What the patents claim
Claim 1 of US 9,989,186 recites a body with a bore, an aperture forming a breech, a ramrod compartment, a chamber that receives the pig, a neck that connects to a pipe, and a breech shield that covers the breech. Advancing the ramrod forces the pig through the neck and into the pipe.
Claim 1 of US 11,644,145 is similar but puts a breech plate on the end of the ramrod in place of the shield.
What we found
US 5,208,937 (priority December 1990) is a pig launcher with a chamber that holds the pig and fastens to the pipeline end. A cover carrying a threaded or hydraulic rod is attached, and the rod pushes the pig through the chamber into the pipeline.
US 5,186,757 (1991) is a portable launcher with a barrel, a sealing door and a nozzle that engages the pipe; the pig is driven out by pressure. US 6,769,152 (2002) is an upright loading chamber with a removable cover.
The ’186 patent has two citations of its own and five across its family. None of these references is among them.
Why it matters to the defendant
The examiner saw very little pigging art, and the 1990 launcher has the core mechanism: a portable loader on the pipe end, with a rod that advances the pig through a chamber into the pipe, 25 years before the priority date. The claim’s breech aperture, ramrod compartment and breech shield are not clearly shown, so the case turns on whether a second launcher reference, such as the 1991 door-and-nozzle design, supplies them.
The answer in Patent Mechanics
The search as it appears in the app, abridged.
| Reference | Assignee | Priority | Citation record | Fit |
|---|---|---|---|---|
| US 5,208,937 | Unassigned | 1990 | Not cited | Strong |
| US 5,186,757 | Unassigned | 1991 | Not cited | Partial |
| US 6,769,152 | Parnell Consultants | 2002 | Not cited | Partial |
| Element | Claim language (abridged) | ’937 | ’757 |
|---|---|---|---|
| 1[a] | Body with a bore along its axis | ✓ | ✓ |
| 1[b-c] | Breech aperture; ramrod compartment | ? | ? |
| 1[d-e] | Chamber receives the pig; neck connects to the pipe | ✓ | ✓ |
| 1[f] | Breech shield selectively covers the breech | – | ? |
| 1[g] | Ramrod forces the pig through the neck into the pipe | ✓ | – |
References
| Reference | Title | Priority | Covers | Gaps |
|---|---|---|---|---|
| US 5,208,937 | Apparatus for launching pigs into pipelines | 1990-12-27 | Chamber on the pipe end; rod through a cover pushes the pig into the pipeline | No breech aperture with a shield; no separate ramrod compartment |
| US 5,186,757 | Pig loading system and method | 1991-08-26 | Portable launcher with a sealing door, reducer and nozzle into the pipe | Pressure-driven, no ramrod |
| US 6,769,152 | Launcher for passing a pig into a pipeline | 2002-06-19 | Loading chamber with a removable cover | Gravity-fed, no ramrod |
Limits of this analysis
- First-pass reading of claims and abstracts; the breech elements need a full-text comparison with US 5,208,937.
- Pigging tools are sold as products and described in industry catalogues, which are outside this patent search.
“Not cited” means the reference does not appear in the examiner or applicant citations of the patent or its family in our index. This article is research, not legal advice, and makes no finding that any claim is invalid.
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