Abstract:
A door frame with a substantially continuous sealing surface supports a door with a substantially continuous sealing member mounted thereon. A stepped U-shaped frame member has an opening at one end that is closed with a square-cut member, such as a threshold. The frame, threshold and hinges mounted on the frame provide a substantially continuous sealing surface. The bores of the hinge knuckles may be matched with bushings in the bores, so that the bushings must be properly oriented. The heads of the bushings may have at least two steps or raised contact surfaces and at least two indentations or depressed contact surfaces. When the doors are opened, the steps on their bushings in the pivoting hinge leaves drop into the indentations in the adjacent fixed hinge leaf and hold the door in position.

Description:
TECHNICAL FIELD 
   This invention relates to doors. More particularly, it relates to combination doors, for vehicles such as motorized recreational vehicles, utility trailers and the like, that are designed for trouble free and comfortable service, and for economical, efficient and flexible production. 
   SUMMARY OF THE INVENTIONS 
   This invention provides a door assembly with a frame assembly having a substantially continuous sealing surface around the entire periphery of the frame assembly. A first door, such as a prime door, has a substantially continuous sealing member mounted thereon. The sealing surface and sealing member provide a substantially continuous seal around the door when it is closed. Preferably, a second substantially continuous seal on a second door, such as a screen door, seals against insects. The weather seal on the prime door and the insect seal on the screen door are mechanically fastened or otherwise attached to the main frame of the door for consistent performance and aesthetics. 
   In one embodiment, a stepped U-shaped frame member has an opening at one end that is closed with a square-cut member, such as a threshold, leaving gaps at the outer steps of the frame. Plugs fill these gaps, providing a continuous surface without expensive machining of the threshold. The frame and doors shown herein have curved upper corners, but it should be understood that the term “U-shaped” includes other shapes with three closed sides and one open side, such as a rectangular door frame with a straight top and sides. 
   Continuous sealing surfaces may be formed with interfitting frames and hinges. The preferred frame has a rib with an outwardly facing surface that forms much of the sealing surface. The rib is notched to accept the fixed hinge leaf of a hinge assembly. The fixed hinge leaf is stepped to fit into a notch in the frame rib, and to provide a surface that is substantially coplanar with the outwardly facing surface of the rib. In turn, the fixed hinge leaf is notched to accept at least one pivoting hinge leaf, which is also stepped to provide a surface that is coplanar with the above-identified surfaces of the fixed hinge leaf and the frame rib. The end result is a substantially coplanar, outwardly facing sealing surface that extends through the hinge area, eliminating the need for multiple, specially constructed seal parts, which improves seal integrity. 
   Inter-fitting frames and hinge parts can also simplify manufacture, strengthen the completed assembly and help meet Federal motor vehicle safety standards, such as Federal Standard FMVSS 206. For example, the main frame assembly for a door may have a groove with an undercut or dovetail surface, and parts of a hinge assembly attached to this frame may have a rib with an outwardly sloping surface that complements and interlocks with the dovetail groove in the frame. Another interlocking system has a component, such as a door surround, with kerfs to support a sealing member and notches for other components, such as hinge leafs, which also have kerfs for the sealing member. The surround has a rib that fits into a grove on the hinge leaf, which ensures precise alignment of the kerfs, facilitates installation of the sealing member and increases structural integrity. 
   The preferred door assembly has at least one hinge assembly with a mounting plate having an upper fixed knuckle, a lower fixed knuckle and, optionally, one or more intermediate fixed knuckles. Stepped bushings, with bodies that complement the bores of the knuckles, and larger heads that ride on the rims of the knuckles, are inserted into the top end of the fixed hinge bushings, and into the bottom end of the knuckle or knuckles of one or more pivoting hinge leafs that fit between and are coaxial with the fixed hinge knuckles. As a result, the bushings in the pivoting leafs, which support the door or doors, bear on bushings in fixed knuckles. The hinge pin extends through these bushings and, optionally, through cylindrical plugs that limit the required length of the bushings and ease molding requirements. The moveable hinge leaf can pivot with respect to the fixed hinge leaf without metal-to-metal contact between the knuckles, and between the pin and the knuckles. Metal-to-metal wear is eliminated, which also reduces attendant discoloration. 
   The bores and bushings are preferably designed, e.g. with matching grooves and ribs, so that the bushings must be properly oriented to fit into the bores. In one embodiment, the heads of the bushings have at least two steps or raised contact surfaces and at least two indentations or depressed contact surfaces. When the doors are opened, the steps on their bushings in the pivoting hinge leaves drop into the indentations in the adjacent fixed hinge leaf and hold the door in position. 
