Abstract:
An apparatus to aid in the moving and transportation of heavy doors or large sheet-type materials comprises a pair of joined “L”-shaped brackets mounted upon a folding hinge. The hinge allows the weight of the carried material to fold the apparatus inwardly thus securely gripping the loaded items within. Each “L”-shaped bracket comprises a front plate which secures the load in a lower corner area while allowing the user to lift and support the other bottom corner. The apparatus is supported via two (2) wheel assemblies each supported by separate axles. To use the apparatus, a door is placed with its forward corner in the apparatus. The rear portion of the door is then lifted and balanced by the user while being pushed where the door is needed. The low profile design of the apparatus allows the load to be transported through narrow hallways or doorways.

Description:
RELATED APPLICATIONS 
     The present invention was first described in a notarized Official Record of Invention on Jul. 22, 2009, that is on file at the offices of Montgomery Patent and Design, LLC, the entire disclosures of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates generally to dollies, and in particular, to a device specially adapted to help a single user transport large, flat materials such as drywall, doors, and the like. 
     BACKGROUND OF THE INVENTION 
     Movement of tools and materials around a construction site or similar project site often represents a substantial portion of the time and effort required to complete a project. While some smaller and lighter objects can be transported by hand, objects of difficult shape and weight require multiple persons or special tools or equipment for transportation. 
     In particular, objects such doors and sheet materials are difficult to transport due to the fact that they are large in at least one (1) dimension. This can result in frustration and wasted labor costs since the moving of such objects requires a level of coordination, navigation, and effort disproportionate to the weight of the objects. In addition, many common transportational tools such as dollies and the like are not well suited to moving objects with such dimensions. This can cause undue difficulty in maneuvering such objects in narrow hallways, for example. 
     Various attempts have been made to provide dolly devices for doors and similarly dimensioned materials. Examples of these attempts can be seen by reference to several U.S. Pat. No. 3,841,651, issued in the name of Bigney, describes a hand truck adapted to receive sheet materials with a locking bar for retaining the materials during transport. 
     U.S. Pat. No. 5,284,410, issued in the name of Sare et al., describes a sheet material carrying device comprising a “U”-shaped frame which receives an edge of a sheet material. The Sare device provides wheels to allow a user to push the sheet material along a ground surface. 
     U.S. Pat. No. 5,288,090, issued in the name of Bross, describes a door dolly which provides engagement for a lower corner of a door or similarly shaped object while providing a handled rolling means to a single user for transport of the object. 
     U.S. Pat. No. 6,264,184, issued in the name of Armstrong et al., describes a wheeled door carrier with a vice mechanism which aids a single user in the transport and hanging of a door or similar panel object. 
     U.S. Pat. No. 6,866,274, issued in the name of Muscat, describes an article transport dolly for sheet materials which provides a wheeling means including a non-slip surface and braking features. 
     Additionally, ornamental designs for a door or sheet material dolly exist, particularly U.S. Pat. Nos. D 310,894; D 340,337; and D 550,921. However, none of these designs are similar to the present invention. 
     While these devices fulfill their respective, particular objectives, each of these references suffer from one (1) or more of the aforementioned disadvantages. Many such devices are themselves bulky, making for difficult in storing and transporting the device during periods of non-use. Also, many such devices do not adequately secure the transported materials which can cause dislodging when experiencing bumps or the like. Furthermore, many such devices only allow transport of the materials in one particular spatial orientation which can make fitting and maneuvering the carried objects difficult in narrow spaces. In addition, many such devices are not easily resizable and adjustable to secure accommodate varying thicknesses or amounts of doors or sheet materials. Accordingly, there exists a need for a door and sheet material transporter without the disadvantages as described above. The development of the present invention substantially departs from the conventional solutions and in doing so fulfills this need. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing references, the inventor recognized the aforementioned inherent problems and observed that there is a need for a means to provide a compact, simple device which aids a single user in the transport of large, flat objects such as doors and sheet materials in a manner which is quick, adjustable, and readily maneuverable. Thus, the object of the present invention is to solve the aforementioned disadvantages and provide for this need. 
     To achieve the above objectives, it is an object of the present invention to aid in moving and transporting heavy flat objects such as doors and large sheet materials. The apparatus comprises a pair of “L”-shaped brackets each with an independent wheel portion. The two (2) halves are attached via a folding hinge. 
