Abstract:
A fluid-powered cylinder for displacing an object with respect to a support surface is disclosed. The fluid-power cylinder includes a fabric enclosure having ends fastened to two end caps and forming an expandable and contractible chamber therein. The chamber has a port for selectively disposing an incompressible fluid in the chamber. The chamber is adapted to displace the object to a first position with respect to the support surface and to displace the object to a second position with respect to the support surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims benefit of U.S. provisional application Ser. No. 61/100,070 filed on Sep. 25, 2008, and entitled “Fabric Fluid-Powered Cylinder,” which is hereby incorporated herein by reference in its entirety for all purposes. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    The present invention relates generally to pneumatic and hydraulic cylinders and, more particularly, to a fabric fluid-powered cylinder. 
         [0005]    2. Description of Related Art 
         [0006]    Pneumatic and hydraulic cylinders generally include a rigid housing having dimensions and weight that limit the range of locations where such cylinders may be used and stored. Also, depending on the loads for which these cylinders are designed, and thus, their overall size, often these cylinders are not easily portable or designed to be portable from one operation site to the next. For those cylinders that are portable, such as a jack for a car, their capacity for lifting and range of extension is limited. 
         [0007]    Thus, there exists a need for a flexible fluid-powered cylinder that may be transported to an operation site in a collapsed state, expanded at the operation site to displace an object, subsequently refracted to lower the object when desired, and collapsed when empty to minimize storage requirements. It would be particularly advantageous if the fluid-powered cylinder had minimal weight to reduce associated transportation costs and facilitate its positioning for use, and was nonconductive to protect the object from electrical hazards. 
       SUMMARY OF THE PREFERRED EMBODIMENTS 
       [0008]    An apparatus for displacing an object is disclosed. In some embodiments, the apparatus includes a fabric enclosure having ends fastened to two end caps and forming an expandable and contractible chamber therein. The chamber has a port for selectively disposing an incompressible fluid in the chamber. The chamber is adapted to displace the object to a first position with respect to the support surface and to displace the object to a second position with respect to the support surface. 
         [0009]    In some embodiments, the apparatus includes a first end cap assembly and a second end cap assembly, a sleeve disposed therebetween, and a closeable fluid port extending through one of the first and the second end cap assemblies. The sleeve comprises fabric and is coated over an inner surface, thereby forming a bladder that is impermeable to fluid. The fluid port is configured to allow fluid communication with the bladder. 
         [0010]    Some methods for displacing an object with respect to a support surface include positioning an expandable/contractible enclosure between the object and support surface, injecting a fluid through a fluid port in the expandable/contractible enclosure to expand the expandable/contractible enclosure, guiding the expansion of the expandable/contractible enclosure in a longitudinal direction, extending the sleeve as fluid accumulates in the expandable/contractible enclosure, and displacing the object from a first position to a second position as the expandable/contractible enclosure expands. 
         [0011]    Thus, the enclosure comprises a combination of features and advantages that enable it to provide a high-strength, yet lightweight fluid-powered lifting or displacing apparatus. These and various other characteristics and advantages of the preferred embodiments will be readily apparent to those skilled in the art upon reading the following detailed description and by referring to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    For a more detailed understanding of the preferred embodiments, reference is made to the accompanying Figures, wherein: 
           [0013]      FIGS. 1A ,  1 B and  1 C are side, end and cross-sectional views, respectively, of a fabric fluid-powered cylinder in accordance with the principles disclosed herein; 
           [0014]      FIGS. 2A and 2B  are a cross-sectional and enlarged cross-sectional views, respectively, of the fluid-powered cylinder of  FIG. 1A ; 
           [0015]      FIG. 3A-3C  are side, end and cross-sectional views, respectively, of the collet collar of the fluid-powered cylinder of  FIG. 1A ; 
           [0016]      FIGS. 4A-4C  are side, end and cross-sectional views, respectively, of the collet plug of the fluid-powered cylinder of  FIG. 1A ; 
           [0017]      FIGS. 5A and 5B  are end and side views, respectively, of the inner clamping ring of the fluid-powered cylinder of  FIG. 1A ; 
           [0018]      FIGS. 6A and 6B  are end and side views, respectively, of the outer clamping ring of the fluid-powered cylinder of  FIG. 1A ; 
           [0019]      FIGS. 7A-7C  are interior end, exterior end and side views, respectively, of the cap of the fluid-powered cylinder of  FIG. 1A ; 
           [0020]      FIGS. 8A and 8B  are exploded, side and exploded cross-sectional side views, respectively, of the fluid-powered cylinder of  FIG. 1A ; 
           [0021]      FIGS. 9A and 9B  illustrate coupling of one end cap assembly to the pressure sleeve of the fluid-powered cylinder of  FIG. 1A  via bonding; 
           [0022]      FIG. 10  depicts the fluid-powered cylinder of  FIG. 1A  oriented horizontally to displace an object; 
           [0023]      FIG. 11  depicts the fluid-powered cylinder of  FIG. 1A  oriented vertically to displace an object; 
           [0024]      FIG. 12  depicts the fluid-powered cylinder of  FIG. 1A  with an internal winch system configured to constrain the cylinder along the longitudinal axis and to limit the extended length of the cylinder; and 
           [0025]      FIG. 13  depicts the fluid-powered cylinder of  FIG. 1A  in operation. 
