Abstract:
A door assembly for a chute system comprising a door pivotally connected to a frame assembly mountable around an opening in a chute system. The door is manufactured from stainless steel and is free of welds. The door includes an automatic closer mounted to its interior surface and being directly connected to the frame assembly at one end and to the door at the other end. When the door is opened, the closer moves with the door out of the opening to the chute system, thereby increasing the usable space for inserting articles into the chute. The closer does not intrude into the interior of the chute when the door is in a closed position. The door may also include a deflector plate mounted proximate the door hinge to protect the hinge and prevent debris from articles inserted into the chute from dropping into the gap between the door and frame and interfering with the action of the hinge.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority from U.S. Provisional Patent Application Ser. No. 60/613,422; filed Sep. 28, 2004, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Technical Field  
         [0003]     This invention generally relates to a door assembly. More particularly, the invention relates to a fire-rated door assembly for a chute system. Specifically, the invention relates to a door assembly which includes a weld-free door having an automatic door closer mounted on the interior surface thereof and which includes a deflector plate for covering the door hinge during operation.  
         [0004]     2. Background Information  
         [0005]     In tall building structures like apartments or office buildings, it is common to provide chute systems which are used by the occupants of the building to dispose of trash or to send laundry to lower floors in the building.  
         [0006]     The chute systems generally consist of a large, vertically-oriented main chute that has a plurality of branches, each of which originates in an opening on one of the individual levels of the building structure. Each opening to the chute system is provided with a door to cover that opening when the chute is not in use. The occupant can open the door and place a bag of garbage or laundry, for example, through the opening and then release the bag. The bag slides down the chute branch to the main chute and then drops or slides downwardly to a collection bin disposed a spaced number of floors away from the opening in question.  
         [0007]     The door that covers the opening to the chute branch has to meet certain safety requirements and standards. One of those requirements is that the chute door must close automatically when released. Furthermore, the door must meet UL (Underwriters Laboratory Inc.) fire codes to attempt to prevent any fires from spreading from one floor of a building to another through the chute system.  
         [0008]     Currently known chute door designs typically include a recessed frame that fits inside the chute opening and serves as mounting structure for the chute door. Furthermore, chute doors that are presently known in the art generally use fairly complex systems of linkages to shut the door once it is released. The inclusion of the linkage is usually a result of trying to maximize the angle of door opening while preserving the self-closing feature of the door. Other designs, such as those of U.S. Pat. Nos. 6,062,368; 6,186,306 and 6,269,928 utilize the linkages to both close the door and provide auxiliary functions such as automatic locking. The linkage and closer assemblies used in the prior art are typically mounted inside the chute or on the frame on one side of the door in order to meet the code requirements and reduce the possibility of contamination of the linkages and closer assemblies.  
         [0009]     The aforementioned usage of linkage and closer assemblies results in deficiencies in currently known chute doors. The mounting of the linkage and closer assembly in the chute or on the side of the door takes up significant space in the chute opening and reduces the usable area of the opening for disposable of articles therethrough. When the linkage and closer assemblies are placed to the side of the door, the width of the door is necessarily decreased to allow for installation into a fixed width chute opening. Thus, the door size and the usable chute opening are both reduced. Currently known designs also have the linkages and closer attached to the frame inside the chute. As the door is opened, the mechanism remains essentially in the same position, namely inside the chute and obstructing a portion of the opening. Furthermore, the closer assembly is typically the highest maintenance and replacement item for chute doors. When the closer is fixedly mounted to a structure inside the chute, it can be difficult to access, remove and reinstall. Some known designs therefore require that the entire door assembly be pulled out of the chute for maintenance of the closer assembly.  
         [0010]     A second deficiency in the currently known art relates to the actual installation of the door. The chute system is typically installed in the building before the finishing of the interior surfaces and installation of the chute doors. Variations in wall thickness, chute opening size, squareness of the opening etc., can require modifications to the door assembly to achieve a proper fit and function of the door. The safety standards and ratings of these types of doors require fairly precise fits and connections which may be compromised by the typical variations found in rough construction. The result is often a need to custom fit each door installation with field-cuts or modifications in order to get the door assembly to fit into rough construction. This obviously leads to an increase in the number of man hours such an installation procedure costs and therefore leads to an increase in the total cost of installation of a chute system into a building structure. Furthermore, if the installation requires field modifications, the fit and alignment of the finish frame can be adversely affected and result in an aesthetically displeasing door assembly.  
