WO2005084860A1

WO2005084860A1 - Device for cutting a pipe

Info

Publication number: WO2005084860A1
Application number: PCT/NL2005/000131
Authority: WO
Inventors: Gilbert Rezette
Original assignee: Idea Heavy Equipment B.V.; Sindorf Trading Holland B.V.
Priority date: 2004-02-23
Filing date: 2005-02-23
Publication date: 2005-09-15
Also published as: NL1025550C2

Abstract

A device for cutting a pipe (5), which device comprises cutting means (16) for cutting the pipe (5) in a direction perpendicular to the longitudinal direction thereof, as well as counter pressure means (6) for exerting a counter pressure on the pipe (5) during the cutting thereof, said cutting means including a knife (6) that is movable between a position of rest and an operative position, a special feature being the fact that the device comprises a parallelogram-type jack (12) that is connected to the knife (6), which jack (12) can be moved between a retracted position and an extended position by driving mean (14) said knife (5) occupying its position of rest in the retracted position of the jack (12) and occupying its operative position in the extended position of the jack (12).

Description

DEVICE FOR CUTTING A PIPE

The invention relates to a device for cutting a pipe, which device comprises cutting means for cutting the pipe in a direction perpendicular to the longitudinal direction thereof, as well as counter pressure means for exerting a counter pressure on the pipe during the cutting thereof, said cutting means including a knife that is movable between a position of rest and an operative position. Such a knife is also called a guillotine knife in practice. It is noted that the invention generally pertains to the cutting of round, elongate structures, in particular cylindrical objects, such as tubes,^" pipes and beams and the like. Hereinafter, the term "pipe" will be used, which term is not intended to limit the invention. Furthermore it is noted that the invention in particular relates to the cutting of (very) heavy thick- walled pipes, such as oil pipes, into pieces for removal thereof, which involves (very) high forces.

Such a cutting device is known from US patent publication No. 4,519,235 (LaBounty) . This known, hydraulically driven cutting device consists of a shear including two mutually pivotable shear blades for cutting in particular heavy steel pipes into short lengths. A drawback of the cutting device that is known from the aforesaid US patent is the fact that it is hardly capable, if at all, of cutting thick-walled pipes having wall thickness of more than 5 cm, for example, into short lengths in an efficient manner.

The object of the invention is to obviate this drawback of the prior art, and in order to accomplish that object a device of the kind referred to in the introduction is according to the invention characterized in that the device comprises a parallelogram-type jack that is connected to the knife, which jack can Joe moved between a retracted position and an extended position by driving means, said knife occupying its position of rest in the retracted position of the jack and occupying its operative position in the extended position of the jack. This makes it possible to cut or shear thick-walled steel objects, such as parts of the jacket of drilling platforms (the so-called "decommissioning") or oil pipes and/or gas pipes so as to enable dismantling or sealing thereof, or oil pipes and/or gas pipes on a pipe-laying ship. In particular the diamond-shaped jack makes it possible to cut or shear pipes having a wall thickness of more than 5 cm.

In a preferred embodiment of a device for cutting pipes according to the invention, the jack comprises mutually pivotable arms, wherein the knife is connected to the jack near a pivot point. Preferably, the driving means are likewise connected to the jack near a pivot point. In a preferred variant, the knife is connected to a first pivot point and the driving means are connected to a second pivot point, said first and said second driven points being located on the same arm.

In another preferred embodiment of a device for cutting pipes according to the invention, the jack can be moved between the retracted position and the extended position by hydraulic driving means. In principle it is also possible to use pneumatic , electrical or mechanical driving means, however.

In another preferred embodiment of a device for cutting pipes according to the invention, the device comprises a receiving space of at least substantially U-shaped cross-section for the pipe, wherein the device includes retaining means for retaining the pipe in said space. More in particular, said retaining means include an arm that is pivotally connected to a leg of said U-shaped cross-section, wherein said arm is pivotable between an open position, in which said receiving space is open, and a closed position, in which said receiving space is closed. It is preferred to drive the arm by hydraulic means, in which case the hydraulic driving means engage the arm near one end thereof.