   Other features and advantages of this invention will be apparent from the following detailed description. 

   
     DRAWINGS 
       FIG. 1  is an isometric view of a door assembly embodying this invention. 
       FIG. 2  is a vertical cross section through the prime door shown in FIG.  1 . 
       FIG. 3  is a horizontal cross section through the same prime door. 
       FIG. 4  is an enlarged fragmentary cross section of the door in  FIG. 3 , with the mainframe and screen door leaf pivoted 90° and 45° respectively for ease of understanding. 
       FIG. 5  provides detail views of the weather seal and an optional noise reduction seal. 
       FIG. 6  is a fragmentary, exploded, isometric view of the main door frame member, threshold and hinge assembly for the door illustrated in the previous figures. 
       FIG. 7  is a side elevation view of a hinge assembly with fragments of the main frame assembly on which it is mounted. 
       FIGS. 8A and 8B  are expanded, fragmentary cross sectional views along lines A—A and B—B respectively in FIG.  7 . 
       FIGS. 9A ,  9 B and  9 C are isometric views of two bushings that may be used in hinges for doors embodying this invention. 
       FIG. 10  is a further enlarged, fragmentary crosssectional through the screen hinge leaf, fixed hinge leaf and main frame member of the assembly shown in the forgoing figures. 
   

   DETAILED DESCRIPTION 
   The door assembly illustrated in  FIG. 1 , generally referred to as  10 , includes: a frame assembly  20 , a prime door  40 , and a screen door  60 . Frame assembly  20  has a U-shaped main frame member  21  with an open lower end  211 , which is closed by an extruded aluminum threshold  23 , attached to the main frame member by screws (not shown) that extend through the frame member into semicircular screw bosses  233  shown in FIG.  2 . Threshold  23  rests on the body of the vehicle V in which the door assembly is installed. As shown in  FIGS. 2 and 3 , the main frame member is fastened to the vehicle by screws (not shown) extending through a mounting flange  213  and a layer of butyl tape  33 , which seals any gaps between the main frame member and the side of the vehicle. A screw cover  31 , which snaps into mounting flange  213 , covers these screws. A laterally extending flange  29  on the main frame, and a trim ring  39 , attached to the inner wall of the vehicle, close any gaps between the inside wall and the frame. A sill filler strip  27 , attached to the vehicle by screws (not shown) extending through the filler strip and through a layer of butyl tape  33 , closes any gap between the lower edge of the threshold and the vehicle. 
   The doors are attached to the frame by three hinge assemblies  80 , shown in  FIGS. 3 ,  4 , and  6 - 10 . Each hinge assembly consists of a fixed leaf  81  bolted to the main frame  21 , a prime leaf  83  which supports the prime door  40 , a screen leaf  85  which supports the screen door  60 , and associated hardware described below.  FIG. 3  provides a horizontal cross-sectional view of a hinge, with the doors in the closed position. The enlarged fragmentary cross-sectional view in  FIG. 4  shows the frame  21  and screen door  60  rotated clockwise 90° and 45°, respectively, for ease of understanding. 
   The prime door  40  has a core  41  of an expanded material such as polystyrene, a smooth skin  43  of a material such as fiberglass or aluminum on the outside of the core, and a similar smooth skin  45  on the inside of the core. A generally U-shaped steel stile  47  protects the edges of the foam core, and provides substantial strength and rigidity. The inner and outer skins  43 ,  45 , are laminated to the core  41  and to the stile  47 . As also shown in  FIGS. 2-4 , an extruded aluminum door surround  49  encloses and reinforces the outer and inner door skins  43 ,  45  and the stile  47 . Surround  49  has a seal flange  491  which, in connection with hinge assemblies  80 , supports a substantially continuous weather seal assembly  55 , as explained below. An unbroken U shaped weather seal member  555 , mounted in cruciform-shaped kerfs  493  in the door surround seal flange  491 , and in kerfs  835  in the prime hinge leafs  83 , as shown in  FIGS. 8A ,  8 B and  10 , provides an unbroken U-shaped weather seal around the sides and top of the prime door  40 . Weather seal member  555 , in conjunction with a lower seal member  553  mounted in the door surround seal flange  491  at the bottom of the prime door, forms a substantially continuous unbroken weather seal  55  around the prime door. 
