Abstract:
A photography lightbank is extendable axially and radially to a larger size by an extension ring, which is removably attachable to the distal (front) end of the lightbank shroud. Extension rod connectors are configured for attachment of extension rods, which support the extension ring in outstretched configuration, to the distal ends of the primary support rods that support the lightbank shroud, while releasable fasteners attach the proximal end of the extension ring to the distal end of the shroud.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention is related to lightbanks for illuminating photographic objects, and more specifically to a removable extension that enlarges the lightbank. 
   2. State of the Prior Art 
   Lightbanks are used by photographers to create whatever lighting environment they need to illuminate photographic objects for the effects they want their photographs to portray. Conventional lightbanks, usually comprise a light source, a shroud to confine and direct the light produced by the light source, a diffuser panel to scatter and distribute the light evenly to reduce glare spots and dark spots, and a support structure. They are available in various sizes ranging from less than a foot to twenty feet or more across. Most professional photographers find that they need at least several different sizes and that they would like to have more. However, lightbanks are fairly expensive, and they are bulky and not easy to carry and set up, especially the medium and larger sizes. Consequently, many photographers are discouraged about purchasing and having all the lightbank size and shape variety they want or need at their photographic studios. Also, even if they have a variety of sizes and shapes available, some photographers are still discouraged about transporting more than one or two of them to off-site locations. 
   SUMMARY OF THE INVENTION 
   An object of the invention, therefore, is to provide a more versatile lightbank that can be converted from one size to another. 
   Another object of the invention is to provide several lightbank sizes with only moderate additional cost and bulk. 
   To achieve the foregoing and other objects of the invention, a shroud extension is detachably connectable to the distal end of a lightbank shroud to effectively enlarge the shroud axially and/or radially. The extension can include a fabric ring with a plurality of extension or extendable support rods, which are sized and shaped to match and attach to and/or extend from the distal end of the lightbank shroud. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the preferred embodiments of the present invention, and together with the written description and claims, serve to explain the principles of the invention. In the drawings: 
       FIG. 1  is a side elevation view of a shroud extension attached to, and protruding axially and radially from the distal end of the primary shroud of a lightbank assembly to enlarge the lightbank according to this invention; 
       FIG. 2  is a front end elevation view of the shroud extension of  FIG. 1 ; 
       FIG. 3  is an enlarged cross-sectional view of the extension shroud attached to the distal (front) end of the primary shroud taken substantially along section line  3 — 3  of  FIG. 2 ; 
       FIG. 4  is a perspective view of the shroud extension mounted on the primary shroud of a lightbank assembly according to this invention; 
       FIG. 5  is a perspective view similar to  FIG. 4 , but with the extension diffuser panel partially detached to reveal portions of the interior of the shroud extension and of the primary diffuser panel attached in its proper place in the primary shroud; 
       FIG. 6  is a perspective view similar to  FIGS. 4 and 5 , but with the extension shroud completely removed and the primary diffuser panel partially detached from the primary shroud; 
       FIG. 7  is a perspective view similar to  FIGS. 4–6 , but with the extension shroud detached from the primary shroud; 
       FIG. 8  is an enlarged view of an example terminal abutment of the distal end of an extension rod in the extension fabric ring at the location indicated in  FIG. 4 ; 
       FIG. 9  is an enlarged view of an extension rod and immediately surrounding portions of the fabric extension ring attached to adjacent portions of the primary shroud and primary shroud support rod in the location indicated in  FIG. 6 ; 
       FIG. 10  is a view similar to  FIG. 9 , but with the extension rod and extension fabric ring detached from the primary shroud and primary shroud support rod; 
       FIG. 11  is an enlarged view of an example terminal abutment of a distal end of a primary shroud support rod in the distal end of the primary shroud that also accommodates detachable connection of the extension rod to the primary shroud support rod; 
       FIG. 12  is an illustration similar to  FIG. 11 , but of another example connection of the extension rod connection to the primary shroud support rod; 
       FIG. 13  is another example variation of a connection of the extension rod to the primary shroud support rod; 
       FIG. 14  is an illustration of another example abutment that can be used at the distal end of the primary shroud support rod, which can be opened as shown in phantom lines to accommodate connection of the extension rod to the primary support rod; and 
       FIG. 15  is an illustration, partly in cross-section, of an example telescoping primary shroud support rod with an extension rod, which is slideable telescopically into and out of the primary shroud support rod. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A shroud extension  100  is shown in  FIGS. 1 and 4  mounted on the distal (front) end  22  of the primary shroud  20  of a conventional lightbank assembly  10  to enlarge the lightbank assembly  10  axially and radially according to this invention. As best seen in  FIGS. 1 ,  3 , and  7 , a typical conventional lightbank assembly  10  comprises an extendable and collapsible shroud  20 , which is often made of opaque fabric, plastic, or other opaque material that does not allow light to escape, and which is supported in its outstretched, use configuration by a plurality of resilient support rods  12  anchored in some kind of frame  14 . For special applications or special lighting effects, the shroud  20  fabric or other material could be translucent to allow some light to escape, but usually the shroud  20  is opaque. 
