US3771546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circular knife cutter for fitting used with plastic main or pipes
Assignee: Mueller Co
•
Filing: 1972-10-11
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Granted: 1973-11-13
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Expires: 1992-10-11
Abstract
Abstract A tapping plug for use with a plastic tapping T secured to a plastic main, the tapping T being of the type having a throughbore with an interior thread and a lateral outlet communicating with the bore, and adapted to be connected to a service pipe. The tapping plug which includes a plastic plug body member having an exterior thread for engaging the interior thread of the throughbore so that the same can be advanced therethrough. The plug body has a thin wall cylindrical metal band cutter member, coaxially fixed to one end thereof. The cutter member has a knife edge defined by an internal bevelled surface and an external bevelled surface, thus providing controlled deformation of the same during cutting and resulting in a reduced cutting load between the plastic main and the plastic body member through the plastic tapping T.
Inventors
- 👤 R Roos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:40
CPC Classifications
F; F16; F16L; F16L47/00; F16L47/26; F16L47/34; Y; Y10; Y10T; Y10T137/00; Y10T137/598; Y10T137/612; Y10T137/6123
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
133 words
A tapping plug for use with a plastic tapping T secured to a plastic main, the tapping T having a through bore with an interior thread and a lateral outlet communicating with the bore and adapted to be connected to a service pipe, the improvement comprising: a plastic plug body having an exterior thread for engaging the interior thread of the through-bore so that the same can be advanced therethrough; and a thin wall cylindrical metal band cutter member of smaller diameter than and coaxially fixed to, one end of said plastic plug body, said metal band cutter member having a knife edge defined by an external bevelled surface and an internal bevelled surface, said external bevelled surface and said internal bevelled surface having an included angle therebetween in the order of 20*.
Claim 2
Dependent Claim
133 words
A tapping plug for use with a plastic tapping T secured to a plastic main, the tapping T having a through bore with an interior thread and a lateral outlet communicating with the bore and adapted to be connected to a service pipe, the improvement comprising: a plastic plug body having an exterior thread for engaging the interior thread of the through-bore so that the same can be advanced therethrough; and a thin wall cylindrical metal band cutter member of smaller diameter than and coaxially fixed to, one end of said plastic plug body, said metal band cutter member having a knife edge defined by an external bevelled surface and an internal bevelled surface, said external bevelled surface and said internal bevelled surface having an included angle therebetween in the order of 20*.
Claim 3
Dependent Claim
73 words
A tapping plug as claimed in claim 1 in which said external bevelled surface of said cutter member has an angle with respect to an axis extending through said knife edge and parallel to an axis of the cutter member in the order of 10* and wherein said internal bevelled surface of said cutter member has an angle with respect to said axis through said knife edge also in the order of 10*.
Claim 4
Dependent Claim
50 words
A tapping plug as claimed in claim 1, in which said external bevelled surface and said internal bevelled surface of said cutter member each has an angle with respect to an axis extending through said knife edge and parallel to an axis of the cutter member of at least 5*.
Claim 5
Dependent Claim
61 words
A tapping plug as claimed in claim 3, in which one of said external bevelled surface and said internal bevelled surface of said cutter member has an angle to said axis extending through said knife edge in the order of 15* and the other of said external bevelled surface and internal bevelled surface has an angle in the order of 5*.
Claim 6
Dependent Claim
46 words
A tapping plug as claimed in claim 1, in which said cylindrical metal band cutter member is provided with a thread on its interior surface extending from adjacent the internal bevelled surface, said last mentioned thread receiving and retaining a coupon cut from the plastic main.
Claim 7
Dependent Claim
26 words
A tapping plug as claimed in claim 5, in which the thread on the interior surface of said cutter member is substantially rectangular in radial section.
Claim 8
Dependent Claim
51 words
A tapping plug as claimed in claim 1, in which said cylindrical metal band cutter member is provided with a counter bore on its interior surface which defines an inner undercut lip structure adjacent the inner bevelled edge, said lip structure receiving and retaining a coupon cut from the plastic main.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |