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The present invention relates to a corner guard assembly for protecting the corners of walls in institutional facilities. In particular, the invention relates to a corner guard assembly which includes a co-extruded vinyl retainer for the assembly. 
     DISCUSSION OF THE RELATED ART 
     In institutional facilities such as hospitals, elderly care centers, and other public buildings, the corner of building walls are exposed to damage from impact resulting from forceful contact with various kinds of wheeled vehicles, such as stretchers, wheelchairs, dining carts and the like. For this reason, the corners of the building wall are commonly provided with a corner guard that will protect the wall surfaces from damage resulting from the impact. 
     Conventional corner guards are normally comprised of an assembly that includes a metallic base plate, often made of aluminum, which overlays the wall surfaces at the corner, and further includes a resilient cover member that is attached over the base plate. Upon impact, the resilient cover member will deform absorbing the force of the impact. Examples of such conventional corner guard assemblies include the devices disclosed in U.S. Pat. No. 3,717,968 issued to Robert W. Olsen, et al, U.S. Pat. No. 4,430,883 issued to Claude P. Balzer et al, and U.S. Pat. No. 5,363,617 issued to Donald W. Miller. 
     Comer guard assemblies are, however, occasionally struck with sufficient force to damage the assembly. In fact, if the impact is significant enough, the cover member will be subjected to a double impact, the first impact occurring when the vehicle strikes the cover member, and the second occurring immediately thereafter when the cover member strikes the base plate. Such impacts can cause cracking, breaking, or indentations of the cover member. Severe impacts may result in a bending and disfiguration of the base plate as well. Such damage is very unsightly and produces a negative image of the facility. 
     Accordingly, an improved corner guard assembly is desired. 
     SUMMARY OF THE INVENTION 
     An improved corner guard assembly designed especially for use in institutional type facilities is presented. The corner guard assembly of the present invention includes a vinyl retainer base plate as well as a vinyl cover guard. More specifically, the corner guard assembly presented herein includes a novel vinyl base plate having a rigid main body portion that is applied over the wall surface at the corner combined with a co-extruded flexible impact bumper at the apex of the main body. 
     The present invention resists exceptionally heavy impact loads without damage or failure to the corner guard assembly. The present invention, which includes the co-extruded vinyl base plate, has been found to be several times stronger than a conventional corner guard assembly using an aluminum retainer base plate. It has also been found to be several times stronger than a corner guard assembly that includes a vinyl base plate but is without the co-extruded impact bumper. 
     Several other advantages are also achieved. For example, the corner guard assembly disclosed herein is substantially lighter in weight compared to conventional corner guard assemblies that include metallic based plates, which make the present invention substantially lighter than prior designs thereby facilitating easier installation and less expensive shipping. The vinyl base plate allows customers to field bend the corner guard to fit almost any angled corner. The two wall surfaces at the corner don&#39;t have to intersect exactly at a right angle. Fastening hardware can be screwed directly into the vinyl retainer and into the wall without pre-drilling or pre-stamping holes, which is required for metallic based plates. The assembly can also be made of 100% recycled plastic. 
     Other objects and advantages of the invention will become apparent from the following detailed description, which, together with the accompanying drawings, sets forth by way of illustration and example certain preferred embodiments of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings, which constitute a part of this specification and include an exemplary embodiment of the present invention, include the following. 
     FIG. 1 is an exploded view illustrating the corner guard assembly of the present invention and the manner in which it is assembled to the corner of a building wall. 
     FIG. 2 is a cross-section view of the co-extruded vinyl base plate of the present invention. 
     FIG. 3 is an enlarged cross-section view of the co-extruded flexible impact bumper at the apex of the base plate. 
     FIG. 4 is a cross section view of the corner guard assembly of the present invention, shown assembled to the corner of a building wall. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 4, a corner  10  of a building wall is defined by the intersection of two wall surfaces. The corner may be formed by assembling at right angles a first panel  11  and a second panel  12  of drywall, sheetrock, or the like. The walls define hallways and corridors for directing pedestrians and wheeled vehicles such as carts, mobile tables, wheelchairs and the like through the building. Thus the corner is subject to impact from such vehicle striking the corner of the wall with various degrees of force. Accordingly, a corner guard assembly  20  is applied to the corner of the building wall. 
     Referring again to FIGS. 1 and 4, the present invention of a corner guard assembly  20  is comprised of a retainer member  21 , a plurality of fasteners  22  for fastening the retainer member to the corner of the building wall, a corresponding cover member  23  assembled over the retainer member, and endcaps  24  assembled to the upper and lower ends of the assembly. 
     The retainer member  21  is an elongated member including a first flat planar portion  25  and a second flat planar portion  26 , the two flat planar portions each extending the entire length of the retainer member. The first flat planar portion  25  is applied over the first wall surface  11 , and the second flat planar portion  26  is applied over the second wall surface  12 . The first flat planar portion  25  intersects the second flat planar portion  26  preferably at an angle that corresponds to the angle of intersection of the first and second wall surfaces  11  and  12 , which normally should be about 90°. The retainer member  21  is made of a plastic material, preferably an extruded polyvinyl chloride plastic material (PVC). In the construction of building walls, the two intersecting wall surfaces  11  and  12  that form the corner  10  are occasional assembled together in a manner that does not form a precise right angle. In that event, the plastic retainer member  21  may be flexed a slight amount in order to properly fit over the corner of the building wall to which the corner assembly is being applied. 
     The first flat planar portion  25  has an offset edge portion  27 . The second flat planar portion  26  has a similar second offset edge portion  28 . When the retainer member  21  is applied to the corner  10  of the wall, the first offset edge portion  27  is raised a slight distance from the surface of the first wall section  11  of the building wall. Likewise, the second offset edge portion  28  is raised a slight distance away from the second wall surface  12 . The first and second raised edge portions  27  and  28  form edges around which the cover member  23  is assembled. 
     As mentioned, the main body portion of the retainer member  21  is fabricated preferably from a rigid PVC material. Rigid polyvinyl chlorides normally have no plasticizes added to the material. One particular grade of material which is known to work satisfactorily is Synergistics Polycor D1015 Natural. The material comes in pellets that are melted and extruded through a die to form the retainer member. The properties of this material include a Shore D hardness scale according to ASTM Standard D2240 of about 80, and a tensile strength according to ASTM Standard D638 of about 6800 psi. Other comparable materials having similar characteristics may be available in the market. 
     At the apex  29  of the retainer member  21 , i.e., at the outer radius of the point where the first flat planar portion  25  intersects the second flat planar portion  26 , a co-extruded flexible PVC impact bumper  30  is applied. The impact bumper  30  is similarly fabricated from pellets of raw plastic material that are melted and extruded through a die into the proper form. Preferably, the main body portion and the impact bumper are simultaneously co-extruded so that the impact bumper is applied to the apex of the main body portion of the retainer member while both materials are warm and soft and thus become integrally bonded to each other. The impact bumper  30  is preferably made from a flexible, rather than a rigid, polyvinyl chloride (PVC) material. Flexible polyvinyl chlorides have a plasticiser added to the materials. One known suitable material is Prime Flexible 7082 b  Natural, available from Prime PVC. Characteristics of this particular material include a Shore A durameter according to ASTM Standard D 2240 of about 80, and a tensile strength according to ASTM Standard D638 of about 1720 psi. Other suitable materials may be available in the market. 
     The retainer member  21  is applied to the corner  10  of the building wall as illustrated in FIG.  1 . Because the retainer member  21  is made from a PVC plastic, the first and second flat planar portions  25  and  26  are able to bend a slight amount relative to each other in order to fit the precise angle of the first and second wall surfaces  11  and  12 , respectively, of the corner  10  of the building wall. The retainer member  21  is fastened to the corner  10  with a plurality of fasteners  22 , preferably self-tapping screws. The screws  22  may be applied virtually anywhere along the length of the retainer member  21 . By pressing and rotating a self-tapping screw  22  into the surface of the retainer member  21 , the screw  22  will protrude through the plastic material of the retainer member  21  and into the drywall or sheet rock substrate. 
