Abstract:
The present invention is directed to a collapsible food guard for displaying and serving food comprising a resilient transparent cover assembly for a substantially planar base. The cover assembly is substantially semi-cylindrical of a predetermined radius and has closed opposing ends. The cover assembly is reversibly pivotably attached to a base and has downward facing edges to seal the cover to the base when the cover is pivoted in the down (closed) position. The semi-cylindrical portion of the cover assembly is a resilient transparent shield that reversibly detachable from the arched surfaces of the closed opposing ends (side walls) and is sufficiently resilient such that when detached form the arched surfaces of the opposing side walls, it assumes the substantially planar shape in which it was initially molded. This resiliency allows the collapsible food guard to collapse into planar elements (side walls, shield and optional base) requiring minimal storage space and providing easy cleaning.

Description:
FIELD OF THE INVENTION 
     The present invention is in the field of food service and display. More particularly, the present invention is a device for displaying foods under a clear protective canopy that allows for easy viewing, protection against insects and wind burn and provides for easy cleaning. Because the device of the present invention is collapsible to a flattened or substantially planar form, it is storable in a minimal space. The present invention is useful because it provides a reusable, readily storable, and readily cleanable device for protecting foods from environmental factors and preserving freshness in an outdoor or indoor setting. 
     BACKGROUND OF THE INVENTION 
     Serving food outdoors is a great American tradition. However, containers of open food are often an invitation to annoying insects which light upon the food and render it unappetizing to unsanitary. Also, the wind can dry out many foods, particularly breads and cakes, rendering them hard or unappetizing. At picnics, tables are decked with covered food containers which are suddenly uncovered to allow guests access to the food within a short window. Typically, the covers are solid (e.g., foil) or opaque plastic or heavy glass. The former two do not allow sight of the food until removed. The latter cover, while allowing sight of the food, is heavy, often the size of the serving container, and must be moved to a location other than the serving table for lack of room to set it down while accessing the food. Otherwise, one needs a cooperative guest to hold the cover while one accesses the food underneath. When the covers are removed, it is often a battle between the guests and the insects as to who gets the food. This causes the foods to be recovered and one has to peak under the many covers to rediscover that dish from which one seeks seconds. At large commercially catered events, the problem becomes even more exaggerated. It is an object of the present invention to provide a device that displays food under a clear sanitary cover, that allows one to single handedly tilt the cover to gain access to the food, and to retilt the cover down to reprotect the food while offering visual access and decision making to the next guest. In this way, all the guests do not have to eat as soon as the food is opened and can access food and desserts at their palates desire. 
     A second problem at such gatherings is cleaning and storing all of the food containers. Food covers for plates and desserts add another dimension to the storage needs of the homeowner. On a commercial scale, the storage needs for such covers, which largely occupy open space, becomes immense. Accordingly, it is another object of the present invention to provide a food guard that is readily collapsible to a substantially planar (space saving) shape during non-use. This planar shape also facilitates cleaning, particularly in a mechanical washer. A further object is that the space saving (substantially planar) shape must readily reassemble into its curved (space encompassing) shape when needed for duty. A further object is that assembly must be simple and not require tools to affect completion. 
     U.S. Pat. No. 5,542,560, entitled “Protective and Warming Bonnet for Food,” issued to Gerster, et al., on Aug. 6, 1996. The &#39;560 patent teaches a collapsible food cover that is a “folding bellows . . . made of pleated paper, in the manner of a Chinese lanterns.” U.S. Pat. No. 4,422,441, entitled “Disposable Stackable Splatter shield and Frame Thereof,” issued to Schoeppe on Dec. 27, 1983, discloses a collapsible splatter shield that is a pleated metal foil. However, neither of these devices has any permanency, neither is cleanable, and neither allows one to visualize what is underneath when in an operative position. 
     Des. Pat. 259,690, entitled “Dish with Hinged Cover,” issued to Buchsteiner nee Fetzer on Jun. 30, 1981. The &#39;690 patent discloses a non-collapsible fixed shape dish with a transparent hinged cover. While the &#39;690 patent allows one to see the food under the cover, the device is an assembled unit that is not collapsible and thus occupies substantial space when stored en mass. Thus, there is an unsolved need for a space saving device that allows one to visualize and access food on a congested table, and that after use is readily collapsible to facilitate storage in a minimal amount of space. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a collapsible food cover, display and server (hereinafter “collapsible food guard”) having multiple embodiments. In one embodiment, the present invention is directed to a collapsible food guard for displaying and serving food comprising a resilient transparent cover assembly for covering a substantially planar base. The cover assembly is substantially semi-cylindrical in shape, having a predetermined radius and having closed opposing ends (side walls). The cover assembly is reversibly pivotably attached to the base by way of a hinge member. The cover assembly also has downward facing edges to seal the cover to the base when the cover is pivoted in the down (closed) position. When the cover assembly is pivoted in the upward (open) position, the cover assembly exposes the base and any contents thereon. The cover assembly has a hinge member for slideably engaging and disengaging from the planar base, such as after use. The semi-cylindrical portion of the cover assembly is a resilient transparent shield that reversibly detachable from the arched surface of the closed opposing ends and is sufficiently resilient such that when detached form the arched surfaces of the opposing ends, it assumes the substantially planar shape in which it was initially molded. This resiliency allows the food cover to collapse into planar elements (side walls, resilient shield and optional base) requiring minimal storage space. 
