Abstract:
A system for sealing one end of a first air duct with an adjacent overlapping end of a second air duct incorporates multiple sealing components. One of the sealing components interacts and activates another of the sealing components. One of the sealing components mechanically compressively elastically deforms another of the sealing components.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   N/A. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   N/A. 
   INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC (SEE 37 CFR 1.52(e)(5) AND MPEP 608.05 
   N/A. 
   BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   This invention pertains to duct systems. 
   More particularly, the invention pertains to a system for sealing one end of a first air duct with an adjacent overlapping end of a second air duct. 
   In a further respect, the invention pertains to an air duct sealing system of the type described which incorporates multiple sealing components. 
   In another respect the invention pertains to an air duct sealing system of the type described in which one of the pair of sealing components interacts with and is used to activate another of the sealing components. 
   In still a further respect, the invention pertains to an air duct sealing system of the type described in which each sealing component generates forces that improve the sealing action of another sealing component. 
   (2) Description of Related Art including information disclosed under 37 CFR 1.97 and 1.98. 
   Arcuate air ducts comprise ducts that include arcuate walls. Arcuate ducts have circular and oval cross sections. A portion of the wall of a duct can be flat, but if the duct also incorporates an arcuate wall, the duct is considered to be an oval duct. For example, the ends or sides of the walls of some ducts have an arcuate semicircular shape, semi-elliptical shape, or other arcuate shape while the wall sections intermediate such ends or sides are flat or substantially flat. Such ducts are considered oval ducts even though a portion of the wall of each such duct is flat. Air ducts are ordinarily used to transport air, but can be utilized to transport other gases or gas mixtures. 
   A common problem encountered in an air duct system is providing an effective seal at the points at which the end of one duct member overlaps or creates a function with the end of the next successive duct member. Creating an effective seal between the ends of arcuate duct members can be a particular problem because the surfaces that need to be sealed are arcuate and because the degree of curvature of duct surfaces can vary over short distances. 
   Accordingly, it would be highly desirable to provide an improved system for sealing the adjacent ends of arcuate ducts in an air duct system. 
   Therefore, it is a principal object of the instant invention to provide an improved duct system. 
   A further object of the invention is to provide an improved system for sealing the junctions at which the ends of adjacent ducts meet in an air duct system. 
   Another object of the invention is to provide an improved air duct sealing system that utilizes multiple seals at the junction of the ends of a pair of adjacent air ducts. 
   Still another object of the invention is to provide an improved air duct sealing system which utilizes interactive seals. 
   These and other, further and more specific objects and advantages of the invention will be apparent from the following detailed description of the invention, taken in conjunction with the drawings, in which: 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       FIG. 1  is a perspective view illustrating a duct system constructed in accordance with the principles of the invention; 
       FIG. 2  is an enlarged perspective view of a portion of the duct system of  FIG. 1  illustrating additional construction features thereof; 
       FIGS. 3A  to  3 C are side section views of the duct system of  FIGS. 1 and 2  illustrating the mode of operation thereof; 
       FIGS. 4A and 4B  are side section views illustrating the mode of operation of another embodiment of the duct system of the invention; 
       FIGS. 5A and 5B  are side section views illustrating the mode of operation of a further embodiment of the duct system of the invention; 
       FIGS. 6A and 6B  are side section views illustrating the mode of operation of still another embodiment of the duct system of the invention; and, 
       FIGS. 7A and 7B  are side section views illustrating the mode of operation of still a further embodiment of the duct system of the invention. 
   

   BRIEF DESCRIPTION OF THE INVENTION 
   Briefly, in accordance with my invention, I provide an improved hollow air duct member. The air duct member includes an arcuate wall; and, an end. The end includes an arcuate edge; an arcuate indent spaced apart from the arcuate edge and generally extending peripherally around the member; an elongate elastic member seated in the indent; and, a compression member seated in the indent and deformable to contact and generate compression forces against the elastic member. 
   In another embodiment of the invention, I provide an improved method of sealing an air duct system. The improved method includes the steps of providing a first hollow arcuate air duct with an overlap end; providing a second hollow arcuate air duct with an insert end; placing at least one elongate elastic member on one of the overlap and insert ends; placing at least one compression member on one of the overlap and insert ends, the compression member being deformable to contact and generate compression forces against the elastic member; and, inserting the insert end in the overlap end such that the compression member is compressed and deformed and contacts and generates compression forces against the elastic member. 
   DETAILED DESCRIPTION OF THE INVENTION 
   Turning now to the drawings, which depict the presently preferred embodiments of the invention for the purpose of illustrating the practice thereof and not by way of limitation of the scope of the invention, and in which like reference characters refer to corresponding elements throughout the several views,  FIGS. 1 and 2  illustrate a duct system including at least a first circular air duct  10  and a second circular air duct  12 . Air duct  10  includes end  11 . Duct  12  includes end  13 . As will be described, ends  11  and  13  are shaped and dimensioned such that end  11  is sealingly inserted in end  13 . 