   The kerf  835  in the prim hinge leaf  83  supports weather seal member  555 , as shown in  FIGS. 7 and 8B , across the notch  816  (in the fixed hinge leaf  81 ) or the prime hinge leaf. The kerf  493  in surround seal flange  491  supports the weather seal  555  around the rest of the main frame, as shown in  FIGS. 8A and 10 , and supports the weather seal assembly  553  across the bottom of the door. Kerfs  493  and  835  are aligned. Thus, they provide continuous support for the unbroken weather member  555 , and eliminate any requirement for short seal pieces in the hinge area. 
   As shown in  FIG. 5 , weather seal members  555  and  553  have two parts: a relatively rigid spine  551  which is inserted into kerfs  493  and  835 , and a more flexible serpentine member  557 . The spine is preferably made of a relatively rigid material such as polypropylene, and the serpentine member is preferably made of a more flexible material such as SANTOPRENE® Shore 65A Flexible, which are made by Monsanto. These materials can be co-extruded to make a single integrated strip. 
   A noise reduction seal  57  may optionally be used with weather seal member  555 . As shown in  FIG. 5 and 10 , noise reduction seal  57  is L-shaped. The shorter leg fits into the outer curve of the seal member  555 . Adhesive secures the other leg to the outside of the door surround seal flange  491 . When used, the noise reduction seal preferably extends from the threshold to the top of the straight portion of the hinge side of the prime door. The noise reduction seal may be an extruded foam. 
   When the prime door is closed, weather seal  55  presses against a substantially continuous and coplanar sealing surface formed by main frame member  21 , threshold  23 , and the hinge assemblies  80 . As best seen in  FIGS. 6 and 10 , the main frame member  21  has an outwardly extending rib  35  with an outwardly facing surface  215  which is one of the main parts of this continuous sealing surface. The threshold  23  has a similar outwardly facing surface  235 . As may be seen in  FIG. 2 , surfaces  215  and  235  are substantially coplanar, and are substantially parallel to the outer and inner skins  43 ,  45  of the door when the door is closed. 
   As also best seen in  FIG. 6 , the rib  35  on the main fame has notches  37  for the hinge assemblies  80 . Similarly, the fixed leaf  81  of each hinge assembly has notches  813  for the screen door leaf. The outwardly facing, unnotched sections  215  of the main same seal rib  217 , the outwardly facing, unnotched sections of the fixed hinge leaves and the outwardly facing sections  853  in the screen hinge leaves  85  are substantially coplanar and provide a continuous outwardly facing sealing surface across the hinges. Thus, an unbroken seal can be provided across the hinges with a single unbroken weather sealing member  555 , which contributes significantly to performance, dependability and manufacturing economy. 
   Referring to  FIGS. 6 and 10 , there are two small ribs  821  on the back side of the rearwardly extending or laterally facing step  823  in the fixed hinge leaf  81 . They minimize the risk that flash or scrap from the cutting of the notches  813  in the fixed hinge leaf will keep the hinge assemblies from being positioned properly in the main frame notches  219 . 
   The main frame member, hinge assemblies and prime door are also designed for ease of assembly and structural integrity. As best seen in  FIG. 4 , the main frame assembly has a groove  221   20  with an inwardly sloping or dove-tailed side  223 . The fixed hinge leaf and screen hinge leaf have ribs ( 815  and  855  respectively) with complimentary front edges  817 ,  857  that fit into and interlock with the sloping side  223  of groove  221 . This facilitates alignment of the hinge assembly during assembly, and provides additional strength. 
   In addition to providing a continuous mount for weather seal member  555 , as described above, prime hinge leaf  83  and door surround  49  contribute to ease of assembly, structural integrity, and effective sealing. As may be seen in  FIGS. 8A and 8B , a rib on the door surround seal flange  491  extends into a mating groove  837  on the prime hinge leaf  83 . This ensures perfect alignment of the kerf  493  in the surround and the kerf  835  in the prime hinge leaf, and also contributes to structural rigidity. The prime hinge leaf also has a rib  839 , on the opposite side of the leaf from groove  837 . As seen in  FIG. 10 , this closes the gap created by the notch  815  for the prime hinge knuckle  831  when the prime door is closed. 
   The weather seal provided by seal assembly  55  is supplemented by a screen door seal assembly  61 , shown in  FIG. 2 , consisting of a U-shaped strip  611  of pile, preferably polypropylene, mounted in a screen door seal flange  221  at the inner end of mainframe member, and a similar strip  613 , mounted in the bottom of the screen door. 
