Patent Publication Number: US-6698364-B2

Title: Folding work station

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to work stations, and more particularly to a folding work station, such as a sampling station, utilizing a ventilated wire shelving system. When folded, the folding work station presents a compact structure having a substantially flat vertical orientation and rolling support(s) to facilitate remote storage. 
     BACKGROUND OF THE INVENTION 
     Work stations commonly are used in supermarkets and other specialty stores for providing a temporary sampling station to sample various articles or food items, such as hors d&#39;oeuvres and desserts. Typically, such sampling stations include a work surface for presenting the sample articles or food items. Various display materials, such as advertising, recipes or ingredients, typically may be displayed nearby. Since the distribution of such samples is not a continuous process, such sampling stations often are disassembled for remote storage between uses. 
     Work stations which may be disassembled for storage are known. For example, wire shelving systems have found wide use in commercial and residential applications. A typical adjustable wire shelving system of the knockdown type generally comprises a plurality of support posts, usually four, provided for supporting a shelf at the four respective corners thereof. Each post includes spaced, horizontal grooves for receiving a tapered sleeve. Each shelf is formed to have frustro-conically shaped openings, or collars, at each corner. The sleeves are positioned on the posts and then received within the collars to support the shelf. 
     Conventional ventilated wire shelving generally includes a plurality of longitudinally extending wire members and a plurality of transversely extending wire members welded to one another at their respective intersecting points to form a sturdy, often rigid, wire grid structure. For additional support, a vertically oriented edge beam may be provided around the perimeter of the shelf by a serpentine-like member and a lower support member cooperating with a peripheral top wire. 
     Shelving systems as described above can be found in U.S. Pat. No. 3,523,508 and No. 3,757,705. These shelving systems are sold and marketed under the trademark SUPER ERECTA SHELF by InterMetro Industries Corporation of Wilkes-Barre, Pa. 
     Shelving systems having ventilated wire shelves are readily adaptable for storing and supporting a wide array of items, such as food items, boxes, tools, etc. Such shelving systems have particular utility in the food industry, because they provide a sturdy, lightweight, sanitary, and easily maintained environment for storing and presenting food items. 
     Knockdown type wire shelving systems as described above have great utility in many applications. However, a need exists for a work station that provides the advantages of a shelving system and that is easily and quickly set up or remotely stored on an as needed basis. In particular, a need exists for a mobile work station, such as a food sampling station, that is sturdy and yet is quickly and easily transportable and adapted for compact storage. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a folding work station, such as a sampling station, that may be easily and quickly set up or compactly stored away on an as needed basis. 
     Another object of the present invention is to provide such a folding work/sampling station that is mobile when folded to facilitate remote storage. 
     In one aspect, the present invention relates to a folding work station including a work surface and a frame supporting the work surface, where the frame includes at least one rolling support. The frame is selectively expandable to support the work surface in a first state, in which the frame is in an open configuration, the work surface is exposed in a working orientation, and the work station is stationary, and foldable to a second state, in which the frame lays flat in a closed configuration having a vertical orientation, the work surface is supported juxtaposed on the frame, and the work station is movably supported by the rolling support(s) of the frame. 
     In another aspect, the foldable work station of the present invention supports the work surface at fixed support locations at opposing ends of the work surface. In a preferred embodiment, the folding work station includes respective pivot connections between the foldable frame and the work surface at the fixed support locations. 
     In another aspect, the foldable work station of the present invention includes a first support frame, a second support frame, and foldable frame. The foldable frame connects the first support frame, the second support frame, and the work surface for relative movement between the first state, in which the second support frame is fixed relative to the first support frame at a location spaced apart from the first support frame, with the work surface supported between the first support frame and the second support frame, and the second state, in which the second support frame, the foldable frame, and the work surface are supported juxtaposed on the first support frame. 
