Patent Publication Number: US-6659155-B1

Title: Bidirectional swinging screen door and frame assembly

Description:
FIELD OF THE INVENTION 
     The present invention relates to doors for patio doorways and particularly pertains to a bidirectional swinging screen door and frame assembly. 
     BACKGROUND OF THE INVENTION 
     Patio doorways are often configured with a sliding glass door arrangement. Such doorways are typically framed with tracks for sliding one or more doors open and closed. Within this patio doorway frame a seasonal sliding screen door can be arranged parallel to the sliding glass door. By sliding the glass door along the track to its open position and having it remain in the open position, the screen door can then function as the primary means for exiting and entering through the patio doorway. The sliding screen door maintains a barrier between the outdoors and inside of the home while providing for increased fresh air and sensory perception of the recreation in the backyard or patio. 
     Improvements in screen door arrangements provide a more versatile and aesthetically pleasing entryway. Many of these improvements are described in U.S. Pat. No. 4,838,332 to Mlenek. The assembly includes a replacement screen door surrounded by a frame which connects to the patio doorway of the house. Once mounted to the patio doorway of the house, the screen door is hinged within the frame, allowing the door to be opened in either an inwardly or outwardly direction. In addition, the assembly has a mechanism for returning the door to the closed position. 
     While this prior art assembly is generally effective, it lacks many desirable functional attributes. First, the frame of the assembly only borders three sides of the opening, making alignment of the two screen doors difficult. Second, the doors lack the ability to be detained in the open position. Third, the doors lack the ability to be elevated when opened to clear rugs or other structures on the floor adjacent the doors. Still other aspects of this prior art assembly make it less than optimal and amenable to improvement. 
     SUMMARY OF THE INVENTION 
     The present invention provides a bidirectional swinging door assembly for mounting in a patio doorway. The assembly of this invention includes a frame attachable to the patio doorway and at least one door, such as a screen door, pivotably mounted to the frame. 
     The frame is configured so that it entirely surrounds an opening in the patio doorway. Preferably, two doors are pivotably attached to the frame in a manner allowing each door to swing both inward and outward relative to the doorway. A user can thus easily pass through the doorway in either direction by merely pushing the doors in a swinging fashion from a closed position occluding the opening to an open position allowing the user to pass through. 
     At least one hinge supports each door in a pivoting fashion relative to the frame. The hinge is configured to allow each door to swing both inward and outward. Each door includes a means to bias the door toward a closed position. Preferably, this biasing means is in the form of a sloped ramp coupled to the frame beneath the door and a wing on the door located such that the wing rides up the slope when the door is moved from the closed position to the open position. Gravitational forces thus bias the door towards the closed position. Preferably, a means is provided to detain the door in an at least partially open position so that the door can remain open when in this detained position. Preferably, this detaining means is in the form of a notch in the wing and a crest at a top of the slope so that when the notch in the wing aligns with the crest of the slope, the door is held stationary in this at least partially open position. 
     Preferably, the hinge includes an upper portion and a lower portion each coaxially aligned with a common pivoting axis. The upper portion of the hinge pivotably couples a top portion of the door to a top portion of the frame. A lower portion of the hinge couples a lower portion of the door to a lower portion of the frame. 
     In addition to the slope and wing or other means to bias the door toward the closed position, the slope and wing configuration additionally provides a preferred form of a means to elevate the door when the door is opened away from the closed position. As the wing rides up the slope, the door is elevated, allowing a lower portion of the door to more easily clear obstacles resting upon the ground adjacent the doorway and inside or outside of the structure in which the doorway is located. 
     OBJECTS OF THE INVENTION 
     Accordingly, a primary object of the present invention is to provide a screen door that opens in either direction; i.e., the screen door swings inwards as well as outwards. 
     Another object of the present invention is to provide a bidirectional swinging screen door with a door stop for detaining the door in open positions. 
     Another object of the invention is to provide a screen door in which a person may choose between pushing or pulling the door open when both entering and exiting through the doorway. 
