DE29504367U1 - Device for tapping plastic pipes for supply lines - Google Patents

Description

PATENT ATTORNEY _# · .· . J : %
EUROPEAN PATENT &Agr;&Tgr;&Tgr;&bgr;&rgr;&Ngr;&Egr;.&khgr; ·..·*..*

. DR. WALTHER JUNIUS Hanover

WOLFSTRASSE 24 TEL. (&Ogr;511) 834S30

30S19 HANOVER FAX. (OSIt) 842124

18 March 1995 File: 1314

Immanuel Jeschke

St. Nikolaistrasse 4+5, 31157 Sarstedt
District of Heisede

Device for drilling plastic pipes
of supply lines

The invention relates to a device for drilling plastic pipes of supply lines, consisting of a saddle provided with a radially arranged nozzle in the form of a pipe half-shell, which is provided with a mat-shaped heating wire arrangement on its inner surface, and of an abutment in the form of a second half-shell, which is to be mechanically clamped together with the saddle.

Such a device is known. It is used where a branch is to be installed or a shut-off is to be made on a supply line made of plastic pipes that is in operation and under operating pressure. At this point, the saddle, which is shaped like a half-shell and is also made of plastic, is clamped to the pipe of the supply line, for which purpose an abutment in the form of a second half-shell is often used, which is mechanically clamped to the saddle. An electric current of a certain strength and voltage is then passed through the heating wire arrangement for a certain period of time.

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whereby the surfaces of the saddle and the pipe of the supply line that are in contact with one another are brought into the molten state and welded together. The device is now prepared for drilling a hole in the pipe of the supply line, which is carried out after placing a lock arrangement on the nozzle on the saddle and after inserting a drill into the nozzle.

Where the abutment is no longer required after the welding process, it can be dismantled for further use elsewhere. This is because the welding is generally carried out over such a large area that there is no risk of the saddle tearing off under the operating pressure of the supply line.

The heating wire arrangement can be arranged directly under the inner surface of the saddle, but it can also be manufactured as a separate mat in which the heating wires are embedded in a loop-shaped plastic layer. This mat is then inserted between the inner surface of the saddle and the outer surface of the tube before it is assembled.

This known arrangement has proven itself in operation where the nozzles on the saddle have a smaller inner diameter than the pipe to create branches. This known arrangement becomes critical where shut-off plugs have to be inserted into high-pressure supply lines that have the same inner diameter as the pipe of the supply line. This is because the welded surface between the axially parallel edges of the saddle and the nozzle is not sufficient to

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at this point to ensure that the supply medium does not leak out of the supply line.

The invention avoids the disadvantages of the prior art. It is the object of the invention to achieve a secure fit of the saddle on the supply line and thus an absolute seal at the location of the saddle using simple means and in a simple manner.

The invention consists in the fact that on both sides of the semi-circular part of the saddle, legs running parallel to the axis in tangential planes are integrally connected, that the inner wall of the saddle extends beyond the center plane of the plastic pipe and continues to run (approximately) tangentially in this area, that the side walls of the second half-shell run parallel to this area or at an acute angle of a small number of degrees, that the inner wall of the saddle in its part extending beyond the center plane of the plastic pipe and running parallel to the side walls of the abutment is also provided with a mat-shaped heating wire arrangement, that the inner wall of the saddle in its part extending beyond the center plane of the plastic pipe and running parallel to the side walls of the abutment is welded to the side walls of the abutment.

With this device, a secure fit of the saddle on the supply line and thus absolute tightness at the location of the saddle can be achieved with simple means and in a simple manner. This is because the abutment is connected to the pipe of the supply line and to

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the legs of the saddle are firmly welded so that a reinforcing ring is created around the pipe of the supply line from the saddle and the abutment, which ensures that the saddle fits securely and is leak-proof for life at the critical point.

It is useful if the saddle and the abutment can be clamped together for the welding process by mechanical clamping devices that exert a force component parallel to the side wall of the abutment and another force component perpendicular to the side wall of the abutment, so that during welding, when the surfaces of the saddle and the abutment have become molten, the parts to be welded are pressed together in such a way that no cavities form at the welding point.

These mechanical clamping devices can be, for example, collets or similar clamping tools.

It is very simple and practical if the clamping devices consist of a screw, a nut and a spring. These can then be easily removed again after the welding process.

