This application claims priority to Finnish patent application 20116180 filed 25 Nov. 2011 and is the national phase of PCT/FI2012/051040 filed 30 Oct. 2012.
The invention relates to the method and apparatus for plastic pipe drilling according to the independent claims related thereto.
Regarding applications for use of so called plastic pipe drilling typically e.g. well drilling or e.g. forepoling come into question. An advantage of use of a plastic pipe in drilling is first of all the fact that plastic pipes are very light compared to steel pipes, thanks to which they also have more profitable transport costs and they are easier to handle at a construction site. Furthermore a plastic pipe is significantly cheaper than a corresponding steel pipe. A plastic pipe does not frost for that matter and when being mounted into the ground, it does not break the bits of crushers or drills, when the soil is later on being e.g. worked or drilled. Furthermore in caves or quarries, metal may not blend with broken rocks, which is why use of plastic pipes in drilling has a very remarkable meaning in that context as well.
Today significant problems are, however, related to plastic pipe drilling, which is why it is not possible to exploit the same to the extent that there is a need for or that there are possibilities in practice. This is among other things due to the fact that the present arrangements require first of all use of a steel pipe in the beginning of drilling, whereby it is only after that possible to start using in the drilling a plastic pipe to be coupled with the steel pipe e.g. by a screw joint and after that further plastic pipes to be coupled with each other one after the other. On the other hand solutions are being used, which are based on a screw joint coupling between a plastic pipe with a readymade threading and a casing shoe.
The former solution is not satisfactory first of all due to the fact that there is still a need for use of a steel pipe in the starting phase, whereby it is possible to exploit plastic pipes with preworked threadings only after the above phase. Use of plastic pipes with readymade threadings has, however, found out to be very difficult in practice, because a threaded part of a plastic pipe being coupled with a casing shoe made of steel easily gets cut due to differences in shapes of mutual threadings in the parts in question. The problems related to preworked threadings in plastic pipes are probably due to the differences of steel and plastic e.g. because of strength and thermal expansion characteristics thereof and the like reasons.
There have been efforts for exploitation of joint arrangements in plastic pipes with readymade threadings on the other hand by using a very long coupling stem in the casing shoe with necessary elasticity means, such as damping O-rings, despite of which a screw joint between a casing shoe and a plastic pipe to be carried out with reasonable costs has not been managed to accomplish so far. All the types of arrangements described above require rather massive arrangements in order to make sure a screw joint between the casing shoe and the plastic pipe, which is why they increase the manufacturing costs disproportionately and make use of the solutions in question significantly more difficult in installation work in practice.
It is an aim of the present method and apparatus for plastic pipe drilling to achieve a decisive improvement in the problems described above and thus to raise essentially the level of prior art. In order to carry out this aim, the method and apparatus according to the invention are mainly characterized by what has been presented below.
As the most important advantages of the method and apparatus according to the invention may be mentioned simplicity and efficiency of constructions and use enabled by the same first of all thanks to the fact that a mechanical joint between a casing shoe and a plastic pipe can be formed in a reliable manner during coupling thereof by mechanically working the casing part, such as by threading the same at the same time as the casing shoe is being installed on the plastic pipe. Thanks to the invention it is thus possible to exploit an unpreworked plastic pipe which e.g. comes so to say directly from a production line, and that does not require any kind of additional machining, such as e.g. a preworked threading, which is the case with the solutions according to present technique. Furthermore thanks to the invention the joint between the casing shoe and the plastic pipe becomes totally clearance free even when using a significantly shorter coupling stem in the casing shoe than being used presently, and the joint is not diverted to varying of load in the longitudinal direction of the screw joint, which is typical in coupling of plastic material and steel material with readymade threadings with each other by a screw joint. Thanks to the invention, in the plastic pipe drilling there is no need for exploiting a steel pipe in the beginning, either, nor an excessively long casing shoe for that matter, which for its part eliminates a risk of metal, which may break bits of crushers or drills, from getting drifted into the soil.
By the method and apparatus according to the invention it is thus possible to make economical productivity of drilling significantly more efficient thanks to lowering transportation costs and easier handling of the plastic pipes. By virtue of the invention it is furthermore possible to exploit use of e.g. food stuff plastics in a more effective manner than at present e.g. in well drilling, thanks to which drill wells can be made as long lasting as possible without a risk of the earth pipes being used to get rosted.
