Abstract:
Disclosed is a lid structure that includes an attachment tab connected to the lid by a living hinge. The attachment tab is configured to be attached to an external structure and the lid defines a ridge and a groove that surrounds the periphery of the lid structure except along the living hinge. Also discloses is a method of manufacturing the lid structure.

Description:
BACKGROUND 
       [0001]    Thermoforming is a manufacturing process where a plastic sheet is heated above its glass transition temperature, reformed into a desired shape in a mold, cooled below the glass transition temperature, removed from the mold and then trimmed to create a desired product. Twin sheet thermoforming expands on this process by bonding two separately thermoformed sheets together prior to cooling below the glass transition temperature to create more complex and/or thicker products. 
         [0002]    During thermoforming, the edges of the plastic sheet are generally restrained from moving while the inner portion of the sheet is stretched and reshaped by the mold, sometimes with a differential pressure (e.g. negative vacuum pressure on the mold side of the sheet and/or positive pressure on the opposite side) pushing the sheet against the mold. This leaves excess material around the periphery of the molded part that is generally removed to create the final desired product. This excess material is known as offal. Offal removal can be accomplished by placing the molded product, including offal, in a jig configured to secure the product while the offal is removed by die trimming, in mold trimming, CNC cutting or machining. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is a front perspective view of a sectional door incorporating multiple panel sections. 
           [0004]      FIG. 2  is a rear perspective view of the  FIG. 1  sectional door. 
           [0005]      FIG. 3  is a top view of a panel section of the  FIG. 1  sectional door. 
           [0006]      FIG. 4  is a side elevational view of the  FIG. 3  panel section. 
           [0007]      FIG. 5  is a front elevational view of the  FIG. 3  panel section. 
           [0008]      FIG. 6  is a bottom view of the  FIG. 3  panel section. 
           [0009]      FIG. 7  is a side cross sectional view of two panel sections joined together. 
           [0010]      FIG. 8  is an exploded side cross sectional view of  FIG. 7  taken within circle  8 . 
           [0011]      FIG. 9  is an enlarged cross sectional view of  FIG. 7  taken inside circle  9 . 
           [0012]      FIG. 10A  is a partial view, which in combination with  FIG. 10B , shows a process diagram detailing a method of thermoforming a panel section. 
           [0013]      FIG. 10B  is a partial view continued from  FIG. 10A  showing a second portion of the process diagram detailing the method of thermoforming a panel section. 
           [0014]      FIG. 11  is a side cross sectional view of a panel section in an as molded configuration. 
           [0015]      FIG. 12  is a side view of the  FIG. 11  configuration. 
           [0016]      FIG. 13  is a partial bottom view of the  FIG. 6  panel section shown in an intermediate condition with offal still attached. 
           [0017]      FIG. 14  is a partial side view of  FIG. 4  taken inside circle  14 . 
           [0018]      FIG. 15  is a partial cross sectional view of  FIG. 11  taken inside circle  15 . 
           [0019]      FIG. 16  is a partial cross sectional view of  FIG. 11  taken inside circle  16 . 
           [0020]      FIG. 17  is a side cross sectional view of two panel sections joined together showing flex in the living hinges during opening or closing of the sectional door. 
           [0021]      FIG. 18  is a perspective view of a toolbox lid. 
           [0022]      FIG. 19  is a top view of the  FIG. 18  toolbox lid. 
           [0023]      FIG. 20  is a back side elevational view of the  FIG. 18  toolbox lid. 
           [0024]      FIG. 21  is a bottom plan view of the  FIG. 18  toolbox lid. 
           [0025]      FIG. 22  is a front elevational view of the  FIG. 18  toolbox lid. 
           [0026]      FIG. 23  is a right side elevational view of the  FIG. 18  toolbox lid. 
           [0027]      FIG. 24  is a top plan view of the  FIG. 18  toolbox lid in an intermediate state of manufacture prior to removing the molding offal. 
