You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is related to U.S. provisional patent application serial No. 60/361,671 filed Mar. 4, 2002. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention pertains generally to industrial curtains used as environmental closures for openings through which traffic can still pass. The curtains generally comprise a plurality of usually transparent strips that are suspended contiguously to each other from a hanger or support generally fixed adjacent to a top margin of the opening. Each of the strips usually consists of a length of flexible, generally transparent, material terminating adjacent to a lower margin of the opening. The present invention relates particularly to an improved support from which the industrial strip curtain can be suspended.  
           [0003]    Industrial curtains are conventionally employed to provide closures between, for example, separate manufacturing areas within large buildings, warehouses and the like. Goods are often required to be transported from one area of a manufacturing or storage facility to another where one or the other of the areas is heated, air-conditioned or even refrigerated. Sometime other environmental concerns need to be addressed such as dust, fumes, smoke, dirt, or even noise. Where the traffic is only occasional, conventional doors can be employed to close any doorway between the two areas. Where the traffic is considerable, the use of conventional doors gives way to suspended flexible screens or curtains, which inhibit the wholesale transfer of air from one area to the other yet still permit goods-transporting vehicles to pass through with little effort.  
           [0004]    These curtains are generally made up of side-by-side elongated plastic strips that hang from a support system mounted to extend across the top of the opening. For safety reasons, it is desirable that the curtain be sufficiently transparent that one operating a transporting vehicle be able to see any hazard or obstruction that might exist on an opposite side of a curtain before proceeding through. Persons on the opposite side of a curtain also desire to be able to see oncoming transport vehicles so appropriate evasive action can be taken. Thus, plastic materials, which were more or less transparent, such as polyvinyl chloride and polyethylene, were adopted as the preferred materials for forming such screens as shown, for example, in U.S. Pat. Nos. 4,095,642, 4,165,778, 4,232,725, and 4,607,678.  
           [0005]    Many different support systems have been developed for these strip curtains. One type of support system involves each strip forming the curtain having a loop for receiving a horizontal rod that is mounted adjacent to the top of the opening covered by the curtain by two or more brackets. Examples of this type of support system are disclosed in U.S. Pat. Nos. 4,095,642; 4,384,606; 4,515,202; and 6,213,437. A related type of support system is disclosed in U.S. Pat. Nos. 4,257,471 and 4,776,382 wherein the loops at the top of each strip are formed by separate structural hangers that loop over the horizontal rod and are coupled to each strip forming the curtain. A common disadvantage of such support systems is the tendency for the horizontal rod to sag between supports, which can cause an uneven hang to the strips forming the curtain.  
           [0006]    To avoid this disadvantage, some much more complicated hanger schemes have been devised as shown in U.S. Pat. Nos. 4,312,396; 4,335,777; 4,340,106; 4,388,961; 5,146,971; 5,520,237; and 6,050,322 that commonly use extruded profiles or similar structures that are secured adjacent to the top of the opening to be covered by the curtain. The extruded profiles are design to mate with other formed hanger members coupled to the strips forming the curtain. None of these systems have gained wide acceptance, perhaps due to the time involved in assembly of the curtain strips to the hangers and the occasionally awkward engagement between the hangers and the supporting profiles or equivalent structures. Much more simple structures are to be found in U.S. Pat. Nos. 4,165,778; 4,232,725, 4,289,190; and 4,607,678 that disclose a series of threaded fasteners such as a bolts or the like penetrating a series of holes located in the upper ends of each strip. Mating fasteners are engaged on the bolts over the strips to hold the strips in place. The assembly of such structures has been found to be a very time-consuming, repetitive activity, which is often not completed in an entirely satisfactory way, thus leading to later disengagement by the mating fasteners causing the strips to fall away from the support system.  
           [0007]    A strip curtain support system that permits fast and easy assembly is disclosed in U.S. Pat. No. 5,127,460. The support comprises a bar having a series of pegs spaced equidistance from each other along the length of the bar. Each peg includes a leg extending substantially perpendicularly outward from the bar. A foot is fixed to each leg so that each foot extends downwardly perpendicular to the stalk and is spaced from the bar. The strips forming the curtain have multiple holes near the top of each strip, which are spaced the same distance from each other as the distance between the pegs. The strips can be suspended from a plurality of the pegs by manipulating the multiple holes upward over the feet and onto the leg portion of each peg. Unfortunately, the downwardly projecting portion of each foot acts, over time, as a lever pressed by the moving curtain that flexes the base of each leg adjacent to the strip upward and downward to such an extent that the support fails by the leg breaking away from the supporting bar.  
