US4256920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Re-enterable duct seal
Assignee: Nortel Networks Ltd
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Filing: 1979-04-18
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Granted: 1981-03-17
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Expires: 1999-04-18
Abstract
Abstract A re-entrable duct is provided through which a cable is adapted to penetrate a wall, e.g., of an environmentally controlled manhole. The re-entrable duct includes a duct pipe, e.g., a length of steel pipe, through which the cable passes. A resilient annular plug having a central aperture through which the cable passes, e.g., a so-called split rubber duct plug, is situated at each end of the duct pipe. The annular plugs with the duct pipe define a sealant chamber. A quantity of bentonite is provided which substantially fills the sealant chamber. A sleeve is secured to one end of the duct pipe adjacent one such split rubber duct plug, that sleeve including an end plate having a central aperture therethrough which the cable passes. The cable is thus secured within the central aperture in a circumferential, hermetic sealed manner, thereby defining a secondary sealed air chamber between the split rubber duct plug and the end plate. Finally, a crimpable tube is disposed within, and projects from the central aperture in the end plate, and is crimped into hermetically sealed contact onto the cable. Together, the three components of the re-entrable duct seal provide a three-stage seal against moisture and at least a one-stage seal against gas. All components can be re-entered if necessary, and all may be placed from one end of the steel duct pipe only.
Inventors
- 👤 Rand K. Ayres
- 👤 Hassan A. Sherif
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:23
CPC Classifications
H; H01; H01B; H01B17/00; H01B17/26; H01B17/30; H02; H02G; H02G9/00; H02G9/10
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
244 words
A re-entrable duct through which a cable is adapted to penetrate a wall, said wall having an aperture therethrough, said duct comprising: (a) a duct pipe through which said cable is adapted to pass, said duct pipe being adapted to be secured within said aperture in said wall; (b) a resilient split rubber duct plug disposed at each end of said duct pipe, said cable being adapted to pass through a central aperture in each of said split rubber duct plugs, each of said split rubber plugs being provided with manually operable means to act on said central aperture, whereby each said central aperture is adapted hermetrically sealingly and circumferentially to engage said cable, said annular plugs and said duct pipe defining a primary sealant chamber therebetween; (c) a quantity of bentonite substantially filling said primary sealant chamber and adapted to surround said cable; (d) a sleeve secured to one end of said duct pipe adjacent one said split rubber duct plug, said sleeve including an end plate having a central aperture therethrough through which said cable is adapted to pass, said cable being adapted to be secured within said central aperture in a circumferential hermetic sealed manner, thereby defining a secondary sealed air chamber between said split rubber duct plug and said end plate; and (e) a crimpable tube disposed within, and projecting from, said central aperture in said end plate, and adapted to be crimped into hermetically sealed contact onto said cable.
Claim 2
Dependent Claim
244 words
A re-entrable duct through which a cable is adapted to penetrate a wall, said wall having an aperture therethrough, said duct comprising: (a) a duct pipe through which said cable is adapted to pass, said duct pipe being adapted to be secured within said aperture in said wall; (b) a resilient split rubber duct plug disposed at each end of said duct pipe, said cable being adapted to pass through a central aperture in each of said split rubber duct plugs, each of said split rubber plugs being provided with manually operable means to act on said central aperture, whereby each said central aperture is adapted hermetrically sealingly and circumferentially to engage said cable, said annular plugs and said duct pipe defining a primary sealant chamber therebetween; (c) a quantity of bentonite substantially filling said primary sealant chamber and adapted to surround said cable; (d) a sleeve secured to one end of said duct pipe adjacent one said split rubber duct plug, said sleeve including an end plate having a central aperture therethrough through which said cable is adapted to pass, said cable being adapted to be secured within said central aperture in a circumferential hermetic sealed manner, thereby defining a secondary sealed air chamber between said split rubber duct plug and said end plate; and (e) a crimpable tube disposed within, and projecting from, said central aperture in said end plate, and adapted to be crimped into hermetically sealed contact onto said cable.
Claim 3
Dependent Claim
21 words
The re-entrable duct of claim 1 wherein said rubber out of which said split rubber duct plug is formed is neoprene.
Claim 4
Dependent Claim
16 words
The re-entrable duct of claim 1 wherein said bentonite is in the form of compressed pellets.
