Patent Application
20060086885
1. Field of the Invention
The present invention relates generally to a pressurized liquid, load-bearing structure. More particularly, the present invention relates to column with a longitudinally expandable sleeve to contain a pressurized liquid.
2. Related Art
In mining it is often necessary to support the ceilings of tunnels and cavities to resist collapse. Various different methods have been proposed to prevent ceiling collapse. Traditional methods include wood or steel structures forming a framework to support the ceiling. Such wood or steel structures often become permanent due to the difficulty of removing them. In addition, the transportation of the necessary materials into the mine, and the construction of the framework, is often difficult and time consuming. Cement structures also have been proposed, but are difficult to use because the concrete must cure before accepting loads. In addition, unexpected loads can crush and destroy the forms before the concrete cures.
It has been recognized that it would be advantageous to develop an improved method and apparatus for supporting loads, such as ceilings in a mine. In addition, it has been recognized that it would be advantageous to develop an expandable and/or collapsible load bearing structure capable of being collapsible for transportation, and expandable for use.
The invention provides a load-bearing, pressurized-fluid column apparatus for supporting a load with respect to a support surface. An elongated, flexible sleeve and a bladder retain a substantially incompressible liquid. The elongated, flexible sleeve has at least two configurations, including a collapsed and an expanded or rigid configuration. In the collapsed configuration, the bladder is not filled, and has a first, shorter length. In the expanded or rigid configuration, the bladder is filled with the liquid, and has a second, longer length sized to extend to and between the load and the support surface. The incompressible liquid is capable of transferring a compressive force of the load to tension load in the sleeve. A valve allows the liquid to be added to the sleeve, and prevents escape of the liquid.
In accordance with a more detailed aspect of the present invention, the sleeve can include two sleeve portions telescopically engaging one another.
In accordance with another more detailed aspect of the present invention, the sleeve can include a flexible, high strength woven fabric to withstand high-tension loads, and the bladder can include a flexible, liquid impervious layer to contain liquid.
In accordance with another more detailed aspect of the present invention, the sleeve has a circular, cylindrical shape in the expanded configuration to withstand tension loads.
In accordance with another more detailed aspect of the present invention, the apparatus further includes a base to abut the support surface, and a cap to abut the load. The sleeve has opposite ends, one end being coupled to the base and the other end being coupled to the cap to form an enclosure to extend to and between the load and the support surface in the expanded configuration.
In accordance with another more detailed aspect of the present invention, at least one of the ends of the sleeves is adjustably coupled to either the cap or the base to selectively adjust the length of the sleeve, and the distance between the cap and the base. A ring can be securable to either the cap or the base. One end of the sleeve can be wrapped around the ring and selectively slid around the ring to adjust the length of the sleeve, and the distance between the cap and the base.
In accordance with another more detailed aspect of the present invention, the apparatus can further include means for limiting longitudinal extension of the sleeve. For example, cables or rods extending between the base and the cap can be used.
In accordance with another more detailed aspect of the present invention, the base and cap can include inner and outer plates with a ring disposed in an annular groove. The ends of the sleeve can extend between the plates and around the ring to retain the ends of the sleeves between the plates.
A method for utilizing the column apparatus for supporting a load with respect to a support surface includes positioning a flexible sleeve and/or bladder in a desired location between the load and the support surface. A substantially incompressible liquid is introduced into the sleeve and bladder to lengthen the sleeve to a length extending to and between the load and the support surface. Escape of the liquid from the sleeve is prevented so that the volume of the sleeve between the load and the support surface is maintained at a substantially constant value so as to resist movement of the load towards the support surface.
In accordance with another more detailed aspect of the present invention, the liquid in the sleeve or bladder can be pressurized.
In accordance with another more detailed aspect of the present invention, the step of introducing a liquid into the sleeve further includes opening a valve. Likewise, the step of preventing escape of the liquid includes closing the valve.
In accordance with another more detailed aspect of the present invention, the step of positioning a sleeve further includes positioning a first plate to abut the support surface. A first end of the sleeve is secured to the first plate so that the first plate seals the first end of the sleeve. A second end of the sleeve is secured to a second plate so that the second plate seals the second end of the sleeve. The second plate is positioned to abut the load.
In accordance with another more detailed aspect of the present invention, the length of the sleeve is adjusted to extend to and between the load and the support surface. An end of the sleeve can be wrapped around a ring.
Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.
a is a partial cross-sectional view of the column apparatus of
b is a partial cross-sectional view of the column apparatus of
Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.
As illustrated in
The column apparatus 10 extends between the load 14 and support surface 18 to resist relative movement between the load 14 and the support surface 18, or to resist displacement of the load 14 towards the support surface 18. A first or base end of the column apparatus 10 abuts the support surface 18 or ground, while a second or cap end abuts the load 14 or ceiling. Thus, the column apparatus 10 can support the load 14 or the ceiling of the mine.