           [0008]    Accordingly, what is needed is a strong strip curtain support system that allows for fast and easy assembly, yet is sufficiently strong that product failure due to flexing or any other action is unlikely to occur. What is further needed is such a strip curtain support system that permits the curtain strips to be easily changed when the strips become worn or abraded, or for other reasons need moved.  
         SUMMARY OF THE INVENTION  
         [0009]    A strip curtain support of the present invention is intended for use in an environmental strip curtain system that is typically employed for at least partially obstructing a passage through a wall. The strip curtain generally has a plurality of flexible transparent strips suspended for the curtain support. Each strip of the curtain includes a plurality of holes of a selected size located adjacent to an upper end of the strip. The strip curtain support of the present invention can include a bar, and mounting elements for mounting the bar to fixed structure adjacent to the passage to be obstructed by the curtain. The mounting elements can be in the form of fasteners adapted to pass through holes or slots in the bar to fasten the bar to the wall or ceiling above the passage. The strip curtain support also includes a plurality of pegs that can be coupled to the bar. Each peg includes an outwardly extending stalk portion that can extend outwardly from the bar. The stalk portion of each peg is generally linear and perpendicular to the bar, however in some circumstances the stalks can be curved so long as the stalks are generally parallel to each other and curve in the same direction and to the same extent. The stalks generally include a curved upper surface. The curved upper surface can form a portion of a cylindrical stalk or tapered stalk.  
           [0010]    Each stalk has a proximal end typically connected to the bar and a distal end including a cap spaced by a pre-selected distance from the proximal end of each stalk. The proximal end of each stalk can be fixed to the bar by fastening, swaging, welding, casting or molding. The proximal end of each stalk can also be directly fixed to a supporting surface by fastening with either a separate or an integral fastener, in which case the bar can be omitted. Alternatively, the proximal end of each stalk can be received in a slot in bar that can provide for some small variation in alignment of the holes in the strips, or allow for gravitational alignment of the strips even when the bar is not mounted to a supporting surface in a true horizontal manner. When the bar includes a series of slots to receive the proximal ends of the stalks, the slots can include an upper portion that is larger is size than a lowest portion to allow for insertion of the pegs during assembly. In a preferred embodiment each slot includes an angular path between the larger sized portion and the lowest portion so that displacement of the pegs from the slots while a curtain is suspended thereon is rendered nearly impossible.  
           [0011]    Each cap, which is located on the distal end of a stalk, is generally symmetric with respect to the stalk to which the cap is fixed. An outermost edge of the cap ranges from ovate to a circle having an outer maximum dimension or diameter greater than the diameter of the holes in the strip to be mounted on the strip curtain support. The diameter of the outermost edge of the cap can be from about 1.2 to about 1.7 times the diameter of the holes in the strip, and is preferably about 1.5 times the diameter of the holes in the strip. The diameter of the stalk generally approximates the diameter of the holes in the strip, although some variation in size will not prevent the combination of the strip curtain and the support from performing satisfactorily.  
           [0012]    A distal outer surface of the cap has a shape facilitating the stretching of the holes of each strip to a size sufficient to permit the strip to be forced over the outermost edge of the cap. In a preferred embodiment, the distal outer surface of each cap comprises a substantially conical surface extending from a distal extremity of the cap to the outermost edge of the cap. Alternative embodiments for the distal outer surface of each cap include a mushroom-shape and can include a substantially hemispherical shape extending from a distal extremity of the cap to the outermost edge of the cap.  
           [0013]    A proximal surface of the cap extending between the outermost edge of the cap and the stalk to which the cap is fixed is resistant to removal of the strip curtain from the curtain support under normal usage. The proximal surface of the cap can be planar and perpendicular to the stalk, but preferably includes a smooth outer edge to prevent a cutting action on the curtain strips. The proximal surface can also be concave, but is preferably slightly convex. The proximal surface of each cap is spaced from the supporting bar by a distance at least equal to twice the thickness of the strips to be mounted on the curtain support. Preferably, the proximal surface of each cap is spaced from the supporting bar by a distance equal to about five times the thickness of the strips.  
