WO2003058108A1

WO2003058108A1 - Connector for connection of metal pipes and relative pipe connecting system

Info

Publication number: WO2003058108A1
Application number: PCT/EP2002/014466
Authority: WO
Inventors: Claudio Castiglioni; Alessandro Costanzi
Original assignee: INDUSTRIE METALLURGICHE SPOLETO SpA
Current assignee: INDUSTRIE METALLURGICHE SPOLETO SpA
Priority date: 2002-01-10
Filing date: 2002-12-18
Publication date: 2003-07-17
Anticipated expiration: 2004-07-10
Also published as: EP1463900A1; ITMI20020013U1; BR0207874A; CN1612988A; ITMI20020013V0; AU2002358747A1

Abstract

A female connector (1; 101; 201) for connecting at least two stiff metal pipes (2) and a piping system obtained with the use of said female connector are described. The female connector is made of cast iron by smelting or casting and is coupled to the ends of metal pipes (2) by means of pressing with automatic pressing pliers.

Description

CONNECTOR FOR CONNECTION OF METAL PIPES AND RELATIVE PIPE CONNECTING SYSTEM

DESCRIPTION

The present invention refers to a connector for connecting metal pipes and a relative pipe connecting system.

As is known, in the building industry, piping systems are used for the distribution of fluids, such as water, gas and the like. Said piping systems comprise a plurality of stiff metal pipes, generally made of iron, which are joined to each other by means of threaded female connectors, generally made of cast iron. To make the join between a pipe and a connector, an outside thread must be made at the end of the pipe, then the connector is screwed onto the pipe so that the inside thread of the connector engages with the outside thread of the pipe.

Said pipe connecting system, according to the prior art, has various drawbacks.

In fact a threading die able to create a thread on the pipes must be used at the work site. Said threading die is extremely bulky and difficult to transport.

Once the thread has been made on the pipe, the threads must be wound with hemp or Teflon to ensure the tightness of the coupling with the connector. This involves a further waste of time and material.

Lastly screwing of the elements to be joined must be done with great professionalism, to ensure a perfect seal and compliance with the overall dimensions.

As a result the pipe connecting system according to the prior art involves very long working times which affect the final cost of the work.

The object of the present invention is to overcome the drawbacks of the prior art by providing a pipe connecting system that is practical for the operator and is able to minimize work times. Another object of the present invention is to provide such a system for connecting pipes that is versatile, flexible and suitable to be applied to pipes of various shapes and dimensions.

Yet another object of the present invention is to provide such a pipe connecting system that is economical and simple to make.

These objects are achieved in accordance with the invention with the characteristics listed in appended independent claim 1.

Advantageous embodiments of the invention are apparent from the dependent claims.

The pipe connecting system provides for the use of a female connector to connect at least two stiff metal pipes to each other. Said female connector is made of cast iron by smelting or casting or pouring and is coupled to the ends of the metal pipes by pressing, by means of pressing pliers. Seals such as O-rings to ensure tightness are advantageously housed inside the female connector.

The advantages of the female connector according to the invention are evident. In fact in such a connector the thread is eliminated and tightness is ensured by the O-rings.

Furthermore the pressing pliers are a compact and manageable tool.

In this manner the pipe connecting operations are simplified and working costs and times are reduced.

A cast iron with a carbon content of about 2.1% is preferably used in order to have greater pourability than that of steel and obtain a material that lends itself to making small castings with a complex shape, such as connectors.

Furthermore the cast iron connector is subjected to careful heat treatment, to acquire a comparable toughness and ductility to that of steel, thus proving ideal to be pressed with the pressing pliers.

Further characteristics of the invention will be made clearer by the detailed description that follows, referring to purely exemplary and therefore non-limiting embodiments thereof, illustrated in the appended drawings, in which: Figure 1 is an exploded perspective view, illustrating a first embodiment of the pipe connecting system according to the invention, wherein an assembly comprising a linear connector and two pipe ends to be connected is shown;

Figure 2 is an axial sectional view of the assembly of Figure 1 assembled;

Figure 3 is an axial sectional view of the linear connector;

Fig. 4 is a perspective view according to a second embodiment of the invention, wherein an L-shaped connector that connects two pipe ends is shown;

Figure 5 is an axial sectional view of the L-shaped connector of Figure 4;

Figure 6 is a perspective view according to a third embodiment of the invention, wherein a T-shaped connector which connects three pipe ends is shown;

Figure 7 is an axial sectional view of the T-shaped connector of Figure 6.

The pipe connecting system according to the invention is described with the aid of the figures.

A first embodiment of the invention is described with reference to Figures 1-3.

Figure 1 shows a linear connector able to connect the ends of two pipes 2. The linear connector 1 has a substantially cylindrical body 10, hollow on the inside so as to define a cylindrical axial passageway 11 open at the front and rear.

The linear connector 1 has an inside diameter substantially equal to or slightly smaller than the outside diameter of the pipes 2, so that the coupling between the connector 1 and the pipes 2 can have a minimum clearance.