   The frame  14  of a conventional lightbank  10  is often either part of, or mounted around, a housing  16 , which contains a light source  18 . The housing  16  can be supported in myriad ways, but it is often supported by a tripod stand  19 . The support rods  12  keep the fabric shroud  20  outstretched to extend axially and radially from the frame to confine light produced by the light source and direct it forwardly in a generally axial direction to a space, object, or background, which a photographer wants to illuminate. The number of support rods  12  is optional, but, usually, a larger shroud  20  requires either a larger number of support rods  12 , or the support rods  12  should be stronger, or both. A larger number of rods  12  will provide a different polygonal shape for the distal (front) end  22  of the shroud  20 . In the example illustrated in  FIGS. 1–7 , eight support rods  12  are used, which provides an octagonal shape. Four support rods  12  would provide a square shape, for example, and six support rods  12  would provide a hexagonal shape. 
   A flexible diffuser panel  30  (best seen in  FIG. 7 ), which is usually made of a white, translucent material that scatters light, has a peripheral edge  32  that is sized and shaped to conform to the size and shape of the primary shroud  20  adjacent its distal (front) border  22 . Therefore, it is attached around its peripheral edge  32  to the inside surface  24  of the primary shroud  20  to extend substantially perpendicular to the longitudinal axis  50  of the lightbank  10  across the front of the primary shroud  20  adjacent the distal border  22  of the primary shroud  20 . The diffuser panel  30  can be attached around its peripheral edge  32  to the primary shroud  20  in any convenient manner. The diffuser panel  30  in the example illustrated in  FIG. 7  is attached by mating hook and loop fastener strips  34 ,  36 , such as Velcro™ hook and loop fastener strips, although snaps, zippers, tie cords, buttons, rivets, thread, tape, or any of a number of other fastener instrumentalities could also be used. As is also shown in  FIG. 7 , an optional additional diffuser panel  38  is also sometimes used inside the primary shroud  20  to ensure an even more uniform scattering and distribution of light without glare, brighter, or darker zones. 
   The primary shroud support rods  12  typically extend through sleeves  40  sewn into the fabric of the primary shroud  20 , as perhaps best seen in  FIG. 3 , although the support rods  12  could be retained in position by looped straps (not shown) or other means. In smaller lightbanks, it may not be necessary to use any retainers for the support rods  12 . It is usually desirable, though, to provide some form of abutment structure  42  ( FIG. 7 ) at the distal end  22  of the shroud  20  for abutment by the distal ends  46  of the support rods  12 , so that, when the proximal ends  48  of the support rods  12  are mounted to the frame  14 , the support rods  12  are placed in compression to bend or deform in a resilient manner to the outstretched shape or configuration of the shroud  20  in a manner similar to an unfolded, extended umbrella. In some lightbanks  10 , the support rods  12  are straight and deformed by compression into the outstretched shape of the shroud  20 , and, in others, the support rods  12  are pre-formed or bent into the desired shape. 
   As shown in  FIGS. 1–7 , the typical shape of the outstretched primary shroud  20  extends from its proximal end  21  adjacent the housing  16  in a somewhat parabolic shape to its distal end or border  22  to form a longitudinal axis  50 . For purposes of this description, the longitudinal axis  50  extends generally through the center of the light source  18  ( FIG. 3 ) and through the center point of the polygonal figure formed by the distal end  22  of the outstretched fabric shroud  20 . Therefore, the shroud  20  is described as extending generally axially and radially outward from the housing  16 , which means in the direction of the longitudinal axis  50  as well as in radially away from the longitudinal axis  50 , as shown in  FIGS. 1–7 . The front end of the lightbank  10  is synonymous with the area circumscribed by the distal border  22  around the longitudinal axis  50 , so the back end is generally the housing  16  and frame  14  end of the lightbank  10 . 