Claim 5
Dependent Claim
16 words
The re-entrable duct of claim 1 wherein said bentonite is tamped into said primary sealant chamber.
Claim 6
Dependent Claim
17 words
The re-entrable duct of claim 1 wherein said bentonite is packed in a plurality of rupturable bags.
Claim 7
Dependent Claim
14 words
The re-entrable duct of claim 5 wherein said rupturable bags are made of paper.
Claim 8
Dependent Claim
21 words
The re-entrable duct of claim 1 wherein said sleeve, said end plate and said crimpable tube are each formed of lead.
Claim 9
Dependent Claim
29 words
The re-entrable duct of claim 1 wherein a sealing compound is disposed around said crimpable tube between said crimpable tube and said cable prior to crimping said crimpable tube.
Claim 10
Dependent Claim
23 words
The re-entrable duct of claim 1 wherein said sleeve is secured to the said one end of said duct pipe by threaded engagement.
Claim 11
Dependent Claim
16 words
The re-entrable duct of claim 1 wherein said duct pipe is a length of steel tubing.
Claim 12
Dependent Claim
203 words
In combination, a re-entrable duct, a wall having an aperture therethrough, and a cable secured within said duct, comprising: (a) a duct pipe through which said cable passes, said duct pipe being secured to said aperture in said wall; (b) a resilient split rubber duct plug disposed at each end of said duct pipe, said cable passing through a central aperture in each of said split rubber duct plugs and being secured within each said aperture in a hermetically sealed and circumferential engagement, said annular plugs and said duct pipe defining a primary sealant chamber therebetween; (c) a quantity of bentonite substantially filling said primary sealant chamber and surrounding said cable; (d) a sleeve secured to one end of said duct pipe adjacent one said split rubber duct plug, said sleeve including an end plate having a central aperture therethrough through which said cable passes, said cable being secured within said central aperture in a circumferential hermetic sealed manner, thereby defining a secondary sealed air chamber between said split rubber duct plug and said end plate; and (e) a tube disposed within and projecting from said central aperture in said end plate, said tube being crimped in hermetically sealed engagement onto said cable.
Claim 13
Dependent Claim
203 words
In combination, a re-entrable duct, a wall having an aperture therethrough, and a cable secured within said duct, comprising: (a) a duct pipe through which said cable passes, said duct pipe being secured to said aperture in said wall; (b) a resilient split rubber duct plug disposed at each end of said duct pipe, said cable passing through a central aperture in each of said split rubber duct plugs and being secured within each said aperture in a hermetically sealed and circumferential engagement, said annular plugs and said duct pipe defining a primary sealant chamber therebetween; (c) a quantity of bentonite substantially filling said primary sealant chamber and surrounding said cable; (d) a sleeve secured to one end of said duct pipe adjacent one said split rubber duct plug, said sleeve including an end plate having a central aperture therethrough through which said cable passes, said cable being secured within said central aperture in a circumferential hermetic sealed manner, thereby defining a secondary sealed air chamber between said split rubber duct plug and said end plate; and (e) a tube disposed within and projecting from said central aperture in said end plate, said tube being crimped in hermetically sealed engagement onto said cable.
Claim 14
Dependent Claim
20 words
The combination of claim 11 wherein said rubber out of which said split rubber duct plug is formed of neoprene.
Claim 15
Dependent Claim
15 words
The combination of claim 11 wherein said bentonite is in the form of compressed pellets.
Claim 16
Dependent Claim
15 words
The combination of claim 11 wherein said bentonite is tamped into said primary sealant chamber.
Claim 17
Dependent Claim
16 words
The combination of claim 11 wherein said bentonite is packed in a plurality of rupturable bags.
Claim 18
Dependent Claim
13 words
The combination of claim 15 wherein said rupturable bags are made of paper.
Claim 19
Dependent Claim
19 words
The combination of claim 11 wherein said sleeve, said end plate, and said crimped tube are formed of lead.
Claim 20
Dependent Claim
20 words
The combination of claim 11 wherein said crimped tube includes a sealing compound disposed between said tube and said cable.
Claim 21
Dependent Claim
22 words
The combination of claim 11 wherein said sleeve is secured to the said one end of said duct pipe by threaded engagement.
Claim 22
Dependent Claim
15 words
The combination of claim 11 wherein said duct pipe is a length of steel tubing.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |