Patent Publication Number: US-6907641-B1

Title: Reinforcement bracket for a bi-fold closet door

Description:
BACKGROUND 
   1. Field of the Invention 
   This invention pertains to bi-fold closet doors, and more particularly to a corner bracket that reinforces the door&#39;s attachment to the doorjamb track. 
   2. Prior Art 
   Bi-fold doors are commonly used with closets. Typically, a bi-fold door has two pair of two doors hinged together, a hinge door pivotally connected at its top and bottom near the vertical member of the doorjamb and a lead door guided in an overhead track on the upper horizontal member of the doorjamb. The lead door has a roller on a peg extending upwardly out of a bore in the door top near the door upper corner. The roller moves in the track to guide the doors during opening and closing as the doors fold on the hinges that join them. 
   The overhead track is typically U-shaped with flanges depending from a web that is screwed into the horizontal member of the doorjamb. Inwardly directed ledges typically extend from flange distal ends toward each other creating a slot entry into the channel. The peg then passes through the slot and the roller is retained in the channel by the opposing channel ledges. At the door, the peg is press-fit into the door bore. 
   This typical bi-fold configuration is provided convenient access to the closet but has been disadvantageous because when bi-fold doors are repeatedly slammed open or closed, as commonly happens in service, lateral forces act through the peg and roller in stopping door momentum eventually results in damage to the door. As the peg transmits the forces to the door, eventually the door, typically made out of wood or wood products, is unable to sustain the repeated forces and the bore becomes enlarged or the door splinters at the bore. Repair of this damage to the door is a common and can become a costly maintenance item to apartment complexes. Commonly, the peg splinters the side of the door, indicating that the door is generally able to sustain the component of these forces directed toward the door side edge but the splintering door side is unable to sustain the component of the forces in the direction of the door side, which force component is referred to below as the damaging force or forces. 
   It is known to have a narrow metal corner bracket screwed to the door corner with a horizontal member and vertical member joining orthogonally to form an right angle bracket and having a matching bracket hole in the horizontal member aligned with the door bore over the door top edge. The corner bracket thus mounts to the door edge corner with vertical member screwed onto the door side edge. Although such a bracket improves distribution of the forces to door, it also has disadvantages. Screws in the corner bracket that attach the bracket to the door are still at the door edges and are subject to tearing through the soft wood of the door edge. The vertical member of the corner bracket is unsightly and is also noticeable to a person in front of the door. To avoid the soft edge wood, the bracket might be provided with a lip extending over the door edge to the door side through which screws might secure the bracket to the door back side near the door edge instead of or in addition to the soft door edge. 
   However, even with additional bracket screws in or near the door edges sharing the forces to the door, repeated forces may splinter the door. And for a bracket with a lip, a different sized bracket must be provided for each sized door if the matching bracket hole is to align with the door bore in the center of the door edge. Also, door bores are of different sizes for different manufacturers again requiring a bracket customized for each bore size. To manufacture a set of brackets that meets all of the varied conditions quickly becomes uneconomic. 
   SUMMARY 
   These disadvantages are resolved with a single bracket that conveys repeated lateral, even abusive, forces from the channel through a common peg and roller to the bi-fold doors without damaging the door. 
   The bracket comprises a broad angle bracket with a horizontal edge plate and a vertical brace plate meeting orthogonally at a bracket corner where the vertical brace plate extends down from the horizontal edge plate a substantial length. To absorb change in momentum from the door slamming to a stop, the brace plate length is at least that of the depth of the horizontal edge plate from the brace plate and more commonly the length of the horizontal edge plate along its union with the brace plate at the bracket corner. For purposes throughout this disclosure, the depth of the horizontal edge plate refers to a direction orthogonal to the brace plate and along the thickness of the door at the top of the door when the bracket is installed and the length of the horizontal edge plate refers to a direction orthogonal to the depth of the horizontal edge plate and parallel with the bracket corner. 
   When mounted to a door with the horizontal edge plate over a door top edge and the vertical brace plate mounted on the door back side, the bracket is not viewable from the front of the door. That is, the depth of the bracket horizontal edge plate is less than the door thickness so it does not extend past the door front side; as noted, the brace plate is broad for distributing the load from the peg over a broad area of the door back side when mounting against it. The peg must position near the door corner for it to serve as a door guide in the overhead channel. The horizontal edge plate therefore has a vertical post extending upwardly therefrom to which a roller may be attached. Typically, the post has a longitudinal post bore for receiving a peg having a roller on a peg upper end outside of the post. 
   Alternatively, the horizontal edge plate may have a hole no larger than the drilled hole in the door top edge in which the peg commonly is received. To align the brace plate hole with the door hole the bracket may include a vertical edge plate orthogonal to both the horizontal edge plate and the vertical brace plate, extending between them. The vertical edge plate then measures the distance from the door side edge to the door hole as the same distance between the bracket vertical edge plate and the bracket peg hole. 
   Thus, the damaging lateral forces are no longer conveyed through the peg to the door at the door hole or even through additional screws in or near the door edge to the door through a corner bracket. Instead those damaging forces are transmitted through the peg fitting in the bracket peg hole and then broadly to the brace plate. The consequence is that screws that secure the bracket to the door no longer are convey forces to the peg, but are primarily for securing the bracket to the door. That is, the impact of slamming the door that previously would cause the peg to splinter the side of the door is absorbed broadly over the brace plate. In effect, the peg stops the bracket instead of stopping the door as in prior configurations; the door is stopped as being part of the bracket so the stopping force is dissipated over the full area of the bracket brace plate. The door is effectively running into a broad plate rather than a thin peg. The door about the door hole and the plate screws do not absorb the damaging lateral forces. Thus, damage to the door is averted. 
   To accommodate a door bore smaller than the peg hole provided in the bracket, one or more cylindrical wafer plugs are provided having a portion with an outer diameter matching the peg hole and a plug bore matching the door bore. The wafer plug then adapts the bracket to the smaller door bore by inserting in the bracket peg hole. Several wafer plugs of differing plug bores adapt the bracket to the wide variety of doors. 
   To accommodate doors of differing thickness with the plate peg hole centered in the door edge, a spacer plate is provided for placement between the bracket brace plate and the door side. Doors are typically either 1⅛ inches or 1⅜ inches. If the bracket were configured to fit a 1⅜ inch door, the bracket is centered in the 1⅜ door by employing a spacer plate with a width of half of the difference in the door widths, or ⅛ inch. Screw holes are in the spacer plate aligned with screw holes in the bracket brace plate. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the bracket of the present invention shown with a wafer plug and a spacer plate. 
       FIG. 2  is an perspective view of the bracket including a post extending upward from the bracket with a longitudinal hole for receiving a peg on which a roller is rotatably mounted. 
       FIGS. 3   a ,  3   b , and  3   c  is top, end and side views of the bracket of  FIG. 2 . of  FIG. 2  shown on a door. 
       FIG. 4  is a perspective view of the bracket with a vertical edge plate orthogonal to both the horizontal edge plate and the brace plate forming a cubical corner, shown in relation to a door corner. 
       FIG. 5  is a perspective view of the bracket post mounted by screws on bracket horizontal edge plate. 
       FIG. 6  is a perspective view of the bracket with a triangular brace plate mounted on a door back side and top edge. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The bi-fold door bracket  10  of the present invention is provided for attachment on a support corner  100  of a typical bi-fold door  102  with top and side edges  104  and  106  and a back side  108  and roller  110  on a peg  112  which roller moves in an overhead channel  114  to guide the door as it folds and unfolds. The bracket  10  primarily comprises a horizontal edge plate  12 , with a depth D sized less than the door top edge  104  and a length L greater than its depth D, and a vertical brace plate  14  with a top  16  meeting the horizontal edge plate length orthogonally L at a bracket corner  18 . To distribute impact forces to the door back side  108  when mounted on the door  102 , the brace plate  14  has a vertical height H at least as long as the depth D of the horizontal edge plate  12  from the brace plate  14  and more commonly at least as long as the horizontal edge plate length L therein providing a broad surface mountable in face-to-face contact with the door  102 . The horizontal edge plate  12  is typically of square shape but may also be of triangular shape. 
   The bracket horizontal edge plate  12  includes a hole  20  adapted to receive the peg  112  as a connection apparatus of the peg  112  to the door  102  located to align with a door hole  116  drilled to receive the peg  112  when the bracket  10  is mounted to a door  102 , the bracket  10  interposing connection from the overhead channel  114  which in turn connects to the door  102  but not at the door hole  116  but over the broad area of the brace plate  14 . 
   In an alternative embodiment, the bracket  10  may comprise a vertical, typically tubular, post  22  extending upwardly from the horizontal edge plate  12  with a longitudinal post bore  24  sized to receive the peg  112 . The bore  24  is located to align approximately with the door hole  116  when the bracket  10  is mounted to a door  102 , substituting the post bore  24  for the door hole  116  in providing an improved interconnection between the peg  112  and the bracket  10  and hence the door  102 . The post  22  may be integrated into the bracket horizontal edge plate  12  or it may comprise a tubular member  26  removably mounted, by screws  120  or the equivalent, to the bracket horizontal edge plate  12  with the tubular member  26  approximately over the door hole  116  provided to receive the peg  112  when the bracket  10  is mounted to a door  102 . The peg  112  is then removably receivable into the tubular member  26 . 
   To adapt a single sized bracket with a single sized hole, which may be larger than the peg on some doors, a cylindrical wafer plug  30  is provided as an insert into the bracket hole  20 . The wafer plug  30  has a cylindrical portion  32  with an outer diameter  34  matching and received into the bracket hole  20  and a plug bore  36  matching the peg  112 , the wafer plug  30  effectively reducing the bracket hole  20  to the size of the peg. To adapt the single sized bracket to doors of different width and therefore different position of the door hole, a spacer plate  38  is provided, intended to fit in face-to-face contact with the brace plate  14  under the horizontal edge plate  12  to space the brace plate  14  a measured distance from the door back side  108  so the bracket hole  20  in the horizontal edge plate  12  aligns with a door hole  116  provided to receive the peg  112 . 
   The bracket  10  may further comprise a vertical edge plate  40  orthogonal to both the horizontal edge plate  12  and the vertical brace plate  14  for further securing the bracket  10  to the door  102  and to measure the location of the bracket  10  from the door side edge  106  as the vertical brace plate  14  is mounted in face-to-face contact with the door side edge  106 . The vertical edge plate  40  extends between the horizontal edge plate  12  and brace plate  14 , together forming a cubical corner sized to fit in face-to-face contact with the door top and side edges and back side.