Elbow connector and method of forming it

Claim 2

A sheet metal elbow connector having a substantially constant cross-sectional area along its length, comprising: a. a single substantially rectangular sheet of metal formed into a tubular conduit open at first and second opposite ends and having a longitudinally extending seam where side portions of said sheet are overlapped and secured together, said conduit having first and second end regions near said first and second ends and an intermediate region between said end regions; b. said conduit being formed into an elbow by forming a series of closely spaced perimetrically extending crimps in said intermediate region to define an elbow bend having a short inner radius of curvature with said seam extending along the outer radius of curvature, said elbow bend having a generally oval cross-section with a substantially constant cross-sectional area along its length; c. said first end region defining a substantially smooth-walled tube having substantially said constant cross-sectional area along its length as it extends from said intermediate region to said first end; d. said second end region having a pair of substantially V-shaped notches formed in opposite sides at locations disposed substantially 90* aRound the periphery of said end region from the location of said seam, and having portions which define said notches positioned in overlapping relationship and secured together to form a pair of side seams which cause the perimeter of said second end region to diminish as said second end region extends away from said intermediate region while the crosssectional area of said second end region remains substantially equal to said constant cross-sectional area as said second end region extends along its length from said intermediate region to said second end, said second end having a substantially round configuration with a cross-sectional area substantially equal to said constant cross-sectional area, whereby said second end region forms a substantially smooth-walled tubular transition between said substantially oval cross-section of said intermediate region and said substantially round configuration of said second end; and, e. a sheet metal band secured to said second end region near said second end, said band defining a round tube which extends away from said second end region and which has a cross-sectional area substantially equal to said constant cross-sectional area to enable connection of said second end region to a round sheet metal conduit having a cross-section area substantially equal to said constant cross-sectional area.

Claim 3

The sheet metal elbow connector of claim 1 wherein said portions which define said V-shaped notches and which are positioned in overlapping relationship are secured together by rivets extending through aligned apertures formed in overlapping ones of said portions.

Claim 4

The sheet metal elbow connector of claim 1 wherein said sheet metal band is secured to said second end region by crimping said band and said second end region to form mating perimetrically extending formations.

Claim 5

The sheet metal elbow connector of claim 1 wherein said V-shaped notches are relieved near said second end such that when said portions are positioned in overlapping relationship, no overlap is provided for a short distance along said notches immediately adjacent said second end, whereby said second end is defined along its perimeter by a single thickness of sheet metal, and, said sheet metal band is secured to said single thickness of sheet metal.

Claim 6

A round to oval elbow connector formed from sheet metal and having a substantially constant cross-sectional area along its length, comprising: a. a single substantially rectangular sheet of metal formed into a tubular conduit open at first and second opposite ends and having a longitudinally extending seam where side portions of said sheet are overlapped and secured together, said conduit having first and second end regions near said first and second ends and an intermediate region between said end regions; b. said conduit being formed into an elbow by forming a series of closely spaced perimetrically extending crimps in said intermediate region to define an elbow bend having a short inner radius of curvature with said seam extending along the outer radius of curvature, said elbow bend having a generally oval cross-section with a substantially constant cross-sectional area along its length; c. said first end region defining a tube of substantially oval cross-section and having substantially said constant cross-sectional area along its length as it extends from said intermediate region to said first end, whereby said second end region forms a substantially smooth-walled tube connectable to a conduit of oval cross-section having a cross-sectional area substantially equal to said constant cross-sectional area; d. said second end region having a pair of substantially V-shaped notches formed in opposite sides at locations disposed substantially 90* around the periphery of said end region from the location of said seam, and having portions which define said notches positioned in overlapping relationship and secured together to form a pair of side seams which cause the perimeter of said second end region to diminish as said second end region extends away from said intermediate region while the cross-sectional area of said second end region remains substantially equal to said constant cross-sectional area as said second end region extends along its length from said intermediate region to said second end, said second end having a substantially round configuration with a cross-sectional area substantially equal to said constant cross-sectional area, whereby said second end region forms a substantially smooth-walled tubular transition between said substantially oval cross-section of said intermediate region and said substantially round configuration of said second end; and, e. a sheet metal band secured to said second end region near said second end, said band defining a round tube which extends away from said second end region and which has a cross-sectional area substantially equal to said constant cross-sectional area to enable connection of said second end region to a round sheet metal conduit having a cross-sectional area substantially equal to said constant cross-sectional area.

Claim 7

A round to oval elbow connector formed from sheet metal and having a substantially constant cross-sectional area along its length, comprising: a. a single substantially rectangular sheet of metal formed into a tubular conduit open at first and second opposite ends and having a longitudinally extending seam where side portions of said sheet are overlapped and secured together, said conduit having first and second end regions near said first and second ends and an intermediate region between said end regions; b. said conduit being formed into an elbow by forming a series of closely spaced perimetrically extending crimps in said intermediate region to define an elbow bend having a short inner radius of curvature with said seam extending along the outer radius of curvature, said elbow bend having a generally oval cross-section with a substantially constant cross-sectional area along its length; c. said first end region defining a tube of substantially oval cross-section and having substantially said constant cross-sectional area along its length as it extends from said intermediate region to said first end, whereby said second end region forms a substantially smooth-walled tube connectable to a conduit of oval cross-section having a cross-sectional area substantially equal to said constant cross-sectional area; d. said second end region having a pair of substantially V-shaped notches formed in opposite sides at locations disposed substantially 90* around the periphery of said end region from the location of said seam, and having portions which define said notches positioned in overlapping relationship and secured together to form a pair of side seams which cause the perimeter of said second end region to diminish as said second end region extends away from said intermediate region while the cross-sectional area of said second end region remains substantially equal to said constant cross-sectional area as said second end region extends along its length from said intermediate region to said second end, said second end having a substantially round configuration with a cross-sectional area substantially equal to said constant cross-sectional area, whereby said second end region forms a substantially smooth-walled tubular transition between said substantially oval cross-section of said intermediate region and said substantially round configuration of said second end; and, e. a sheet metal band secured to said second end region near said second end, said band defining a round tube which extends away from said second end region and which has a cross-sectional area substantially equal to said constant cross-sectional area to enable connection of said second end region to a round sheet metal conduit having a cross-sectional area substantially equal to said constant cross-sectional area.

Claim 8

The sheet metal elbow connector of claim 5 wherein said portions which define said V-shaped notches and which are positioned in overlapping relationship are secured together by rivets extending through aligned apertures formed in overlapping ones of said portions.

Claim 9

The sheet metal elbow connector of claim 5 wherein said sheet metal band is secured to said second end region by crimping said band and said second end region to form mating perimetrically extending formations.

Claim 10

The sheet metal elbow connector of claim 5 wherein said V-shaped notches are relieved near said second end such that when said portions are positioned in overlapping relationship, no overlap is provided for a short distance along said notches immediately adjacent said second end, whereby said second end is defined along its perimeter by a single thickness of sheet metal, and, said sheet metal band is secured to said single thickness of sheet metal.