         [0011]     Previously known doors are manufactured with the interior surfaces of the door being made of cheaper materials such as aluminized or galvanized steel and having typically been welded together. The applicant has recognized that both the type of steel used and the presence of welds tends to increase the risk of contamination of the door surfaces. This risk of contamination increases because aluminized or galvanized steel may react with accidentally spilled materials and liquids resulting in early deterioration of the interior door surface. Furthermore, welds tend to have small pitted areas therein and consequently debris from the garbage can accumulate in both the welded areas and on the deteriorating surfaces, thus allowing bacterial colonies to flourish on the door.  
         [0012]     There is therefore a need in the art for a door assembly for a chute system that is capable of meeting regulations and codes governing this type of installation; that is easy to install and maintain, that tends to reduce the potential for contamination of the door and yet leaves the maximum amount of space available in the opening in order to allow articles to be inserted therethrough and be deposited into the chute.  
       SUMMARY OF THE INVENTION  
       [0013]     Consistent with the foregoing objects, and in accordance with the invention as embodied and broadly described herein, a method and apparatus are disclosed in one embodiment of the present invention as including a chute door with external mounting frame and a direct acting automatic closer.  
         [0014]     It is therefore an object of the present invention to provide a chute door that meets existing codes and standards such as fire ratings.  
         [0015]     A further object of the present invention is to provide a chute door that maximizes the usable area of the chute opening.  
         [0016]     Another object of the present invention is to provide a chute door that accommodates the inaccuracies of rough opening upon installation without the need for special modifications.  
         [0017]     Another object of the present invention is to provide a chute door that facilitates access to the closer for maintenance and repair.  
         [0018]     Another object of the present invention is to provide a chute door that is simple in design and economical to produce.  
         [0019]     The door assembly of the present invention includes a frame assembly comprising a separate mounting frame and finish frame for a chute door. An automatic door closer is attached to the frame assembly at one end and to the door at the other end. The automatic closer acts directly on the door and is mounted directly on the interior surface of the door. The closer therefore does not occupy part of the chute opening when the door is open because it moves with the door into and out of the opening to the chute. The door is fabricated with a flange of material that overlaps the trim frame externally to provide a seal for the chute opening. The mounting frame has slotted holes on first legs thereof to facilitate installation and adjustments of the door and frame assembly to the chute system. The first legs of the mounting frame are longer and the slotted holes facilitate the mounting and adjusting of the door assembly to fit the chute opening. The finish frame can be properly fitted independently of the mounting frame so that the adjustments made during installation do not affect the visible frame on the exterior of the wall. The use of separate mounting frames and trim frames increases the ease with which the door assembly can be installed and therefore tends to reduce the costs associated therewith.  
         [0020]     The present invention tends to overcome the previously stated problems with the prior art by not using linkages for the closer, by having an easily removable closer cover for easier access to the closer for maintenance and by having longer first legs on the mounting frame with slotted fastener points to allow for adjustment of the positioning of the mounting frame during installation.  
         [0021]     The present invention tends to not narrow the chute opening because of the type of closer that is utilized to automatically close the door and because that automatic closer is mounted to the interior surface of the door. Preferably the closer comprises a mechanical coil spring which includes dampening hydraulic fluid or, alternatively, a gas spring. Additionally, the closer moves with the door in and out of the opening. Consequently, when the door is opened the usable space is maximized. Furthermore, the closer does not protrude into the vertical portion of the chute when the door is in a closed position. It should be noted that chute systems can vary in size and consequently it is sometime necessary to use fairly large door assemblies to close larger chute openings. In these larger door assemblies, more than one automatic closer can be utilized to close the door. This can be accomplished by mounting a second stop plate, automatic closer and cover on the interior surface of the door. The two stop plates, closers and related covers are mirror images of each other.  
         [0022]     When the door is opened, the closer is easily accessed for maintenance as it lies outside of the chute and the only step required to reach it is the removal of the protective cover. With the cover removed, the automatic closer can be adjusted, removed or replaced. This increases the ease with which the automatic closer can be maintained and reduces the costs associated therewith.  
