Patent US3725968A successfully refreshed from Google Patents.
US3725968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double-dished pipeline pig
Assignee: Individual
•
Filing: 1971-05-27
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Granted: 1973-04-10
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Expires: 1991-05-27
Abstract
Abstract A pipeline pig having a dished face at each end, the dished face improving the wiping action of the periphery of the pig as it passes through the pipeline, there being a slightly compressible axial member cast internally of the pig extending from the dished face at one end to the dished face at the other end to protect the pig against pressure surges which tend to rupture the pig in transit in the pipeline. The invention also relates to a method of forming for such pigs.
Inventors
- 👤 K Knapp
- 👤 M Knapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:07
CPC Classifications
B; B08; B08B; B08B9/00; B08B9/02; B08B9/027; B08B9/04; B08B9/053; B08B9/055; B08B9/0553; B29; B29C; B29C44/00; B29C44/02; B29C44/12; B29C44/1266; B29C33/00; B29C33/12; B29C33/14; B29L; B29L2031/00; B29L2031/74; B29L2031/7406
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
119 words
A pipeline pig which comprises an elongate cylindrical body having an elongate dimension from end to end and having a cavity therewithin and adapted to fit within a pipeline and being of approximately equal diameter to the inside diameter of the pipeline; concave surfaces of a desired thickness at the opposite ends of said pig, said surfaces being formed of a resilient material different from the material of said body and permitting some flexure thereof to enhance the gripping action of the pig as it engages the side wall of the pipe; an elongate support member extending through the central portions of said pig for connecting said surfaces; and, said cylindrical body being formed substantially of a resilient material.
Claim 2
Dependent Claim
119 words
A pipeline pig which comprises an elongate cylindrical body having an elongate dimension from end to end and having a cavity therewithin and adapted to fit within a pipeline and being of approximately equal diameter to the inside diameter of the pipeline; concave surfaces of a desired thickness at the opposite ends of said pig, said surfaces being formed of a resilient material different from the material of said body and permitting some flexure thereof to enhance the gripping action of the pig as it engages the side wall of the pipe; an elongate support member extending through the central portions of said pig for connecting said surfaces; and, said cylindrical body being formed substantially of a resilient material.
Claim 3
Dependent Claim
34 words
The invention of claim 1 including a cylindrical core of lower density material than that of said body within the cavity of said cylindrical body of said pig and surrounding said elongate support member.
Claim 4
Dependent Claim
42 words
The invention of claim 1 including a cylindrical core of low-density polyolefin foam in said cavity in said body and a surrounding polyolefin body cast to said core and having an outer surface hardness in the range of 70 durometer or greater.
Claim 5
Dependent Claim
24 words
The invention of claim 1 including on said body a plurality of ring-like members extending to the periphery of the inside of the pipeline.
Claim 6
Dependent Claim
21 words
The invention of claim 2 further including passage means communicating the interior of the pipeline with the cavity within said body.
Claim 7
Dependent Claim
30 words
The invention of claim 2 further including an external coating on said cylindrical body which includes therein particles of a material harder than the resilient material comprising said cylindrical body.
Claim 8
Dependent Claim
19 words
The invention of claim 6 wherein said particles are tungsten carbide particles which are embedded in said resilient material.
Claim 9
Dependent Claim
31 words
The invention of claim 6 wherein said resilient material is a urethane material which is molded about said particles which extend radially inwardly from the outer face thereof a predetermined depth.
Claim 10
Dependent Claim
38 words
The invention of claim 1 wherein said cylindrical body includes spiralled grooves extending at least part-way along the length of the body thereof sufficient to impart a slight rotative twist to said pig as it traverses the pipeline.
Claim 11
Dependent Claim
22 words
The invention of claim 9 wherein said spiral grooves are found at at least two locations along the length of said body.
References Cited (Backward Citations)
US1415600A
Cited
US1547440A
Cited
US1713895A
Cited
US3403701A
Cited
US3543323A
Cited
US3602934A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |