is pulled from the coil 100, it moves onto a conveyor 105. The strip of steel 102 passes through a pressing machine 104 wherein the tab side edges 43 and tab free edges 45 are pressed into the flat strip of steel 102. Pressing machines are well known to those having ordinary skill in the art. It is to be understood that the tab side edges 43 and free edges 45 may also be laser cut or otherwise formed in the sheet of steel 102 at this point in the manufacturing process, by the use of a laser or other device. The shape of the tab 25 is thus formed in the sheet of steel 102. It is to be further understood that any desired shape of the tab 25 could be formed by the pressing machine 104.
The strip 102 is next moved by conveyor 105 through a punching machine 106 where the notches 36 are punched out of or otherwise formed into the flat strip 102. Punching machines 106 are known to those having ordinary skill in the art. In another embodiment, the notches 36 could be punched from the strip 102 first, and then the tabs 40 pressed in the strip 102.
A means for measuring 108 continuously measures the length of the strip 102 prior to the punching machine 106 so that the notch 36 can be punched in the strip 102 at the desired position in the strip 102. The final length of the friction stabilizer with tabs 20 is thus determined by the notch 36 location in the strip 102. Next, the strip 102 passes from the punching machine 106 and is moved by conveyor 105 through a cold roll forming mill 110. The cold roll forming mill 110 comprises a series of stands having top and bottom rolling die 112a, 112b, respectively. Cold roll forming mills 110 are known to those having ordinary skill in the art.
As the strip 102 progresses from stand to stand in the cold rolling mill 110 it is formed into a tubular body 22 having the above-described tube gap space 28. At the same time, the rectangular shaped tabs 40 begin to move away from the exterior surface 26 of the continuous tubular body 22z that is being formed in the cold rolling mill 110. This is attributed to the fact that the natural spring constant of the steel, steel alloy, galvanized steel, or other metal from which the continuous tubular body 22z, is made causes the rectangular shaped tabs 40 to extend from the exterior surface 26 thereof. It is noted that if the tabs do not extend out, then they may be mechanically pushed out of the tubular body 22.
As the continuous tubular body 22z exits the cold roll forming mill 110, the tabs 40 extend from it as previously described and it has notches 36, but still has to be cut to the predetermined length. The continuous tubular body 22z is then moved by conveyor 105 through a cut-off press 114, where the notch 36 in the tubular body 22 signals the cut-off press 114 to cut the tubular body 22 to the predetermined length at the notch 36. The length of the tubular body may be about 60 inches as shown in
The tubular body 22 is then placed on conveyor 105 and transported to a swaging station 116. At the swaging station 116, the insertion end 32 of the tubular body 22, where the notch 36 is located, has pressure applied to it such that the taper 35 is formed at the insertion end 32. It is noted that the notch 36 provides the space for the taper 35 to be formed in the section portion 34 in the swaging station 116.
The tubular body 22 is then moved by a conveyor 105 to a welding station 118. At the welding station 118 the rectangular shaped weld ring 38 is fitted about the impact end 30 of the tubular body 22, such that the weld ring gap space 39 aligns with the tube gap space 28. While held in this position by the welding machine, the tubular body 22 and weld ring 38 are welded together, and thus joined by a weld 49. Welding stations 118 are well known to those having ordinary skill in that art. After welding, the weld ring 38 is joined with the impact end 30 of the tubular body 22. The weld ring gap space 39 may be laser cut or punched out of the weld ring 38.
After exiting the welding station 118, the tubular bodies 22 are moved by conveyor 105 to a packing station 120 having an automatic packaging machine 121. Every other tubular body 22 is then turned end over end and automatically packaged in bundles 122 of, for example, six tubular bodies 22, by the automatic packaging machine 121. Automatic packaging machines 121 are known to those having ordinary skill in the art. The bundles 122 are transported by conveyor 105 to a shipping station 124, placed in crates 126, and shipped.
After the friction stabilizer with tabs 20 has been rolled and formed as described above, the tabs 40 may have sharp tab side edges 43 and tab free edges 45. Thus, another step that may be included in the process or method is a grinding step, which takes place prior to automatic packing of the tubular bodies 22. During the grinding step, any sharp tab side edges 43 and tab free edges 45 are ground down and dulled, thus decreasing the likelihood of a worker being cut or injured by the tabs 40.