         [0023]     Furthermore, the door is provided with a deflector plate for protecting the door hinge and thereby reducing the possibility for debris to accumulate in the gap between the door and frame assembly. This also reduces the possibility of that the door will not close properly because debris has become trapped in that gap and is interfering with the operation of the hinge. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     The preferred embodiments of the invention, illustrative of the best mode in which applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings and are particularly and distinctly pointed out and set forth in the appended claims.  
         [0025]      FIG. 1  is a perspective view of the door assembly in accordance with the present invention;  
         [0026]      FIG. 2  is a right side view of the door assembly of  FIG. 1 ;  
         [0027]      FIG. 3  is a left side view of the door assembly of  FIG. 1 ;  
         [0028]      FIG. 4A  is a cross-sectional side view of the door assembly through line  4 A- 4 A of  FIG. 1 ;  
         [0029]      FIG. 4B  is a cross-sectional side view of the door assembly through line  4 B- 4 B of  FIG. 1 ;  
         [0030]      FIG. 5  is a rear view of the door assembly in a closed position with the cover for the automatic closing mechanism removed;  
         [0031]      FIG. 6  is a perspective view of the door assembly positioned adjacent an access opening in a wall;  
         [0032]      FIG. 7  is a partial cross-sectional right side view of the door assembly mounted in the access opening with the door in a closed position;  
         [0033]      FIG. 8  is partial cross-sectional right side view of the door assembly mounted in the opening with the door in an open position;  
         [0034]      FIG. 9  is a perspective view of the door assembly mounted around the access opening in the wall and showing the door in an open position;  
         [0035]      FIG. 10  is an enlarged cross-sectional view of the circled area of  FIG. 8 ; and  
         [0036]      FIG. 11  is a rear view of the installed door assembly with the door in an open position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0037]     It will be readily understood that the components of the present invention, as generally described and illustrated in the attached figures, could be arranged and designed in a wide variety of different configurations. So, for example, while the door assembly is shown with the door hinged to the frame proximate a bottom end thereof, the door assembly could, alternatively, be hinged proximate its top end or on either one of the left-hand side and right-hand side thereof. Thus, the following detailed description and attached drawings of the invention are not intended to limit the scope of the invention, as claimed, but are merely representative of a preferred embodiment of the apparatus in accordance with the present invention.  
         [0038]     The embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout this specification. Those of ordinary skill in the art will, of course, appreciate that various modifications may easily be made without departing from the spirit of the invention.  
         [0039]     Referring to  FIGS. 1-6  there is shown a door assembly in accordance with the present invention and generally indicated at  10 . Door assembly  10  is adapted to selectively allow access to a chute that forms part of a chute system. The chute system is not shown in its entirety, but preferably is of the type typically provided in multi-story buildings where it is desirable to move articles, such as garbage or laundry, easily and efficiently from an upper floor of the building through to a collection area on a lower floor of the building. The chutes in such systems typically include a riser section that runs from the top floor of the building through to the lowest floor of the building and a plurality of throat sections that join the riser at intervals. The riser may be of any size, but typically the risers are in the range of 24-36 inches in diameter. The throat sections are typically around 10 inches deep and extend off the riser at each floor and terminate in an access opening in a building wall. The throat section preferably has an inclined bottom wall so that articles inserted through the opening slide down that bottom wall and drop into the riser. The chute system will typically include an opening on each floor of building. The door assembly of the present invention is installed at said access openings. A collection bin may be positioned beneath a terminal opening in the riser to catch any laundry or garbage bags dropped through one of the openings in a floor remote from the terminal opening.  
         [0040]     Door assembly  10  is adapted to be installed around an access opening  14  in a building wall  16 . Door assembly  10  comprises a frame assembly  18  onto which a door  20  is pivotally mounted. For the purposes of the present description,  FIGS. 6-11  show a portion of a throat section  12  of a chute that terminates in access opening  14 . It will be understood, that while the riser is not shown in the attached figures, it lies approximately 8-10 inches beyond the edge  18   a  of frame assembly  18 .  
         [0041]     In accordance with one of the specific features of the present invention, frame assembly  18  comprises a mounting frame  22  and a trim frame  24  ( FIGS. 4A-6 ). Mounting frame  22  is substantially rectangular in shape and is L-shaped in cross-section having first legs  26  and second legs  28  disposed at substantially ninety degrees to each other. It will be seen from  FIG. 7 , for example, that the first leg  26   b  of mounting frame  22   b  that is to abut the upper end of opening  14  is longer than the first leg  26   a  of mounting frame  22   a  that is to abut the lower end of opening  14 . First legs  26   b  are typically between 1½inches to 2 inches wide and consequently throat section  12  of chute system terminates approximately 8 inches beyond the end  27  ( FIG. 7 ) of first legs  26   b . While mounting frame  22  preferably is a single unitary member, it may, alternatively, be made up of more than one separate members. Trim frame  24  is preferably formed from one or more separate members, but could alternatively be formed from a single unitary member.  
         [0042]     Mounting frame  22  is positioned so that its respective first legs  26  extend into access opening  14  and are adapted to abut an interior surface  30  of chute  12 . The second legs  28  of mounting frame  22  are positioned to abut an exterior surface  32  of wall  16  surrounding opening  14 . Each first leg  26  defines a plurality of elongated slots  34  disposed at spaced intervals along the length of that first leg  26 . Slots  34  are elongated in shape to allow the position of mounting frame  22  to be adjusted relative to the outermost edge  36  of opening  14 . This enables the door assembly  10  to be installed in a correct position even if there are slight variations in the rough construction of wall  16 . At least some of first legs  26  are secured to the respective interior surface  30  of chute  12  by way of fasteners  36 , such as screws or nails. When first legs  26  of mounting frame  22  are positioned correctly, second legs  28  lie in abutting contact with the exterior surface  32  of wall  16 . The members of trim frame  24  are positioned over second legs  28  and in partial abutting contact with exterior surface  32  of wall  16  whereby second legs  28  lie intermediate trim frame  24  and exterior surface  32 . Trim frame  24  extends outwardly beyond second legs  28  as may be seen in  FIGS. 4A, 4B  and  5  and is bent inwardly in order to contact the exterior surface  32  of wall  16 . A plurality of fasteners  42  secure trim frame  24  to second legs  28 .  
         [0043]     Referring to  FIGS. 4A and 4B , and in accordance with a specific feature of the present invention, door  20  preferably is manufactured from two sheets of stainless steel that are mechanically secured together. A peripheral region  56  of the first sheet is bent over and crimped around the peripheral edge  58  of the second sheet so that the door is manufactured substantially free of welds. Door  20  is thereby formed with an exterior wall  44  having an exterior surface  44   a  and an interior wall  46  having an interior surface  46   a . Disposed between the exterior and interior walls  46 ,  44 , are two opposing side walls  48 , a top wall  50  and a bottom wall  52 . Top wall  50 , bottom wall  52  and side walls  48  are substantially continuous with interior wall  46 . At least interior wall  46  of door  20  is formed as a single, substantially continuous sheet of stainless steel that is free of welds. Preferably, the entire door  20  is manufactured in such a manner as to be free of welds. Exterior surface  44   a  may be manufactured with a brushed finish, while interior surface preferably has a shiny finish so as to reduce the possibility for bacteria to accumulate on the surface. A fire resistant or retardant insulating material  54  preferably is sandwiched between exterior and interior surfaces  44 ,  46 .  
         [0044]     The top and sides of exterior surface  44   a  where the two sheets of steel are crimped together thereby form a multilayered flange  60  that extends outwardly beyond the top wall  50  and side walls  48  of door  20 , as can be most easily seen in  FIG. 4A  and  FIG. 6 . Flange  60  abuts trim frame  24  and seals the gap  62  formed between top wall  50  of door  20  and first leg  26   b . This arrangement reduces the possibility that a fire would be transmitted through the chute system from one floor to another. Furthermore, the overlapping of trim frame  24  by flange  60  also tends to reduce any foul smelling odors emanating from garbage moving through the chute system.  
         [0045]     Furthermore, although not illustrated in the attached figures, it will be understood that frame assembly  18  may be configured to receive a seal member (not shown) disposed so as to lay intermediate flange  60  and trim frame  24  when door  20  is in a closed position. The seal could be a rubber strip attached to one of the flange  60  and trim frame  24 .  
         [0046]     Door  20  is pivotally mounted to frame assembly  18  by way of a hinge  64 . As may be most easily seen in  FIG. 10 , a first part  66  of hinge  64  is fixedly secured to frame assembly  18  and a second part  68  of hinge  64  is fixedly secured to bottom wall  52  of door  20 . A pivot rod  70  extends through hinge  64  and permits door  20  to be rotatably moved between a closed position (shown in  FIGS. 4B &amp; 7 ) and an open position (shown in  FIGS. 8 &amp; 10 ). Hinge  64  runs substantially the entire width of door  20  but does not extend into flanges  60 .  
