Hydraulic and earth engineering – Subterranean or submarine pipe or cable laying – retrieving,... – Submerging – raising – or manipulating line of pipe or cable...
Reexamination Certificate
1997-03-03
2001-08-07
Graysay, Tamara L. (Department: 3625)
Hydraulic and earth engineering
Subterranean or submarine pipe or cable laying, retrieving,...
Submerging, raising, or manipulating line of pipe or cable...
C405S154100, C254S134400, C254S13430R
Reexamination Certificate
active
06270288
ABSTRACT:
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a system for installing cable in a conduit, and deals more particularly with an apparatus in the form of a cable flushing lateral for improving passage of a towed array cable through a guide tube of a submarine.
(2) Description of the Prior Art
When deploying a towed array from a submarine, the towed array cable passes from a capstan within the submarine through a guide tube, or conduit, which communicates with the medium surrounding the submarine. The capstan pushes the towed array cable through the guide as the cable is payed out. To lower the frictional forces of the cable against the interior of the conduit, water is pumped into the guide tube in the direction in which the cable is payed out. The water inlet to the guide tube consists essentially of an angled T-fitting. The water flowing past the cable creates a drag on the cable and assists in pulling the cable through the conduit. However, the force of the water entering the T-fitting occasionally pushes the cable against the opposite side of the conduit causing the cable to hang up within the conduit. Additionally, some of the water entering the T-fitting is directed opposite the direction of cable travel, resulting in drag forces opposing cable pay out.
Other methods for assisting in passing a cable through a conduit are well known in the art. Kunze et al., U.S. Pat. No. 5,011,332, disclose the use of various cable profiles to produce turbulence which in turn promotes the movement of the cable within the conduit. The profiles essentially consist of radial projections extending from the cable jacket or channels cut into the jacket. Still other methods known in the art utilize drocjues or pigs attached to the end of the cable as in U.S. Pat. No. 4,856,937 to Grocott et al. and U.S. Pat. No. 4,185,809 to Jonnes. Fluid pressure against the drogue or pigs pulls the cable through the conduit. When the cable emerges from the end of the conduit, the drogue or pig is removed and the remainder of the cable can be drawn through the conduit. Such systems would be helpful in conveying the end of the towed array to the point of exit from the conduit but would provide no additional assistance to the continued pay out of the towed array beyond this point. Changing the profile of the towed array or adding drogues or pigs to the array would result in additional costs required to retrofit the towed array or the array handling equipment. Moreover, the increased drag, turbulence and noise that both these methods generate are counter productive to the function and purpose of a towed sonar array.
SUMMARY OF THE INVENTION
Accordingly, it is a general purpose and object of the present invention to provide an improved system for assisting in paying out a cable through a conduit which is less prone to the cable being pushed against the wall of the conduit.
Another object is to provide an improved system for assisting in paying out a cable through a conduit which is effective on cable having a round cross section.
A still further object is to provide an improved system for assisting in paying out a cable through a conduit which continues to assist cable pay out after the end of the cable has exited the conduit.
These objects are accomplished with the present invention by providing a cable flushing lateral in place of the T-fitting currently in use. The flushing lateral is in the form of a pipe within a pipe. The upstream end of the inner pipe is connected to the capstan side of the guide tube and the upstream end of the outer pipe is connected to a water supply. The downstream end of the outer pipe connects with the end of the guide tube which exits the submarine. The inner pipe has an open termination upstream from the outer pipe and guide tube connection, and the outer pipe is closed against the inner pipe at its upstream end. The cable extends through the guide tube and flushing lateral. As water flows into the outer pipe, it surrounds the inner pipe, flowing through the annulus created between the inner and outer pipes and becoming uniform in pressure and velocity. At the inner pipe termination, a uniform ring of water surrounds the cable and flows past the cable into the guide tube and out the exiting end of the guide tube. The flowing water surrounding the cable lubricates the cable and creates a drag on the cable which assists the capstan in paying out the cable through the guide tube. The uniform flow of the water exiting the annulus ensures that the cable is not pushed against the side of the guide tube. The drag on the cable is effective in assisting the capstan even for round cable cross sections and is not dependent on drogues, pigs, or other special shapes placed at the end of the cable.
REFERENCES:
patent: 4232981 (1980-11-01), Lee
patent: 4822005 (1989-04-01), Aleshire
patent: 5011332 (1991-04-01), Kunze et al.
patent: 5199689 (1993-04-01), Proud et al.
patent: 5240351 (1993-08-01), Holmberg
patent: 5246207 (1993-09-01), Horri et al.
Hollingsworth Troy A.
Lambert Kenneth D.
Weidenheft, III John H.
Gauthier Robert W.
Graysay Tamara L.
Lagman Frederick L.
Lall Prithvi C.
McGowan Michael J.
LandOfFree
Cable flushing lateral does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cable flushing lateral, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cable flushing lateral will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2527033