Abstract:
Permits retrofit trash and linen chute inlet door replacement without destruction of existing B-Label wall/door frame assemblies and introduces advancements never before seen in the chute industry: Compliance to updated U.L.® Standards for B-Label doors, smoke suppression, and air tightness. The invention serves as the basis for a new U.L.® standard for certified retrofit installation of inlets. The inlet provides applicable ADA compliance. The latter results from several design features including a choice of four-access control/operating systems: mechanical, electronic, electro-pneumatic, and fully pneumatic. Each control system defaults a to the “Fail-Safe/Door-Closed” position in the event of component failure, thereby insuring the continued operation of the U.L.®/Life Safety features. Previous art fails in a “door open” position, destroying life safety functionality. Fail-Safe default is the basis of a proposed new NFPA-82 requirement.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   Please note that the title of this document has been simplified for ease of reference. This Non-Provisional Patent Application should be cross referenced with the previously submitted Provisional Patent Application: jc912 U.S. PTO 60/421,604 Dated Oct. 27, 2002, titled: 
   “AN AMERICANS&#39; WITH DISABILITIES ACT (ADA) COMPLIANT TRASH AND LINEN CHUTE INTAKE DOOR FOR RETROFIT &amp; NEW CONSTRUCTION ADDITIONALLY PROVIDING FOR SMOKE SUPPRESSION AND SUPERVISED ACCESS CONTROL” 

   STATEMENT OF FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
   Not Applicable 
   REFERENCE TO SEQUENCE LISTING 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
   The present invention relates to an improved inlet system for trash chutes, linen chutes, (and any appropriate synonym for either “trash” or “linen” or “chute”) and the like. 
   Trash and linen chutes are ubiquitous in new and existing residential and commercial buildings. They can also be found in hospitals, nursing homes, hotels and other facilities where relatively large amounts of trash and/or harmful waste are to be conveyed for disposal and/or treatment, whether by removal from the building, incineration, cleaning and/or recycling. Entry to a chute is made via one or more inlets, generally on each building floor. Such inlets are either bottom-hinged or side hinged, and open toward the user. 
   Building codes and other standards, including both U.L.® and the National Fire Protection Association (NFPA), typically require such trash and linen chutes, chute shafts and/or chute enclosures, (collectively, “chutes”) and the inlets that serve them (whether collectively constructed of metal, concrete, fire-rated wall board, masonry, and the like, or some combination thereof) to be designed and constructed to afford the protection of the fire-ratings specific to the characteristics of the installation, i.e., zoning, occupancy use/type, building height and area, etc. The fire rated protection affords Life Safety relief to building visitors, users, occupants and/or firefighters from the untoward consequences of fires and/or their accompanying smoke discharges when such conflagrations are sourced in the chute or at the base of the chute. The intended reliefs come in many forms, either singularly or in combination including but not limited to, fire containment, fire suppression, fire alarms, and exiting or other egress paths. Please see appropriate codes and standards presented on the next page: 
   
     
       
             
             
             
           
         
             
                 
             
             
               Code 
               Standards 
               Description 
             
             
                 
             
           
           
             
               NFPA 
                80 
               This is the National Fire Protection Association Chapter 80 prescribes 
             
             
                 
                 
               standards for gasketing materials used for air tightness to control noxious 
             
             
                 
                 
               gases or smoke. The Stage I Gasket is in compliance with this standard. 
             
             
                 
               105 
               Definitions for Ambient, Warm and Hot Smoke Characteristics. Used as the 
             
             
                 
                 
               basis for determining compliance with UL Air Tightness Standard, UL 1784. 
             
             
                 
                 
               The Stage II Gasket is in compliance with this standard. 
             
             
                 
                82 
               National Fire Protection Association Chapter 82 (NFPA-82) governs the 
             
             
                 
                 
               installation requirements for trash and linen chutes. The preferred 
             
             
                 
                 
               embodiment meets the existing criteria of this document, including the 
             
             
                 
                 
               standards pertinent to the ratios of effective opening and chute diameter for 
             
             
                 
                 
               trash and linen chutes, which are addressed by the preferred embodiment in 
             
             
                 
                 
               a completely new way. 
             