     Another object of the invention is to provide a bidirectional swinging screen door that opens without excessive force allowing a person to pass through whose hands are not free or who may be using a wheelchair or other means of mobility that require the use of the hands. 
     Another object of the invention is to provide a bidirectional swinging screen door that is both lightweight and sturdy. 
     Another object of the invention is to provide a bidirectional swinging screen door that, when opening in either direction, elevates above the threshold to achieve suitable clearance of carpet, rugs, mats, or other common structures within the entryway. 
     Another object of the invention is to provide a screen door which returns to the closed position after it has been opened in either direction. 
     Another object of the invention is to provide a screen door that maintains a weatherproof seal. 
     Another object of the invention is to provide a screen door frame assembly which may be adjusted to fit in commercially available patio doorways. 
     Another object of the invention is to provide a screen door which can be easily installed adjacent a doorway opening with the doors having precise proper alignment. 
    
    
     Other further objects of the present invention will become apparent from a careful reading of the included drawing figures, the claims and detailed description. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the screen door assembly of the present invention installed in a patio doorway. The embodiment shown comprises a screen door having two separately hinged screen panels in which one panel may be opened mutually exclusive of the other. 
     FIG. 2 is a perspective view of the installed screen door having the two screen panels detained in diametrically opposed open positions. 
     FIG. 3 is a perspective view of the lower corner of the screen door and frame in the closed position, showing the bottom portion of the two-point connection hinge and knuckle joint. 
     FIG. 4 is a perspective view of the same lower corner of the door and frame shown in FIG. 3 with the knuckle joint shown with the door in a partially open position. 
     FIG. 5 is a perspective view of the same lower corner of the door and frame shown in FIGS. 3 and 4 with the knuckle joint in operation as the door is detained in the open position. 
     FIG. 6 is a perspective view of the bottom portion of the two-point connection hinge or knuckle joint appears unmounted in the door and frame. 
     FIG. 7 is a perspective view of the same knuckle joint shown in FIG. 6 as it would appear in operation with the door in a partially open position. 
     FIG. 8 is a perspective view of the same knuckle joint shown in FIGS. 6 and 7 as it would appear with the door detained in the open position. 
     FIG. 9 is a full-sectional view of the knuckle joint taken along line  9 — 9  of FIG. 3, showing the knuckle joint with the door in the closed position. 
     FIG. 10 is a full-sectional view taken along line  10 — 10  of FIG. 5, showing the knuckle joint with door detained in the open position. 
     FIG. 11 is a full-sectional view of the top portion of the two-point connection hinge and recoil joint. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral  10  is directed to a bidirectional swinging screen door assembly for a patio doorway  12 . The door assembly  10  is configured to be installed adjacent the doorway  12  so that the doors  30  can pivot both in and out through an opening  14  in the doorway  12 . 
     In essence, and with particular reference to FIGS. 1-5, the basic details of the screen door assembly  10  of the preferred embodiment are described. The screen door assembly  10  includes an assembly frame  20  sized to substantially completely surround the opening  14  in the patio doorway  12 . The frame  20  is preferably affixed to the doorway  12  so that the frame  20  remains stationary relative to the doorway  12 . For clarity, the frame  20  can be referred to as the secondary frame  20 , with the screen door  30  having a screen frame  32  about a perimeter thereof that acts as a primary frame  32 . At least one and preferably two screen doors  30  are pivotably attached to the frame  20  through a hinge  40 . The hinge  40  allows each door  30  to pivot both inward through the doorway  12  and outward away from the doorway  12 . 
     Preferably, the hinge  40  is in the form of a two-point hinge  40  including a lower portion pivotably connecting a bottom portion of the adjacent door  30  to a lower portion of the frame  20 . The two-point hinge  40  additionally includes an upper portion pivotably connecting a top portion of the adjacent door  30  to an upper portion of the frame  20 . Preferably, the upper portion and lower portion of the hinge  40  are aligned with a common substantially vertically oriented pivoting axis for each door  30 . 
     A knuckle joint  50  is provided adjacent the lower portion of the two-point hinge  40  (FIGS.  3 - 5 ). Each knuckle joint  50  includes a knuckle  80 , ramps  70 , wings  100  and a recess  110  which together provide a bias encouraging the adjacent door  30  toward a closed position. Specifically, the wings  100  are oriented so that they ride up a ramp  70  as the door  30  is opened away from the closed position. Gravitational forces acting on the door tend to cause the door to rotate back to the closed position as the wings  100  slide back down the ramps  70 . A knuckle  80  and recess  110  have matching surfaces when the adjacent door  30  is in the closed position. The knuckle  80  and recess  110  thus help hold the adjacent door  30  in the closed position unless forces are applied to the door  30  to open the door  30 , such as by a user pushing on the door  30 . The various structures of the knuckle joint  50  additionally provide a means to elevate the door  30  when the door  30  in opened away from the closed position. 
     The upper portion of the hinge  40  is configured as a recoil joint  140 . The recoil joint  140  includes a top pin  160  to keep the upper portion of the hinge  40  aligned with the pivoting axis. A compression spring  200  gets compressed when the adjacent door  30  is elevated relative to the frame  20 . The compression spring  200  thus works in conjunction with gravity to increase downward forces on the adjacent door  30  when the door  30  is pivoted away from the closed position and elevated by the wings  100  riding up the ramps  70 . The compression spring  200  thus assists in encouraging the adjacent door  30  back to the closed position. Notches  102  in the wings  100  can straddle crests  76  of the ramps  70  so that the door  30  remains detained when rotated to this stop position, preferably corresponding with a fully open position for the door  30 . The doors  30  can thus be held open automatically when desired. 
     More particularly, and with particular reference to FIGS. 1 and 2, details of the frame  20  are described. The door assembly  10  is mounted to the structure (i.e. a house) adjacent the patio doorway  12 . The patio doorway  12  of the structure typically has one or more patio doors that are mounted in parallel planes either fixed or on tracks within the patio doorway  12 . At least one of the patio doors slides along the tracks so that when it is retracted a portion of the patio doorway  12  forms an opening  14 . Typically, the patio doors are solid and have glass or screen paneling. 
     The frame  20  of the assembly  10  preferably includes four sides, including an upper portion, a lower portion and two side portions each extending from the upper portion to the lower portion, and dimensioned to allow the frame  20  to be attached to the structure adjacent the patio doorway  12 , typically on an exterior of the structure. The frame  20  is made of a substantially rigid material, such as that used for the patio doorway  12  frame, such as aluminum or similar material. The rigidity of the frame  20  allows the frame  20  to be positioned adjacent the patio doorway  12 , either free standing or affixed to the patio doorway  12  jambs or adjacent portions of the structure. The frame  20  is adaptable to fit the openings of most patio doorways provided the opening is sufficiently large to receive all four sides of the frame  20 . 
     Trim  22  is provided with the door assembly  10  to fill in any gaps  16  left between the top of the frame  20  and the patio doorway  12  with large vertical dimensions. For example, FIG. 1 shows a patio doorway  12  with a large vertical dimension and the trim  22  is mounted between the frame  20  and the patio doorway  12  to provide a seal where the frame  20  does not cover the opening through the doorway  12 . The trim  22  is made of weatherstripping material or the like that can preferably be cut to size. 
     With continuing reference to FIGS. 1 and 2, details of the screen doors  30  are described. Each screen door  30  includes a screen frame  32  surrounding and supporting one or more screen panels  34 . A suitable screen panel  34  is mounted within the screen frame  32  with the screen frame  32  forming the edges of the screen door  30 . The screen door  30  further includes a handle  36  and weatherstripping  38 . The weatherstripping  38  can be attached to all four sides of the screen door  30  and provides a weatherproof seal. 