     Another object of the present invention is to provide secure gripping to an object placed in the apparatus. The weight of the object collapses the hinge inwardly to provide a clamping gripping means to a contained object. 
     Yet still another object of the present invention is to allow for maneuvering through narrow hallways or similarly obstructive passages. The apparatus retains a front corner of a door or similar object such that a user lifts and pushes from a rear corner of the object, allowing the user to pivot the object in an up and down manner to navigate a path. 
     Yet still another object of the present invention is to allow easy insertion of an object into the apparatus bracket in a manner which does not damage the object. The wall portions of each bracket assembly comprise a curved profile which provides a secure clamping function with a curved top edge to prevent scratching and the like during insertion. 
     Yet still another object of the present invention is to provide strength to the retaining bracket assemblies via a plurality of integrally molded linear stiffeners located within wall and base plate portions of each bracket assembly. 
     Yet still another object of the present invention is to allow the bracket assemblies to pivot both toward and away from each other in order to selectively accommodate objects of varying thickness. Each bracket assembly is connected to an independent wheel axle and wheel in order to allow separate motioning of each side of the apparatus. The apparatus can accommodate large loads via outward motioning of the brackets while still maintaining a clamping force on the load. 
     Yet still another object of the present invention is to comprise a small semi-circular handle which allows a user to easily carry the apparatus when not loaded. 
     Yet still another object of the present invention is to provide a method of utilizing the device that provides a unique means of obtaining the apparatus, transporting it to a desired location for use via the carrying handle, opening the brackets to a desired width, loading the apparatus with a front corner portion of a door, sheet material, or similarly large, flat object or plurality of objects, automatically securing and clamping the objects via their weight and the inward collapsing motion of the hinge, manually lifting a rear corner of the loaded object or objects, pushing the objects along a ground surface and maneuvering manually around narrow passages and the like, unloading the objects upon reaching a desired destination, and transporting the apparatus via the handle and subsequently storing the apparatus during periods of non-use. 
     Further objects and advantages of the present invention will become apparent from a consideration of the drawings and ensuing description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is a front perspective environmental view of a material transporter  10  depicting an in-use state, according to a preferred embodiment of the present invention; 
         FIG. 2   a  is a close-up front view of the material transporter  10 , according to a preferred embodiment of the present invention; 
         FIG. 2   b  is a close-up rear view of the material transporter  10 , according to a preferred embodiment of the present invention; 
         FIG. 3  is an exploded view of the material transporter  10 , according to a preferred embodiment of the present invention; and, 
         FIG. 4  is a front perspective view of the material transporter  10  depicting transportation of multiple sheets of plywood  110 , according to a preferred embodiment of the present invention. 
       DESCRIPTIVE KEY 
       
           
           
             
                 10  material transporter 
                 20  first retaining bracket assembly 
                 22  first wall 
                 24  first base plate 
                 26  first stiffener feature 
                 28  hinge element 
                 29  hinge pin 
                 30  second retaining bracket assembly 
                 32  second wall 
                 34  second base plate 
                 36  second stiffener feature 
                 40  wheel 
                 42  axle 
                 44  retaining washer 
                 46  cotter pin 
                 48  hub feature 
                 50  first front plate 
                 52  fastener aperture 
                 55  second front plate 
                 60  handle 
                 80  fastener 
                 100  door 
                 110  sheet material 
                 120  ground surface 
             
           
         
      
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within  FIGS. 1 through 4 . However, the invention is not limited to the described embodiment and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
     The present invention describes a device and method for a material transporter (herein described as the “apparatus”)  10 , which aids in moving and transporting heavy flat objects such as doors  100 , large sheet-type materials  110 , or the like. The apparatus  10  comprises a pair of “L”-shaped brackets attached to each other via a folding hinge  28 . The hinge  28  allows a weight of the carried materials  100 ,  110  to collapse the hinge  28  inwardly thus securely gripping the door  100  or sheet material  110 . The apparatus  10  also comprises a pair of front plates  50 ,  55 , thereby forming a four-sided captivating structure around a front corner area of the door  100  or sheet material  110 . The apparatus  10  transports the door  100  or sheet material  110  using two (2) strong supporting wheel portions  40 , each having an independent axle  42 . 
