Patent US2300334A successfully refreshed from Google Patents.
Patent US4110144A successfully refreshed from Google Patents.
US4110144A
Expired / Lapsed
US
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Mechanically locked bell and spigot coupling for ducts and method of forming
Assignee: General Electric Canada Co
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Filing: 1977-03-28
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Granted: 1978-08-29
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Expires: 1997-03-28
Abstract
Abstract A bell and spigot coupling is provided with an abrasive-material insert to increase the disengagement force necessary to uncouple the ducting.
Inventors
- 👤 Amsey Buehler
- 👤 Kirk T. Butcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:52
CPC Classifications
F; F16; F16L; F16L37/00; F16L37/02; F16L21/00; F16L21/08; Y; Y10; Y10S; Y10S285/00; Y10S285/919; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
125 words
The method of manufacturing a plastic duct having a bell coupling formation integral therewith comprising the steps of: (a) providing a mandrel having a duct forming section; a bell forming section; and a neck section interconnecting said duct and bell forming sections; (b) locating an elastomeric sealing means around said neck section; (c) providing abrasive means around at least a portion of said bell forming section; (d) winding glass fiber roving coated with uncured epoxy resin around said mandrel sections to form a predetermined wall thickness; (e) curing the epoxy resin, (f) removing the duct and bell coupling formation with the integral elastomer sealing means and abrasive means, and (g) forming at least one axially aligned slot in the wall of the bell coupling formation.
Claim 2
Independent Claim
125 words
The method of manufacturing a plastic duct having a bell coupling formation integral therewith comprising the steps of: (a) providing a mandrel having a duct forming section; a bell forming section; and a neck section interconnecting said duct and bell forming sections; (b) locating an elastomeric sealing means around said neck section; (c) providing abrasive means around at least a portion of said bell forming section; (d) winding glass fiber roving coated with uncured epoxy resin around said mandrel sections to form a predetermined wall thickness; (e) curing the epoxy resin, (f) removing the duct and bell coupling formation with the integral elastomer sealing means and abrasive means, and (g) forming at least one axially aligned slot in the wall of the bell coupling formation.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein said elastomeric sealing means is constructed from a polyurethane.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein said abrasive means comprises a sleeve the inner wall of which is coated with abrasive grit.
Claim 5
Dependent Claim
14 words
The method of claim 3 wherein the elastomeric sealing means is constructed from polyurethane.
Claim 6
Dependent Claim
11 words
The method of claim 1 wherein said neck section is frusto-conical.
Claim 7
Dependent Claim
14 words
The method of claim 5 wherein the elastomeric sealing means is constructed from polyurethane.
References Cited (Backward Citations)
US2420778A
Cited
US2702716A
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US3252192A
Cited
US3623930A
Cited
US3661670A
Cited
US3775207A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |