Similarly, it is sometime necessary to position submarine trasponders to identify a particular section of the pipeline, once layed down. Also in this case the transponders are strapped to the pipe, and must be removed once the laying operation is completed.

2. Description of Prior Art This task is performed by an R. O. V. (Remotely Operated Vehicle) that goes to cut the straps connecting the pipeline to the buoy, that will surface and may be reused. Similarly, the R. O. V. can cut the straps connecting the transponder to the pipe, and can recuperate it. The problem is the fact that the R. O. V. cost is extremely high.

Summary of the Invention The present invention is relative to a disengagement device that can be part of the buoy or can be independent from it, containg both a coded remote control able to receive ultrasound signals or other types of control, as discussed later, and a mechanism that either estract blades to cut the straps, or self explosive bolts, or a mechanism similar to baggage or trunk locks, spring or explosion actuated.

Naturallly the spring loaded device must be pro-loaded and blocked before usage by a tooth that will be removed by remote control, unlocking the system, and allowing buoy's disengagement, emersion and recovery.

Obviously the remote control may also be activated mechanically, or though a signal sent

through a wire or through the pipe itself A similar device can be used, coupled to smaller size buoys, to recuperate also the transponders that are sometimes strapped to the pipe. In this case, the device can also be integrated with the transponder, that will be used as a two way submarine radio.

Brief Description of the Drawings.

Passing to the description of the Figures, Figure I shows a possible execution of the device, on which four slots used to strap the device to the buoy are present. Notice that one of the extremes is bulkier to host the remote control, its battery, the cutting blade ready to use, together with the unlocking mechanism, that can be actuated via solenoid, or by a chemical reaction (explosion).

The following Figure 2 shows a possible version of the device in which the pre-loaded spring acts on a rigid stucture connecting two wedges, causing with their displacement the exit of the blades and the cutting of the straps connecting the buoy to the pipe.

Passing to Figure 3, the device presents on one side self explosive bolts which are holding the straps through a simple slot, while on the other side a similar device is blocked by an open hook, that is freed by the explosion of the bolts. Figure 4 shows the device in a simpler and more economic version in which the self exploding bolts are substituited by a lock very similar to those utilized for closing luggages and trunks, and where the pre- loading mechanism can be a spring or explosive.

Figure 5 shows the device fixed to the buoy with straps, while the following shows device and buoy fixed to the pipe.

Figure 7 shows the disengagement phase during which the blades are cutting the straps, while the following 8 and 9 show the"animation"of the disengagement phase in the last two versions of the device.

Description of Preferred Embodiment.

The preferred embodiement is based on a mechanism which on one side presents an open slot in which the bolts used to tend the straps are located. On the other side a mechanism similar to a car trunk lock has been used, presenting a special shape that, at opening, not

only frees the end ring, but also pushes it out of the slot, ensuring the unlocking process.

This is shown in Figure 10.

For instance, in the measuring device used in the research that led to the present Patent Application (Figure 2), the six degrees of freedom are all rotational, but allow as well placing the two bodies in any reciprocal position. Similarly the six degrees of freedom of both the measuring device and the two fixator's portions can be set as described in US Patent n° 5,152,280 (Figure 3), or in any other configuration, as long as at least three rotational degrees are left.