The column apparatus 10 includes a flexible sleeve 22 that retains an incompressible liquid 26. In one aspect, the incompressible liquid 26 can be pressurized and can fill the sleeve 22. While either the liquid or the flexible sleeve alone are incapable of providing support due to their respective liquid or flexible nature, the sleeve 22 with the liquid 26 contained therein together form a rigid column capable of resisting an applied load.
The flexible sleeve 22 advantageously has at least two configurations, including a first collapsed, unused, and/or transportable configuration, as shown in
Referring to
In one aspect, the flexible sleeve 22 is formed of a flexible and high-strength material configured to withstand high-tension loads. The material can include a woven fabric material with threads of high tension strength. The sleeve 22 can be formed by wrapping a sheet of the material into a sleeve or cylindrical shape. The sheet can be attached to itself, or edges thereof can be attached, to retain the shape. For example, the sheet or the edges can be attached by an adhesive. In one aspect, the sleeve 22 can include a plurality of layers of the material. For example, the sleeve 22 can be formed by wrapping a single continuous sheet of the material around itself one or more times to form the multiple layers. The multiple layers of material bear against one another and provide a frictional force that resists unwrapping of the sheet. In addition, the sheet or edge thereof can be attached to itself to resist unwrapping. In one aspect, the sleeve 22 has a circular cylindrical shape in the second, load-bearing configuration to evenly distribute pressure in the sleeve 22, and to provide hoop-stress circumferentially around the sleeve 22, as discussed below. In addition, the sleeve 22 can be formed as a continuous weave so that there is no seem.
In addition, the sleeve 22 or material forming the sleeve can be liquid resistant or liquid impervious. Referring to
As described above, the liquid 26 is substantially incompressible. The liquid 26 can be, for example, water or the like. Water is preferred as mines typically have a source or pressurized water. It is believed that incompressible liquids, such as water, are preferable to compressible fluids or gases, such as air, for safety reasons. It is believed that any unintentional puncture or rupture of the column apparatus will be less violent, or have less energy, with water than with a compressed gas. Additives or chemicals can be added to the water to resist corrosion, leakage, etc.
Referring again to
The base 38 and the cap 42 can have plates 46 and 50 to bear against the support surface 18 and load 14. In one aspect the plates 46 and 50 are substantially planer or flat. As stated above, the sleeve 22 can be circular. Thus, the base 38 and the cap 42 can have circular receptacles to receive the ends of the sleeve 22 therein. The receptacles can include an outer annular wall or rim 54 extending from the plate 46 or 50 into which the sleeve 22 is received. The base 38 and the cap 42, or the plates 46 and 50, provide stability to the sleeve 22.
Referring now to
In addition, an inner annular wall 60 can extend from the plate 50, forming an annular gap 64 or slot between itself and the outer annular wall 54. The gap 64 can be sized to produce an interference fit with the ring 58 and sleeve 22 folded thereabout. One or more apertures 68 can be formed in the inner annular wall 60 to allow the pressure of the fluid to act upon the ring 58 and sleeve 22. The inner annular wall 60 can extend a greater distance beyond the outer annular wall 54. Thus, an annular fastener 72 can be tightened around the sleeve 22 and an extended portion of the inner annular wall 60 to secure the sleeve 22 to the wall 60 during lower pressure. The annular fastener 72 can be an elastic cord, an adjustable ring, etc.
Referring to
It is of course understood that on or both ends of the sleeve 22 can be fixedly attached to the cap 14 and the base 18, as described above and illustrated in
Referring again to
Referring to
Referring again to
Referring again to
It will be appreciated that the load 14 exerts a load force, indicated by arrow 108, substantially along the longitudinal axis of the column apparatus 10 or sleeve 22. The liquid 26 in the sleeve 22 can be pressurized, thus exerting a column force, indicated by arrows 112, outwardly on the sleeve 22 and the base and cap 38 and 42, or plates 46 and 50 thereof. The liquid 26 can be pressurized from a liquid source that is also pressurized, and/or the force 108 from the load also can act to pressurize the liquid 26. The column force 112 and/or pressure exerted on the sleeve 22 causes hoop-strain in the sleeve or material thereof, and causes the sleeve 22 to become rigid. In addition, the column force 112 acts against the load force 108 from the load 14.
