Emission-free exhaust pipe joint and clamp therefor

Abstract

The joint of the invention comprises exhaust pipes formed with beaded ends providing abutting flange-like surfaces that are axially forced together by a clamp applying wedging forces on the external beads. Modified forms of the joint have pilot extensions on one pipe of the joined pair, the bead on this one pipe in each case being spaced from the free end of the pipe. The pilot extension is telescoped within the other pipe bringing the beads together side by side and the clamp is engaged over both beads. In some joints, such as those formed in pipes made of a tough metal, a gasket may be inserted between the beaded ends. The clamp for the joints is one which has a concave groove engaging over the pair of beads to apply the axial force by the wedging action produced when the clamp is constricted. The preferred clamp is made in two halves which have a hinged connection of great simplicity comprising merely a rectangular bight formed on one end of one half and a tongue formed on one end of the second half. The tongue lies in the bight and cannot move laterally because of the self-centering action produced when the clamp is engaged on the beads. The other end of each half comprises a tongue with perforations aligned to receive a bolt and nut to enable the halves to be clamped together, pivoting with respect to one another on the hinged connection.

What is desired to be secured by Letters Patent of the United States is: 
     
       1. A clamped joint for use in internal combustion engine exhaust systems which comprises: A. a joint formed of a pair of pipes, each pipe having a bead formation at an end thereof, the bead formations including respective axially facing flange surfaces and the flange surfaces being substantially abutted face to face,   B. a pipe clamp engaged over the bead formations and constricted thereon, the clamp having radially inwardly facing groove means along its inner surface with opposite .[.surfaces.]. .Iadd.areas of said inner surface .Iaddend.of the groove means engaging the bead formations and applying wedging forces on said bead means causing the flange surfaces to be forced axially together,   C. the clamp being formed of two generally semi-circular halves, each half having a substantially radially outwardly extending tongue on one end thereof with the tongues spaced apart and having cooperating fastening means for bringing the tongues together in securing the clamp to the joint, each half having a medial section provided with said groove means, and the second end of each half having cooperating formations providing a separable hinge connection thereat,   D. said cooperating formations comprising an open bight on one of said second ends and a tab on the other of said second ends, the tab lying in the bight engaged against one side of said bight in surface engagement, .[.only.].,   E. said bight being generally rectangular in configuration and having a pair of planar portions spaced apart, one planar portion extending substantially radially outwardly of the clamp and the other being parallel thereto, a bridge connecting the planar portions, said other planar portion having a free end, the said tab extending substantially radially outwardly of the clamp and being disposed in facing engagement with the inside of said other planar portion,   F. said tongues having aligned perforations and said fastening means comprising a bolt extending through said perforations generally tangential to said clamp, one of said tongues having a right angle bent flange adapted to limit movement of the tongues toward one another.   
     
     
       2. A clamped joint for use in internal combustion engine exhaust systems which comprises: A. a joint formed of a pair of pipes, each pipe having a bead formation at an end thereof, the bead formations including respective axially facing flange surfaces and the flange surfaces being substantially abutted face to face,   B. a pipe clamp engaged over the bead formations and constricted thereon, the clamp having radially inwardly facing groove means along its inner surface with opposite .[.surfaces.]. .Iadd.areas of said inner surface .Iaddend.of the groove means engaging the bead formations and applying wedging forces on said bead means causing the flange surfaces to be forced axially together,   C. one pipe of said joint having its bead formation spaced from the free end of said one pipe whereby to form a pilot extension, said pilot extension being telescoped within the other pipe to bring the bead formations together,   D. the clamp being formed of two generally semi-circular halves, each half having a substantially radially outwardly extending tongue on one end thereof with the tongues spaced apart and having cooperating fastening means for bringing the tongues together in securing the clamp to the joint, each half having a medial section provided with said groove means, and the second end of each half having cooperating formations providing a separable hinge connection thereat,   E. said cooperating formations comprising an open bight on one of said second ends and a tab on the other of said second ends, the tab lying in the bight engaged against one side of said bight in surface engagement, .[.only.].,   F. said bight being generally rectangular in configuration and having a pair of planar portions spaced apart, one planar portion extending substantially radially outwardly of the clamp and the other being parallel thereto, a bridge connecting the planar portions, said other planar portion having a free end, the said tab extending substantially radially outwardly of the clamp and being disposed in facing engagement with the inside of said other planar portion,   G. said tongues having aligned perforations and said fastening means comprising a bolt extending through said perforations generally tangential to said clamp, one of said tongues having a right angle bent flange adapted to limit movement of the tongues toward one another.   
     
