Pipe coupling with deformable outer sleeve

• US 3,905,623 A
• Filed: 04/05/1974
• Issued: 09/16/1975
• Est. Priority Date: 04/05/1974
• Status: Expired due to Term

• Current Assignee: Thomas R. Cassel
• Original Assignee: Thomas R. Cassel
• Inventors: Cassel, Thomas R.
• Primary Examiner(s): Kundrat, Andrew V.
• Application Number:
  US05/458,158
• Time in Patent Office: 529 Days
• Field of Search: 285/252,253,369,373,417,419,420,407,236,382.2,382.5,382 24/280,279
• US Class Current: 285/382
• CPC Class Codes: E02B 11/005 Drainage conduits
• CPC Class Codes: E03F 3/04 Pipes or fittings specially adapted to sewers manufacture of concrete tubes B28; pipes or pipe fittings in general F16L
• CPC Class Codes: F01N 13/1805 Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body pipe joints in general F16L; fixing auxiliaries in motor vehicles in general B60K
• CPC Class Codes: F16L 21/002 Sleeves or nipples for pipes of the same diameter; Reduction pieces with elastic sealing rings F16L21/022
• CPC Class Codes: F16L 21/065 tightened by tangentially-arranged threaded pins

Abstract

A pipe coupling is disclosed which utilizes a deformable outer sleeve or pipe which is adapted to be stretched about an inner pipe. The outer sleeve or pipe is formed with a portion of circular or roundish cross-section and a portion defining an inwardly opening, axially extending channel. The inner pipe includes a portion of circular or roundish cross-section and a portion, either integral with or separate from the wall of the inner pipe, which defines an axially extending spline. The inner pipe, including the spline, fits loosely inside the outer pipe with the spline in the channel. Fastener means extending through the wall of the channel draws the wall of the channel into engagement with the spline and stretches the outer pipe around the inner pipe to provide a strong mechanical joint and a fluid tight connection.

Claims

1. In a pipe coupling of the type comprising an outer pipe and an inner pipe extending into one end portion of the outer pipe, an end portion of the inner pipe having a peripheral length on the outer surface which is greater than the peripheral length of the opposed inner surface on the end portion of the outer pipe, force applying means adapted to act between the pipe ends for deforming the outer pipe end to change the cross-sectional dimensions thereof and produce a close fitting engagement with the inner pipe end wherein the inner pipe end is in compressive stress and the outer pipe end is in tensile stress, the improvement wherein the wall of said outer pipe end is of roundish cross-section except for at least one sector of increased radius defining an inwardly opening, axially extending channel, the wall of said inner pipe end is of roundish crosssection except for at least one wall-extension sector of increased radius defining a spline portion, said inner pipe end extending into said outer pipe end with said spline portion in said channel in loose fitting engagement with the pipe ends in an unstressed condition, the peripheral length on the inner surface of a cross-section of said channel being less than the peripheral length on the outer surface of a cross-section of said spline portion, said force applying means comprising fastener means having a shank extending through said channel with a movable element on at least one end reacting on said channel whereby tightening of the fastener means draws the wall of the channel toward the spline portion and the outer pipe end is stretched over the inner pipe end.

2. The invention as defined in claim 1 wherein said spline includes concave surfaces disposed face to face, respectively, with the opposed walls of said channel, and wherein said fastener means extends through the opposed walls of said channel and through said spline,

3. The invention as defined in claim 1 wherein said fastener means comprises a bolt extending through said spline and said chaNnel, a shaped spacer member on said bolt, and a nut on said bolt for forcing said spacer member into the wall of said channel against the reaction of said spline whereby the wall of said channel is drawn into engagement with the spline.

4. The invention as defined in claim 1 wherein said spline has a concave outer surface and wherein said fastening means comprises a bolt extending radially through said spline and the outer wall of said channel, a shaped spacer member on the bolt outside said channel and a nut on the bolt outside said spacer member.

5. The invention as defined in claim 1 wherein said spline is formed integrally with the wall of said inner pipe.

6. The invention as defined in claim 5 wherein a reaction member is disposed interiorly of the walls of said spline.

7. The invention as defined in claim 1 including a second inner pipe extending into the other end portion of the outer pipe and being of roundish cross-section except for at least one wall extension sector of increased radius defining a second spline portion, said second inner pipe end extending into said other outer pipe end with said spline portion in said channel in loose fitting engagement with the other outer pipe end and the second inner pipe end in an unstressed condition, the peripheral length on the inner surface of a cross-section of said channel being less than the peripheral length on the outer surface of a cross-section of said second spline portion, said force applying means comprising fastener means engaging said channel opposite both of the aforementioned spline portions and, when tightened, deforming the wall of the channel into surface engagement with both of the aforesaid spline portions whereby the outer pipe end is stretched over both of the aforementioned inner pipe ends.

8. The invention as defined in claim 7 wherein said spline portions comprise an elongated reaction block of one piece construction separated from the part of said inner pipe which is of roundish cross-section.

9. The invention as defined in claim 8 wherein said fastener means includes at least one bolt extending through said channel and said spline and including a nut on said bolt.

10. The invention as defined in claim 9 wherein said elongated reaction block includes concave surfaces disposed fact to face, respectively, with the opposed walls of said channel, and wherein said bolt extends through the opposed walls of said channel and through said spline.

11. The invention as defined in claim 10 wherein said concave surfaces have a curvature which in cross-section thereof extends tangentially of the curvature of said inner pipe at the point of intersection of said curvature and the surface of said pipe.

12. The invention as defined in claim 11 wherein said curvature of said concave surface is approximately circular.

13. The invention as defined in claim 10 wherein said outer pipe is an axially split sleeve, said axially elongated reaction block defining an axially extending slot in the outer surface thereof, the free ends of said split sleeve being oppositely disposed at the outer wall of said channel, said ends being extended radially inwardly into said slot.

14. The invention as defined in claim 13 wherein said bolt extends through the sidewalls of said channel and through the free ends of said sleeve lying in said slot.