     Each door assembly  10  further includes a two-point hinge  40 . The two-point hinge  40  provides an axis for pivoting of the screen door  30  and pivotably connects the screen door  30  to the frame  20  at a top of the screen door  30  and a bottom of the screen door  30 . The two-point hinge  40  has two axially aligned portions, including an upper hinge portion and a lower hinge portion, that work together to pivotably support the door  30  relative to the frame  20  and provide the door  30  with a bias towards a closed position, provide bidirectional swing of the doors into and out of the structure and provide a means to detain the doors  30  on a stop position. The upper hinge portion or recoil joint  140  is mounted between the top portion of the screen door  30  and the frame  20 . The lower hinge portion or knuckle joint  50  is positioned between the bottom portion of the screen door  30  and the frame  20 . 
     FIG. 2 shows the placement of each two-point hinge  40  for an embodiment that divides the screen door  30  vertically into separately openable and independently hinged doors  30 . The doors  30  include a portion of a hinge  40  mounted between the screen frame  32  of each door  30  and the secondary frame  20 , adjacent the four corners of the secondary frame  20 . In FIG. 2, a left door  30  is shown opening outwardly, while a right door  30  is shown opening inwardly. Alternatively, one door  30  rather than two can be used. When only one door  30  is used, only one two-point hinge  40  is needed. The one two-point hinge  40  for such a single door can be placed on either side of the door between the top and bottom of the screen frame  32  and secondary frame  20 . 
     The two-point hinge  40  includes a knuckle joint  50  forming the lower hinge portion and a recoil joint  140  forming the upper hinge portion. FIGS. 3,  4  and  5  show the knuckle joint  50  mounted between the screen door  30  and frame  20 . FIGS. 6,  7  and  8  show the knuckle joint  50  free from the framings and mountings of the door assembly  10  and match the perspectives of the screen door  30  in pivoting motion represented in FIGS. 3,  4  and  5  respectively. FIGS. 9 and 10 show full sectional views of the knuckle joint  50 . 
     The knuckle joint  50  is made up of two adjacent cooperating members: a stationary member affixed to the frame  20 , identified as the knuckle base  60  and a pivoting member affixed to the screen door  30  and identified as the heel assembly  90 . The knuckle base  60  extends up from the frame  20  and provides stationary surfaces for adjacent surfaces of the heel assembly  90  to pivot upon. The heel assembly  90  extends down from the screen door  30  and provides pivoting surfaces that ride on the adjacent surfaces of the knuckle base  60 . 
     The knuckle base  60  is generally L-shaped (when oriented to support the left door  30 ) or reverse L-shaped (for the right door  30 ). A horizontal member  62  and vertical member  64  form the L-shape of the knuckle base  50 . These legs  62  and  64  reside within a hollow interior of the frame  20  at a lower corner. Other shapes suitable for corner-frame mounting may be used to form the knuckle base  60 , as well. Mounting holes  66  are provided for receiving a fastener, such as a screw or rivet to facilitate the fastening of the knuckle base  60  to the frame  20 . The knuckle base  60  is preferably made of an injection moldable material to facilitate formation of the various surfaces of the base  60 . The legs  62  and  64  of the knuckle base  60  have a lattice pattern to minimize material and weight, without compromising strength. 
     A knuckle  80  extends up from the horizontal member  62  of the L-shaped knuckle base  60 . The knuckle  80  has a hollow center for receiving the knuckle pin  130 . The knuckle pin  130  extends vertically along the pivoting axis of the door  30 . The pin  130  keeps the door  30  aligned with the frame  20  as the door  30  pivots. The pin  130  allows the door  30  to translate vertically somewhat during installation of the door  30  into the frame  20  and during pivoting of the door  30 . 
     The knuckle  80  preferably has a non-circular cross section with two diagonal slopes  82  tapering up to a ridge  84 . The ridge  84  extends horizontally with the pin  130  extending up from the hollow center in a middle of the ridge  84 . The slopes  82  cooperate with a recess  110  in the heel assembly  90  of the door  30 , as described in detail below. 