   As best seen in  FIG. 6 , the filler plug  24  has a rib  241  which fits into the groove  222  in the main frame member, and 2 prongs  243  which are inserted into spaces in the outer (and lowest) section of threshold  23 . 
   As best seen in  FIG. 7 , the fixed hinge leaf has three knuckles  811  for a hinge pin  91 . These knuckles are separated by two notches: a smaller notch  814  for the prime hinge leaf  83  and a larger notch  815  for the screen hinge leaf  85 . The prime hinge leaf and screen hinge leaf have similar knuckles ( 831  and  851  respectively), partially cut away to accommodate acetal plastic hinge bushings  87 , which are inserted into the top of the bores  825  in the fixed hinge leaf knuckles  811  and the bottom of the bores  845 ,  856  in the prime hinge leaf knuckle  831  and screen hinge leaf bushing  851 . Hinge pin  91  extends through the bushings, through plugs  89  in each knuckle, one of which is illustrated in the cut-away portion of the screen leaf bushing in  FIG. 7 , and through a washer  93  beneath the lowest fixed hinged bushing. The lower end  91  of the hinge pin is swedged to provide a secure assembly. With the positive location afforded by the notches in the weather seal rib  217 , the hinge assemblies lend themselves to removal of an entire door and/or replacement of an individual hinge, if damaged through negligence. 
   The bushings in hinge knuckles  811 ,  831  and  851  may be designed to hold one or both doors in a certain open position.  FIGS. 9A and 9B  illustrate two types of bushings  86 ,  88 . The bodies  861 ,  881  of both bushings, i.e. the smaller parts of the bushings that are inserted into the bores in the hinge knuckle, have a number of relatively narrow, “V” shaped ribs  871 ,  891  designed to fit into complimentary V shaped grooves in the bores of the hinge knuckles  811 ,  831  and  851 , best seen in  FIG. 10 , and one or more wider ribs designed to fit into wider grooves  823  in the bores of the knuckles. As best seen in  FIG. 10 , the illustrated bores and bushings have two wider grooves or ribs, on opposite sides of the bore or bushing. Thus, the illustrated bushings can be inserted into the illustrated bushings in two positions, 180° apart. 
   Bushing  86  has a head  875  with a flat contact surface  876  that does not influence the position of either door, but indexing bushing  88  is designed to hold either door in place when it is opened 90°. The head  885  of the indexing bushing  88  has two steps  886  on opposite sides of head  875 , and two indentation is  887  separating the steps. Inclined surfaces  888  connect the steps and indentations. Each of the steps and indentations surfaces spans an arc of approximately 30° 
   With these indexing bushings, the steps  886  of the bushings in the prime hinge knuckle  831  and the screen hinge knuckle  851  rest on the steps  886  of bushings in fixed hinge knuckles  811  when the doors are closed. However, when a door is opened 90°, the steps of the bushings in the pivoting leaves will rest in the indentations of bushings in fixed hinge knuckles  811 , and the door will remain in this position until it is closed, manually, or opened further. The doors described above are considerably thicker than conventional doors. This provides extra stiffness and allows the doors to be manufactured as a flat assembly, unlike conventional doors that bowed to provide compression against seals to provide additional compression against seals and reduce door vibration and “flutter” in motion. The ability of the doors to seal as a flat rather than a concave assembly reduces closing force and adds to the perceived quality of the door during operation. As those skilled in the art will recognize, the structures described above, shown in the accompanying drawings and defined by the following claims offer substantial advantages over door assemblies previously available for recreational vehicles, including a substantially continuous sealing surface around the entire periphery of the main door frame, which in turn makes it feasible to use a substantially continuous weather seal around substantially the entire periphery of the door, including the area where the hinges are mounted. The substantially continuous sealing surface is formed, in part, with an interfitting frame and hinges. The hinges are also mechanically locked into the frame, which increases structural integrity and eases assembly. Knuckles of the pivoting leaves of the hinges are spaced from the fixed leaf knuckles by bushings, and further separated from the hinge pin by plugs. The bushings and plugs eliminate metal-to metal wear. The bushings may also serve as indexing function, holding the doors in position when open. 
   Of course, those skilled in the art will readily appreciate that many modifications may be made in the structure disclosed above. The foregoing description is merely illustrative, and is not meant to limit the scope of this invention, which is defined by the following claims.