Joint for variable wall thickness conduit

• US 5,547,230 A
• Filed: 04/28/1995
• Issued: 08/20/1996
• Est. Priority Date: 04/28/1995
• Status: Expired due to Fees

• Current Assignee: Lamson & Sessions Company (ABB Limited)
• Original Assignee: Lamson & Sessions Company (ABB Limited)
• Inventors: Hawkins, Thomas W., Bank, Michael D.
• Primary Examiner(s): Arola, Dave W.
• Application Number:
  US08/430,434
• Time in Patent Office: 480 Days
• Field of Search: 285/330, 285/351, 285/423, 285/345, 285/110
• US Class Current: 285/110
• CPC Class Codes: F16L 21/035 placed around the spigot end before connection F16L21/022, F16L21/025 take precedence
• CPC Class Codes: F16L 25/10 Sleeveless joints between two pipes, one being introduced into the other
• CPC Class Codes: F16L 47/18 Adjustable joints; Joints allowing movement

Abstract

A force-transmitting joint formed between two pipe sections is provided that is particularly suited for an extruded, plastic pipe having a variable wall thickness. The joint has a smooth outer surface and a constant gap in which a sealing member is retained. The pipe section has an outer wall including an outer surface and an inner surface with a variable wall thickness defined therebetween. A first end of the pipe section includes a first joint member comprising a first support surface having a constant width. The first joint member further comprises an outwardly extending sealing leg having a variable width. A second end of the pipe includes a second joint member comprising a second support surface having a constant width which is less than the width of the first support surface. The second joint member further comprises a recess having a variable thickness. An annular sealing member is assembled onto the sealing leg. When the first joint member of one pipe section is joined to the second joint member of another pipe section, the first support wall and second support wall align in a force-transmitting relationship, the sealing leg is at least partially received in the recess and a constant-width gap is formed between a wall of the recess and the sealing leg. The sealing member is retained in the constant-width gap.

Claims

1. A conduit section having an outer wall, a first end and a second end, said wall having an inner surface and an outer surface, a variable thickness being defined therebetween, said conduit section comprising:

a. first joint member formed at said first end, said first joint member comprising;

i. a first support surface formed adjacent said outer surface, said first support surface having a constant width; and

ii. a sealing leg formed adjacent said inner surface; and

b. a second joint member formed at said second end, said second joint member comprising;

i. a second support surface formed adjacent said outer surface, said second support surface having a constant width that is less than the width of said first support surface; and

ii. a recess formed adjacent said inner surface;

whereby said first joint member aligns and joins to the second joint member of a second conduit section and said second joint member aligns and joins with the first joint member of a third conduit section.

2. A conduit section as defined in claim 1 which is comprised of plastic.

3. A conduit section as defined in claim 2 wherein said plastic is PVC.

4. A conduit section as defined in claim 1 wherein said first support surface and said second support surface are planar.

5. A conduit section as defined in claim 1 wherein said wall has a nominal thickness and said first support surface is at least 75% as wide as the nominal thickness of said wall.

6. A conduit section as defined in claim 1 wherein said conduit has a longitudinal axis and said first support surface and said second support surface are each formed perpendicular to said longitudinal axis.

7. A conduit section as defined in claim 1 wherein said conduit has a longitudinal axis and said recess has a length as measured along said longitudinal axis, and said sealing leg has a length as measured along said longitudinal axis, said length of said leg being less than the length of said recess.

8. A joint formed between two sections of conduit, said joint comprising:

a. a first joint member comprising;

i. a first wall having a first outer surface and a first inner surface, a variable thickness being defined therebetween;

ii. a first support surface formed adjacent said first outer surface, said first support surface having a constant width;

iii. a sealing leg formed adjacent said first inner surface; and

b. a second joint member joined to said first joint member, said second joint member comprising;

i. a second wall having a second outer surface and a second inner surface, a variable thickness being defined therebetween;

ii. a second support surface being formed adjacent said second outer surface, said second support surface having a constant width that is less than the width of said first support surface, said second support surface being in force-transmitting relationship with said first support surface;

iii. a recess formed adjacent said second inner wall, said recess having a sealing wall, a constant-width gap being formed between said sealing wall and said sealing leg; and

c. a sealing member retained within said constant-width gap, said sealing member contacting said sealing wall and said sealing leg.

9. A conduit section having an outer wall, a first end and a second end, said wall having an inner surface and an outer surface, a variable thickness being defined therebetween, said conduit section comprising:

a first joint member formed at said first end, said first joint member comprising;

i. a first support surface formed adjacent said inner surface, said first support surface having a constant width; and

ii. a sealing leg formed adjacent said outer surface; and

b. a second joint member formed at said second end, said second joint member comprising;

i. a second support surface formed adjacent said inner surface, said second support surface having a constant width that is less than the width of said first support surface; and

ii. a recess formed adjacent said outer surface;

whereby said first joint member aligns and joins to the second joint member of a second conduit section and said second joint member aligns and joins with the first joint member of a third conduit section.