Abstract:
A securing mechanism for coupling an exit device to a door. The securing mechanism comprises a bracket coupled to the exit device and a shaft having a first end and a second end and defining a longitudinal axis. The bracket defines a first aperture and a second aperture. The first end of the shaft extends through the first aperture and the second end of the shaft extends through the second aperture. The securing mechanism also comprises a first anchor slideably coupled to the shaft and moveable along the longitudinal axis between a first locked position and a first unlocked position and a second anchor slideably coupled to the shaft and moveable along the longitudinal axis between a second locked position and a second unlocked position. The first anchor frictionally engages the door in the first locked position and the second anchor frictionally engages the door in the second locked position.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to fasteners and fastening apparatuses, and more particularly to a method and apparatus for coupling an exit device to the middle panel or midrail of a door.  
         BACKGROUND OF THE INVENTION  
         [0002]    A variety of exit devices are commonly used for operating and opening doors. Generally, exit devices include a latching mechanism having a bolt or bolts, which secure the door to a doorframe to lock the door in a closed position. By activating the exit device, a user can retract the bolt from the doorframe and open the door. Commonly, exit devices are installed in doors located in commercial and public buildings and therefore are designed to be operated by a large number and variety of people, including children, the elderly, and the disabled. Therefore, exit devices that are easy to operate and require minimal strength and skill to operate are highly desirable. Additionally, exit devices are often designed to facilitate rapid building egress, such as, for example, during a fire, a natural disaster, or other similar emergency. Exit devices commonly include readily accessible actuators for use in an emergency by panicked or scared people.  
           [0003]    Moreover, exit devices are often located on the fronts of buildings and in business entryways. It is therefore desirable that the exit devices be aesthetically pleasing and not detract from the appearance of the door or the building. Typically, exit devices are secured to doors using fasteners, including bolts, nuts, screws, and the like. Additionally, custom designed mounting brackets, rails, and the like are often installed on the doors. In some cases, the fasteners and mounting brackets can be unsightly. It is therefore desirable to minimize the number of fasteners and mounting brackets used and to locate the fasteners and mounting brackets in unobtrusive places on the door and the exit device.  
           [0004]    Generally, exit devices are purchased separately from the doors and are installed in doors as the doors are being mounted in their respective doorframes. During installation, holes are generally drilled in the door and in the exit device to accommodate the fasteners. To properly mount the exit devices, the holes must be precisely located and threaded. The fasteners and mounting brackets are typically separate from the exit device and consequently are easily misplaced or lost during the installation and shipping processes. Moreover, in some cases the doors must be at least partially disassembled before the exit device can be properly installed.  
           [0005]    In addition to the above mentioned design considerations, exit devices that are durable, easy to manufacture, easy to assemble, and inexpensive are highly desirable for obvious reasons.  
         SUMMARY OF THE INVENTION  
         [0006]    According to the present invention, a securing mechanism for coupling an exit device to a door includes a shaft having a first end and a second end and defining a longitudinal axis. A bracket is coupled to the exit device and defines a first aperture and a second aperture. The first end of the shaft extends through the first aperture and the second end of the shaft extends through the second aperture. A first anchor is slideably coupled to the shaft and is moveable along the longitudinal axis between a first locked position and a first unlocked position. The first anchor frictionally engages the door in the first locked position. A second anchor is slideably coupled to the shaft and is moveable along the longitudinal axis between a second locked position and a second unlocked position. The second anchor frictionally engages the door in the second locked position.  
           [0007]    In some embodiments of the securing mechanism the first anchor and the second anchor are threadably coupled to the shaft. The first end is threaded in a first direction and the second end is threaded in a second opposite direction. A threaded fastener is movable along the shaft. The threaded fastener is operable to secure the first anchor in the first locked position and the second anchor in the second locked position.  
           [0008]    The bracket matingly engages the first and second anchors substantially preventing the first anchor and second anchor from rotating about the longitudinal axis with respect to the door. The first anchor includes a first plurality of axially extending protrusions. The first plurality of axially extending protrusions matingly engages the door when the first anchor is in the first locked position. The second anchor includes a second plurality of axially extending protrusions. The second plurality of axially extending protrusions matingly engages the door when the second anchor is in the second locked position.  