   Duct  10  includes a cylindrical wall having a cylindrical outer surface  27  and a cylindrical inner surface  22 . Duct  12  includes a cylindrical wall having a cylindrical outer surface  26  and a cylindrical inner surface  21 . The diameter of the cylindrical walls of ducts  10  and  12  can vary somewhat, especially at ends  11  and  13  where indents  17  or collars  25  may be formed. Surfaces  22 ,  27 ,  21 ,  26  are, however generally cylindrical along the entire length of each duct  10  and  12 . 
   End  13  includes circular edge  15 . End  11  includes circular edge  14 . End  11  also includes outwardly extending peripheral collar  25  and peripheral depression or indent  17 . Indent  17  includes sloped surface  17 A (FIG.  3 A). Elastic O-ring  16  and spaced apart deformable members  18  to  20  are seated in indent  17 . Each deformable member  18  to  20  is attached to and outwardly depends from a cylindrical panel or collar  23  that is seated in and extends along indent  17 . If desired, members  18  to  20  can be interconnected and form a single continuous member that extends around end  11  with indent  17 . It is, however, presently preferred that members  18  to  20  be spaced apart in the manner shown. 
   Indent  17 , O-ring  16 , collar  25 , and members  18  to  20  presently each extend completely around the periphery of duct  10  in the manner illustrated in  FIGS. 1 and 2 . It may be desirable to extend indent  17 , O-ring  16 , collar  25 , and/or members  18  to  20  only partially around duct  10 . Or, it may be desirable to divide indent  17 , O-ring  16 , collar  25 , and members  18  to  20  into sections. For example, instead of having one continuous indent  17  extending completely around duct  10  it may be desirable to divide indent  17  into three spaced apart sections each of which extends only partially circumferentially around duct  10 . It is, however, presently preferred that indent  17 , O-ring  16 , collar  25 , and member  18  to  20  extend completely around the circumferential periphery of duct  10  in the manner shown in  FIGS. 1 and 2 . 
   Members  18  to  20  presently include spring portions  18 B,  19 B,  20 B, respectively. Each spring portion  18 B,  19 B,  20 B includes a foot  18 A,  19 A,  20 A, respectively. Portions  18 B,  19 B,  20 B need not comprise springs or some other elastic material, but must, as discussed below, be deformable such that feet  19 A to  20 A contact O-ring  16  and generate compressive forces against O-ring  16 . 
     FIGS. 3A ,  3 B,  3 C illustrate the mode of operation of the interactive sealing system of  FIGS. 1 and 2 . 
   In  FIG. 3A , end  13  of duct  12  is ready to be slid in the direction of arrow A over end  11  of duct  10 . 
   In  FIG. 3B , cylindrical duct  12  and end  13  have been partially slid in the direction of arrow A to a position in which edge  15  initially touches spring portion  20 A (and of course initially touches each other spring portion  18 A,  19 A, etc. shown in FIGS.  1  and  2 ). In order for edge  15  to reach the position shown in  FIG. 3B , edge  15  and a portion of end  13  are slid over and compress O-ring  16 . O-ring  16  is illustrated in a compressed state in FIG.  3 B. In  FIG. 3A , O-ring  16  has not been compressed. When O-ring  16  is being compressed by inner surface  21  of end  13 , foot  20 B functions to hold O-ring  16  in place against sloped surface  17 A. In the practice of the invention, it is not necessary that O-ring  16  be compressed by surface  21  when end  13  slides over O-ring  16 , but such compression is preferred because it produces a better seal. 
   After end  13  and edge  15  reach the position shown in  FIG. 3B , the displacement of cylindrical duct  12  and end  13  in the direction of arrow A is continued. The continued displacement of end  13  in the direction of arrow A forces edge  15  and a portion of end  13  over spring member  20 A and downwardly depresses member  20 A in the direction of arrow D ( FIG. 3B ) to the position illustrated in FIG.  3 C. Downwardly depressing member  20 A expands member  20 A by forcing foot  20 B in the direction of arrow B ( FIG. 3C ) away from collar  25  and against O-ring  16 . Before member  20 A is downwardly depressed in the direction of arrow D, it is not necessary that foot  20 B contact O-ring  16 . Foot  20 B can be spaced away from O-ring  16 . After, however, member  20 A is downwardly depressed to the position shown in  FIG. 3C , foot  20 B must at least contact O-ring  16  and preferably should generate compression forces against O-ring  16  that force O-ring  16  against sloped surface  17 A and against the inner surface  21  of end  13 . When foot  20  presses O-ring  16  against surface  17 A and surface  21 , the elasticity of O-ring generates opposing forces that attempt to press foot  20 B in a direction opposite that of arrow B. When foot  20 B is pressed in a direction that of arrow B, spring member  20 A is forced against inner surface  21 , improving the seal between member  20 A and end  13 . Consequently, O-ring  16  and member  20 A each interact with the other to improve and facilitate the seal created by the other. The resilient nature of spring member  20 A also generates forces against surface  21  that improve the seal between surface  21  and member  20 A. 
