Exhaust system connector seal

Abstract

A method and apparatus for joining two tubular members in a strong, leak-proof fashion in which a band of ductile metal is passed around the adjacent ends of the members and circumferentially stressed beyond its elastic limit to conform intimately with the outer surfaces of the members throughout practically their entire circumstances. Several constructions for applying the circumferential forces are disclosed, and use is taught of a packing element to prevent paraxial or helical leakage.

What is claimed is: 
     
       1. The method of joining two substantially incompressible tubular members axially which comprises bending a flat band of ductile metal around the adjacent ends of the members in direct superficial contact with said members and circumferentially stressing the band beyond its elastic limit to cause it to conform to the surfaces of the members throughout substantially their entire circumference the ductile metal band being such that it yields before the material of said member. 
     
     
       2. The method of claim 1 in which the members are of slightly different diameters. 
     
     
       3. The method of claim 2 in which one of the members is telescopically received within the other. 
     
     
       4. The method of claim 1 in which one of the tubular members is a flexible metallic hose, and the circumferential forces are sufficient to perceptibly mold the band into the hose configuration. 
     
     
       5. The method of claim 1 with the further step of retaining said band in a stressed condition past the elastic limit of a metal. 
     
     
       6. In combination: a pair of substantially incompressible tubular members of generally the same outside diameter to be joined in end to end relation;   a band ductile metal initially of strip form having end portions and bent to circular shape whereby the end portions confront one another; said band surrounding the joint between said members, the width of said band being generally the same as the diameters of said members, and a substantial portion of the width of said band engaging each of said members in direct contact therewith;   and means circumferentially stressing said band beyond its elastic limit, whereby to draw the band into intimate sealing engagement with the outer surfaces of said members, and maintaining said engagement when achieved, the ductile metal band being such that it yields before the material of said members.   
     
     
       7. The structure of claim 6 in which the last named means includes a pair of reinforced flat ribs integral in part with said band and forming dihedral angles therewith, and clamping means mechanically drawing said ribs into mutual flat contact in a plane containing the axes of said members, whereby to produce the circumferential stress in said band, the length of said band between said ribs being less than the circumferences of said members, so that when the clamping means are tightened said band is stressed beyond its elastic limit and deforms into intimate superficial engagement with the member. 
     
     
       8. Apparatus according to claim 7 in which each of said ribs includes a bar secured to an end of said band and provided with bores adapted to be brought into alignment for receiving said clamping member. 
     
     
       9. Apparatus according to claim 8 in which said bar and said band are joined by spot welding along a line between the dihedral angle and said bores. 
     
     
       10. Apparatus according to claim 7 in which the apices of said dihedral angles are oblique with respect to the center line of said band. 
     
     
       11. Apparatus according to claim 8 in which at least one of said bars includes transverse slots between said bores to permit deformation of said bar to accommodate tubular members of somewhat different diameters. 
     
     
       12. Apparatus according to claim 9 in which at least one end of said band is doubled on itself prior to the formation of the dihedral angle, and in which the weld spots traverse both thicknesses of said band and extend along a line outside said bores. 
     
     
       13. Apparatus according to claim 12 in which the end of said band after doubling is welded to the body of the band. 
     
     
       14. Apparatus according to claim 8 in which one of said bars includes a pair of lateral extensions through which said bores pass to prevent cocking of said bar with respect to said clamping means, said bores in said one bar being of the same diameter as said clamping means, and said bores in the other bar being larger than said clamping means. 
     
     
       15. Apparatus according to claim 8 in which at least one end of said band is wrapped around the associated bar for traversal by said clamp means, of both layers of said wrap, both of said layers being spot welded to the bar along a line between the dihedral angle and said bores. 
     
     
       16. Apparatus according to claim 7 in which one of said tubular members is of somewhat larger diameter than the other, and approximately one-third the width of said band overlies the larger of said members. .Iadd. 17. Apparatus for connecting and sealing telescoped exhaust tubes comprising, in combination: a pair of substantially incompressible exhaust tubes of different diameter telescopically joined in end-to-end relation;   a band of ductile metal initially of strip form having end portions and bent to circular shape whereby the ended portions confront one another, said band surrounding the telescoped joint between the tubes, with a substantial portion of the width of said band engaging each of said tubes in direct contact therewith;   a pair of flat reinforced ribs integral in part with said end portions, said ribs being provided with bores adapted to be brought into alignment, the length of said band between said ribs being less than the circumference of the smaller of said tubes; and   clamping means extending through said bores, mechanically drawing said ribs into mutual flat contact, and circumferentially stressing said band beyond its elastic limit to deform said band into intimate superficial sealing engagement with both of said tubes as said clamping means are tightened, and to maintain said engagement when achieved, the ductile metal band being such that it yields before the material of said tubes. .Iaddend..Iadd. 18. Apparatus for producing and maintaining tight telescoped joints in exhaust tubes comprising, in combination:   a first tube of thickness to resist collapsing under compression and having an outside diameter of predetermined size;   a second tube having an inside diameter of substantially said predetermined size, telescopically receiving one end of said first tube;   a band of ductile sheet metal of width comparable with said predetermined size, said band including end portions, and a center portion surrounding the juncture between the telescoped tubes, with a substantial part of the width of the band engaging the outer surface of each of said tubes in direct contact therewith, and with said end portions extending in generally the same direction from said tubes in generally parallel relation;   a pair of flat ribs extending transversely of said band and integral in part with said end portions, each of said ribs including a transversely rigid reinforcing bar secured to one of said end portions, and of thickness large with respect to that of said band, said ribs being provided with bores adapted to be brought into alignment when said end portions are in said generally parallel relation, the length of said band between said end portions being less than the circumference of said first tube; and   clamping means extending through said bores for mechanically drawing said ribs into mutual flat contact when tightened, the gauge and ductility of said metal being such that the band is stressed circumferentially beyond its elastic limit, but not ruptured, without crushing said first tube, and is deformed into and maintained in intimate superficial sealing engagement with both said tubes, as said clamping means is tightened. .Iaddend.   
     
     
        .Iadd. 19.  An exhaust system joint comprising, in combination: an inner tube, of thickness to resist collapsing under compression, having an outside diameter of predetermined size;   an outer tube coaxial therewith and having an inside diameter of substantially said predetermined size, one end of said outer tube surrounding an end of said inner tube in telescoped relation;   a clamping band, for completing and maintaining a tight joint between said tubes by stress-deformation about the juncture of said tubes, and having a central portion of width comparable to the diameter of said tubes and first and second end portions spaced apart along the band by a distance less than the circumference of said inner tube;   said band comprising a strip of stress-deformable stainless steel extending from end to end therefrom, for bending closely around the juncture of said tubes into a position in which said end portions extend generally radially outward in the same direction from said tubes in spaced generally parallel relation;   each of said end portions having a flat transversely rigid bar extending across and secured to an end of said strip, and at least partially enwrapped thereby, spaced bores extending perpendicularly through said bar and said strip, the bores in the two end portions being similarly spaced and positioned so that they can be brought into alignment when the strip is returned on itself to bring said end portions into said generally parallel relation, and a portion at one edge of each bar being cut away to facilitate drawing the portion of the strip between said end portions into engagement with said tubes;   and clamping means extending through said bores for mechanically drawing said end portions into mutual flat contact when tightened, the gauge and ductility of said stainless steel being such that the band is stressed circumferentially beyond its elastic limit, but not ruptured, and is deformed into and maintained in intimate superficial engagement with both said tubes, as said clamping means is tightened. .Iaddend.