     The corner guard assembly  20  further includes a cover member  23  that is assembled over the retainer member. The cover member  23  is also preferably fabricated from a vinyl material, preferably of a decorative color, and the exterior surface may be textured or optionally laminated with a decorative film. The cover member  23  is comprised of a first flat portion  31  and a second flat portion  32 , the first and second flat portions intersecting at a rounded corner portion  35 . The cover members  23  further includes a first inwardly turned, hooked shaped end portion  33  on the edge of the first flat surface  31 , which hooks around for engagement to the first raised edge portion  27  of the retainer member  21 . Likewise, a second inwardly turned, hooked shaped end portion  34  on the edge of the second flat surface  32  of the cover member  23  hooks around for engagement over the second raised edge portion  28  of the retainer member  21 . Being vinyl, the cover member  23  is capable of deforming a slight amount to bend the two hook shaped end portions  33  and  34  apart from each other to fit over the opposing edges  27  and  28  of the retainer member  21 , and then return to its original shape. Accordingly, the cover member  23  snaps in place and fits snugly over the retainer member  21 . 
     The cover member  23  fits over the retainer member  21  in a spaced apart relation. In other words, when the cover member  23  is assembled onto the retainer member  21 , the interior surface of the cover member  23  is spaced a short distance apart from the outer surface of the retainer member  21 . This provides a narrow gap or buffer zone between the two components. Consequently, in the event a wheeled vehicle strikes the corner guard assembly  20 , the cover member  23  absorbs and dissipates the initial impact. Only if the impact is significant enough will the cover member  23  be propelled towards and strike against the retainer member  21 . 
     The impact load is further dissipated by the design of the cover member  23  and the retainer member  21 , and consequently by the manner in which the inside surface of the cover member strikes the retainer member. Specifically, the inside surface of the rounded corner portion  35  of the cover member  23  defines an inner radius. The co-extruded bumper  30  on the apex of the retainer member  21  is also preferably rounded with an outer radius that corresponds to the inner radius of the corner portion of the cover member. As a result, in the event the cover member  23  is struck with significant force to cause it to strike against the retainer member  21 , the inner radius of the corner portion  35  of the cover member will become engaged against the outer radius of the co-extruded impact bumper  30  on the apex of the retainer member. Because the inner radius of the corner portion of the cover member corresponds to the outer radius of the impact bumper, the surface area of engagement between the two surfaces is maximized, thereby spreading the impact force over the maximum possible area of the flexible PVC material of the impact bumper. 
     Endcaps  24 , preferably fabricated from an injection molded Thermoplastic material preferably of the same decorative color as the cover member  23 , are applied to the upper and lower ends of the corner guard assembly. 
     The corner guard assembly disclosed herein has a very desirable aesthetic appearance. Moreover, it performs in accordance with the highest architectural standards and specifications for institutional type facilities, including standards relating to fire protection and flammability, impact strength, chemical and stain resistance, and installation requirements. With respect to impact strength in particular, the present invention has been found to resist impact forces in excess of 150 ft.-lb. with no visible blemishes appearing on the vinyl cover surface and no deformations in the co-extruded vinyl retainer. 
     Of course, specific structural details disclosed above are not to be interpreted as limiting the scope of the invention, but represented merely as a basis for the claims and for teaching one skilled in the art to employ the present invention in any appropriately detailed structure. Changes may be made in the specific structural details of the particular embodiment disclosed above without departing from the spirit of the invention, especially as defined in the following claims.

Summary:
A corner guard assembly for protecting the corner of a building wall particularly in institutional type facilities from damage due to impacts with wheeled vehicles includes a vinyl retainer base plate, a plurality of fasteners for fastening the base plate to the corner of the building wall, a vinyl cover member assembled over the base plate, and endcaps assembled to the upper and lower ends of the assembly. The novel vinyl base plate further includes a rigid main body portion that is applied over the wall surface at the corner combined with a co-extruded flexible impact bumper at the apex of the main body, the impact forces being absorbed by the impact bumper. The geometry of the cover member matches the geometry of the impact bumper to maximize the surface contact area of the two components to further dissipate the impact forces.