     It is within the scope of the above described embodiment that the collapsible food guard have a resilient transparent cover that is a clear resilient plastic such as but not limited to polycarbonate, polyethylene terephthalate or polyvinyl chloride, more preferably, a polycarbonate. It is also within the scope of the above described embodiment that the substantially planar base is wood, plastic (e.g., melamine), glass, ceramic, stone, or a stone composite. Such bases are discussed in more detail herein. A preferred base is wood, plastic, or ceramic, preferably a wooden cutting board, a service tray, a service platter or a perimeter frame for the base. The perimeter frame (which looks like a wooden picture frame) acts as a base and support for the shield assembly and allows the user to place her favorite platter under the shield assembly. It is also within the scope of this embodiment that the cover is reversibly pivotably attached to the base by a male hinge member that slideably inserts into a hinge slot on the upper planar surface of the base, such as shown in  FIG. 1  or  FIG. 3 . Preferably, the hinge slot has a circular cross-section comprising from 182° of arc to 350° of arc, more preferably, from 188° of arc to about 245° of arc. It is also within the scope of the present invention that the hinge be a live hinge. When the hinge is a live hinge, the hinge slot may have any cross sectional shape because the correspondingly shaped male hinge member does not need to rotate in the hinge slot. However, the live hinge may also be used in combination with a hinge slot that has a substantially circular cross-section 
     In another embodiment, the present invention is directed to a collapsible food guard for displaying and serving food comprising a stationary base member and a pivotable shield assembly; the stationary base member comprising a substantially planar upper surface having a linear hinge slot therein sized and shaped for slideably receiving a male hinge member, the pivotable shield assembly being semi-cylindrical in shape and having opposing closed ends, the pivotal shield assembly comprising a resilient transparent shield, a first opposing sidewall and a second opposing sidewall, the resilient transparent shield being substantially rectangular in shape having a frontal edge, a distal edge and two opposing lateral edges, the distal edge being attached to a male hinge member that is sized and shaped for slideably entering the linear hinge slot on the stationary base member to form a pivotable hinge, each of the opposing sidewalls having an arcuate upper surface for reversibly engaging a respective opposing lateral edge of the resilient transparent shield and having a planar lower surface for pivotably engaging the planar surface of the base member, the opposing lateral edges of the resilient transparent shield having substantially the same length as the arcuate upper surface such that when the resilient transparent shield is bent to engage and conform to the arcuate surface, the opposing side walls and shield forming a pivotable semi-cylindrical dome having planar base, the planar base forming a seal with the planar upper surface of the stationary base member when the pivotable shield assembly pivots downward, thereby displaying any item thereunder, the shield assembly providing access to any contents under the shield assembly when the shield assembly pivots upward. 
     In yet another embodiment, a resilient transparent shield assembly comprising a resilient transparent shield and opposing side walls having slideable hinge assemblies  70  and  80  is a stand alone invention in itself. This latter invention is usable with the consumer&#39;s existing base member, albeit a cutting board, a tray or a platter, and does not require a proprietary base member as part of the invention. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of the collapsible food guard of the present invention in the assembled and closed (display) position having an optional notch  4  and latch  9  combination for retaining the resilient transparent shield  5  in the closed position. 
         FIG. 2  is a perspective view of the collapsible food guard of  FIG. 1  in the open (serving) position allowing access to any food (not shown) contained therein.  FIG. 2  also displays one type of hinge that is suitable for opening and closing the resilient transparent shield  5 . 
         FIG. 3  is a close up view of the hinge region of the open collapsible food guard of  FIG. 2 . 
         FIG. 4  is a close up view of the mortise and tenon type joinery that is used for reversibly attaching the lateral edges of the resilient transparent shield along the arched surfaces of the respective opposing walls. 
         FIG. 5  is a solitary view of base member  1  as shown in each of  FIGS. 1-3  with optional notch  4  and arcuate hinge slot  3 . 
         FIG. 6  is a view of the disassembled upper element of the collapsible food guard of  FIGS. 1-4  in a collapsed substantially planar form, ready for assembly or storage. 
         FIG. 7  is an exploded view of yet another embodiment of the collapsible food guard of the present invention. 
         FIG. 8  is an close-up view of one opposing hinge  40  suitable for use in pivotably opening and closing the shield assembly of  FIG. 7  relative to its substantially planar base member  45 . 
         FIG. 9  is a view of the collapsible food guard of  FIG. 7  in the disassembled and collapsed mode with the resilient transparent shield  38  assuming its substantially planar and relaxed position. In the collapsed mode, both the base  45  and the shield assembly  62  are substantially planar and storable in a minimum of space. 
         FIG. 10  is a view of an optional restraint for restraining the resilient transparent shield in a tensioned and arched position against the arched surface of an opposing sidewall. 
         FIG. 11  is a view of another optional restraint device for restraining the resilient transparent shield in a tensioned and arched position against the arched surface of an opposing sidewall. 
         FIG. 12  is a view of yet another optional restraint device for restraining the resilient transparent shield in a tensioned and arched position against the arched surface of an opposing sidewall. 
         FIG. 13  is a view of the semi-assembled embodiment of  FIG. 10  wherein the resilient transparent shield  38  is in its natural flat position before being flexed to an arched position so as to engage the arched surfaces of the opposing side walls and their respective twistable shield mount latches  55  to form a collapsible food guard in the closed position such as shown in  FIG. 15 . 
         FIG. 14  is a view of the collapsible food guard of  FIG. 7  in the fully open position. 
         FIG. 15  is a view of the collapsible food guard of  FIG. 7  in the closed position. 
         FIG. 16  is a view of the collapsible food guard of  FIG. 7  with the hinge of  FIG. 8  in the partially open position. 