For the mutual bracing of the saddle and the abutment by means of the clamping devices, it is expedient if holes are provided in these side walls that run at an angle to the surface of the side walls of the abutment and that are aligned with these holes in the legs of the saddle that extend beyond the middle.

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For the attachment of the clamping devices, it is advantageous if the holes in the side walls of the abutment and in the legs of the saddle extend through projections formed on them, which have the shape of diagonally divided cuboids.

For a very secure fastening of the saddle and abutment on the pipe of the supply line, it is advisable if the abutment is also equipped with a mat-shaped heating wire arrangement in the area of the half-shell-shaped contact surface on the pipe.

The arrangement of the heating wires is also important for good welding: Here it is advantageous if the mat-shaped heating wire arrangement of the saddle consists of two heating wires, which are guided in a zigzag shape, each forming an area of several long wire loops and then an area of short wire loops, both of which are offset by 180° from each other around the area in the extension of the pipe socket.

The connection of the two heating wires is expediently carried out in such a way that the end of one heating wire in the area of the long loops is clamped together with the end of the other heating wire in the area of the short loops in a clamping point, to which a wire of the supply line for electrical energy is also clamped.

It is also advantageous if the heating wire loops have different lengths in the area of short loops, with the shorter ones in the middle of the

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of this area.

The heating wires can run in their straight sections on circumferential lines perpendicular to the axis of the pipe or parallel to the axis.

To ensure reliable sealing against the leakage of supply medium from the pipe of the supply line, it is advisable to have a groove formed in the inner surface of the saddle around the area in the extension of the pipe socket to accommodate a sealing ring.

The essence of the invention is explained in more detail below using an embodiment shown schematically in the drawing. They show:

Fig.1 a cross section through the device at

Location of the saddle-supported support,

Fig.2 a cross section through the device at

Place behind the support carried by the saddle,

Fig.3 a side view of the device,

Fig.4 shows a layout diagram of the heating wires that heat the area between the saddle and the pipe.

The device for drilling plastic pipes 1 of supply lines consists of a saddle 3 provided with a radially arranged nozzle 2 in the form of a pipe half-shell, which is provided with a mat-shaped heating wire arrangement 4 on its inner surface, and of an abutment 5 in the form of a second half-shell, which can be mechanically connected to the saddle 3.

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The mat-shaped heating wire arrangement 4 can be incorporated into the inner surface of the saddle 3, but it can also consist of an independent mat made of plastic in which the heating wires are located.

This device is characterized by the fact that on both sides of the semicircular part 6 of the saddle 3 there are legs that run parallel to the axis in tangential planes

7 in one piece. As a result, the inner wall of the saddle 3 extends beyond the center plane of the plastic tube 1 and continues (approximately) tangentially in this area. The side walls

8 of the abutment 5 run parallel to this area or at an acute angle of a small number of degrees. The inner wall of the saddle 3 extends beyond the center plane of the plastic pipe 1 and runs parallel to the side walls 8 of the abutment 5. The parts of the saddle 3 that run parallel to the side walls 8 of the abutment 5, i.e. the legs 7, are also provided with a mat-shaped heating wire arrangement. This ensures that after the welding process, the inner wall of the saddle 3 in its part that extends beyond the center plane of the plastic pipe 1 and runs parallel to the side walls 7 of the abutment 5, i.e. the respective leg 7 on both sides of the saddle 3, is welded to the side walls 8 of the abutment 5.

For the welding process, the saddle 3 and the abutment 5 can be clamped together by mechanical clamping devices, which have a force component parallel to the lateral

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wall 8 of the abutment 5 and a further force component perpendicular to the side wall 8 of the abutment 5. 'It is simple and practical if the clamping devices consist of a screw 9, a nut 10 and a spring 11. For the attachment of this clamping device, it is advantageous if holes running diagonally to the surface of the side walls of the abutment 5 are provided in these side walls 8 of the abutment 5 and further holes aligned with these holes are provided in the legs of the saddle 3 that extend beyond the middle. It is advantageous if the holes in the side walls 8 of the abutment 5 and in the legs 7 of the saddle 3 extend through projections 12, 13 formed on them, which have the shape of diagonally divided cuboids.

To further increase the strength, the abutment 5 in the area of the half-shell-shaped contact surface 14 on the pipe is also equipped with a mat-shaped heating wire arrangement 15.

