Patent EP0287225A1 successfully refreshed from Google Patents.
EP0287225A1
Expired / Lapsed
EP
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Optical fibre installation
Assignee: British Telecommunications PLC
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Filing: 1988-03-23
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Granted: —
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Expires: 2008-03-23
Abstract
Abstract An apparatus and method for introducing a transmission line (5) into a duct (1) through which it is to be propelled by viscous drag of a fluid propellant. A high local flow of fluid is created by inputting fluid, preferably compressed air, adjacent the input of the transmission line to the duct and bleeding a proportion of the fluid from the duct a short distance along from the input. This local flow provides the driving force to progress the transmission line along the first third of the duct against the hydrostatic potential. The extent of the venting via the bleed valve is controllable to control the driving force on the transmission line (5). This technique is especially useful for transmission lines including optical fibres.
Inventors
- 👤 Peter John Keeble
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 02:21
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/46; G02B6/50; G02B6/52
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
77 words
Apparatus for advancing a transmission line along a tubular installation passageway having a transmission line input end and a transmission line output end by the fluid drag of a fluid medium, the apparatus comprising an input for the transmission line, inlet means for admitting fluid medium to the installation passageway and at least one outlet means disposed downstream of the inlet means for discharging fluid medium substantially before the transmission line output end of the installation passageway.
Claim 2
Dependent Claim
77 words
Apparatus for advancing a transmission line along a tubular installation passageway having a transmission line input end and a transmission line output end by the fluid drag of a fluid medium, the apparatus comprising an input for the transmission line, inlet means for admitting fluid medium to the installation passageway and at least one outlet means disposed downstream of the inlet means for discharging fluid medium substantially before the transmission line output end of the installation passageway.
Claim 3
Dependent Claim
32 words
Apparatus according to claim 1 in which the inlet means and outlet means are provided on a tubular passageway adapted for connection to the transmission line input end of the installation passageway.
Claim 4
Dependent Claim
25 words
Apparatus according to claim 1 in which at least one of the inlet means and outlet means is provided by tapping into the installation duct.
Claim 5
Dependent Claim
21 words
Apparatus according to any preceding claim in which the outlet means is adjustable to discharge fluid medium at a varying rate.
Claim 6
Dependent Claim
30 words
Apparatus according to any preceding claim in which the outlet means is controlled to reduce the rate of discharge of fluid medium as the transmission line advances into the passageway.
Claim 7
Dependent Claim
27 words
Apparatus according to any preceding claim in which the outlet is arranged to be closed when the transmission line has advanced a predetermined distance into the passageway.
Claim 8
Dependent Claim
23 words
Apparatus according to any preceding claim in which the input for the transmission line and the inlet means are separate from each other.
Claim 9
Dependent Claim
37 words
Apparatus according to any preceding claim comprising a further outlet means downstream of said at least one outlet means and arranged to open and close in accordance with the advancement of the transmission line into the passageway.
Claim 10
Dependent Claim
21 words
Apparatus according to any preceding claim comprising means for inhibiting backflow of fluid medium towards the input end of the pasageway.
Claim 11
Dependent Claim
17 words
Apparatus according to any preceding claim in which the transmission line is introduced from a sealed unit.
Claim 12
Dependent Claim
15 words
Apparatus according to claim 9 in which the transmission line input comprises a restricted portion.
Claim 13
Dependent Claim
54 words
Apparatus according to claim 11 in which the restricted portion comprises a resilient plug having a bore for the passage of the transmission line and an extended lip portion surrounding the transmission line in the flow passage so that pressure from the fluid medium urges the lip portion to seal against the transmission line.
Claim 14
Dependent Claim
30 words
Apparatus according to any preceding claim in which the transmission line input end of the installation passageway is continuous with a transmission line output end of a preceding installation passageway.
Claim 15
Dependent Claim
16 words
Apparatus according to any preceding claim including means for introducing compressed gas via the inlet means.
Claim 16
Independent Claim
87 words
A method of advancing a transmission line along an installation passageway by the viscous drag of a fluid medium, the installation passageway having a transmission line input end and a transmission line output end, the method comprising the steps of admitting fluid medium to the passageway containing the transmission line and discharging fluid medium from the passageway through at least one outlet further along the passageway in the direction of advancement of the transmission line but substantially before the transmission line output end of the installation passageway.
Claim 17
Independent Claim
87 words
A method of advancing a transmission line along an installation passageway by the viscous drag of a fluid medium, the installation passageway having a transmission line input end and a transmission line output end, the method comprising the steps of admitting fluid medium to the passageway containing the transmission line and discharging fluid medium from the passageway through at least one outlet further along the passageway in the direction of advancement of the transmission line but substantially before the transmission line output end of the installation passageway.
Claim 18
Dependent Claim
32 words
A method according to claim 15 in which at least some fluid medium is admitted at an intermediate location on the installation passageway after the transmission line has passed the intermediate location.
Claim 19
Dependent Claim
28 words
A method according to claim 15 or claim 16 on which fluid medium is discharged from an intermediate portion of the passageway to constitute a temporary passageway termination.
References Cited (Backward Citations)
DE1934818A1
Cited
EP0108590A1
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DE3340972A1
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DE3409376A1
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GB2157019A
Cited
US4640576A
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FR2577724A1
Cited
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