Abstract:
A guard assembly is used near a doorway with an overhead door on a platform having at least one post mounted adjacent the doorway. The assembly preferably comprises a barrier adapted to extend across the doorway and having at least one coupling which is adapted to connect to a respective post to allow the barrier to block the doorway; and a bracket adapted to facilitate connection and disconnection between the barrier and the overhead door. Such an assembly allows the barrier to block the doorway whether connected to or disconnected from the door and to move with the door as the door opens and closes.

Description:
FIELD OF THE INVENTION 
   The invention relates to the field of overhead doors, and, more particularly, to overhead doors used on raised loading docks. 
   BACKGROUND OF THE INVENTION 
   Typically loading docks include a raised dock for the loading and unloading of materials which often come in large quantities and are carried by wooden pallets. Most docks have doorways with overhead doors that provide access to a garage or similar type of building. These overhead doors are similar to garage doors found in most domestic homes and may be operated manually or automatically. 
   In many cases, a dock leveler is mounted in a pit in the loading dock in front of the doorway and operation of the dock leveler will serve to bridge the gap between the loading dock and a truck parked in front of the dock so that personnel and material handling equipment, such as a forklift truck, can conveniently move between the loading dock and the truck bed. 
   During a loading operation the truck body will enclose the open doorway in the dock. Often when a loading dock operation is not taking place, it is desired to maintain the overhead door in an open position to provide increased ventilation or light in the building or to vent smoke, fumes or odors from the building. 
   While there are typically a pair of posts mounted on opposite sides of the doorway to provide a barricade that will protect a forklift truck from damaging the wall or door track at one or both sides of the door, there is a possibility that a forklift truck maneuvering on the dock may accidentally back through the open doorway and fall off the loading dock to the driveway, thus causing possible injury to personnel and/or damage to equipment. 
   Attempts to prevent such damage have heretofore included the use of a second door mounted inside of the outer door and constructed of metal mesh to allow the passage of light and air. However, such additional security doors have required use of an additional overhead track system and prohibit passage of materials and people. 
   Other attempts have including placing barriers in front of the doorway. However, such barriers must typically be moved by an operator and then must be stored in an non-traffic area. 
   Thus, there is a need in the field for a loading dock guard assembly which is readily installed on pre-existing doors and does not require additional tracks, motors or separate operation from the overhead door. 
   In addition, there is a need for a loading dock guard assembly which allows passage of people or things, such as packages, while preventing passage of vehicles. 
   Also, there is a need for a loading dock guard assembly which may be moved into and out of blocking position by an overhead door, and be disconnected from such door to remain in blocking position while the door is open or closed. 
   A guard assembly for use with overhead doors platforms which addresses the problems of known devices would be an important advance in the art. 
   OBJECTS OF THE INVENTION 
   It is an object of the invention to provide a guard assembly for use with an overhead door which can be installed on existing doors. 
   Another object of the invention is to provide a guard assembly for use with an overhead door which includes a barrier that can be connected to an overhead door to be raised into an open position and lowered into a blocking position. 
   Another object of the invention is to provide a guard assembly for use with an overhead door which includes a barrier that can be disconnected from a door to block the doorway while the door is opened. 
   Another object of the invention is to provide a guard assembly for use with an overhead door which includes a barrier that connects to at least one post located adjacent the doorway to block the doorway. 
   Another object of the invention is to provide a guard assembly for use with an overhead door which includes a guard rail and, most preferably, an OSHA compliant hand rail. 
   Another object of the invention is to provide a guard assembly for use with an overhead door which includes a barrier pivotably connected to the door to allow movement with the door to an open position. 
   Another object of the invention is to provide a guard assembly for use with an overhead door to block a vehicle from driving off of a dock when the door is open. 
   Yet another object of the invention is to provide a guard assembly for use with an overhead door which includes barrier means adapted to block the doorway when disconnected from the door whether open or closed; block the doorway when connected to the door while the door is closed; and, when connected to the door, move with the door as the door opens so that the barrier means does not block the doorway. 
   Still another object of the invention is to provide an efficient and economical way to block an overhead door doorway with a movable barrier. 
   How these and other objects are accomplished will become apparent from the following descriptions and drawings herein. 
   SUMMARY OF THE INVENTION 
   This invention is a guard assembly for use near a doorway on a platform. The invention represents a significant advance over the state of the art by providing novel elements to provide broader use, retrofit capability, and safety to loading docks with overhead doors. 
