Background Pipelines are built by using pipes that are connected to each other. Pipes with female and male ends are often used for this purpose. The female end has a sleeve (radial extension) allowing the male end of a pipe to be inserted into the female end of another pipe. The inside of the sleeve may have a gasket to ensure the tightness of the connection.

Joining of pipes is typically carried out as part of earthworks. Typically, a pipeline section with an open male or female end has already been laid at the bottom of a trench. Typically, a pipeline section is placed at the end of this section so that the end of the pipe to be connected is aligned with the end of the section already laid. After this, using an excavator, an iron bar, a spade or similar, the end of the pipe to be connected is inserted into the end of the section already laid. Such work is slow and requires a great deal of physical effort. Furthermore, plastic pipes are fragile, especially in sub-zero temperatures, which means that in cold weather, they are easily ruptured when joined by means of iron bars or spades using the known method. The purpose of the invention is to present a tool allowing a single person to join the pipes described above.

Tools for the same purpose are known as prior art from such publications as US36531 15. One problem with the solution detailed in this publication is that the part of the tool gripping the pipes to be joined does not necessarily have a sufficiently strong hold on the pipe and, as a result, the tool slips on the pipe surface. Furthermore, for the tool to function properly, both pipes must be precisely aligned with each other. The tool is also sensitive to dirt and mud, which are a common problem at earthworks sites. A brief description of the invention

In the tool described below, some of the problems associated with the known method have been solved by adding to the pipe gripping instrument at least one angle, which ensures a strong hold on the pipe. A corresponding embodiment is described in more detail in Patent Claim 1. Other advantageous embodiments of the tool are described in Dependent Claims 2 - 25. Advantageous embodiments of the gripping instrument are described in detail in Dependent Claims 2 - 1 1 . The grip can also be applied to pipes of different sizes by means of an adapter or adapters, as detailed in Dependent Claims 12 - 19. The grip of the tool has also been made more effective by employing a mechanism that causes the gripping instrument to have a strong hold on the pipe surface. This mechanism is described in Dependent Claims 20 - 24.

Description of the drawings FIG 1 a-1 c show photographs of a pipe tool,

FIG 2a-2b show side elevation views of a tool,

FIG 3 shows the shape of the inner surface of the second gripping instrument of the tool and how the second gripping instrument grips the pipe,

FIG 4a-4f show top elevation views of the shapes of the inner surface of the second gripping instrument,

FIG 5a shows how an adapter is employed in the joining of smaller- sized pipes,

FIG 5b-5d show an adapter,

FIG 6a shows an end elevation view of the parts of a tool,

FIG 6b shows a second adapter,

FIG 7a shows a side elevation view of a force transfer component of a tool,

FIG 7b shows an end elevation view of a force transfer component of a tool,

FIG 7c-7e show glide rail solutions for the force transfer component, FIG 8a shows the gripping part of a tool in a closed position, FIG 8b shows the gripping part of a tool in an open position,

FIG 8c shows the gripping part of a tool in the minimum intermediate position,

FIG 9a-9d show how two pipes are joined by means of the tool, and FIG 10a-10d show how two pipes are separated by means of the tool.

Detailed description of the invention In FIG 1 a-10d, the device 500, or the pipe tool 500, is shown in projections, in which the directions Sx, Sy and Sz are perpendicular to each other in accordance with the ordinary right-handed coordinate system. The direction Sx accords with the longitudinal direction of the tool, which is also the longitudinal direction of the pipes 600 to be joined (see FIG 1 a). When the tool is used, the direction Sz is essentially upwards. The term 'vertical direction' refers to the direction during the use of the tool. The concepts indicating directions, such as 'downwards', 'from downwards', 'upwards' and 'from upwards', also relate to the directions during use. Unless otherwise stated in this specification, the outer diameter of the pipe 600 means the cross section of the pipe, as measured from the pipe's outer surface; the cross section being perpendicular to the longitudinal axis of the pipe and transversally located at a pipe section outside the sleeve 612 (see FIG 9a). The cross section of the pipe 600 is typically circular in shape.