       
    
    
     NOTATION AND NOMENCLATURE 
       [0026]    Certain terms are used throughout the following description and claims to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function. Moreover, the drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. 
         [0027]    In the following discussion and in the claims, the term “comprises” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    Referring to  FIGS. 1A and 1B , there are shown side and end views, respectively, of an embodiment of a fabric fluid-powered cylinder (hereinafter “cylinder”)  100  for displacing an object. Cylinder  100  includes two end cap assemblies  105 ,  110  with a pressure sleeve  115  extending therebetween. In some embodiments, pressure sleeve  115  has a generally cylindrical and preferably seamless shape. The dimensions of pressure sleeve  115 , such as its diameter and length, are selected depending on the environment in which cylinder  100  is to be used and/or the weight and size of objects to be displaced by cylinder  100 . For particular applications where minimal space exists for placement of cylinder  100 , for example, its diameter may be relatively small. On the other hand, for applications where large, heavy objects are to be displaced, the diameter of cylinder  100  may be significantly larger. 
         [0029]    Pressure sleeve  115  is preferably made of a braided fabric  120 . Alternatively, fabric  120  of pressure sleeve  115  may be woven, knitted or constructed by other fabric-forming methods known in the industry. Fabric  120  is high-strength, while at the same time, lightweight. Thus, pressure sleeve  115  has the structural capacity to contain high-pressure fluids, both liquids and gases. The thickness and other properties of fabric  120  may be tailored as a function of the weight of the fluid pressure to be contained within cylinder  100 . Pressure sleeve  115  has minimal weight, which facilitates handling and reduces transportation costs for moving cylinder  100  between storage and usage locations. 
         [0030]    Fabric  120  of pressure sleeve  115  is tear-resistant. As such, cylinder  100  may be stowed in virtually any orientation, including on its side, without risk of damage. Fabric  120  is flexible or pliable and allows cylinder  100  to collapse when empty, thereby occupying only a fraction of the storage space required when cylinder  100  is extended to displace an object. 
         [0031]    As best viewed in  FIG. 1C , pressure sleeve  115  includes an outer surface  125  and an inner surface  130 , both of which are coated Inner surface  130  is coated with a material  135  to form a bladder  140 . Alternatively, bladder  140  may be formed by a separate sleeve inserted into pressure sleeve  115  and secured therein. Bladder  140  enables pressure sleeve  115  to be impermeable to materials disposed therein and enables pressure sleeve  115  to contain fluid, either gas or liquid, including pressurized gases or inert gases. Further, material  135  of bladder  140  may be selected such that it adheres well to the fibers of fabric  120  and is compatible with the expected range of fluids to be introduced to cylinder  100 . Outer surface  125  of pressure sleeve  115  is coated with a material  145  to form a coating  150 . Coating  150  prevents environmental damage to pressure sleeve  115  from ultraviolet light radiation, ozone in the atmosphere, weather in general, and abrasion during handling of cylinder  100 . 