The same general method or process is carried out to make the other embodiments of the friction stabilizer having tabs 20, described above. For each embodiment the pressing machine 104 would stamp, punch, or cut edges in the strip of steel 102 such that the tab 25 of desired shape may be formed (rectangular shaped tabs, triangular shaped tabs, curved shaped tabs, polygonal shaped tabs, U-shaped tabs, tabs having both curved portions and linear portions, semi-circular shaped tabs, hook shaped tabs, parabolic shaped tabs, combinations of the above, or any other shaped tab that inhibits the withdrawal of the friction stabilizer with tabs 20 from the drilled bore 50 in the mine 56).
To use the friction stabilizer 20 with tabs, a drilled bore 50 is made in a wall 52 or ceiling 54 of a mine 56 having a floor 55, as shown in
As shown in
To accomplish this, the impact end 30 of the tubular body 22 is driven by a pneumatic hammer, hydraulic hammer, or other means for hammering or driving (not shown) into the drilled bore 50. The tubular body 22 compresses radially inward as it is driven into the drilled bore 50, such that the tube gap space 28 decreases. Additionally, the tabs 40 fold in a direction toward the exterior surface 26 of the tubular body 22, and do not resist insertion of the tubular body 22 into the drilled bore 50. As a result of tubular body 22 being driven into the lesser diameter drilled bore 50, the tubular body compresses radially inward and the tube gap space 28 and weld ring gap space 39 both decrease. The tubular body 50 then exerts expanding forces against the adjacent surrounding drilled bore wall 51.
Also, in another embodiment shown in
It is noted that as the stabilizer 20 with tabs is driven into the drilled bore 50, the rectangular shaped tabs 40 move downwardly toward the tubular body 22 and do not obstruct insertion into the drilled bore 50. However, once driven into the drilled bore 50, the tabs 40 force outwardly from the tubular body 22 due to the natural spring constant of the steel or other material from which the stabilizer with tabs 20 is made. The tabs 40 contact the adjacent surrounding drilled bore wall 51 and dig into it, resulting in the friction stabilizer with tabs 20 being held in the drilled bore 50 by both a friction fit created by the expanding forces generated by the tubular body 22, and by the tabs 40 digging into the drilled bore 50.
Then, if force is applied to remove the friction stabilizer with tabs 20, the tabs 40 immediately dig into the adjacent drilled bore wall 51 and work against removal of the stabilizer with tabs 20 from the drilled bore 50. This significantly reduces the likelihood that the stabilizer with tabs 20 will work its way out of the drilled bore 50 and advantageously significantly increases the amount of weight or force the friction stabilizer with tabs 20 can support. Thus the friction stabilizer with tabs 20 advantageously decreases the likelihood of a cave-in of walls 52 and/or ceilings 54 of a mine 56.
In addition, the plate 58, which is trapped between the weld ring 38 and mine wall 52 or ceiling 54 after installation, provides for-additional support of the surrounding mine walls 52 and ceilings 54, as the case may be. It is noted that the plate 58 is supported by the weld ring 38. Thus, if the rock above the plate 58 fractures and weakens, the plate 58 supports the rock, and the plate 58 in turn is supported by the friction stabilizer with tabs 20 in the drilled bore 50, and the tabs 40 advantageously constantly working against removal of the friction stabilizer with tabs 20 from the drilled bore 51.
The present invention also provided for a mine support system 80. In particular, the friction stabilizer 20 having tabs can be positioned and spaced from one another in drilled bores 50 that are spaced about three feet apart from one another in all directions, for example in the walls 52 and ceiling 54 of the mine 56. A wire mesh 65 is provided. The wire mesh 65 is positioned adjacent to the walls 52 and ceiling 54 of the mine 56. Then the plates 58 are aligned with the drilled bores 50 in the manner described above. Next, the friction stabilizer 20 is driven into the drilled bore 50 in the manner previously described. The wire mesh 65 extends between all of the plates 58 in the mine and is trapped between the plates 58 and the mine wall 52 and plates 58 and ceiling 54. The wire mesh 65 serves to support any rocks or debris that break off of the walls 52 or ceiling 54 of the mine 56. The ability of the wire mesh 65 to support greater loads is advantageously increased, because the friction stabilizer having tabs 40 can support a greater load from the wire mesh 65. Thus, the stabilizer with tabs 20 can be used as an integral part of a mine support system 80 to prevent mine 56 cave-ins.