FIG 1 a - 1 c show the tool 500, or the device 500, for joining and separating two pipes 600. With reference to FIG 1 a-1 c, 2a and 6a, the device 500 comprises the first gripping instrument 1 10, such as a collar, plate or similar. The first gripping instrument 1 10 is open from below so that it can grip the pipe 600 from above, which can, for example, be done by placing the tool so that it straddles the pipe 600. The first gripping instrument 1 10 matches the outer surface of the pipe 600 so that it can grip the pipe 600 from above, for example, for at least 150 degrees. On the one hand, 'match' means that a piece with the same outer diameter as the pipe fits from below into the space 295 provided for the pipe in the first gripping instrument 1 10. On the other hand, 'match' means that the female end sleeve 612 of the pipe 600 (see FIG 6a) does not fit into the space 295 provided in the first gripping instrument 1 10. In that case, the first gripping instrument 1 10 can be placed so that it straddles the pipe 600 and so that the pipe 600 can be fitted into the space 295 provided in first the gripping instrument 1 10 and the first gripping instrument 1 10 can be steadied against the sleeve 612 of the pipe 600 in the longitudinal direction Sx (see FIG 9a-9d and 10a-10d). As shown in the drawings, the upper part of the first gripping instrument 1 10 may be of semicircular shape; the radius of the semicircle being equal to the outer surface radius of the pipe 600, or no more than 20%, such as no more than 10%, larger. It must, however, be smaller than the outer radius of the sleeve 612. If the device 500 comprises the second adapter 580, its inner surface radius may be of the size mentioned above.

The device 500 also comprises the second gripping instrument 210 (see FIG 1 a-1 c and 2a), such as a collar, plate or similar. In specific embodiments, the second gripping instrument 210 comprises the first gripping part 212 and the second gripping part 214 (see FIG 8a-8c). The second gripping instrument 210 may be in the closed position Ai (FIG 8a) or in the open position A2 (FIG 8b). The second gripping instrument 210 may be locked in the closed position Ai. In that case, the pipe 600 can be locked in the space 290 provided in the second gripping instrument 210 (see FIG 8a).

When the second gripping instrument 210 is in the closed position Ai , its inner surface matches the outer surface of the pipe 600. In this position Ai, the inner surface of the gripping instrument 210 can be matched with the outer surface of the pipe 600 for at least 210 degrees. When the inner surface of the second gripping instrument matches the outer surface of the pipe 600, the inner surface of the second gripping instrument (210, 212, 214) is transversally concave with respect to the pipe, as, for example, shown in FIG 8a-8c. If the device 500 com prises the first adapter 550, its inner surface matches the outer surface of the pipe 600.

As described above, the pipe has the outer diameter d, such as a cross section. This dimension means the cross section outside the sleeve 612. With reference to FIG 8a, in a specific embodiment, when in the closed position, the second gripping instrument 210 is open from below; the opening having the first width wi (see FIG 5a). The advantage of this is that even if the pipes to be joined are lying on the ground, the gripping instrument 210 can be easily locked as the gripping instrument will also remain open when in the closed position; the opening having the width wi. The first width is smaller than the outer diameter d of the pipe 600 so that a sufficiently strong grip on the pipe 600 can be ensured. Advantageously, the first width wi is not larger than the pipe's outer radius. Advantageously, the first width wi is at least 2 cm or at least half of the outer radius. In the closed position Ai, the second gripping instrument 210 may be open from below for the full longitudinal length Sx. In the closed position Ai, the second gripping instrument 210 matches the outer surface of the pipe 600 so that the pipe 600 can be moved in the longitudinal direction Sx by moving the second gripping instrument 210 in the longitudinal direction Sx.

With reference to FIG 5b, when in the open position A2, the second gripping instrument (210, 212, 214) is open from below; the opening having the second width W2 and this second width W2 being at least equal to the outer diameter d of the said pipe 600. In that case, the second gripping instrument 210 of the device 500 can also be placed so that it straddles the pipe 600 and so that the second gripping instrument 210 can grip the pipe 600 from above. As is obvious, when in the open position, the second gripping instrument 210 is open from below for the full longitudinal length Sx. The gripping instruments 1 10, 210 can grip the ends of two pipes in a manner described below. In order for the pipe ends to be joined or separated, the device 500 also comprises the devices 300 for moving the first gripping instrument 1 10 and the second gripping instrument 210 with respect to each other at least in the said longitudinal direction ±Sx. The devices 300 for moving the first gripping instrument 1 10 and the second gripping instrument 210 with respect to each other are shown for example in FIG 2a and 7a-7e.

As the pipe 600 is intended to be moved by means of the gripping instruments 1 10, 210, the second gripping instrument 210 must have a sufficiently firm hold on the pipe 600. It should be noted that, as the first gripping instrument 1 10 is steadied against the sleeve 612, the grip of the first gripping instrument 1 10 on the pipe 600 is not of critical importance. For this reason, in a specific embodiment, the inner surface of the first gripping instrument 1 10 (or the outer edge of the space 295) is smooth in the longitudinal direction Sx of the pipe 600.

A smooth inner surface is easier to manufacture than, for example, a surface that is angled and/or concave in the direction Sx. Furthermore, if the grip of the first gripping instrument 1 10 on the pipe 600 is not sufficiently strong, the first gripping instrument 1 10 is steadied against the sleeve 612 of the pipe 600 and not against the outer surface of the pipe 600.

At the same time, the second gripping instrument 210 specifically grips the outer surface of the pipe 600. With reference to FIG 3 and 4a-4f, it has been noted that the grip can be strengthened by having at least the first angle 402 on the inner surface 400 of the second gripping instrument 210, 212, 214, or by having in the second gripping instrument 210 the protrusion 402, which projects towards the pipe 600 or, when the pipe 600 is not in the space 290 for the pipe, the said first angle 402 projects towards the space 290 for the pipe.

It has been particularly noted that such an angle 402 provides a particularly firm grip on the pipe 600 if the said first angle 402 is sharp. In a specific embodiment, the radius of curvature of the first angle 402 is no more than 0.5 mm, such as no more than 0.3 mm. In a specific embodiment, the first angle 402 is less than 90 degrees (see FIG 4a). In an advantageous embodiment, the first angle 402 arises at the intersection of the inner surface 400 and the first edge surface 412 of the second gripping instrument 210 in which the edge surface 412 comprises a direction parallel to the radius of the pipe 600 at each of its points (see FIG 4a - 4c), and the angle referred to above is sharp in the meanings referred to above. The edge surface 412 does not necessarily comprise the direction of the pipe radius, as shown in FIG 4d and 4e. Advantageously, in that case, the first angle 402 is directed away from the centre of the second attachment instrument 210, as shown in FIG 4e. The direction of the first angle 402 means the direction of the straight line S1 halving the first angle 402. With reference to FIG 4a-4e, advantageously, the straight line S1 is obliquely towards the space 290 for the pipe 600 and away from the centre of the attachment instrument 210. Alternatively, the straight line S1 may be directly towards the space 290 for the pipe (FIG 4f).

Advantageously, the inner surface 400 of the said second gripping instrument 210, 212, 214 is concave. Here, concavity also means concavity in the said longitudinal direction Sx of the pipe 600. Such a concave inner surface is shown in FIG 3 and 4a-4e. For example, the second gripping instrument 210, 212, 214 may become thinner towards its centre, as shown in FIG 4a-4e.

Advantageously, the said inner surface 400 is concave so that the said first angle 402 is located at the first edge of the second gripping instrument 210, 212, 214 and the inner surface 400 of the said second gripping instrument 210, 212, 214 forms the second angle 404 projecting towards the said space 290 for the pipe; this angle being located at the second edge of the second gripping instrument 210, 212, 214. Furthermore, the concave section of the inner surface 400 of the second gripping instrument 210, 212, 214 is located between the first angle 402 and the second angle 404. The second angle 404 is also a protrusion of the second gripping instrument 210. Here, 'concave section' means a concave section in the longitudinal direction Sx of the pipe, as described above (see FIG 3 and 4a-4e). Advantageously, the second angle 404 is also sharp in the above meanings of the radius of curvature. Advantageously, the second angle 404 is also directly towards the pipe 600 or obliquely towards the pipe 600 and away from the centre of the second gripping instrument, as described above for the first angle 402. For example, the straight line S2 halving the second angle 404 may be directed in this manner.

Most typically, the device 500 would be used to join plastic pipes, in which case the grip provided by the angles 402, 404 on the pipe 600 should not be too strong so as not to break the pipe 600. For this reason, the depth ad of the concave section of the inner surface 400 should be within a suitable range. In a specific embodiment, the depth d of the concave section of the inner surface 400 is between 1 mm and 2 mm. The depth ad means the length of the projection of the line segment between the bottom of the concave section and the apexes of the angles 402, 404 where the said projection is a right-angle projection for a level where the normal is the length of the pipe (see FIG 4a). Similarly, the height of the first angle 402 or the first protrusion 402 of the second gripping instrument 210, as measured from the bottom of the concave section in the direction referred to above is advantageously between 1 mm and 2 mm. Similarly, the height of the second angle 404 or the second protrusion 404 of the second gripping instrument 210, as measured from the bottom of the concave section in the direction referred to above is advantageously between 1 mm and 2 mm. In a specific embodiment, the thickness t of the second gripping instrument is least 3 mm, such as 3 mm - 8 mm or 3 mm - 5 mm. Thickness t means the thickness radial to the pipe. In that case, together with the said depth ad, the second gripping instrument 210, 212, 214 is still sufficiently stable in its middle section. To some extent, the grip provided by the angles 402, 404 may also depend on the length of the second gripping instrument 210, 212, 214 in the longitudinal pipe direction Sx. Advantageously, the length L of the second gripping instrument 210, 212, 214 in the longitudinal direction Sx (see FIG 2a and 2b) is at least 10 mm and no more than 100 mm, more advantageously 20 mm - 60 mm, such as 30 mm - 50 mm.

With reference to FIG 2a and 2b, in a specific embodiment, the second gripping instrument 210, 212, 214 comprises the devices 230 for attaching the adapter 550 to its inner surface 400. In a specific embodiment, the opening 230 is provided in the second gripping instrument 210, 212, 214 for attaching the adapter 550. Similarly, the adapter 550 can be attached to the second gripping instrument by means of a screw or similar through the opening 230.

FIG 5a shows the second gripping instrument 210, 212, 214 with the adapter 550, 552, 554 attached to it. The adapter 550 may comprise the first part 552 and the second part 554, as shown in FIG 5a and 5b. Alternatively, the adapter 550 may only comprise one part (FIG 5c). The adapter 550 may comprise the devices 553, 554 for attaching the adapter 550 to the second gripping instrument 210, 212, 214. For example, the adapter part 552 may comprise the threaded bar 553, which may be brought through the opening 230 provided in the second gripping instrument. The bar may have external threads. The adapter part 552 may be attached to the second gripping instrument 210, 212, 214 by means of a nut or similar, such as a butterfly nut. Similarly, the second part 554 may comprise the threaded bar 555. Alternatively or in addition, the adapter 550 may have an embedded nut or similar, which is equipped with internal threads. In that case, a separate screw, bolt or similar can be brought through the opening 230 to attach the adapter.

The adapter 550 can be used to adjust the space 290 for the pipe 600 so that the pipe 600 can be fitted into it. Typically, the second gripping instrument 210 is dimensioned for a pipe of a specific size, as shown above, and the adapter 550 is measured for a smaller pipe. The outer surface 560 of the adapter matches the inner surface 400 of the second gripping instrument 210. The inner surface 565 of the adapter matches the outer surface of the pipe 600. Advantageously, the groove 562 is provided on the outer surface 560 of the adapter. The groove 562 matches the inner surface 400 of the gripping instrument 210. What is said above of the shape of the inner surface 400 of the second gripping instrument 210, 212, 214, also applies advantageously to the shape of the inner surface 565 of the adapter 550.

