WO2004057230A1

WO2004057230A1 - Device and method for plugging of a pipe

Info

Publication number: WO2004057230A1
Application number: PCT/SE2002/002447
Authority: WO
Inventors: Kai Heed
Original assignee: Tigerholm Innovation Ab
Priority date: 2002-12-23
Filing date: 2002-12-23
Publication date: 2004-07-08
Also published as: AU2002359220A1

Abstract

The present invention refers to a device for plugging of a pipe (1), preferably pressurised gas pipes, by inserting from one end of the pipe (1) an expandable plug (3) into the pipe (1) by using an extension tube (10) that is attached to the plug (3) by means of a bayonet coupling (12) and an Allen wrench (11) rotatably provided inside the extension tube (10). The plug (3) consists of two end walls (6a and 6b) with intermediate elastic material (7) and held together by an Allen screw (8) that may be rotated by the Allen wrench (11), the end walls (6a, 6b) of the plug (3) being squeezed together to expand the elastic material (7) against the inner diameter of the pipe (3) in order to seal the pipe (1).

Description

DEVICE AND METHOD FOR PLUGGING OF A PIPE

Technical Field of the Invention

The present invention relates to a device for plugging of a pipe, e.g. existing gas pipes of buildings that no longer demands gas. This is preferably effected from the end of the pipe in the building up to the boundary of the building plot by inserting an expandable plug in the pipe until the desired plugging position has been reached. Now, the plug is brought to expand by means of an operating rod constituting a jointed and flexible extension tube, in which a likewise jointed and flexible Allen wrench. The extension tube is attached to one end of the plug in by means of a bayonet coupling and the Allen wrench is in engagement with an Allen screw that it is allowed to rotate freely relative to one end wall of the plug and threaded in the other end wall. By rotating the Allen screw the end walls of the plug are brought to move towards each other and the flexible material that is present between the end walls, e.g. rubber, is forced out between the end walls until it completely fills the inner diameter of the pipe and seals against the gas flow. The end of the gas pipe that is located in the building is sealed by a packing box, through which the operating rod of the plug may be inserted to a desired position inside the pipe. The invention also relates to a method for plugging of a pipe.

Prior Art

From US-A-4, 529, 007 a device and a method for temporary plugging of a water pipe is previously known. Thereby, it is possible to execute soldering work on said water pipe. The device is introduced axially in the water pipe and comprises a plug that on one hand consists of an elastic body and on the other hand of two washers that may be brought to move axially towards each other while the elastic body expands radially. The mutual displacement of the washers is effected by means of a special tool that affects a drawbar to be displace axially, said drawbar carrying one washer. The device may be locked in expanded position of the plug. When the soldering work is finished the device is removed. From US-A-2, 588, 188 a device for blocking of a sewer line, the device being designed to be mounted via a riser that generally has an extension transverse to the sewer line. The device is equipped with a flexible tube that may be bent in a right angle. A plug is provided at one end of the tube while operating means are provided at the other end of the tube. The plug is provided in the sewer line while the operating means are provided in the area of the opening of the riser. Expansion of an elastic body of the plug is effected by an axial displacement of a cable that is connected to a plate that affects the elastic body. This device is also intended for temporary use only.

Objects and Features of the Invention A primary object of the present invention is to present a device of the type defined above, said device remaining in the pipe, i.e. it should permanently or at least during a longer time plug a pipe, e.g. a gas pipe.

A further object of the present invention is that the device should be extremely user-friendly.

Still on object of the present invention is that the device should comprise relatively seen few components, i.e. the device is relatively seen inexpensive.

A further object of the present invention is that the device should be detachable from the pipe.

At least the primary object of the present invention is realised by means of a device that has been given the features of the appending independent claim 1. Preferred embodiments of the invention are defined in the dependent claims.

Brief Description of the Drawings

A preferred embodiment of the invention will be described more in detail with the reference to the enclosed drawings, where:

Fig 1 shows the non-expanded plug under insertion into a gas pipe;

Fig 2 shows a detail of a non-expanded plug;

Fig 2A shows a section according to A-A in figure 2; Fig 3 shows the plug in expanded position; Fig 4 constitutes a section through a packing box that seals at the end of the pipe; Fig 5 shows a plugged pipe; and

Fig 6 shows the flexible joint between two operating rods.

Detailed Description of a Preferred Embodiment of the Invention

In figure 1 a gas pipe 1 is shown, the end of said gas pipe 1 terminating inside a wall 2 of a building. An expandable plug 3 is inserted into the pipe by means of a jointed operating rod 4 that extends through a packing box 5 that seals against the pipe and the operating rod. Figure 2 shows the expandable plug 3 in non-expanded position and consists of two end walls 6a and 6b where the space between the end walls is filled with an elastic material 7, e.g. rubber, and the end walls 6a, 6b being connected to each other by means of an Allen screw 8 that is threaded in the end wall 6a and free rotating in the end wall 6b. The Allen screw 8 is further sealed at the end wall 6b by means of a sealing 9. An operating rod 4 is attached to the end wall 6b, said operating rod 4 constituting an extension tube 10 and an inside said tube rotatably provided Allen wrench 11. The extension tube 10 is attached to the end wall 6b of the plug 3 by means of a bayonet coupling 12 and the Allen wrench 11 is axially locked to the extension tube 10 by means of set screws 13 that cooperates with a grooved washer 14 that is fixed to the Allen wrench 11. The end walls 6a and 6b are displaced towards each other by rotating the Allen screw 8 by means of the Allen wrench 11. The elastic material 7 is then forced to expand, as is shown in figure 3, until it seals against the inner side of the pipe 1.