         FIG. 17  is an exploded view of an opposing pair of alternative hinges for slideably and reversibly attaching the pivotable shield assembly to the stationary base member. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The collapsible food guard of the present invention has multiple embodiments.  FIG. 1  discloses a collapsible food guard  10  of the present invention in the assembled and closed (display) position and comprises a stationary base member  1 , and a pivotable shield assembly thereover comprising a resilient transparent shield  5  and two opposing walls  8 A and  8 B. The base member is has a substantially planar upper surface  2  and is made from any material suitable for presenting, serving, cutting or storing food. Suitable materials for the base member  1  are materials that are machinable or moldable to a flat surface, and include wood (e.g., plank, or a laminate cutting board), plastics (e.g., melamine), stone (e.g., marble, granite, onyx), glass, a composite (e.g., CORIAN®), a ceramic or laminates (e.g., FORMICA®). (e.g., a cutting board), glass, plastic, or stone (such as granite or marble). When plastic is used, the plastic is food grade, nonporous for easy cleaning and may be transparent, translucent or opaque and optionally colored. It is also within the scope of the present invention that the base member be in the form of a tray or platter. The resilient transparent shield  5  is typically made from a substantially rectangular sheet of clear resilient plastic that can be bent repeatedly to form a gently curved surface (see  5  in  FIG. 1 ) by applying minimal hand pressure and that will return to a flat surface (see  5  in  FIG. 6 ) when the applied pressure is removed. The resilient transparent film must be thick enough to be resilient when bent as in  FIG. 1  yet not so thick as to crack upon repeated bending. Preferred plastics for the resilient transparent shield  5  are polycarbonate, polyvinyl chloride (PVC) or polyethylene terephthalate (PET). All these plastics are commercially available. A more preferred plastic is polycarbonate. Suitable polycarbonates are sold under the trademarks LEXAN® or LUCITE®. Suitable thicknesses for the resilient transparent shield range from 0.0156 to 0.0626 inches. The collapsible food guard  10  has two opposing side walls  8 A and  8 B that have matching arched (arcuate) surfaces  18 A and  18 B, respectively. In  FIG. 1 , the resilient transparent shield  5  is bent to engage arched surfaces  18 A and  18 B and conform to their length and curvature. To retain the resilient transparent shield  5  in its curved conformation, the opposing lateral edges  14 A and  14 B of resilient transparent shield  5  each have 1-4 mortises (slots)  6  for receiving corresponding tenons  7  projecting from each of arched surfaces  18 A and  18 B of corresponding side walls  8 A and  8 B, respectively. Preferably, there are 2-3 mortise and tenon joints along each arched surface. More preferably, there are 3 mortise and tenon joints along each arched surface  18 A and  18 B, such as the three shown in  FIG. 1 . Because the lateral edges  14 A and  14 B of the resilient transparent shield are substantially the same length as the length of arched surfaces  18 A and  18 B, when the resilient transparent shield is fixed to the arched surfaces  18 A and  18 B, the bottom of sidewalls  8 A and  8 B, the frontal edge  12  of shield  5  and the distal edge  11  of shield  5  form a plane that is suited for seating upon the planar upper surface  2  of the stationary base member  1 . The opposing side walls  8 A and  8 B of food guard  10  are made of any material described herein, including wood, stone, glass or plastic. In one embodiment, the opposing side walls  8 A and  8 B are made of the same material as the stationary base member  1 . In another more preferred embodiment, the opposing side walls  8 A and  8 B are made of the same material as the resilient transparent shield  5 . Thus, depending upon their construction material, the opposing side walls are transparent, translucent or opaque. Optionally, the opposing side walls  8 A and  8 B are vented by incorporating an opposing screen (not shown) on or into each of the side walls. The opposing screens allow condensation to dissipate when hot food is stored under the shield assembly and prevent the resilient transparent shield  5  from losing its transparency due to condensation building up on the shield&#39;s  5  inside surface. The opposing side walls are support walls and thus are generally thicker than the resilient transparent shield. The side walls have a thickness that ranges from ⅛ inch to ¾ inches depending upon the material selected. When the walls are thin, they are optionally flared along their peripheral edges to a “T” shape to give the walls greater strength against bending and a wider arched surface for supporting and engaging the resilient transparent shield. 
     In  FIG. 1 , the base member  1  has a substantially planar upper surface  2  for engaging the plane formed by the bottom edges of the pivotable shield assembly (combined resilient transparent shield  5  and opposing side walls  8 A and  8 B) when the latter is in the closed (food display) position as shown in  FIG. 1 . This coplanar arrangement creates an effective seal between the shield assembly and the base member  1  for keeping bugs and the outside environment away from the food stored therein. In the embodiment of  FIG. 1 , the closed shield assembly does not extend over any of the edges of the stationary base member as shown in  FIG. 1 . To obtain the maximum protected area for any size of stationary base member, it is also within the scope of this invention that frontal edge  12  and/or side walls  8 A and  8 B extend just beyond the upper surface  2  of stationary base member  1  (not shown). The upper surface  2  of base member  1  has a hinge slot  3  running substantially parallel along the base member&#39;s  1  posterior edge, the slot  3  being sized and shaped for slideably engaging major hinge  13  member (not shown) that allows the pivotable shield assembly ( 5 + 8 A+ 8 B) to pivot as a unit as shown in  FIG. 2 . Optionally, the base member  1  has a notch  4  adjacent its frontal edge for engaging an optional peg or latch  9  when the pivotable shield assembly ( 5 + 8 A+ 8 B) is in the closed position as shown in  FIG. 1 . 
       FIG. 2  is a perspective view of the collapsible food guard  10  of  FIG. 1  in the open (serving) position  20 , allowing access to any food (not shown) contained therein. When the collapsible food guard is in the open position  20 , frontal edge  12  of resilient transparent shield  5  will exhibit a natural bow, as shown, due to the resilient nature of the shield  5 . Optionally, the frontal edge  12  of the resilient transparent shield incorporates a peg or latch  9  that will engage the stationary base member  1  to affect a reversible closure of the pivotal shield assembly. In the embodiment of  FIG. 2 , stationary base member  1  preferably has notch  4  for receiving optional latch (or peg)  9  when the pivotable shield assembly ( 5 + 8 A+ 8 B) of the collapsible food guard  20  is returned from the open position as shown in  FIG. 2  to the closed position as shown in  FIG. 1 . The optional latch  9  may be shaped and sized to frictionally engage notch  4  along one or more of its sides. Latch (or peg)  9  may also be tapered at its attack end (the end distal to frontal edge  12 ) to facilitate entry into notch  4  before frictional engagement occurs higher up the shaft. However, to take advantage of the natural outward bowing of frontal edge  12 , latch  9  preferably has a lateral rib (or protrusion) that engages a lateral groove (or dimple) on the internal front face of notch  4 . This optional combination secures the pivotable shield assembly in the closed position. The latch  9  is unsecured simply by exerting thumb pressure above latch  9  to displace it backward, thereby countering the outward bow and disengaging the rib (or protrusion) from the lateral groove (or dimple) inside notch  4 . Optionally, a thumb-sized area on the surface of the resilient transparent shield along its frontal edge  12  immediately above latch  9  is frosted or contains ribbing or indicia to indicate that it is the point for lifting. Other securing mechanisms that take advantage of the natural resilient pressure on the frontal edge  12  of shield  5  may also be optionally used, e.g., a ball on the end of a peg  9  that engages a dimple in notch  4 . When present, the peg or latch  9  is preferably made of the same material as the resilient transparent shield  5 . More preferably, the peg or latch  9  is coextruded with the resilient transparent shield  5  so that they are a single unitary piece. 