   The shroud extension  100 , shown in  FIGS. 1–7 , comprises an extension ring  120  of flexible fabric or other material with a proximal end border  121  that, when outstretched, is sized and shaped to match and attached to the distal border  22  of the primary shroud  20 . From its proximal border  121 , the ring  120  flares axially and radially outward in relation to the longitudinal axis  50  to an extension distal border  122 , which is larger than the primary distal border  22 . Therefore, when the shroud extension  100  is attached to the primary shroud  20 , as shown in  FIGS. 1–7 , the effective size of the lightbank  10  is enlarged both axially and radially to create a different lighting effect than the lightbank  10  with the primary shroud  20  alone. The extension ring  120  is preferably made with an opaque fabric or other material similar to the primary shroud  20 , but, for special lighting requirements, it can be made with a translucent material, as explained above for the primary shroud  20 . 
   The structure of the shroud extension  100  can also be similar in many respects to the structure of the primary shroud  20 . For example, the plurality of extension rods  112  (shown in phantom lines in  FIG. 3  and the proximal ends  144  of which are shown in  FIG. 7 ) can be slideably positioned into sleeves  140  formed and sewn into the extension ring  120  and abutted against distal end abutment structures  142 , as shown in  FIGS. 1–8 . Connection of the proximal ends  144  of the extension rods  112  to the distal ends  46  of the primary support rods  12  will be described in more detail below. An extension diffuser panel  130  can be provided in the front end of the shroud extension  100 , if desired. However, the primary diffuser panel  30  is attached to the primary shroud  20  in a manner that does not interfere with attachment of the shroud extension  100  to the distal end border  22  of the primary shroud  20 , so the primary diffuser panel  30  can remain in place to scatter, soften, and evenly distribute light when the shroud extension  100  is attached in place for use. Consequently, use of either the extension diffuser panel  130  and/or the primary diffuser panel  20  is optional, as is use of the additional diffuser panel  38  in the primary shroud  20 . However, for most photographic lighting applications, the extension diffuser panel will probably be used whenever the shroud extension  100  is used. 
   The extension diffuser panel  130  has a peripheral edge  132  that preferably matches in size and shape to the inside surface  124  of the extension ring  120  adjacent the distal end border  122  of the extension ring  120 . Therefore, the extension diffuser panel  130  can be attached to the inside surface  124  of the extension ring  120  by any convenient detachable fastener or attachment instrumentality, such as the hook and loop fastener strips (Velcro)  134 ,  136  around the inside surface  124  adjacent the distal edge border  122  and around the peripheral edge  132 , respectively, as best seen in  FIG. 5 . Of course, as mentioned above, other attachment instrumentalities, such as snaps, buttons, cords, threads, rivets, zippers, glue, tape, and others, could be used in place of, or in addition to, the hook and loop fastener strips  134 ,  136 . Also, the fasteners can be inverted so that the extension ring  120  attaches to the external surface of the primary shroud  20 , if desired. In any event, it is preferred that there be an overlap of the distal end border  22  over the proximal end border  121  or vice versa to help prevent light leakage through the seam where the extension ring  120  attaches to the primary shroud  20 . 
   As mentioned above, the proximal ends  144  of the extension rods  112  can be detachably connected to the distal ends  46  of the primary support rods  12  in any convenient manner that will enable the extension rods  112  to support the extension ring  120  in its outstretched, use configuration, which configuration is shown in  FIGS. 1–6 . Therefore, it is preferred, although not essential, that the rod connection structure be one that enables the extension rods  112  to be put under some compression between the primary rods  12  and the abutment structures  142 , if desired, to make the extension rods  112  conform to and support the full outstretched shape of the extension ring  120 . 