As also shown in Figures 2 and 3, two pairs of annular seats 12, able to receive the respective O-rings 13, are provided in the inside surface of the connector 1, near the two ends. The O-rings 13 are made of rubber and serve to ensure a good seal against the outer surface of the pipes 2. Again in the inner surface of the connector 1 , near the central position, an annular collar 14 which protrudes radially inwards defining two abutment surfaces is provided. The annular collar 14 serves as a stop for insertion of the pipes 2.

The connector 1 has at its ends two cylindrical tangs 15 with a greater outside diameter with respect to the central part of the body 10. The cylindrical end tangs 15 serve to make the thickness of the connector 1 uniform in the area wherein the seats 12 of the O-rings 13 are provided.

For assembly of said piping system according to the first embodiment of the invention, it is sufficient to insert the ends of the two pipes 2 into the respective mouthpieces of the connector 1, until the ends of the two pipes 2 abut against the collar 14 of the connector 1. At this point, the connector 1 is pressed by means of automatic pressing pliers, pressing it onto the outer surface of the pipe 2, so as to fix it firmly to the pipe 2. The O- rings 13 also are pressed into their seats 12, ensuring a good pneumatic seal.

Hereunder, like or corresponding elements to those described will be indicated with the same reference numerals and description thereof will be omitted.

Figures 4 and 5 show a connector 101 according to a second embodiment of the invention. The body 10 of the connector 101 is bent in an elbow and is substantially L- shaped to join two pipes 2 with an angle of 90° between them. In this case two annular stop collars 14 each disposed at the ends of the curved portion of body 10 are provided.

Figures 6 and 7 show a connector 201 according to a third embodiment of the invention, wherein the connector 201 is a three-way connector to connect three pipes 2.

The body 10 of the connector 201 is substantially T-shaped with three entry mouthpieces for three pipes 2. As a result, two pipes are connected along a straight line and the third pipe is connected with an angular distance of 90° between the first two. In this case, three annular stop collars 14 are provided, disposed in such positions as to prevent the ends of the pipes inserted into the connector 201 from interfering with each other. Clearly other types of connector can be provided, such as for example cross-shaped connectors to connect four pipes spaced with angle of 90° between them or curved, parabolic connectors, and the like to connect pipes that follow complex curving courses.

The peculiarity of the invention is represented by the fact that said connectors are made of cast iron and coupled to the metal pipes by means of pressing. A cast iron with a carbon content of about 2.1% is preferably used to have good pouring characteristics. Thus the connector is obtained through smelting and casting or pouring of cast iron. Subsequently the connector is subjected to heat treatment to obtain good characteristics of toughness and ductility.

Numerous variations and changes of detail within the reach of a person skilled in the art can be made to the present embodiments of the invention, without thereby departing from the scope of the invention as set forth in the appended claims.

Claims

1. A female connector (1 ; 101 ; 201) for joining at least two stiff metal pipes (2) characterised in that it is made of cast iron and is coupled to the ends of the metal pipes (2) by means of pressing.

2. A female connector according to claim 1, characterised in that it comprises sealing means (13) disposed in the inside surface thereof to exert a seal with the outside surface of said pipes (2).

3. A female connector according to claim 2, characterised in that said sealing means (13) comprise a pair of O-rings disposed in annular seats (12) formed in the inner surface of said connector, near each of the mouthpiece ends of the connector.

4. A female connector according to any one of the preceding claims, characterised in that on the outside surface of said connector, near the ends, cylindrical parts (15) with a greater outside diameter than the body (10) of the connector are formed.

5. A female connector according to any one of the preceding claims, characterised in that it comprises at least one annular collar (14) protruding inward from the inside surface of the connector, to generate a stop abutment surface for the end of the pipes (2) to be connected.

6. A female connector according to any one of the preceding claims, characterised in that it has a linear shape to connect two pipes (2) along a straight line.

7. A female connector (101) according to any one of claims 1 to 5, characterised in that it is substantially L-shaped to connect two pipes (2) with an angular distance of 90° between them.

8. A female connector (201) according to any one of claims 1 to 5, characterised in that it is substantially T-shaped to connect three pipes (2), whereof two pipes along a straight line and the third pipe with an angular distance of 90° between the first two.

9. A female connector according to any one of claims 1 to 6, characterised in that it is substantially cross-shaped to connect four pipes with an angular distance of 90° between them.

10. A female connector according to any one of the preceding claims, characterised in that the cast iron used has a carbon content of about 2.1%o.

11. A female connector according to any one of the preceding claims, characterised in that it is made by smelting, pouring or casting of iron.

12. A female connector according to any one of the preceding claims, characterised in that is subjected to heat treatment to improve its toughness and ductility.

13. A female connector according to any one of the preceding claims, characterised in that it is coupled to the ends of metal pipes (2) by means of automatic pressing pliers.

14. A connecting system for pipes comprising a plurality of stiff metal pipes (2), connected to each other by means of connectors, characterised in that it comprises at least one female connector (1; 101; 201) according to any one of the preceding claims, made of cast iron and coupled to the ends of the metal pipes by means of pressing.

15. A pipe connecting system according to claim 14, characterised in that said stiff metal pipes (2) are made of iron.