   The guard assembly comprises: a barrier adapted to extend across and block the doorway, the barrier having at least one coupling adapted to connect to a respective post and to be preferably supported by the post; and a bracket adapted to facilitate connection and disconnection between the barrier and the overhead door. Such an assembly allows the barrier to block the doorway whether connected to or disconnected from the door. In addition, the barrier, when connected to the door, is adapted to move with the door as the door opens and closes. 
   In certain preferred embodiments, the bracket is fixed to the barrier and is adapted for connection with and disconnection from the door. In these embodiments the bracket and door are preferably adapted for connection and disconnection by a pin. In other embodiments, the bracket is fixed to the door and is adapted for connection and disconnection from the barrier. In these embodiments the bracket and barrier are preferably adapted for connection and disconnection by a pin. Therefore, in most preferred embodiments, the bracket is fixed to one of the barrier and the door and is adapted for connection with and disconnection from the other of the barrier and the door, such connection and disconnection preferably being performed by a pin. 
   Connection and disconnection are preferably performed in “one motion,” i.e., the door and bracket or barrier and bracket are automatically aligned and the operator simply needs to move the pin along an axis to connect or disconnect the bracket from the other object. “One-motion” connection/disconnection defines such an action in which the operator need only move the pin in the desired direction, no other actions are necessary to complete connection/disconnection since the guard assembly automatically positions the door, bracket and barrier into position for connection/disconnection after installation. 
   The platform preferably has two posts mounted on opposite sides of the doorway and the barrier preferably has two couplings which are each adapted to connect to a respective post. Each coupling is preferably a sleeve which is adapted to receive the respective post. In certain embodiments, the couplings are guard couplings and the assembly further comprises upper couplings which are also adapted to connect to respective posts. 
   The barrier may also include a guard rail extending between the couplings, a pair of uprights extending from the guard rail to distal ends, and a hand rail extending between the distal ends of the uprights. In certain variations of such embodiments, the bracket preferably includes first and second brackets with each bracket being pivotably connected to the barrier and connected to a respective upright by a tensioning element. In other variations of such embodiments, the bracket includes first and second brackets with each bracket being pivotably connected to the door and further connected to the door by a tensioning element. 
   In certain embodiments, the door is movable along a track and the barrier includes a guard rail, a pair of uprights extending from the guard rail to a distal end, and a hand rail extending between the distal ends of the uprights while the bracket includes first and second brackets which provide pivotable connection between the barrier and the door and, optionally, are connected to a respective upright or to the door by a tensioning element. In such embodiments, the distal ends of the uprights are adapted to contact a sloping portion of the track and cause both the barrier to pivot with respect to the door and the tensioning element to extend, thereby allowing the distal ends of the uprights to move substantially horizontally as the guard rail moves substantially vertically when the door and barrier are connected and the door opens. Each bracket preferably provides pivotable connection between the barrier and the door such that the barrier is adapted to pivot with respect to the door as the distal ends of the uprights move substantially horizontally and the guard rail moves substantially vertically. 
   In other embodiments, the guard assembly is intended for use with doors which run on tracks that do not include a sloping or substantially horizontal portion, i.e., they extend substantially vertically above the doorway. In such embodiments, the barrier need not be pivotable with respect to the door. Therefore, in such embodiments, the bracket is mounted to one of the door and barrier and is adapted for connection to the other of the door and barrier, with neither the mount nor the connection providing for pivotability. 
   In another description of the invention, the guard assembly for use near a doorway on a platform comprises: barrier means adapted to extend across the doorway and having at least one coupling means adapted to connect to a respective post; and connection means adapted to facilitate connection and disconnection between the barrier means and the overhead door. Thus, the barrier means is adapted to block the doorway when disconnected from the door, block the doorway when connected to the door while the door is closed, and move with the door when connected to the door as the door opens so that the barrier means does not block the doorway. When connected to the door, the barrier means is preferably adapted to move with the door as the door closes and to connect to the post to block the doorway. 
   The connection means is preferably pivotably mounted to one of the barrier means and the door, a bracket pivotably mounted with respect to one of the door and barrier means, and latching means adapted to connect to and disconnect from the other of the door and barrier means. In certain embodiments, the connection means may include a door plate mounted with respect to the door, a hinge plate pivotably connected to the barrier means and a latching means to connect the door plate and hinge plate. In certain other embodiments, the connection means may include a door plate mounted with respect to the door, a hinge plate pivotably connected to the door plate and a latching means to connect the hinge plate to the barrier means. In such embodiments, the barrier means preferably includes a receiving bracket for connection to the hinge plate. 
