Patent Application
20100180509
The invention relates to an in-line access door, and more particularly, to an in-line access door having an outer door and releaseable fasteners for attaching the outer door in a fixed position relative to the duct.
It often is desirable to have easy access to various different types of ductwork. For example, prior to the installation of the ductwork, it may necessary to install fire system equipment or nozzles and install or reset dampers on the interior of the ductwork. However, once the ductwork has been installed at a site, it may be advantageous to install these access panels after other mechanical and/or electrical equipment has been installed so that areas chosen for the installation of the access panels will least interfere with opening of the access panels and/or will be the best location based on intended use and application.
Additionally, it may be difficult, if not impossible, to access the interior of the ductwork without cutting a hole in the ductwork or otherwise breaching the integrity of the duct wall after the ductwork has been installed. It especially is desirable to be able to access the interior of ductwork used as exhaust ducts so as to be able to remove any buildup on the interior surfaces of the duct wall.
For ductwork used as exhaust or grease ducts serving commercial and institutional kitchens, flammable byproducts, such as grease, may attach to the interior surface of the ducts. This grease buildup often is flammable and grease fires within the exhaust ductwork can be a common occurrence. In order to clean and inspect or to maintain equipment which may possibly be located within the duct, various building and safety codes require a certain number of access ports in the ductwork in order to be able to both clean out the ductwork and to combat any grease fires which may occur in the ductwork.
Access doors are installed at the end of a “snout” extending out from the duct which limits the location in which they can be installed due to the larger amount of space required. Access ports can be created by cutting out a portion of the ductwork or the duct wall so as to allow access to the interior of the duct, and then screwing or otherwise attaching a coverplate over the port. Such access ports often employ numerous fasteners which may require removal and replacement through the use of handtools. However, often such cut-and-cover access ports are not sufficiently well-built so as to survive a fire, that is, are not structurally safe, or to prevent flames and or vapors and gases from escaping from between the cover and the duct wall.
Representative of the art is U.S. Pat. No. 5,165,189 which discloses a An access door assembly for allowing access to the interior of a duct, including a mounting and support frame mounted at a selected location on the duct where an access port previously has been created in the duct, a cover releasably secured to the mounting and support frame by securing means, and a seal interposed between the cover and the mounting and support frame to prevent communication between the interior of the duct and the ambient when the cover is mounted on the frame.
The prior art doors comprise features desirable for relatively permanent attachment when the duct is not otherwise being accessed. This can involve significant time to remove the access door.
What is needed is an in-line access door having an outer door and releaseable fasteners for attaching the outer door in a fixed position relative to the duct. The present invention meets this need.
The primary aspect of the invention is to provide an in-line access door having an outer door and releaseable fasteners for attaching the outer door in a fixed position relative to the duct.
Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings.
The invention comprises an in-line access door comprising an inner door for covering and sealing a duct opening, the inner door comprising a hole for receiving a fastener, the fastener engageable with a stud, the stud fixedly attached to the duct, an outer door, a releasable snap fastener for attaching the outer door in a fixed position relative to the duct, an insulating member disposed between the inner door and the outer door, and a gasket disposed between the inner door and the duct for sealing the joint between the inner door and the duct.
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with a description, serve to explain the principles of the invention.
An inner door 11 covers the opening 12. Fasteners 14 are used to install door 11 over opening 12. Fasteners 14 engage studs 13. Studs 13 are disposed about an outer perimeter of opening 12. Studs 13 engage door 11 through slots or holes 16. One can see that the in-line access door is installed directly on the duct and does not require a “snout” or other connective member by which the access door is attached to the duct.
Handle 15 allows ease of handling door 11.
An opening 120 in lagging 41 and insulation 40 allows access to the duct 10.
Although a form of the invention has been described herein, it will be obvious to those skilled in the art that variations may be made in the construction and relation of parts without departing from the spirit and scope of the invention described herein.