       FIG. 3  is a close up view of the hinge region of the open collapsible food guard  20  of  FIG. 2 . In  FIG. 3 , the hinge slot  3  on upper surface  2  of base member  1  is shown as having a preferred circular cross-section. In this embodiment, hinge slot  3  has a cross-section defined by a circular arc that is greater than 182° of arc but less than about 350° of arc, more preferably, from 188° of arc to about 245° of arc. 
     Hinge slot  3  is sized and shaped for slideably receiving a male hinge member  13 . When the male hinge member  13  has a circular in cross-section, as shown in  FIG. 3 , and when the circular hinge slot  3  encompasses about 240° of circular arc as shown, then the male hinge member  13  can rotatably pivot about the 120° of open arc above the hinge slot  3 . This embodiment produces little stress upon the male hinge member  13  or its connection along distal edge  11  to the resilient transparent shield  5 . In this embodiment, male hinge member  13  and the resilient transparent shield  5  are preferably coextruded at the same time as a single unitary piece of plastic. 
     Because the resilient transparent shield  5  is resilient, it is also within the scope of this invention that the hinge connecting the resilient transparent shield  5  to the stationary base member  1  be a live hinge. A live hinge is created by simply reducing the size of the arc that is open above hinge slot  3  such that the male hinge member  13  is unable to rotate in hinge slot  3  and all pivoting of the shield assembly is by flexion of the resilient transparent shield  5  adjacent the male hinge member  13 . When the hinge is a live hinge and the male hinge member is not required to rotate (or pivot) in the hinge slot  3 , both the male hinge member  13  and the corresponding female hinge slot  3  may take on any shape, e.g., triangular, square, rectangular, inverted-T shape, without affecting the functionality of the collapsible food guard  10  of the invention. The male hinge member  13  is affixed to the distal edge  11  of the flexible transparent shield  5  by any technique that is well known in the art (e.g., gluing, ultra-sonic welding, riveting). Alternatively, the live hinge can be a separate element composed of a flexible polymer, having along its length a male hinge member  13  sized and shaped for sliding into the female hinge slot  3  and having along its opposing length a member for engaging the distal edge  11  of at the resilient transparent shield  5 , such as by a slot, a glued seam, an ultrasonic weld, or a mechanical fastener, such as a plurality of rivets. However, the preferred method for connecting the male hinge member  13  (regardless of its shape) to the distal edge  11  of the resilient transparent shield  5  is by coextrusion of both as a single unitary piece. 
       FIG. 4  is a close-up view of the details of two types of mortise and tenon joints for reversibly retaining the lateral edges of the resilient transparent shield  5  in an arched position against the arched surfaces ( 18 A and  18 B) of side walls  8 A and  8 B, respectively. Because of the inherent resiliency in the arched sheet of plastic that comprises the resilient transparent shield  5 , the arched shield  5  has a tendency to try to straighten out and pop off the tenons  7  protruding from the arched surface  8 A (and  8 B not shown). To overcome this tendency, the tenons are provided with a protrusion  17 , such as a tapered nub or rib, along their lateral surface  16  that resists the mortise (slot)  6  in the resilient transparent shield from moving off the tenon without the further application of an external force greater than that exerted by the resiliency of the arched resilient transparent shield  5 . Each of the nubs or ribs would extend outward from the width of the tenon by 0.4-8%, typically by 0.5-4%, more typically, by 0.5-3%. Alternatively, the lower edge of tenon  7  has a tenon notch  19  that retains the resilient transparent shield in the arched position. This notch exploits the natural tendency of the resilient transparent shield  5 , when arched, to pull up and forward (i.e., to try to straighten), thereby engaging the notch. The holding effect of the notch  19  is released simply by pulling the shield  5  first downward to disengage the notches, and then forward to disengage the mortises (slots)  6  from their corresponding tenons  7 . 
       FIG. 5  is a solitary view of stationary base member  1  as shown in each of  FIGS. 1-3  with optional notch  4  and arcuate hinge slot  3 . Optional notch  4  may be any shape suited to accommodate receipt of latch or peg  9 . For ease of cleaning, notch  4  is optionally a through-hole extending through the entire thickness of stationary base member  1 . When notch  4  has a rectangular opening, as shown in  FIG. 5 , it would accommodate receipt of a correspondingly rectangular shaped latch  9  on the frontal edge  12  of transparent shield  5  when the pivotable shield assembly ( 5 + 8 A+ 8 B) is pivoted to the down position as shown in  FIG. 1 . As discussed above, the optional latch (or peg)  9  may frictionally engage one or more sides or walls of the notch  4 . In one embodiment, the attack end of the latch or peg is tapered to facilitate entry into notch  4 . Optionally, the proximal wall of the notch  4  has a lateral groove (or dimple) for receiving a correspondingly shaped and positioned rib (or nub) protruding from latch  9 . Typically, the hinge slot  3  is cut into stationary base member  1  using an appropriately shaped cutting tool such as a router blade corresponding in shape to the cross-sectional shape of the hinge slot that is desired. However, when the stationary base member  1  is plastic, the hinge slot  3  may be molded directly into the plastic. As discussed above, the stationary base member is made of any material that is suitable for contact with food. Typical suitable materials include wood (e.g., a plank or a laminated cutting board), plastics, stone (e.g., marble, granite, onyx), glass, composites (e.g., CORIAN®) or laminates (e.g., FORMICA®). 
       FIG. 6  is a view of the disassembled upper element of the collapsible food guard of  FIGS. 1-4  in a collapsed substantially planar form, ready for assembly or for storage. In  FIG. 6 , the resilient transparent shield  5  is shown in its natural flat form with optional latch  9  along frontal edge  12  and male hinge member  13  adjacent distal edge  11 . Opposing side walls  8 A and  8 B are attached to opposing lateral edges  14 A and  14 B of resilient transparent shield  5  via opposing hinges  21 A and  21 B, respectively. While any hinge would be suitable for this function; preferably, the opposing hinges  21 A and  21 B are a live hinge as shown in  FIG. 6 . In the embodiment of  FIG. 6 , the resilient transparent shield  5  and lateral side walls  8 A and  8 B are coextruded as a single piece. Preferably, the opposing live hinges  21 A and  21 B are formed upon extrusion by simply reducing the thickness of the resilient transparent shield  5  at its point of attachment to side walls  8 A and  8 B respectively (i.e., along the hinge lines  21 A and  21 B), thereby forming a relatively weaker area between shield  5  and walls  8 A and  8 B, where bending would preferentially occur upon application of pivotal pressure. More preferably, resilient transparent shield  5 , opposing side walls  8 A and  8 B, male hinge member  13 A and latch or peg  9  are all coextruded as a single substantially planar piece as shown in  FIG. 6 . The natural resiliency in the plastic would cause the combined elements to assume the relaxed (collapsed) form shown in  FIG. 6  when no mortise  6  and tenon  7  connections are made. 
     Less typically, opposing hinges  21 A and  21 B are formed after coextrusion along lateral edges  14  A and  14 B of the coextruded form ( 5 + 8 A+ 8 B) by mechanically making a first bend between side wall  8 A and shield  5  along edge  14 A to create a preferential line of weakness that becomes hinge  21 A. Likewise, a second bend is made between sidewall  8 B and shield  5  along edge  14 B to create a preferential line of weakness that becomes hinge  21 B. 
       FIG. 7  is an exploded view of another embodiment of a collapsible food guard of the present invention. In  FIG. 7 , the resilient transparent shield  38  has opposing lateral edges  34 A and  34 B that arch over and conform to the length and shape of arched surfaces  36 A and  36 B of opposing side walls  53 A and  53 B, respectively. The combination of the resilient transparent shield and the opposing side walls (the shield assembly) form a substantially semi-cylindrical canopy that substantially covers the planar upper surface  49  of a stationary base member  45 . The stationary base member is made from any of the materials described herein. It is also within the scope of the invention that the base member  45  be a cutting board or be substituted with a service tray, service platter or perimeter frame. The resilient transparent shield  38  and the opposing sidewalls are made from the materials already described herein for the other embodiments. Unlike the other embodiments described herein, the embodiment of  FIG. 7  has an optional anterior edge bar  42  and a posterior edge bar  41 . The optional edge bars  41  and  42  stiffen the respective edges of the transparent resilient shield  38  and keep the anterior edge  33  and posterior edge  32  of the shield from excessive bowing. This allows one to use a thinner resilient transparent film as shield  38 . The edge bars are made of the same or different material as the resilient transparent membrane. Preferably, the edge bars are made of the same material as the sidewalls. Suitable materials for the edge bars  41  and  42  include wood, metal or plastic. Suitable plastics include polyethylene, polypropylene, polycarbonate, polyvinyl chloride, polyethylene terephthalate, various methyacrylates and mixtures thereof. Preferably, the edge bars  41  and  42  are made of the same material as the resilient transparent shield  38 . More preferably, when the edge bars  41  and  42  are made of the same material as the resilient transparent shield  38 , the edge bars  41  and  42  and the resilient transparent shield are extruded or injection molded as a single unitary piece. Even more preferably, the resilient transparent shield  38 , the side walls  53 A and  53 B, and the edge bars  41  and  42  are coextruded as a single unitary piece. The edge bars  41  and  42  also accommodate additional types of closures, and connections. Specifically, a magnet  44  emitting a magnetic field and a magnetically attractive catch plate  43  are suitable for use in combination as a latching mechanism for the closed shield assembly. In  FIG. 7 , separate magnetically attractive catch plates  43  are attached to opposing underside ends of anterior edge bar  42 . When the resilient transparent shield is in the closed position (see  FIG. 15 ), the magnetically attractive catch plates  43  engage two magnets  44  positioned below them on the substantially planar upper surface  49  of base member  45 . The magnetic force between the magnets  44  and magnetically attractive catch plates provide a positive latching force for reversibly retaining the shield assembly in the closed position. Although  FIG. 7  displays the magnets  44  on the base member  45  and the magnetically attractive plate  43  on the edge bar  42 , it is also within the scope of the present invention that their relative positions be reversed. It is also within the scope of the present invention that the latching mechanism for the shield assembly comprises a single magnet  44  and single magnetically attractive catch plate  43  that are substantially centrally juxta-positioned along opposing faces of anterior edge bar  42  and the upper surface  49  of the base member  45 . The magnet  44  is any permanent magnet, typically an iron magnet. The magnetically attractive catch plate  43  is typically a metallic plate comprising iron or an iron alloy. However, for increased holding power, the magnetically attractive catch plate  43  is optionally another permanent magnet with its N and S poles positioned to be opposite those of magnet  44  so as to be mutually attractive. When the edge bar  42  is made of iron, a separate magnetically attractive catch plate  43  is not needed since the iron edge bar  42  itself would also function as a magnetically attractive catch plate. In an alternative embodiment (not shown), the magnetic latch(s) of  FIG. 7  are replaced with a mechanical latch such as the mortise and pin latch of  FIG. 1 . 
