Abstract:
A lightweight, collapsible, portable, adjustable tubing structure is used upon any conventional bed to lift and support the bed covers above the desired portions of the anatomy of an occupant of the bed. The device may feature multiple adjustments, for example, vertical (height) adjustment and horizontal (width) adjustment. Preferably, all the adjustments are continuous, non-incremental adjustments to best fit the device to a given bed. The device may be made of simple and extremely durable off-the-shelf pieces, preferably of PVC pipe, bushings, tees, and elbows, plus adjustment system that comprise threaded mobs holding a nut and bolt pressure lock system. Other adjustment system may be used, such as pins, clips, fasteners, or other locks or connectors, but the adjustment knob system is most preferred because of its ease, safety, and simplicity. The tubing structure may be used for other purposes wherein a tarp, sheet, or panel is to be supported above an interior space that can house a person(s), plant(s), and/or other objects.

Description:
[0001]    This application claims priority of Provisional Application Ser. No. 60/941,280, filed May 31, 2007, the entire disclosure of which is incorporated herein by this reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an adjustable frame device that includes an invented effective and easy-to-use adjustment mechanism. The adjustable frame device may be used in conjunction with a conventional bed or in other settings, especially those in which a sheet, tarp, or other cover is to be held off of an underlying surface to create an interior space for a person, plants, or other equipment to occupy. 
         [0004]    In bed cover support applications, the frame device may be supported by the box spring and mattress of the bed and is utilized to hold the bed covers above and away from a portion of the anatomy of the occupant of the bed. Use of the invented device will be recognized as extremely practical by those persons engaged in hospital or nursing home work, wherein it is at times desirable to elevate bed covers above the occupant of a bed, and especially above the feet or legs of the occupant of the bed to allow more freedom of movement and to encourage good skin health. The preferred embodiments are made entirely or substantially from off-the-shelf parts and are is adjustable in multiple directions, for convenient and versatile use as a support of bed covers or for other sheets or panels in a variety of environments. 
         [0005]    The preferred embodiment is adapted to be disassembled in multiple ways to form multiple configurations for various purposes. For example, one disassembly method results in a compact configuration for longer-term storage, and another results in a lowered configuration for temporary storage from which it is easy to again set up the frame device for use. 
         [0006]    2. Related Art 
         [0007]    Many bed cover supports have been disclosed in the patent literature, including the following: U.S. Pat. No. 2,244,310 (Murphy); U.S. Pat. No. 2,291,203 (Bent); U.S. Pat. No. 3,317,932 (Gibbons, Sr.); U.S. Pat. No. 3,808,614 (Reinhard); U.S. Pat. No. 4,287,622 (Lane); U.S. Pat. No. 5,329,658 (Fontenot, et. al.); U.S. Pat. No. 6,834,403 B1 (Elliott); U.S. Pat. No. 7,137,159 B1 (Choate); and U.S. Patent Publication #US2005/0273931 A1 (Edwards). 
         [0008]    Still, even in view of the many bed cover supports that have been designed, there is a need for a bed cover support device that is simple, durable, and easily adjustable and usable by a wide variety of people, businesses, and medical or care facilities. The inventor believes that there is a need for such a bed cover support device that may be made entirely or substantially of sturdy and safe off-the-shelf parts that are commercially available, so that the device may be made and repaired economically. There is still a need for an adjustable frame device that is easy to transform into a compact configuration and/or a lowered configuration for long-term or temporary storage. There is still a need for an adjustment mechanism, which may be used in such a frame device or in other frame devices, that is safe, easy, and quick to use, and that may be made from off-the-shelf parts. 
       SUMMARY OF THE INVENTION 
       [0009]    In a first set of embodiments, the invention comprises an adjustable frame device that is adapted to lift bed covers, a tarp, or other sheet or panel structure above an underlying surface, to create an interior space underneath said sheet or panel structure for receiving a person, a part of a person, plants, equipment, or other items that are to be warmed, protected, shielded, or otherwise covered by said sheet or panel structure. In alternative embodiments, the invention is an adjustment mechanism that allows adjustment of the frame in any direction along the length of an elongated frame portion or portions, wherein said elongated frame portion(s) each comprises two tubes that are coaxial and slidable relative to each other unless locked in place relative to each other by said adjustment system. 