           [0014]    One feature of the present invention is an environmental strip curtain system that allows for easy installation of the strips by providing distal surfaces on the peg caps causing a temporary stretching of the material forming the strips immediately surrounding each hole provided at the upper end of the strips. Thus, the curtain strips can be mounted to the pegs on the curtain support by merely pushing the strips onto the pegs with sufficient force to cause the necessary stretching of the material forming the strips.  
           [0015]    Another feature of the present invention is an environmental strip curtain system which inhibits any accidental removal of the strips, yet allows for easy replacement of one or more strips by providing caps that are integral with the stalks, rather than screw fasteners that can loosen when subjected to normal vibration and jarring, and by providing proximal surfaces to the caps that do not encourage displacement of the strips past the caps, yet permit replacement of the strips by merely pulling on the strips with sufficient force to again stretch the material forming the strips enough to allow the cap to pass through the holes formed in the strips. By selecting the cap size and hole size appropriately, assuming a known make-up of the materials forming the strips, the removal force can be chosen to be in a range that will realistically prevent any accidental strip removal during normal use.  
           [0016]    Additional features and advantages of an environmental strip curtain support system of the present invention will become apparent to those skilled in the art from a consideration of the following discussion of preferred embodiments of the present invention that include the best mode of carrying out the invention as present perceived. The following discussion references the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a perspective view of an environmental strip curtain system that can employ a curtain supporting structure of the present invention.  
         [0018]    [0018]FIG. 2 is a front elevation view of a first embodiment of the present invention.  
         [0019]    [0019]FIG. 3 is a sectional view of the embodiment shown in FIG. 2 taken along line  3 - 3 .  
         [0020]    [0020]FIG. 4 is a front elevation view of a second embodiment of the present invention.  
         [0021]    [0021]FIG. 4A is a front elevation view of a variation on the second embodiment of the present invention.  
         [0022]    [0022]FIG. 5 is a sectional view of the embodiment shown in FIG. 4 taken along line  5 - 5 .  
         [0023]    [0023]FIG. 5A is an end elevation view of the variation shown in FIG. 4A taken from the left end of FIG. 4A.  
         [0024]    [0024]FIG. 5B is a back elevation view of an end portion of the variation shown in FIGS. 4A and 5A.  
         [0025]    [0025]FIG. 6 is a front elevation view of a third embodiment of the present invention.  
         [0026]    [0026]FIG. 7 is a sectional view of the embodiment shown in FIG. 6 taken along line  7 - 7 .  
         [0027]    [0027]FIG. 8 is a front elevation view of a fourth embodiment of the present invention.  
         [0028]    [0028]FIG. 9 is a sectional view of the embodiment shown in FIG. 8 taken along line  9 - 9 .  
         [0029]    [0029]FIG. 10 is a side elevation view of a peg suitable for use in various embodiments of the present invention.  
         [0030]    [0030]FIG. 11 is a side elevation view of another peg suitable for use in various embodiments of the present invention.  
         [0031]    [0031]FIG. 12 is a side elevation view of yet another peg suitable for use in various embodiments of the present invention.  
         [0032]    [0032]FIG. 13 is a front elevation of a bar suitable for use in the present invention.  
         [0033]    [0033]FIG. 14 is a front elevation of another bar suitable for use in the present invention.  
         [0034]    [0034]FIG. 15 is a side elevation of a peg suitable for use in connection with the bars shown in FIGS. 13 and 14.  
         [0035]    [0035]FIG. 16 is a rear elevation of a combination of a peg with another bar.  
         [0036]    [0036]FIG. 17 is a sectional view of FIG. 16 taken through line  17 - 17 .  
         [0037]    [0037]FIG. 18 is a sectional view similar to FIG. 17 of another peg and bar combination.  
         [0038]    [0038]FIG. 19 is a sectional view similar to FIG. 17 of another peg and bar combination.  
         [0039]    [0039]FIG. 20 is an exploded perspective view of another embodiment prior to assembly of the peg to the bar.  
         [0040]    [0040]FIG. 21 is an exploded view partially in section of the assembly shown in FIG. 20.  