In order to ensure a sufficient grip of the adapter 550 on the pipe 600, it has been advantageously manufactured from a relatively hard material. In a specific embodiment, the adapter 550 contains a material with a hardness of at least 70 ShA (Shore A scale); more advantageously at least 50 ShD (Shore D scale). In a specific embodiment, the adapter 550 only contains a material or materials with a hardness of at least 70 ShA; more advantageously at least 50 ShD. Most advantageously, the adapter contains a polymer material (such as rubber or plastic) with a hardness of at least 70 ShA; more advantageously at least 50 ShD.

With reference to FIG 5d, the adapter 550 may comprise the metal part 556, such as two metal parts 556a and 556b. The metal part 556 is arranged to touch the pipe 600 when the tool 500 is in the closed position Ai. In a specific embodiment, the parts of the adapter 550 that are made of polymer will remain between the first metal part 556a and the second metal part 556b in the said longitudinal direction Sx. If the tool comprises the adapter 550, the tool also advantageously comprises the second adapter 580, by means of which the first gripping instrument 1 10 can be adjusted for the pipe 600. FIG 6b shows an example of a second adapter 580. The second adapter 580 may have a groove on its outer surface so that the inner surface of the first gripping instrument 1 10 (see FIG 6a) can be matched with the outer surface of the second adapter 580. The first gripping instrument 1 10 may comprise the devices 130 for attaching the second adapter 580 to the inner surface of the first gripping instrument 1 10. The opening 130 may serve as such a device. The second adapter 580 may comprise the devices for attaching the second adapter 580 to the inner surface of the first gripping instrument 1 10. A screw and/or a nut may be used as such devices, as described above with regard to the adapter 550. What is said above of the material and materials of the adapter 550, also applies to the second adapter 580. To join the pipes, it is advantageous that, when necessary, the movement of the gripping instruments 1 10, 210 is not precisely longitudinal; in other words, the movement may also have a slight transverse component of specific size. This makes it possible to join the pipes 600 even if they are not fully aligned. This can, for example, be achieved by means of the rails 322, 324 which move with respect to each other and are only loosely mode- locked to each other and only in two directions. The rails constitute the first longitudinal support 320 (see FIG 1 a-1 c and 7a-7d). The first rail 322 can be slid with respect to the second rail 324 longitudinally over a distance that is adequate for joining the pipes 600. This distance may, for example, be at least 5 cm, at least 7 cm or at least 10 cm. Alternatively, the distance may, for example, be no more than 50 cm.

The first longitudinal support 320 is attached to the first gripping instrument 1 10 and to the second gripping instrument 210. Each of the rails 322, 324 is separately attached to only one of the gripping instruments 322, 324 directly. Through the support 320, the instruments 1 10, 210 are attached to each other so that they can be moved, as described above.

With reference to FIG 7c, in a specific embodiment, the first rail 322 constitutes the inner part 322 of the longitudinal support 320 and the second rail 324 constitutes the outer part 324 of the longitudinal support 320. The inner surface 325 of the outer part 324 is loosely matched with the outer surface 323 of the inner part 322 so that at least in some places the gap g exists between the said surfaces 323, 325. The gap g may, for example, be of such size that the average of the gap, when calculated across the examination points, is at least 1 mm and no more than 15 mm. For example, in the embodiment of FIG 7c, the first rail 322 (the inner part) may have a square-shaped outer cross section of 20 mm, while the second rail 324 (the outer part) may have a square-shaped outer cross section of 25 mm. With a wall thickness of 3 mm, the gap g between these rails 322, 324 in the directions Sx and Sy is 2 mm throughout.