The mat-shaped heating wire arrangement 4 of the saddle 3 consists of two heating wires 16, 17, which are guided in a zigzag shape to form an area 18 of several long wire loops and an adjoining area 19 of short wire loops, both of which are arranged offset by 180° from one another around the area 20 in the extension of the pipe socket 2. The end of one heating wire 16 in the area 18 of the long loops is clamped together with the end of the other heating wire 17 in the area of the short loops in a clamping point 21, to which a wire of the supply line of electrical

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Energy is connected. The heating wire loops have different lengths in the area of short loops, with the shorter ones being arranged in the middle of this area.

In the inner surface of the saddle 3 around the surface 20 in the extension of the pipe socket 2 a groove 22 for receiving a sealing ring is formed.

18.March.1995 File: 1314

List of reference symbols

1 plastic pipe

2 nozzles

3 Saddle

4 Heating wire arrangement

5 Abutments

6 semi-circular part1

7 legs

8 Side wall

9 Screw

10 Mother

11 Spring

12 Approach

13 Approach

14 Contact surface

15 Heating wire arrangement

16 ■ Heating wire

17 Heating wire

18 Area of long wire loops

19 Area of short wire loops

20 Area

21 Terminal point

22 groove

Claims (10)

18 March 1995 File: 1314 EXPECTATIONS Device for drilling plastic pipes of supply lines, consisting of a saddle provided with a radially arranged nozzle in the form of a pipe half-shell, which is provided with a mat-shaped heating wire arrangement on its inner surface,
and an abutment in the form of a second half-shell, which is to be mechanically clamped together with the saddle,
characterized, that legs (7) running parallel to the axis in tangential planes are integrally connected to the semicircular part of the saddle (3) on both sides,
that the inner wall of the saddle (3) extends beyond the central plane of the plastic tube (1) and continues (approximately) tangentially in this area, that the side walls (8) of the abutment (5) run parallel to this area or at an acute angle of a small number of degrees,
that the inner wall of the saddle (3) in its part (7) extending beyond the central plane of the plastic tube (1) and running parallel to the side walls (8) of the abutment (5) is also provided with a mat-shaped heating wire arrangement, that the inner wall of the saddle (3) in its part extending beyond the central plane of the plastic tube (1) and running parallel to the side walls (8) of the abutment (5) »s et «ac* · " - 2 - 18 March 1995 File: 1314 is welded to the side walls (8) of the abutment (5). 2. Device according to claim t,
characterized, that the saddle (3) and the abutment (5) can be clamped together by mechanical clamping devices which exert a force component parallel to the side wall (8) of the abutment (5) and a further force component perpendicular to the side wall (8) of the abutment (5). 3. Device according to claim 1 and 2,
characterized, that the clamping devices consist of a screw (9), a nut (10) and a spring (11). 4. Device according to claim 1 and 2,
characterized, that holes are provided in the side walls (8) of the abutment (5) that run obliquely to the surface of the side walls (8-) of the abutment (5) and that holes are provided in the legs (7) of the saddle (3) that extend beyond the middle, in alignment with these holes 5. Device according to claim 1,
characterized, that the holes in the side walls (8) of the abutment (5) and in the legs (7) of the saddle (3) extend through projections (12, 13) formed thereon, which have the shape of diagonally divided cuboids. - 3 - 18 March 1995 File: 1314 6. Device according to claim 1,
characterized, that the abutment (5) in the area of the half-shell-shaped contact surface (14) on the pipe (1) is also equipped with a mat-shaped heating wire arrangement (15). 7. Device according to claim 1,
characterized, that the mat-shaped heating wire arrangement (4) of the saddle (3) consists of two heating wires (16, 17), which are guided in a zigzag shape and each form an area (18) of several long wire loops and adjoining this an area (19) of short wire loops, both of which are arranged offset by 180° from one another around the surface (20) in the extension of the pipe socket (2). 8. Device according to claim 7,
characterized, that the end of one heating wire (16) in the area (18) of the long loops is clamped together with the end of the other heating wire (17) in the area (19) of the short loops in a clamping point, to which a wire of the electrical energy supply line is also clamped. 9. Device according to claim 7,
characterized, - 4 - 18 March 1995 File: 1314 that the heating wire loops in the area (19) of short loops have different lengths, with the shorter ones being arranged in the middle of this area. 10. Device according to claim 1,
characterized, ■that in the inner surface of the saddle (3) around the surface (20) in the extension of the pipe socket (2) a groove (22) for receiving a sealing ring is formed.