         [0010]    In preferred embodiments, the invented frame device is adapted to elevate and support portions of bed covers above the top surface of the bed mattress so that they may be raised above the occupant of the bed to minimize contact and/or pressure from said covers on regions of the occupant&#39;s body. The preferred frame device comprises two foot portions, which are inserted below a mattress, two leg portions that extend upward from the foot portions on each side of the mattress, and an upper support portion that extends transversely preferably all the way across the bed and upon which the covers are placed. Each leg portion may be formed of two telescoping leg members that are adjustably fixed together by the invented adjustment mechanism. There is no requirement for direct attachment of the frame device to the bed frame or to the box spring or mattress, but, instead, the feet of the device are temporarily trapped in-between the box spring and the mattress by means of being slid a significant distance in-between said box spring and mattress. There is no need for any fasteners from the feet to the box spring or to the mattress, and no need for connectors between the feet, especially no connectors that extend between the feet underneath the mattress. 
         [0011]    Preferably, there is an adjustment in the transverse width of the frame device by means of telescoping or other adjustment of the upper support portion to be wider so that, preferably, it has the same width as the bed mattress. Preferably, there are adjustments in the overall height of the device by means of telescoping or other adjustment of the length (height) of the two leg portions. The device is portable, lightweight, and adjustable to fit various sizes of beds and occupants and to adjust for various preferences of the occupant and/or caregiver. The device may be easily assembled and placed into position upon a bed by a single individual without assistance. The device also may be easily disassembled by a single individual, without assistance, to configurations that include: a substantially or entirely disassembled configuration for cleaning and/or sanitizing of the individual parts; a partially disassembled configuration for temporary storage, such as a lowered configuration; and a partially disassembled configuration for transport and longer-term storage, such as a collapsed/folded configuration. The device may be made from plastic tubing and fittings that may be easily disassembled, cleaned and sanitized, and then reassembled, without damage to the materials. 
         [0012]    The preferred device may be constructed from parts that are readily available “off the shelf” items and that are sturdy and very unlikely to be damaged or bent, and very unlikely to become difficult to adjust even after many uses and/or many adjustments. Preferred embodiments may comprise both vertical and horizontal adjustment systems wherein the device may be adapted to any size and shape of bed and/or support virtually any size and shape of sheet or panel. 
         [0013]    The preferred device may be used in cooperation with equipment other than a bed or with sheets or panels other than bed covers. For example, embodiments may be used as a support for a tent, a hunting shelter, camouflage cover, mosquito netting, or other covers or shades. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a perspective view of one embodiment of the invented frame device, in a configuration for use, installed on a bed prior to being covered by bed covers. 
           [0015]      FIG. 2  is a side elevation view of the embodiment of  FIG. 1 , in use with an occupant and bed covers. 
           [0016]      FIG. 3  is a perspective view of the embodiment of  FIGS. 1 and 2 , wherein the two leg members of each leg portion are disconnected from each other to separate the upper support portion from the feet. This disconnection is done by unlocking the preferred adjustment system. 
           [0017]      FIG. 4  is a perspective view of the embodiment of  FIGS. 1-3 , fully assembled in the “in-use” configuration. 
           [0018]      FIG. 5  is a detail, partial perspective view of the preferred adjustment system of the embodiment of  FIGS. 1-4 , said adjustment system circled in  FIG. 4 . 
           [0019]      FIG. 6  is an exploded perspective view of the adjustment system featured in  FIG. 5 . 
           [0020]      FIG. 7  is a cross-sectional elevation view of the adjustment system featured in  FIGS. 5 and 6 . 
           [0021]      FIG. 8  is a disassembled perspective view of an alternative embodiment of the invented frame device, which is the same as that in  FIGS. 1-4  except for each of the upper leg members having an alternative end, that is, an end with improved hand grip features. Portions of the device are shown as separated and/or folded/collapsed for easy storage or transport. The upper and lower leg members of the right and left leg portions are unlocked and separated, with each lower leg member remaining attached to, and foldable against, its respective right or left foot. Further, the left, upper leg member is shown detached from said upper support portion, to indicate that said upper support portion may be stored without its leg members. 