             
                 
               Fail-Safe 
               This is a proposed new standard to NFPA-82. All previous art experiences 
             
             
                 
               Closed 
               and demonstrates a chute intake door failure by presenting the following 
             
             
                 
               (Proposed 
               symptom: the malfunctioning door fails to close. This failure automatically 
             
             
                 
               New 
               negates the intent of the UL B-Label design of the door because the door no 
             
             
                 
               Standard) 
               longer closes nor positively latches as required by the UL 10-B, B-Label 
             
             
                 
                 
               Standard (a protected opening is designed to prevent the spread of fire 
             
             
                 
                 
               across the opening). The preferred embodiment is designed to correct this 
             
             
                 
                 
               deficiency by failing to open in the event of a malfunction, thereby 
             
             
                 
                 
               maintaining all the life safety features intended by the aforementioned UL 
             
             
                 
                 
               standard. This is the essence of the Fail-Safe Closed feature. This feature 
             
             
                 
                 
               exceeds the requirements of NFPA-82. 
             
             
               UL 
               10-C 
               Allows for application of negative and positive pressure to a 90-Min. B-Label 
             
             
                 
                 
               opening during fire conditions. Limits door deflection at the weakest point of 
             
             
                 
                 
               the span and seals against smoke transfer across the protected B-Label 
             
             
                 
                 
               opening. The Standard has never before been tested on a chute inlet door. 
             
             
                 
                 
               All existing art meets the 90-minute B-Label Standard 10-B or other, similar, 
             
             
                 
                 
               state-specified standards. Passing UL 10-C automatically includes passing 
             
             
                 
                 
               the 10-B standard. Passing the UL 10-B standard does not qualify for 10-C 
             
             
                 
                 
               approval. 
             
             
                 
               250 Deg. 
               Maximum allowable temperature rise over the first 30 minutes of the UL B- 
             
             
                 
               Maximum 
               Label fire test measured at the center of the door face on the side opposite 
             
             
                 
               Temp. 
               the flame. 
             
             
                 
               Rise 
             
             
                 
               over 30 
             
             
                 
               Minutes 
             
             
                 
               1784 
               Certification of Air Tightness. Never before applied to a chute intake door. 
             
             
                 
                 
               Designed to control transfer of odors and gases across door opening during 
             
             
                 
                 
               normal operation. The Stage II Gasket is in compliance with this standard. 
             
             
                 
               Retrofit 
               Proposed new UL Standard for certified retrofit installation of replacement 
             
             
                 
               Install- 
               door (All existing replacements void UL certifications by destroying the 
             
             
                 
               ation 
               originally designed assembly because the frame of the door must be 
             
             
                 
               (Proposed 
               removed from the wall (part of the UL 10-B, B-Label Assembly of wall + 90 
             
             
                 
               New 
               minute intake door designed to work in concert with one another to prevent 
             
             
                 
               Standard) 
               the transfer of fire across the protected opening). The preferred embodiment 
             
             
                 
                 
               overcomes this deficiency in the existing art by leaving the original frame 
             
             
                 
                 
               intact, thereby preserving and adding to the original assembly to maintain the 
             
             
                 
                 
               B-Label protection. Additionally added is the UL 10-C Standard related to 
             
             
                 
                 
               smoke control thru the use of intumescent materials designed and approved 
             
             
                 
                 
               for 10-C applications. The Stage II Gasket is in compliance with this 
             
             
                 
                 
               standard. 
             
             
                 
             
           
        
       
     
   