         [0047]     In accordance with one of the specific features of the present invention, a second hinge  74  is mounted to door  20  a spaced distance from the hinge  64 . Second hinge  74  comprises a substantially L-shaped deflector plate  72  ( FIG. 5 ) mounted for pivotal motion about a second pivot rod  75 . As may best be seen from  FIG. 6 , second hinge  74  runs substantially the entire width of door  20 . A first arm  76  of deflector plate  72  is fixedly secured to bottom wall  52  of door  20 . A second arm  78  of deflector plate  72  is free of attachment to either the frame assembly  18  or door  20 , and rests upon at least a portion of mounting frame  22  and a first part of the chute  12 . It will be understood that while first arm  76  of deflector plate  72  is illustrated as laying intermediate bottom wall  52  of door  20  and second part  68  of hinge  64 , the second part  68  of hinge  64  could, alternatively, be disposed intermediate first arm  76  of deflector plate  72  and bottom wall  52  of door  20 . As door  20  rotates between a closed position and an open position, deflector plate  72  rotates about second pivot rod  75  and second arm  78  substantially remains in contact mounting frame  22  and a first part of chute  12  with as the door pivots between an open and a closed position. Deflector plate  72  thereby continuously covers access to the gap between bottom wall  52  of door and first leg  26  of mounting frame  22 . It should be noted from  FIG. 7 , that the first leg  26   a  of the lower part  22   a  of mounting frame  22 , is smaller in width than is the first leg  26   b  of the upper part  22   b  of the mounting frame  22 . The mounting frame  22  is shaped in this way to allow second arm  78  of deflector plate  72  to more easily rest on a first part  12   a  of chute  12  and to pivot with door  20 . It should also be noted that second arm  78  of deflector plate  72  does not jut out into the interior of the chute  12  when door  20  is closed where it could snag articles that are sliding through the chute system. When door  20  is in its fully open position as shown in  FIG. 10 , second arm  78  of deflector plate  72  pivots with door  20  and stays resting on frame assembly  18 , and more specifically on the narrower width first leg  26   a  of lower part  22   a  of mounting frame  22 . Once again, second arm  78  does not extend substantially outwardly into the throat section of chute  12  and therefore articles being inserted through access opening  14  do not become snagged on deflector plate  72 . Furthermore, articles traveling through the riser section of the chute do not engage second arm  78 . Deflector plate  72  therefore continuously covers hinge  64  and substantially prevents laundry or debris from garbage inserted through opening  14 , from coming into contact with hinge  64 . The possible accumulation of garbage in the gap between the bottom of door  20  and frame member  22  and the consequent loss of operation of hinge  64  is therefore substantially reduced.  
         [0048]     Door  20  is further provided with a handle  80  and latching mechanism (not shown). Any suitable type of latching mechanism may be utilized on door  20 . In the preferred embodiment illustrated in  FIGS. 1 and 6 , handle  80  is fastened to door  20  through both interior and exterior surfaces  46 ,  44  and a latch  82  of the latching mechanism extends outwardly from top wall  50  of door  20  and is adapted to engage in a recess (not shown) in frame assembly  18 . Handle  80  provides an easy and convenient way for a person to open and close door  20  and may also be of a type that specifically addresses the needs of the elderly or the physically challenged. The latching mechanism allows a person to unlatch door  20  so that access can be gained to opening  14  and chute  12 . When the person has deposited their garbage, laundry or other appropriate articles into chute  12 , then latch  82  will be engaged to secure door  20  in the closed position so that the seal is maintained between trim frame  24  and flange  60 .  
         [0049]     In accordance with another specific feature of the present invention, a chute guide  84  may extend outwardly away from interior surface  46   a  of door  20 . As implied, chute guide  84  helps direct articles such as garbage bags and laundry through opening  14  and into chute  12 . Although not illustrated in the attached drawings, chute guide  84  can also include a formed edge or additional hardware to serve as a stop to the opening angle of the door  20 . Chute guide  84  preferably is also manufactured from stainless steel.  
         [0050]     A stop plate extends outwardly away from interior surface  46   a  and from proximate the opposite side wall  48  of door  20  from chute guide  84 . Stop plate  86  defines an arcuate slot  88  through which a slide rod  90  passes. Slide rod  90  is fixedly attached at one end to a first leg  26  of one of mounting frame  22 . Slide rod  90  is mounted at the other end to an automatic door closer  92  as will be hereinafter described. Stop plate  86  preferably includes a reinforcing area  94  disposed proximate an end of slot  88  so that slide rod  90  does not damage slot  88  when door  20  is opened and closed. Reinforcing area may be semicircular or angular in shape.  
         [0051]     As mentioned above and shown in  FIG. 8 , the automatic door closer  92  is mounted on interior surface  46   a  of door  20 . In the preferred embodiment of the invention, door closer  92  comprises a cylinder  95  that houses a mechanical coil spring with hydraulic dampening fluid therein or, alternatively, a gas spring. The spring (not shown) within cylinder  95  urges closer  92  to a more compressed condition. A piston rod  96  extends outwardly from a first end of cylinder  95  and is pivotally connected to a mounting bracket  98  extending from interior surface  46  of door  20 . The other end of closer  92  is pivotally connected via a mounting ring  100  to the slide rod  90 , which is in turn rigidly connected to the adjacent mounting frame  22 . Closer  92  ensures that flange  60  of door  20  lies in abutting contact with trim frame  24  thereby reducing the chances of flames or smoke from a fire spreading through the chute system. Closer  92  also has spring and dampening properties such that it will not allow door  20  to close with a hard slamming motion. Closer  92  is mounted adjacent stop plate  86  so that it is out of the way when articles are inserted into opening  14  and therefore does not tend to obstruct opening  14 . Slide rod  90  provides both a means for mounting closer  92  and for contacting the end  88   a  ( FIG. 8 ) of slot  88  to limit the travel of door  20 . This limit is redundant to the maximum extension of closer  92 .  
         [0052]     A removable cover  104  for closer  92  is secured to stop plate  86  by way of a plurality of fasteners  106 . In accordance with one of the specific features of the present invention, both stop plate  86  and closer  92  are also manufactured from stainless steel. A plurality of interlocking tabs  108  ( FIG. 5 ) are provided on interior surface  46   a  of door  20  to provide securing points for the base  110  of cover  104 . As may be seen from  FIG. 11 , cover  104  is shaped and sized to fit tightly over closer  92  so that closer  92  is disposed between the vertical walls of stop plate  86  and cover  104 . Cover  104  thereby protects closer  92  by substantially preventing articles inserted through opening  14  from coming into contact with closer  92 . Furthermore, cover  104  is as compact as possible so that the least amount of room is taken up by the closer  92  and cover  104 . This reduces the amount of interference that these components present to articles being inserted through opening  14 . When door  20  is in the open position shown in  FIG. 9 , fasteners  106  can be removed so that cover  104  can be removed. Cover  104  is released from tabs  108  on door  20  by sliding cover  104  in a direction opposite to the direction that the free ends of the tabs  108  extend. Cover  104  is removed so that maintenance can be performed upon closer  92 .  
         [0053]     It will be understood that stop plate  86 , closer  92  and cover  104  can be placed on either side or, in larger doors on both sides, of the interior surface  46   a  of door  20 . Furthermore, it will be understood that chute guide  84  can be completely omitted from door assembly  10  to facilitate access to opening  14 . Additionally, if hinge  64  is provided in a position other than mounted at the bottom of door  20 , then stop plate  86 , closer  92  and cover  104  will be positioned appropriately for the door to function properly.  