           [0022]      FIG. 9  is a disassembled perspective view according of the embodiment of  FIGS. 1-4  and  8 , wherein the upper leg members are disconnected from the upper support portion and inserted and locked into their respective lower leg members. This way, each entire leg portion (comprising upper and lower leg members) may be folded down against its respective foot. 
           [0023]      FIG. 10A  is a detail, close-up view of one foot portion combined with one leg portion illustrating that the upper leg member may be being slidable substantially all the way down into the lower leg member before locking the upper and lower leg members together, wherein that configuration will result in a very compact combined foot and leg unit for storage. 
           [0024]      FIG. 10B  is a detail, partial cross-section view of the upper end of the upper leg of  FIGS. 8-10A , wherein there is shown in cross-section the handle sleeve provided around the upper end of the leg member. 
           [0025]      FIG. 11  is a perspective view of the embodiment of  FIGS. 1-4 , in short-term storage on a bed, wherein the lower leg members have been detached from the foot portions and left connected and locked, by means of the adjustment system, to the upper leg members. This configuration, wherein the entire leg portions depend from the upper support portion, ensures that no members protrude up from the feet. This partially disassembled configuration lowers the upper support portion to be close to the top of the mattress, and the entire device is temporarily stored in a way that will be out of the way and safe for workers and adjacent patients. 
           [0026]      FIG. 12  is a perspective view of the embodiment of  FIGS. 1-4 , illustrating the device used to support a tent or mosquito netting. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    Referring to the Figures, there are shown several, but not the only, embodiments of the invented frame device, which may be used to elevate and support bed covers (such as sheets, blankets, quilts, comforters, and/or coverlets) or tarps, nets, or other sheets or panels. The term “sheets or panels” is a broad term that includes flexible, semi-rigid, and rigid materials; hereafter and in the claims, the single word “cover” is used to include said sheets and panels including flexible, semi-rigid, and rigid materials. 
         [0028]    The preferred frame device supports said bed covers above the desired portion of the anatomy of an occupant of the bed, or which may be used to support other panels, sheets, tents, netting, or other objects to create an interior space for receiving a part of a person, a person, plants, equipment or other objects. 
         [0029]    Referring now to  FIG. 1 , it will be observed that bed cover frame device  10  may be anchored to the bed for use, by placing portions of the frame device  10  between the box spring  60  and the mattress  62 . The pedestals  12  (or “feet”) may be slid, from their respective sides of the bed, between box spring  60  and mattress  62  of bed  8 . The pedestals  12  are preferably rectangular or square in “footprint” so that they are unlikely to tilt or pivot. The pedestals  12  are sized to extend a distance underneath the mattress  62  that, when combined with the substantial weight of the mattress  62 , is sufficient to retain bed cover frame device  10  in the desired position upon the bed. 
         [0030]    Referring now to  FIG. 2 , it will be observed that when a person P occupies bed  8  with the bed cover frame device  10  in place, bed covers C may be elevated above the desired portion of the anatomy of person P. Note that the frame device  10  is preferably near the foot end of the bed  8 , but may be moved to nearly any position on the bed; the pedestals  12  may be slid underneath the mattress  62  at any place along the length of the mattress (or, for that matter, anywhere along the perimeter of the mattress), so that the frame device  10  may be shifted up and down along the length of the bed to suit the occupant (or, in rare instances even shifted to extend from the head to the foot of the mattress by being slide underneath the mattress at the head and the foot). Typically, the frame device  10  will be used to elevate the covers over the feet, to minimize pressure on the feet and to allow the occupant to easily move and shift his position (for example, to help eliminate “bed sores”), but there may be instances in which elevating and supporting other portions of the bed covers may be beneficial. 
         [0031]    Referring now to  FIGS. 3 and 4 , it will be seen that the preferred bed cover frame device  10  is constructed of a plurality of plastic PVC pipe and fittings, which may be purchased off-the-shelf from PVC piping suppliers. The larger pipes are preferably ¾ inch inside diameter and the smaller pipes are preferably ½ inch inside diameter. At points where a rigid/fixed, permanent connection is desired, appropriate adhesive is used to join the pipes and fittings. At points where a non-permanent connection between pipes and/or fittings is desired (for example, so that disassembly such as in  FIG. 8-11  may be done for lowering, folding, collapsing, transporting, or storing), tight but detachable friction fits are provided without adhesive. At points where it is desired that the smaller pipes be slideably mounted within the larger pipes (for a type of telescoping extendibility), bushings appropriately sized to the outside diameter of the smaller pipes are used; said bushings are rigidly mounted/fixed within the appropriate tee or elbow fittings to allow the smaller pipes to fit snugly but moveably within the larger pipes. 