         [0041]    [0041]FIG. 22 is a view partially in section of the assembly shown in FIG. 21 immediately after assembly.  
         [0042]    [0042]FIG. 23 is a view similar to FIG. 22 after rotation of the peg with respect to the bar.  
         [0043]    [0043]FIG. 24 is a rear elevation view of the assembly shown in FIG. 23 taken in the direction of arrows on line  24 - 24 .  
         [0044]    [0044]FIG. 25 is a rear elevation view similar to FIG. 24 upon application of a load such as a curtain strip. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0045]    [0045]FIG. 1 shows a perspective view of an environmental strip curtain system  20  that incorporates a curtain holding apparatus  22  of the present invention. The curtain holding apparatus  22  is fixed adjacent a passage  23  through a wall  24 . The strip curtain system  20  includes a strip curtain  26  consisting essentially of a plurality of flexible transparent strips  28 , each strip of width W and length L suspended on the curtain holding apparatus  22  of the present invention, usually in an overlapping pattern. The strips  28  are sufficiently flexible that transportation vehicles  30  can move through the passage  23  through wall  24  by displacing the strips  28  as shown in FIG. 1. The general nature and use of such environmental curtain systems  20  are well known, and the present invention is directed at the new curtain holding apparatus  22  upon which the strips  28  are suspended so as to at least partially obstruct the passage  23  through wall  24 .  
         [0046]    A first embodiment of the curtain holding apparatus  22  of the present invention is shown in FIGS. 2 and 3 to comprise an inverted L-shaped member  32  having an upper, generally horizontal portion  34  and a lower, vertical portion  36 , which are shown to be made of a molded plastic. The upper portion  34  includes openings  38  while the lower portion  36  includes openings  40 . The openings  38  and  40  are suitable to receive bolts, screws, or other fasteners for fastening the curtain holding apparatus  22  to the wall  24  or other fixed structure adjacent to a passage  23  sought to be protected by a strip curtain system  20 . The bar  32  has a lower margin  42  that includes a series of downward projections  44 . A peg  46  is fixed to a front surface  51  of the downward projection  44  and projects outward from the downward portion  36  in a nearly horizontal relationship that is substantially parallel to the upper portion  34 . The peg  46  includes a stalk portion  48  and a cap portion  50 . The stalk portion  48  is shown to be tapered but is otherwise circular in cross-section. The cap  50  is also shown to be tapered but in the reverse direction from the taper shown on stalk portion  48  and is shown in FIG. 2 to be essentially ovate or elliptical.  
         [0047]    A representative strip  28  is also shown in cross-section in FIG. 3 to include a hole  52  near the upper margin  54  of the strip. As will be noted, the size of the hole  52  is approximately the same as the size of the stalk  48  and smaller than the largest dimension of the cap portion  50 . The strip  28  can be installed on peg  46  by pushing the strip  28  over the cap portion  50  with sufficient force as to elastically deform the hole  52 . The cap  50  includes a distal surface  56  that is tapered to facilitate the stretching of the hole  52  to a size sufficient to permit the strip  28  to be forced over the outermost edge  58  of the cap  50  and onto the stalk  48  where the hole  52  elastically returns to its original size. The more abrupt character of the essentially perpendicular proximal surface  60  of cap  50  inhibits the reverse process from occurring under the conditions normally prevalent during use of a strip curtain  26  as an environmental barrier in a passageway or doorway  23  through a wall  24 .  
         [0048]    A second embodiment of a curtain holding apparatus  22  of the present invention is shown in FIGS. 4 and 5 to be a unitary cast or molded work piece, which can be made of a variety of high strength polymers such as a polyacetal, ABS, PEEK, polyamide, and others. In this second embodiment, the lower vertical portion  36  is shown to have a continuous, linear lower margin  42  and a continuous linear upper margin  41 . The upper horizontal portion  34  is shown as merely a short segment joined to the lower vertical portion  36  by webs  35  extending from the front surface  51  to the lower surface  53  of the upper horizontal portion  34  that reinforce the angular relationship between the upper portion  34  and lower portion  36 . The pegs  46  are shown to include an outermost edge  58  that is circular. The distal surface  56  of cap  50  is essentially a truncated cone extending forward from the outermost edge  58  to a distal end portion  62 . A variation of this second embodiment is shown in FIGS. 4A, 5A and  5 B. A first end  43  of the lower vertical portion  36 , shown in FIG. 4A, includes a projecting tab  39  that projects from a rearward portion of the lower vertical portion  36 . An opposite or second end  37  of the lower vertical portion  36  includes a slot  33  in the rear surface  31  of bar  32 , the slot  33  being sized and shaped to receive a similar tab  39  of an adjacent bar  32 . While the shape of the tab  39  and slot  33  are shown to be generally trapezoidal, the exact shape is subject to some choice of design and need not be as illustrated. The cooperating tab  39  and slot  33 , taken together with the surfaces of the ends  43  and  37  operate to align adjacent bars  32  with each other. It will be appreciated that the bars  32  can be of any convenient length, and the lengths of all bars  32  need not be identical.  