It also will be appreciated that the magnitude of the column force 112 to resist the load force 108 will depend on the configuration of the column apparatus 10 and the pressure of the liquid 26. For example, the column force will be equal to the pressure of the fluid 26 over the area, such as the plate 50, which the pressure acts, or F=PA. Therefore, the column apparatus 10, or sleeve 22, cap 42 or plate 50, can be sized, and the pressure of the liquid 26 deter-mined, to resist an anticipated load force 108. It is anticipated that such a column apparatus 10 or sleeve 22 will have a diameter between approximately 1 to 3 feet, and that the pressure of the liquid 26 will be between approximately 100 to 2000 pounds per square inch (psi). For example, a column with a two foot diameter and a liquid pressure of 1200 psi will be capable of resisting approximately 270 tons (i.e. force=pressure×area=1200 psi×⋄/4(2*12)2). In addition, it is anticipated that such a column apparatus 10 or sleeve 22 will have an extended length between approximately 3 to 12 feet. It is understood that such a column could be longer, limited only by buckling. Such a configuration is well suited for use in mining situations.
A method for using the column apparatus 10 described above includes positioning the apparatus 10 or the sleeve 22 in a desired location between the load 14 and the support surface 18. The sleeve 22 preferably is empty, or void of the liquid 26, to facilitate transporting and positioning the apparatus 10. The load 14 or ceiling and the support surface 18 can be prepared beforehand. For example, the support surface 18 and the ceiling may be flattened and/or leveled. The first plate 46 of the base 38 can be positioned to abut, or to be disposed on, the support surface 18. In addition, wedges or shims can be placed between the cap or base and the respective ceiling or floor.
The incompressible liquid 26 can be introduced into the sleeve 22 to lengthen or expand the sleeve 22 to extend between the load 14 and the support surface 18. The sleeve 22 can be filled with the liquid 26. The liquid 26 can be introduced through the valve 96. The valve may be opened to allow the liquid to pass therethrough. The liquid 26 can be introduced from a liquid source, such as a pressurized liquid source. Thus, the liquid 26 in the sleeve 22 also can be pressurized. In addition, the second plate 50 of the cap 42 is positioned to abut the load 14 or ceiling. The valve 96 can then be closed to prevent escape of the liquid.
As discussed above, the ends of the sleeve 22 can be secured to the first and second plates, or the base and the cap 38 and 42, so that the sleeve is sealed. The distance between the load 14 and the support surface 18 can be measured, and the length of the sleeve 22 adjusted to fit therebetween prior to filling the sleeve 22. One end of the sleeve 22 can be pulled through the ring 76 until the sleeve 22 has the desired length. The ring 76 can then be inserted into the base 38.
In the first, collapsed configuration, as shown in
A plurality of such columns can be positioned adjacent one another in an array to form a wall.
Referring to
The column apparatus 10b includes a flexible sleeve 122 and bladder 134 that retain the incompressible liquid 26. The sleeve 122 can be a sleeve assembly, and can include two telescoping sleeves 122a and 122b, or two sleeves that are telescopically engaged. The sleeves 122a and 122b include an overlapping portion so that the bladder 134 is surrounded by the sleeve. Thus, the sleeve 122 can adjust to different heights, or different distances between the support surface 18 or floor of the mine and the load 14 or overhead ceiling of the mine. The bladder 134 is disposed in the sleeve 122. In one aspect, the incompressible liquid 26 can be pressurized and can fill the bladder 134, and the sleeve 122. While either the liquid or the flexible sleeve and bladder alone are incapable of providing support due to their respective liquid or flexible nature, the sleeve 122 and bladder 134 with the liquid 26 contained therein together form a rigid column capable of resisting an applied load. The sleeve 122 can provide strength to resist pressure in the bladder, while the bladder 134 contains the fluid. The bladder 134 can be formed of a flexible, liquid impervious material, such as plastic or rubber.
The flexible sleeve 122 can be formed of a flexible and high-strength material configured to withstand high-tension loads. The material can include a woven fabric material with threads of high tension strength. The sleeve 122 can be formed by wrapping a sheet of the material into a sleeve or cylindrical shape. The sheet can be attached to itself, or edges thereof can be attached, to retain the shape. For example, the sheet or the edges can be attached by an adhesive. In one aspect, the sleeve 122 can include a plurality of layers of the material. For example, the sleeve 122 can be formed by wrapping a single continuous sheet of the material around itself one or more times to form the multiple layers. The multiple layers of material bear against one another and provide a frictional force that resists unwrapping of the sheet. In addition, the sheet or edge thereof can be attached to itself to resist unwrapping. In one aspect, the sleeve 122 has a circular cylindrical shape in the second, load-bearing configuration to evenly distribute pressure in the sleeve 122, and to provide hoop-stress circumferentially around the sleeve 122. In addition, the sleeve 22 can be formed as a continuous weave so that there is no seem.
