MCINALLY, Gerald (Alvevegen 5, Bryne, N-4340, NO)
ØSTEVIK, John, Arild (Hottavikhagen 24, Hafrsfjord, N-4048, NO)
MCINALLY, Gerald (Alvevegen 5, Bryne, N-4340, NO)
|1. A cable cutting device (1) comprising a housing (6) and a transferring body (34), and where the cable cutter (1) comprises at least one radially
displaceable knife (48) , c h a r a c t e r i z e d i n that the one of the housing (6) or the
transferring body (34) is connected to the running sleeve (2) of a running tool and the other one of the housing (6) or the transferring body (34) is connected to the running shaft (4) of the running tool, and wherein the housing (6) , being radially displaceable relative to the transferring body (34), is provided with at least one longitudinal, slanting groove (32), and wherein a radially displaceable knife holder (46) with the knife (48) is arranged in the transferring body (34) , as the knife holder (46) abuts the housing (6) radially in the groove (32) .
2. A device according to claim 1,
c h a r a c t e r i z e d i n that the transferring body (34) is provided with a radial opening (44) complementary fitting the knife holder (46).
3. A device according to claim 1,
c h a r a c t e r i z e d i n that the transferring body (34) is provided with a central bore (40) running in to a slanted bore (42), as the slanted bore (42) exits at an in the housing (6) housing track (26) extending therethrough.
4. A device according to claim 1,
c h a r a c t e r i z e d i n that the knife holder (46) and the knife (48) are designed in one piece of material .
5. A device according to claim 1,
c h a r a c t e r i z e d i n that a cable (56) runs through the bores (40, 42) .
6. A device according to claim 1,
c h a r a c t e r i z e d i n that the cable (56) is cut through by the knife (48) when the cable cutter (1) is in its activated position.
This invention relates to a cable cutter. More particularly it concerns a cable cutter comprising a housing and a
transferring body, and which is arranged to be able to cut a cable in a borehole in the ground.
By cable is in this context meant any kind of a lengthy, flexible body being used, for example, for hoisting a tool up and down in the borehole, and for transferring fluids, energy, or signals in the borehole. Typical examples are wires, electrical cables, or so-called umbilicals.
On some occasions it will be necessary, for various reasons, to be able to cut a cable located in a borehole. For example a tool connected to the cable may be stuck in the borehole, and a cable torn relatively high up in the borehole will entail considerable difficulties later when the tool is to be "fished" out.
It is known to provide various tools with scissors, a
chemical or a pyrotechnical charge, which controlled or automatically shall be able to cut the cable down below by the relevant tool .
Equipment of this kind is superfluous if cutting the cable is not necessary, and such equipment entails thus usually unnecessary cost and time. The object of the invention, is to remedy or reduce at least one of the disadvantages of the prior art, or at least to provide a useful alternative to the prior art.
The object is achieved by the features disclosed in the below description and in the subsequent claims.
There is provided a cable cutter comprising a housing and a transferring body being characterized in that the housing, being axially displaceable relative to the transferring body, is provided with at least one longitudinal, slanted groove, and wherein a radially displaceable knife holder with a knife is arranged in the transferring body, as the knife holder is radially abutting the housing in the groove.
By slanted is meant that the groove has a different depth at its end portions, typically relative to the cable cutter central axis.
The cable cutter may, if needed, be threaded on to the cable and lowered down to the desired depth in a borehole before it is activated. The cable cutter may of course also accompany a tool down in the borehole when the tool is lowered for the first time.
The transferring body may be provided with a radial opening complementary fitting the knife holder. The knife holder may thereby be displaced radially in the opening, while the knife holder is displaced along the slanted groove.
The transferring body may be provided with a central bore running in to a slanting bore, as the slanting bore exits at a housing track in the housing running therethrough. A cable, if desired to be cut, may run through the bore and the housing track. The knife holder and the knife may be designed in one piece of material .
The cable cutter may be designed to be able to be connected to a running sleeve and a running shaft of a running tool. It is both practically and economically advantageous that the cable cutter may be connected to a well -proven and widespread tool if it is necessary to use the cable cutter.