     In  FIG. 7 , the anterior lateral corner of the resilient transparent shield as defined by anterior edge  33  and lateral edge  34 A is affixed to its opposing sidewall  53 A by a living hinge  52 . Likewise, the anterior lateral corner of the resilient transparent shield as defined by anterior edge  33  and lateral edge  34 B is affixed to its opposing sidewall  53 B by a living hinge  52 . Preferably, these live hinge attachments are permanent such that the combination of the shield  38 , opposing sidewalls  53 A and  53 B and the pair of hinges  52  are a single unitary piece. The live hinges  52  are permanently attached to the shield  38  and the opposing side wall by gluing, ultrasonic welding, or by the initial injection molding. More preferably, the combination of the shield  38 , opposing sidewalls  53 A and  53 B and the pair of hinges  52  are formed at the same time by injection molding as a single unitary piece. Even more preferably, the combination of the shield  38 , edge bars  41  and  42 , opposing sidewalls  53 A and  53 B and the pair of live hinges  52  are formed at the same time by injection molding as a single unitary piece. Because the resilient transparent shield  38  is molded as a flat piece, it naturally assumes its substantially planar shape when not curved over the arched surfaces  36 A and  36 B of the opposing side walls  53 A and  53 B. Moreover, when not assembled, the opposing side walls  53 A and  53 B naturally fold along live hinges  52  to also form a planar shape that stacks over the planar transparent resilient shield  38 . See  FIG. 9 . This planar shape facilitates storage in a minimum of space. Alternatively, the live hinge  52  could be a conventional pinned hinge (not shown). The collapsed shield assembly is converted into the assembled shield assembly by unfolding each of the opposing side walls along hinge  52  by 90° relative to the resilient transparent shield  38  and folding the lateral edges  36 A and  36 B of the resilient transparent shield  38  along the respective arched surfaces  36 A and  36 B of opposing sidewalls  53 A and  53 B until each of the corners along the posterior edge  32  of the resilient transparent shield engage a reversible latch at the bottom posterior end of arched surfaces  36 A and  36 B respectively. In  FIG. 7 , the reversible latch is shown as an anchor pin  65  protruding out of each of opposing lateral walls  53 A and  53 B. The anchor pin is sized and shaped for reversibly engaging first pin holes  63  along opposing posterior corners of shield  38  and second pin holes  69  along posterior edge bar  41 . In one embodiment, the pins  65  frictionally engage the sides of pin holes  69  to reversibly retain the resilient transparent shield in a tensioned and arched configuration over arched surfaces  36 A and  36 B of opposing sidewalls  53 A and  53 B, respectively. Alternatively, as shown in  FIG. 7 , the anchor pins  65  extend beyond the second pin holes  69  and engage an edge clip  63  which provides the required resistance to reversibly hold shield  38  in the arched (and tensioned) position. 
     In  FIG. 7 , the assembled shield assembly is pivotably mounted to the stationary base member  45  by a pivoting mechanical hinge assembly separately attached to each of the opposing side walls  53 A and  53 B. The mechanical hinge typically has two hinge members and a hinge pin about which the hinge pivots. In the embodiment of  FIG. 7 , one of the hinge members  48  is stationary as it is bound to the stationary base member  45 , and the pivotable hinge member  47  is pivotably mounted via hinge pin  50  to the outside surface of its respective sidewall. Stationary hinge members  48  reversibly mount into opposing hinge slots  46  in base member  45 , thereby allowing the assembled and mounted shield assembly to pivotably open and close over the planar upper surface  49  of base member  45 , exposing or covering its contents, respectively. Because the first hinge member is reversibly attached to the base member  45 , the assembled shield assembly can be readily removed from the base member  45  and readily disassembled from arched to planar form as shown in  FIG. 9 . The pivotable hinge member  47  is attached to the outside face of its opposing side wall by any means known in the art, including screws, adhesive, ultrasonic welding and integral construction. Thus, it is within the scope of the present invention that the pivotable hinge member  47  and the opposing sidewall  53 A or  53 B to which it is attached be coextruded as a single unitary piece. 
       FIG. 8  is an close-up view of one opposing hinge assembly  40  suitable for use in pivotably opening and closing the shield assembly of  FIG. 7  relative to the stationary and substantially planar base member  45 . The hinge assembly comprises stationary hinge member  48  pivotably connected to pivotable hinge member  47  by hinge pin  50 . The inside faces of stationary hinge member  48  and pivotable hinge member  47  have two series of nubs or teeth  60  that in various degrees of pivot engage one another to form a position brake where the increased resistance from the interacting nubs provides reversible stops that hold the hinge in a partially open (venting) position or in a fully open position. See  FIG. 8 . The resistance created by the engaging nubs  60  is sufficient to hold the shield assembly in partially open position ( FIG. 16 ) or the fully open position ( FIG. 14 ) but is readily overcome by application of hand pressure. In  FIG. 8 , stationary hinge member  48  has a lower portion that is an anchor key  51  that is sized and shaped for securely sliding into slot  46  on the upper surface  49  of base member  45  and anchoring the stationary member  48  of the hinge assembly  40  when it is pivotably connected to the pivotable shield assembly. The depth that the anchor key  51  sinks into slot  46  is controlled preferably by a pair of protruding stop rests  58 . The stop rests allow one to see that the anchors are fully pressed into the slots and assure that both hinges are at the same depth and properly aligned. Preferably, stationary hinge member  48  has a lock and release latch  61  with lip  57  (for engaging a corresponding notch in slot  46 ) and a pressure release tab  59  (for disengaging lip  57  from the notch (not shown) in slot  46 ). In this embodiment, stationary hinge member  48  has a T-shaped footprint and slot  46  is correspondingly T-shaped as shown in  FIG. 7  to accommodate the footprint. As already discussed herein, it is also within the scope of this invention that the pivotable hinge member  47  be of unitary construction with its respective wall member; preferably, the opposing wall member ( 53 A or  53 B) and its corresponding pivotable hinge member  47  be injection molded at the same time as a single unitary piece of plastic. 
       FIG. 9  is a view of the collapsible food guard of  FIG. 7  in the disassembled and collapsed mode with the resilient transparent shield  38  assuming its substantially planar and relaxed position. In the collapsed mode, both the base  45  and the shield assembly  62  are substantially planar and storable in a minimum of space. 