         [0049]    [0049]FIGS. 6 and 7 show yet another embodiment of a curtain holding apparatus of the present invention wherein the bar  32  is formed of an extruded aluminum. A series of openings  45  are formed in the lower, vertical portion  36  which are sized to receive a base  64  of peg  46 . The base  64  of each peg is swaged into the opening  45  so that the peg  46  is fixed with respect to the lower, vertical portion  36 . Openings similar to openings  38  and  40  shown in the prior embodiments can be included in the portions  36  and  34  of the bar  32  so that the bar can be secured to either a wall or an overhead fixed structure. The outermost edge  58  of the cap  50  is sized to pass through the opening  45  prior to the swaging operation.  
         [0050]    Yet another embodiment of the curtain holding apparatus  22  of the present invention is shown in FIGS. 8 and 9 and are similar in construction to that shown in FIGS. 6 and 7, however, the lower vertical portion  36  of bar  32  includes an offset portion  66 . The offset portion  66  permits a more substantial base  64  to be employed to support the peg  46 . The margin of base  64  is shown in FIG. 8 in phantom to be rectangular. The outermost edge  58  of the cap  50  to be oval or elliptical with the larger dimension being about the same size as the opening  45  while the smaller dimension is much closer to the diameter of the stalk portion  48 . While the base  64  can be secured through a swaging operation, the more substantial base  64  also permits the base  64  to be welded to the vertical portion  32 .  
         [0051]    [0051]FIGS. 10 through 12 illustrate in detail three embodiments for the pegs usable in bars of the present invention. Each of the pegs is shown to include a base  64 . A stepped portion  68  is sized to be received in an opening  45  in the bar  32 . The embodiments shown in FIGS. 10 and 11 are suitable for use, for example, in the bar  22  shown in FIGS. 8 and 9. The embodiment shown in FIG. 12 can also be used in the bar  32  shown in FIGS. 8 and 9, but with the bar  32  re-oriented so that the openings  45  are in the upper horizontal portion  34  rather than the vertical lower portion  36 . The pegs  46  of FIG. 12 can also be used in strictly a linear bar adapted to be fixed to a ceiling or overhead margin of an passageway  23  thereby eliminating the need for any lower vertical portion  36 .  
         [0052]    The pegs  46  of FIGS. 10 through 12 all include a stalk portion  40 , which is smaller than the outermost edge  58  of the corresponding cap  50 . The cap  50  shown in FIG. 10 includes a proximal surface  60  that is convex while the proximal surface  60  of the embodiment shown in FIG. 11 is concave. The proximal surface  60  in FIG. 12 is formed by a linear taper. The distal surface  56  of FIGS. 11 and 12 have a rounded taper similar to a mushroom cap and can be thought of semi-elliptical in cross-section. The distal surface  56  of FIG. 10 is substantially conical with an apex angle a of the cone being approximately 500.  
         [0053]    Two further embodiments of a bar  32  suitable for use in a curtain holding apparatus of the present invention are shown in FIGS. 13 and 14. The bars  32  include openings  45  that have a larger upper portion  47  and a smaller lower portion  49  situated below the offset  66  as shown in FIG. 9. The embodiment shown in FIG. 13, the larger upper portion  47  is shown laterally offset with respect to the lower portion  49 . The bars  32  shown in FIGS. 13 and 14 also include the mounting openings  38  and  40  as previously discussed with respect to FIGS. 2 through 9.  