           [0028]      FIG. 25  is a partial cross sectional view of  FIG. 23  taken inside circle  25 . 
           [0029]      FIG. 26  is a perspective view of a box incorporating the  FIG. 18  toolbox lid. 
           [0030]      FIG. 27  is a partial perspective view of the  FIG. 26  box taken inside circle  27 . 
           [0031]      FIG. 28  is a perspective view of the  FIG. 26  box showing the lid in an open position. 
           [0032]      FIG. 29  is an assembly view of the  FIG. 26  box. 
           [0033]      FIG. 30  is a cross sectional view of the  FIG. 26  box. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Reference will now be made to certain embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure and the claims are thereby intended, such alterations, further modifications and further applications of the principles described herein being contemplated as would normally occur to one skilled in the art to which this disclosure relates. In several figures, where there are the same or similar elements, those elements are designated with the same or similar reference numerals. 
         [0035]    Referring to  FIGS. 1 and 2 , a sectional door  50  is illustrated. Sectional door  50  includes a plurality of panel sections  52 , bottom panel section  54  and top panel section  56  attached together forming sectional door  50 . In this context, sectional door refers to a door that includes separate hinged panels that slide along a slide track or other guide to open and close the door. Common examples include overhead garage doors and overhead vehicle trailer doors. Sectional door  50  illustrated in  FIGS. 1 and 2  is configured as a vehicle trailer but the door described herein can be utilized for other desired door applications. Similarly, while overhead type doors are explicitly described herein, other sectional door configurations are intended to be covered, including section doors configured for side or bottom storage when opened. 
         [0036]    Panel sections  52 ,  54  and  56  are coupled together by attachment tab  62  that is a part of panel sections  52  and  54 . Details of this attachment are discussed below. 
         [0037]    Each of panel sections  52 ,  54  and  56  include recesses  64  on the right and left side as shown in  FIG. 2 . Recesses  64  may be configured to accept attachment hardware to couple sectional door  50  to guides or rollers to be used in conjunction with a track or other guide mechanism to hold sectional door  50  in position and permit opening and closing sectional door  50  as is known in the art. Bottom panel section  54  also includes recesses  66  and  68 . Recess  66 , in the illustrated embodiment, is configured to attach a handle for opening and closing sectional door  50  while recess  68  is configured to accept a latching mechanism to secure sectional door  50  in a closed position and to provide an optional locking mechanism. The particular configuration of recesses  64 ,  66  and  68  is dependent upon the desired hardware to be attached to sectional door  50  and can be varied or omitted as appropriate. 
         [0038]    Section door  50  includes outer surface  58  as shown in  FIG. 1  and inner surface  60  as shown in  FIG. 2 . The illustrated outer surface  58  is substantially flat and is adapted to receive painting, printing and/or signage for use in conjunction with a vehicle. 
         [0039]    The following includes a detailed description of panel section  52 . It should be understood that many of the features described below with regard to panel section  52  are equally applicable to bottom panel section  54  and top panel section  56 . Bottom panel section  54  and top panel section  56  are not otherwise described. 
         [0040]    Referring to  FIGS. 3-6 , panel section  52  is illustrated. Panel section  52  includes attachment tab  62 , panel portions  70  and  72 , living hinges  74  and  76 , outer surface  58 , inner surface  60  and ribs  80 . Living hinge  74  delimits attachment tab  62  and panel portion  72 . Living hinge  76  delimits panel portions  70  and  72 . As described below, attachment tab  62 , panel portions  70  and  72  and living hinges  74  and  76  are integrally formed as a monolithic structure. The top and bottom of attachment tab  62  and living hinge  74  are defined by edge  88 . In this context, “living hinge” refers to a thinned, flexible plastic hinge, that both joins two parts together and permits those parts to bend along the line of the hinge. Panel portion  52  is illustrated in a broken configuration to permit additional details to be shown. It should be understood that panel portion  52  has overall width  78  that is configurable to fit a desired door width. As discussed above, outer surface  58  of panel section  52  includes a substantially flat surface conversely inner surface  60  of panel section  52  includes a plurality of ribs  80  that are optionally included for stiffness and strength as further discussed below. 