     In another aspect, the foldable frame includes a locking brace for locking the work station in the first state. In a preferred embodiment, in the first state the locking brace cooperates with the first support frame, the second support frame and the work surface so as to fix the second support frame at a location spaced apart from the first support frame, with the work surface supported between the first support frame and the second support frame; in the second state, the locking brace folds up and also is supported juxtaposed on the first frame. In a preferred embodiment, the locking brace is an elbow brace including an upper arm, a lower arm, and a lockable hinge between the first arm and the second arm, where one arm of the locking brace is pivotably supported at a common pivot connection between the work surface and one of the first support frame and the second support frame, and the other arm of the locking brace is pivotably supported at a pivot connection on the other one of the first support frame and the second support frame. 
     In another aspect, each rolling support of the first support frame includes at least one caster, roller, wheel, or the like. For safety and ease of handling, the first support frame preferably includes at least one rolling support arranged to provide linear movement only, along a direction of a line in a plane of the first support frame. Also, each rolling support optionally may be selectively locked to prevent undesired movement, e.g., when the folding work station is expanded to the open configuration for use, or when the folding work station is folded for storage. 
     In another aspect, the folding work station of the present invention may include an optional base shelf. In a preferred embodiment, the optional base shelf is supported by the first support frame and the second support frame at fixed support locations at opposing ends of the base shelf, where the foldable frame includes respective pivot connections between the first and second support frames and the base shelf at the fixed support locations. The base shelf preferably is a ventilated wire shelf having a width substantially similar to the work surface, and is spaced apart from the work surface so as to form a parallelogram with the work surface, the first support frame and the second support frame, when viewed from a side of the work station. 
     In another aspect, the folding work station of the present invention may include an optional intermediate shelf. As with the optional base shelf, in a preferred embodiment the intermediate shelf is supported by the first support frame and the second support frame at fixed support locations at opposing ends of the intermediate shelf, and the foldable frame includes respective pivot connections between the first and second support frames and the intermediate shelf at the fixed support locations. The intermediate shelf preferably is a ventilated wire shelf having a width substantially similar to the work surface, and is spaced apart from the work surface so as to form a parallelogram with the work surface, the first support frame and the second support frame, when viewed from a side of the work station. In a preferred embodiment, one end of a locking brace is pivotably connected at a common pivot connection of the work surface and one of the first and second support frames, and the other end of the locking brace is pivotably connected at a common pivot connection of the intermediate shelf and the other one of the first and second support frames. 
     In another aspect, the folding frame includes optional securing structure, such as a resilient C-clip, for securing the first support frame together with the second support frame when the folding work station is folded in the closed configuration, and the second support frame is supported juxtaposed on the first support frame. 
     In another aspect, the folding work station of the present invention utilizes ventilated wire shelving construction. In a preferred embodiment, the folding work station includes a base shelf and/or an intermediate shelf, each formed of ventilated wire shelving. 
     These and other objects, aspects and features of the present invention readily will become apparent from the following detailed description of the preferred embodiments of the present invention, read in conjunction with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevational view of a folding work station according to a first embodiment of the present invention, illustrating the folding work station in a first state, in which the work station is locked in an open configuration, and the work station is provided with an optional base shelf. 
     FIG. 2 is a side elevational view of the folding work station illustrated in FIG.  1 . 
     FIG. 3 is a side perspective view of the folding work station of FIGS. 1 and 2, illustrating the folding work station in a second state (closed configuration), in which the work station is folded for storage. 
     FIG. 4 is a partial cross-sectional view of a pivot connection, taken along lines  4 — 4  of FIG. 2, pivotably connecting the front end of the work surface and the front support frame. 
     FIG. 5 is a partial cross-sectional view of a common pivot connection, taken along lines  5 — 5  of FIG. 2, pivotably connecting the rear end of the work surface, the rear support frame, and the locking brace. 
     FIG. 6 is a partial cross-sectional view of a pivot connection, taken along lines  6 — 6  of FIG. 1, pivotably connecting the locking brace and the front support frame. 
