In any case, the invention will be better understood with the aid of the following description, with reference to the appended schematic drawing representing, as an example, a form of execution of this flexible tubing for a rotary-percussion drilling device:
FIG. 1 is a partial view of a flexible tubing according to the present invention, seen in section passing through its axis;
FIG. 2 illustrates a use of this flexible tubing on a rotary-percussion drilling device.
FIG. 1 represents a section of a flexible tubing indicated in its entirety by reference number 2, this figure more particularly showing the region of one end of this flexible tubing 2.
In its running portion, the flexible tubing 2 has a diameter of less than 30 mm, and it consists here of a conventional hydraulic hose 3 on the outside, and of a tube 4 of the stapled type on the inside. The hydraulic hose 3, that may have two, three or four braids, provides the seal and the pressure-resistance necessary to carry the hydraulic fluid, such as high-pressure water, that in this case supplies a downhole hammer 5 (see FIG. 2).
The stapled tube 4 provides the flexible tubing 2 with the rigidity necessary to transmit the thrust and the rotary torque to the downhole hammer 5.
At both ends of the flexible tubing 2 fittings 6, of which one is visible in FIG. 1, are provided. Each fitting 6 comprises an external annular fitting end-piece 7, a cylindrical insert 8 engaged inside the stapled tube 4, and an external skirt 9 fitted around the end of the hydraulic hose 3. The fitting 6 thus constituted has a rigid connection with the stapled tube 4 which allows the thrust and the rotary torque to be transmitted via this fitting 6, particularly for transmitting this thrust and this torque to the downhole hammer 5.
FIG. 2 illustrates, very schematically and as an example, a rotary-percussion drilling device using the flexible tubing 2 described above. This drilling device comprises a carrying vehicle 10, having a chassis 11 and wheels 12 that allow it to move in a mine gallery 13 that may be of low height H. On the chassis 11 of the vehicle 10 a mobile platform 14 is mounted that can be moved in translation lengthwise on the chassis 11. The mobile platform 14 carries a high-pressure water pump 15 that is connected, via the flexible tubing 2, to the downhole hammer 5 which, during use, is brought to the location of the hole to be drilled, particularly in the “roof” of the mine gallery 13.
At the point of departure of the flexible tubing 2 are provided an electrovalve 16 allowing water to travel at high pressure to the tubing 2 and motorized means 17 for rotating the flexible tubing 2.
In the present case, the first fitting 6 of the flexible tubing 2 is fitted to the motorized means 17 for rotating this flexible tubing 2. The second fitting 6 of the flexible tubing 2 is fitted to the rear end of the drill body belonging to the downhole hammer 5. Therefore, the flexible tubing 2, with its fittings 6, provides the transmission to the downhole hammer 5:
- of the thrust F exerted by the motorized movement in translation of the mobile platform 14; and
- of the rotary torque C imparted by the motorized means 17.
As it goes without saying, the invention is not limited to the single form of execution of this flexible tubing for a rotary-percussion drilling device that has been described above as an example; on the contrary, it embraces all the variant embodiments and applications thereof respecting the same principle.
It is thus in particular that there would be no departure from the context of the invention:
- by an inversion of disposition in the structure of the flexible tube, the hydraulic hose occupying in this case an internal position (and no longer external) and the stapled tube then occupying an external position (and no longer internal);
- by changes of detail, concerning for example the constitution of the fittings of the flexible tubing, in particular its end-pieces that may be of any type;
- by the use of any equivalent components, in particular by replacing the stapled tube inside the flexible tubing with an internal contiguous coil spring whose design would also make it possible to transmit the thrust and the rotary torque;
- by adapting this flexible tubing to rotary-percussion drilling devices of various types, as concerns both the downhole hammer and the system of supplying pressurized fluid and forward travel, the platform that is mobile in translation in particular being replaceable by a reel mounted on the carrying vehicle and causing the flexible tubing to travel forwards;
- finally, in a similar kind of idea, by replacing the mobile platform with a conventional drilling slide, in which case the assembly formed by the rotation means, the flexible tubing and the downhole hammer may be moved by the slide.
Patent Application
20080061621