         [0041]    As best shown in  FIG. 6 , panel portion  70  defines receiver portion  82  that is configured to receive attachment tab  62 . Attachment tab  62  includes a plurality of fastener holes  84  spaced along its length while receiver portion  82  includes a plurality of fastener holes  86  spaced along its length mirroring the positions of fastener holes  84 . Comparison of  FIGS. 3 and 6  show that fastener holes  84  are through holes while fastener holes  86  only pass through inner surface  60  but do not penetrate outer surface  58 . This is discussed in additional detail below. 
         [0042]    Referring now to  FIGS. 7-9 , two panel sections  52  are illustrated coupled together by fastener  98 . While  FIGS. 7 and 9  illustrate a cross section and thus show only a single fastener  98 , it should be understood that a plurality of fasteners  98  are utilized to fasten panel sections  52  together via fastener holes  84  and  86  as discussed above. As previously discussed, each panel section  52  includes panel portions  70  and  72  separated by living hinge  76  and living hinge  74  separates attachment tab  62  from panel portion  70 . 
         [0043]    Outer surface  58  includes outer surface  94  on panel portion  70  and outer surface  96  on panel portion  72 . In the illustrated cross section, panel portion  52  includes outer sheet  100 , inner sheet  102 , and weld seam  108 . Panel portion  70  defines longitudinal axis  112  and panel portion  72  defines longitudinal axis  114 , outer sheet  100  defines bearing surfaces  116  and  118  and recesses  120  and  122 . Inner sheet  102  defines bearing surfaces  104  and  106  and recess  110 . 
         [0044]    When assembled as sectional door  50 , panel sections  52  are arranged in an abutting relationship with bearing surface  104  directly abutting and bearing against bearing surface  106 . When aligned and arranged in this way, fastener holes  84  and  86  are configured to align permitting placement of fastener  98 . As discussed above, fastener  98  can be configured to pass through attachment tab  62  and only inner sheet  102  to secure the two panel sections  52  together without affecting outer sheet  100 . 
         [0045]    In the illustrated embodiment, fastener  98  is a rivet type fastener that has a blind side expander that is insertable through a hole and then later expanded to complete the fastener, as is well known in the art. Other embodiments (not illustrated) use other types of fasteners as desired. For example, fastener hole  86  could include an integral nut body, and fastener  98  could include a threaded bolt. In yet other embodiments, attached tab  62  could be joined to receiver portion without a mechanical fastener by welding or adhesive. In yet other embodiments (not illustrated), fastener  98  could pass through outer sheet  100 . Any desired method may be used to join panels together. 
         [0046]    As discussed in greater detail below, in the illustrated embodiment, outer sheet  100  and inner sheet  102  are thermoformed together and include welded seam  108 . Welded seam  108  is separated from bearing surface  106  by recess  110  with receiver portion  82  and weld seam  108  configured so that welded seam  108  does not contact bearing surface  104  (or any other part of the attached panel section  52 ). 
         [0047]    Referring to  FIG. 9 , an enlarged view proximate to living hinge  76  is illustrated. Bearing surfaces  116  and  118  are configured to abut and bear against each other when longitudinal axes  112  and  114  are aligned as illustrated. Panel portions  70  and  72  also define recesses  120  and  122  that separate bearing surfaces  116  and  118  from living hinge  76 . Recess  120  and  122  are configured to never contact each other. 
         [0048]    Bearing surfaces  104 ,  106 ,  116  and  118  are configured to support and transfer compressive loads across the illustrated abutting surfaces. 
