Abstract:
The present invention provides a system which includes injection molded roof panels, header assemblies and ridge caps having integrated connectors which combine to form a family of variously sized roof assemblies for utility enclosures. The injection molding facilitates integrally formed connectors so that the roof panels, header assemblies and ridge caps interlock with one another without the need for separate connectors.

Description:
RELATED APPLICATIONS 
     This application is a continuation of utility patent application Ser. No. 11/216,929 entitled Plastic Expandable Utility Shed filed Aug. 30, 2005, now U.S. Pat. No. 7,581,357 the contents of which are herein incorporated by reference in their entirety. This application is also related to Ser. No. 29/230,885 filed May 27, 2008, now U.S. Design Pat. No. D529,623, and Ser. No. 29/230,978 filed May 27, 2005, now U.S. Design Pat. No. D525,715, the contents of which are herein incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to plastic utility sheds, and more specifically to a modular roof system constructed of injection molded plastic panels for creating plastic utility shed roofs of various sizes from standardized components. 
     BACKGROUND OF THE INVENTION 
     Utility sheds are necessary for lawn and garden care, as well as general all-around home storage space. Typically, items such as garden tractors, snow blowers, tillers, ATVs, motorcycles, lawn tools and the like are stored within utility sheds for the convenience of the homeowner. 
     The prior art has proposed a number of different panel systems, or kits, comprising blow molded and/or extruded panels which are combined with connector members for forming storage structures, e.g. utility sheds. Unfortunately, blow molding and/or extrusion of panels for utility sheds has resulted in shortcomings within the state of the art products. For example, due to the nature of the manufacturing process, blow molded and/or extruded plastic components cannot be formed with the intricate shapes and/or sharp corners required for integrated connectors. Therefore, these systems require extruded metal or plastic connector members having a specific cross-sectional geometry that facilitates an engagement between the blow molded or extruded panels to complete the structure. 
     A particularly common structure for the connector members is one having an I-beam cross section. The I-beam defines free edge portions of the connector member which fit within appropriately dimensioned and located slots in the panel members. U.S. Pat. No. D-371,208 teaches a corner extrusion for a building sidewall that is representative of the state of the art I-beam connector members. The I-beam sides of the connector engage with the peripheral edge channels of a respective panel and thereby serve to join such panels together at right angles. Straight or in-line versions of the connector members are also included in the kits to join panels in a coplanar relationship to create walls of varying length. 
     Another drawback associated with blow molded panels is the requirement of an inner and an outer wall. The inner and outer walls are a necessary product of the blow molding manufacturing process. While the inner wall may add some rigidity to the panels, it also adds a significant amount of weight and dramatically increases the volume of plastic necessary to form a panel of a given size when compared to other methods of manufacturing, such as injection molding. 
     A further drawback associated with blow molded panels relates to accurate control of wall thickness throughout the panels. The blow molding process does not allow the wall thickness of the panels to be accurately controlled. Once the molten plastic is conveyed to the tooling, there is minimal control over where the plastic flows during formation of the panel. Also, the blow molding process does not allow the intentional formation of thick and thin sections within a single panel for engineered rigidity at the points of high stress or high load concentration. 
     Extruded panels generally require hollow longitudinal conduits for strength. Due to the nature of the manufacturing process, the conduits are difficult to extrude in long sections for structural panels. Thus, they also require connectors to achieve adequate length for utility shed roofs. A common structure for connecting extruded members has a center I-beam with upper and lower protrusions for engaging the conduits. Wall panels utilizing these connectors are vulnerable to buckling under loads and may have an aesthetically unpleasing appearance. Moreover, roof loads from snow and the like may cause such walls to bow outwardly due to the clearances required between the connectors and the internal bores of the conduits. U.S. Pat. No. 6,250,022 discloses an extendable shed utilizing side wall connector members representing the state of the art. The connectors have a center strip with hollow protrusions extending from its upper and lower surfaces along its length; the protrusions being situated to slidably engage the conduits located in the side panel sections to create the height needed for utility shed walls. 
     The aforementioned systems can also incorporate roof and floor panels to form a freestanding enclosed structure such as a small utility shed. U.S. Pat. Nos. 3,866,381; 5,036,634; and 4,557,091 disclose various systems having inter-fitting panel and connector components. Such prior art systems, while working well, have not met all of the needs of consumers to provide the structural integrity required to construct larger sized structures. 
     Larger structures must perform differently than small structures. Large structures must withstand increased wind and snow loads when compared to smaller structures. Paramount to achieving these needs is a panel system which eliminates the need for extruded connectors to create enclosure walls which resist panel separation, buckling, and racking. A further problem is that the wall formed by the panels must tie into the roof and floor in such a way as to unify the entire enclosure. Also, from a structural standpoint, the enclosure should include components capable of withstanding the increased wind, snow, and storage loads required by large structures. 
