AU538560B2 - Pipe coupling - Google Patents

Description

Pipe coupling

Background of the invention

This invention relates to a pipe coupling for connecting branch pipes to a feed-pipe without requiring flow interruption in the feed-pipe.

Prior art

Such pipe couplings are known in a great number of different embodiments, as described, for example, in GB-PS 1 034 138, FR-PS 7 122 557 and US-PS 3 983 897, where for connection between the feed-pipe and the branch pipe a passageway is formed in the pipe coupling. The present invention comprises more precisely, as known previously, coupling parts, which sealingly embrace the feed-pipe, a cylindric guide passageway extending in one coupling part, a piston sealingly inserted in the guide passageway, which piston at its inner end is provided with a knife-shaped cutting-up member and formed with a passageway for flow connection between the feed-pipe and the branch pipe connected to the coupling part, in such a manner, that in assembled position of the coupling parts a portion of the feed-pipe projects in radial direction into the guide passageway.

At the pipe coupling known, for example, through US-PS 3 983 897, the said projecting portion of the pipe shell is cut off by translatory movement of a valve body in a guide passageway. The said movement is effected in that, for example, a detonation cartridge is detonated by a hammer stroke on a firing pin. This pipe coupling hereby not only has the disadvantage of being complicated, but it also involves a certain risk in connection with the handling of detonation cartridges. The known construction, further, implies certain sealing problems. Summary of the invention

With a pipe coupling according to the present invention it is possible by a simple structural design to provide the feed-pipe in a simple and efficient way with one or more holes for flow connection. to the passageway in the coupling part. The flow area of the holes can be made at least as great as the feed-pipe area. It is further possible that the portion, which was cut-up from the feed-pipe at the making of the hole is retained at the feed-pipe and folded up in the guide passageway of the coupling part, so that said cut-up portion contributes to an efficient locking between the pipe coupling and the feed-pipe. The pipe coupling according to the invention has the further essential advantage, that a complete sealing between the feed-pipe and the branch pipe is obtained when the piston is in the position, in which the connection between said pipes is to be shut off.

The characterizing features of the invention for achieving the aforesaid advantages become apparent from the attached claims.

Brief description of the drawings

The invention is described in greater detail in the following by way of a preferred embodiment and with reference to the accompanying drawings, in which

Fig. 1 is a plane view of a preferred embodiment of a pipe coupling according to the invention connected to a feed-pipe where, however, for better clarity a piston comprised in the pipe coupling is removed, Fig. 2 is a section along the line II-II in Fig, 1, and also here the piston comprised in the pipe coupling is removed,

Fig. 3 is a section along the line III-III in Fig. 1, Fig. 4 is a section corresponding to that shown in Fig. 2, but with the piston inserted in the pipe coupling, Fig. 5 is a plane view corresponding to that shown in Fig. 1 of a second embodiment of a pipe coupling according to the invention, Fig. 6 is a section along the line VI-VI shown in Fig. 5, i.e. a section corresponding to the section III-III in Fig. 1, where the piston comprised in the pipe coupling also is removed, and Fig. 7 is a section corresponding to that shown in Fig. 4, where the piston is inserted in the pipe coupling.

Detailed description of a preferred embodiment

As appears from the embodiment shown in Figs. 1-4, the pipe coupling comprises coupling parts 2a and 2b, which are arranged sealingly about a feed-pipe 1 and by means of, for example, screws 3 are interconnected and embrace said feed-pipe. The coupling further comprises a piston 4 inserted in one coupling part. The sealing between the coupling part 2b and the feed-pipe 1, and also between contacting surfaces of the coupling parts 2a and 2b preferably can be effected by means of a sealing paste.

The coupling part 2b is formed with a guide passageway 5, which in assembled position of the coupling parts is directed perpendicularly to the feed-pipe 1. In said position a portion of the feed-pipe projects into the guide passageway. The coupling part 2b further is provided with a connection 6 for a branch pipe (indicated by dashed lines and designated by 24 in Fig. 1), which connection projects out of the coupling part 2b perpendicularly relative to the guide passageway. The passageway 5 has at its inner end closest to the feed-pipe 1 a widened portion 7, and at its outer end portion outside the connection 6 it is formed with a recess 8.

The outer diameter of the piston 4, which in Fig. 2 is shown outside the coupling part 2b, and in Fig. 4 is shown inserted in the coupling part 2b in an operative position for the pipe coupling, is adapted to the cylindric shape of the guide pass ageway 5. The inner end of the piston in inserted position is formed with a knife 9, and the piston further is provided with a through passageway 10. The piston being in inserted position, it is locked relative to the coupling part 2b by means of a locking ring 11 provided in the recess 8 in the guide passage way 5 and sealed outwardly by means of a sealing ring 12 abutt ing the wall of the guide passageway. In said position the passageway 10 is located on the same level as the connection 6, and the knife 9 is located to the side of the feed-pipe portion projecting into the guide passageway. The knife has a cutting edge 13, which extends from the tip of the knife at least to the shell surface of the feed-pipe which is located farthest inwardly in the guide passageway.

By a pipe coupling according to the embodiment described above, transversely directed pipes easily can be connected without interrupting the operation of pipings transporting liquids or gases. When in the aforesaid assembled position of the pipe coupling the piston 4 is turned clockwise through one revolution, for example by a key handle 14, the knife 9 cuts a hole into the feed pipe 1 in the pipe coupling portion .of.this. The knife 9 and its cutting edge 13 may have different shapes for cutting holes of different shapes. At the embodiment shown, the knife has "plough-shape", and the cutting edge extends aligning with the wall of the passageway 10. By this knife shape two spaced holes 15 with an intermediate bridge 16 are obtained. Besides, the material cut-up from the feed-pipe is not detached, but is folded upward to the widened portion 7 in the guide passageway 5 and retained in said portion as indicated by reference numeral 17. Due to the fact, that the cut-up material does not follow along with the flow and does not disturbe the flow, either, by being folded downward into the same, an effective fixing of the pipe coupling in its position on the feed-pipe is obtained by the folded-up material 17. The piston 4, subsequent to the cutting operation, serves as a valve body for controlling the flow rate through the pipe connection 6. At conventional pipe couplings with valve bodies it has been a problem to achieve fully satisfactory sealing when the flow between feed-pipe and branch pipe was shut off. At the embodiment according to Figs. 1-4, as shown, the problem has been solved by simple means. The piston 4 is provided with a sealing 18, which by a spring washer 19 located inside of the sealing is maintained pressed outward, whereby after the turning of the piston 4 for closing the opening between the connection 6 and passageway 10 the spring-loaded sealing ensures flow shut-off.

In Figs. 5-7 an embodiment is shown where the connection for the branch pipe extends in the same direction as the flow passageway of the piston, which passageway in its turn extends throughout in the same direction as the guide passageway of the coupling part. As appears from the drawings, details corresponding to those at the embodiment shown in Figs. 1-4 have been given the same reference numerals.

At this embodiment a valve body 20 with a through passageway 21 is inserted in the piston 4. The valve body is rotatably adjustable between a position, at which the flow connection between the feed-pipe 1 and the branch pipe 6 through the passageway 21 is fully open, and a position, at which the connection between said pipes is fully closed. Said rotation can be effected, for example, by making a hole 22 through the coupling part for inserting therethrough a screw driver to co-operate with a slit 23 being stationary relative to the valve body 20.

The invention, of course, is not restricted to the embodiments described above and shown in the drawings, but can be varied in several ways within the scope of the attached claims. The pipe coupling, for example, can be designed for the connection of more than one branch pipe, and the knife may be formed to cut, for example, a hole in the feed pipe. The essential feature of the invention is the simple and efficient making of holes in the feed-pipe by turning the knife-carrying piston whereby also large flow holes relative to the dimension of the feed-pipe can be obtained. It also renders possible an efficient locking of the pipe coupling to the feed-pipe by folding-up the material cut-up at the hole making. A further essential property of the invention is the efficient sealing by the spring-loaded gasket when the flow between the feed-pipe and branch pipe is being shut off.

Claims (7)

Claims

1. A pipe coupling for connecting branch pipes to a feed-pipe, comprising coupling parts sealingly embracing the feed-pipe, a cylindric guide passageway in one of the coupling parts, a piston sealingly inserted in the guide passageway and provided.at its inner end with a knife-shaped cutting-up member and formed with a passageway for flow connection between the feed-pipe and the branch pipe connected to the coupling part, so that in assembled position of the coupling parts a portion of the feed-pipe projects in radial direction into the guide passageway, c h a r a c t e r i z e d i n that in said assembled position the knife-shaped member (9) of the piston (4) is located to the side of said inward projecting portion of the feed-pipe (1), and the cutting edge (13) of the knife-shaped member extends from its tip at least to the same level as the shell surface of said feed-pipe portion located farthest inwardly in the guide passageway (5), and that upon rotation of the piston (4) in this position said knife-shaped member (8) cuts up at least one hole (15) in the feed-pipe (1).

2. A pipe coupling as defined in claim 1, c h a r a c t e r i z e d i n that the material (17) cut up of the feed-pipe (1) is folded up inward in the guide passageway (5) owing to the design of the knife-shaped member (9).

3. A pipe coupling as defined in claim 2, c h a r a c t e r i z e d i n that the folded-up material (17) is fit in a recess (7) in the guide passageway (5).

4. A pipe coupling as defined in any one of the preceding claims, c h a r a c t e r i z e d i n that the knife-shaped cutting-up member (9) is formed so ag upon rotation of the piston (4) to-cut up two holes (15) in spaced relationship along the feed-pipe (1).

5. A pipe coupling as defined in any one of the preceding claims, c h a r a c t e r i z e d i n that the piston (4) with its flow passageway (10) acts as a valve means.

6. A pipe coupling as defined in claim 5, c h a r a c t e ri z e d i n that the piston (4) is provided with a sealing

(16), which is resilient outward to the wall of the guide passageway (5) and upon rotation of the piston to fully closed valve covers the opening of the flow passageway (10) to the branch pipe.

7. A pipe coupling as defined in any one of the claims 1 - 4, c h a r a c t e r i z e d i n that the piston (4) is inserted in a valve body (20) with through passageway (21), which valve body (20) is rotatable between a position, in which the flow passageway (10) of the piston is closed, and a position, in which the flow connection between the feed-pipe (1) and the branch pipe (24) is established through the passageway (21) of the valve body.