# US 4,396,213 A · Method of joining pipe ends and joint formed thereby

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- Number: US 4,396,213 A
- Document ID: US4396213A
- Status: Granted
- Kind: A
- Application number: 06/298,749
- Filed: 1981-09-02
- Granted: 1983-08-02
- Earliest claimed: 1981-09-02
- Assignees: John J. Kirlin; Wayne T. Day
- Inventors: Hugh M. Hawkins
- Web page: https://patentgrep.com/patent/US4396213A

## CPC

- F16L 13/161: {the pipe or collar being deformed by crimping or rolling}
- F16L 13/08: Soldered joints
- F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL

## Abstract

A soldered pipe joint and a method for making same, wherein the flow of solder from one end of the overlapped pipe ends is terminated at a set of axially aligned circumferential grooves formed in the two pipe ends.

## Claims

### Claim 1

A joint for joining together overlapping pipe ends comprising:
a first circumferential groove formed into the exterior of the inner pipe end,
a second circumferential groove formed into the exterior of the outer pipe end, said outer pipe including a circumferential protrusion across from the second groove and formed as a result of the formation of said second groove,
a first and second grooves and the said circumferential protrusion all being axially aligned with the protrusion extending at least partially into the first groove to tightly engage the first groove to form a circumferentially continuous solder stop,
the shape of the protursion being dissimilar from the shape of the first circumferential groove,
and including a solder composition in the space between the overlapped pipe ends from an exposed end of the overlap, up to the grooves, and substantially terminating at the said stop with no more than an insignificant amount of solder located beyond the grooves.

### Claim 2 (depends on 1)

A joint according to claim 1, wherein the grooves are circular.

### Claim 3 (depends on 1)

A joint according to claim 1, wherein each groove is formed into the exterior of its respective pipe, forcing some material thereof radially inwardly.

### Claim 4 (depends on 1)

A joint according to claim 1, wherein the pipe material is metal and the solder is a silver composition.

### Claim 5 (depends on 4)

A joint according to claim 4, wherein the pipe is copper.

### Claim 6

A method for forming a pipe joint between two concentric overlapping pipe ends, comprising the steps of:
forming a circumferential groove into the exterior of the smaller, interior pipe,
inserting the smaller pipe into an open end of the larger pipe to a predetermined position,
forming a circumferential groove into the exterior of the outer, larger pipe end so that the groove is aligned with the groove on the smaller, inner pipe, the confronting surfaces of the grooves tightly engaging one another to form a circumferentially continuous solder stop,
heating the pipe ends, and while the pipe ends are thus heated,
introducing a solder material into an exposed end of the overlapped pipe ends, such that the solder flows between the pipe ends to solder them together, and is substantially terminated, in the axial direction, at the said stop, such that no more than an insignificant amount of solder passes beyond the grooves.

### Claim 7 (depends on 6)

The method according to claim 6, wherein the grooves are circular.

### Claim 8 (depends on 7)

The method according to claim 7, wherein the grooves are formed in the exterior of each pipe end, forcing some material of each pipe end radially inwardly.

### Claim 9 (depends on 6, 7, 8)

The method according to any one of claims 6, 7 or 8 wherein the pipes are metallic and the solder is a silver composition.

### Claim 10 (depends on 9)

The method according to claim 9, including heating the pipes to a temperature of approximately 1100.degree. F.

### Claim 11 (depends on 6, 7, 8)

The method according to any one of claims 6, 7 or 8 wherein the step of forming the grooves includes using a pipe cutting tool having at least one grooving roller and a support roller.

### Claim 12 (depends on 6, 7, 8)

The method according to any one of claims 6, 7 or 8 wherein each groove has a width in the axial direction of approximately 1/16".