     FIG. 7 is a partial cross-sectional view of a pivot connection, taken along lines  7 — 7  of FIG. 1, pivotably connecting a base shelf and the front support frame. 
     FIG. 8 is an enlarged view of a stabilizing brace connection taken from dot-dashed-line  8  in FIG.  2 . 
     FIG. 9 is a partial cross-sectional view of a C-clip connector taken along lines  9 — 9  of FIG.  2 . 
     FIG. 10 is a front elevational view of a folding work station according to a second embodiment of the present invention, illustrating the folding work station in a first state, in which the work station is locked in an open configuration, and where the work station is provided with an optional base shelf and an optional intermediate shelf. 
     FIG. 11 is a side elevational view of the folding work station illustrated in FIG.  10 . 
     FIG. 12 is a partial cross-sectional view of a common pivot connection taken along lines  12 — 12  of FIG. 10, pivotably connecting a front end of the intermediate shelf, the front support frame, and the locking brace. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     FIGS. 1 and 2 are a front view and a side view, respectively, of a folding work station according to a first embodiment of the present invention, illustrating the folding work station in a first state (open, locked configuration). FIG. 3 is a side perspective view illustrating the folding work station of FIGS. 1 and 2 in a second state (closed configuration), in which the work station is folded for storage. In the present embodiment, the folding work station is a sampling station for use, e.g., in a supermarket, restaurant or commercial department store. 
     The folding work station generally includes a work surface  10  and a foldable frame  20 . In the present embodiment, the foldable frame  20  generally includes a first support frame  22 , a second support frame  24 , and at least one locking brace  26 . In the present embodiment, the folding work station also includes an optional base shelf  28 . 
     In this regard, designations “R” and “L” are used herein to refer to right and left, as viewed from the front in FIG. 1, and are arbitrarily assigned for convenience of description. For ease of production, the elements used on both the right and left sides of the work station are preferably the same elements but simply reversed when constructing the work station. Accordingly, a description herein of one element, with or without reference to the “R” or “L” designation, likewise provides a description of the “opposite side” element having the same reference number. 
     The work surface  10  generally is a rigid structure. In the sampling station of the present embodiment, the work surface  10  preferably is a rectangular tray having a solid top surface for supporting and presenting sample food items, as is well known in the art. 
     The first support frame  22  is provided at the rear or back of the folding work station, and generally includes a pair of vertical supports  30 R,  30 L, lateral support bracing, and at least one rolling support  36 . In the present embodiment, the pair of vertical supports  30 R,  30 L are spaced apart at a width “W”, the lateral support bracing includes a crown brace  32  and a cross brace  34 , and the first support frame  22  includes a pair of rolling supports  36 R,  36 L. 
     The second support frame  24  is provided at the front of the folding work station, and generally includes a pair of vertical supports  40 R,  40 L, and lateral support bracing. In the present embodiment, the pair of vertical supports  40 R,  40 L are spaced apart at a width “w”, and the lateral support bracing includes a stabilizing brace  42 . As discussed below, the spacing of the vertical supports  40 R,  40 L preferably is set so that the width of vertical supports  30  is substantially equal to the width of vertical supports  40  (W≅w), so that vertical supports  30  and  40  lay juxtaposed when the folding work stations is in the folded, closed configuration. (See, FIG.  3 ). The second support frame  24  also is shown having optional resilient C-clips  44 R,  44 L, providing means for securing the first support frame  22  and the second support frame  24  together when the folding work station is in the folded, closed configuration. 
     In the present embodiment, the first and second support frames  22 ,  24  pivotably support the work surface  10  at fixed support locations at opposing ends of the work surface  10 . More specifically, pivot connections  50 R,  50 L are provided at opposing sides of one end of work surface  10  (the front end), whereby the second support frame  22  pivotably supports the front end of work surface  10  on a common pivot axis extending between vertical supports  40 R,  40 L; likewise, pivot connections  52 R,  52 L are provided at opposing sides of the other/opposing end of work surface  10  (the rear end), whereby the first support frame  22  pivotably supports the rear end of work surface  10  on a common pivot axis extending between vertical supports  30 R,  30 L. 