         [0032]    In some embodiments, material  135  of bladder  140  over inner surface  130  may be different than material  145  of coating  150  over outer surface  125 . However, in preferred embodiments, materials  135 ,  145  both include polyurethane. A suitable polyurethane has an adhesive property which enables it to adhere to fabric  120  of pressure sleeve  115 . Further, polyurethane can stretch and deform without cracking. Thus, pressure sleeve  115  may be extended and collapsed repeatedly without damage to either bladder  140 , resulting in loss of or diminished pressure-containment ability of cylinder  100 , or coating  150 , leaving pressure sleeve  115  susceptible to damage from environmental sources. Other materials having functionally equivalent properties to polyurethane may be alternatively used. 
         [0033]    Fabric  120  of pressure sleeve  115  preferably includes braided Vectran® made by Kuraray or high performance polyaramids, such as Kevlar®, with axially-oriented fibers of grade E fiberglass, or e-glass. Vectran® is a manufactured fiber spun from a liquid crystal polymer. Vectran® is noted for its high strength, thermal stability at high temperatures, abrasion resistance, low density, low creep, low electrical conductivity and chemical stability. Vectran® has a tensile strength as high as 3.2 GPa, which is generally five times the strength of typical steel and ten times the strength of aluminum. The abrasion resistance of Vectran® is ten times more than that of competing aramid fibers, as measured by Cordage Institute Test Method CI-1503. Vectran® has a density approximately equal to 1.4 gm/cc. By comparison, the approximate densities of aluminum and stainless steel are 2.8 gm/cc and 7.4 gm/cc, respectively. Further, Vectran® is resistant to moisture and ultraviolet radiation. When combined, e.g., interwoven, with braided or woven Vectran®, e-glass stablizes the Vectran® and prevents the Vectran® from unraveling. Also, like Vectran®, e-glass has high strength and is lightweight. While fabric  120  of pressure sleeve  115  preferably includes Vectran® and e-glass, other materials, either individually or in combination, having functionally equivalent properties may be used instead. 
         [0034]    Turning now to  FIGS. 2A and 2B , end cap assemblies  105 ,  110  are substantially identical in this exemplary embodiment. For the sake of brevity, end cap assembly  110  is now described. However, this description also applies to end cap assembly  105 . End cap assembly  110  includes a collet collar  160 , a collet plug  165  inserted therein, a cap  170 , one or more compressible biasing members  175 , for example, springs, disposed between plug  165  and cap  170 , an inner clamping ring  185 , and an clamping outer ring  180 . 
         [0035]    Referring next to  FIGS. 3A-3C , collet collar  160  is generally tubular in shape, having a central bore  300  extending between a first end  305  and a second, flanged end  310 . The inner diameter of collet collar  160  at first end  305  is less than the inner diameter of collet collar  160  at flanged end  310 . Thus, collet collar  160  has a tapered, conical shaped inner surface  315 . Collet collar  160  further includes a fluid port  330 , a plurality of threaded bores  320  spaced circumferentially about an outer surface  325  of flanged end  310 , and a shoulder  335  disposed in inner surface  315  formed by a counterbore portion  360  proximate flanged end  310 . As will be described below, threaded bores  320  enable coupling of cap  170  to collet collar  160 . Fluid port  330  extends through flanged end  310  of collet collar  160  and enables injection of fluid into and/or flow of fluid from cylinder  100 . 
         [0036]    Turning to  FIGS. 4A-4C , collet plug  165  is also conical in shape, having a body  400  disposed between an open end  405  and a closed end  410 . The outer diameter of plug  165  at open end  405  is less than the outer diameter of plug  165  at closed end  410 . Thus, body  400  has a tapered outer surface  415 . Closed end  410  of plug  165  includes one or more extensions  420  projecting in a substantially normal direction therefrom and one or more flowbores  425  through end  410  between extensions  420 . Each extension  420  is configured to receive a biasing member  175  ( FIG. 1A ), such as a spring, thereon, and in this exemplary embodiment, are generally cylindrical in shape. Flowbores  425  permit fluid flow therethrough. 
         [0037]    Referring now to  FIGS. 5A and 5B , inner clamping ring  185  is circular in shape, having an inner diameter  500 , an outer diameter  505 , and a plurality of threaded bores  515  azimuthally spaced around its periphery. Outer diameter  505  is selected to enable insertion of inner clamping ring  185  into central bore  300  of collet collar  160 , as shown in  FIGS. 2A and 2B  Inner diameter  500  is selected to enable cap  170  to be inserted at least partially therein, also as shown in  FIGS. 2A and 2B . Threaded bores  515  enable the coupling of inner and outer clamping rings  185 ,  180  with pressure sleeve  115  secured therebetween, as shown in  FIG. 2B  and described in more detail below. 