     The knuckle  80  is preferably flanked by two ramps  70 . Each ramp  70  includes a pair of tapered slopes  72  tapering up to a crest  76 . The slopes  72  are preferably somewhat arcuate about a center of curvature at the pivoting axis for the door  30 . The ramps  70  cooperate with the wings  100  described in detail below. 
     The knuckle joint  50  further includes a heel assembly  90 . A foot  120  includes the heel assembly  90  thereon and is provided with mounting holes  122  for mounting of the heel assembly  90  to the screen door  30 . The foot  120  is analogous to the horizontal member  62  and vertical member  64  of the knuckle base  60  and is lattice patterned, as well. 
     The heel assembly  90  includes a recess  110  open in a downwardly facing direction. The recess  110  is non-circular in cross-section and preferably has a contour that is complemental with the contour of the knuckle  80 . The knuckle  80  can thus extend up into the recess  110 . The recess  110  includes diagonal surfaces  112  that are adjacent the diagonal slopes  82  of the knuckle  80  when the recess  110  is aligned with the knuckle  80 . When the door  30  is pivoted, the recess  110  and knuckle  80  come out of alignment and the recess  110  is caused to ride up on the knuckle  80 , thus providing one means to elevate the door  30 . 
     The recess  110  is flanked by two wings  100 . The wings  100  extend out from the recess  110  a distance similar to a distance the ramps  70  extend out from the knuckle pin  130 . The wings  100  have a proper height to abut the ramps as the recess  100  abuts the knuckle  80 . As the door  30  is pivoted, the wings  100  ride up the slopes  72  of the ramps  70 . Because each of the two ramps  70  includes two slopes  72 , wings  100  ride up slopes  72  of separate ramps  70  when the door is pivoted in either direction. 
     When the door  30  is pivoted to a fully open position, the wings  100  have notches  102  which straddle the crest  76  of each ramp  70 . At this location, the door  30  is held open. Otherwise, gravitational forces on the door  30  cause the wings  100  to slide down the slopes  72  and return the door  30  to the closed position. 
     The upper hinge portion or recoil joint  140  of the two-point hinge  40  is shown in FIG.  11 . The recoil joint  140  includes a frame cavity  150  located within the frame  20 . The frame cavity  150  holds a top pin  160  which connects to the screen door  30  section of the recoil joint  140 . Within the screen door  30  section, the recoil joint  140  further includes a collar  170  for stabilizing the top pin  160  in its connection between the frame  20  and screen door  30 . In addition, the screen door  30  has a vertically extending hollow bore providing a housing  180  for a plunger  190 . The housing  180  holds the plunger  190  and a compression spring  200  beneath the plunger  190 . The top pin  160  is preferably connected to the plunger  190 . The collar  170  keeps the plunger  190  and pin  160 , as well as the spring  200  trapped within the housing  180 . 
     When the door  30  is installed, the pin  160  is fed up into the cavity  150 . The spring  200  is compressed by further elevating the door  30  until the recess  110  of the heel assembly  90  and the knuckle pin bore  132  can be placed over the knuckle pin  130 . The door is then in place for pivoting. Alternatively, the pin  130  can be fixed within the bore  132  and the pin  130  fed into the hollow center in the ridge  84  of the knuckle  80 . 
     In use and operation, and with particular reference to FIGS. 1 and 2, details of the operation of the screen door assembly  10  of this invention are described. Initially, the user selects the doorway  12  that is to be fitted with the screen door assembly  10  of this invention. Typically, such an appropriate doorway  12  would be a sliding glass door opening  14 . Alternatively, the screen door assembly  10  could be fitted adjacent French doors or other appropriate doorways of a structure. While the assembly  10  of this invention includes screen doors  30  in the preferred embodiment, it is not strictly required that only screen doors  30  be included in this assembly  10 . Rather, other types of doors including transparent doors of glass or other materials, or solid non-transparent doors could be similarly provided as part of the assembly  10  of this invention. 