         [0049]    Referring now to  FIG. 10 , process  200  is illustrated. Process  200  details many process steps that could be used to thermoform panel section  52 . However, process  200  is not all-inclusive and many additional steps would be apparent to a person of ordinary skill in the art. The steps described in process  200  generally involve a multi-station thermoforming machine that includes at least four stations that move plastic sheets between the four stations by a set of clamp frames that rotate between the four positions. The four positions include a load/unload station, a first preheat oven, a second final heat oven and a molding position where thermoforming takes place. The manufacturing process described herein is related to making a single unit. It should be understood that this manufacturing process is intended to be used as a continuous process where the actions described for each station repeatedly reoccur, facilitating continuous production of manufactured parts. Furthermore, while a multi-station thermoforming machine is described, process  200  is intended to be adapted to whatever type of thermoforming machine is desired with appropriate modifications to account for known differences. Similarly, process  200  is intended to be adaptable by persons skilled in the art to other types of multi-station thermoforming machines that are not explicitly described, for example, thermoforming machines that clamp two sheets in a single clamp frame, as known in the art. 
         [0050]    In any event, process  200  begins with step  202 . In step  202  inner sheet  102  is loaded onto a load table in the load/unload station. In step  204  the load table is moved up to bring inner sheet  102  into the boundaries of a first clamp frame and in step  206  the clamp frame clamps inner sheet  102  around the periphery to secure inner sheet  102  within the clamp frame. The load table is then lowered back down to the load position. 
         [0051]    Process  200  continues with step  208  where the clamp frames are rotated moving the first clamp frame into the preheat oven and moving a second clamp frame into position in the load/unload station and in step  210 . In step  210  outer sheet  100  is loaded onto the load table and in step  212  the load table is moved up, positioning outer sheet  100  within the second clamp frame. In step  214 , outer sheet  100  is clamped within the second clamp frame and the load table is lowered. 
         [0052]    Process  200  continues with step  216  where the clamp frames are rotated again, moving the first clamp frame into the final heat oven and the second clamp frame into the preheat oven. This is followed by step  218  where the clamp frames are rotated yet again moving the first clamp frame into the forming area and the second clamp frame into the final heat oven. By this time, inner sheet  102  should be heated above its glass transition temperature. Immediately after moving the first clamp frame in the forming area, a bottom mold is moved into contact with the first sheet in step  220 . In step  222 , a vacuum assist is utilized to form inner sheet  102  to the bottom mold. After inner sheet  102  is formed to the bottom mold then inner sheet  102  is released from the first clamp frame in step  224  and the bottom mold and inner sheet  102  are lowered down in step  226 . 
         [0053]    This is followed by step  228  where the clamp frames are rotated again, moving the second clamp frame into the forming area where the top mold is lowered down into contact with outer sheet  100  in step  230  and then subsequently vacuumed formed to conform to the shape of the top mold in step  232 . Outer sheet  100  continues to be retained in the second clamp after being formed to conform to the top mold. 
         [0054]    In step  236 , the top and bottom molds are brought together bringing portions of the inner sheet  102  into contact with the outer sheet  100 . This is followed by step  240  where the top and bottom molds are locked together with bayonets and air bags are inflated to create a tight seal and clamp the top and bottom molds together. Next in step  242 , blow needles are extended through inner sheet  102  and pressurized as is applied through the blow needles to the spaces between inner sheet  102  and outer sheet  100 . This could include slightly pressurizing the space and also removing hot air from the space by opening some of the needles to atmosphere while pressurizing other vents. This could also include sequentially applying pressure through the needles at high and low pressure while some of the needles are open to atmosphere. Generally, pressurized air is injected in approximately half of the needles while the remaining needles are vented to atmosphere. This creates a small positive pressure and an air flow that helps remove hot air captured between outer sheet  100  and inner sheet  102 . In other instances, high pressure air is injected to assist in forming the part against the molds for a portion of step  242 . 