     Therefore, what is needed in the art is an injection molded modular roof system for utility enclosures. The modular roof system should achieve objectives such as light weight single wall construction. The construction of the panels should eliminate the need for extruded I-beam connectors to create a roof assembly which resists panel separation, buckling, and racking. The roof assembly should be capable of withstanding the wind and snow loads typically associated with utility enclosure roofs. 
     There are also commercial considerations that must be satisfied by any viable utility shed enclosure system or kit; considerations which are not entirely satisfied by state of the art products. The roof assembly must be formed of relatively few component parts that are inexpensive to manufacture by conventional techniques. The roof assembly must also be capable of being packaged and shipped in a knocked-down state. In addition, the roof assembly must be modular and facilitate the creation of a family of roof assemblies that vary in size but which share common, interchangeable components. 
     Finally there are ergonomic needs that a roof assembly must satisfy to achieve acceptance by the end user. The roof assembly must be easily and quickly assembled using minimal hardware and requiring a minimal number of tools. In addition, the roof assembly must not require excessive strength to assemble or include heavy component parts. Moreover, the roof assembly must assemble together in such a way so as to not detract from the internal storage volume of the resulting enclosure or otherwise negatively affect the utility of the structure. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system including injection molded roof panels, headers, and ridge caps having integrated connectors which combine to form a family of variously sized roofs for utility enclosures. The roof panels, headers, and ridge caps are formed of injection molded plastic to create light-weight components having integrally formed ribs and gussets for strength and integrity. The injection molding also facilitates integrally formed connectors so that the panels, headers and ridge caps interlock with one another without the need for separate connectors. In addition, the ridge caps and/or roof panels may be formed of translucent plastic for natural lighting. 
     Accordingly, it is a primary objective of the instant invention to provide a plastic utility roof assembly. 
     It is a further objective of the instant invention to provide a plastic roof assembly which utilizes roof panels and ridge caps having single wall construction with integrally formed ribs and gussets for a lightweight yet robust roof assembly. 
     It is yet another objective of the instant invention to provide a plastic roof assembly which accommodates injection molding plastic formation of the components for increased structural integrity. 
     It is a still further objective of the invention to provide a modular header system which allows standard components to be utilized for different width roofs. 
     Still another objective of the instant invention is to provide a roof system in which the components include integrally formed connectors. 
     Yet another objective of the instant invention is to provide a roof system which includes components having predetermined sizes for creating roofs of varying dimensions using common components. 
     Still yet another objective of the instant invention is to provide a roof assembly which reduces the number of components required to assemble a roof and simplifies construction. 
     Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a front perspective view of an enclosure comprising an assembled wall system, roof headers, and a ridge cap. 
         FIG. 2  is a front perspective view of an enclosure comprising an assembled wall system, headers and the left half of the roof assembly. 
         FIG. 3  is an exploded view of a complete roof assembly. 
         FIG. 4  is a front perspective view of a two piece header. 
         FIG. 5  is a rear perspective view of a two piece header. 
         FIG. 6  is a front perspective exploded view of a two piece header with a strap support. 
         FIG. 7  is a front perspective view of a three piece header. 
         FIG. 8  is a rear perspective view of a three piece header. 
         FIG. 9  is a front perspective exploded view of a three piece header with a strap support. 
         FIG. 10  is a bottom view of a three piece header. 
         FIG. 11  is a perspective view of the back side of a header and the underside of the roof panels. 
         FIG. 12  is a perspective view of the front side of a header and the underside of roof panels. 
         FIG. 12A  is an enlarged view of the connection between the header and a roof panel. 
         FIG. 13  is a perspective view of the top of the roof panels and a section of the ridge cap. 
         FIG. 14  is a perspective view of the underside of the roof panels and a section of the ridge cap. 
         FIG. 15  is an enlarged view taken along line  2 - 2  of  FIG. 14  illustrating the connection between the ridge cap and a roof panel. 
         FIG. 16  is a perspective view of the connection between a roof panel and a wall panel. 
         FIG. 16A  is an enlarged view taken along line  3 - 3  of  FIG. 16  illustrating the connector which joins a roof panel to a wall panel. 
         FIG. 17  is a perspective view of an assembled roof and wall panel. 
         FIG. 17A  is an enlarged view taken along line  4 - 4  of  FIG. 17  illustrating the assembled connection between a roof panel and a wall panel. 
         FIG. 18  is a perspective view of an assembled roof and wall panel including a roof support. 