   An example detachable extension rod connector  60  that can provide this kind of function, as well as the function of keeping the primary support rods  12  in compression, as described above, is illustrated in  FIGS. 9–11 . Essentially, the connector  60  in this example includes a ferrule portion  61  with an axial hole  62  in one end, which is fitted onto the distal end  46  of the primary support rod  12 . As also illustrated in  FIGS. 10 and 11 , the rod connector  60  has a stub shaft portion  64  extending axially away from the distal end  46  of the primary support rod  12 . The stub shaft portion  64  of the connector  60  is smaller in diameter than the ferrule portion  61 , so there is an annular shoulder  66  on the connector  60 . The abutment structure  42  of the primary shroud  20  includes a grommet  70  with a hole  72  diameter that is large enough to fit over the stub shaft portion  64  of the connector  60 , but which is too small to fit over the ferrule portion  61 . Therefore, the shoulder  66  of the connector abuts the grommet  70  of the abutment structure  42  ( FIGS. 10 and 11 ) to limit axial movement of the primary support rod  12  in relation to the primary shroud  20 , thereby enabling the primary support rod  12  to be maintained in compression when the proximal end  44  of the primary support rod  12  is anchored to the frame  14  ( FIG. 3 ). 
   Then, as illustrated in  FIGS. 9–11 , the proximal end  144  of the extension rod  112  can have a hole  148  with an inside diameter that is large enough to receive and slide over the stub shaft portion  64  of the connector  60  to connect the extension rod  112  to the primary support rod  12 . The proximal end  144  of the extension rod  112  can then abut the grommet  70  to limit axial movement of the extension rod  112  in relation to the primary support rod  12  and thereby, if desired, maintain the extension rod  112  under some compression between the grommet  70  ( FIGS. 9–11 ) and the abutment structure  142  ( FIG. 8 ) on the shroud extension  100 . If a grommet  70  is not used, the proximal end  144  of the extension rod  112  can abut directly on the annular shoulder  66  of the connector  60  for much the same effect. 
   Of course, the connector  60  could also be structured inversely, for example, the connector  60  shown in  FIG. 12  has two oppositely directed stub shafts  64 ,  64 ′ for sliding into hollow ends  46 ,  144 , respectively of the rods  12 ,  112 . A shoulder  66  between the two stub shafts  64 ,  64 ′ can abut the grommet  70  for the same effect as that described above for the connector  60 . As another alternative, either the distal end  46  of the primary support rod  12  or the proximal end  144  of the extension support rod  112  can be machined or otherwise made with a smaller diameter stub shaft  64 ″, as illustrated in  FIG. 14 , while the opposite proximal end  142  or distal end  46  is hollow with a hole  62 ′ large enough to receive the stub shaft  64 ″. The grommet  70 , if there is one, can abut either the shoulder  66 ′ created by the smaller diameter portion  64 ″ of the rod  12  or  112 , or the shoulder  66 ″ created by the wall thickness of the rod  112  or  12  around the hole  62 ′. In another example connector  60 , illustrated in  FIG. 13 , the connector  60  comprises a dowel pin  68  extending into, and axially away from, the hollow distal end  144  of the primary support rod  12 . The portion  64 ′ of the dowel pin  68  that extends into the distal end  46  of the primary support rod  12  can be held in place by any common technique, such as glue, friction, crimping, etc., which are well within the knowledge and capabilities of persons skilled in the art. The external portion  64  is sized to fit through the hole  72  in grommet  70  and into the hole  148  in the proximal end  144  of the extension rod  112  to connect the extension rod  112  to the primary support rod  12  in the same manner as described above. In this example, the grommet  70  abuts the distal end  46  of the primary support rod  12 . Persons skilled in the art will be able to devise many other connector structures for the rods  12 ,  112  to provide some or all of the functions described above to implement and practice this invention, once they understand the principles of this invention. 
   The abutment structure  42  of the primary shroud  20  can include the grommet  70  affixed to a piece of reinforcing fabric  74  or other material sewn, glued, or otherwise attached to the shroud  20  fabric or other material, for example, as illustrated in  FIGS. 10–13 . Alternatively, as illustrated in  FIG. 14 , the abutment structure  42  can include a flexible strap or flap  76  sewn or otherwise attached to one part of the reinforcing fabric  74  and detachably connected to another part of the reinforcing fabric  74  by a fastener, for example, the hook and loop type fastener strip  78 ,  79 . When the extension rod  112  is not attached to the primary support rod  12 , the flap  76  can be closed and fastened to the reinforcing fabric  74  by the fasteners  78 ,  79 , so the distal end  46  of primary support rod  12  abuts the flap  76 . Then, in order to connect the extension rod  112  to the primary support rod  12 , the flap  76  can be detached from the reinforcing fabric  74  and moved aside, as illustrated by the phantom lines  76 ′. The extension rod  112  can then be moved into place for connection to the primary support rod  12  in any manner, as described above. 
