Following the plastic parts to be melted, to get them in one piece is called fusion welding. For said melting process aluminium plates coated with Teflon or brass wires are used. The welding process carried out by transferring a current from a wire is called electrofusion welding. The purpose of the wire is to cause the plastic to be melted and to create a pressure by dilating, forming a resistance and transferring the heat occurred when the current is transferred to the plastic. Plastic molecules combine under high heat and pressure and the welding structure is formed.

The invention, especially relates to the mounting the male (spigot) and female (muff) tips of the corrugated pipes, which are made from plastic based material by using electrofusion welding method and, peculiarly, where the copper wires were used to melt the regions to be combined, to each other.

STATE OF THE ART Corrugated pipes made from plastic material are generally used in waste water systems such as for sewer systems and rain water and they are manufactured generally from PP and HDPE materials because of their advantageous effects such as raw material access, cost convenience and mechanical and chemical behaviour stability.

Most widely used combining methods among the approaches in present art for combining plastic based pipes are gasket muff combining and built in gasket muff combining methods.

In gasket muff combining method, plastic based corrugated pipes, which enters from the openings on the both side of the female part, which is also called muff, are mechanically connected by means of the gaskets supplied to the inside of the rib slots built in the outer circumferential surfaces of said pipes, in order to ensure the sealing.

Greatest disadvantage comprised by the gasket muff combining is that the muff is included in the combining process for corrugated pipes following that it is produced in an independent process as a combining element. This results the usage of another production part, which affects both the process speed and the costs adversely. Drawings corresponding to this present state of the art are shown in the section of drawings with the reference"Figure 1".

Other present application, namely built in gasket combining method, the tip part of the corrugated pipe to be combined to the muff, which is manufactured with the pipe in an integrated way, is supplied (so as that it may function as the male part).

In this method, a gasket is positioned in the rib slat that was structured along the perimeter of the corrugated pipe and thus, a mechanic connection is formed in order to ensure the sealing.

Greatest disadvantage comprised by the built in gasket muff combining is that the leaking problem due to the constructive structure of the integrated muff can not be removed. The reason of that the sealing can not be ensured completely is to force the materials originally having different characteristics to work in a system.

In addition, in both methods, repair and replacement costs are reaching to quite high levels in terms of both workmanship and material factors because that the gasket becomes deformed through long run usage times and hence it losses its functionality. Drawings corresponding to this present state of the art are shown in the section of drawings with the reference"Figure 2".

OBJECTIVES OF THE INVENTION The object of the present invention is to combine the corrugated type pipes made from plastic materials by using electrofusion method and enhancing the sealing function.

Another object of the invention is to combine the corrugated type pipes made from plastic materials by using electrofusion method and to extend the lifespan of homogenous mechanical connection and connection points.

Another object of the invention is to combine the corrugated type pipes made from plastic materials by using electrofusion method and to provide a decrease in manufacture costs.

The present invention is a corrugated pipe, which is to be combined by electrofusion method, comprising a spigot part/male part (2) made from plastic based material and a muff parUfemale part (1) and a rib formation (5), which is circumferentially embodied along the outer surface of the body (4) region located between the said spigot part (2) and said muff part (1) and which is composed of indent/rib slot (6) and juts, characterized in that, the spigot part (2) and the muff part (1) entering into the spigot part (2), the melting means (9), ensuring electrofusion, is supplied therebetween, comprise a predetermined rate of conical shape.

The conductive wires, which ensure the combination of the plastic based corrugated pipes by the electrofusion method within the scope of the present invention, preferably comprise a high rate of copper element by weight.

The alteration of the resistance of the copper material by temperature is that the resistance increases by temperature. Plastic materials conduct less heat per unit time by increase in their temperature. As soon as the electricity is given to the wire and pipe system, which are cool in the initial phase of the welding process, the copper wire heats and begin to melt the surrounding plastic, the heat flow transferring through the melting plastic begins to cool in connection to that and the wire works to increase the surface temperature. However, due to the increase in

the resistance of the wire, the heat flow produced by it begins to decrease.

Consequently, the heat need of the plastic decreases and the wire ensures the convenient working of such dual by giving less heat. Characteristic of the plastic materials may be controlled during the welding process in this way.

DESCRIPTION OF THE DRAWINGS In order to understand the configuration of the present invention and advantages thereof together with additional elements in best way, it must be evaluated along with the figures described below.

Figure 1 is a representative application drawing of the gasket muff corrugated pipe combination that depicts the state of the art.

Figure 2 is a representative application drawing of the built in gasket muff corrugated pipe combination of the invention, which depicts the state of the art.

Figure 3a is a representative application drawing of the corrugated pipe made from plastic based material of the invention.

Figure 3b is a representative application drawing of the combination condition of the corrugated pipes made from plastic based material of the invention.