With refence to FIG 7d, the rails 322, 324 can also be designed differently with respect to each other. For example, the first rail 322 may be shaped like an I-beam that is locked in the groove of the second rail 324. With reference to FIG 7a, the bar 322 and the pipe 324 may also be used as the rails 322, 324; the bar 322 being placed inside the pipe 324. Advantageously, as shown in FIG 4c, the outer surface of the pipe 324 is shaped like a polygon, because in that case other parts of the device 500 can be more easily attached to the pipe 324.

The lever 310 has proved an advantageous device 300 for moving the first gripping instrument 1 10 and the second gripping instrument 210 with respect to each other and for ensuring dirt-resistance and easy usability of the device 500. With reference to FIG 7a and7b, in a specific embodiment, the devices 300 for moving the first gripping instrument 1 10 and the second gripping instrument 210 with respect to each other also comprise at least the second longitudinal support 330, 332. As shown above, the first longitudinal support 320 is attached to the first gripping instrument 1 10 and the second gripping instrument 210, as described above. In FIG 2a and 2b, the second longitudinal support 330 is directly attached to the second gripping instrument 210. Furthermore, the second longitudinal support 330 is directly attached to the lever 310. Advantageously, the second longitudinal support 330 is attached to the second gripping instrument 210 at a point that in the vertical direction Sz is not in the centre of the space 290 provided for the pipe 600. The distance of the said point from the level that comprises the directions Sx and Sy and the longitudinal centre axis of the space 290 may be at least 1 cm or at least 2 cm. This causes the gripping instrument 210 to have a tendency to slightly bend around the transverse axis Sy when moved in the longitudinal direction Sx. This ensures a stronger grip of the gripping instrument 210 on the pipe 600.

Advantageously, the second longitudinal support 330 is attached to the second gripping instrument 210 at its first attachment point and to the lever 310 at its second attachment point. There is a line segment between the first and the second attachment point and this line segment is parallel to the longitudinal direction ±Sx or forms with this ±Sx an angle of less than 10 degrees or less than 5 degrees. Here, 'angle' means the smaller of the two angles that the directions +Sx and -Sx form with the said line segment. In that case, the force pulling the pipes towards each other or the force drawing them apart will be appropriately directed at the pipe 600.

Furthermore, the devices 300 for moving the first gripping instrument 1 10 and the second gripping instrument 210 with respect to each other in the longitudinal direction comprise the lever 310, which is directly attached to the part of the first longitudinal support 320 that is directly attached to the first gripping instrument 1 10, such as the rail 322. Correspondingly, the lever 310 is attached to the second gripping instrument 320 through the second longitudinal support 330.

The lever attachment points (316 and 331 ; and/or 318 and 333; FIG 4b) for the longitudinal supports 320, 330 constitute the lever support points. In that case, the lever can be used to move the longitudinal supports 320, 330 with respect to each other in the longitudinal direction Sx in a manner know per se. As shown in FIG 4a and 4b, advantageously, three longitudinal supports (320, 332, 334; see FIG 1 c and 4b) are used. At least one of them is, advantageously the rail-based support described above, in which case the two other supports may be bars or similar, as shown in the drawings.

In order to ensure a strong grip of the second gripping instrument 210 on the pipe 600, the second gripping instrument 210 can be advantageously and easily locked in the said closed space Ai . With reference to FIG 8a-8c, to solve this problem, the second gripping instrument 210 is in a specific embodiment also arranged

- to be in the minimum intermediate position Ao (see FIG 8c) and to

- move to the open position A2 (see FIG 8b) from the closed position Ai (see FIG 8a) only through the minimum intermediate position A o; or so that at some point between these two positions (A2, Ai), the second gripping instrument is in the said minimum intermediate position Ao.

With reference to FIG 8a, in a specific embodiment, when in the said closed position Ai , the second gripping instrument 210 is open from below; the opening having the first width wi. In other words, the gripping instrument 210 constitutes an opening when viewed downwards in the direction -Sz from the pipe 600 (or from the corresponding space 290; see FIG 8a); this opening having, in the transverse direction Sy, the first width wi , which in the longitudinal direction Sx continues for the full length of the gripping instrument 210. With reference to FIG 5c, in the minimum intermediate position Ao described above, the second gripping instrument 210 is open from below; the opening having the minimum width wo. The smallest width wo corresponding to the minimum intermediate position Ao is smaller than the said first width wi . With regard to locking the function, the smallest width wo may be zero but considering the purpose of use, it is advantageous if the minimum width wo, too, is larger than zero, for example, 1 cm, 2 cm or 3 cm.