It is noted that the above-described support system 80 can be used in combination with any of the above-described-embodiments of the friction stabilizer having tabs 20.
As previously described, in other embodiments the tabs 25 can be any of a plurality of different shapes (rectangular shaped tabs, triangular shaped tabs, curved shaped tabs, polygonal shaped tabs, U-shaped tabs, tabs having both curved portions and linear portions, semi-circular shaped tabs, hook shaped tabs, parabolic shaped tabs, combinations of the above, or any other shaped tab that inhibits the withdrawal of the friction stabilizer with tabs 20 from the drilled bore 50 in the mine 56).
Additionally, in other embodiments, the rectangular shaped tabs 40 can be formed such that they extend from the tubular body 22 anywhere from the exterior surface 26 of the tubular body 22 including randomly or in patterns. The same is true with respect to all of the above-described differently shaped tabs 25, in that they may all extend from the tubular body 22 randomly or in patterns. Also, the number of tabs 25 can be varied regardless of the shape of the tab 25. In addition, the size of the tab 25 can be varied depending on the requirements of the particular application in which the stabilizer 20 will be deployed. In yet other embodiments a single tab 25 having any of the above described shapes may extend from the tubular body 22. Also, in other embodiments the length of the taper 35 of the second portion 34 may be increased or decreased.
Also, the diameter of the tubular body 22 of the friction stabilizer with tabs 20 may be more or less than an inch, but in other embodiments the diameter of the stabilizer may be customized to suit particular needs for a particular application. The tubular body 22 can comprise various lengths L, for example the sixty inch length described above, or a length required for a particular application. For example, some mines 56 may require tubular bodies 22 having lengths of twelve, eighteen, or forty inches, whereas other mines 56 may require tubular bodies 22 having lengths of over two hundred inches. The friction stabilizer having tabs 20 may be used in these mining applications. The material from which the stabilizer 20 and weld ring 38 are made comprises metal, such as steel, steel alloys, galvanized steel, high strength steel, metal and metal alloys.
Although a friction stabilizer 20 with tabs has been described, the present invention could be otherwise embodied without departing from the principles thereof, and all such embodiments come with the scope and sprit of the present invention for a friction stabilizer 20 having tabs.
Claims
1. A method of making a friction stabilizer for installation in a structural body, the method comprising the steps of:
- providing a coil of metal and unrolling the coil of metal into a strip,
- pressing the shapes of a tab to be formed into the strip of metal,
- moving the strip of metal through cold rolling dies and forming the strip of steel into a tubular body having an exterior surface and a first portion and a second portion having a taper.
2. The method of making a friction stabilizer according to claim 1 wherein the step of pressing the shape of the tab to be formed includes pressing a rectangular shape into the strip of metal.
3. The method of making a friction stabilizer according to claim 1 wherein the step of pressing the shape of the tab to be formed includes pressing a triangular shape into the strip of metal.
4. The method of making a friction stabilizer according to claim 1 wherein the step of pressing the shape of the tab to be formed includes pressing a polygonal shape into the strip of metal.
5. The method of making a friction stabilizer according to claim 1 wherein the step of pressing the shape of the tab to be formed includes the step of pressing a curved shaped tab into the sheet of metal.
6. The method of making a friction stabilizer according to claim 1 wherein the step of pressing the shape of the tab to be formed includes the step of pressing a plurality of shapes of tabs to be formed into the tubular body.
7. The method of making a friction stabilizer according to claim 1 comprising the further steps of forming the tubular body to have a tubular body gap space and providing the weld ring with a weld ring gap space and aligning the tubular body gap space and weld ring gap space before connecting the weld ring to the exterior surface of the first portion.
8. The method of making a friction stabilizer according to claim 1 comprising the further step of punching a notch in the strip of metal.
9. The method of making a friction stabilizer according to claim 8 comprising the further step of using the notch for cutting the tubular body at a predetermined length such that the tubular body has an insertion end having the notch and an impact end opposite the insertion end.
10. The method of making a friction stabilizer according to claim 9 comprising the further step of swaging the insertion end of the tubular body and to form the taper in the tubular body.
11. The method of making a friction stabilizer according to claim 1 comprising the further step of providing a weld ring and joining the weld ring to the exterior surface of first portion.
Type: Application
Filed: Mar 4, 2005
Publication Date: Jul 7, 2005
Inventor: George Valgora (Oakville)
Application Number: 11/072,390