Patent Document

TECHNICAL FIELD 
     In general, the present invention relates to movable barriers, such as garage doors. More particularly, the present invention relates a roller guard for such movable barriers to prevent objects, including body parts, from being pinched or crushed. More specifically the present invention relates to a roller guard for doors having door mounted rollers movable in tracks, wherein the roller guard prevents objects from being caught between the rollers and the track. 
     BACKGROUND OF THE INVENTION 
     Movable barriers, including garage doors, raise entrapment and entanglement concerns. In particular, open spaces in and around the door and close to the moving parts of the door may allow an object to enter this open space and be pinched or crushed by the moving parts of the door. In the past, objects within the garage including tool handles, clothing, and body parts, such as hands or fingers have been pinched or crushed by the door. Such dangers are a safety concern to users and may interfere with operation of the door. To provide safer door systems, attempts have been made to prevent such entrapment Of particular concern is the possibility of a finger or hand being placed within a track section where it might be crushed or pinched by a roller traversing the track. One existing roller shield design is used in connection with a sectional door in an attempt to alleviate the aforementioned danger. The sectional door includes a plurality of door sections hinged together in edge-to-edge relationship. Support rollers are attached to each door section and confined within a pair of support tracks located on either lateral side of the door. To prevent entrapment between the roller and the track, a circular or rectangular roller shield is mounted on the axle of each support roller outside the track. The shield is placed proximate to the track to prevent fingers from entering the track near the support rollers. In addition to the roller shields, protective shield wings are provided to enclose the support track and prevent objects from interfering with the roller as well as to provide transport guidance where the sections meet. The outer edge of the shield is blunted or protected to prevent harm during operation. Similarly, the edge of the support track includes a folded single hem used to prevent fingers from being cut as they are brushed aside by the roller shield. 
     Designs with these features have certain disadvantages. For example, because the shields are positioned outside the track they may interfere with other track components. Further, the external shields typically must physically contact the track or be in such close proximity as to intermittently contact the track in order to adequately protect a user from the rollers. When contacting, unwanted friction is created, making it continuously or intermittently more difficult to open and close the sectional door and creating substantial noise. 
     Therefore, there exists a need in the art to provide a roller guard which provides pinching and crushing protection but does not suffer the normal disadvantages. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a guard for the roller of a movable barrier which is positioned inside the track of a movable door system. It is a further object of the present invention to provide a guard for a movable door system which does not interfere with door components outside the track assembly. Another object of the invention is to provide such a roller guard that can be used on the bottom roller of a sectional door without affecting the operation or total closing of the door. 
     It is an additional object of the present invention to provide a roller guard for a movable door system, where the guard is adapted to minimize frictional contact with track components during movement of the door. It is yet another object of the present invention to provide such a guard for a movable door system which is a single molded piece that encloses the roller while having the operative components for shielding substantially entirely within the tracks. It is a still further object of the invention to provide such a roller guard that may be structurally adapted to operate with a variety of configurations of track assemblies and rollers employed in the industry and does not require track having a hemmed edge. 
     These and other objects of the present invention, as well as the advantages thereof over existing prior art guards, which will become apparent from the description to follow, are accomplished by the improvements hereinafter described and claimed. 
     In general, the present invention contemplates a door system having, a door, a plurality of track sections having a cross-section defining an interior track area that is accessible though an opening therein, a roller received in the interior track area and coupled to a shaft that is operatively interconnected with the door, and a guard carried by the shaft and at least partially enclosing the roller, wherein the guard includes a shield wall that is positioned within the interior track area and at least partially obstructs the opening in the area of the roller. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a rear perspective view of a door system including guide tracks attached to a framework that defines the door opening and rollers on the door engaging the track with guards according to the concepts of the present invention; 
         FIG. 2  is an enlarged fragmentary perspective view of the portion of  FIG. 1  indicated thereon, showing additional details of the roller guard when positioned along the length of the vertical track section of the door; 
         FIG. 3  is an enlarged fragmentary perspective view taken in the manner of  FIG. 2 , with a portion of the vertical track section cut away to show details of the interrelation between the track, a roller and the roller guard; 
         FIG. 4  is a top plan view of a roller guard and track section of the door system of  FIG. 1 ; 
         FIG. 5  is a side elevational view of a roller guard taken substantially along line  5 - 5  of  FIG. 4 ; 
         FIG. 5A  is an elevational view of a roller, track and a roller guard with portions shown in section taken substantially along the line  5 A- 5 A of  FIG. 2 ; 
         FIG. 6  is an enlarged isometric view of the roller guard according to the concepts of the present invention showing particularly the interior configuration thereof; 
         FIG. 7  is an enlarged isometric view of the roller guard according to the concepts of the present invention showing particularly the exterior configuration thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A roller guard according to the concepts of the present invention, generally indicated by the numeral  60  in the accompanying drawings, is used in connection with a movable barrier, such as a garage door system, generally indicated by the numeral  10  in the accompanying drawings. Since the roller guard  60  may be used in connection with a number of different door systems  10 , only general reference will be made to the door system components other than those directly involved with the roller guard  60 . 
     In general, door system  10  ( FIG. 1 ) is mounted within an opening defined by a framework having a pair of spaced vertical jambs  11  connected by a laterally extending header  12  near the upper vertical extremity of the jambs  11 . A door D resides within the opening and is moveable on a pair of guide track assemblies, generally indicated by the numeral  15 , that guide the door D between a generally vertical closed position and a generally horizontal open position (not shown). 
     To offset the weight of the door D, as it is operated on guide track assemblies  15 , a counterbalance assembly, generally indicated by the numeral  20 , may be used in connection with the door D in a manner well known in the art. Guide track assemblies  15  include a generally vertical track section  16  and a generally horizontal track section  17  which are joined by a curved transition track section  18 . In the track assemblies  15  shown, a second horizontal track section  19  is disposed above the horizontal track section  17 . 
     Referring to  FIGS. 1-4 , track sections  16 - 20  receive rollers  25  of door D in arrangements known to persons skilled in the art. Referring particularly to  FIG. 4 , guide track assemblies  15  in cross section are of a generally J-shaped configuration, having an upstanding leg  22  with a U-shaped curve  23  proximate to one end for receiving the running surface  24  of a roller  25 , which is mounted on the end of a shaft  26 . The other end of the upstanding leg  22  has a lateral leg  27  that restrains excessive movement of the roller  25  from the U-shaped curve  23 . Track assembles  15  are coupled to standoff brackets  28  attached to the vertical track sections  16  by a plurality of bolts  29  having heads  30  which located on the interior of track  15 . While the present embodiment depicts a single vertical track design, it should be appreciated that the invention described herein is equally applicable to dual vertical track designs or any other roller track arrangements known in the art. 
     As best shown in  FIGS. 2 and 3 , each shaft  26  may be secured to door D at a hinge, generally indicated by the numeral  31 . Hinge  31  includes a first leaf  32  and a second leaf  33  pivotally attached to first leaf  32 . First leaf  32  is mounted flush on a door panel d′ and similarly secured thereto by a plurality of bolts  34 . Second leaf  33  is mounted flush on an adjoining door panel d″ and secured by a plurality of bolts  35 . First and second leaves  32  and  33  are each secured to a pin  36  which allows relative pivotal movement of door panels d′ and d″. Second leaf  33  is provided with a pair of spaced flanges  37  which project away from door panel d″. Each flange  37  is provided with an aperture  38 . Secured between apertures  38 , which are axially aligned, is a roller carrier  39  which is a hollow cylindrical tube adapted to slidably and removably receive a shaft  26  which mounts a roller  25 . Roller  25  is provided with a bearing (not shown) which allows for free rotation relative to shaft  26 . Shaft  26  also is free to move axially within roller carrier  39  during operation of door D. 
     Referring to  FIGS. 4 and 5A , a first circumferential boss  40  may be provided on shaft  26  and has a radius greater than that of shaft  26 . A second circumferential boss  41  having the same radius as the first boss  40  may further be provided and positioned between roller  25  and first boss  40 . It should be appreciated that, while the present embodiment includes a pair of bosses, the invention described herein is applicable to roller and shaft designs which do not include bosses and other roller and shaft arrangements known in the art. 