   Chute inlets typically provide containment through compliance with design features in accordance with Underwriters&#39; Laboratories (U.L.®) Standard 10B. U.L.® 10B stipulates the fire test criteria for approval of 90-minute, B-Label doors to function as part of a door-plus-firewall assembly in new constructions to permit containment. The “assembly” concept is extremely important because a “B-Label” door does not provide containment as a freestanding object. In order to provide containment, the B-Label door must be assembled in a firewall in a manner identical to the assembly that was fire tested by U.L.® in order to secure the U.L.® B-Label rating for the door. In some rare instances, certain chute inlet manufacturers only design to State criteria, often very similar to U.L.®, but in those instances, their door products can only be used in those States issuing the approvals. The purpose of those approvals, however, is very similar in intent: To provide Life Safety protection and relief to building visitors, users, occupants, and/or firefighters. 
   The chute industry (and those who govern it with codes, guidelines, standards, inspections, etc.) recognizes that a problem exists when an inlet door of prior art fails. Specifically, component failure in prior art is identified by the inability of the inlet to properly close and latch. Such failure results in the total suspension of the B-Label design approval characteristics of the inlet-firewall assembly, thereby nullifying the potential for containment of fire and/or smoke emanating from the chute. Such failure consequently exposes building visitors, users, occupants, firefighters, and the physical property itself, to the real and well documented potential for catastrophic destruction and/or death. 
   It is further recognized that the replacement of a failed inlet door generally involves the removal of the existing door and its frame. That removed frame is part of the aforementioned U.L.® approved inlet-firewall assembly, originally constructed to specific Life Safety codes and standards. Removal of the existing inlet frame and the installation of a new inlet door and frame permanently destroys the U.L.® approval criteria because replacement requires destruction of the original anchoring criteria specified in compliance with the originally approved U.L.® testing. In short, the replacement of a door to repair a door that no longer closes (a retrofit installation) is only a choice of the lesser of two evils, not the restoration of original conditions. 
   Beginning in the previous decade, residential and other buildings have additionally become subject to the progressively revised provisions of the Americans&#39; with Disabilities Act of 1990 (ADA). The mandatory compliance with this Federal law requiring Accessibility for existing buildings, such as apartment facilities and the like, requires the necessity of retrofit construction. The inherent problems of retrofit construction discussed in the previous paragraph are multiplied exponentially by this mandatory compliance. 
   
     
       
             
             
             
           
         
             
                 
             
             
               Code 
               Standards 
               Description 
             
             
                 
             
           
           
             
               ADA 
               Grab-Pinch- 
               ADA (The Americans&#39; with Disabilities Act) prohibits grabbing, pinching, or 
             
             
                 
               Twist 
               twisting and operating mechanism in order to effectuate the device action. 
             
             
                 
               Operating 
               ADA limits the maximum operating force required to operate an interior door 
             
             
                 
               Force 
               (without specificity to size) to five (5) pounds. 
             
             
               ADA 
               Grab-Pinch- 
               ADA (The Americans&#39; with Disabilities Act) prohibits grabbing, pinching, or 
             
             
                 
               Twist 
               twisting and operating mechanism in order to effectuate the device action. 
             
             
                 
               Operating 
               ADA limits the maximum operating force required to operate an interior door 
             
             
                 
               Force 
               (without specificity to size) to five (5) pounds. 
             
             
                 
               Mounting 
               The maximum allowable mounting height of the operating mechanisms of an 
             
             
                 
               Height 
               ADA compliant device is 54″ (side reach) or 48″ (front reach). 
             
             
                 
               Wall 
               The maximum allowable projection of an ADA compliant device is 4″ off the 
             
             
                 
               Projection 
               surface of the wall. 
             
             
                 
             
           
        
       
     
   
   Attempts by previous art to address accessibility issues fall short of fulfilling the original construction criteria as discussed in the preceding paragraphs [0007] and [0008]. This prior art also fails to insure that a damaged inlet will close in the event of component failure, if for no other reason than an open, bottom-hinged door that has experienced a gas cylinder, counterbalance-type-failure, cannot defy gravity in order to close itself. 
   Unauthorized or unsafe use of a chute inlet due to lack of access control can lead to serious injury or even death should a person injure themselves by falling. Small children and college students have been known to be among the unfortunate victims of such falls. 
   Prior art either ignores access control or makes it so expensive as to prohibit its use in many instances. 
   Prior art also falls short of protecting workers from the effects of potentially injurious repetitive movements prohibited for workers by the U.S. Occupational Safety and Health Act (OSHA). 
   
     
       
             
             
             
           
         
             
                 
             
             
               Code 
               Standard 
               Description 
             
             
                 
             
           
           
             
               OSHA 
               Repetitive 
               Repetitive manual activity can be injurious in the 
             
             
                 
               Action 
               work place. The use of the magnetic key fob 
             
             
                 
                 
               eliminates the need for using hands to operate the 
             
             
                 
                 
               inlet door. Waste materials can be disposed 
             
             
                 
                 
               of with a simple pushing action that can be 
             
             
                 
                 
               accomplished without the use of hands if necessary. 
             
             
                 
             
           
        
       
     
   
   U.S. Pat. No. 6,062,368 issued to Cluster P. Kamm on May 16, 2000 discloses a pull-out door having a rather complex arrangement of an electric motor, electric piston and cylinder lenses for moving the door, a switch means and control. Both the door swingable about a vertical axis and the operating mechanism are set within a frame-like box which can be unitarily installed, i.e. fixed within a pre-prepared opening in the wall housing the chute or the opening of the chute itself. 
   The disadvantages inherent in the device of U.S. Pat. No. 6,062,368 are many: 
   (a) It is fixed in size and cannot be readily retrofitted or adjusted to variances caused differences in construction; It has a complex operating mechanism which cannot be easily repaired or replaced and which is costly to manufacture; 
   (b) Although the patent emphasizes sanitary and health benefits there is no provision to seal the frame-like box in the chute opening to prevent feed back of waste and gases; 
   (c) The device of the patent employs a swing axis for the door by which the door swings outwardly into the path of the user inhibiting the efficient use of the system by the user. It is difficult to open when the user has both hands full. 
   (d) In the event of a door component failure, the door fails in a “door open” position, thereby negating the minimum, outdated Life Safety features offered. 
   (e) Access supervision is not provided, and 
   (f) The intake does not address OSHA requirements for the workplace. 
   In addition, various attempts have been made to provide non-automatic doors having a horizontal swing axis at the upper edge of the doors so that the door may close simply by falling. Refer to U.S. Pat. Nos. 1,108,1784; 1,297,360; 3,980,166; 4,339,998; and 4,694,947. 
   The patents, however, exhibit the same disadvantages as the aforementioned patent and above all, are not push-in. 
   BRIEF SUMMARY OF THE INVENTION 
   It is, therefore, an object of the present invention to provide a chute inlet door that overcomes the disadvantages and differences of the prior art. 
   It is another object of the present invention to provide a chute inlet door simple in construction and less costly than the prior art. 
   It is also an object of the present invention to provide an improved chute inlet door capable of being easily retrofitted to the chute and easily fitted thereto. 
   It is also an object to provide a chute inlet door having improved sanitary, health and Life Safety characteristics and which is fully sealed when closed, even in the event of door component failure. 
   It is also an object of the present invention to provide a chute inlet door having improved latch means. 
   It is an object of the present invention to provide a chute inlet door with inexpensive, supervised access control for all users, building occupants and workers, alike. 
   It is also an object of the present invention to improve Life Safety in buildings with chutes for visitors, users, occupants, and/or firefighters through compliance with the applicable provisions of the various laws, codes, standards, and guidelines afforded by U.L.®, and NFPA for both new and retrofit construction. In this regard the following synopsis of applicable provisions mentioned above is provided: 
   It is also an object of the present invention to improve Accessibility in buildings with chutes, whether of new or retrofit construction, through compliance with the applicable provisions of ADA. In this regard the following synopsis of applicable provisions mentioned above is provided: 
   It is yet another object of the present invention to improve work place safety in accordance with applicable OSHA standards. 
   These objects and advantages as well as others will be seen from the following application. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     In the Drawings: 
       FIG. 1  ( 1 / 14 ) is an exploded view of the inlet door sections and their physical interrelationships to the frame of the current invention. The view is from the rear. 
       FIG. 2  ( 2 / 14 ) is a table of the interrelationships of the inlet door sections, and the various components of those sections, in relationship to the code compliance design criteria (ADA, U.L.®, NFPA, and OSHA) to which inlet doors are subject and formed the basis of this invention. 
       FIG. 3  ( 3 / 14 ) is a front elevation of the trash/linen chute inlet door of the present invention. 
       FIG. 4  ( 4 / 14 ) is an elevation of the inlet door frame indicating the various components of the door, access control, assisted lift &amp; dampening, and dual latching systems all housed by the frame. 
       FIG. 5  ( 5 / 14 ) is an exploded view of the frame components that create the unique frame throat projection, component housings and inlet-surrounding construction-mating surfaces for the installation of Stage II gasketing for new and retrofit installations. Also called out are vertical Cross Sections A- 9 / 14  and A- 10 / 14 . 
       FIG. 6  ( 6 / 14 ) is a view from the rear of the door stop assembly components that create the Stage I gasket mounting surfaces through cooperation between the stop assembly and the top of the frame. 
       FIG. 7  ( 7 / 14 ) is a view of the interior structural components of the door frame and the assisted lift and dampening components that control the movement of the door. 
       FIG. 8  ( 8 / 14 ) is a view of the two-piece face panel components that create the exterior skin of the door and provide mounting surface for one application of the Stage II gaskets. 
       FIG. 9  ( 9 / 14 ) is the Section A- 9 / 14  called out in  FIG. 5 . This is the surface mounted, retrofit construction installation of the door indicating the Stage II gasketing between the rear of the frame and the mounting wall and the Stage I gasketing between the door stops and the front face of the inlet door. Also indicated is the rearward movement of the door swing. 
       FIG. 10  ( 10 / 14 ) is the Section A- 10 / 14  called out in  FIG. 5 . This is the flush mounted, new construction installation of the door indicating the Stage II gasketing between the rear of the frame and the mounting wall and the Stage I gasketing between the door stops and the front face of the inlet door. Also indicated is the rearward movement of the door swing. 
       FIG. 11  ( 11 / 14 ) includes details of a mechanical, dual-positive latching mechanism powered manually by pushing against the large paddle that can alternatively be mounted on the surface of the door. A key lock provides access control. This drawing also details the construction details of the Stage I gasket system. The gasket is shown in its compressed position of repose between the door stop and the front face of the inlet door. 
       FIG. 12  ( 12 / 14 ) is a schematic of the preferred dual, positive latching, electronic security/access control system. A complete version of the latching mechanism can be seen in  FIG. 4  that depicts the latching mechanisms ( 72 ) attached to the solenoids ( 73 ). 
       FIG. 13  ( 13 / 14 ) is a schematic of an alternative, a dual, positive latching, electro-pneumatic security/access control system. A complete version of the latching mechanism can be seen in  FIG. 4  that depicts the latching mechanisms ( 72 ) attached to the solenoids ( 73 ). 
       FIG. 14  is a schematic of an alternative, a dual positive latching, fully pneumatic security/access control system A complete version of the latching mechanism can be seen in  FIG. 4  that depicts the latching mechanisms ( 72 ) attached to the solenoids ( 73 ). Alternatively, the latch actuators can be mounted horizontally to project/retract directly into and out of the inlet door panel. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   This latest inlet is designed for compliance with the applicable provisions and requirements of ADA, U.L.®, and NFPA to achieve an inlet that is capable of retrofit installation. This current art is further designed for compliance with a new U.L.® Standard for B-Label Doors, UL 10C, which considers the effect of negative and positive pressures on doors and smoke control in a fire event. The current art is also designed to meet the criteria of UL 1784 for air tightness as an adjunct to the UL 10C criteria that also includes the control of ambient, warm and hot smoke as defined by NFPA-105, and is beyond the scope of the UL 10B approval for B-Label rated fire doors. UL 10C approval automatically achieves approval of UL 10B. UL 10B does not reach the UL 10C Standard, however. 
   With further regard to ADA, the current art meets the criteria for horizontal projection, mounting height of controls, the prohibition against grabbing, pinching or twisting of operational controls, and the criteria for opening and closing force of interior doors. 
   With regard to OSHA, the inlet complies with criteria designed to avoid repetitive actions in the workplace. 