In another preferred embodiment of a device for cutting pipes according to the invention, said counter pressure means comprise said arm.

The invention will now be explained in more detail with reference to figures in a drawing, which schematically show the device according to the invention in perspective view, each from a different side elevation.

Fig. 1 shows a frame 1 of U-shaped cross-section. The legs 2,3 of the U-shaped cross-section define a receiving space 4 for receiving an oil pipe 5. An arm 6 is mounted to the leg 2 of the U-shaped cross-section, which arm is pivot-mounted to the frame 1 by means of a pivot pin 7. Thus the arm 6 can be pivoted from an open position, in which the oil pipe 5 can be placed in the receiving space 4 (as shown) , to a closed position, and vice versa. In the closed position (not shown) the oil pipe 5 is retained in the receiving space 4. The receiving space is bounded by upright ribs 8. The arm 6 is driven by a hydraulic piston/cylinder device 9, the piston 10 of which engages one end of the arm 6 functioning as a lever. As is indicated in Fig. 1, the piston/cylinder device 9 is mounted to the leg 2 of the U-shaped cross-section.

Near the base 11 of the U-shaped cross-section, a "linkage"^'" in the form of a diamond-shaped jack 12 or a parallelogram- type jack 12 is mounted in the frame 1. The jack 12, which comprises four mutually pivotable (lifting) arms 13, is movable between a retracted position and an extended position under the influence of hydraulic drive means 14. The hydraulic drive means 14 is connected to the jack 12 near the pivot point 15, whilst a guillotine knife 16 is connected to the jac -12 near a pivot point 17. In the present case, the two pivot points 15,17 are located on the same arm 13. In the retracted position of the jack 12, the guillotine knife 16 is in a position of rest, whilst in the extended position of the jack 12 the guillotine knife 16 is in an operative position, i.e. a cutting or shearing position. In Fig. 1 , the guillotine knife 16 is shown in the operative position. The guillotine knife 16 exerts a progressive (constantly increasing) force on the oil pipe 5.

Fig. 2 shows the device of Fig. 1 from a different side elevation, in which like parts are indicated by the same numerals.

It is noted that the invention is not limited to the embodiment as shown herein, but that it also extends to other preferred variants that fall within the scope of the appended claims.

Claims

1. A device for cutting a pipe, which device comprises cutting means for cutting the pipe in a direction perpendicular to the longitudinal direction thereof, as well as counter pressure means for exerting a counter pressure on the pipe during the cutting thereof, said cutting means including a knife that is movable between a position of rest and an operative position, characterized in that the device comprises a parallelogram-type jack that is connected to the knife, which jack can be moved between a retracted position and an extended position by driving means, said knife occupying its position of rest in the retracted position of the jack and occupying its operative position in the extended position of the jack.

2. A device according to claim 1, wherein said jack comprises mutually pivotable arms, and wherein the knife is connected to the jack near a pivot point.

3. A device according to claim 2, wherein the driving means are connected to the jack near a pivot point.

4. A device according to claim 2 and 3, wherein the knife is connected to a first pivot point and the driving means are connected to a second pivot point, said first and said second driven points being located on the same arm.

5. A device according to any one of the preceding claims 1- 4, wherein the jack can be moved between the retracted position and the extended position by hydraulic driving means .

6. A device according to any one of the preceding claims 1- 5, wherein the device comprises a receiving space of at least substantially U-shaped cross-section for the pipe, and wherein the device includes retaining means for retaining the pipe in said space.

7. A device according to claim 6, wherein said retaining means include an arm that is pivotally connected to a leg of said U-shaped cross-section, and wherein said arm is pivotable between an open position, in which said receiving space is open, and a closed position, in which said receiving space is closed.

8. A device according to claim 7, wherein the device comprises hydraulic driving means for driving the arm.

9. A device according to claim 8, wherein said hydraulic driving means engage the arm near one end thereof.

10. A device according to claim 7, 8 or 9, wherein said counter pressure means comprise said arm.