     Before mounting the assembly  10 , the existing sliding screen door of the sliding glass doorway would typically be removed (but could optionally be left in place slid to an open position). The frame  20  of the assembly  10  is then affixed to the doorway  12  surrounding the opening  14  and preferably on an exterior of the structure in which the doorway  12  is formed. The lower portion of the frame  20  is preferably adjacent a bottom of the doorway  12  so that the lower portion of the frame  20  does not present a tripping hazard for people walking out through the doorway  12  and over the lower portion of the frame  20 . 
     The side portions of the frame  20  are preferably adjacent sides of the doorway  12 . Preferably, the side portions of the frame  20  extend slightly into the opening  14  of the doorway  12  so that the doors  30  can pivot both inward through the opening  14  and into the structure in which the doorway  12  is located as well as outward away from the opening  14  in the doorway  12 . Preferably, the width of the frame  20  is slightly less than a width of the opening  14  to provide the doors  30  with clearance as discussed above. While the frame  20  is shown with a fixed width, the frame can be configured to be width adjustable if needed to accommodate openings  14  of different widths. The frame  20  can be affixed to the structure adjacent the doorway  12  using appropriate fasteners, such as screws to affix the frame  20  to the doorway  12  surrounding the opening  14 . Alternatively, an adhesive could be utilized to bond the frame  20  to the doorway  12 . Preferably, the frame  20  has its upper portion spaced above the lower portion with a fixed height. To accommodate doorways  12  of different heights, a piece of trim  22  is provided. This trim  22  is affixed to the doorway  12  to fill a gap  16  between the upper portion of the frame  20  and a top of the doorway  12 . The trim  22  is preferably formed of a material which can easily be cut to size so that doorways  12  of different heights can be accommodated. 
     Once the frame  20  and trim  22  have been affixed to the doorway  12 , the doors  30  are ready to be installed into the frame  20 . Because the frame  20  completely surrounds the opening  14 , various different portions of the frame  20  do not require alignment together for proper alignment and operation of the doors  30 . Preferably, the assembly  10  includes two doors  30  which each fill half of the opening  14  within the frame  20 . As discussed above, the doors  30  have their pins  130 ,  160  (FIGS. 10 and 11) aligned with associated recesses in the frame  20  with the spring  200  compressed initially to allow both pins  130 ,  160  to enter the appropriate recesses in the frame  20 . The spring  200  then causes the pins  130 ,  160  to extend into the adjacent recesses and the door  30  is held within the frame  20 . Once in position, the doors  30  can pivot about two parallel pivoting axes but are prevented from any other rotation or translation, other than slight vertical translation when the spring  200  is compressed. 
     With particular reference to FIGS. 3-10, details of the pivoting operation of the doors  30  are described. The knuckle joint  50 , including the knuckle base  60  and the heel assembly  90 , provides many of the pivoting functional details of the assembly  10  of this invention. The recess  110  of the heel assembly  90  and knuckle  80  of the knuckle base  60  are configured to have their contours complementally mate together with the knuckle  80  extending up into the recess  110  when the door  30  is in a closed position. Preferably, this closed position is a position in which the door  30  occludes a maximum amount of the opening  14 . However, it is only strictly necessary that this closed position be a position in which the opening  14  is more occluded than a second open position. Most preferably, the open position of the door  30  is a position where the door.  30  is pivoted 90° away from the frame  20  and leaves the opening  14  totally open. However, it is only strictly necessary that the open position provide less occlusion of the opening  14  in the frame  20  than the closed position. 
     The compression spring  200  provides a force downward on the door  30 . Gravitational forces also act downward on the door  30 . Hence, the door  30  remains in a lowermost position with the recess  110  aligned with the knuckle  80 , so that the door  30  is biased towards the closed position. While this bias is preferably in the form of the recess  110  and knuckle  80 , other forms of bias structure could be provided to apply forces tending to return the door  30  to the closed position. While it is not strictly necessary to include the compression spring  200  to enhance the force with which the door  30  is biased toward the closed position, inclusion of such a spring  200  is preferred. 