With this dimensioning and what is said above of the movement between positions Ai and A2 through position Ao, it is possible to create the technical effect that, when the pipe 600 is located in the space 290 in the closed position Ai , the shape and diameter of the pipe themselves tend to keep the second gripping instrument 210 in the closed position Ai . Especially the movement to the minimum intermediate position Ao and/or through it to the open position A2 requires a certain amount of force. The second gripping instrument 210 is therefore designed so that it tends to remain in the closed position Ai .

With reference to FIG 8a-8c, in a specific advantageous embodiment, the second gripping instrument 210 comprises the first gripping part 212 and the second gripping part 214. Each of the gripping parts 212, 214 is separately arranged to turn with respect to the longitudinal axis Sx. The space 290 for the pipe 600 remains between the first gripping part 212 and the second gripping part 214.

In a specific embodiment, the device 500 comprises the gripping arrangement 200, which comprises the intermediate section 240. Connected pivotally to the intermediate section, the gripping arrangement also comprises the first gripping support 222 and the second gripping support 224. During use, the gripping supports may be essentially arranged in the vertical direction Sz.

When the pipe 600 is gripped by means of the gripping instrument 210, the first gripping support 222 is turned with respect to the intermediate section 240 (for example, in FIG 8b and 8a, anti-clockwise), which causes the gripping support 222 to establish a contact with the first gripping part 212 at the first contact point Pi . When the gripping support 222 is turned further, it can be employed to turn the first gripping part 212 into the closed position Ai . On the other side, the gripping takes place in a similar manner by means of the gripping support 214 and the gripping part 214. The gripping support 222, 244 (one or both) may comprise the protrusion 232, 234. With the protrusion, an appropriate contact between the gripping supports 222, 224 and the gripping parts 212, 214 can be secured. The strength of the contact is determined by the length of the protrusion 232, 234. The length of the protrusion is the distance by which the protrusion 232, 234 projects from its gripping support 222, 224. Advantageously, the protrusion can be adjusted, because the device may experience wear during use. The adjustment can, for example, be by means of a nut and/or a threaded pin, in which case, for example, the length of the protrusion 232, 234 can be changed by turning the body of the protrusion 232, 234. The strength of the grip of the second gripping instrument 210 (or its parts 212, 214) on the pipe 600 can be adjusted by adjusting the length of the protrusion.

As shown in FIG 8a and 8b, turning the gripping supports 222, 224 with respect to the intermediate section 240 may, for example, be by means of the locking pieces 252, 254. In a specific embodiment, the gripping arrangement 200 also comprises the first locking piece 252. The first locking piece is connected pivotally to the first gripping support 222 at a point where the intermediate section 240 will remain (a) between the joint of the first locking piece 252 and the first gripping support 222 and (b) the first contact point Pi. The gripping arrangement also comprises the second locking piece 254, which is also connected pivotally to the first locking piece 252 at the pivot point N. By turning the locking pieces 252, 254, the gripping supports 222, 224 can also be turned and the second gripping instrument can be moved between positions Ai and A2, and optionally also between them and Ao, as shown in FIG 8a-8c.