         [0054]    [0054]FIG. 15 shows a peg  46  that is suitable for use in connection with the bars shown in FIGS. 13 and 14. The peg  46  of FIG. 15 includes a base  64  including a pair of flanges  70  and  72  separated by a slot  71 . The rearmost flange  70  is dimension to as to be received in the larger portion  47  of opening  45 . The trunk portion  74  between flange  70  and  72  is dimensioned to be received in the smaller lower portion  49  of opening  45  with flange  70  located on one side of bar  32  while flange  72  is located on the opposite side of bar  32 . The peg  46  can be inserted in bar  32  so that it projects parallel to the upper portion  34  of the bar similar to that shown in FIG. 9. Alternatively, it can be inserted oppositely so that it projects away from the upper portion  34  of bar  32 . This freedom of insertion of the pegs  46  is shown in FIG. 15 into the bars  32  shown in FIGS. 13 and 14 allows for accommodation of a wider variety of suspension circumstances that may be present in various curtain installation situations. The ability of the pegs  46  to move within the lower portions  49  of the openings  45  further allows for some minor variances in installation that may avoid any warping of the strips  28  forming the curtain  26 .  
         [0055]    [0055]FIGS. 16 and 17 show another embodiment wherein the lower vertical portion  36  of the bar  32  includes a series of round openings  45 . The peg  46  of FIGS. 16 and 17 includes a base  64  including a flange  72  spaced from a slot  76  by a distance approximately equal to the thickness of the bar  32 . The base  64  is sized to be received in one of the openings  45  while the flange  72  abuts the front surface  51  of the bar  32 . The slot  76  is dimensioned to receive a snap ring  78  adjacent to the rear surface  31  of the bar  32  while flange  72  is located on the opposite side of bar  32 , thus securing the peg  46  to the lower vertical portion  36  of the bar. The peg  46  includes a stalk portion  48  extending forward from the flange  72  and a cap portion  50 , which is essentially a truncated cone extending forward from the outermost edge  58  to a distal end portion  62 . The openings  38  in the upper portion  34  of the bar  32  are intended to be used to mount the bar  32  to a wall or other fixed structure adjacent to a passage sought to be protected by a strip curtain.  
         [0056]    [0056]FIG. 18 shows another embodiment wherein the peg  46  includes a root portion  64  that includes screw threads  80 . The openings  45  in the lower vertical portion  36  of the bar  32  can also include threads, or can be sized so that the insertion of the root portion  64  into the opening  45  forms threads, that conform to the threads  80  on the root portion  64 . The peg  46  includes a flange  72  that abuts the front surface  51  of the lower vertical portion  36  when the threads  80  are fully engaged in the opening  45 . The peg  46  includes a stalk portion  48  extending forward from the flange  72  and a cap portion  50 , which is essentially a truncated cone extending forward from the outermost edge  58  to a distal end portion  62 . A slot  82  is included in the distal end portion  62  of the peg  46  for receiving a driving tool for mounting the peg  46  to the bar  32 . The flange  72  can also include flats  84  to facilitate use of a wrench or other tool to tighten the threads  80  in the opening  45 . The peg  46  of this embodiment can be used with threaded anchors or other hole lining elements, not shown, to mount the peg  46  directly to a supporting structure adjacent to a passage through a wall, entirely omitting the use of a bar  32 .  
         [0057]    [0057]FIG. 19 shows yet another embodiment wherein the peg  46  comprises a flange  72  that abuts the front surface  51  of the lower vertical portion  36 . The peg  46  includes a stalk portion  48  extending forward from the flange  72  and a cap portion  50 , which is essentially a truncated cone extending forward from the outermost edge  58  to a distal end portion  62 . An opening  86  extends axially through the peg  46  and includes a shoulder  88 . A fastener  90 , shown to have the form of a machine screw, extends through the axial opening  86  and has a head  92  that engages the shoulder  88 . The fastener  90  can engage a threaded surface in opening  45 , or more preferably engages a separate threaded nut  94  positioned against or secured to the rear surface  31  of the lower vertical portion  36 . It will be appreciated that the design of the fastener  90  is subject to variation and can include a self taping screw thread or other thread that would permit direct mounting the peg  46  directly to a supporting structure adjacent to a passage through a wall, entirely omitting the use of a bar  32 , with or without the use of separate anchors or hole liners.  