           [0009]    The shaft includes at least one flat face extending longitudinally along the longitudinal axis. A shoulder extends radially from the shaft. The shoulder limits the sliding movement of the first anchor and the second anchor along the longitudinal axis. The door includes a midrail defining a recess and the exit device is positioned in the recess.  
           [0010]    The present invention also includes a method of coupling the exit device to a door with a securing mechanism. The method comprises coupling the bracket to the exit device, rotating the shaft in a first direction about the longitudinal axis, moving the first anchor along the shaft toward the first end, moving the second anchor along the shaft toward the second end, and applying a compressive force to the door with the first and second anchors to hold the exit device and the securing mechanism in the door.  
           [0011]    Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description, claims, and drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    The present invention is further described with reference to the accompanying drawings, which show preferred embodiments of the present invention. However, it should be noted that the invention as disclosed in the accompanying drawings is illustrated by way of example only. The various elements and combinations of elements described below and illustrated in the drawings can be arranged and organized differently to result in embodiments which are still within the spirit and scope of the present invention.  
         [0013]    In the drawings, wherein like reference numerals indicate like parts:  
         [0014]    [0014]FIG. 1 is a perspective view of a door having an exit device and securing mechanisms embodying the present invention;  
         [0015]    [0015]FIG. 2 is a perspective view, with parts broken away, of the exit device and the securing mechanisms of FIG. 1;  
         [0016]    [0016]FIG. 3 is an enlarged perspective view, with parts broken away, of the exit device and the securing mechanisms of FIG. 2;  
         [0017]    [0017]FIG. 4 is an enlarged perspective view, with parts broken away, of one of the securing mechanisms of FIG. 3;  
         [0018]    [0018]FIG. 5 is an enlarged perspective view of one of the securing mechanism of FIG. 4;  
         [0019]    [0019]FIG. 6 is an exploded perspective view of one of the securing mechanism of FIG. 5;  
         [0020]    [0020]FIG. 7 is a plan view of the securing mechanism of FIG. 5; and  
         [0021]    [0021]FIG. 8 is a side view of the securing mechanism of FIG. 5. 
     
    
     DETAILED DESCRIPTION  
       [0022]    [0022]FIGS. 1 and 2 illustrate a door  12  including an active stile  14  positioned at one side and an inactive stile  16  positioned at the other side. Hinges (not shown) pivotably couple the inactive stile  16  to a doorframe (not shown). The active stile  14  includes a latching mechanism  19 , which when the door  12  is in a latched position, extends into the doorframe and secures the door  12  in the doorframe in a closed or latched position. To open the door, the latching mechanism  19  is retracted back into the active stile  14  so that the door  12  can be pivoted about the hinges to an open position.  
         [0023]    A midrail  20  extends between the inactive stile  16  and the active stile  14  and divides the door  12  into a lower portion  22  and an upper portion  24 . In the illustrated embodiment, the lower and upper portions  22 ,  24  include transparent glass panels  25 . However, one having ordinary skill in the art will appreciate that other materials commonly used in doors, including opaque and translucent materials, such as, for example, wood, steel, aluminum, and the like can also or alternately be used. Additionally, the term “midrail” as used herein and in the appended claims is meant to be illustrative and is not meant to indicate placement of the midrail  20  with respect to the door  12 . Also, the midrail  20  can, but does not necessarily, divide the door  12  into equally sized upper and lower portions  22 ,  24 .  
         [0024]    Referring to FIG. 3, the midrail  20  includes a front  26 , a back  28 , and a pair of sides  30  generally perpendicular to the front and back  26 ,  28 . Together, the sides  30  and the back  28  define a cutout or recessed portion  32 , which extends into the midrail  20 . An exit device  36  is located in the recessed portion  32  and includes sides  37 , a base plate  38  that is perpendicular to the sides  37  and rests against the back  28 , and a push bar  40 , which is spaced apart and is generally parallel to the base plate  38 . Rails  39  extend laterally along the sides of the base plate  38  adjacent to the sides  30  of the midrail  20  and operate to provide stability and rigidity to the base plate  38 . One having ordinary skill in the art will appreciate that in some applications other strengthening elements can also or alternately be used. Similarly, in some applications, particularly in applications in which the exit device  36  is relatively short and lightweight, the exit device  36  can operate without rails  39 . In operation, the push bar  40  is depressed inwardly toward the back  28  by a user to disengage the latching mechanism  19  from the doorframe in a known manner.  
