US3499411A - Underwater buoy release - Google Patents

Description

March 10, 1970 H. J. SAVOIE 3,499,411

UNDERWATER BUOY RELEASE Filed April 5, 1968 FIG. 1,

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gw, b wfzfm United States Patent ()flice' 3,499,411 Patented Mar. 10, 1970 3,499,411 UNDERWATER BUOY RELEASE Hilbert J. Savoie, P.0. Box 98, Boutte, La.

Filed Apr. 5, 1968, Ser. No. 719,151 Int. Cl. B63b 21/52, 21/56; B63c 11/48 US. Cl. 114235 8 Claims ABSTRACT OF THE DISCLOSURE Once an underwater pipe line has been laid, it not infrequently becomes necessary to ascertain the exact location and course of the line either for the purpose of making repairs or for the purpose of assuring there is no encroachment from a proposed parallel line or for any of a number of other valid, technical reasons. When a line has been laid under water for months or evenyears, the fact that its original start and finish points are known and that its original course has been plotted is not much help in locating any particular portions of the line. Such lines silt over and may be moved due to tidal currents, hurricanes, earth movements and other phenomena. Such lines, in present practice, are laid at very considerable depths, which makes it impractical to have a diver walk the line, marking its location and from time to time releasing marker buoys either anchored adjacent the line or actually secured to the pipe line itself.

Accordingly, there have been developed a number of devices for indirectly detecting and signaling the location of a pipe line. These devices are known in the trade as shellfish and the details of their construction and operation have nothing whatever to do with the present invention.

It has been the practice heretofore to tow the shellfish along the bottom and when the shellfish signals the presence of a pipe line to send down a diver who anchors the buoy near the line or ties it to the line itself. This obviously is an extremely time-consuming and costly procedure and virtually an impossible procedure at the greater depths at which pipe lines today are laid.

It is an object of the present invention to provide a buoy release unit which may be towed by the mother vessel which is also towing the shellfish. The tow lines are arranged so that the releasing unit is towed in quite close proximity to the shellfish. When the shellfish signals that it is adjacent the pipe line, then, by use of the present invention, the simple closure of a switch on the mother vessel releases a marker buoy which, as will presently be described, anchors itself immediately adjacent the line.

It is a further object of this invention to provide in a device as aforesaid means whereby, after the release of one marker buoy, another can be sent down from the surface and will assume the same relationship to the releasing mechanism as the previously released marker.

It is a further object of this invention to provide in a device as aforesaid means for latching the marker holding means to secure the buoy until the latch means is released and also to provide resilient means for recocking the latch means to be ready for the next marker buoy to be supplied thereto.

The above and other objects will be made clear from the following detailed description taken in connection with the annexed drawing, in which:

FIGURE 1 is a general view showing a mother ship, a pipe line at sea bottom, with both a shellfish and the device of this invention being towed by the mother ship,

FIGURE 2 is a plan view of the marker releasing device; and

FIGURE 3 is a section on the line 3-3 of FIGURE 2.

Referring now to FIGURE 1, the mother ship is designated by the numeral 10. From the stern of the mother ship a line 12 runs down to a conventional shellfish 14 which, through conductors in the cable 12, is able to signal the mother ship whenever it encounters a pipe line 16.

A second cable 18 leads from the mother ship to the underwater buoy release device 20 which is the subject of this invention. A cable 22 is secured at one end to an anchor 24 and at the other end to a marker buoy 26. A loop 28 is formed in the cable 22 while the outfit is at the surface. The loop 28 surrounds the cable 22 and, after forming the loop, the free end of the cable is attached to the anchor 24. The assembly then slides down the cable 18 until the loop 28 engages the cable holder 48 on the release device 20, where it is held and towed with the device 20.

The signal from the shellfish 14 may be either visual or audible, or both, but it establishes that the shellfish is in very close proximity to the pipe line. When the signal is received, a switch 30 aboard the vessel 10 is closed to activate the release mechanism of the device 20 which is best shown in FIGURES 2 and 3. It will be clear to anyone skilled in the art that the signal from the shellfish may itself be used to close the switch 30. In many cases, however, human intervention to interpret the signal is desirable lest a false signal trigger the release mechanism prematurely or unnecessarily.