   Instead of separate extension rods  112 , as shown and described in the examples above, the extension rods  112  can be telescoped into and out of the primary support rod  12 , an example of which is illustrated in  FIG. 15 . In this example, the extension rod  112  slides, as indicated by arrow  86  into the primary support rod  12  for storage, when the extension shroud  100  ( FIGS. 1–7 ) is not attached to the primary shroud  20 . However, for support of the fabric ring  120 , when the extension shroud  100  is attached to the primary shroud  20 , the extension rods  112  can be pulled telescopically out of the primary support rods  12  and extended through the sleeves  140  of the extension shroud  100  and into the extension rod abutment  142 , as illustrated in  FIG. 15 . The extension rod  112  can be retained in this extended position by any suitable latch or other device, many of which are well-known, for example, the spring-biased button latch  90  shown in  FIG. 15 . In this example, the button latch  90  comprises a push button  91  mounted in the extension rod  112  near its proximal end  144 . The push button  91  is biased by spring  93  to protrude radially from the extension rod  112 . Normally, when the extension rod  112  is retracted into rod  12 , the sidewall of rod  12  prevents such radial protrusion. However, when the extension rod  112  is extended to a point where the push button aligns with a side hole  92  in the primary rod  12 , the spring  93  causes the push button  91  to protrude radially through the hole  92 , where it prevents any further relative sliding movement between the extension rod  112  and the primary support rod  12 . Of course, to retract the extension rod  112 , the push button  91  can be pushed manually against the bias of spring  93  back inside rod  12  to again permit slideable movement of the extension rod  112  in relation to primary support rod  12 . The knob  94  at the distal end  146  of the extension rod  112  can be used to prevent the extension rod  112  from being retracted too far inside the primary support rod  12 . The grommet  70  of the primary abutment structure  42  abuts the distal end  46  of the primary support rod  12  in the same manner as described above. The extension abutment structure  142  can be a piece of reinforcing fabric  174  fastened to the extension ring  120  to form a pocket to receive and retain the distal end  146  of the extension rod  112  in the same manner as shown in  FIGS. 1–7  or any other suitable manner to support the distal (front) end  122  of the extension ring  120  against the extension rod  112 . 
   The proximal end border  121  of the extension ring  120  is preferably detachably connected to the distal end border  22  of the primary shroud  20 , both to add structural support for the shroud extension  100  and to prevent leakage of light through the seams where the primary shroud  20  meets the extension ring  120 . While there are many attachment instrumentalities, such as snaps, buttons, zippers, cords, and others that can be used for these purposes, hook and loop type fastener strips  82 ,  84 , such as Velcro™, are preferred and shown in  FIGS. 7 and 9  as well as indicated in  FIGS. 3 ,  5 , and  6  in which one or both of the hook and loop strips  82 ,  84  are hidden by an overlaying flap or border piece. Therefore, with reference primarily to  FIGS. 7 and 9 , and secondary reference to  FIGS. 3 ,  5 , and  6 , strips  82  of one type (hook or loop) of the fastener material are positioned preferably, but not essentially, on the inside surface  24  of the primary shroud  20  adjacent the distal end border  22 . Strips  84  of the other, mating type (hook or loop) of the fastener material are positioned preferably, but not essentially, on the outside surface  126  of the extension ring  120  adjacent the extension proximal border  121 . Therefore, when the mating fastener strips  82 ,  84  are fastened together, outside surface  126  of the extension ring  120  adjacent the extension proximal border  121  is detachably connected substantially around its periphery to the inside surface  24  of the primary shroud  20  adjacent the primary distal border  22 . Again, the fastener strip  82  is between the primary distal border  22  and the fastener strip  34  for the primary diffuser panel  30 , so attachment of the primary diffuser panel  30  to the primary shroud  20  does not interfere with attachment of the extension ring  120  to the primary shroud  20  and vice versa. 
   The foregoing description is considered as illustrative of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and process shown and described above. Accordingly, resort may be made to all suitable modifications and equivalents that fall within the scope of the invention. The words “comprise,” “comprises,” “comprising,” “include,” “including,” and “includes” when used in this specification are intended to specify the presence of stated features, integers, components, or steps, but they do not preclude the presence or addition of one or more other features, integers, components, steps, or groups thereof.