Figure 4a is a representative application drawing of the alternative corrugated pipe made from plastic based material of the invention.

Figure 4a is a representative application drawing of the combination condition of the alternative corrugated pipe made from plastic based material of the invention.

REFERENCE NUMBERS OF THE PARTS IN THE FIGURES Muff part-female part 2 Spigot part-male part 3 Muff rib 4 Body 5 Rib 6 Rib slot

7 Internal tension apparatus 8 External compression apparatus 9 Wire 10 Spigot internal surface 11 Muff internal surface DETAILED DESCRIPTION OF THE INVENTION Figure 1 and Figure 2 are representative illustrations of the previous art and shall not be considered in this section.

In Figure 3a, the vision of the corrugated pipe made from plastic based material within the scope of the invention is given. According to the figure, tip parts of the pipe comprise a female part-muff part- (1) and a male part-spigot part (2).

Outer surface of the body (4) of the corrugated pipe which is located between said tip parts (1.2) consists of a rib (5) composed of a certain amount of indents and juts. Indents of such rib (5) are called rib slot (6) and the dimension of depth is in certain values which are determined before as desired.

In the preferred configuration of the invention, a muff rib (3) is configured at a region of the muff essentially towards to its tip part. Such muff rib (3) is a result of the manufacture process of the corrugated pipe and, if desired, the number of the muff ribs may be two, three or more.

Either muff part or the spigot part, that is the internal surface of the muff part (11) and the external surface of the spigot part (10), comprise a predetermined amount of conical shape throughout all such parts or along a certain distance of such parts.

In Figure 3b, it is given the vision of the corrugated pipes made from plastic based material during combination by electrofusion method. For the combination process, the pipes are firstly taken in a dike or another region where the pipe may be installed, and then, the wires (9), through which the electricity current shall be transferred, are supplied on the conical external surface of the spigot part (10), which shall enter into the conical internal surface of the muff part (11).

In the following stage, the spigot part (2) of the primary pipe is mounted in the muff part (1) of the secondary pipe by centralizing. In this stage, a care shall be laid on that the wires that provide electrofusion might not be exposed.

In order to prevent the dilation of the pipes connected into each other during the combination process by electrofusion welding, apparatuses that prevent the dilation shall be positioned on the welding region, namely muff part (1) and on the spigot part (2) which enters into the muff part (1). Especially, an external compression apparatus (6) shall be supplied on the external surface of the muff part (1) and an internal tension apparatus (7) shall be supplied on the internal surface of the spigot part (2) respectively, hence a suitable pressure force shall be provided.

In order to initiate the welding process, depending on the dimensions of the diameters of the pipes to be combined, a predetermined amount of current is given to the wires, (+) and (-) tips of which are exposed on the external part of the connection and in this way the welding process for the plastic based corrugated pipes by electrofusion is carried out. In the later stage, pipes are left for cooling.

The conductive wires, which are used in the combination of the corrugated pipes made from plastic based material by the electrofusion method within the scope of the present invention, are copper based but other wires such as from brass etc. may be used during the pipe connection procedure.

According to the alternative corrugated pipe in Figure 4a, whole of the external surface (10) of the spigot part (2) is not structurally in a conical formation but only its part, which comprises the flesh thickness, is structured in a conical form.

Although this is not shown in the figure, a similar formation may apply to the muff part (1) also. That is, it is possible that, only the flesh thickness between the internal surface (11) and external surface of the muff part (1) has a conical form.

If Figure 4b, it is given the vision of such alternative corrugated pipe during combination according to the scope of the present invention. In this alternative, before the electrofusion process initiated, it is provided that the spigot (2) is

entered into the muff (1) until the first rib, where the spigot part (2) is finished and the series of rib (5) began.

In the scope of present invention, conical angles of the muff part (1), spigot part (2) or spigot external surface (10) and/or the muff internal surface (11) of the plastic based pipes to be combined by electrofusion are preferably between 1°-10° and more preferable ranges between 2°-4°. However all conical values must be considered within the scope of present invention.

According to an alternative configuration in the scope of the invention, in order to combine the pipes by electrofusion, an instable independent welding brace in the pipe may be used as an interval layer. Such independent welding brace may be used by locating it on the rib (5) or into the rib slot (6). In this alternative, a welding brace is formed by coiling the copper wires on a separate plate, preferably HDPE plate, having the form of a strip. Such welding brace may be used later by locating it externally on the rib or into the rib slot.

According to another alternative in the scope of the present invention, besides the combination of corrugated pipes made from plastic based material, other pipes are also combined where the electrofusion method and copper based wires as conductive wire are used. In this alternative also, the muff part (1) of the plastic based pipes and the spigot parts (2) comprise a conical form in predetermined values.