         [0025]    Generally, exit devices  36  and doors  12  are sold separately and are assembled on location, immediately prior to or during door installation. To facilitate installation in a number of doors  12  having a number of different shapes and configurations, the exit device  36  includes securing mechanisms  42 ,  44 . Preferably, the securing mechanisms  42 ,  44  are coupled to the base plate  38  during assembly of the exit device  36 , as described in greater detail below. Therefore, the exit device  36  and the securing mechanisms  42 ,  44  can be supplied to builders and contractors as modular units, which can be installed relatively easily in midrails  20  at job sites with minimal effort and with a minimal number of tools. Moreover, as explained in more detail below, the inclusion of the securing mechanisms  42 ,  44  in the exit device  36  simplifies the installation of the exit devices  36  in doors  12  and preferably alleviates the need to drill unsightly holes in midrails  20  and to thread unsightly bolts and fasteners through the midrails  20  and the exit device  36 .  
         [0026]    In the illustrated embodiment, two securing mechanisms  42 ,  44  are coupled to the base plate  38 . As shown in FIGS. 2 and 3, the first securing mechanism  42  is coupled to a first end of the base plate  38  and the second securing mechanism  44  is coupled to a second opposite end of the base plate  38 . One having ordinary skill in the art will appreciate that in other embodiments, one, three, four, or more securing mechanisms  42 ,  44  can be spaced along the base plate  38 , depending, at least in part, upon the width of the door  12 , the length of the midrail  20 , and the size and weight of the exit device  36 .  
         [0027]    The securing mechanisms  42 ,  44  are substantially similar. Therefore, for purposes of description, one securing mechanism  42  is described in detail hereafter. Referring now to FIGS.  3 - 8 , the securing mechanism  42  includes a U-shaped bracket  50 , having a relatively horizontal center section  51 . The securing mechanism  42  is fixedly coupled to the base plate  38  with threaded fasteners  52  that extend through apertures  54  in the center section  51 . The fasteners  52  permanently or nearly permanently couple the U-shaped bracket  50  to the base plate  38 . In other embodiments, other conventional fasteners  52  could also or alternatively be used, including pins, rivets, nails, bolts, adhesives, keys, and the like. Alternatively or in addition, the U-shaped bracket  50  can be welded to the base plate  38 .  
         [0028]    The bracket  50  includes a first leg  58  and a second leg  60 . The first and second legs  58 ,  60  are perpendicular to and extend outwardly from the central section  51 . The first and second legs  58 ,  60  include generally L-shaped hooks or arms  62 ,  64 , respectively. The L-shaped arms  62 ,  64  extend away from the first and second legs  58 ,  60  in a direction substantially parallel to the base plate  38 , and then extend downward toward the base plate  38 . The first leg  58 , together with the L-shaped arm  62  and the base plate  38 , define a generally U-shaped first aperture  68 . Similarly, the second leg  60 , the L-shaped arm  64 , and the base plate  38  define a generally U-shaped second aperture  70 . Additionally, chamfers  72  extend through the first and second legs  58 ,  60  and the L-shaped arms  62 ,  64 , forming two substantially flat edges on the periphery of each of the first and second apertures  68 ,  70 . A longitudinal axis  76  (shown in FIG. 5) extends parallel to the central section  51  through the first and second apertures  68 ,  70 . The bracket  50  also includes a tab or tongue  80  that extends outwardly from the central section  51  between first and second legs  58 ,  60 , and then curves upwardly away from the base plate  38  in a direction substantially perpendicular to the central axis  76 .  
         [0029]    With reference to FIG. 6, a shaft  84  having a first end  86  and a second end  88  is coaxial with the longitudinal axis  76  and against tab  80 . The first end  86  extends through the first aperture  68  and the second end  88  extends through the second aperture  70 . The first and second ends  86 ,  88  are threaded in opposite directions. In the illustrated embodiment, the first end  86  includes right-hand threading  90  and the second end  88  includes left-hand threading  92 . However, one having ordinary skill in the art will appreciate that in other embodiments the first end  86  can include left-hand threading and the second end  88  can include right-hand threading.  