   The shape and dimension of O-ring  16  and the material used to construct O-ring  16  can vary as desired as long as O-ring  16  functions to be pressed by member  20 A against at least one surface  17 A,  21  on at least one of ends  11  and  13 . O-ring  16  need not, for example, be cylindrical and need not have a circular cross-section. 
   The shape and dimension of member  20 A and the material used to construct member  20 A can vary as desired as long as member  20 A functions to at least contact O-ring  16  when member  20 A is depressed in the direction of arrow D. Member  20 A also preferably, but not necessarily, generates compression forces against O-ring  16  when member  20 A is depressed in the direction of arrow D. 
     FIGS. 4A and 4B  illustrate an alternate embodiment of the interactive duct sealing system of the invention. In  FIGS. 4A and 4B , the construction of cylindrical duct  10 A is identical to that of duct  10  except that indent  17  is eliminated. The construction of cylindrical duct  12 A is identical to that of duct  12 , except that collar  30  has been incorporated in end  13 . Collar  30  includes inner sloped surface  30 A. Surface  30 A performs a function similar to that performed by surface  17 A in  FIGS. 3A and 3B . In operation of the embodiment of the invention shown in  FIG. 4A , when end  13  is displaced from the position shown in  FIG. 4A  in the direction of arrow C to the position shown in  FIG. 4B , the inner surface of end  13  compresses O-ring  16  and also downwardly depresses member  20 A in the direction of arrow E to the position illustrated in FIG.  4 B. In  FIG. 4B , foot  20 B is expanded away from collar  25  against O-ring  16  and forces O-ring  16  against the inner cylindrical surface  27 A of end  11 , against surface  30 A, and against surface  21 A. 
     FIGS. 5A and 5B  illustrate an alternate embodiment of the interactive duct sealing system of the invention. In  FIGS. 5A and 5B , end  13  of cylindrical duct  12 B has a structure that is basically identical to that of end  11  of duct  10 , except that the structure of end  13  in duct  12 B is inverted from the structure of end  11  of duct  10  and except that duct  12 B is the larger diameter duct (whereas duct  10  is the smaller diameter duct in FIG.  3 A); and, cylindrical duct  10 B has a structure that is basically identical to that of duct  12 , except that duct  10 B is the smaller diameter duct (where duct  12  is the larger diameter duct in FIG.  3 A). Consequently, collar  125  is comparable to collar  25 ; and, indent  117  and surface  117 A are comparable to indent  17  and surface  17 A. Member  120 A and collar  123  are comparable to member  20 A and collar  23  except that member  120 A, instead of facing outwardly in the manner of member  20 A, faces inwardly. When end  11  in  FIG. 5A  is displaced in the direction of arrow G to the position shown in  FIG. 5B , inner surface  27  depresses member  120 A in the direction of arrow H such that foot  120 B is moved away from collar  125  against O-ring  16  to force O-ring  16  against surface  117 A and surface  27 . 
     FIGS. 6A and 6B  illustrate an alternate embodiment of the interactive duct sealing system of the invention. In  FIGS. 6A and 6B , end  13  of cylindrical duct  12 C has a structure that is identical to that of end  13  of duct  12 A in  FIG. 4A , except that O-ring  16  is mounted on surface  30 A. In  FIGS. 6A and 6B , cylindrical duct  10 C has a structure that is basically identical to that of duct  110 B in  FIG. 5A , except that collar  23  is fixedly secured to the cylindrical wall of duct  10 C with rivets  32 . When end  11  in  FIG. 6A  is displaced in the direction of arrow J to the position shown in  FIG. 6B , inner surface  21  depresses member  20 A such that foot  20 B moves against O-ring  16  to force O-ring  16  against surfaces  27 ,  30 A,  21 . Surface  21  also compresses O-ring  16  against surface  27 . 
     FIGS. 7A and 7B  illustrate an alternate embodiment of the interactive duct sealing system of the invention. In  FIGS. 7A and 7B , end  13  of cylindrical duct  12 D has a structure that is identical to that of end  13  of duct  12  in  FIG. 3A , except that an elastic member  16 A is mounted on the inner surface  21  of end  13 . In  FIGS. 7A and 7B , cylindrical duct  10 D has a structure that is identical to that of duct  20 C (FIG.  6 A). When end  13  in  FIG. 7A  is displaced in the direction of arrow K to the position shown in  FIG. 7B , elastic member  16 A downwardly depresses member  20 A such that foot  20 B is moved away from rivet  32 . When member  20 A is downwardly depressed toward surface  27 , member  20 A contacts member  16 A and generates compressive forces against member  16 A.