Referring now to FIGURES 2 and 3, the device 20 comprises an outer cylindrical shell 32 with a conical nose portion 34 to which the cable 18 is attached. Conductors 36 run through the cable 18 to the mother ship where the switch 30 may be used to complete a circuit through a battery or other source of energy 38.

Inside the shell 32 an annular disk 40 supports and guides a latch member 42. A pair of arms 44 are mounted on the disk 40 and at their free ends pivotally receive between them a disk 46 to which is attached a marker holding arm 48 which protrudes through the shell 32. Opposite the arm 48 a spring 50 is attached to the disk 46 and the opposite end of the spring 50 is connected to the shell 32. The rear end of the shell 32 is open so that all parts to the right of the disk 40 in FIGURE 3 operate in water. The latch member 42 in its passage through the disk 40 is loosely fitted to allow freedom of movement when operating in mud or sand.

An electromagnet 54 is mounted in the shell 32 forward of the disk 40 and has an armature 56 connected to the latch member 42. The magnet 54 and its connections are designed to operate while the magnet is wet. In such case, the magnet and its associated connections are uniquely coated or impregnated with suitable waterproof plastic. The armature 56 is given non-corrosive coating for the same purpose. At its opposite end the latch member 42 has a tip of reduced diameter 58 which engages in a notch 60 in the pivoted disk 46. Means not shown are provided to bias the latch member 42 toward latching position and restore it to that position once the magnet 54 is deenergized.

While the pair of cables 36 are shown as connecting directly to the magnet 54, only one of these actually is needed. It is perfectly possible to ground one conductor 36 to the shell 32 and to ground the other one to the hull of the mother vessel 10. In salt water the single connection will be just as effective but in fresh water operations both conductors are desirable.

Aboard the mother ship 10 the cable 22, which connects the buoy 26 to its anchor 24, is equipped with a hook at its free end. The hook is passed through a large nose ring on the anchor 24, then is passed around the cable 22 and drawn into a loop 28 several feet in length, then again passes through the nose ring of the anchor 24 and the hook is snapped on the ring. As previously noted, the entire outfit of anchor 24, the cable 22 and buoy 26 is then thrown overboard and the loop 28 formed in the cable 22 guides the combination down the cable 18, over the conical point 34 and into contact with the cable release 48.

It is very clear that the combination of anchor, cable and buoy, with the mother ship 10 under way, will exert a very considerable drag on the holder 48 so that when the magnet 54 is energized and the latch 58 withdrawn from the notch 60 in the disk 46, the tension of the spring 50 is easily overcome and the holder 48 drops down through a slot 48' to permit the loop 28 to slide completely away from the shell 32. The moment the loop 28 clears the holder 48, the spring 50 restores the holder to the upright position of FIGURE 3 and the magnet 54, being then deenergized, the latch 58 reenters the notch 60, making the handle 48 ready to take the next buoy assembly which as heretofore recited is then threaded onto the cable 18 and dropped overboard.

While certain specific embodiments of this invention have been disclosed herein, the invention is not to be limited to the precise details disclosed.

What is claimed is:

1. For use in conjunction with a pipeline detector towed adjacent sea bottom by a surface vessel: a device towed from said vessel in submersed position adjacent said detector; said device having means releasably to engage Cir and carry with said device a buoy, an anchor and a line connecting said buoy to said anchor, and means operable from said surface vessel for releasing said buoy, line and anchor from said device whereby to mark the location of the detected pipe line.

2. A device as set forth in claim 1, in which said buoy releasing means is electro-magnetic.

3. A device as set forth in claim 2, in which said elecrtomagnetic means is waterproofed.

4. A device as set forth in claim 1, in which said buoy retaining means comprises an arm pivoted within said unit and projecting through a slot in said unit.

5. A device as set forth in claim 4, including a latch to retain said arm in projecting position.

6. A device as set forth in claim 5, including resilient means biasing said arm to projecting position.

7. A device as set forth in claim 6, including electromagnetic means for disengaging said latch.

8. A device as set forth in claim 7, in which said electro-magnetic means is waterproofed.

References Cited UNITED STATES PATENTS 2,359,366 10/1944 Katcher et a1. 114235.2 3,035,285 5/ 1962 Squires 99 3,212,110 10/ 1965 Lombardo 114206 X 3,295,153 1/1967 Dessaw 98 MILTON BUCHLER, Primary Examiner J. L. FORMAN, Assistant Examiner US. Cl. X.R. 98, 9

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