         [0058]    [0058]FIGS. 20 through 25 show an embodiment wherein the openings  45  in the lower vertical portion  36  of the bar  32  are elongated or ovate. A peg  46  according to this embodiment is formed to include a rear flange  70  having a periphery  73  generally matching the shape of the opening  45 , although somewhat smaller to permit the rear flange  70  to be inserted into the opening  45  as shown by the action between FIGS. 21 and 22. A forward flange  72  is provided that is generally larger than the opening  45  and includes a periphery having flats  84  that enable the peg  46  to be manipulated with a wrench or similar tool. The peg  46  includes a stalk portion  48  extending forward from the flange  72  and a cap portion  50 , which is essentially a truncated cone extending forward from the outermost edge  58  to a distal end portion  62 . The distal end portion  62  of the cap  50  can include one or more slots as disclosed in relation to FIG. 18.  
         [0059]    As shown in FIG. 21, the rear flange  70  and forward flange  72  are separated by a distance S about equal to or slightly smaller than the thickness T of the lower vertical portion  36  of the bar  32 . The trunk portion  74  between the two flanges  70  and  72  has a diameter no greater than the width of the rear flange  70 . A forward surface  77  of the rear flange  70  includes inclined surfaces  75  that facilitate initial engagement of the rear flange  70  with the rear surface  31  of the bar  32 , as shown in the series of FIGS. 22 through 24. Rotation of the peg  46  beyond the point of initial engagement, through application of a rotational torque to the flats  84  on forward flange  72 , causes the flanges  72  and  74  to tighten on the opposing surfaces  31  and  51  of the lower vertical portion  36 , thereby securing the peg  46  to the bar  32  as shown in FIGS. 23 and 24. Once being secured in place, the load of the strip curtain  26  under the force of gravity, coupled with the vibration that will occasionally occur as vehicles and people pass through the curtain  26 , will have the tendency to lower the trunk portion  74  within the opening  45  to the position shown in FIG. 25 so that removal of the peg due merely to forces on the curtain  26  is nearly impossible The peg  46  of FIGS. 20 through 25 can be injection molded from a high strength plastic such a polyacetal, ABS, PEEK, polyamide, etc.  
         [0060]    The strips  28  to be used with the curtain holding apparatus  22  of the present invention include a series of holes  52  near the upper margin  54  of each strip as disclosed generally in FIG. 3. The size of the holes  52  is approximately the same as the size of the stalks  48  on which the strips will be suspended. The size of the holes  52  is smaller than the largest dimension of the cap  50 , which includes a distal surface  56  that is shaped to facilitate the stretching the material forming the strip  28  in the vicinity of the holes  52  to a size sufficient to permit the strip  28  to be forced over the outermost edge  58  of the caps  50  and onto the stalks  48  where the hole  52  elastically returns to its original size. By contrast, the proximal surface  60  of each of the caps  50  has a more abrupt character that can be essentially perpendicular to the stalk  48 , or convex or concave or tapered so that the abrupt change in cross-section inhibits the removal of the strip curtain  26  from the pegs  46  under the conditions of normal use, but still permit forced removal in the event it becomes necessary to replace one or more of the strips  28 .  
         [0061]    From the foregoing discussion of the various illustrated embodiments of the present invention, it will be appreciated that the various aspects and characteristics of illustrated pegs can be combined with more than one of the illustrated support bars to form a variety of resulting structures all of which follow the spirit of the present invention as previously described, and as hereafter claimed.

Summary:
An environmental strip curtain holding apparatus for suspending a plurality of flexible transparent strips forming a curtain includes a bar suitable for mounting to fixed structure adjacent to a location requiring the presence of a strip curtain. A plurality of pegs are coupled to the bar, each peg including a stalk extending outwardly from the bar. A cap is fixed to a distal end of the stalk spaced by a pre-selected distance from the bar. Each cap is generally symmetric with respect to the stalk to which the cap is fixed and has an outermost edge that is ovate to circular. The outermost edge of the cap is sized greater than the stalk to which the cap is fixed and greater than supporting holes in the strips forming the strip curtain. The distal outer surface of the cap diminishes in size from the outermost edge of the cap toward a distal extremity of the cap in such a way as to facilitate the elastic stretching of the holes in each strip to a size sufficient to permit the strip to be forced over the outermost edge of the cap.