     Optional base shelf  28  generally has the same width as the work surface  10  but a reduced depth, and likewise provides a rigid structure extending between, and pivotably supported by each of, the first support frame  22  and the second support frame  24 . More specifically, pivot connections  54 R,  54 L are provided at opposing sides of one end of the base shelf  28  (the front end), whereby the second support frame  24  pivotably supports the front end of base shelf  28  on a common pivot axis extending between vertical supports  40 R,  40 L; likewise, pivot connections  56 R,  56 L are provided at opposing sides of the other/opposing end of the base shelf  28  (the rear end), whereby the first support frame  22  pivotably supports the rear end of base shelf  28  on a common pivot axis extending between vertical supports  30 R,  30 L. 
     Referring particularly to FIG. 2, in the present embodiment the respective points of connection of each of the work surface  10  and the base shelf  28  to the first and second support frames  30 ,  40  (that is, the respective pivot connections) are arranged with a selected spacing, such that, when the work station is in the open configuration, the first support frame  22 , the second support frame  24 , the work surface  10  and the base shelf  28  form the four sides of a parallelogram, when viewed from the side of the work station. 
     As shown in FIG. 2, in the present embodiment the foldable frame  20  thus may be expanded to a first state, or open configuration, in which the first support frame  22 , the second support frame  24 , the work surface  10  and the base shelf  26  are pivotably moved relative to one another so as to form the four sides of a right parallelogram. In this state, each locking brace  26 R,  26 L may be locked so as to fix the first support frame  22 , the second support frame  24 , the work surface  10  and the base shelf  28  in a sturdy right parallelogram configuration. 
     Alternatively, as shown in FIG. 3, the locking braces  26  may be released, and the second support frame  24  may be lifted and translates relative to the first support frame  22  while remaining in a substantially parallel relationship therewith. As the second support frame translates, the work surface  10  and the base shelf  28  rotatably pivot relative to the first and second support frames. In this manner, the frame of the work station may be folded to a second state, or closed configuration, in which the first support frame  22 , the second support frame  24 , the work surface  10  and the base shelf  28  lay flat relative to one another, juxtaposed in a vertical orientation. 
     The materials and construction of each of the various individual elements constituting the first embodiment of the present invention are, per se, conventional. 
     The tray of work surface  10  preferably is made from a formed/pressed metal sheet, such as a stainless steel or aluminum sheet. The tray may be formed with an “optional recessed central portion,” to provide a storage compartment, and to provide additional rigidity and stability, as is well known in the art. Those skilled in the art readily will be able to select alternative materials and configurations suitable for any intended purpose. 
     Each vertical support  30 R,  30 L,  40 R,  40 L generally is a light weight, rigid, support post. In the preferred embodiment, each vertical support  30 R,  30 L,  40 R,  40 L is a metal tube, preferably a hollow stainless steel, aluminum or chrome plated steel tube. Open ends at the top and bottom of each vertical support  30 R,  30 L,  40 R,  40 L preferably are capped or otherwise treated for safety and ease of handling, as is conventionally known in the art. The height of the front vertical supports generally is selected in accordance with the desired height of the work surface. The height of the rear vertical supports  40 R,  40 L generally is selected in accordance with the desired height of the work station, e.g., for facilitating handling during transport of the work station in the folded, closed configuration, and/or for providing a physical structure for presenting a display or advertising above the work surface  10 . 
     In the preferred embodiment, each locking brace  26  is an elbow brace including an upper arm  26   a , a lower arm  26   b , and a locking hinge  26   c  pivotably connecting the upper arm  26   a  and the lower arm  26   b , where the locking hinge  26   c  selectively may be locked with the upper arm  26   a  and the lower arm  26   b  arranged in a substantially straight line. In the closed configuration, the locking braces  26  are folded and supported juxtaposed on the first support frame  22 . For example, as shown in FIG. 3, upper arm  26 La and lower arm  26 Lb are rotatably pivoted around locking hinge  26 Lc, so as to lay flat juxtaposed on one another. The elbow arms preferably are made of metal, such as chrome plated steel, or another sturdy material suitable for a food environment. Those skilled in the art readily will appreciate alternative bracing, such as telescoping bracing, or other means for selectively, locking the frame in the open configuration, and releasing the frame for folding into the closed configuration. 