The gripping arrangement also comprises the stopper 256. The purpose of the stopper 256 is to limit the angle between the first locking piece 252 and the second locking piece 254 to such a level that in the said closed position Ai the inner surface of the gripping instrument 210 provides the space 290 for the pipe 600 that has the outer diameter d. In other words, the stopper prevents the locking pieces from, for example, turning to an excessively low position in FIG 8a, which would cause the space 290 to become too large. The stopper 256 can, for example, be provided by designing the locking pieces 252, 254 in an appropriate manner (cf. FIG 8a-8c). The locking piece 252, 254 can also be equipped with a handle 260 or similar to facilitate its use. The handle 260 may also act as the stopper 256 or part of the stopper 256. It has been noted that when appropriately designed, the handle 260 may be used to facilitate the locking of the device 500. Especially when the handle 260 continues in the transverse direction (Sy, Sz) across the said pivot point N, the handle 260 acts as the lever arm for turning the locking piece 252 and/or 254. The lever 310 and/or its extension 305, such as the handle 305, has two functions. Firstly, pipes can be moved with respect to each other by means of the lever 310, 305. Secondly, the lever 310, 305 may be used to mark the location of the end of the pipe 600. For both functions, it is advantageous that the lever 310 or the combination of the lever 310 and its extension 305 are of adequate length. In a specific embodiment (a), the length of the lever 310 or (b) the combined length of the lever 310 and its extension 305 is at least 50 cm; more advantageously, at least 75 cm.

The device 500 is particularly well suited for joining and separating wastewater pipes. Smaller pipes may also be joined by hand without tools.

The forces required for joining larger pipes may of such magnitude that the device described here does not provide an optimum solution for such work.

Advantageously, the first gripping instrument 1 10 and the second gripping instrument 210 of the device 500 are so dimensioned, optionally with the adapters 550, 580, that the device 500 is adapted for joining and separating two pipes 600 that have an outer diameter of between 100 mm and 210 mm.

The outer diameter of the pipes 600 may, for example, be 1 10 mm, 160 mm or

200 mm. FIG 9a-9d again illustrate how pipes are joined by means of the device 500. In FIG 9a, the pipes 600a, 600b to be joined are placed close to each other so that they can be joined. The male end 620 of the pipe 600b is placed close to the female end 610, or sleeve 612, of the pipe 600a. In FIG 9b, the device has been made ready for joining the pipes so that the first pipe 600a is placed in the space 295 provided in the first gripping instrument 1 10 and the second pipe 600b is placed in the space 290 provided in the second gripping instrument 210. As shown in the drawings, the second gripping instrument 210 is designed so that if the instrument 210 is not in the locked position Ai , the instrument 210 can freely open in a manner determined by the outer surface of the pipe 600b when the device 500 is placed so that it straddles the pipes 600a, 600b. Furthermore, the sleeve 612 of the pipe 600a will remain between the first gripping instrument 1 10 and the second gripping instrument 210. As shown in FIG 9c, the second gripping instrument 210 is locked in the locked position Ai , by for example pressing the handle 260 (see FIG 8a-8c). Furthermore, as shown in FIG 9c, the pipes 600a and 600b are connected by turning the lever 310 in a clockwise direction, which causes the lever 310 to move the gripping instruments 1 10, 210 towards each other, with the first gripping instrument 1 10 gripping the sleeve 612 of the pipe 600a and the second gripping instrument 210 being locked on the outer surface of the pipe 600b; especially by means of the first angle 402 (FIG 4a - 4f). Following this, as shown in FIG 9d, the second gripping instrument 210 can be unlocked by, for example, lifting the handle 260. The device 500 straddling the pipe can be lifted and the joint can be covered with soil. The device can, for example, be placed so that it straddles the female end of the recently installed pipe 600b to wait for the next joining operation.

With reference to FIG 7c, an embodiment of the device 500 comprises an indicating device 328 such as the laser 328. The purpose of the indicating device 328 is to indicate the direction of the pipe line. In that case, the indicating device 328 is arranged to show where the upper edge of the next pipes should be located.

With reference to FIG 10a-10d, the separating of the pipes is essentially carried out in reverse order. It should be noted that at the start of the separation of the pipes, the device 500 should only be placed on the second pipe 600b so that the sleeve 612 of the first pipe 600a will remain on the same side with respect to the gripping instruments 1 10, 210. The first gripping instrument 1 10 should also kept close to the sleeve of the first pipe 600a but should nevertheless remain straddled on the second pipe 600b.