         [0030]    The shaft  84  includes a first operator  94 , which is located between the first and second ends  86 ,  88 . The first operator  94  includes one or more flat surfaces  96  so that a wrench (not shown) or another similar tool can easily grasp and turn the shaft  84  about the longitudinal axis  76 . In the illustrated embodiment, the first operator  94  is integrally formed with the shaft  84  and includes six flat surfaces  96 . In this manner, a conventional open-end wrench can be used to turn the first operator  94 . However, one having ordinary skill in the art will appreciate that in other embodiments the first operator  94  can include any number of flat surfaces  96  and can be engaged by any number of tools, including spanner wrenches and the like. Similarly, in other embodiments, recesses or protrusions can be machined into or extend from the first operator  94  respectively to facilitate engagement with other tools.  
         [0031]    The shaft  84  also includes a second operator  98 , which is substantially similar to and adjacent the first operator  94 . The second operator  98  also includes flat surfaces  96  and can be rotated with a tool about the longitudinal axis  76 . In the illustrated embodiment, the first and second operators  94 ,  98  are similarly sized and include the same number of flat surfaces  96  so that a single tool (e.g., a {fraction (7/16)}″ wrench) can be used to rotate both the first and second operators  94 ,  98 . However, in other embodiments, the first and second operators  94 ,  98  can be differently sized and can include different numbers and arrangements of flat surfaces  96  so that a user could use either of two different tools to rotate the shaft  84  about the longitudinal axis  76 .  
         [0032]    A central section  102  of the shaft  84  extends between the first and second operators  94 ,  98  and has a relatively small diameter. The first and second operators  94 ,  98  operate as shoulders and serve to hold the central section  102  against the tab  80 . Additionally, the first and second operators  94 ,  98  ensure that the shaft  84  remains in the correct position relative to the base plate  38  during operation of the exit device  36 .  
         [0033]    A first or right hand anchor  106  having a centrally located internally threaded through bore  108  is threaded onto the first end  86  of the shaft  84  and a second or left hand anchor  110  having a centrally located internally threaded through bore  112  is threaded onto the second end  88  of the shaft  84 . In the illustrated embodiment, through bore  108  includes right-hand threading and through bore  112  includes left-hand threading. However, as discussed above with respect to the threading of the shaft  84 , in other embodiments through bore  108  can include left-hand threading and through bore  112  can include right-hand threading.  
         [0034]    During operation, the first and second anchors  106 ,  110  move axially along the shaft  84  and bases  114  of the anchors  106 ,  110  slide along the base plate  38 . The first and second operators  94 ,  98  act as stops, limiting the movement of the first and second anchors  106 ,  110  along the shaft  84  and preventing the first and second anchors  106 ,  110  from moving onto the unthreaded central section  102  of the shaft  84 .  
         [0035]    The first and second anchors  106 ,  110  include blocks  116 ,  118 , respectively. The blocks  116 ,  118  have interior sides  120  facing inwardly toward the first and second operators  94 ,  98  and exterior sides  122  facing outwardly toward the sides  30  of the midrail  20 . Lips  126  extend laterally from the exterior sides  122  through appropriately sized apertures  130  (shown in FIG. 4) in the rails  39  toward the sides  30  of the midrail  20 . The lips  126  have a low profile and therefore do not interfere with the operation of the exit device  36  when the first and second anchors  106 ,  110  move outwardly toward the sides  30  of the midrail  20 . More particularly, the low profile allows the lips  126  to move laterally without contacting the push bar  40  when the push bar  40  is depressed. Additionally, the low profile of the lips  126  alleviates the need to include cutouts in the push bar  40  to accommodate the movement of the first and second anchors  106 ,  110 . This is particularly advantageous because the inclusion of these cutouts would necessitate an additional machining operation. Moreover, these cutouts would act as pinch points and would weaken the push bar  40 . Referring back to FIG. 4, exterior surfaces  134  of the lips  126  include a plurality of conical protrusions  136 , best seen in FIG. 5. Channels  140  extend laterally along upper surfaces  142  of the lips  126 . The channels  140  extend into the through bores  108 ,  112  and accommodate the shaft  84 .  