         [0032]    Bed cover frame device  10  is generally comprised of two lower pedestals (or “feet”)  12 , two leg portions made of vertical stanchions  16  (or lower leg member) and posts  40  (upper leg portions), and upper support structure  34 . Each of the pedestals  12  is generally comprised of a rectangular horizontal tubing structure  14 . Horizontal tubing structure  14  is comprised of three tubes  18  of preferably equal length and two tubes  20  of equal length (but shorter than the length of tubes  18 ). The five aforementioned tubes are rigidly, adhesively affixed to one another using four elbows  22 , for forming a square foot. In each pedestal structure  12 , the tee  24  is mounted snugly upon tubes  20  as shown but is free to rotate upon tubes  20  to allow the pedestal  12  plus leg/leg members to be made as compact as possible when not in use. (See  FIGS. 8 ,  9 , and  10 A). Vertical stanchion  16  is comprised of tube  26  adhesively affixed within tee  24  at its lower end  28  and affixed within tee  32  at its upper end  30 . Within (and/or connected to) tee  32  resides adjustment system  50  (See  FIGS. 5-7 ). 
         [0033]    Upper support structure  34  is generally comprised of right and left tubing structures  36  and  38 , which are examples of right and left U-shaped frames. Right and left tubing structures  36 ,  38  slideably or otherwise adjustably connect to each other to form a rectangular platform that is distanced from the upper surface of the mattress by the foot and leg portions of the device. These right and left tubing structures are adjustable horizontally in relation to one another, for increasing or decreasing the overall width of the device (the longest dimension of the upper structure  34  being called the “width” of the device because it is typically placed parallel to the width of the bed). The upper support structure  34  is generally flat and on a plane across which the bed covers are placed, so that the plane of the upper support structure  34  is parallel but distanced from the upper surface of the bed mattress. At each end of the upper support structure  34  is provided a vertical post  40 , which become the upper leg members of the leg portions. 
         [0034]    Tubing structure  36  is comprised of two ¾ inch tubes  42  and two ¾ inch tubes  20  rigidly, adhesively affixed to one another using elbows  22 . Tee  24  is mounted and fixed to tubes  20 , and post  40  (½ inch diameter) may be rigidly fixed within tee  24  utilizing bushing  44 . Alternatively, the post  40  with its bushing  44  may be slideably removable from the tee  24 , or the post  40  may be removable from bushing  44 . Having the upper end of post  40  (with its bushing  44  or other upper end structure) be removable from the tee  24  (for example, see  FIGS. 8-10A  and B) allows post  40  to be removed from the upper support structure for disassembly and storage or transport. The lower end of post  40  is designed to be inserted within stanchion  16  (lower leg member) at the upper end of tee  32 , wherein bushing  31 , having an inside diameter sufficient to accept the outside diameter of post  40 , is rigidly secured. Rigidly affixed at the inner ends of tubes  42  are tees  32  containing adjusting systems  50 . (See  FIGS. 5-7 ). 
         [0035]    Tubing structure  38  (the tubing structure toward the left in  FIG. 3 ) is, in effect, a mirror image of the right tubing structure  36  (except that the inner ends of tubes  46  cooperate with the adjusting system  50  fixed to right tubing structure tubes  42 ). Upper tubing structure  38  is comprised of two ½ inch tubes  46  and two ¾ inch tubes  20 , rigidly and adhesively secured to one another using elbows  22  and bushings  44  at elbows  22  where end  47  of tubes  46  are joined. Vertical post  40  is mounted as described above for tubing structure  36 , preferably by being slideably and removably inserted into tee  24 . Ends  48  of tubes  46  slide through bushings  31  secured within tees  32  (of the adjustment system  50  of upper structure  34 ) and, hence, within tubes  42  of tubing structure  36 . 
         [0036]      FIG. 4  illustrates the preferred frame device to best advantage, as it is configured when ready for use after being adjusted in width to its minimum width. 
