Load-bearing pressurized liquid column

Information

  • Patent Grant
  • 6637159
  • Patent Number
    6,637,159
  • Date Filed
    Tuesday, November 27, 2001
    23 years ago
  • Date Issued
    Tuesday, October 28, 2003
    21 years ago
Abstract
A load-bearing, pressurized-fluid column apparatus and method for supporting a load or mine ceiling with respect to a support surface or mine floor includes an elongated, flexible sleeve retains a substantially incompressible liquid. The elongated, flexible sleeve has a collapsed and an expanded configuration. In the collapsed configuration, the sleeve is not filled, and has a first, shorter length. In the expanded configuration, the sleeve is filled with the liquid, and has a second, longer length sized to extend to and between the load and the support surface. A valve allows the liquid to be added and prevents escape of the liquid. A base can seal a lower end of the sleeve, and can be disposed on the support surface. A cap can seal an upper end of the sleeve, and can be capable of abutting the load.
Description




BACKGROUND OF THE INVENTION




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.




SUMMARY OF THE INVENTION




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 retains 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 sleeve is not filled, and has a first, shorter length. In the expanded or rigid configuration, the sleeve 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 a flexible, high strength woven fabric to withstand high-tension loads, and 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.




A method for utilizing the column apparatus for supporting a load with respect to a support surface includes positioning a flexible sleeve in a desired location between the load and the support surface. A substantially incompressible liquid is introduced into the sleeve 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 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.




BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side view of a load-bearing column apparatus in accordance with an embodiment of the present invention shown in an expanded configuration supporting a load;





FIG. 2

is a cross-sectional view of the apparatus of

FIG. 1

;





FIG. 3

is a cross-sectional view of the apparatus of

FIG. 1

, shown in a collapsed configuration;





FIG. 4

is a partial, cross-sectional detailed view of a portion of a sleeve of the apparatus of

FIG. 1

;





FIG. 5

is a cross-sectional view of a cap of the apparatus of

FIG. 1

; and





FIG. 6

is a cross-sectional view of a base of the apparatus of FIG.


1


.











DETAILED DESCRIPTION




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

FIGS. 1-3

, a load-bearing, pressurized-fluid column apparatus, indicated generally at


10


, in accordance with the present invention is shown for supporting a load


14


with respect to a support surface


18


. Mining is an example of one field that may benefit from the use of such an apparatus


10


. Thus, the load


14


can be the force of an overhead ceiling in a mine, while the support surface


18


can be the floor underneath the load


14


in the mine. As described above, it will be appreciated that mining removes material leaving the material, load or ceiling above it without support. The apparatus


10


is shown in the drawings and described herein configured for use in mining. It will of course be understood that such an apparatus can be configured for use in other fields.




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

FIG. 3

, and a second expanded, in-use, and/or load-bearing configuration, as shown in

FIGS. 1 and 2

. Referring to

FIG. 3

, in the first configuration, the sleeve


22


or column apparatus


10


has a first, shorter length. In addition, the sleeve


22


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


10


is smaller and weighs less, thus facilitating transport of the column apparatus


10


, especially into a mine.




Referring to

FIGS. 1 and 2

, in the second configuration, the sleeve


22


or column apparatus


10


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


10


abuts the support surface


18


, while the second, upper or cap end abuts the load


14


or ceiling. In addition, the sleeve


22


is expanded and filled with the liquid


26


so that the flexible sleeve


22


and the fluid


26


form a rigid column to resist the load


14


. The sleeve


22


and the column apparatus


10


have a longitudinal axis along the length thereof, and along which the sleeve


22


expands and/or collapses.




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

FIG. 4

, the sleeve


22


can include an outer layer


30


formed by the high-strength material, and an inner layer or bladder


34


. The outer layer


30


can provide strength to resist pressure in the sleeve, while the inner layer or bladder


34


contains the fluid. The bladder


34


can be formed of a flexible, liquid impervious material, such as plastic or rubber.




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

FIGS. 1 and 2

, the column apparatus


10


can include a base


38


, and/or a cap


42


. The base


38


is coupled to the first or lower end of the sleeve


22


, and is disposed on, or abuts, the support surface


18


. Likewise, the cap


42


is coupled to the second or upper end of the sleeve


22


, and abuts the load


14


or ceiling. The base


38


and the cap


42


can seal the ends of the sleeve


22


so that together, the sleeve


22


, the base


38


and the cap


42


form an enclosure to contain the liquid


26


. The enclosure, sleeve


22


, and/or column apparatus


10


extends between the load


14


and the base support


18


, and thus can be elongated with a longitudinal axis parallel to a direction of a force of the load


14


, or perpendicular to the ceiling and support surface


18


.