         [0038]    Turning to  FIGS. 6A and 6B , outer clamping ring  180  is also circular in shape, having an inner diameter  600 , an outer diameter  605 , and a plurality of throughbores  615  azimuthally spaced around its inner diameter  600 . Outer diameter  605  is selected to enable outer clamping ring  180  to be inserted into counterbore  360  of flanged end  310  of collet collar  160  and seated on shoulder  335  of collet collar  160 , as shown in  FIGS. 2A and 2B  Inner diameter  600  is selected to enable cap  170  to be inserted at least partially therein, also as shown in  FIGS. 2A and 2B . Throughbores  615  of outer clamping ring  180  align with threaded bores  515  of inner clamping ring  185  when clamping rings  180 ,  185  are assembled within collet collar  160 . When so aligned, a plurality of threaded bolts  195  ( FIG. 2A ) are inserted through bores  615  of outer clamping ring  180 , an end of pressure sleeve  115 , sandwiched between outer and inner clamping rings  180 ,  185 , and threaded into bores  515 , as shown in  FIG. 2B . 
         [0039]    Referring to  FIGS. 7A-7C , cap  170  includes a circular plate  700  having an inner surface  705 , an outer surface  710 , a plurality of stiffening members or ribs  715  coupled, such as by welding, to inner surface  705  and extending substantially normal therefrom, and a plurality of threaded bores  720  azimuthally spaced around its circumference. Ribs  715  are configured to promote the structural integrity of plate  700  and prevent plate  700  from bending or flexing when assembled with the remaining components of end cap assembly  110 . Threaded bores  720  of cap  170  align with threaded bores  320  ( FIG. 3A ) of collet collar  160  when cap  170  is assembled with collet collar  160 , as shown in  FIG. 2B . When so aligned, a plurality of threaded bolts  200  are inserted through bores  720  and threaded into bores  320  to couple cap  170  to collet collar  160 . 
         [0040]    The assembly of cylinder  100  is best described with initial reference to  FIGS. 8A and 8B , which are exploded, side views of cylinder  100 , the latter in cross-section. Pressure sleeve  115  is first coated prior to assembly of cylinder  100  in order to protect outer surface  125  and form bladder  140  along inner surface  130 . To assemble cylinder  100 , end cap assembly  110  is coupled to pressure sleeve  115 . An end  800  of pressure sleeve  115  is inserted through end  305  of collet collar  160  such that end  800  extends from throughbore  300  beyond flanged end  310  Inner clamping ring  185  is then inserted within end  800  of pressure sleeve  115 , as shown in  FIGS. 8B and 2B . Turning now to  FIG. 2B , end  800  is folded over inner clamping ring  185 . Outer clamping ring  180  is then positioned over folded end  800  of pressure sleeve  115  against inner clamping ring  185  such that bores  615  ( FIG. 6A ) of outer clamping ring  180  align with threaded bores  515  ( FIG. 5A ) of inner clamping ring  185 . Apertures  805  ( FIG. 2B ) are made in end  800  of pressure sleeve  115  to receive bolts  195  ( FIG. 2B ). When outer clamping ring  180  is aligned with inner clamping ring  185  in this manner, bolts  195  are then inserted through bores  615  of outer clamping ring  180  and end  800  of pressure sleeve  115  and threaded into bores  515  of inner clamping ring  185 . Once bolts  195  are installed in this manner, end  800  of pressure sleeve  115  is securely sandwiched between clamping rings  180 ,  185  and may not come loose from this coupling. 
         [0041]    Outer clamping ring  180 , with pressure sleeve  115  and inner clamping ring  185  coupled thereto, is then seated on shoulder  335  of collet collar  160 . Collet plug  165  is then inserted through inner and outer clamping rings  185 ,  180  into pressure sleeve  115  and collet collar  160 , as shown in  FIG. 2A . Tapered inner surface  315  of collet collar  160  limits the depth to which plug  165  is insertable within collet collar  160  and enables a snug fit of plug  165  with collar  160  with pressure sleeve  115  sandwiched therebetween. 