The flexible sleeve 122 and bladder 134 advantageously have at least two configurations, including a first collapsed, unused, and/or transportable configuration, and a second expanded, in-use, and/or load-bearing configuration. In the first configuration, the sleeve 22 or column apparatus 10b has a first, shorter length. In addition, the sleeve 122 can be collapsed or folded upon itself, and thus has a smaller volume which is substantially unfilled or void of the liquid 26. It will be appreciated that in the first configuration, the column apparatus 10b is smaller and weighs less, thus facilitating transport of the column apparatus 10b, especially into a mine. In the second configuration, the sleeve 122 or column apparatus 10b has a second, longer length that is sized to extend to the load 14 and to the support surface 18. In the second configuration, the first, lower or base end of the apparatus 10b abuts the support surface 18, while the second, upper or cap end abuts the load 14 or ceiling. In addition, the sleeve 122 and bladder 134 are expanded and filled with the liquid 26 so that the flexible sleeve 122, bladder 134 and the fluid 26 form a rigid column to resist the load 14.
The column apparatus 10b can include a base 138, and/or a cap 142. The base 138 is coupled to the first or lower end of the sleeve 122 (or lower sleeve 122b), and is disposed on, or abuts, the support surface 18. Likewise, the cap 142 is coupled to the second or upper end of the sleeve 122 (or upper sleeve 122a), and abuts the load 14 or ceiling. The base 138 and the cap 142 can seal the ends of the sleeve 122 so that together, the sleeve 122, the base 138 and the cap 142 form an enclosure to contain the bladder 134.
The base 138 and the cap 142 can have plates 146 and 150 to bear against the support surface 18 and load 14. In one aspect the plates 146 and 150 are substantially planer or flat. As stated above, the sleeve 122 can be circular. Thus, the base 138 and the cap 142 can be circular. The base 138 and the cap 142, or the plates 146 and 150, provide stability to the sleeve 122. The base 138 and cap 142 can include outer plates 138a and 142a and inner plates 138b and 142b. The ends of the sleeve 122 can be sandwiched between the inner and outer plates 138a and b, and 142a and b. Thus, the base 138 has opposing plates 138a and b, while the cap 142 has opposing plates 142a and b.
The inner and outer plates can include an annular groove 144 formed between the plates. The groove 144 can be formed in both plates, as shown, or in one of the opposing plates. A ring 146 can be disposed in the annular groove 144, in both the base 138 and cap 142. The ends of the sleeve 122 can extend between the opposing plates, around the ring, and back, either terminating between the plates, or extending back out between the plates. Pressure within the enclosure or bladder 134 is utilized to press the inner plates 138a and 142a against the outer plates 142a and 142b, and thus pinch the sleeve 122 between the plates. In addition, the ring 146 is captured in the groove 144, and resists the sleeve from being pulled out from between the plates. Furthermore, the end of the sleeve can be enlarged to further resist slipping between the plates. The plates can be wood and the rings can be steel rings or rope.
The column apparatus 10b can include one or more valves 196 for selectively allowing the fluid 26 into the sleeve 122. In one aspect, the valve can extend through the sleeve 122 and bladder 134. In another aspect, the valve 196 can be operatively coupled to the base 138 or cap 142. The valve 196 can be an inlet valve, or both an inlet and an outlet valve, and can be of any appropriate type, including for example, a check valve, ball valve, gate valve, etc. In addition, the column apparatus 10b can include an emergency pressure release valve configured to automatically release the fluid 26 upon reaching a predetermined pressure.
The base 138 and cap 142 can have a diameter that is less than a diameter of the sleeve 122. Thus, the sleeve 122 resists rubbing on the plates 138a and 142b. In addition, the base and cap 138 and 142 can extend into the bottom and top of the sleeve 122, as shown in
The column apparatus 10b advantageously utilizes the flexible and high-strength sleeve 122, bladder 13 and incompressible fluid 26 to provide a collapsible, load-bearing structure. The flexibility of the sleeve 122 and bladder 134 and the fluid nature of the liquid 26 allow the column apparatus 10b to be collapsible to a smaller, lighter, flexible configuration for transportation, and expandable to a larger, load-bearing, rigid structure. As described above, while neither the flexible sleeve 122 and bladder 134 or liquid 26 alone provides support or resists the load, together the sleeve 122 and bladder 134 with the liquid 26 contained therein form a rigid, load-bearing structure capable of supporting the load 14, or resisting movement thereof.
A method for using the column apparatus 10b described above includes positioning the apparatus in a desired location between the load 14 and the support surface 18. The sleeve 122 or bladder 134 preferably is empty, or void of the liquid 26, to facilitate transporting and positioning the apparatus lob. The incompressible liquid 26 can be introduced into the bladder 134 to lengthen or expand the sleeve 122 to extend between the load 14 and the support surface 18. As the bladder 134 fills, the sleeves 122a and 122b can slide with respect to one another.
A plurality of such columns can be arranged in an array, and intercoupled together or fluidly coupled together, so that the plurality of columns act together and pressure stabilize one another.
It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiments(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth in the claims.