         [0036]    Upper surfaces  146  of the first and second blocks  116 ,  118  include flat sides  148 , which are sized and angled to closely mate with the chamfers  72 . In this manner, the first and second anchors  106 ,  110  can move laterally along the longitudinal axis  76  through the first and second apertures  68 ,  70  but are prevented from moving perpendicular to the longitudinal axis  76  by the first and second legs  62 ,  64 , respectively. Additionally, the mating relationship between the flat sides  148  and the flat edges  72  simplifies assembly of the securing mechanism  42  and ensures that the first and second anchors  106 ,  110  are positioned correctly with respect to the bracket  50  during assembly of the securing mechanism  42 .  
         [0037]    A lock nut  152  is threaded onto the shaft  84  between the second operator  98  and the first anchor  106 . In the illustrated embodiment, the lock nut  152  is a commercially available {fraction (7/16)}″ hex jam nut. In alternative embodiments of the present invention other fasteners, including threaded and non-threaded fasteners, such as, for example, lock washers, pins, and the like can also or alternatively be used. Similarly, one having ordinary skill in the art will appreciate that the lock nut  152  could also or alternately be positioned between the first operator  94  and the second anchor  110 . In the illustrated embodiment, the lock nut  152  is not the same size as the first and second operators  94 ,  98 . However, one having ordinary skill in the art will appreciate that the lock nut  152  and the first and second operators  94 ,  98  can be the same size so that a single wrench can be used to tighten or loosen the lock nut  152  and the first and second operators  94 ,  98 .  
         [0038]    The present invention as described herein and as shown in the figures includes a single lock nut  152  positioned between the first anchor  106  and the second operator  98 . However, one having ordinary skill in the art will appreciate that the present invention could also include a second lock nut  152  positioned between the second anchor  110  and the first operator  94 .  
         [0039]    The present invention also includes a method for installing the exit device  36  in the door  12  using securing mechanisms  42 ,  44 . As mentioned above, the exit device  36  is inserted into the cutout  32  in the midrail  20 . The installer then removes fasteners  156  (shown in FIG. 1), which hold the sides  37  on the exit device  36 . One or both of the sides  37  is then removed. A removable portion  157  of the push bar  40  is then removed laterally toward the open end of the exit device  36 . The installer can then gain access to the securing mechanisms  42 ,  44 .  
         [0040]    Prior to installation, the first and second anchors  106 ,  110  are preferably in a retracted position. In the retracted position, the interior sides  120  of the blocks  116 ,  118  are preferably adjacent to the first and second operators  94 ,  98 , respectively. Additionally, the lock nut  152  is preferably adjacent the second operator  98 .  
         [0041]    Using a wrench or another similar tool, the installer rotates the first or second operator  94 ,  98  in a first direction (as indicated by arrow  158 ; FIG. 5) about the longitudinal axis  76  to extend the first and second anchors  106 ,  110  laterally toward the sides  30  of the midrail  20 . When the first and second anchors  106 ,  110  are in the extended position they exert compressive forces against the sides  30 , securing the exit device  36  in the midrail  20 . Additionally, the conical protrusions  136  on the lips  126  are forced into the sides  30 , securing the first and second anchors  106 ,  110  in position and preventing the first and second anchors  106 ,  110  from moving laterally along the sides  30  of the midrail  20 . To remove the exit device  36  from the cutout  32  or to reposition the exit device  36  in the cutout  32 , the installer can retract the first and second anchors  106 ,  110  by rotating the first or second operator  94 ,  98  in a second opposite direction (indicated by arrow  160 ; FIG. 5).  
         [0042]    Once the first and second anchors  106 ,  110  are in the extended position and the installer is satisfied that the first and second anchors  106 ,  110  will securely hold the exit device  36  in the cutout  32 , the installer locks the securing mechanism  42  in the extended position by moving and tightening the lock nut  152  into a locked position adjacent the interior side  120  of the first anchor  106 . The lock nut  152  then holds the securing mechanism  42  in the locked position and ensures that door vibrations do not loosen the securing mechanism  42 .  
         [0043]    In a similar manner, the installer secures the other end of the exit device  36  in the cutout  32  with the securing mechanism  44 . Additionally, as mentioned above, additional securing mechanisms (not shown) can be positioned along the length of the exit device  36  as desired.  
         [0044]    The embodiments described above and illustrated in the drawings are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art, that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention as set forth in the appended claims. The functions of the various elements and assemblies of the present invention can be changed to a significant degree without departing from the spirit and scope of the present invention.