     As best shown in  FIG. 4 , upstanding leg  22 , U-shaped curve  23  and lateral leg  27  define an interior track cavity  50 . Further, an opening  51  is defined between the lateral leg  27  and U-shaped curve  23  of track  15 . As will be appreciated, objects entering opening  51  may interfere with the operation of the door D or be damaged as rollers  25  traverse track  15 . Of particular concern is the entrapment of a hand or fingers within interior track cavity  50  during door operation. To prevent a foreign object, hand or finger from entering opening  51  proximate a roller  25 , the roller guard, according to the concepts of the present invention, and, generally indicated by the numeral  60 , is provided. 
     As best shown in  FIGS. 2-4 , roller guard  60  is carried on shaft  26  and at least partially encompasses roller  25 , so as to reduce the likelihood of crushing a foreign object or finger between tracks  15  and a roller  25 . As shown, roller guard  60  is a single piece body  61  which, when installed, resides entirely within interior track cavity  50 . Body  61  includes a shield wall  62  which, as seen in  FIG. 5A , partially covers opening  51  when installed. As best seen in  FIG. 7 , shield wall  62  may be generally rectangular defining a pair of longitudinal edges  63   a  and  63   b  and a pair of lateral edges  64  wherein longitudinal edges  63   a  and  63   b  are joined by lateral edges  64 . 
     When roller shield  60  is mounted in tracks  15 , shield wall  62  is generally parallel to upstanding leg  22 , as is evident in  FIG. 4 , and may be positioned within and obstruct at least a portion of opening  51 . Referring to  FIGS. 5-7 , an annular projection  65  may extend axially from shield wall  62  towards hinge  31 . Extending through both shield wall  62  and annular projection  65  is a bore  66  which is adapted to receive circumferential bosses  40  and  41  therein. The diameter of bore  66  may be sized to provide a press fit when the roller guard  60  is installed over circumferential bosses  40  and  41 . A circumferential flange  67  is provided at the end of annular projection  65  extending radially inward therefrom. 
     A plurality of circumferentially spaced tabs  68  are provided which extend radially inward from flange  67 . Each tab  68  includes a contact surface  69  which may be positioned to engage shaft  26 . Flange  67  and tabs  68  are sized so that when assembled, contact surfaces  69  of tabs  68  grip shaft  26 . In this manner, the roller guard  60  is thereby restrained both axially and rotationally relative to shaft  26 . 
     Referring to  FIGS. 4-7 , a pair of opposed sidewalls  70  project orthogonally from shield wall  62  at lateral edges  64  and a top wall  71  projects generally orthogonally from shield wall  62  at longitudinal edge  63   a . Top wall  71  includes a pair of spaced edges  72  which extend towards shield wall  62  and are joined by a curved edge  73 . Edges  72  and  73  define a groove  74  which allows a portion of roller  25  to project therethrough. In other words, when installed, a portion of roller  25  extends beyond top wall  71  to enable contact with lateral leg  27  of track  15  as best seen in  FIGS. 4 ,  5  and  5 A. Side walls  70  and top walls  71  intersect at edges  75 . Edge  75  is radiused in order to prevent jamming of roller guard  60  within tract  15  as will be discussed later. In one or more preferred embodiments depending upon curvature of track  15  and other dimensions, the radius of edge  75  is from between 0.125 and 0.375 inches. In a particularly preferred embodiment the radius of edge  75  is 0.250 inches. 
     Body  61  is further provided with a pair of fingers  80  which are positioned at the bottom of roller guard  60  proximate to the U-shaped curve  23  in track  15  as seen in  FIGS. 4 ,  5  and  5 A. Fingers  80  project from side walls  60  on either side of roller  25 . Fingers  80  are adapted to further prevent objects from being entrapped between roller  25  and track  15 , while also preventing jamming as rollers  25  traverse track  15 . Referring to  FIGS. 4 and 5 , fingers  80  include a beveled surface  81  which is disposed at an angle             from side walls  70 . In one or more preferred embodiments, depending upon the curvature of track  15  and other dimensions, the angle           is between 45 and 70 degrees. In a particularly preferred embodiment the angle           is 60 degrees.