     
       3. A clamp for a pipe joint of the type which has a pair of side by side beads adapted to be forced against one another axially, said clamp comprising: A. a pair of independent generally semi-circular halves,   B. each half having a first end and a second end and a medial section between the ends, the medial section having a generally arcuate cross-section to form inner groove means adapted to be engaged upon the side by side beads,   C. a generally radially extending tongue on each first end, the tongues being spaced apart and having cooperating fastening means associated therewith to bring the tongues together in constricting the clamp,   D. the second ends having cooperating formations providing a .[.separable.]. hinge joint thereat,   E. said cooperating formations comprising an open bight on one of said second ends and a tab on the other of said second ends, the tab lying in the bight engaged against one side of the bight in surface engagement only,   F. said bight being generally rectangular in configuration and having a pair of planar portions spaced apart, one planar portion extending substantially radially outwardly of the clamp and the other being parallel thereto, a bridge connecting the planar portions, said other planar portion having a free end, the said tab extending substantially radially outwardly of the clamp and being disposed in facing engagement with the inside of the said other planar portion,   G. one of said tongues having a right angle bent flange directed toward the other tongue and adapted to limit movement of the tongues toward one another.   
     
     
       4. The clamp as claimed in claim 3 in which said tongues have aligned perforations and said fastening means comprise a bolt extending through said perforations generally tangential to said clamp. 
     
     
       5. A clamped joint comprising: A. a pair of pipes, each pipe having a rolled end forming a beaded formation directly thereon at an end thereof, .Iadd.each .Iaddend.said beaded formation .[.each.]. including .[.respective.]. .Iadd.an .Iaddend.axially facing flange surface, said flange surfaces being substantially abutted in face-to-face contact, and   B. a pipe clamp formed of two generally semi-circular bands each formed of a single piece and each having a semi-circular medial portion and two end portions extending respectively outwardly from said medial portion, .Iadd.there being a first end portion of each respective medial portion juxtaposed relative to one another and located on one lateral side of the clamp and a second end portion of each respective medial portion juxtaposed relative to one another and located on the side diametrically opposite said lateral side of said clamp, the said first end portions comprise substantially radially outwardly extending tongues with the tongues spaced apart and having cooperating fastening means for bringing the tongues together and securing the clamp to the joint, one of the tongues having a right angle bent flange directed toward the other tongue and adapted to limit movement of the tongues toward one another, and the second end portions of each semi-circular band having cooperating formations providing a hinge connection thereat in which said cooperating formations comprise an open bite on one of said second ends and a tab on the other of said second ends, the tab lying in the bite engaged against one side of said bite, said bite being generally rectangular in configuration and having a pair of planar portions spaced apart, one planar portion extending substantially radially outwardly of the clamp and the other being parallel thereto, a bridge connecting the planar portions, said other planar portion having a free end, the said tab extending substantially radially outwardly of the clamp and being disposed in facing engagement with the inside of said other planar portion, .Iaddend.the medial portion of each band having an arcuate cross-section and radially inwardly facing groove means along its inner surface with opposite areas of said inner surface of said groove means engaging the beaded formation and forming wedge elements tangentially engaging the respective surfaces of the rolled ends forming said beaded formations to apply wedging forces thereto to force the flange surfaces axially together, and fastening means cooperating with said respective end portions of said two semi-circular bands to secure the two semi-circular bands in tight fitting engagement over said beaded formations.   
     
     
       6. The clamped joint as claimed in claim 5 in which one pipe of the joint has its beaded formation spaced from the free end of said one pipe whereby to form a pilot extension, said pilot extension being telescoped within the other pipe to bring the beaded formations together. 
     
     
       7. The clamped joint as claimed in claim 6 in which the pipes are of the same outer and inner diameters and the pilot extension is formed as a smaller diameter neck to enable its outer diameter to engage within the other pipe. 
     
     
       8. The clamped joint as claimed in claim 6 in which the pipe having the pilot extension is of an outer diameter substantially the same as the inner diameter of the other pipe.  .[.9. The clamped joint as claimed in claim 5 in which each said semi-circular band has a substantially radially outwardly extending tongue on one end thereof with the tongues spaced apart and having cooperating fastening means for bringing the tongues together in securing the clamp to the joint, each semi-circular band having a medial section provide with said groove means, and the second end of each semi-circular band having cooperating formations providing a hinge connection thereat..]. .[.10. The clamped joint as claimed in claim 9 in which said cooperating formations comprise an open bight on one of said second ends and a tab on the other of said second ends, the tab lying in the bight engaged against one side of said bight in surface engagement only..].  .[.11. The clamped joint as claimed in claim 10 in which said bight is generally rectangular in configuration and has a pair of planar portions spaced apart, one planar portion extending substantially radially outwardly of the clamp and the other being parallel thereto, a bridge connecting the planar portions, said other planar portion having a free end, the said tab extending substantially radially outwardly of the clamp and being disposed in facing engagement with the inside of said other planar portion..]..Iadd. 12. The clamp as claimed in claim 3 in which the hinge joint is separable. .Iaddend. .Iadd. 13. The clamped joint as claimed in claim 5 in which there is an annular gasket sandwiched between said beaded formations. .Iaddend. .Iadd. 14. A clamped joint comprising: A. a pair of pipes, each pipe having a rolled end formation in the general configuration of an annular bead and each bead having an axially facing annular surface, at least one bead being generally arcuate in cross-section, the annular surfaces being engaged to one another in surface-toward-surface relationship so that the beads are substantially side by side,   B. a pipe clamp formed of two generally semi-circular integral metal bands to provide independently fabricated clamp halves, each half including a semi-circular medial portion having first and second end portions extending generally radially outwardly from the said medial portion, the halves being assembled onto the pipes with the medial portions forming a circular loop surrounding said beads and the first end portions juxtaposed relative to one another on one lateral side of the loop while the second end portions are juxtaposed relative to one another on the side diametrically opposite said one lateral side of the loop, the medial portion of each band having an arcuate cross-section providing a radially concave groove on its interior with the surfaces of the groove engaging each annular bead on circular areas generally coaxial with the pipes, the circular area of engagement of each bead being spaced from its engagement with the other bead and being at an angular relationship whereby to apply wedging forces during construction of the loop tending to force the axially facing annular surfaces of the beads towards one another, a generally radially extending tongue on each first end portion, the tongues being spaced apart and having cooperating fastening means associated therewith to bring the tongues together in constricting the clamp, the said second end portions having cooperating formations providing a hinge joint thereat, said cooperating formations comprising an open bight on one of said second ends and a tab on the other of said second ends, the tab lying in the bight engaged against one side of the bight in surface engagement only, said bight being generally rectangular in configuration and having a pair of planar portions spaced apart, one planar portion extending substantially radially outwardly of the clamp and the other being parallel thereto, a bridge connecting the planar portions, said other planar portion having a free end, the said tab extending substantially radially outwardly of the clamp and being disposed in facing engagement with the inside of the said other planar portion, one of said tongues having a right angle bent flange directed toward the other tongue and adapted to limit movement of the tongues toward one another, and the first end portions having fastening means cooperating therewith to secure the halves in tight-fitting engagement over said beads when side by side. .Iaddend. .Iadd. 15. The clamped joint as claimed in claim 14 in which the hinge means are manipulable to enable separation of said second ends. .Iaddend..Iadd. 16. The clamped joint as claimed in claim 14 in which said beads are both arcuate in cross section. .Iaddend..Iadd. 17. The clamped joint as claimed in claim 14 in which the beads are formed on the axial ends of the pipes. .Iaddend. .Iadd. 18. The clamped joint as claimed in claim 14 in which the bead of one pipe is formed spaced from its axial end, and that axial end is engaged telescopically within the other pipe to bring the beads together. .Iaddend..Iadd. 19. The clamped joint as claimed in claim 14 in which the fastening means comprise a threaded bolt passing through the first ends and securing them to one another. .Iaddend..Iadd. 20. The clamped joint as claimed in claim 14 in which there is an annular gasket sandwiched between the annular surfaces. .Iaddend.