     FIG. 4 is a partial cross-sectional view of a typical pivot connection of the preferred embodiment, taken along lines  4 — 4  of FIG. 2, illustrating a pivot connection  50  pivotably connecting the front end of the work surface  10  and the second (front) support frame  24 . As shown therein, a threaded bolt  60  (shown partially in phantom) sequentially is inserted through a pair of radially opposed holes (not shown) formed in the vertical support  40 R, a spacer  62  having a recessed surface (not shown) for receiving the vertical support  40 R, and a side wall (or flange)  10   a  of work surface  10 . The threaded bolt  60  then is secured in place with a washer  64  and a threaded nut  66 , so as to permit relative pivotal movement between vertical support  40 R and work surface  10 . The recessed surface of the spacer  62  preferably is crescent or semi-cylindrically shaped to compliment the shape of the vertical support  40 R (see discussion below regarding spacers provided in other pivot connections). Those skilled in the art readily will appreciate alternative structures and methods for pivotably connecting the work surface  10  and the vertical support  40 . 
     FIG. 5 is a partial cross-sectional view of a typical common pivot connection of the present invention, taken along lines  5 — 5  of FIG. 2, illustrating a common pivot connection  52 R pivotably connecting the rear end of the work surface  10 , the first (rear) support frame  22 , and the locking brace  26 . As shown therein, a threaded bolt  70  (shown partially in phantom) sequentially is inserted through a hole (not shown) in the upper arm  26 Ra of elbow brace  26 R, a washer  72 , a pair of radially opposed holes (not shown) formed in vertical support  30 R, a spacer  74  having a recessed (crescent shaped) surface  74   a  for receiving vertical support  30 R, and a hole (not shown) in the side wall  10   a  of work surface  10 . The threaded bolt  70  then is secured in place with a washer  76  and a threaded nut  78  (each shown in phantom), so as to permit relative pivotal movement among locking brace  26 R, vertical support  30 R and work surface  10 . 
     FIG. 6, is a partial cross-sectional view of a typical pivot connection, taken along lines  6 — 6  of FIG. 1, illustrating a pivot connection  58 R pivotably connecting locking brace  26 R and second (front) support frame  24 . As shown therein, a threaded bolt  80  sequentially is inserted through a hole (not shown) in the lower arm  26 Rb of locking brace  26 R, a washer  82 , and a pair of radially opposed holes (not shown) in vertical support  40 R. The threaded bolt  80  then is secured in place with a washer  84  and a threaded nut  86 , so as to provide relative pivotal movement between the locking brace  26 R and the vertical support  40 R. 
     Optional base shelf  26  preferably is a ventilated wire shelf, which provides a rigid, yet light weight structure. However, those skilled in the art readily will be able to select alternative materials and construction for base shelf  28  suitable for the intended application. As discussed below, the configuration of the preferred embodiment, including at least one optional shelf, e.g., a base shelf and/or an intermediate shelf, significantly improves the rigidity and stability of the work station. 
     FIG. 7, is a partial cross-sectional view of a typical pivot connection, taken along lines  7 — 7  of FIG. 1, illustrating a pivot connection  54 R pivotably connecting the optional base shelf  28  and the second (front) support frame  24 . As shown therein, a threaded bolt  90  sequentially is inserted through a pair of radially opposed holes (not shown) formed in vertical support  40 R, a spacer  92  having a recessed (crescent shaped) surface  92   a  for receiving the vertical support  40 R, and a hole (not shown) in a side wall portion/flange  28   a  of the base shelf  28 . The threaded bolt  90  then is secured in place with a washer  94  and a threaded nut  96 , so as to provide relative pivotal movement between base shelf  26  and vertical support  30 R. 
     As noted above, each support frame  30 ,  40  generally includes lateral support bracing. In the preferred embodiment, the lateral support bracing is provided by wire bracing, preferably using heavy gage wire conventionally used in ventilated wire shelving applications. 
     Referring again to FIGS. 1 and 2, the crown brace  32  is connected at opposing ends thereof to vertical supports  30 R,  30 L, and maintains the vertical supports at a predetermined spacing consistent with a width of work surface  10 . In the preferred embodiment, the crown brace  32  is a ventilated wire structure including an upper wire  32   a , a lower wire  32   b , and a serpentine wire  32   c  connecting the upper and lower wires, as is well known in the art. 
     The crown brace  32  may be connected to the vertical supports  30 R, 30 L by any conventional means. In the preferred embodiment, crown brace  32  is connected to vertical supports  30 R,  30 L by providing opposing ends of the upper wire  32   a  with extended portions which are inserted through respective pairs of radially opposed holes (not shown) formed in the upper ends of vertical supports  30 R,  30 L. The extended end portions preferably are secured in place with respective caps  33 R,  33 L. Caps  33  may be fixed to the extended end portions of upper and lower wires  32   a  by any conventional means, such as press fitting, welding, adhering, threading, etc. Of course, those skilled in the art readily will appreciate alternative structures and methods for securing the ends of cross brace  34  to the vertical supports  30 R,  30 L. (see also the discussion of stabilizing brace  42  below for details of connection design). The opposing ends of the lower wire  32   b  preferably are inserted through respective holes (not shown) formed only on interior facing sides of the vertical supports  30 R,  30 L (see FIG.  1 ). It will be appreciated that this construction prevents any rotation of the crown brace  32  about upper wire  32   a , stabilizes the upper portion of the first support frame  20 , and facilitates easy assembly thereof. However, those skilled in the art readily will appreciate alternative methods and structures for connecting opposing ends of the crown brace  32  to the vertical supports  30 R,  30 L. 
     The cross brace  34  generally comprises two wires arranged in an x-shape, with respective ends of each wire being connected to the vertical supports  30 R,  30 L. Similar to the connection of the crown brace  32  discussed above, each end of the cross brace wires may be bent and inserted through respective pairs of radially opposed holes (not shown) formed in the vertical supports  30 R,  30 L, and secured in place using conventional caps  35  (see FIG.  2 ). The caps  35  may be fixed to the extended end portions of the upper and lower wires  32   a , by any conventional means, such as press fitting, welding, adhering, threading, etc. Of course, those skilled in the art readily will appreciate alternative structures and methods for securing the ends of cross brace  34  to the vertical supports  30 R,  30 L. 
     Although the preferred embodiment employs a cross brace  34  together with a crown brace  32  to provide lateral support for maintaining the first support frame  20  in a rigid configuration, those skilled in the art readily will appreciate alternative bracing structures and configurations for maintaining the first support frame  20  in a rigid configuration. 
     In the preferred embodiment, the stabilizing brace  42  has a design similar to the crown brace  32 , and is comprised of an upper wire  42   a , a lower wire  42   b , and a serpentine wire  42   c  disposed therebetween. However, in the stabilizing brace  42 , the serpentine wire  42   c  only is provided in a central section of stabilizing brace  42 , and the upper and lower wires diverge from one another at each of the opposing ends of stabilizing brace  42 . This arrangement provides both aesthetic and structural functions. However, those skilled in the art readily will appreciate alternative arrangements suitable for any desired application. 