         [0042]    Next, cap  170  is assembled to collet collar  160  over collet plug  165 . Springs  175  are installed over extensions  420  of plug  165 , and cap  170  is positioned against flanged end  310  of collet collar  160 , such that ribs  715  of cap  170  are disposed between extensions  420 , bores  720  of cap  170  are aligned with threaded bores  320  on flanged end  310 , and springs  175  are compressed between plug  165  and cap  170 . Cap screws  200  are then inserted through bore  720  and threaded into bores  320  to couple cap  170  to collet collar  160 . Lastly, end cap assembly  105  is coupled to pressure sleeve  115  following substantially the same steps to complete assembly of cylinder  100 . 
         [0043]    Once installed, springs  175  expand against plug  165 , and thus provide a continual load against plug  165  in the absence of an internal pressure load from fluid within cylinder  100 . During operation of cylinder  100 , fluid is injected through port  330  of collet collar  160  into the inner chamber of cylinder  100 . As fluid pressure within cylinder  100  increases, pressure sleeve  115  is gripped along two interfaces, one between tapered collet collar  160  and collet plug  165  and the other between clamping rings  180 ,  185 . Thus, end cap assembly  110  is prevented from disengaging pressure sleeve  115  as the pressure rises. Due to the tapered nature of collet collar  160  and collet plug  165 , end cap assembly  110  grips pressure sleeve  115  increasingly tighter as fluid pressure within cylinder  100  increases. At the same time, end  800  of pressure sleeve  115  is gripped between clamping rings  180 ,  185 . By securing pressure sleeve  115  to end cap assembly  110  at two interfaces, the load on pressure sleeve  115  is distributed and assembly  110  is prevented from crushing fabric  120  of pressure sleeve  115  and causing failure of pressure sleeve  115 . 
         [0044]    In alternative embodiments of cylinder  100 , pressure sleeve  115  is coupled to collet collar  160  and collet plug  165  via bonding. In such embodiments, clamping rings  180 ,  185  and bolts  195  are not needed. Aside from these differences, cylinder  100 , and its assembly, is essentially the same as described above. To couple end cap assembly  110  to pressure sleeve  115  via bonding, as illustrated by  FIGS. 9A and 9B , a layer of bonding material  900  is applied to inner surface  315  of collet collar  160 , including shoulder  335  and outer surface  325 . End  800  of pressure sleeve  115  is inserted through end  305  ( FIG. 3C ) of collet collar  160  and central bore  300  to flanged end  310 . Pressure sleeve  115  is then pressed against inner surface  315  to allow material  900  to adhere to pressure sleeve  115  and collet collar  160 . When material  900  dries, a bond  905  is formed between collet collar  160  and pressure sleeve  115  at this interface. 
         [0045]    Next, collet plug  165  is installed within end  800  of pressure sleeve  115  and collet collar  160 . A layer of bonding material  910  is applied to outer surface  415  of collet plug  165 . End  405  of plug  165  is then inserted into flanged end  310  of collet collar  160  and end  800  of pressure sleeve  115 , such that outer surface  415  substantially aligns with inner surface  315  of collet collar  160  and in contact with end  800  of pressure sleeve  115  disposed therebetween. When material  910  dries, a bond  915  is formed between plug  165  and pressure sleeve  115  at this interface. 
         [0046]    The length of collet collar  160  from end  305  to end  310  and the length of plug  165  from end  405  to end  410  are selected such that the shear loads at bonds  905 ,  915  do not cause these bonds  905 ,  915  to fail during operation of cylinder  100 . In other words, these lengths are chosen such that the shear load resulting from pressurized fluid contained within cylinder  100  is distributed over sufficient area to prevent failure of bonds  905 ,  915 . In some embodiments, these lengths are approximately four inches. 
         [0047]    Cylinder  100  is extendable longitudinally in virtually any direction to displace an object. For instance, as shown in  FIG. 10 , cylinder  100  may be positioned on its side and supported by a fixed surface  950  with end cap assembly  110  positioned against a fixed surface  955 . When a fluid is injected into cylinder  100  through fluid port  330 , cylinder  100  inflates and extends laterally or horizontally, defined relative to surface  950 , thereby displacing an object  960  positioned adjacent end cap assembly  105  over surface  950 . 