     The recess  110  and knuckle  80  do not prevent the door  30  from rotating. When forces are applied to the door  30  tending to cause the door  30  to pivot about the pivoting axis, the knuckle pin  130  keeps the recess  110  aligned with the knuckle  80  and the heel assembly  90  of the door  30  rotates relative to the knuckle base  60 . Because the recess  110  and knuckle  80  do not have circular cross-sections, but rather include diagonal slopes  82  and diagonal surfaces  112 , the heel assembly  90  and associated door  30  translate vertically upward as the door  30  rotates. When opening forces applied to the door  30  are removed, gravity and compression spring  200  forces act on the door  30  to cause the recess  110  to slide back down onto the knuckle  80  and be recentered in the closed position for the door  30 . 
     When the door  30  is pivoted to the open position, the recess  110  rides up entirely off of the knuckle  80 . In this position, the diagonal surfaces  112  of the recess  110  are away from the diagonal slopes  82  of the knuckle  80 . Downward forces acting on the door  80  are held between the recess and the knuckle  80  on a ridge  84  of the knuckle  80  and no pivoting return forces are exerted on the door  30 . Thus, the door  30  tends to remain in the open position. This detained or stop position of the door  30  conveniently allows the door  30  to remain open when desired in a fully open position. A user can cause the door  30  to return to a closed position by merely applying a slight force towards closing the door  30 . The diagonal surfaces  112  of the recess  110  and diagonal slopes  82  of the knuckle  80  then act together to encourage the door  30  to rotate back to the closed position. The knuckle  80  and recess  110  thus provide one means to both detain the door  30  when in an open position and to return the door  30  to the closed position when moved out of the detained position. 
     In addition to the knuckle  80  and recess  110 , the knuckle base  60  and heel assembly  90  preferably additionally include the ramp  70  and wing  100  combination described in detail above. When the door  30  is rotated away from the closed position in either direction, the wings  100  ride up the ramps  70 . The wings  100  and ramps  70  thus coact to encourage the door  30  to be biased towards the closed position. When the wings  100  ride all of the way up to the crest  76  of the ramps  70 , the notches  102  and the wings  100  straddle the crest  76  of each ramp  70 . This straddling action causes the doors  30  to relatively easily hold the detained open position with the bias toward the closed position neutralized. However, slight closing forces on the doors  30 , such as applied by hands of a user, will cause the doors  30  to return to the closed position. 
     The wings  100  and ramps  70  act together to elevate the door  30  as do the recess  110  and knuckle  180 . While preferably both of these combined structures are provided, it is conceivable that either one of these assemblies could be utilized alone to provide the closing function and elevating function for the door  30 . When the door  30  is moved away from the closed position, the door  30  is elevated by the knuckle  80  and recess  110  interaction and by the wing  100  and ramp  70  interaction. This elevating of the door  30  serendipitously not only assists in biasing the door  30  towards the closed position by compressing the spring  200  and increasing gravitational potential energy, but also increases a clearance experienced by a bottom portion of the door  30  over structures directly inside the doorway  12  or outside the doorway  12 . For instance, if carpeting and/or rugs inside the structure and adjacent the doorway  12  extend slightly above a level of the bottom of the doorway  12  and the frame  20 , the bottom of the door  30  is provided with clearance to avoid these structures when the door  30  is opened. The doors  30  thus conveniently can open and close in both an inward and an outward fashion relative to the doorway  12  with maximum clearance to avoid obstacles and still provide a tight seal when closed to prevent migration of bugs past the door  30 . 
     This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this disclosure. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. When structures of this invention are identified as being coupled together, such language should be interpreted broadly to include the structures being coupled directly together or coupled together through intervening structures. Unless specifically limited, such coupling could be permanent or temporary and either in a rigid fashion or in a fashion which allows pivoting, sliding or other relative motion while still providing some form of attachment.