         [0054]     Referring to  FIGS. 7-11  and presuming that opening  14  has been cut into wall  16  and the chute system is already installed in building, door assembly is installed as follows. Mounting frame  22  is installed into opening  14  by generally positioning mounting frame  22  so that an outermost edge  30   a  of wall  16  lies within the apex  22   c  ( FIG. 4A ) of the first and second legs  26 ,  28  of mounting frame  22 . Fasteners  36  are loosely inserted through slots  34  in first legs  26  of mounting frame  22 , thus loosely holding mounting frame against interior surface  30  of chute  12 . The position of mounting frame  22  can then be adjusted by sliding frame  22  relative to fasteners  36 . When mounting frame  22  is in the correct position, fasteners  36  are tightly secured into place. Once mounting frame  22  is installed in opening  14 , the members of trim frame  24  are positioned over second legs  28  of mounting frame  22  and in abutting contact with at least a portion of exterior surface  32  of wall  16  surrounding opening  14 . Fasteners  42  are then used to secure trim frame  24  to second legs  28  of mounting frame  22 . Door  20  is secured, by hinge  64  to the selected one of the top, bottom and side portions of mounting frame  22  to allow door  20  to open in the desired direction. Care must be taken to ensure that flange  60  on door  20  overlaps trim frame  24  to a sufficient degree to ensure that chute opening  14  is adequately sealed when door  20  is in the closed position. The installer installs a cooperating latching mechanism on door  20  and mounting frame  22  and installs deflector plate  72  to cover hinge  64  if these components have not been previously installed on door  20 . Furthermore, if the automatic closer  92  has not been previously installed on interior surface  46   a  of door  20 , then closer  92  may be mounted thereon at this point by securing the piston rod  96  to bracket  98 . The other end of cylinder  95  is connected to slide rod  90 . Cover  104  is then secured over closer  92 .  
         [0055]     When a building occupant wants to open door assembly  10  to dispose of a bag of garbage, for instance, they grasp handle  80  and either depress a button or turn the handle (depending on the type of handle installed) to disengage latch  82  from frame assembly  18 . The person pulls door  20  downwardly in the direction of arrow “A” ( FIG. 8 ). This causes door  20  to rotate about pivot rod  70 , forcing piston rod  96  to be drawn out of cylinder  95 , causing slide rod  90  to slide along arcuate slot  88 . As door  20  rotates, deflector plate  72  pivots about pivot rod  75  from the position shown in  FIG. 7  to the position shown in  FIG. 9 . As may be seen, deflector plate  72  continuously covers hinge  64  during this opening motion. When slide rod  90  reaches end  88   a  of slot  88 , the opening motion of door  20  stops. The person can then push a bag of garbage (not shown) or an article of clothing, depending on the use of the chute system, through opening  14 . The bag is released into chute  12  and drops through the chute system under the action of gravity. Because closer  92  and cover  104  are as small as possible and are positioned off to one side of the interior surface  46   a  of door  20 , they do not substantially prevent or hinder the insertion of the bag of garbage into chute  12 . It should also be noted that the uppermost corners  112  ( FIG. 11 ) of cover  104  are rounded to prevent snagging of the bag of garbage thereon. However, should the bag break open for some reason, the interior surface  46   a  of door  20  is free of welds, is made of stainless steel and is provided with a shiny external surface. This prevents any small bits of garbage from collecting in cracks and crevices in interior surface  46   a  of door. Furthermore, because deflector plate  72  continuously covers hinge  64  and the gap formed between the bottom wall  52  of door and first leg  26   a  of mounting frame  22   a  ( FIG. 10 ), no small bits of garbage and debris can accumulate in that gap. This reduces the possibility of contamination of door  20  and ensures that door  20  can open and close properly because debris does not fall between bottom wall  52  and mounting frame  22   a . Once the bag of garbage has been released into chute  12 , the person can let go of handle  80  and automatic closer  92  will cause the door to close by itself. This is accomplished because piston rod  96  automatically returns to its retracted position inside cylinder  95 , causing door to rotate in the opposite direction to arrow “A” ( FIG. 8 ). As this occurs, arcuate slot  99  slides past slide rod  90  until slide rod  90  is disposed proximate the second end  88   b  of slot  88 . Latch  82  slides back into the cooperating recess (not shown) in mounting frame  22  and flange  60  is thereby held in abutting contact with trim frame  24 , thereby sealing door  20  to frame assembly  18 .  
         [0056]     It will be understood by those skilled in the art that door  20  can be provided with a hinge mechanism on any one of the top wall  50 , bottom wall  52  and one or the other of side walls  48  without departing from the spirit of the present invention. When door  20  is hinged differently, it can be opened upwardly, downwardly or to one of the left and right sides as is required by the chute system which it is designed to cover.  
         [0057]     The present invention may be embodied in other specific forms without departing from the spirit of the invention. The described embodiments are to be considered in all respect only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes within the meaning and range of equivalency of the claims are to be embraced within their scope.  
         [0058]     In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.  
         [0059]     Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.