# US 4,397,484 A · Locking coupling system

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- Number: US 4,397,484 A
- Document ID: US4397484A
- Status: Granted
- Kind: A
- Application number: 06/369,329
- Filed: 1982-04-16
- Granted: 1983-08-09
- Earliest claimed: 1982-04-16
- Assignees: Mobil Oil Corporation
- Inventors: Henry W. Miller
- Web page: https://patentgrep.com/patent/US4397484A

## CPC

- F16L 15/006: {with straight threads}
- E21B 17/042: Threaded
- E21B 17/043: with locking means
- Y10S 285/913: Interdigitating
- Y10T 29/49963: Threaded fastener
- F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An apparatus is disclosed wherein oppositely threaded, dissimilar coarseners threads are provided to receive couplings having tapered splined ends.

## Claims

### Claim 1

A system for joining two pipe ends comprising:
a first pipe having an internally and externally threaded end, said external threads having a predetermined pitch;
a second pipe having an externally threaded end with two sets of external threads, one set of said external threads for matching said internal threads of said first pipe and an other set of external threads spaced behind one set of threads having a different pitch from said predetermined pitch of said external threads of said first pipe and threaded in a direction opposite from said one set of external threads; and
coupling means having two sections, one section having threads matching said external threads on said first pipe and an other section having threads matching said other set of threads on said second pipe for locking said first and said second pipe together.

### Claim 2 (depends on 1)

The system according to claim 1 wherein said end of said second pipe has a smaller diameter for said first set of external threads than for said second set of external threads.

### Claim 3 (depends on 2)

The system according to claim 2 wherein said coupling halves have spleened ends for interlocking said one section with said other section.

### Claim 4

A method for joining two pipe ends, a first pipe end having its outermost section with external threads which screws into an internally threaded second pipe end comprising:
providing threads on said first pipe end and said second pipe end wherein said threads run in the same direction and having different pitches;
providing coupling halves with matching threads for each of said first pipe end and said second pipe end;
screwing said coupling halves in opposite directions to approach one another; and
rotating said coupling halves in the same direction when said coupling halves touch.

### Claim 5 (depends on 4)

The method according to claim 4 also including the steps of:
providing spleened ends on said coupling halves;
rotating said coupling halves until said spleened ends are in line; and
rotating said coupling halves in the same direction until said spleen halves interlock with one another.