     Referring now to  FIG. 1 , a front perspective view of the apparatus  10  depicting an in-use state, according to a preferred embodiment of the present invention, is disclosed. The apparatus  10  comprises a first retaining bracket assembly  20 , a second retaining bracket assembly  30 , a first front plate  50 , a second front plate  55 , and a pair of wheels  40 . The retaining bracket assemblies  20 ,  30  and the attached front plates  50 ,  55  form a four-sided enclosing structure to securely position a front lower corner of a vertically orientated door  100  or piece of sheet material  110 . In use, the front corner of the door  100  or sheet material  110  is placed into the apparatus  10  while a user lifts and pushes a rear corner portion of said door  100  or sheet material  110  along a ground surface  120 , thereby providing easy passage through narrow hallways or doorways. 
     Referring now to  FIGS. 2   a ,  2   b , and  3 , front, rear, and exploded views of the apparatus  10 , according to a preferred embodiment of the present invention, are disclosed. The apparatus  10  provides a collapsing structure to secure a front bottom corner of a door  100  or piece of sheet material  110  within. 
     The apparatus  10  comprises a one-piece first retaining bracket assembly  20  further comprising a first wall  22 , a first base plate  24 , and three (3) first stiffeners  26 . Said first wall  22 , first base plate  24 , and first stiffeners  26  comprise a single rigid plastic part being manufactured in a molding or extruding process; however, said portions  22 ,  24 ,  26  may also be made using a rugged metal material being welded together with equal benefit and as such should not be interpreted as a limiting factor of the apparatus  10 . The wall portion  22  extends upwardly from the horizontal first base plate portion  24  at an angle of approximately ten degrees (10°) from a vertical plane. Said wall portion  22  leans inwardly toward a center portion of the apparatus  10  and gently curves outwardly along a top edge, thereby allowing easy entry of said door  100  or piece of sheet material  110  without scratching. 
     The apparatus  10  further comprises a second retaining bracket assembly  30  comprising a second wall  32 , a second base plate  34 , and three (3) second stiffeners  36 . The second retaining bracket assembly  30  comprises a minor image of the previously described first retaining bracket assembly  20 , incorporating similar materials and functions as described. The first  20  and second  30  retaining bracket assemblies are affixed thereto each other and able to pivot towards each other via an axial hinge device  28  located along an adjacent inward edge of the first  24  and second  34  base plates and extending between said assemblies  20 ,  30  in a linear fashion. The hinge  28  is secured by inserting a round hinge pin  29  through a central opening in a conventional manner. The inwardly pivoting motion of the first  22  and second  32  wall portions provide a clamping means thereto the included door  100  or piece of sheet material  110  as the weight of said door  100  or sheet material  110  is applied downwardly upon the first  24  and second  34  base plate portions, causing the first  22  and second  32  wall portions to correspondingly rotate inwardly. 
     The first  20  and second  30  retaining bracket assemblies are further strengthened by a plurality of integrally-molded first  26  and second  36  stiffeners. Said stiffeners  26 ,  36  are molded into respective first  22  and second  22  wall portions and first  24  and second  34  base plate portions and horizontally disposed in a parallel manner to said base plate portions  24 ,  34 . Said stiffeners  26 ,  36  comprise linear tubular elements providing hollow centers to receive a fastener  80  into such as a self-tapping screw. Said stiffeners  26 ,  36  provide an attachment means thereto the first  50  and second  55  front plates comprising integral fastener aperture portions  52  being correspondingly positioned relative to said stiffeners  26 ,  36 . Said first  50  and second  55  front plates are fastened to the stiffener portions  26 ,  36  of the respective first  20  and second  30  retaining bracket assemblies along forward edge regions using common fasteners  80  such as screws. The front plates  50 ,  55  also act as a forward stopping surface to position the transported door  100  or sheet material  110 . Said first  50  and second  55  front plates comprise adjacent contacting edges designed to protrude and interlock with each other to distribute a load from the door  100  or sheet material  110  equally upon both front plates  50 ,  55 . The front plates  50 ,  55  are envisioned to be made of similar materials as the retaining bracket assemblies  20 ,  30 . 
