Title: Method and apparatus for eliminating air flow in communications cables to assist in plug formation

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Claims: What is claimed as new is as follows:

1. In a communications cable system of the type including a tubular housing and wherein the interior of the housing is maintained under gas pressure above ambient pressure and normally experiences a gas flow through the housing in one direction from a first portion toward a second portion of slightly lower pressure; the method of forming a fluid and gas-tight plug in a first zone of the interior of said housing spaced intermediate said first and second portions by the injection of a plug of fluent gas impervious hardenable material in said first zone, said plug being subject to gas trails being forced therethrough prior to at least initial hardening of said material in the absence of substantially equal gas pressure within said housing on opposite sides of said plug, said method comprising:

a. establishing a closed external gas flow line communicated at its opposite ends with second and third zones of the interior of said housing intermediate said first and second pressurized portions and on opposite sides of said first zone,

b. introducing gas into at least the end portion of said external flow line which opens into said housing downstream from said first zone and at a rate and pressure sufficient to terminate the flow of gas through said first zone,

c. pouring a plug of hardenable fluent air impervious material into said first zone, and

d. thereafter maintaining said gas pressure on opposite sides of said plug equal throughout at least the initial curing period of said plug.

2. The method of claim 1 wherein said flow line includes a flow meter serially mounted therein; the maintaining of the gas pressure on opposite sides of said plug equal including monitoring said flow meter and adjusting the rate and pressure of gas introduced into said flow line to maintain a "no flow" reading of said flow meter.

3. The method of claim 2 wherein the introduction of gas into said flow line includes the introduction of gas under pressure into predetermined zones of both opposite end portions of said flow line on opposite sides of said flow meter.

4. The method of claim 3 including a bypass line connected in parallel with said flow line and with its opposite ends opening into the flow line between said predetermined zones and on opposite sides of said flow meter, said bypass line including a closed bypass valve therein and said flow line, intermediate said air flow meter and one of said predetermined zones, having an open shut-off valve therein;

e. and at least substantially simultaneously opening and closing said bypass and shut-off valves.

Other info:

Inventors: Viramontes, Javier R.

Application Number: 471131
Filing Date: 1974-05-17
Publication_date: 1976-05-25
Assignee:
Primary Class(es): 138/97 137/13, 138/89
Other Classes:
US Patent Ref:

2043227	Jun, 1936	Bennett	174/11.
2272734	Feb, 1942	Witt	138/94.
2276443	Mar, 1942	Wilson	138/89.
2320506	Jun, 1943	Bennett et al.	138/89.
2449271	Sep, 1948	Bennett et al.	174/11.
2510513	Jun, 1950	Mueller et al.	138/97.
3115163	Dec, 1963	Epps et al.	138/94.
3298398	Jan, 1967	Smith	138/94.
3310615	Mar, 1967	Bender	138/89.
3340336	Sep, 1967	Bender	138/89.
3472285	Oct, 1969	Ginsburgh et al.	138/97.
3789883	Feb, 1974	De Gregory	137/824.
3845789	Nov, 1974	Rohrer	138/97.

Other Refs:
Primary Examiner: Aegerter, Richard E.
Assistant Examiner: Bryant, III, James E.
Attorney: O'Brien; Clarence A., Jacobson; Harvey B.