     FIG. 8 illustrates a typical connection between a heavy gage wire brace and a vertical support. Specifically, each of the respective ends of upper wire  42   a  and lower wire  42   b  has a bent portion  42   aa ,  42   bb  that is inserted through a respective pair of radially opposed holes (not shown) formed in respective vertical supports  40 R,  40 L, and is secured in place using a press fit cap  43 . Caps  43  may be fixed to the extended end portions of the upper and lower wires  42   aa ,  42   bb  by any conventional means, such as press fit, welding, threading, adhering, etc. Of course, those skilled in the art readily will appreciate alternative structures and methods for connecting each brace wire to a vertical support  40 R,  40 L. 
     The crown brace  32 , the cross brace  34  and the stabilizing brace  42  are designed and configured to individually provide a desired amount of lateral and shear stability and rigidity to the respective first and second frames  22 ,  24  and, in combination with the foldable frame, the work surface  10  and any optional shelves, to collectively provide a desired lateral stability and rigidity to the folding work station. Of course, the illustrated number, structure and arrangement of these elements merely are provided as examples of stabilizing structures. Those skilled in the art readily will appreciate alternative structures and arrangements for providing appropriate lateral stability and rigidity for a particular application. 
     As discussed above, in the preferred embodiment predetermined spacings (W, w) respectively are provided between the vertical support posts  30 R,  30 L and  40 R,  40 L, and the spacings preferably are substantially equal (W≅w). In this manner, when the work station is folded to the second state (closed configuration), the second support frame  24  lays juxtaposed on the first support frame  22 , and may be secured to the first support frame. In the preferred embodiment, the second support frame  24  is snap-locked onto the first support frame  22  by a pair of C-clips  44 R,  44 L, thereby to securely maintain the work station in the closed, folded configuration (see FIG.  3 ). 
     FIG. 9 is a partial cross-sectional view of a C-clip connector taken along lines  9 — 9  of FIG.  2 . As shown therein, a threaded bolt  100  sequentially is inserted through a resilient C-clip  44 R, a spacer  102  having a recessed (crescent shaped) surface  102   a  for receiving vertical support  40 R, and a pair of radially opposed holes (not shown) formed in the vertical support  40 R. The threaded bolt  100  then is secured in place with a threaded nut  104 . 
     In the embodiment of FIGS. 1 and 2, when locking braces  26  lock the work station in the first state (open configuration), the work surface  10  and the base shelf  28  are directly supported by the vertical supports  30 R,  30 L,  40 R,  40 L of the first and second support frames  22 ,  24 , and the locking braces  28 R,  28 L cooperate with the work surface  10  and the shelf frame  26  to maintain the first and second support frames  22 ,  24 , in a fixed spaced relation. It will be appreciated that in this manner the work station of the present embodiment provides a stable platform for presenting sample items, such as food samples or other articles in a restaurant, supermarket or department store; it also provides a stable shelf, e.g., for storing additional stock. 
     It also will be appreciated that, when the work station of the first embodiment is folded to the second state (closed configuration), the second frame  24 , the work surface  10  and the base shelf  28  are supported juxtaposed on the first frame  22 , and the work station readily and easily may be stored flat, e.g., laying down or standing substantially upright against a wall. 
     Also, when the work station is folded to the second state (closed configuration), the work station readily is transportable on rolling supports  36 R,  36 L, such as wheels, casters, rollers or like. In this regard, although the preferred embodiment of FIGS. 1 to  3  includes two rolling supports, it readily will be appreciated that the work station only requires one moving support structure to provide mobility. 
     In the preferred embodiment, at least one of the rolling supports  36 R,  36 L is arranged to provide rolling movement in a single direction only, that is, along a line in the plane of the first support frame  22 . It will be appreciated that such an arrangement improves the stability of the work station while being transported and stored folded up in the second state (closed configuration), thereby facilitating safe, easy handling. Providing only two such movable supports, on the rear vertical supports  30 R,  30 L, also substantially eliminates undesired movement of the work station when sitting in the first state (open configuration). 
     Second Embodiment 
     FIG. 10 is a front view and FIG. 11 is a side view of a folding work station according to a second embodiment of the present invention. In this embodiment, the work station is provided with an optional base shelf and an optional intermediate shelf. Features of the second embodiment which are the same as the first embodiment are identified with the same reference numbers. Accordingly, description of these features is not repeated herein. 
