Abstract:
A door is constructed with a separate member joined to the door edge by a tongue-and-groove coupling and screws so as to be readily removable and replaceable. The separate member sustains the impacts imparted to the door by carts or wagons pushed past the door and can be readily replaced when damaged, thus avoiding replacement of the entire door. A flexible cover snaps over the outer surface of the separate member to add impact resistance and aesthetic appeal. Intumescent strips may be inserted inside or outside of the cover to enhance sealing between the door, and at the adjacent door or door frame, thereby improving the fire resistance rating of the door. Accent strips or reveals of contrasting or complementary colors may be incorporated to add to the aesthetic appeal of the door. The door construction is of particular utility in schools, health care facilities and other institutions.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to door constructions and more particularly, to replaceable door edge arrangements.  
       BACKGROUND OF THE INVENTION  
       [0002]     One popular form of vertically hung doors typically comprises a wooden frame defining outer dimensions of the door, panels of sheet material, such as plywood, plastic or metal covering the frame or both sides, and a core within the frame, which may be solid or hollow.  
         [0003]     In certain high traffic environments, for example, schools, hospitals and other types of health care institutions, doors are often subjected to impacts from carts, wagons, dollies, etc. which take their toll on the doors, particularly along their free edges and the hinged edges. Nicks, gouges and cracks produced along door edges by such impacts compromise a door&#39;s ability to effect a secure closure, which is particularly important where the door serves as a fire barrier as well as a closure, and mar its aesthetic appearance.  
         [0004]     Heretofore, when a door edge was severely damaged, it was necessary either to replace the door in its entirety or to refinish it. With the latter expedient, the door panels may also have to be replaced and, in any event, the door will have to be refinished as well. The cost of maintaining the structural integrity and appearance of the many doors in a hospital, for example, can become substantial.  
       SUMMARY OF THE INVENTION  
       [0005]     The object of the present invention is to minimize the necessity of replacing or refinishing doors that have been severely damaged along their edges by enabling a damaged door edge to be simply and inexpensively restored.  
         [0006]     The foregoing object is achieved by constructing a door with a replaceable edge strip or stile which, when damaged, can be readily removed and replaced with a new one, thereby restoring the door&#39;s integrity and appearance. In accordance with the invention, this is achieved by so constructing the door such that the replaceable edge strip or the replaceable stile can be removed and replaced without affecting the door frame or door slab, thus eliminating the need for otherwise replacing or refinishing the door. The stile is so configured that it can be covered with a plastic cap that provides an extra layer of protection against damage and helps maintain a snug seal against a doorway or an opposite door.  
         [0007]     Another feature of the invention is the incorporation in the replaceable door edge assembly of an intumescent (heat expanding) material such that in case of fire, the edge is expanded outwardly to effect a tighter seal with the surrounding doorway or opposite door. The fire safety rating of the door is thus improved.  
         [0008]     Still another feature of the invention is the incorporation in the door edge construction of an accent material to provide a reveal, or line of color different than the door panel color, for aesthetic and/or identification purposes. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The foregoing and other features and advantages of the invention will become apparent from the following detailed description thereof, taken in conjunction with the appended drawing, in which:  
         [0010]      FIG. 1  is an oblique view partially cut away, of a door incorporating the present invention;  
         [0011]      FIG. 2  is a cross-section of the door of  FIG. 1 , taken along the line  2 - 2 ;  
         [0012]      FIG. 3  is an enlarged view of the right-hand portion of the cross-section view of  FIG. 2  showing the door edge construction of the invention in greater detail;  
         [0013]      FIGS. 4A, 4B  and  4 C illustrate modifications of the door edge construction of  FIG. 3 ;  
         [0014]      FIG. 5  is an enlarged cross-sectional view similar to  FIG. 3  illustrating the incorporation of an intumescent strip in the door edge construction of the invention;  
         [0015]      FIG. 6  illustrates a modification of the door edge construction of  FIG. 5 ;  
         [0016]      FIGS. 7A, 7B ,  7 C and  7 D illustrate the replaceable door edge construction of the invention incorporating various types of accent strips or reveals;  
         [0017]      FIGS. 8A and 8B  illustrate variations of the invention embodying an alternate tongue and groove arrangement for securing the replaceable stile to the door edge;  
         [0018]      FIG. 9  illustrates a variation of the invention in which the tongue and groove members are covered with metal channels;  
         [0019]      FIG. 10  illustrates a modification of the arrangement of  FIG. 9 ;  
         [0020]      FIGS. 11 and 12  illustrate variations of the arrangement of  FIG. 9 ; and  
         [0021]      FIG. 13  illustrates a replaceable stile arrangement in accordance with the invention in which the width of the replaceable stile is adjustable. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     Turning now to the drawings, in particular  FIGS. 1, 2  and  3 , a door of the type commonly used in health care facilities and the like, but incorporating the present invention, is shown. Such a door  20  typically comprises vertical stiles  22  and top and bottom rails  24 , surrounding a core  26 . The stiles  22  and rails  24  preferably are made of hardwood and the core  26  of particle board, although other materials may be used to provide the necessary strength and rigidity.  
         [0023]     Finish panels  28  cover the particle board core, top and bottom rails and stiles on both sides to provide strength, impact resistance and aesthetic appeal. As seen best in  FIG. 3 , the panels  28  may comprise a hardboard layer  28   a  covered by a decorative plastic cladding  28   b  such as of ACROVYN®, a vinyl acrylic plastic manufactured by Construction Specialties, Inc., Lebanon, N.J. The layers  26 ,  28   a  and  b  are laminated together to form a 5-ply construction. Doors of the type illustrated are manufactured, for example, by Jeld-Wen, Inc.  
         [0024]     Doors  20  may be made in dimensions to fit various size doorways in which they are mounted. As will be appreciated, the door  20  may be hinged to swing around along either vertical edge to suit the application. In a typical installation often found in health care facilities, a pair of such doors are hinged at opposite edges to close a wide hallway and are swingable in both directions so that rolling beds, carts, etc may be pushed through without the need to hold the door open.  
         [0025]     As discussed above, such doors are subjected to repeated, severe impact by beds, carts, etc., as they are pushed through the doors, often resulting in significant damage to the free vertical edges of the doors. Not only is the appearance of the door thus marred, the integrity of the closure and its fire resistance capability are degraded. Heretofore, in the case of significant edge damage, it was necessary to completely replace a damaged door with a new one to restore the closure&#39;s appearance and integrity, at substantial cost.  
         [0026]     In accordance with the present invention, the vertical edges of a door such as described herein are fabricated with separable edge assemblies that can be readily replaced if damaged, thereby avoiding the necessity of complete door replacement and greatly reducing the cost of restoring the door&#39;s appearance and integrity.  
         [0027]     A preferred embodiment of the removal door edge arrangement of the invention is shown in  FIGS. 1, 2  and  3 ; most clearly in the enlarged section through a door edge of  FIG. 3 . The vertical door stile is indicated at  22  and the replaceable edge assembly indicated at  30 . The latter comprises replaceable stile  32 , preferably of hardwood, extending the full length of the edge stile  22  and a plastic cover  34  secured over replaceable stile  32 . Stile  22  is milled with a longitudinal tapered groove  22   a  and replaceable stile  32  with a longitudinally extending complementary tapered spline  32   a,  forming a snug tongue-and-groove mating of stile  22  and replaceable stile  32 . A plurality, e.g., 4, of screws  36 , spaced along the door edge, firmly but releasably secure replaceable stile  32  to stile  22 . If desired, spots of glue may also be applied between stile  22  and replaceable stile  32  to more firmly hold them together, while still allowing replaceable stile  32  to be removed when required.  
         [0028]     Cover  34  may be formed of ACROVYN® or other relatively hard but resilient material, such as aluminum or stainless steel, with inwardly directed flanges  34   a  along both edges. Cover  34  is formed to be of the same shape as the outer surface of replaceable stile  32 , e.g., generally rectangular with rounded corners. Replaceable stile  32  is provided with rectangular indents  32   b  along both inner longitudinal edges, such that when stile  22  and replaceable stile  32  are joined, rectangular grooves  32   b  are formed therebetween extending the full length of the door. These grooves snugly receive the flanges  34   a  of cover  34 . To remove a damaged cover from a door, one of the flanges  34   a  is pried out of its groove and the cover bent away to release the other flange. To install a new cover, one of the flanges is inserted into its groove and the cover pressed toward the outer surface of replaceable stile  32  until the other flange snaps into the other groove.  
         [0029]     It will be understood that the curvature of the corners of the stile and cover combination discussed and illustrated may be varied to suit the particular application. For example, for paired swinging doors, such as often found across hospital passageways, the corner curvature will be of greater radius than single doors, to provide the required clearance.  
         [0030]     It will also be understood that the cover  34  need not be removable, but may be permanently secured to its replaceable stile  32 , such as by a suitable adhesive. In such an arrangement, flanges  34   a  and indents  32   b  may be unnecessary.  
         [0031]      FIGS. 4A, 4B  and  4 C illustrate alternative forms of the tongue-and-groove coupling of  FIG. 3 , with the screws omitted for the sake of clarity. In  FIG. 4A , a dovetail spline  42  mates with a corresponding groove  44 ; in  FIG. 4B , the spline  46  has a partially circular cross-section to mate with a partially circular groove  48 ; and in  FIG. 4C , the spline  50  and groove  52  are rectangular in cross-section. It will be understood that other variations of the tongue-and-groove cross-sections may be used as desired.  
         [0032]      FIG. 5  illustrates another embodiment which further enhances the fire resistance advantages of doors of the invention. A heat-expansion or intumescent strip  52  extends the full length of the door edge and is adhered in a groove  54  milled along the outer edge of replaceable stile  32 . Cover  34  may have a complementary groove along its inner surface to accommodate the strip as well. The strip  52  is covered by outer cover  34  when the latter is snapped in place. At normal room temperatures, strip  52  maintains its normal thickness. In case of fire or extreme heat adjacent the door, strip  52  expands, pushing cover  34  outwardly to tighten the seal between the edge of the door and an adjacent door or doorframe, thus increasing the fire resistance rating of the door.  
         [0033]     A variation of the arrangement of  FIG. 5  is illustrated in  FIG. 6  wherein the intumescent strip  52  is adhered in a groove  34   a  formed in the outer edge of cover  34 , the inward extension of the cover  34  fitting in a groove milled along the outer edge of replaceable stile  32 .  
         [0034]     It will be understood that in the embodiments of  FIGS. 5 and 6 , any of the tongue-and-groove couplings described above may be used in place of the configurations illustrated.  
         [0035]     To improve the appearance of the door, an accent strip or reveal, of a contrasting or complementary color to the remainder of the door surface, may be incorporated in the door edge arrangements of FIGS.  3  to  6 . In the embodiment of  FIG. 7A , longitudinal grooves  60  are milled along opposite sides of replaceable stile  32 , inwardly of its interior face, for receiving the flanges  34   a  of cover  34 , leaving exposed narrow longitudinal surfaces  62  on opposite sides of the stile, between cover  34  and the panels  28 . These exposed surfaces  62  may be painted in any aesthetically pleasing color.  
         [0036]     The reveal or accent strip may also be provided by insertion of a suitably colored strip of accent material in a slot provided between the stile  22  and replaceable stile  32 , as shown in  FIG. 7B . As seen, stepped indents  64  are provided along each inner corner of replaceable stile  32  to receive the flanges of cover  34  and accent strips  66 . The strips  66  may be of PVC plastic, aluminum, stainless steel or other material having their outer surfaces ridged and slightly thicker than the grooves created upon joinder of replaceable stile  32  to stile  22 . The strips  66  are pressed into the grooves after cover  34  is inserted and the ridged surfaces resist any tendency of the strips to move out of the grooves.  
         [0037]     A variation of the accent strip of  FIG. 7B  is illustrated in  FIG. 7C . In this modification, the inside longitudinal edges of replaceable stile  32  are milled to provide both stepped indents and longitudinal grooves for receiving L-shaped accent strips  68 . One leg of each accent strip extends outwardly to just below the respective outer surface of the door with its edge exposed when replaceable stile  32  is joined to stile  22  with the accent strip in place.  
         [0038]     In the embodiment of  FIG. 7D , the accent strips comprise opposite exposed edges  70  of a strip  72  sandwiched between stile  22  and replaceable stile  32 .  
         [0039]     The accent strips of FIGS.  7 B-D may be made of any suitable material, including PVC plastic, aluminum and stainless steel.  
         [0040]      FIGS. 8A and 8B  illustrate variations of the tongue and groove arrangements of the invention shown in the previous embodiments. In both variations, the groove in the stile  22  is rectangular (as in  FIG. 4C ) and lined with a U-shaped channel  80  having longitudinal ridges  82  formed along both interior sides of the channel. Channel  80  is secured in the rectangular groove milled in stile  22  by screw  84 .  
         [0041]     Adhered along the inner surface of replaceable stile  32  is a tongue plate  86  having integral longitudinal extending flanges  88  with longitudinally extending ridges  90  formed along their outer surfaces. The pair of flanges  88  and channel  80  are dimensioned such that the flanges are snugly received within the channel and the respective ridges  82 ,  90  engaged to secure replaceable stile  32  to stile  22 . Tongue plate  86  may extend the full width of stile  32 , with rounded edges extending slightly beyond the door panel as in  FIG. 8A , or be narrower than the width of the stile and received in a depression milled in the inner surface of replaceable stile  32 , as in  FIG. 8B . In the embodiment of  FIG. 8A , the rounded extensions of the tongue plate  86  may serve as accent strips. In  FIG. 8B , accent strips are provided by inserts  92  between the edges of cover  34  and stile  22 . In both embodiments, intumescent strips  52  may be provided.  
         [0042]     Channel  80  and tongue plate  86  may be made of aluminum or other metal or plastic, as desired.  
         [0043]     In the embodiment of  FIG. 9 , a dovetail tongue and groove coupling between stile  22  and replaceable stile  32  with screw  36 , such as shown in  FIG. 4A , has both tongue  94  and groove  96  covered with channels of thin aluminum, steel, or other material providing low friction slideable surfaces,  98   a  and  98   b,  respectively, which extend to the outer surfaces of the door. The covered channels facilitate the insertion and removal of replaceable stile  32  on stile  22 .  
         [0044]     A variation of the embodiment of  FIG. 9  is shown in  FIG. 10 , in which the extents of the metal channels  100   a  and  100   b  are limited to the extents of the groove and tongue, respectively. This variation of the embodiment includes cover  34  and may include intumescent strip  52 . The space left between stile  22  and replaceable stile  32  is filled with tapered inserts  102 , which serve to wedge the members  22 ,  32  apart and also to provide accent strips.  
         [0045]     In  FIG. 11 , a single metal channel  110  is applied to the dovetail tongue element only and in  FIG. 12 , the single metal channel  112  is extended outwardly between stile  22  and replaceable stile  32  to the door faces with rounded outer edges  114  which provide accent strips.  
         [0046]     To accommodate different door thicknesses, the adjustable width replaceable stile of  FIG. 13  is advantageous. In this embodiment, the replaceable stile is made up of two separate longitudinal elements  132   a  and  132   b,  each having a generally L-shaped cross-section overlying and nesting with each other to be slideable away from each other between a minimum width arrangement wherein the respective longitudinal edges of elements  132   a  and  132   b  are in contact with each other and a maximum width configuration wherein the respective longitudinal edges are separated. Opening  134  is of greater diameter than screw  36  to allow for varying amounts of separation.  
         [0047]     It will be seen from the foregoing that the present invention provides a simple, inexpensive way of repairing damaged doors by allowing replacement only of a removable door edge assembly, thereby saving the considerable exposure of replacing an entire door. Although a number of specific embodiments of the invention above have been illustrated, various modifications thereof will be apparent to those skilled in the art within the spirit of the invention. For example, replaceable stile  32  and cover  34  may be made as a single integral member and joined to stile  22  as shown. Also, the tongue-and-groove coupling between replaceable stile  32  and stile  22  may be eliminated, if desired and any of these variations may be provided with or without intumescent strips. Accordingly, it will be evident that the scope of the invention is to be limited only as set forth in the appended claims.