         [0037]    Referring now to  FIGS. 5 ,  6  and  7 , adjustment system  50  is detailed, wherein said adjustment system  50  is preferably the same or similar in each of the locations on the frame device  10  where is it provided (that is, both for width adjustment and for height adjustment). Thus, ½ inch tubes  40  or  46  may be slideably adjusted and secured within ¾ inch tubes  26  or  42 . Adjustment system  50  is preferably comprised of knob  52  comprising on one end a threaded portion  54  that mates with threads  33  within tee  32 . Bolt  56  and nut  58  are secured within/on knob  52 , via the bolt  56  extending through the knob  52  and the nut being threaded tightly onto the threaded end of the bolt to anchor/lock the bolt to/through the knob. When the nut is tightened to anchor/lock the bolt to/through the knob, the distal end of the bolt may protrude out beyond the distal end of the nut. The distal ends of the bolt and the nut are the ends that are facing generally toward the center of the tee. When knob  52  is threaded within tee  32 , the distal end surface(s) of the nut  58  and/or of bolt  56  contact(s)/abut(s) against the outside diameter of the ½ inch tubes  40  or  46 , wherein turning/screwing the assembly  50  farther into the tee  32  serves to force the nut and/or bolt distal end surfaces more forcefully against the tube  40 / 46 , in a manner similar to a set screw, to firmly lock the adjustment system. 
         [0038]    Note that, in  FIG. 7 , the distal end surface of the nut  58  is portrayed to be the member that abuts against the tube  40  to keep the tube  40  from sliding relative to tube  26 . Alternatively, it may be more likely (depending on the bolt length relative to the knob axis length) that the bolt distal end surface (when the nut is tightened against the end surface of the threaded portion  54 ) is the surface that will abut against the tube to keep tube  40  from sliding relative to tube  26 , tee  32 , and bushings  31 . In other words, the bolt distal end surface is expected, in many embodiments, to protrude beyond the distal end surface of the nut, and so, is expected to be the abutment surface for the adjustment system  50 . This may be preferred as the substantially flat and broad distal end surface of the bolt may provide more and less damaging abutment surface for locking the tube  40  relative to tube  26 , tee  32 , and bushings  31 . In yet other embodiments, both the bolt distal end surface and the nut distal end surface may be coplanar or substantially co-planar and may both be abutment surfaces that abut into the tube  40 . In either configuration, the abutment member immovably connects tube  40  to  46  within tee  32  at the appropriately adjusted position, and the abutment member preferably does not gouge into the tube  40  or otherwise significantly mar the tube  40 . 
         [0039]    Because of the firm and sure abutment of the abutment surface against the tube, the system  50  holds the device firmed in each adjusted position, and may be considered a “lock” or “latch.” To change the width or length adjustment of the device, knob(s)  52  is/are loosened slightly, whereupon the bolt (and/or nut, as discussed above) move slightly away from tubes  40  or  46 , freeing tubes  40 / 46  to be moved within tees  32  to a different position. When the desired position is attained, knob(s)  52  is/are tightened so that the bolt (or nut) end(s) again abut against tubes  40  or  46  to lock the tubes  40 / 46  in the newly-adjusted position. Adjustment system  50  allows continuous, rather than incremental, adjustment of the length of a frame piece that is made of two coaxial tubes that are slidable relative to each other along the co-axis. 
         [0040]    Referring now to  FIG. 8 , it will be seen that portions of the bed cover frame device  10  may be separated, and/or portions may be rotated with respect to one another, to allow the structure to be made as compact as possible for storage or transport. Each of the stanchions  16  may be rotated downwardly relative to each respective foot/pedestal  12  by rotating tee  24  upon tubes  20 . 
         [0041]    Further, as portrayed in  FIGS. 8 and 9  to best advantage, the posts  40  (preferably with whatever bushing, sleeve, or other structure is provided on the upper end of post  40 ) may be removed from their respective tees  24 . Thus, posts  40  could be removed from the upper structures  36 ,  38  and stored side-by-side with the other parts, or more preferably, stored inside the lower leg members (stanchions  16 ). The posts  40  may be slid into the stanchions, and locked in the stanchions by tightening the adjustment systems  50  on the stanchions  16 .  FIGS. 9 and 10A  further illustrate the preferred storage configuration for the leg portions, wherein the posts  40  (upper leg members) are inside the stanchions  16  (lower leg members), and said posts may be slid substantially inside the stanchions. The upper ends of the posts  40  are enlarged compared to the rest of the post  40  structure, and so said upper ends will prevent the entire posts from sliding into the stanchions. 