Other advantageous embodiments of the method and apparatus according to the present invention have been presented below.
In the following description the invention is being illustrated in detail with reference to the appended drawings, in which
The invention relates first of all to a method for plastic pipe drilling when using an apparatus e.g. of the type as shown in
As an advantageous embodiment of the method it is exploited when using a drilling apparatus, in which the drilling head I of the drilling unit 3 is formed of a first frame part 4a and a second frame part 5a, wherein drilling surfaces P1, P2 formed of end surfaces of the above frame parts are provided with drilling organs of the first and the second drilling means 4, 5, such as an integrated drilling part, separate drilling pieces, bits or like. The casing shoe 8 for its part is connectable with the second frame part 5a when needed by a joint arrangement L that enables a mutual rotative motion of the casing shoe 8 and the second frame part 5a and that limits mutual longitudinal movement of casing shoe. With reference to the advantageous embodiments as shown e.g. in
Furthermore as an advantageous embodiment of the method, in forming an internal or external joint surface 2a with respect to the casing part 2, an internal or external threading sleeve X1a, X1b is being exploited that is arranged in an integral manner at the end of the casing shoe 8, the sleeve having one or more chip removal grooves X2a or openings X2b.
As a further advantageous embodiment particularly according to
As a further advantageous embodiment of the method, an essentially unpreworked raw pipe preform is being used as the casing part 2 that is manufactured particularly for food stuff utilization preferably from PEH-, PVC-plastic or a like and/or from reinforced plastic, such as fibrereinforced plastic or a like.
On the other hand, the invention also relates to an apparatus e.g. according to the type as shown in
As an advantageous embodiment of the apparatus according to the invention, in the type implementations as shown e.g. in
In
In a further advantageous manner, the casing shoe 8 is provided with a threading end X1 with two or several ends in order to mount the casing shoe 8 at the end of the casing part 2 for achieving a screw joint between said parts through chipping, whereby the threading end X1 is provided with exhaust arrangements X2 for removal of chips.
Particularly in the advantageous embodiment shown in
As a further advantageous implementation, the threading end X1 of the casing shoe 8 comprises a machine thread, a square thread, a trapezoidal thread and/or a like. Correspondingly the casing part 2 comprises profitably an essentially unpreworked raw pipe preform, which is manufactured particularly for food stuff utilization preferably from PEH-, PVC-plastic or a like and/or from reinforced plastic, such as fibrereinforced plastic or a like.
It is clear that the invention is not limited to the embodiments shown or described above, but instead it can be modified within limits of the basic idea of the invention according to the operating purposes and needs at any given time. It is thus clear, that working of the casing part can be carried out e.g. by upsetting retaining shoulders therein by means in the casing shoe or by chipping the casing part in a manner differing from actual threading by planning it with the casing shoe. On the other hand the constructions of the drilling heads being illustrated in the appended drawings may vary in practice very much merely when being carried out with differing diameters. Instead of the type of embodiments shown e.g. in
Number | Date | Country | Kind |
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20116180 | Nov 2011 | FI | national |
Filing Document | Filing Date | Country | Kind |
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PCT/FI2012/051040 | 10/30/2012 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2013/076360 | 5/30/2013 | WO | A |
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5542483 | Edman | Aug 1996 | A |
5813484 | Ekstrom | Sep 1998 | A |
5964297 | Edman | Oct 1999 | A |
Number | Date | Country |
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WO-9317215 | Sep 1993 | WO |
WO-9529321 | Nov 1995 | WO |
WO-9706337 | Feb 1997 | WO |
WO-2009038513 | Mar 2009 | WO |
Entry |
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PCT/ISA/210—International Search Report—Feb. 21, 2013 (Issued in Application No. PCT/FI2012/051040). |
PCT/ISA/237—Written Opinion of the International Seraching Authority—Feb. 21, 2013 (Issued in Application No. PCT/FI2012/051040). |
PCT/IPEA/408—Written Opinion of the International Preliminary Examining Authority—Nov. 20, 2013 (Issued in Application No. PCT/FI2012/051040). |
PCT/IPEA/409—International Preliminary Report on Patentability—Feb. 26, 2014 (Issued in Application No. PCT/FI2012/051040). |
Number | Date | Country | |
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20140332276 A1 | Nov 2014 | US |