       FIG. 10  is a view of an optional restraint for restraining the resilient transparent shield in a tensioned and arched position against the arched surface of an opposing sidewall. In  FIG. 10 , the restraint is a twistable shield mount latch  55 . The twistable shield mount latch has a stationary segment and a twistable (or rotatable) segment. The stationary segment is affixed near the bottom posterior end of arched surface  36 A of opposing side wall  53 A and extends outward from the arched surface  36 A a distance equal to at least the combined thickness of the shield  38  and the posterior edge bar  41 . The twistable portion begins at distance from the arched surface that is at least the combined thickness of the shield  38  and the edge bar  41  which it reversibly restrains. Although the twistable portion of latch  55  is shown in  FIG. 10  as a rectangular block, other oblong rotatable restraining devices, such as a butterfly or wing nut, may alternatively be screwed into the stationary portion of latch  55 . In use, a relevant portion of the shield  38  and the posterior edge bar  41  each have a hole or slot sized and shaped for sliding over the latch  55  when twisted in the open position. Once the shield  38  and edge bar  41  have slid over the latch and against the arched surface  36 A of the wall  53 A, the twistable oblong portion of latch  55  is rotated so that its wider dimension engages the outside surface of the posterior edge bar  41  and restrains it and the shield in the arched position as shown. Although the restraint of  FIG. 10  is shown for one opposing side wall  53 A, it is equally applicable to the other opposing side wall  53 B for restraining the opposing edge of the resilient transparent shield  38  against arched surface  36 B. It is also within the scope of the present invention that the stationary segment of the twistable shield mount latch  55  be integrally attached to its respective opposing wall; preferably, the side wall and the stationary portion of latch  55  is injection molded at the same time as a single piece of plastic. 
       FIG. 11  is a view of another optional restraint device for restraining the resilient transparent shield in a tensioned and arched position against the arched surface of an opposing sidewall. The restraint in  FIG. 11  is a detailed view of one embodiment of the restraint depicted in use in the collapsible food guard of  FIG. 7 . In  FIG. 11 , an anchor pin  65  projects out adjacent the posterior end arched surface  36 A. The length of anchor pin  65  depends upon its function. In use, transparent shield  38  and posterior edge bar  41  have first pin hole  63  and second pin hole  69 , respectively. When anchor pin  65  restrains shield  38  by passing through first pin hole  63  and frictionally engaging the sides of second pin hole  69 , then the anchor pin may but need not be longer than the combined thicknesses of the shield  38  and the posterior edge bar  41 . However, if the anchor pin  65  does not frictionally engage the inside surface of the second pin hole  69  sufficiently to restrain the shield  38  in the arched position, then the anchor pin  65  needs to have a length that is sufficiently longer than the combined thicknesses of the shield  38  and posterior edge bar  41  so as to engage a retaining clip. Typically, this additional length is within the range of ⅛ inch to ½ inch. In the embodiment of  FIGS. 7 and 11 , the anchor pin  65  sticks out sufficiently beyond the edge of posterior edge bar  41  so that a retaining clip  63  with a circular aperture  64  frictionally engages anchor pin  65 , thereby restraining shield  38  against arched surface  36 A in a reversible manner. Alternatively, anchor pin  65  is slotted for receiving a U-shaped retaining clip wherein the inside gap in the U-shaped clip is the diameter of the notch (not shown). When the shield  38  and the posterior edge bar  41  are slid over the notched anchor pin, the notch projects beyond the edge bar  41  and the U-shaped clip is slid into the notch and the shield  38  and posterior edge bar  41  are restrained against arched surface  36 A in a reversible manner. Although the restraint of  FIG. 11  is shown for one opposing side wall  53 A, it is equally applicable to the other opposing side wall  53 B for restraining the opposing edge of the resilient transparent shield  38  against arched surface  36 B. It is within the scope of the present invention that the anchor pin be integrally attached to its respective opposing wall, such as by screwing, adhesives or ultrasonic welding. Preferably, the side wall and the corresponding anchor pin  65  are injection molded at the same time as a single piece of plastic. Moreover, any parts that are described herein as being injection molded with a side wall are capable of being injection molded in combination with all other parts so described as a single unitary piece. 
       FIG. 12  is a view of yet another optional restraint device for restraining the resilient transparent shield in a tensioned and arched position against the arched surface of an opposing sidewall. In  FIG. 12 , the opposing ends of posterior edge bar  41  each have a key block  68  projecting therefrom sized and positioned for frictionally engaging a key slot  67  in the lower posterior end of arched surface  36 A of side wall  53 A. The friction in the slot should be sufficient to overcome the resilient tension in the shield  38  produced by its arching but not so high as to prevent its easy removal when storage is needed. Typically, no more than 10 lbs of force should be required. 
       FIG. 13  is a view of the semi-assembled embodiment of  FIG. 10  wherein the resilient transparent shield  38  is in its natural flat position before being flexed to an arched position so as to engage the arched surfaces  36 A and  36 B of the opposing side walls  53 A and  53 B, respectively, and their respective twistable shield mount latches  55  which engage opposing latch slots  56  to form a collapsible food guard in the closed position such as shown in  FIG. 15 . 
       FIG. 14  is a view of the collapsible food guard of  FIG. 7  in the fully open position. This figure also depicts when a second group of brake nubs or teeth  60  of the hinge assembly  40  catch or engage one another and provide sufficient resistance to hold the weight of the pivotable shield assembly in a substantially fully open position. 
       FIG. 15  is a view of the collapsible food guard of  FIG. 7  in the closed position. 
       FIG. 16  is a view of the collapsible food guard of  FIG. 7  with the hinge of  FIG. 8  in the partially open position. This figure depicts when a first group of brake nubs or teeth  60  of the hinge assembly  40  catch or engage one another and provide sufficient resistance to hold the weight of the pivotable shield assembly in the partially open position. 