     Optional intermediate shelf  110  generally has the same width as the work surface  10  but a reduced depth, and likewise provides a rigid structure extending between, and pivotably supported by each of, the first support frame  22  and the second support frame  24 . More specifically, common pivot connections  112 R,  112 L are provided at opposing sides of one end of intermediate shelf  110  (the front end), whereby the second support frame  24  pivotably supports the front end of intermediate shelf  110  on a common pivot axis extending between vertical supports  40 R,  40 L; likewise, pivot connections  114 R,  114 L are provided at opposing sides of the other/opposing end of the intermediate shelf  110  (the rear end), whereby the first support frame  22  pivotably supports the rear end of intermediate shelf  110  on a common pivot axis extending between vertical supports  30 R,  30 L. 
     Referring particularly to FIG. 11, in the present embodiment the respective points of connection of each of the work surface  10  and the intermediate shelf  110  to the first and second support frames  30 ,  40  (that is, the respective pivot connections) are arranged with a selected spacing, such that, when the work station is in the open configuration, the first support frame  22 , the second support frame  24 , the work surface  10  and the intermediate shelf  110  form the four sides of a parallelogram, when viewed from the side of the work station. 
     As shown in FIG. 11, in the present embodiment the foldable frame  20  may be expanded to a first state, or open configuration, in which the first support frame  22 , the second support frame  24 , the work surface  10 , and the intermediate shelf  110  are pivotably moved to form the four sides of a right parallelogram. In this state, each locking brace  26 R,  26 L may be locked so to fix the first support frame  22 , the second support frame  24 , the work surface  10  and the intermediate shelf  110  in a right parallelogram configuration. 
     Alternatively, similar to the first embodiment illustrated in FIG. 3, the locking braces  26 R,  26 L may be released, and the second support frame  24  may be lifted and rotatably pivoted, with the work surface  10 , the intermediate shelf  110 , and the base shelf  28 , relative to the first support frame  22 , so as to fold the frame to a second state, or closed configuration, in which the first support frame  22 , the second support frame  24 , the work surface  10 , the intermediate shelf  110 , and the base shelf  28  lay substantially flat relative to one another, juxtaposed in a vertical orientation. 
     As in the first embodiment, each of the various elements of the second embodiment may be made using conventional materials and construction. 
     Optional intermediate shelf  110  preferably is a ventilated wire shelf, which provides a rigid, yet light weight structure. However, those skilled in the art readily will be able to select alternative materials and constructions for the intermediate shelf  110  suitable for the intended application. As previously discussed, the configuration of the preferred embodiment, including at least one shelf, e.g., a base shelf and/or an intermediate shelf, significantly improves the rigidity and stability of the work station. However, the present embodiment, including an intermediate shelf  110  having a common pivot connection with locking brace  26 , further improves the stability of the folding work station. 
     FIG. 12 is a partial cross-sectional view of a common pivot connection taken along lines  12 — 12  of FIG. 10, pivotably connecting a front end of the intermediate shelf frame  110 , the front support frame  24 , and the locking brace  26 . In the preferred embodiment, common pivot connection  112 R comprises a threaded bolt  120  sequentially inserted through a hole (not shown) in the lower arm  26 Rb of locking brace  26 R, a washer  122 , a pair of radially opposed holes (not shown) formed in the vertical support  40 R, a spacer  124  having a recessed (crescent shaped) surface  124   a  for receiving the vertical support  40 R, and a hole (not shown) in a side wall or flange  110   a  of the intermediate shelf  110 . The threaded bolt  120  then is secured in place with a washer  126  and a threaded nut  128 , so as to permit relative pivotal movement among the intermediate shelf  110 , the vertical support  40 R and the locking brace  26 R. 
     While the present invention has been described with respect to what is presently considered to be the preferred embodiments, the present invention is not limited to the disclosed embodiments. Rather, the present invention covers various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.