     Each retaining bracket assembly  20 ,  30  comprises an integral axle hub feature  48  along a respective bottom outer edge. Each hub feature  48  comprises a circular orifice approximately one (1) inch long being suitably sized to receive an axle portion  42  of a respective wheel  40  therethrough. Each assembly of the wheel  40 , wheel axle  42 , and the hub feature  48  provides an independent and rotating support to the respective retaining bracket assembly  20 ,  30 , thereby allowing said retaining bracket assemblies  20 ,  30  to pivot freely toward or apart from each other based upon a thickness of the door  100  or the sheet material  110  being transported. The wheels  40  comprise heavy-duty plastic or metal rolling members being approximately six (6) inches in diameter and having integrally-molded axle portions  42 . Said wheels  40  are envisioned to provide molded or bonded tread surfaces around a perimeter surface to improve traction across a ground surface  120 . Furthermore, said wheels  40  and axles  42  are envisioned to be retained in the respective hub features  48  using a retaining washer and a cotter pin  46  or equivalent retention method. 
     The apparatus  10  also comprises a flexible semi-circular plastic or rubber handle  60  having end portions which enable mounting of said handle  60  to adjacent rear edges of the first  24  and second  34  base plates using common fasteners  80 . Said handle  60  allows a user to easily carry the apparatus  10  in an unloaded state as needed. 
     Referring now to  FIG. 4 , a front perspective view of the apparatus  10  depicting transportation of multiple sheets of plywood  110 , according to a preferred embodiment of the present invention, is disclosed. The independent attachment of the wheels  40  to the respective retaining bracket assemblies  20 ,  30 , and the angular motioning of the center hinge  28  allows the wall portions  22 ,  32  of the retaining bracket assemblies  20 ,  30  to pivot freely toward or apart from each other. Said motioning of the wall portions  22 ,  32  enables a user to load the apparatus  10  with multiple items, or extra-thick items, resulting in a varying total thickness of a load, while still maintaining a clamping force from the wall portions  22 ,  32  to said items  100 ,  110 . In this manner, the apparatus  10  may transport several pieces of sheet material  110  as seen here. Furthermore, the interlocking and overlapping features of the front plates  50 ,  55  provide continuous support to the door  100  or sheet material  110  while the apparatus  10  is in a maximum or spread-apart state. 
     It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After initial purchase or acquisition of the apparatus  10 , it would be utilized as indicated in  FIGS. 1 and 4 . 
     The method of assembling and utilizing the apparatus  10  may be achieved by performing the following steps: assembling the two (2) wheels  40  thereto the first  20  and second  30  retaining bracket assemblies, if not previously installed, by inserting the respective axle portions  42  through the hub features  48 ; retaining said wheels  40  by installing the retaining washers  44  and cotter pins  46  thereto said axle portions  42 ; joining the first  20  and second  30  retaining bracket assemblies together by inserting the hinge pin  29  thereinto the integral hinge  28 , if not previously installed; mounting the first  50  and second  55  front plates thereto the respective first  20  and second  30  retaining bracket assemblies using the fasteners  80 ; loading the apparatus  10  with a door  100  or a piece of sheet material  110  by positioning a forward bottom corner of the vertically orientated door  100  or sheet material  110  between the first  22  and second  32  wall portions being positioned against the front plates  50 ,  55 ; manually lifting a rear corner of the loaded door  100  or sheet material  110  thereto a comfortable height off a ground surface  120 ; pushing forwardly against the door  100  or sheet material  110 , thereby propelling the loaded apparatus  10  along said ground surface  120  and/or through narrow halls and doorways as needed; unloading the door  100  or sheet material  110  in a normal manner upon reaching a destination; carrying the empty apparatus  10  when not in use using the handle  60 ; and, benefiting from reduced effort and awkwardness associated with moving doors  100  and sheet materials  110  afforded a user of the present apparatus  10 . 
     The apparatus  10  may be utilized to transport a plurality of pieces of sheet material  110  in like manner by allowing the first  22  and second  32  wall portions to separate a necessary distance as required to contain a desired quantity of sheet material  110 ; positioning forward bottom corners of said sheet material  110  between the first  22  and second  32  wall portions being positioned against the front plates  50 ,  55 ; manually lifting rear corner portions of said sheet material  110 ; and, transporting said sheet material  110  across a ground surface  120  as previously described. 
     The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.