         [0055]    This is followed by equalizing the pressure in the space between the first and second sheets with atmospheric pressure through the needles in step  244  to prevent ballooning or collapse of the part due to differential pressure between the interior space and the atmosphere. This also allows any heat gradients in the space between the sheets to equalize. The blow needles are then retracted from inner sheet  102 . Note that while process  200  describes the blow needles only extending through inner sheet  102 , the blow needles can extend through any surface desired, including outer sheet  100 . 
         [0056]    After sheets  100  and  102  are sufficiently cooled, bonded and welded together, the top and bottom molds are opened in step  245 . This is followed by step  246  where the clamp frames are rotated, moving the second clamp frame into the load/unload station where, in step  247 , the second clamp frame is opened, releasing the second sheet and formed panel section  52  is removed. Immediately after removing the formed panel section  52 , living hinge(s)  74  and  76  are flexed in step  248 . To facilitate this, edges  88  may optionally be die cut between the top and bottom molds in step  240 . After the formed part is removed it is clamped in a jig and the offal is machined off in step  250 , completing panel section  52 . 
         [0057]    Referring now to  FIGS. 11 and 12 , panel section  52  is illustrated as oriented during thermoforming in process  200 . (Note that  FIGS. 11 and 12  are rotated 90 degrees to better fit on the page.) In one manufacturing orientation, the illustrated panel section  52  would be orient in a “V” configuration, with living hinge  76  positioned below living hinge  74 . 
         [0058]      FIG. 11  illustrates a cross sectional view of panel section  52  showing melt bonds  130  and  132  between outer sheet  100  and inner sheet  102 . Melt bonds  130  are positioned at the top of ribs  80  and represents an optional technique to stiffening panel section  52  by increasing the points of contact between outer sheet  100  and inner sheet  102  and by providing increased web structures between outer sheet  100  and inner sheet  102 . Melt bond  132  is on the outer edge near receiver portion  82  and corresponds to weld seam  108  prior to machining. 
         [0059]    Living hinges  74  and  76  also represent a point of melt bonding between outer sheet  100  and inner sheet  102 . However, the relative force applied to the areas of living hinges  74  and  76  are substantially higher than melt bonds  130  and  132  to facilitate forming living hinges  74  and  76 . In process  200  this is accomplished by including a movable insert in the top and/or bottom molds that&#39;s position can be adjusted along the length of living hinges  74  and  76 , for example by shimming the movable insert. This permits control of the thickness of living hinges  74  and  76 . 
         [0060]    As shown in  FIG. 11 , longitudinal axis  112  and  114  of panel portions  70  and  72  are angled apart by mold angle  134  during thermoforming. In the illustrated embodiment, mold angle  134  is equal to approximately 140°. In other embodiments (not illustrated) mold angle  134  could be between approximately 130° and 150°. 
         [0061]    As shown in  FIG. 12 , bearing surface  104  is angled from longitudinal access  112  by angle  136 . In the illustrated embodiment, angle  136  is equal to approximately 70°. In other embodiments, angle  136  may be equal to approximately half of mold angle  134 . 
         [0062]    Referring to  FIG. 13 , a partial bottom view of panel section  52  is illustrated showing panel section  52  in an incomplete state as it may appear after step  246  in procedure  200  but before steps  248  or  250 . As illustrated in  FIG. 13 , panel section  52  includes offal  140 , weld seam  142 , vent  144 , receptor  146 , needle hole  148  and die cut score line  150 . Offal  140  includes the portions of inner sheet  102  (and outer sheet  100  which is not visible in this view but is located on the opposite side) that is gripped by the clamp frames and which provide a reservoir of plastic material for draw down during molding. Offal  140  includes most of weld seam  142  that defines the outer periphery of panel section  52 . Vent  144  and receptor  146  are molded structures that extend into the offal area to provide venting of the interior spaces defined by attachment tab  62 . Receptor  146  is configured to receive a blow needle in step  242  of procedure  200 . Vent  144  provides an internal passageway between receptor  146  and the interior space between outer sheet  100  and inner sheet  102  in attachment tab  62 . Needle hole  148  depicts the hole where the blow needle extended through inner sheet  102 . 