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

FIG. 5

, the second or upper end of the sleeve


22


can be fixedly coupled to the cap


42


. The second or upper end of the sleeve


22


can be wrapped around a ring


58


and inserted into the receptacle or outer annular wall


54


. Pressure within the enclosure or sleeve


22


is utilized to press the sleeve


22


against the ring


58


, and thus press the folded portion of the sleeve against the annular wall


54


. Thus, the pressure causes the folded portion of the sleeve to be pinched between the ring


58


and the annular wall


54


to secure the sleeve


22


to the cap


42


.




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

FIG. 6

, the first or lower end of the sleeve


22


advantageously can be adjustably coupled to the base


38


. Therefore, the length of the sleeve


22


, and thus the column apparatus


10


, advantageously can be adjusted to extend between the load


14


and the support surface


18


. The first or lower end of the sleeve


22


can be removably disposed in the receptacle of the base


38


, and selectively coupled thereto. The sleeve


22


can be wrapped around a ring


76


that also is removably disposed in the annular wall


54


of the base


38


. Like the cap


42


(FIG.


5


), the base


38


can include an inner annular wall


60


forming a gap


80


between itself and the outer annular wall


54


. The gap


80


is sized so that the ring


76


with the sleeve


22


wrapped therearound can be selectively slid into and out of the gap


80


. To adjust the length of the sleeve


22


and/or column apparatus


10


, the sleeve


22


is wrapped around the ring


76


and the ring


76


positioned along a length of the sleeve


22


to achieve the desired length.




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

FIG. 5

, so that the sleeve


22


and the column apparatus


10


has a fixed length. Similarly, it will be understood that one or both ends of the sleeve


22


can be adjustably coupled to the cap


14


and the base


18


, as described above and illustrated in

FIG. 6

, so that the sleeve


22


and column apparatus


10


can have an adjustable length. In addition, it is understood that the ends of the sleeve


22


can be coupled to the cap


14


and base


18


in any appropriate manner.




Referring again to

FIG. 5

, additional seals can be provided to resist leaking between the sleeve


22


and the cap


42


or base


38


(FIG.


6


). For example, a seal


84


can be positioned in the bottom of the gap


64


or


80


(FIG.


6


). Similarly, a seal


88


can be positioned in the top of the gap


64


or


80


(FIG.


6


). The seals can be of any appropriate type, such as, for example, o-rings, etc. In addition, the cap


42


and/or base


38


(

FIG. 6

) can include reinforcement rings


92


formed around the outer annular wall


54


to reinforce the wall.




Referring to

FIGS. 1

,


2


and


6


, the column apparatus can include a valve


96


for selectively allowing the fluid


26


into the sleeve


22


. In one aspect, the valve


96


is operatively coupled to the base


18


. The valve


96


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


10


can include an emergency pressure release valve


100


configured to automatically release the fluid


26


upon reaching a predetermined pressure. Thus, the release valve


100


resists catastrophic failure of the apparatus.




Referring again to

FIG. 1

, the column apparatus


10


can include one or more rods or cables


104


extending between the base


38


and the cap


42


to limit the longitudinal extension or length of the apparatus


10


. The rod or cable


104


can be coupled to the plates


46


and


50


of the base


38


and cap


42


. A plurality of such rods or cables


104


spaced around the sleeve


22


can help maintain the plates


46


and


50


in a parallel relationship, and improve the stability of the apparatus. The rods or cables are examples of a means for limiting longitudinal extension of the sleeve. It is of course understood that the rods or cables can be adjustable in length, or adjustably coupled to the base and cap.




Referring again to

FIGS. 1-3

, the column apparatus


10


advantageously utilizes the flexible and high-strength sleeve


22


and incompressible fluid


26


to provide a collapsible, load-bearing structure. The flexibility of the sleeve


22


and the fluid nature of the liquid


26


allow the column apparatus


10


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


22


or liquid


26


alone provides support or resists the load, together the sleeve


22


with the liquid


26


contained therein form a rigid, load-bearing structure capable of supporting the load


14


, or resisting movement thereof.




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


determined, 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×π/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


12


described above includes positioning the apparatus


12


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

FIG. 3

, the sleeve


22


may be folded and disposed in the cap


42


and the base


38


so that the cap and the base form a container containing the sleeve. Such a configuration can assist in transporting the apparatus.




A plurality of such columns can be positioned adjacent one another in an array to form a wall.




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.



Claims
  • 1. A load-bearing column apparatus configured to support a load with respect to a support surface, the apparatus comprising:a) a base configured to abut the support surface; b) a cap configured to abut the load; c) an elongated, flexible sleeve having opposite ends, one end being coupled to the base and the other end being coupled to the cap to form an enclosure configured to extend to and between the load and the support; d) an incompressible liquid, selectively disposable in the sleeve; e) the elongated, flexible sleeve having at least two configurations, including: 1) a collapsed configuration in which the sleeve is not filled and has a first, shorter length; and 2) an expanded configuration in which the sleeve is filled with the liquid and has a second, longer length sized to extend to and between the load and the support surface; and f) a valve to allow the liquid to be added to the sleeve and prevent escape of the liquid from the sleeve; g) at least one of the ends of the sleeves being adjustable 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.
  • 2. An apparatus in accordance with claim 1, further comprising:a) a flexible, high strength woven fabric configured to withstand high tension loads; and b) a flexible, liquid impervious layer configured to contain liquid.
  • 3. An apparatus in accordance with claim 1, wherein the sleeve has a circular, cylindrical shape in the expanded configuration configured to withstand tension loads.
  • 4. An apparatus in accordance with claim 1, further comprising:a) a ring, securable to either the cap or the base; and b) one end of the sleeve being wrapped around the ring and selectively slidable around the ring to adjust the length of the sleeve and the distance between the cap and the base.
  • 5. An apparatus in accordance with claim 1, further comprising:a) means for limiting longitudinal extension of the sleeve.
  • 6. A load-bearing column apparatus configured to support a load above a support surface, the apparatus comprising:a) a base, configured to be disposed on the support surface; b) a cap, disposed over the base and configured to be capable of abutting the load; c) a flexible, elongated sleeve having opposite ends, one end being coupled to the base and the other end being coupled to the cap to form an enclosure configured to extend to and between the load and the support surface; d) an incompressible liquid, selectively disposable in the enclosure formed by the sleeve, the base and the cap; and e) a valve, operatively coupled to the enclosure, configured to allow the incompressible fluid into the enclosure; and f) the flexible sleeve having at least two configurations, including: 1) a collapsed configuration in which the enclosure is not filled with the incompressible fluid and has a first, shorter length; and 2) a rigid configuration in which the enclosure is filled with the incompressible liquid and has a second, longer length sized so that the cap abuts the load and the base abuts the support surface, and in which the incompressible liquid is pressurized so that the incompressible liquid is configured to be capable of transferring a compressive force of the load to tension load in the sleeve; g) a ring, securable to either the cap or the base; and h) one end of the sleeve being wrapped around the ring and selectively slidable around the ring to adjust the length of the sleeve and the distance between the cap and the base.
  • 7. An apparatus in accordance with claim 6, wherein the sleeve further includes:a) a flexible, high strength woven fabric configured to withstand high tension loads; and b) a flexible, liquid impervious layer configured to contain liquid.
  • 8. An apparatus in accordance with claim 6, wherein the sleeve has a circular, cylindrical shape in the expanded configuration configured to withstand tension loads.
  • 9. An apparatus in accordance with claim 6, wherein 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.
  • 10. An apparatus in accordance with claim 6, further comprising:a) a rod or a cable having opposite ends secured to the respective base and cap to limit longitudinal extension of the sleeve.
  • 11. A method for supporting a ceiling of a mine with respect to a floor of the mine, comprising the steps of:a) positioning a flexible sleeve in a desired location between the ceiling and the floor of the mine; b) positioning a first plate to abut the floor; c) securing a first end of the sleeve to the first plate so that the first plate seals the first end of the sleeve; d) securing a second end of the sleeve to a second plate so that the second plate seals the second end of the sleeve; e) positioning the second plate to abut the ceiling; f) introducing a substantially incompressible liquid into the sleeve; and g) preventing escape of the liquid from the sleeve so that the volume of the sleeve between the ceiling and the floor of the mine is maintained at a substantially constant value so as to resist movement of the ceiling towards the floor of the mine.
  • 12. A method in accordance with claim 11, further comprising the step of:pressurizing the liquid in the sleeve.
  • 13. A method in accordance with claim 11, wherein the step of introducing a liquid into the sleeve further includes opening a valve; and wherein the step of preventing escape of the liquid includes closing the valve.
  • 14. A method in accordance with claim 11, wherein the step of positioning a sleeve includes positioning a sleeve formed of a flexible, high tensile strength, woven material, and a liquid resistant material.
  • 15. A method in accordance with claim 11, wherein the step of positioning a sleeve includes positioning a sleeve having a circular tubular shape and a longitudinal axis oriented parallel to a load exerted by the ceiling of the mine.
  • 16. A method in accordance with claim 11, further comprising the step of:a) adjusting the length of the sleeve to extend to and between the load and the support surface.
  • 17. A method in accordance with claim 16, wherein the step of adjusting the length of the sleeve further includes:a) wrapping an end of the sleeve around a ring.
Parent Case Info

This application claims the benefit of U.S. Provisional Application Ser. No. 60/253,664, filed Nov. 28, 2000.

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Provisional Applications (1)
Number Date Country
60/253664 Nov 2000 US