   In another description of the invention, the guard assembly, in combination with an overhead door in a doorway and a pair of posts mounted on opposite sides of the doorway, comprises: a barrier having two ends with a coupling at each end is adapted to extend across the doorway with each coupling adapted to connect to a respective post; and a bracket adapted to facilitate connection and disconnection between the barrier and the overhead door. In such an embodiment, the barrier is adapted to block the doorway whether connected to or disconnected from the door, and the barrier, when connected to the door, is adapted to move with the door as the door opens and closes. 
   In certain embodiments, each post includes a truss which joins the respective post at a shoulder which supports the couplings. It is preferred that the couplings be adapted to contact the respective shoulder when the door is closed and the bracket connects the door and barrier. In certain embodiments, the door preferably includes a plate and the couplings are adapted to contact the respective shoulder when the plate and bracket are aligned to allow a pin to pass therethrough to pivotably connect the door and the barrier. 
   In other certain embodiments, the barrier includes a guard rail extending between the couplings, a pair of uprights extending from the guard rail to a distal end, and a hand rail extending between the distal ends of the uprights; the bracket includes first and second brackets which are each pivotably connected to the barrier and connected to a respective upright by a tensioning element; and the overhead door includes pivotably connected panels and moves along a track having substantially vertical and substantially sloping portions. In such embodiments, the distal ends of the uprights are adapted to contact the substantially sloping portion of the track to cause the barrier to pivot with respect to the brackets and to cause the tensioning element to extend to allow the distal ends of the uprights to move substantially horizontally as the guard rail moves substantially vertically when the barrier is connected to the door as the door opens. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate preferred embodiments which include the above-noted characteristics and features of the invention. The invention will be readily understood from the descriptions and from the drawings, in which: 
       FIG. 1  is a front view of the guard assembly in accordance with the invention. 
       FIG. 2  overhead view of a barrier in connection with the posts and door in accordance with the invention. 
       FIG. 3  is an enlarged view of the connection between the barrier and a post and the door in accordance with the invention. 
       FIGS. 4   a  and  4   b  are side views of a preferred guard assembly shown disconnected and connected to a door in accordance with the invention. 
       FIG. 5  is a plan view of a pin and preferred bracket components in accordance with the invention. 
       FIG. 6  is a side view of a preferred barrier connected to the door and showing the movement of the barrier as the door is opened and/or closed in accordance with the invention. 
       FIG. 7  is a side view of a preferred guard assembly shown connected to a door in accordance with the invention. 
       FIG. 8  is a side view of a preferred guard assembly shown disconnected from a door in accordance with the invention. 
       FIG. 9  is a side view of a preferred guard assembly shown connected to a door with the door connected to a post in accordance with the invention. 
       FIG. 10  is an enlarged view of a preferred bracket showing the pivoting motion of the bracket in dashed lines in accordance with the invention. 
       FIG. 11  is a side view of a preferred guard assembly connected to a door and showing the barrier pivoting with respect to the door as the door is opened and/or closed in accordance with the invention. 
       FIG. 12  is an enlarged view of a preferred coupling in accordance with the invention. 
       FIG. 13  is perspective view of the preferred coupling of  FIG. 12  including connection means for connecting the barrier to the bracket and shown disconnected from the bracket in accordance with the invention. 
       FIG. 14  is perspective view of the preferred coupling of  FIG. 13  shown connected to the bracket in accordance with the invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1 and 2 , details of the guard assembly  10  for use near a doorway  102  on a platform  110  will be set forth. The guard assembly  10  includes a barrier  20  which can be connected to a door  100  and coupled to at least one post  120  near the doorway  102 . The posts  120  are preferably mounted to the platform  110  near doorway  102  and equidistant from wall  106  and may be supported by at least one truss  122 . Trusses  122  preferably join the posts to form shoulders  124  which can support barrier  20  when barrier  20  and posts  120  are coupled. 
   Barrier  20  includes a guard rail  23  and preferably has couplings  30  at each end  21 , 22  to couple with posts  120 . Couplings  30  are preferably sleeves which are formed to slide around posts  120  such that each post  120  is received within a coupling  30 . In certain embodiments, uprights  24  extend substantially vertically from barrier  20  and a hand rail  26  preferably extends between the distal ends  25  of uprights  24 . Also connected with respect to uprights  24  are upper couplings  32  which, like guard coupling  31 , are sleeves which are dimensioned to receive posts  120  therein. 
   Hand rail  26  preferably includes a roller  27  at each end to contact track  130  to which door  100  is mounted. Hand rail  26  is preferably compliant with work environment requirements pertaining to railings such as OSHA 1910.23 which requires that certain types, sizes and arrangements of railing construction have a smooth-surfaced top rail at a height above floor, platform, runway or ramp level of 42 inches nominal, have a strength to withstand at least the minimum requirement of 200 pounds top rail pressure, and include protection between the top rail and the floor, platform, runway, ramp or stair treads equivalent to at least that afforded by a standard intermediate rail. 