         [0063]    Also shown in  FIG. 13  is die cut score line  150  along the bottom of attachment tab  62  and living hinge  74 . Die cut score line  150  is located in weld seam  142  and may represent either a thinned portion of weld seam  142  or a through cut. Panel section  52  shown in  FIG. 13  is machined in step  250  of procedure  200  to the final configuration illustrated in  FIGS. 3-6  by machining or cutting off offal  140  along weld seam  142 . Vent  144  and interceptor  146  are machined or cut off and removed with the offal. 
         [0064]    Referring to  FIG. 14 , partial side view of panel section  52  is illustrated mirroring the portion of panel section  52  shown in  FIG. 13 . As shown in  FIG. 14 , machining or cutting vent  144  off leaves passage  152  through the sidewall of attachment tab  62 . 
         [0065]    Referring to  FIG. 15 , an enlarged view of the  FIG. 11  cross section of panel section  52  proximate to living hinge  76  is illustrated. As shown in  FIG. 15 , living hinge  76  includes thickness  160 , bottom radius  162 , top radius  164 , with bearing surface  116  having a length  166  and bearing surface  118  having length  168 . In the illustrated embodiment, thickness  160  is approximately equal to 0.030 inches. In other embodiments, thickness  160  can vary between approximately 0.028 and 0.040 inches thick. In the illustrated embodiment, radiuses  162  and  164  are both equal to approximately 0.063 inches and lengths  166  and  168  are both equal to approximately 0.29 inches. In other embodiments, lengths  166  and  168  can vary between approximately 0.10 and 0.30 inches. In the illustrated embodiment, panel width  170  is equal to approximately 1.5 inches. 
         [0066]    Referring to  FIG. 16 , an enlarged view of  FIG. 11  proximate to living hinge  74  is illustrated showing living hinge thickness  172 , top radius  176  and bottom radius  174 . In the illustrated embodiment, thickness  172  is approximately equal to 0.030 inches. In other embodiments, thickness  172  can vary between approximately 0.028 and 0.040 inches thick. In the illustrated embodiment, radiuses  174  and  176  are both equal to approximately 0.063. 
         [0067]    Referring to  FIG. 17 , a cross sectional view of two panel sections  52  is illustrated with panel sections  52  joined together at attachment tab  62  and receiver portion  82  as discussed above. The upper panel section  52  is shown flexed through an approximate 90° bend as would be typical when opening or closing most sectional doors. In particular, in the upper panel section  52 , longitudinal axes  112  and  114  are angled apart by approximately 135° while longitudinal axis  114  on the upper panel section  52  and longitudinal axis  112  on the lower panel section  52  are also angled apart by approximately 135°. Bearing surfaces  116  and  118  on the upper panel section do not bear against each other. Similarly bearing surface  106  on the upper panel section  52  does not bear against bearing surface  104  on the lower panel section  52  (as compared to what is illustrated in  FIGS. 7-9 ). 
         [0068]    Referring to  FIGS. 18-23 , lid  300  is illustrated. Lid  300  is a toolbox lid for a truck toolbox. Lid  300  is thermoformed from plastic sheets  302  and  304  bonded together along bond flange  306 . Lid  300  includes top surface  308 , bottom surface  310 , body  311 , tab  314  which is separated from body  311  by living hinge  316 . Body  311  has an internal cavity  312  and tab  314  has internal cavity  313 . Internal cavities  312  and  313  represent the space between sheets  302  and  304  when they are thermoformed together. Tab  314  also includes a plurality of vents  317 . As discussed in greater detail below, vents  317  are molded structures that extend into the offal area (removed in  FIGS. 18-23 , shown in  FIG. 24 ) to vent internal cavity  313 . 