   A particular use of the present invention is as the inlet door assembly for a trash chute  2  to feed a commercial/residential trash compactor or other trash room waste collection configuration. The inventive inlet may also be used in a variety of other installations as well, including commercial and institutional uses for linen collection. The embodiment shown in the drawings is illustrative and will amply exemplify the structure and details of the invention. 
   As seen in  FIG. 7  and  FIG. 8 , the several door panel components  31 ,  32 ,  33 ,  34 ,  41 ,  42  comprises a fireproof door panel  30 / 40  preferably having a front face  41  and rear face  42  between which is interposed a fire retardant insulation material  34  and a tray/frame  30  for the insulating material  34  that also acts to provide significant stiffness to the door  30 / 40  for purposes of enhanced structural integrity for durability against abuse and for added stiffness related to the desired level of fire rating under test conditions that might be imposed by Underwriters Laboratories (U.L.®) or the like. The inlet is set within a complimentary rectangular frame  10  also made of fire resistive materials like sheetmetal or a casting installed within a tight fitting opening in the wall  1  or within the framed opening  2  of a chute  3 . The wall  1  or chute  2  may be a new installation or an existing one. As will be seen, the invented inlet assembly may be used to refurnish existing buildings. The frame  10  extends outwardly from the wall  1  or chute  2  to define an aesthetic trim  100  for the door  30 / 40  and between which suitable Stage I gasketing  111  or Stage II gasketing  112  is placed so as to seal the door  30 / 40  during both normal operating conditions and during conditions of fire emergency. The frame  10  is bolted or otherwise secured to the wall by suitable fasteners  19  about its perimeter, and a bead of Stage II gasketing  112  or the like is inserted between the wall  1  and the existing chute frame  2 . 
   The door panel  30 / 40  is hinged with a 1″ diameter pipe  31  along its topmost edge to frame sides  15 ,  16  and set in oil-lite bushings  18 . In preference, the door panel  30 / 40  may be provided with several operating mechanisms depicted in  FIGS. 11 ,  12 ,  13 , and  14  that will be described separately, each of which has the following net effect: providing opening access operation that requires no grabbing, pinching or twisting as required for compliance with the provisions of the Americans with Disabilities Act of 1990, and/or its subsequent amendments, updates, modifications, etc.; providing dual, positive latching  72  for Life Safety and security issues; providing assisted lift  54  (either full or partial) to the upward travel (opening) of the door panel  30 / 40 ; providing dampened return  53  to the downward travel (closing) of the door panel  30 / 40 ; and to automatically bias the door panel  30 / 40  into its closed position where it bears against the pari-mutuel Stage I gasket  111  and centers on the latch bolts  72  to maintain the Life Safety design criteria features in normal use and especially as the default, fail-safe position in the event of an inlet component failure. 
   The supervised, security/access control operating systems depicted in  FIGS. 11 ,  12 ,  13 , and  14  include one of several options as may be dictated by the requirements of the new or retrofitted construction, and are as follow: 
   (a) A mechanical system of dual latches  72 , identified in  FIG. 11 , actuated manually by pressure against a panic bar-type device  61 , and protected from undesirable access by lock and key  62 ,  63 ; 
   (b) An electronic system of dual latches  72 , identified in  FIG. 12 , actuated by a secure access control switch  75  and magnetic fob  76  of any of several possible configurations and devices, including but not limited to, magnetic switches  75 ,  76 , card swipes, keypads, biological identifiers, or the like, etc., of any voltage and from any appropriate DC power system/source  77  or AC power source. Also utilized is an electronic timer  74  that activated by magnetic switches  75 ,  76  to send a signal to the DC power system/source  77  and to the solenoids  73  that retract for a settable timing sequence of up to ten seconds duration that release the dual latches  72  allowing use of the door panel  30 / 40  for as long as the user prefers. After the timing sequence ends, dual latches  72  are released by the solenoids  73  permitting the now extended dual latches  72  to await the return of the door panel  30 / 40  to its natural angle of repose against the stop assembly  20 . This alternate is considered best mode because of its simplicity of assembly and maintenance. 
   (c) An electro-pneumatic system of dual latches, identified in  FIG. 13 , actuated by a secure access control switch  75  and magnetic fob  76  of any of several possible configurations and devices, including but not limited to, magnetic switches  75 ,  76 , card swipes, keypads, biological identifiers, or the like, etc., of any voltage and from any appropriate DC power system/source  77  or AC power source, and utilizing a pneumatic cylinder/plunger  81  in conjunction with a flow control  83  and a regulator needle valve  82 , all of which are controlled by and electro-pneumatic timer  84  supplied with house compressed air supply  5  and a 24 volt DC power source  4  to provide action in accordance with that described in the previous paragraph with regard to the movement of the door panel  30 / 40 ; 
   (d) A fully pneumatic system of dual latches, identified in  FIG. 14 , actuated by keyed-palm button/switch  91 , timed by a pneumatic timer/sequencer  92  powered by a house compressed air supply  5 . Activation of the door panel  30 / 40  is by pneumatic cylinder/plunger  81  in conjunction with a flow control  83  and a regulator needle valve  82 , and occurs when the pancake latch/valves used in conjunction with regulator needle valve  82  and acting directly as the dual latch mechanism releases the door panel  30 / 40  for normal operation. This option may also be actuated by pneumatic switching source/device connected location, at any acceptable pressure required to power the system. 
   The novel construction of the frame  10 , trim  100  and the door panel  30 / 40  is shown in detail in  FIGS. 7 ,  8 ,  9 , and  10 . The inlet frame  10  is an assembly of sheet metal parts, preferably of aluminized steel, since such material can be bent, cut and shaped at relative ease. Sheetmetal is also light, and provides fire resistance. In he alternative, castings can be used. Simply, the frame consists of two side members  15 ,  16  reinforced by a vertical bracket/trim  17  bearing point at its forward end. The bodies of the side members  15 ,  16  are stepped down from the forward end to provide two levels to the frame, one to facilitate surface mounting of the embodiment, and the other to provide access to the throat of a chute  2  being retrofitted with this embodiment. The side members  15 ,  16  are spaced apart to form at the front an opening for the door panel  30 / 40  and at the rear a stop assembly  20  preventing the excess movement of the door panel  30 / 40  (15″×18″ is the most common trash door size, while other sizes up to 24″×24″ are fully possible with the current art. The opening at the front of the frame  10  in cooperation with trim  100  is designed to approximate the allowable effective opening of the door panel  30 / 40 , by code guideline/convention a proportional fraction of the diameter of the chute  2  being serviced by the inlet. The frame is covered at the top by a C-shaped form  11  fitting over the forward longer bezel. The rear-most leg of the C-shaped form is shortened laterally at each end, leaving a small overhang at one end and a larger overhang at its other end. A second, inverted C-shaped form  12  closes the side members  13 ,  14  at the bottom end  12 . The second channel member  12 , however, is different in that the foremost is shorter than its rear wall. The side members are further braced by a simple bracket fixed  17  to each side of the members  15 ,  16  and extended across the rear opening. Lastly the several parts are simply assembled by placing the parts together to form the frame assembly  10  shown in  FIG. 1  and the extending horizontal projection in to the chute  2  perpendicular to the wall  1  is folded over the adjacent corner and the main edges welded together. The perimeter adjoining edges of the welded frame  15 ,  16  and the required frame penetrations for control and other system needs are protected by intumescent caulk  113 , or the like to prevent the escape of fire or smoke in the event of a fire as an additional Life Safety feature of the embodiment. 
   As seen in  FIGS. 8 &amp; 9  the bottom of the inlet frame  10 , when assembled, provides a stop assembly  20  limiting the outward or return movement of the door panel  30 / 40  as it swings shut. The door panel  30 / 40  comes nearly flush with the edges of the frame opening and forms a seal against escape of he pollutants or fire or smoke, since this perimeter is provided with a Stage I gasket  111 . An additional, Stage II  112  gasket, mounted to the door panel  30 / 40  edges is provided to provide a permanent seal against gas/smoke escape in the event of a fire as an additional Life Safety feature of the embodiment. 
   The trim  100  can be of any of several colors or exposed metal decorative finishes, and can be embossed with any of several messages or logos. 
   The description of this preferred embodiment will likely give rise to suggested alternatives and modifications among those familiar with the industry and such products. It is therefore, the desire of this submission to include all such suggested alternatives and modifications as if they were herein incorporated in the scope of this preferred embodiment.