   Barrier  20  can be connected to door  100  through use of bracket  40 . Preferably first and second brackets  41 , 42  interconnect door  100  and each end  21 , 22  of barrier  20 . In order to facilitate connection and disconnection between barrier  20  and door  100 , at least one door plate  44  is mounted on door  100 . Each plate  44  includes a channel  55  which receives a pin  45 . Channel  55  is preferably designed to align with a hole  56  in bracket  40  when door  100  is closed and barrier  20  is coupled to posts  120  and rests on shoulders  124 . Pin  45  can then slide through hole  56  to connect barrier  20  and door  100 .  FIG. 3  offers an enlarged view of the right side of FIG.  2 . As shown, pin  45  is in the locked position and passes through bracket  40  and raised walls  52 . 
     FIG. 5  shows door plate  44  in more detail. Plate  44  includes two raised walls  52  which form a groove  54  which is formed to snugly receive bracket  40 . When hole  56  in bracket  40  is aligned with channel  55 , pin  45  can be moved along channel  55  through hole  56  in bracket  40 . Pin  45  is then engaged by raised walls  52  and bracket  40  and interconnects door  100  and barrier  20 . This locked position is shown in FIG.  5 . To facilitate movement of pin  45  into and out of the hole in bracket  40  there is provided handle  51  which is connected to pin  45  within housing  53 . As is understood, handle  51  can be moved in a pivoting motion to cause pin  45  to slide along channel  55  into and out of groove  54 . 
     FIGS. 4   a  and  4   b  are side views of the barrier  20 , bracket,  40  and door  100  and show the preferred version of door  100  as having pivotably connected door panels  104 . As can be seen, door plate  44  includes channel  55  which is defined by raised walls  52 . When door is closed, channel  55  is aligned with hole  56  in hinge plate  46  which is a component of bracket  40 . 
   Hinge plate  46  includes an arm  47  which extends away from door  100 . Arm  47  is pivotably connected to bracket mount  48  at pivot  49 , which may of a pin and channel construction. Bracket mount  48  is fixed to barrier  20  such that barrier  20  may pivot about pivot  49  in relation to hinge plate  46 . Hinge plate  46  also includes an upper aperture  57  to receive a tensioning element  43  which may be a spring or any other device which provides tension between hinge plate  46  and barrier  20 . Tensioning element  43  is connected to barrier  20  by catch  58 . Tensioning element  43 , arm  47  and mount  48  keep hinge plate  46  in proper orientation with respect to barrier  20  and door  100  when door is not positioned adjacent barrier  20  (as seen in  FIG. 4   a ). 
     FIG. 6  shows barrier  20  at two positions during upward movement with door  100 . In the lower position door panel  104  is traveling along a substantially vertical portion  132  of track  130 . As door panel moves upward, tensioning elements  43 , arms  47  and mounts  48  keep uprights  24  substantially vertical until rollers  27  contact sloping portion  134  of track  130 . Then rollers  27  roll along track  130  and tensioning element  43  allows barrier  20  to pivot about pivot  49 . When door panel  104  moves downward, tensioning element  43  pulls uprights  24  such that they keep contact with track  130  and barrier  20  pivots back to its original position. In this way, barrier  20  can be moved into and out of the blocking position in which it extends across doorway  102 . 
   During the initial installation of guard assembly  10  on a door  100 , barrier  20  is positioned across doorway  102  and coupled to pre-existing posts  120  or posts  120  installed along with the assembly  10 . When barrier  20  is properly positioned, door plates may be mounted to the door  100  along a door panel  104  which is at the same height as barrier  20  such that each channel  55  is aligned with each hole  56 . Barrier  20  may remain in this blocking position while door  100  is opened or closed. To remove barrier  20  from doorway  104 , channels  55  and holes  56  are aligned and pins  45  are passed through each pair of channels and holes to connect barrier  20  to door  100 . Then door  100  is opened so that barrier  20  is moved upward solely by the power of the door opening mechanism. 