     Although the opposing side walls of  FIGS. 7-16  do not show any vents, it is also within the scope of this invention that the opposing side walls optionally include opposing vents so as to minimize condensation caused by storing hot foods underneath. As discussed herein, such vents are either a series of slits in the side wall of screens. Preferably, the vents are screens. The screens are either inserted in windows after molding or are premolded into the walls. More preferably, the screens, when present, are premolded into the side walls during the injection molding process. 
       FIG. 17  is an exploded view of an opposing pair of alternative hinges for slideably and reversibly attaching the pivotable shield assembly to the stationary base member. In  FIG. 17 , right side hinge  70  and left side hinge  80  are mirror images of one another. Right side hinge  70  is an assembly comprising pivotable hinge member  71 , stationary hinge member  76  and pin  90  for pivotably interconnecting hinge members  71  and  76 . Pivotable hinge member  71  has hinge side face  74 , which faces the opposing hinge member  76 , and wall side face  72  (not shown) which is affixed to the outside face of the right opposing sidewall (not shown), such as sidewall  8 A in  FIG. 1  in lieu of live hinge  13 , or to sidewall  53 A in  FIG. 7  in lieu of pivotable hinge member  47 . Optionally, hinge side face  74  has raised ribs or teeth  75  that interact with raised (or depressed) ribs or teeth  75  on the hinge side surface (not shown) of stationary hinge member  76 . The corresponding teeth or ribs can be seen on the hinge side surface  84  of the mirror image stationary hinge member  86 . When the opposing teeth or ribs  75  engage one another, they create a temporary stopping point for the hinge assembly that is overcome by applying additional force. In one embodiment, the opposing teeth  75  are positioned to engage each other when the pivotable shield assembly is in the fully open position. In another embodiment, the opposing teeth  75  are positioned to engage each other when the pivotable shield assembly is in the partially open position. In yet another embodiment, the opposing teeth  75  are positioned to engage each other both when the pivotable shield assembly is in the partially open position and when it is in the fully open position. The pivotable hinge member  71  and the stationary hinge member  76  are held in a pivotable relationship to one another by pin  90  when it engages both pin hole  74  in stationary hinge member  76  and pin hole  73  in pivotable hinge member  71 . In  FIG. 17  pin  90  has a cylindrical shaft  91 , which allows for pivoting. To retain pin  90  in an operative position in both pin holes, either pin hole  73  or pin hole  77  has a diameter sufficiently small to frictionally engage cylindrical shaft  91  when it is inserted in the pin hole. Preferably, the pin hole on the pivotable hinge member frictionally engages the shaft  91  of pin  90  and reversibly retains it in position, whereas the diameter of pin hole  77  on the opposing hinge member  76  is sufficiently large so that the shaft  91  rotates freely in the pin hole  77 . The stationary hinge member  76  has a U-shaped clip  78  horizontally positioned below its outside face  79 . The U-shaped clip  78  has its respective side arms gapped for slideably receiving and frictionally engaging the corresponding upper and lower surfaces of a stationary base member (not shown). Although the gap in the U-shaped clip may be any size to slideably accommodate the thickness of the stationary base member, typically, the gap between the opposing arms of the U-shaped clip  78  is between ¼ inch and 1 inch. More typically, the gap is within the range of ⅜ inch to ¾ inch. 
     The left side hinge assembly  80  is just a mirror image of right side hinge assembly  70 . The left side hinge assembly  80  comprises pivotable hinge member  81 , stationary hinge member  86  and hinge pin  90 . As shown in  FIG. 17 , when pivotable hinge member  81  is symmetrical, it is identical to hinge member  71 . However, it is within the scope of this invention that the pivotable hinge members not be symmetrical, such as the pivotable hinge member  47  of  FIG. 7 . Pivotable hinge member  81  has side wall engaging surface  82 , pin hole  83  and teeth or ribs  85  as described for hinge member  71 . Stationary hinge member  86  has hinge engaging surface  84  with ribs or teeth  85  around pin hole  87  and U-shaped clip  88  for slideably receiving and frictionally engaging the corresponding upper and lower surfaces of a stationary base member (not shown). When pin holes  87  and  83  are aligned and hinge pin  90  is inserted in both pin holes, left side hinge assembly  80  is formed. The diameters of the pin holes  87  and  83  are as discussed for their mirror image members  73  and  77 . Right side hinge assembly  70  and left side hinge assembly  80  are typically matched so that their teeth  75  and  85 , respectively, engage at the same position or positions. Thus, in one embodiment, the opposing teeth  75  on the right ( 85  on the left) are positioned to engage on each respective side when the pivotable shield assembly is in the fully open position. In another embodiment, the opposing teeth  75  on the right ( 85  on the left) are positioned to engage on each respective side when the pivotable shield assembly is in the partially open position. In yet another embodiment, both sets of opposing teeth ( 75  and  85 ) are positioned to engage on their respective sides both when the pivotable shield assembly is in the partially open position and when it is in the fully open position. 
     Pivotable hinge members  71  and  81  are affixed to their respective sidewalls by any of the methods described herein for affixing the other pivotable hinge members. Such methods for attachment are well known in the art. In a preferred embodiment, the pivotable hinge members  71  and  81  are integrally attached to the side walls by being injection molded simultaneously with the side walls as a single unitary piece. When a pair of pivotable hinge members  70  and  80  are used to reversibly affix a shield assembly to a stationary base member, the stationary base member can be any base member as already described herein (including a platter or tray) and does not require a proprietary base member having hinge slot  3 , as in  FIG. 1 , or having a pair of opposing hinge slots  46  as in  FIG. 7 . Thus, in another embodiment, a resilient transparent shield assembly comprising a resilient transparent shield and opposing side walls having slideable hinge assemblies  70  and  80  is a stand alone invention in itself. This latter invention is usable with the consumer&#39;s existing base member, albeit a cutting board, a tray or a platter. Preferably, this resilient transparent shield assembly is a one piece device wherein the shield and side walls are assembleable and collapsible as described herein. 
     It is intended that the invention not be limited to the particular embodiments disclosed. The features in one embodiment are useful in any of the embodiments. It is intended that the invention include all embodiments falling within the scope of the appended claims.