The end of the extension tube 10 that projects through the packing box 5 is equipped with a key handle 14 for holding the extension tube 10 when the Allen wrench 11 is rotated by a suitable tool, see figure 4. The sealings 15 of the packing box against the pipe 1 and the sealing 16 against the extension tube 10 is also shown in figure 4.

Subsequent to the sealing of the pipe 1 by means of the plug 3 the extension tube 10 is rotated anticlockwise to release the bayonet coupling 12. The extension tube 10 and the Allen wrench 11 may be removed from the pipe 1 and the end of the pipe is equipped with a cover 17 as is shown in figure 5. The operating rod 4 is preferably manufactured in manageable lengths that, in dependency of possible bends of the pipe, are jointed to each other by means of a flexible joint according to figure 6. A helical spring 18 is at both ends fixed to a cylindrical bushing 19 whose outer diameter, as well as the outer diameter of the helical spring 18, corresponds to the outer diameter of the extension tube 10. The bushing 19In is locked to the end of the extension tube 10 by means of a locking screw 21 and the ends of the Allen wrench 11 are joined to a universal joint 22 that is fixed to the ends of the Allen wrench 11 by means of locking screws 23. Within the scope of the present invention it is also possible to remove the remaining plug 3. In connection therewith the operating rod 4 is inserted and the extension tube 10 of the operating rod 4 is brought into engagement with the end wall 6a by means of the bayonet coupling 12. In order to effect this without complications it may be suitable to have some kind of mutual guidance (not shown) between the end wall 6a and the extension tube 10. In connection with the activating of the bayonet coupling 12 the Allen wrench 11 is also received by the Allen screw 8. By rotating the Allen wrench 11 in suitable direction the end walls 6a and 6b will be distanced from each other. This means that the elastic material 7 will contract and looses its engagement with the inner side of the pipe 1.

Feasible Modifications of the Invention

In the embodiment described above in the device comprises an Allen screw 8 that is brought to cooperate with an Allen wrench 11. It is of course feasible within the scope of the invention that the screw is equipped with a head having external gripping surfaces and in such a case the head is brought to cooperate with a suitable socket wrench.

In the embodiment described above the extension tube 10 is attached to the end wall 6b of the plug by means of a bayonet coupling 12. Within the scope of the present invention it is also feasible to have different couplings between the extension tube and the end wall and in exemplifying and non-restricting purpose a thread coupling may be mentioned.

Claims

1. Device for plugging of a pipe, preferably a pressurised gas pipe, the device comprising an expandable plug (3) that consists of two end walls (6a, 6b) that are held together by an axially extending means (8), and that the space between the end walls is filled with an elastic material (7), that the axially extending means (8) is connected to the end walls (6a, 6b) in such a way that the mutual distance between the end walls (6a, 6b) is changed when the axially extending means (8) is rotated around its longitudinal centre axis, c h a r a c t e r i z e d in that the plug (3), in order to rotate the axially extending means (8), is equipped with means for detachable coupling to an activating means (10, 11).

2. Device according to claim 1, c h a r a c t e r i z e d in that the axially extending means constitutes an Allen screw (8) that is in threaded engagement with one end wall (6a) and is allowed to rotate freely in the other end wall (6b), and that the activating means (10, 11) comprises an Allen wrench (11) for rotation of the Allen screw (8).

3. Device according to claim 1 or 2, c h a r a c t e r i z e d in that, to effect insertion of the plug (3) into the pipe (1), the plug (3) is fixed to an extension tube (10) by means of an bayonet coupling (12), an Allen wrench (11) being rotatably provided in the extension tube (10) and axially guided by means of set screws (13) threaded in the extension tube, said set screws (13) cooperating with a grooved cylindrical washer (14) that is fixed to the Allen wrench (11) .

4. Device according to claim 3, c h a r a c t e r i z e d in that the extension tube (10), with the Allen wrench (11), is provided in jointed lengths by means of an flexible helical spring (18) that at both interior ends is fixed to cylindrical bushings (19) having an outer diameter that, as well as the outer diameter of the helical spring (18), is not exceeding the outer diameter of the extension tube (10) .

5. Device according to claim 4, c h a r a c t e r i z e d in that the bushings are locked to the ends of the extension tubes (10) by means of locking screws (21), and that the Allen wrenches (11) are joined together by means of an universal joint (22) that is fixed to the ends of the Allen wrenches (11) by means of locking screws (23) .

6. Device according to any of the claims 3-5, c h a r a c t e r i z e d in that the extension tube (10) extends through a packing box (5) at the end of the pipe, said packing box (5) having sealings (15) against the inner diameter of the pipe as well as sealing (16) against the extension tube (10).

7. Method for plugging of pipes, preferably pressurised gas pipes, where an expandable plug (3) is inserted into a pipe (1), said expandable plug comprising an elastic material (7) between two mutually displaceable end walls (6a, 6b), c h a r a c t e r i z e d in that activating means (10, 11) are activated, ' said activating means (10, 11) being detachably attached to the plug (3), that the elastic material (7) expands in radial direction to seal against the inner side of the pipe (1), and that the activating means (10, 11) then are removed from the plug (3) .

8. Method according to claim 7, c h a r a c t e r i z e d in that the activation of the activating means (10, 11) comprises transfer of rotation between an Allen screw (8) and an Allen wrench ( 11 ) .