     As seen in  FIG. 4 , fingers  80  in a direction axially of roller  25  include a first angled surface  82  and a second opposed angled surface  83  which are joined by a curved surface  84  in an open U-shaped configuration. First angled surface  82  is disposed at an angle α from shield wall  62 . Second angled surface  83  is disposed at an angle β from an edge  85  defined by side wall  70 . The angle α of first angled surface  82  is chosen to reduce contact with track  15 . In one embodiment the angle α may be chosen so that it is generally parallel to the portion of track  15  which faces first angled surface  82  or so that running surface  24  of roller  25  engages the proximate surface of U-shaped curve  23  before angled surface  82  can engage the U-shaped curve  23 . In another embodiment the angle α may be about 45°. Similarly, the angle β of second angled surface  83  is chosen to reduce contact with track  15 . In one embodiment the angle β may be chosen so that it is generally parallel to the portion of track  15  which faces second angled surface  83  or so that running surface  24  of roller  25  engages the proximate surface of U-shaped curve  23  before angled surface  83  can engage the U-shaped curve  23 . In another embodiment the angle β may be about 25°. Fingers  80  and shield wall  62  define a bottom groove  86  extending between fingers  80  which is adapted to allow a portion of roller  25  to extend therethrough. When installed, a portion of roller  25  extends beyond fingers  80  to provide contact with the U-shaped curve  23  of track  15 . 
     As seen in  FIG. 6 , shield wall  62 , side walls  70 , top wall  71  and fingers  80  define a chamber  87  which receives roller  25  therein. Chamber  87  includes an annular surface  88  which projects radially outward from bore  66 . A pair of roller surfaces  89  circumferentially surround roller  25  and terminate at edges  72  and fingers  80 . Positioned between annular surface  88  and roller surface  89  is a curved surface  90 , which smoothly connects the aforementioned surfaces. As is evident from  FIG. 5 , roller  25  resides in chamber  87  and, to that end, roller surfaces  89  define a diameter which is greater than that of roller  25  to allow free rotation therein. 
     Referring now to  FIGS. 2-4 , it can be seen that roller guard  60  is located axially of shaft  26 , and when positioned over roller  25 , will prevent objects from being crushed between track  15  and roller  25 . When installed, roller guard  60  in cooperation with track  15  encloses roller  25 , leaving no substantial part of roller  25  exposed to external objects. Further, as rollers  25  traverse track  15 , side walls  70 , edge  75  and beveled surface  81  push any intervening object harmlessly in front of guard  60 . 
     As is evident from  FIGS. 2 and 3 , the body  61  of roller guard  60  resides within track  15 . Particularly, shield wall  62 , side walls  70 , top wall  71 , and fingers  80  are all positioned within the interior track cavity  50  defined by track assembly  15 . Only annular projection  65  extends beyond opening  51 , closely encircling bosses  40  and  41 . Friction is minimized because no shielding surfaces remain in continuous contact with the track assembly. Additionally, roller guard  60  will not interfere with any external track system components. Further, due to its compact design, guard  60  can be installed on any of the rollers  25 , including those located on the lowermost edge of door D. 
     It is to be appreciated that the guard  60  not only protects users from injury but does not encumber door movement. Therefore, the roller guard  60  of the present invention produces little friction and is not prone to jamming. Jamming is particularly a concern as roller guard  60  traverses a transitional track section  18 , due to the curved orientation thereof. It should be appreciated that components of transitional track section  18  embody different radii of curvature. 
     Specifically, the radius of curvature of lateral leg  27  is larger than that of curved portion  23 . In order to promote smooth operation, radiused edges  75  and beveled surface,  81  are provided. As discussed above, edge  75  is provided with a radius to reduce contact with lateral leg  27  while traversing track section  18 . 
     Further, beveled edge  81  is disposed at angle             which reduces contact with curved section  23 . While it is desired that the roller guard  60  contact the track assembly  15  as little as possible, it should be evident, that due to the orientation of the roller guard  60  within track assembly  15 , some contact is necessary. Particularly, while traversing track section  18 , beveled surface edge  81  and edges  75  intermittently contact track assembly  15  in order to progressively reorient the roller guard  60  therein. Such contact is only intermittent and edges  75  and  81  are adapted to reduce friction when such contact occurs. In this manner, guard  60  does not interfere with roller movement or unduly create frictional forces.
     Thus, it should be evident that the roller guard for a movable barrier disclosed herein carries out one or more of the objects of the present invention set forth above and otherwise constitute an advantageous contribution to the art. As will be apparent to persons skilled in the art, modifications can be made to the preferred embodiments disclosed herein without departing from the spirit of the invention, the scope of the invention herein being limited solely by the scope of the attached claims.

Technology Category: e