         FIG. 18A  is a enlarged view of the connector between a roof panel and the roof support. 
         FIG. 19  is a perspective view of two different roof panels utilized for enclosures of different widths. 
         FIG. 20  is an enlarged view of the connection between two roof panels. 
         FIG. 21  is an enlarged view of one roof panel of the connection shown in  FIG. 20 . 
         FIG. 22  is a section view taken along line  1 - 1  of  FIG. 13  illustrating the overlapping connection between the roof panels. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
       FIGS. 1-3  show perspective views of a heavy duty plastic utility enclosure, generally referenced as  10 , constructed according to a preferred embodiment of the present invention. The roof assembly generally includes header assemblies  410 , roof panels  460 , roof supports  520 , and a ridge cap assembly  530  which are shown in an exploded view in  FIG. 3 . The header assembly is a truss like structure molded with an aesthetically pleasing generally smooth wall  412  on its outer surface (FIGS.  3 , 6 , 7 , and  9 ) and integrally formed box bracing  414  ( FIGS. 4-9 ) and a plurality of pockets  416  constructed and arranged to accept roof support members  470  on its inner surface. In the preferred embodiment the header assembly is constructed of a center member  418  and a pair of outer members  420  ( FIG. 3 ). This type of construction permits the center member to be added or removed to construct different size enclosures while the outer members remain the same. Each member of the header assembly includes an upper surface  422  and a lower surface  424 . The lower surface  424  includes a plurality of inwardly extending engagement sockets  426  constructed and arranged to cooperate with removable and replaceable bosses  428  and/or door hinge pins  430 . The bosses  428  or hinge pins  430  are slid into their respective engagement sockets  426  until the integrally formed spring tabs  432  ( FIGS. 6 and 9 ) engage corresponding apertures formed in the engagement sockets. The end surfaces  434 ,  436  of the header members includes means to connect them together illustrated herein as a plurality of outwardly extending, inter-fitting tubes  438 . The tubes are constructed and arranged to extend into a socket  439  formed in an adjacently positioned header member until integrally formed spring locks  440  ( FIG. 8 ) engage a corresponding aperture. This construction provides a load distributing connection between the header members that prevents separation and bowing of the assembly under load. In addition, the design provides a sealed connection between the panels preventing weather and insect infiltration. The resultant header created by the combination of the interlocking members benefits from high structural integrity and reliable operation. 
     Referring to  FIGS. 4-6 , a two piece header embodiment is illustrated. With this embodiment additional means are provided for attaching the header members together illustrated herein as a C-shaped clip  444 . The C-shaped clip is inserted into apertures  446  provided in each of the header members ( FIG. 5 ). The C-shaped clip is provided to prevent separation and provide load support integrity to the header assembly. For additional support ad rigidity the header assembly is constructed and arranged to cooperate with a metal support member  448 . The metal support member is attached to the header members with fasteners  450  and anchors  452 . The anchors are inserted through the apertures  454  on the rear side of the header members ( FIG. 5 ). In this manner  FIGS. 8 and 9  show how the strap is employed with a three piece header assembly. 
     The headers are attached to the wall assemblies by sliding the bosses  428  into sockets (not shown) positioned in the top portion of the wall panels until the integrally formed spring clips  442  ( FIG. 3 ) engage apertures formed in the sockets. The result is a positive lock that maintains alignment of the wall panels in the same plane and prevents bowing or bending of one panel relative to another one. 
     Referring to  FIGS. 1-3  and  5 , at least three roof supports  520  are inserted into their respective pockets  416  in each of the headers and may optionally be secured in place with suitable fasteners. The roof supports are preferably constructed of a metal such as steel, but may be constructed of other materials well known in the art capable of providing structural support to the roof assembly. Such materials may include but are not limited to wood and/or plastic as well a suitable combinations thereof.  FIG. 1  illustrates the placement of the support beams in the headers of the preferred embodiment. 