The cable is cut through by the knife when the cable cutter is in its activated position. Reference is made to the detailed description part of the application for an
explanation to the cable cutter mode of operation.
In a preferred embodiment the cable cutter comprises two knives being radially displaced against each other and thereby cut the cable together. The knife holders may be provided with a shear pin holding them in their passive position until the housing is displaced relative to the transferring body by a predetermined force. The knife may, in not shown alternative embodiments, comprise a semi -ball shaped rotary knife, a rotatable knife blade or other
appropriate knife designs.
The cable cutter may, given enough room, be dimensioned and designed such that the cable may be laid in from the side. It is thereby not necessary to thread the cable cutter on to the cable to cut the cable.
The device according to the invention provides a cable cutter that may be sent down into the borehole to cut the cable at the desired level after such a need has turned up. The cable cutter is adapted to known activating equipment available in many places where drilling of holes in the ground takes place . In the following is described an example of a preferred embodiment illustrated in the accompanying drawings, wherein:
Fig. 1 shows a side view of a cable cutter in accordance with the invention;
Fig. 2 shows a section I -I in Fig. 1;
Fig. 3 shows a section from Fig. 2 to a larger scale;
Fig. 4 shows a section III-III in Fig. 3;
Fig. 5 shows the same as Fig. 2, but after the cable has been cut .
In the drawings the reference numeral 1 indicates a cable cutter connected to a not shown running tool's running sleeve 2. The running sleeve 2 encircles and is axially displaceable relative to a running shaft 4 see Fig. 2.
More particularly the running sleeve 2 is connected to the housing 6 of the cable cutter 1 comprising a first housing sleeve 8, a housing joint 10, a second housing sleeve 12 and a housing nut 14. The components 2, 8, 10, 12 and 14 are joined in succession by means of respective threaded
connections 16, 18, 20 and 22.
The first sleeve 8 is designed with a bore 24 near one of its end portions facing away from the housing joint 10. The bore 24 fits complementary to the running shaft 4 being
displaceable in the bore 24. The first sleeve 8 is further given a longitudinal housing track 26 extending therethrough over a share of the length of the first sleeve 8. The housing track is thus in the housing 6. The housing joint 10 is provided with a joint opening 28 extending therethrough and has a parapet 30 on its end facing the housing nut 14.
The second housing sleeve 12 is designed with two
diametrically opposing, longitudinal grooves 32. The grooves 32 are slanted, as they are deeper near the housing nut 14 than at the housing joint 10.
A transferring body 34 having the same OD as the running shaft 4 is connected to the running shaft 4 by means of a threaded bolt 36. From the opposing end portion 38 of the transferring body 34 a central bore 40 runs inward in the transferring body 34. The central bore 40 meets a slanted bore 42 exiting at the housing track 26 of the first housing sleeve 8.
Near the end portion 38 the transferring body 34 is given two radial openings 44 extending therethrough and corresponding with the respective grooves 32 in the second housing sleeve 12.
In each of the openings 44 is placed a knife holder 46 being radially displaceable in the opening 44 and abutting the housing 6 in the groove 32 in the second housing sleeve 12.
The knife holders 46 are provided with one knife 48 each being fastened to the knife holder 46 by a bolt 50. The knives 48 are designed with an approximately semi-circularly shaped edge 52.
In this preferred embodiment example the knife holders 46 are provided with shear bolts 54.
A cable 56 is arranged in the cable cutter. The cable 56 runs through the bore 40, 42 and thereby between the knives 48. The cable cutter 1 is activated by the running sleeve 2 and thereby the housing 6 being displaced axially relative to the running shaft 4 and the transferring body 34. When the housing 6 is displaced relative to the knife holders 46, the knife holders 46 are displaced together with the knives 48 radially inward as the knife holders 46 are displaced towards a shallower portion of the grooves 52, until the transferring body 34 abuts the parapet 30 on the housing joint 10 see Fig. 5. The cable 56 is now cut.
Next Patent: A METHOD, A TOOL AND A DEVICE FOR COUPLING A LOAD TO AND FROM A HOIST LINE