         [0048]    Alternatively, as shown in  FIG. 11 , cylinder  100  may be positioned on a fixed surface  950  such that when inflated, cylinder  100  extends vertically upward to displace an object  960 . In such applications, cylinder  100  may further include a guide  965  disposed within cylinder  100 . Guide  965  has a height slightly less than the relaxed or deflated height of cylinder  100  and is made of a rigid material, such as but not limited to plastic. In some embodiments, guide  965  includes a cylindrical body  970  with a hemispherical end cap  975  coupled thereto. Body  970  of guide  965  is coupled to end cap assembly  110 , for example, by one or more bolts or other equivalent fastening means, to limit lateral movement of guide  965  relative to end cap assembly  110 . 
         [0049]    Guide  965  enables extension of cylinder  100  substantially in the vertical direction and prevents cylinder  100  from collapsing to one side or another due to the flexibility of fabric  120  of pressure sleeve  115 , the weight of object  960 , and the initial low pressure within pressure sleeve  115  at the onset of inflation. Further, the curved nature of hemispherical end cap  975  of guide  965  enables retraction of cylinder  100  in the substantially vertical direction as well. As fluid is vented from cylinder  100 , the fabric  120  of pressure sleeve  115  slides downward over end cap  975  and cylinder  100  retracts about or around guide  965 . 
         [0050]    In the exemplary embodiments illustrated by  FIGS. 10 and 11 , the extended length of cylinder  100  is limited solely by the overall length of cylinder  100 . However, in some instances, it may be desirable to inflate or extend cylinder  100  to only a fraction of its overall length. For example, it may be desirable to displace object  960  to a height of 20 feet, even though cylinder  100  is capable of extending to a length of 100 feet. In such applications, illustrated by  FIG. 12 , cylinder  100  further includes a length adjustment means that extends between the ends of cylinder  100  to control the longitudinal expansion of cylinder  100 . One such means is a winch system  980  disposed within pressure sleeve  115  and coupled to end cap assembly  110 , for example, by one or more bolts or other equivalent fastening means. Winch system  980  includes a winch  985  and a cable or line  990  extending therefrom and coupled to end cap assembly  105 . 
         [0051]    Winch  985  is configured to limit the length of cable  990  which may be dispensed therefrom, and thus the extended length of cylinder  100  when inflated. For example, winch  985  may be configured to allow only 20 feet of cable  990  to dispense. As a result, when cylinder  100  is inflated, the extended length of cylinder  100  is limited to the length of cable  990  allowed to be dispensed from winch  985 , or 20 feet in the above example. When the length of cable  990  dispensed from winch  985  reaches its preset limit, cylinder  100  is prevented from further extension despite any continued injection of fluid into cylinder  100 . Thus, the extended length of cylinder  100  is limited to 20 feet, for example, although cylinder  100  may be capable of extending further, such as to 100 feet. In these embodiments, a relief valve, such as relief valve  925  described in reference to  FIG. 13 , may be coupled to fluid port  330  to enable fluid pressure relief and prevent over-pressurization of cylinder  100 . 
         [0052]    Winch  985  may be further configured to allow cable  990  to extend therefrom only when the pressure of fluid within cylinder  100  exceeds a minimum level. As such, the pressure within cylinder  100  may be controlled and remain substantially constant as cylinder  100  extends to its preset limit. By controlling the pressure within cylinder  100  in this manner, cylinder  100  both displaces and supports object  960 . Further, winch  985  eliminates the need for guide  965 , described with reference to  FIG. 11 . 
         [0053]    To operate cylinder  100 , as illustrated by  FIG. 13 , cylinder  100  is moved from its storage location to a location where an object  960  is to be displaced. At the site of operation, cylinder  100  is positioned such that end cap assembly  110 , which includes fluid port  330 , is coupled to a fixed surface  950 . This orientation provides easy access to fluid port  330 , allowing cylinder  100  to be conveniently filled and emptied through port  330 . 
         [0054]    In some embodiments, including those illustrated by  FIG. 13 , fixed surface  950  is the ground, and cylinder  100  is positioned within a bucket-shaped device  995  which is secured to the ground  950  by a spear  945  extending from bucket  995  into the ground  950 , or other equivalent means. Bucket  995  limits translational movement of cylinder  100  relative to ground  950  and prevents toppling of cylinder  100 , perhaps due to wind, as cylinder  100  is operated. 
         [0055]    Object  960  is then positioned on end cap assembly  105  and may be coupled thereto to prevent movement of object  960  as cylinder  100  is inflated and extended. Cylinder  100  may in some embodiments include a lateral support member that extends from the cylinder  100  to the ground  950  to secure the cylinder laterally. One such means is a plurality of guy wires  940  coupled between cylinder  100  and the ground  950 . In order to avoid coupling such guy wires  940  directly to pressure sleeve  115  of cylinder  100 , cylinder  100  includes a fabric loop  935  extending at least in part around its circumference. One or more of guy wires  940  are coupled between fabric loop  935  and ground  950 . 
         [0056]    A fluid source  930  is coupled to fluid port  330 . Fluid source  930  provides fluid to cylinder  100  to inflate and extend cylinder  100 , thereby displacing object  960  to a desired height. In some embodiments, fluid source  930  is an air pump. A check valve and/or pressure relief valve  925  may be disposed between fluid source  930  and fluid port  330  to control fluid flow into/out of cylinder  100  and the pressure of fluid contained therein. 
         [0057]    Once positioned and coupled to fluid source  930 , fluid source  930  may then be activated to fill cylinder  100 . Fluid then flows through fluid port  330  and flowbores  425  ( FIG. 4B ) of collet plug  165  into pressure sleeve  115 . As cylinder  100  is filled, end cap assembly  105 , with object  960  coupled thereto, is displaced. When object  960  is displaced to the desired location or height, filling of cylinder  100  is discontinued. Due to the fluid-tight nature of bladder  140  ( FIG. 1C ) and the ability to add fluid through port  330  as desired or when needed, cylinder  100  may remain in this extended configuration, and object  960  in this displaced position, indefinitely. 
         [0058]    When it is desired to lower object  960 , fluid port  330  is opened. Pressurized fluid contained within cylinder  100  is exhausted from cylinder  100  through port  330  and valve  925  to the atmosphere or to a reclamation system (not shown) coupled thereto for subsequent reuse. Due to the flexible nature of fabric  120  of pressure sleeve  115 , cylinder  100  gradually collapses under its own weight as fluid is exhausted from cylinder  100 . 
         [0059]    To assist cylinder  100  as it collapses, a pump (not shown) may be coupled to valve  925 . The pump may then be activated to provide a partial vacuum on cylinder  100  and thereby assist the collapse of cylinder  100 . Once collapsed and empty, cylinder  100  may be stored in a storage space that is only a fraction of the space occupied by cylinder  100  when filled. Alternatively or additionally, a cord or line may be coupled to cylinder  100  prior to expanding cylinder  100  to displace object  960 . When cylinder  100  is collapsed to lower object  960 , a tension load may be applied to the cord to assist the collapse of cylinder  100 . 
         [0060]    Although pressure sleeve  115  is shown in the figures and described as cylindrically shaped, pressure sleeve  115  may assume other shapes having noncircular cross-sections, such as but not limited to rectangular, square, or oval. Aside from having a noncircular cross-section, construction, assembly and operation of cylinder  100  remains substantially the same as described above. Further, while operation of cylinder  100  is described in the context of displacing an object using a single cylinder  100 , more than one cylinder  100  may be arranged to displace an object. For instance, two or more cylinders  100  may be oriented in series, for example, one stacked on top of the other. The uppermost cylinder  100  would then be inflated to displace the object. When that cylinder  100  is inflated to its maximum length, the adjacent cylinder  100  is next inflated to its maximum length, and so on until the object is displaced to the desired height. Further, two or more cylinders  100  may be arranged side by side to displace a single relatively large and/or heavy object, the size and/or weight of which is beyond the capacity of a single cylinder  100 . In such applications, the two or more cylinders  100  would preferably be inflated at approximately the same rate to uniformly displace the object. 
         [0061]    While various preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings herein. The embodiments herein are exemplary only, and are not limiting. Many variations and modifications of the apparatus disclosed herein are possible and within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.