COUPLING FOR PLASTIC PIPE

• US 3,695,638 A
• Filed: 03/18/1970
• Issued: 10/03/1972
• Est. Priority Date: 03/18/1970
• Status: Expired due to Term

• Current Assignee: James Blakeley
• Original Assignee: James Blakeley
• Inventors: Blakeley, James
• Primary Examiner(s): Arola, Dave W.
• Application Number:
  US05/020,531
• Time in Patent Office: 930 Days
• Field of Search: 285/111,373,423,112,419,223,366,367,407,410
• US Class Current: 285/112
• CPC Class Codes: F16L 17/04 with longitudinally split or divided sleeve

Abstract

A mechanical clamp type coupling and joint for joining together the ends of sections of plastic pipe incorporates elements to maintain an effective joint regardless of stress concentration and the effects of flexural or bending forces on the joint. The pipe sections are grooved circumferentially at a position adjacent their ends to receive the key sections of cylindrical segmented coupling housings. A pressure responsive gasket mounted within the housing has lips engaging the exterior of the pipe sections between their grooves and opposed ends. Shoulders forming circumferential sections extend laterally outwardly from the sides of the coupling housings to overlie the pipe outwardly of the grooves. The interior surfaces of these shoulders and the exterior surface of the pipe are concentric and the clearance between them is restricted preferably to a definite tolerance to protect the joint from opening up under flexing or bending forces.

Claims

1. In coupling constructions for grooved end pipes, A coupling housing element formed of rigid material and forming a segment of a cylinder, said housing element comprising a base portion, side portions at both sides of said base portion extending radially inwardly to form a gasket receiving channel between said side portions and said base portion, each of said side portions being integrally formed with radially inwardly extending portions providing key sections in the form of ribs having straight sides extending throughout substantially the circumferential length of said segment and a radially extending surface facing axially inwardly of the housing element, and said side portions being formed with laterally outwardly extending wing portions extending outwardly with respect to said key sections a distance substantially greater than the width of said key sections so as to overlie said pipe surface beyond the groove therein a greater distance than the width of said key sections, said wing portions having a curvature concentric with the curvature of said housing element, said wing portions extending a shorter circumferential distance than the circumferential extent of said housing element and the inner surfaces of said wing portions being of an interior diameter greater than the interior diameter of said radially extending surface of said inwardly extending portions but only slightly greater than the outer diameter of the pipe to be joined by a coupling formed of a plurality of said housing elements, and means formed on said housing element for joining the same to an adjacent housing element.

2. In coupling construction as in claim 1, said housing element being formed with exterior reinforcing ribs, said exterior reinforcing ribs extending across said housing element and engaging said wing portions to reinforce the same against flexing.

3. A pipe joint made up of sections of grooved end pipe and a coupling housing surrounding the same including, said pipe sections, adjacent said joint being formed with exterior circumferential grooves spaced outwardly from the ends thereof, said coupling housing being formed of a plurality of segmental sections of a cylinder assembled together in cylindrical form on to the pipe ends being joined, each of said segments including a base portion, radially inwardly extending side portions extending inwardly from said base portion and forming a gasket recess therewithin, key sections extending radially inwardly from said side portions, extending into the grooves of said pipe but of less width and of greater inner diameter than the diameter of the bottom of said groove, and said side portions being formed with concentric laterally outwardly extending wing portions, said wing portions overlying the surface of said pipes outwardly of said coupling grooves, the inner diameter of said wing portions being only slightly greater than the outer diameter of said pipe whereby movement of either of said pipe out of its normal axial alignment is checked by the engagement of said inner wing surface with said pipe surface and a gasket in said gasket recess having portions overlying said pipe ends and engaging the portions of said pipe inwardly of said grooves.

4. A joint as in claim 3, said coupling housing being formed of relatively strong rigid material and said pipe sections being formed of somewhat yieldable plastic material.

5. A joint as in claim 4, said wing portions overlying said pipe at spaced positions about the circumference of said pipe.

6. A joint as in claim 4, the clearance between the interior surface of said wings and the exterior surface of said pipe lying between 0.010 and 0.014.

7. A joint as in claim 4 and including reinforcing ribs extending transversely of said segments across the outer surface of the same, said ribs engaging the exterior of said wing portions to prevent radial outwardly flexing of the same.

8. A pipe joint made up of sections of grooved end pipe and a coupling surrounding the same including, said pipe sections, adjacent said joint being formed with exterior circumferential grooves spaced outwardly from the ends thereof, said coupling housing being formed of a plurality of segmental sections of a cylinder secured together in cylindrical form on the pipe ends being joined, each of said segments including a base portion, radially inwardly extending side portions extending inwardly from said base portion and forming a gasket recess therewithin, a gasket within said gasket recess, key sections extending radially inwardly from said side portions, extending into the grooves of said pipe but of less width and of greater inner diameter than the diameter of the bottom of said groove, and said side portions being formed with concentric laterally outwardly extending wing portions, said wing portions overlying the surface of said pipes outwardly of said coupling grooves, the inner diameter of said wing portions in an unassembled, unstressed, state being only slightly greater than the outer diameter of said pipe, and ring means for encircling the exterior of said wing portions to stress said wing portions and force said wing portions tightly against the outer surface of said pipe throughout the overlying extent thereof, to prevent movement of either of said pipes out of its normal axial alignment.

9. The joint of claim 8, said wing portions overlying said pipe at spaced positions about the circumference of said pipe.