         [0042]      FIG. 10B  illustrates in detail one alternative upper end for posts  40 , wherein a short extension  144  protrudes as the uppermost end, and said extension  144  is attached to and held by sleeve  244  that surrounds the upper end of bushing  44 . The short extension  144  slides into the tee  24  of the upper support structure  34 , and the sleeve  244  provides a relatively large diameter handle for the user to grasp and rotate, if needed, to detach posts  40  from the upper support structure  34 . 
         [0043]    The methods of disassembling the frame device  10  shown in  FIGS. 8-10A  allow the device  10  to be transported and stored in a compact shape, wherein each foot and leg combination is separate from the upper, rectangular support structure  34 , and the each foot and leg combination is folded to be quite flat, that is, to have the leg be generally co-planar with its respective foot. 
         [0044]    Referring now to  FIG. 11 , there is a shown a “lowered” configuration wherein the upper support structure  34  is lowered to the top of the bed by means of detachment of the leg portions (combined stanchion  16  and post  40 ) from the feet  12 . By lowering the support structure  34  to the bed (with leg portions attached) and by leaving the feet  12  in between the springs and mattress, the entire device  10  is close to surfaces of the bed and not protruding upward to become a potential danger or an inconvenience when not in use. Also, by leaving the feet in between the springs and mattress, the stanchions  16  may be quickly reattached to the feet without lifting or moving the feet or the mattress, and the device  10  may be quickly placed in use again. 
         [0045]      FIG. 12  illustrates an alternate environment in which the frame device  10  may be used, namely, to frame device a camping tent or mosquito net  70  for use in sleeping outdoors. The illustrated net  70  comprises a weighted perimeter edge to keep the net edge on the ground. Further, weights or other securement devices (not shown) might be used to stabilize the pedestals  12  on the ground in the event that the pedestals  12  are placed on the top surface of the ground. 
         [0046]    The terminology of “horizontal” and “vertical” are not meant to necessarily be limiting, but are merely used for convenience to clarify preferred relationships of the parts of the device and preferred relationships of the device to the bed. Other orientations of the device to the bed or to other objects it holds may be included in the invention. 
         [0047]    It may be noted that the tee, locking bolt, nut, and knob (herein also referred to as “the tee and lock,” for simplicity) of the adjustment system  50  is shown on particular ones of the U-shaped frames of the upper support structures (on the right U-shaped frame in  FIG. 3 ), and on the lower leg members rather than the upper leg members. The tee and lock may be placed instead on the other U-shaped frames (the left U-shaped frame, in  FIG. 3 ), or, less preferably, one tee and lock may be placed on each of the right and the left U-shaped frames. Likewise, the tee and lock may be placed on the upper leg members, rather than the lower leg members, or, less preferably, one tee and lock may be placed on each of the upper and lower leg members. 
         [0048]    Alternative embodiments of the invention comprise the invented adjustment system  50  in other frame devices and/or on other elongated tubes. For example, one or more adjustment systems  50  may be used to slideably connect and lock many embodiments of coaxial tubes that are parts of simple or complex frame devices. Multiple adjustment systems  50  may be placed, as in the preferred embodiments, on both sides of a rectangular or otherwise-shaped frame to allow ends of the frame to be widened or lengthened. Or, individual tubes may be adjusted in length using the system  50 . While the terms “tube” and “tubes” is used herein and in the claims, it may be noted that it is the outer member of the coaxial, slidable, adjustable connection that should be hollow to allow slidable insertion of the inner member. The inner member, while also described as a tube, may alternatively be solid. A solid inner member, however, may perhaps unnecessarily add to the weight of the frame, and so the inner member may also be described as a cylindrical inner member or an elongated inner member. Further, both outer and inner members may be other than cylindrical, for example, a square (in transverse cross-section) outer tube and a square (in transverse cross-section) inner member. In such embodiments, the abutment member distal surface of the adjustment system preferably abuts against a flat side of the inner member. 
         [0049]    Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the broad scope of the following claims.