     FIGS. 7-14  show a preferred embodiment of guard assembly  10  in which bracket  60  is mounted to door  100  rather than to barrier  20  as in  FIGS. 1-6 . As shown in  FIG. 7 , bracket  60  includes a door plate  61  which is mounted to door  100  by bolts  68  (shown in  FIG. 10 ) and a hinge plate  63  which is pivotably connected to door plate  61  at pivot  62  such that hinge plate  63  may pivot with respect to door  100  and door plate  61 . Hinge plate  63  includes a hole  64  which provides for connection to and disconnection from barrier  20  as shown in  FIGS. 13 and 14 . Hinge plate  63  also includes hinge-plate aperture  67  at which tensioning element  65 , preferably a gas spring, is connected. Tensioning element  65  is further connected to door-plate aperture  66  on door plate  61 . Tensioning element  65  resists movement of hinge-plate aperture  67  toward door-plate aperture  66  when hinge plate  63  pivots about pivot  62 . 
     FIG. 8  shows bracket  60  mounted to door panel  104  while disconnected from barrier  20 . As shown, tensioning element  65  keeps hinge plate  63  at a position substantially perpendicular to door plate  61 .  FIG. 9  shows bracket  60  mounted to door panel  104  and connected to barrier  30  at hole  64 . As shown, guard coupling  31  rests on the shoulder  124  formed by trusses  122  when guard coupling  31  receives post  120  and barrier  20  is connected to door  100  by bracket  60 . Upper coupling  32  is also shown receiving post  120 .  FIG. 10  shows bracket  60  after pivoting of hinge plate  63  with respect to door plate  61 . As can be seen, tensioning element  65  is compressed by the pivoting of hinge plate  63  toward door plate  61 . 
     FIG. 11  depicts the opening of a door on a track  130  which includes a sloping portion  134  leading to a substantially horizontal portion. As can be seen, barrier  20  has pivoted with respect to door panel  104  to allow uprights  24  to extend substantially horizontally. As door panel  104  moves upward, tensioning elements  65  and hinge plates  63  keep uprights  24  substantially vertical until rollers  27  contact sloping portion  134  of track  130 . Then rollers  27  roll along track  130  and tensioning element  65  allows barrier  20  and hinge plate  63  to pivot about pivot  62 . When door panel  104  moves downward, tensioning element  65  pushes hinge plate  63  such that uprights  24  keep contact with track  130  and barrier  20  pivots back to its original position. In this way, barrier  20  can be moved into and out of the blocking position in which it extends across doorway  102 . 
     FIG. 12  depicts a preferred barrier  20  which includes a coupling  30  having a cable fitting  34  around which a cable  33  extends. Cable  33  preferably runs along barrier  20  to the opposite coupling  30  and opposite cable fitting  33 . Cable  33  provides sufficient tension to prevent anything from breaking through barrier  20  and damaging door  100  or falling off of the dock. In addition, cable  33  is sufficiently light-weight to optimize use of door  100  to remove barrier  20  from the doorway. Cable  33  may include two or more cables to provide increased tension. Cable fitting  33  is preferably aluminum or other similar lightweight metal and includes coupling  31  which receives post  120  and rests on shoulder  124  formed by trusses  122  when barrier  120  is in its blocking position. 
     FIGS. 13 and 14  depict the connection between bracket  60  and barrier  20 .  FIG. 13  shows bracket  60  when disconnected from barrier  20 . As can be seen hole  64  of hinge plate  63  is positioned above bores  74  of receiving brackets  73  which are mounted to cable fitting  34  and upright  24 . Pin  71  is held in pin brace  72  which mounted to cable fitting  73 . When the door moves downward, hinge plate  63  is received within the space between brackets  73  until hole  64  is aligned with bores  74 , which preferably occurs when the door is closed. Pin  71  is then passed through bores  74  and hole  64 , thereby connecting barrier  20  to bracket  60 , and thus to the door. 
   During the initial installation of guard assembly  10  on a door  100 , barrier  20  is positioned across doorway  102  and coupled to pre-existing posts  120  or posts  120  installed along with the assembly  10 . When barrier  20  is properly positioned, door plates  61  may be mounted to the door  100  along a door panel  104  which is at the same height as barrier  20 . Preferably hinge plate  63  is pivotably mounted to door plate  61  before door plate is mounted to door  100 . Door plate  61  is preferably positioned such that hole  64  in hinge plate aligns with bore  74  in brackets  73  when door  100  is closed and barrier  20  rests on shoulders  124 . Barrier  20  may remain in this blocking position while door  100  is opened or closed. To remove barrier  20  from doorway  104 , holes  64  and bores  74  are aligned and pins  71  are passed through brackets  73  and hinge plate  63  to connect barrier  20  to door  100 . Then door  100  is opened so that barrier  20  is moved upward solely by the power of the door opening mechanism. 
   While the invention has been described with respect to specific embodiments by way of illustration, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true scope and spirit of the invention.