         [0069]    As best illustrated in  FIG. 21 , bottom surface  310  includes a plurality of ribs  318  that are optionally included for stiffness and strength. Ribs  318  may provide web structures across bottom surface  310  that may serve to increase the overall strength and stiffness of bottom surface  310  and body  311 . 
         [0070]    Also illustrated in  FIG. 21  are a plurality of blow needle recesses  319  and holes  320 . Holes  320  depict the hole left when a blow needle is extended through plastic sheet  304  during a thermoforming process to vent and/or move a vent transfer fluid through internal cavity  312 . 
         [0071]    Referring now to  FIG. 24 , lid  300  is illustrated in an intermediate manufacturing condition prior to removing the molding offal. Unfinished lid  321  includes offal  322 , chamber  324  and vents  326 . Chamber  324  is defined in the offal region of plastic sheets  302  and  304  and is bound by bond flange  306 . Vent  326  is also defined by plastic sheets  302  and  304 . Vent  326  connects the interior space of chamber  324  with internal cavity  313  in tab  314 . Chamber  324  is configured and arranged to receive one or more blow needles during the molding process. The blow needles can then be used to vent internal cavity  313  and/or move a vent transfer fluid, such as air, through vents  326  and internal cavity  313  to aide in cooling plastic sheets  302  and  304  defining tab  114 . 
         [0072]    As best shown in  FIG. 23 , tab  314  is dimensionally configured too small to reliably insert blow needles into internal cavity  313 . Chamber  324  provides a structure that is sufficiently large to receive a blow needle and vents  326  fluidly connect the two. In one embodiment, an individual chamber  324  can receive blow needles proximate to each vent  326 . In one embodiment, some blow needles can provide a supply of heat transfer fluid while the remaining blow needles can withdraw the heat transfer fluid to provide a flow through internal cavity  313 . In other embodiments, the central chamber  324  illustrated in  FIG. 24  could receive one set of blow needles that supply heat transfer fluid while the two chambers  324  positioned on the outside could receive blow needles to withdraw the heat transfer fluid to provide a flow through internal cavity  313 . 
         [0073]    Referring now to  FIGS. 26-30 , box  400  is illustrated. Box  400  illustrates one application of lid  300  where lid  300  is coupled to an external structure to complete box  400 . Box  400  includes lid  300 , base  402 , front panel  404 , side panels  406 , back panel  408  and spring  410 . Back panel  408  also includes channel  112  constructed to receive tab  314  to couple lid  300  to back panel  408  and box  400 . In the illustrated configuration, channel  412  receives tab  314  by sliding tab  314  longitudinally along the length of channel  412 . A plurality of fasteners  414  optionally longitudinally secure tab  314  in channel  412  by passing through both channel  412  and tab  314 . In the illustrated configuration, box  400  is configured as a truck bed toolbox mountable in a truck bed between bed side rails. However, box  400  could be configured as desired for a other applications. 
         [0074]    Hinge  316  on lid  300  may have resiliency sufficient to support the weight of lid  300  when tab  314  is coupled to channel  412  to the extent that lid  300  does not close into contact with front panel  414  without an additional downward force applied to lid  300  (when oriented as shown in  FIGS. 26-28 ). Spring  410  may optionally be added to bias lid  300  upwards to maintain lid  300  in an open position unless a closing force is applied to lid  300  sufficient to overcome spring  410  and the resiliency of hinge  316  to close lid  300  into contact with front panel  404 . A latching or locking feature may be optionally included to maintain lid  300  in a closed position. 
         [0075]    This disclosure serves to illustrate and describe the claimed invention to aid in the interpretation of the claims. However, this disclosure is not restrictive in character because not every embodiment covered by the claims is necessarily illustrated and described. All changes and modifications that come within the scope of the claims are desired to be protected, not just those embodiments explicitly described.