     Referring to  FIGS. 3 and 13  roof panels  460  are formed as either a central roof panel  462  or an end roof panel  464 . Each central roof panel has a top surface  466 , a bottom surface  468 , a first locking edge  470 , a second locking edge  472 , a third locking edge  474  and a closed edge  476 . Along the bottom surface  468  adjacent to the closed edge  476  is another connection means illustrated herein as a plurality of sockets  478  constructed and arranged to receive roof connectors  480  ( FIGS. 16 and 17 ). The roof connectors are constructed and arranged to cooperate with pockets (not shown) located in the top portion of the wall panels as well as the sockets  478  located on the lower surface of the roof panels. A series of spaced apart structural ribs  482  extend across the bottom surface of each roof panel to provide rigidity and increased weight carrying capacity to the roof assembly. The first  470  and second  472  locking edges of the roof panel include another connection means illustrated herein as a W-shaped overlapping connection  484  ( FIG. 22 ). The distal portion  486  of the first locking edge  470  of the overlapping connection includes a plurality of ramp-locks  488  constructed and arranged to cooperate with apertures  490  formed into the second locking edge overlapping connection. The W-shaped overlapping connection provides a water resistant seal between the panels and prevents the panels from bowing or separating under wind or snow loads. The second locking edge  472  further includes a downwardly extending wave shaped rib  492  ( FIG. 21 ). This rib is constructed and arranged to fit into a corresponding trough  494  formed on the first locking edge  470  ( FIG. 20 ). The connection of the wave shaped rib  492  and corresponding trough  494  provides an additional water resistant seal between the panels. Any water that may enter the trough flows downwardly along the trough and out through drain  496  ( FIG. 20 ). Drain  496  is located outside of the walls so that water is prevented from entering the enclosure. 
     Sockets  478  located on the lower surface of the roof panels comprise two sockets members ( FIG. 20 ). Each socket member is located along a locking edge of a roof panel (FIGS.  16 , 17 , and  20 ). Roof connectors  480  are formed with two upwardly extending members  500  and a lower member  502  which spans members  500 . The upwardly extending members are provided with ramp-locks  504  and the lower member is provided with two ramp-locks  506 . The connectors  480  are constructed and arranged to allow the upwardly extending members to slide into sockets  478  and the lower member to slide into a socket on the top portion of a wall panel ( FIGS. 16 and 17 ). The ramp-locks engage apertures  508  in socket  478  and ramp-locks  506  engage apertures  510  in the wall panel socket. Another type of roof connector  512  also slides into sockets  478  which are located on the lower side of the roof panel and spaced between the ends of the roof panels as shown in  FIG. 18 . The lower portion of connector  512  is provided with a groove which engages roof supports  520  to provide support for the roof panel along its length. Connectors  512  are provided with ramp locks  514  which engage apertures  508  in sockets  478  to provide a locking connection. The connectors  512  and roof supports  520  provide roof support for additional snow loads. 
     The end roof panels  464  are similar to the central roof panels in that they have a top surface, a bottom surface, sockets  478  on the bottom surface located along either a first or second locking edge, a third locking edge and a closed end. They differ from the central roof panels in that they are not as wide and have a channel  516  located along either a first or second locking edge. In place of a locking edge adjacent the channel there is a smooth edge surface  518  ( FIGS. 3 and 12 ). This edge extends beyond the header and presents an aesthetically pleasing surface. The width of channel  516  is the same as the depth of the header assemblies  410  so as to form a connection between the roof and the header assemblies and create a weather resistant seal between the two members. Channels  516  are also include apertures  522  which engage ramp-locks  524  located along the upper edge of the header assemblies ( FIG. 12 ) to secure the end roof panels to the header assemblies. 
     The central and end roof panels are available in at least two different lengths as shown in  FIG. 19 . The pattern of the structural ribs  482  on the bottom surface of the roof panels is selected so that the shorter roof panel can be formed without retooling. As can be seen in  FIG. 14  if the formation of the roof panel is stopped at the transverse rib  482  a shorter roof panel, with the proper structural elements, will be the result. 
     The roof assembly also includes a ridge cap assembly  530  which is formed from a plurality of like constructed ridge cap members  531  ( FIG. 13 ). Each ridge cap member includes an integrally formed tubular connector  533  at one end thereof and an integrally formed aperture  532  at the opposite end thereof. The tubular connector  533  of one ridge cap member engages the aperture  532  of an adjacent ridge cap member thereby interlocking the members together. There are also two ridge cap members which cooperate with the end roof panels and header assemblies ( FIG. 3 ) and include apertures  536  which cooperate with ramp-locks  524  formed on the header assemblies ( FIG. 12 ) to secure the ridge cap members to the header assemblies. Each of these ridge cap members is formed with an end portion which corresponds to the edge surface  518  of the end roof panels so as to present an aesthetically pleasing edge surface when located adjacent thereto. The ridge cap members may be made from a translucent material to enhance natural lighting of said enclosure. 
     The third locking edge of each roof panel includes an interlocking tubular connection  526  which is constructed and arranged to cooperate with a conjugately shaped receiver  528  formed in the ridge cap members  531  ( FIG. 3 ) to join roof panels on opposite sides of the roof and to create a weather resistant seal. The tubular connection  526  includes integrally formed ramp-locks  534  which engage corresponding apertures  536  in the ridge cap members ( FIG. 15 ). The length of each ridge cap corresponds to the width of a roof panel. 
     All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. 
     It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein. 
     One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.