An overhead coiling closure is presented. A repositionable impact bar assembly engages a guide bracket mounted adjacent to the coiling closure when the closure is in a closed position. When in an open position, the impact bar assembly is released from the guide bracket and attaches to the coiling closure to provide repositionable impact protection. As the coiling closure closes the impact bar assembly is once again engaged by the guide bracket.

CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of U.S. Provisional Application No. 61/766,050 filed Feb. 18, 2013 and U.S. Provisional Application No. 61/904,012 filed Nov. 14, 2013. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to impact protection for overhead closures and in particular, to impact protection for an overhead coiling door. 
     BACKGROUND OF THE INVENTION 
     Access openings in warehouse, manufacturing and industrial settings are often secured by overhead (vertically traveling) closures. 
     Rolling steel doors, also referred to as overhead coiling closures, are metal slatted doors which move in a generally vertical path coiling above the opening as the door is opened. Because rolling steel doors have many fewer parts than sectional doors with less risk for damage and inoperability they often make a better solution for facilities that cannot afford opening downtime. 
     An overhead coiling closure is either provided with a powered operator to power the door to an open or closed position or it is manually opened and closed with, for example, a looped chain or crank. A shaft is horizontally mounted above the access opening to wind or unwind the coiling closure while the door sides are maintained within tracks mounted to the building structure on either side of the access opening. The coiling shaft and operator (if present) are usually covered and protected by a hood. 
     When doors are installed in high traffic areas, for example, shipping and receiving areas, the door can be damaged if struck by, for example, a fork lift transporting cargo. This damage can be caused not only by the forklift itself but also by the cargo being trucked by the lift. If the door becomes damaged the coiling closure may become non-operational with resultant access opening downtime. 
     Accordingly, there is still a continuing need for improved door protection designs. The present invention fulfills this need and further provides related advantages. 
     BRIEF SUMMARY OF THE INVENTION 
     In a first embodiment an impact bar assembly is fixedly mounted to an overhead coiling door. 
     In a second embodiment an impact bar assembly is repositionally mounted to an overhead coiling door. 
     One advantage of the present invention is the prevention of damage to the overhead coiling closure obviating the need for repair or replacement. 
     Another advantage is the reduction in access opening downtime due to damage of the overhead coiling closure from impact force strikes. 
     Yet another advantage is the automatic resetting of the impact bar assembly to the protective, starting position removing the need to restrict use of the access opening during a manual reset. 
     Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the present invention. These drawings are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present invention, and together with the description, serve to explain the principles of the present invention. 
         FIG. 1  is a perspective view of the bumper bar mounted to the impact guide bracket assembly. 
         FIG. 2  is an exploded perspective view of the bumper bar and impact guide assembly bracket mounting. 
         FIG. 3  is a top view of the bumper bar mounted to the impact guide bracket assembly. 
         FIG. 4  is a sectional view of the bumper bar mounted to the impact guide bracket assembly taken at A-A of  FIG. 3 . 
         FIG. 5  is an exploded perspective view of the guide block mounted to the stationary bracket. 
         FIG. 6  is an exploded perspective view of a fixedly mounted impact bar assembly with the guide assembly removed. 
         FIG. 7  is a perspective view of a fixedly mounted impact bar assembly with the guide assembly in place. 
         FIG. 8  is an exploded perspective view of a positionally mounted impact bar assembly. 
         FIG. 9  is a perspective view of a positionally mounted impact bar assembly in a partially opened door position. 
         FIG. 10  is a perspective view of a positionally mounted impact bar assembly in a closed door position. 
     
    
    
     Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     As required, detailed embodiments of the present invention are disclosed; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. The figures are not necessary to scale, and some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. Where possible, like reference numerals have been used to refer to like parts in the several alternative figures. 
     Turning now to  FIG. 1 , in an embodiment used with, for example, a rolling steel door, impact bar assembly  2  comprises a bumper bar  4  translationally mounted at each end to an impact guide bracket assembly  6 . Although only one end is shown, it is to be understood that the other end has the same geometry and, therefore, will not be separately described. 
       FIGS. 2-5  more fully show the component parts of the impact guide bracket assembly  6 . A bumper bar engagement member, for example, guide block  8  is mounted to a first leg of a stationary bracket  10 . Mounted to the second leg of the stationary bracket  10  is a resistance element, for example, a spring  12 , mounted via bolt  14  and spring shaft  16 . 
     As shown in  FIGS. 2-4 , a guide block  8  is retained within a hollow end of bumper bar  4  and translationally retains the bumper bar  4  to the impact guide bracket assembly  6 . A bolt  14  passes through the spring shaft  16  which in turn passes through the spring  12  and is received through bumper bar orifice  23 . A thrust plate  18  and retaining plate  20  are mounted outside and within the hollow end of the bumper bar  4 , respectively, to translationally fix the bumper bar  4  to the stationary bracket  10 . This permits an impact force directed against the bumper bar  4  to be dissipated by the spring  12  which subsequently returns the bumper bar  4  to its starting position, determined by the guide block  8 . 
     The impact force is ultimately translated to the guide assembly  44  to relieve the impact force from the door curtain itself. The stationary bracket  10  is positioned such that the spring  12  is effectively located over the guide assembly  44  to protect the rolling steel door  26  throughout the opening and closing range of motion. 
     The impact bar assembly  2  may be fixedly mounted to the rolling steel door  26  as shown in  FIGS. 6 and 7 , or it may be repositionally mounted as shown in  FIGS. 8-10  described in detail below. 
     Turning now to  FIGS. 6 and 7 , the impact bar assembly  2  is fixedly mounted to the rolling steel door  26 , for example, at each end of the rolling steel door bottom bar  28  via bolts  30  which pass through the second leg of the stationary bracket  10 , a bottom bar adapter  32 , the bottom bar  28 , retaining plate  34 , and flat washer  36  to engage nut  38 . 
       FIG. 6  is drawn with the guide assembly  44  of  FIG. 7  removed for clarity. The bearing assembly  40  is mounted to the bottom bar  28  with button head cap screws  42 . The bearings counteract the moment created by the impact bar assembly  2  when the door  26  is in motion and reduce friction between the bottom bar  28  and the guide assembly  44 . An impact force is always absorbed by the spring  12  and transferred through the stationary bracket  10  and into the guide assemblies  44 . 
     Turning now to  FIGS. 8-10  which show the repositional mounting of impact bar assembly  2 , an impact bar assembly retaining element, for example, a guide bracket  46  is mounted at each side of the rolling steel door  26 , for example, to each guide assembly  44  at a user determined height. Described in detail below, the location of the guide brackets  46  permits retention of the impact bar assembly  2  at a closed door user defined location different from that of the fixedly positioned bottom bar  28  location shown in  FIGS. 6 and 7 . 
     A bottom bar retaining member, for example, a bottom bar bracket assembly  48  is mounted to the rolling steel door  26 , for example, mounted at each side of the bottom bar  28 . Bottom bar bracket assembly  48  comprises a first  50  and second  52  leg with effective spacing therebetween to releasably engage the impact guide bracket assembly  6 . 
     In use, with the rolling steel door  26  fully closed ( FIG. 10 ), the impact bar assembly  2  is releasably mounted to the guide brackets  46  by releasably inserting the impact guide bracket assembly  6  into the guide brackets  46 . As the rolling steel door  26  is opened the bottom bar bracket assemblies  48  releasably engage the impact guide bracket assemblies  6  to lift the impact bar assembly  2  off the guide brackets  46  thereby raising the impact bar assembly  2  upward with the bottom bar  28  to allow passage through the door opening while continuing to provide rolling steel door  26  impact protection. 
     When the rolling steel door  26  is closed, upon reaching the guide brackets  46 , the impact guide bracket assemblies  6  re-engage the guide brackets  46  and the impact bar assembly  2  is released from the bottom bar bracket assemblies  48  and is once again maintained in the guide brackets  46  as the rolling steel door  26  continues to close. 
     Optionally, an impact bar retainer, for example, an extension spring assembly  54  is employed to prevent the impact bar assembly  2  from lifting off the guide brackets  46  when not being engaged by the bottom bar bracket assemblies  48 . The extension spring assembly  54  ( FIG. 9 ) comprises, for example, a plurality of fasteners, for example, eye bolts  56  mounted to the bottom bar  28  ( FIG. 8 ). Passing through the eye bolts  56  are steel cables  58  fixed at one end to an extension spring  60  with each cable other end engaging an impact guide bracket assembly  6  ( FIG. 9 ). As shown in  FIG. 10 , when the rolling steel door  24  is closed and the impact bar assembly  2  is engaged within the guide brackets  46 , the steel cables  58  are deflected and in combination with the extension spring  60  maintain a retaining pressure on the impact guide bracket assemblies  6  to help retain the impact bar assembly  2  within the guide brackets  46 . 
     As the rolling steel door  26  opens and the impact bar assembly  2  is lifted off the guide brackets  46 , the extension spring  60  in its retracted position pulls the cables  58  towards the center of the rolling steel door  26  to help retain the impact bar assembly  2  within the bottom bar bracket assemblies  48 . 
     Although the present invention has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present invention is capable of other variations and modifications within its scope. These examples and embodiments are intended as typical of, rather than in any way limiting on, the scope of the present invention as presented in the appended claims.