Background Art To connect synthetic resin tubes, both ends of the synthetic resin tube are inserted into an electrofusion socket and then electric power is supplied to the electrofusion socket such that the synthetic resin tubes can be fused on the electrofusion socket.

Fig. 1 illustrates a process for connecting synthetic resin tubes to an electrofusion socket function.

To connect general synthetic resins 1 and 2 with each other, the synthetic resins 1 and 2 are inserted into a cylindrical electrofusion socket 10. One ends of adaptors 24 and 26 fitted to plug insertion pins 15 and 15'are inserted into electric terminals 11 and 12 of the electrofusion socket 10 respectively and the other ends of the adaptors 24 and 26 are inserted into plugs 21 and 22 respectively such that electric power is supplied. The electrofusion socket 10 has heating wires 13 and 14 that are arranged on inner circumference surface thereof and contact the electric terminals 11 and 12 respectively. When the plugs 21 and 22 are connected to the electric terminals 11 and 12 respectively and electric power is supplied to the electric terminals 11 and 12, the heating wires 13 and 14 are heated and the synthetic resin and the synthetic resin tubes surrounded by the heating wires 13 and 14 are fused onto the electrofusion socket 10.

Here, the electric terminals 11 and 12 has respectively plug acceptors 16 and 16'that are cylindrical with a predetermined thickness such that the ends of the adaptors 24 and 26 can be inserted into the electric terminals 11 and 12 respectively. The plug acceptors 16 and 16'have insertion pins 15 and 15'projecting at the centers thereof respectively. The

projecting insertion pins 15 and 15'can be inserted into center concave portions of the adaptors 24 and 26 respectively. The plugs 21 and 22 are formed on the ends of two electric lines respectively. Fixers 23 and 25 are formed on the ends of the plugs 21 and 22.

The adaptors 24 and 26 are inserted into and fixed in the fixers 23 and 25 respectively. The adaptors 24 and 26 can be coupled with and removed from the fixers 23 and 25. The adaptors 24 and 26 have center concave portions at a center of the bottom thereof. The sidewalls of the center concave portions are provided with metal portions to electrically contact the insertion pins 15 and 15'.

When the synthetic resin tubes are connected to each other using the electrofusion socket 10, a worker measures the size of the insertion pin 15 and 15'and the inner diameter of the plug acceptors 16 and 16', prepares the adaptors fitted to the inner diameter of the plug acceptors 16 and 16'and couples the adaptors 24 and 26 with the fixers 23 and 25 respectively to finish the preparation process.

Here, the diameter of the insertion pins 15 and 15'is regulated to be 4.7 mm, 4.0 mm, 2.9 mm and 2, 2 mm. The worker should prepare all the adaptors 24 and 24'according to the diameters of the insertion 15 and 15', and should remove and install the adaptors 24 and 24'whenever the diameters of the insertion 15 and 15'are different.

Since the adaptors 24 and 26 can be coupled with and removed from the fixers 23 and 25, electric arc or heat is caused when the adaptors 24 and 26 incompletely contact the fixers 23 and 25, so that fire accident may happen and the lifetime of the machine may be reduced.

Disclosure of the Invention An object of the present invention is to provide a power supplier for supplying electric power to electrodes of an electrofusion socket to allow a worker to select a plug fitted to an adaptor in size thereof without changing the adaptors by providing the power supplier with a plurality of plugs whose diameters are different from each other.

Another object of the invention is to provide a power supplier for supplying electric power to electrodes of an electrofusion socket to get rid of a removable portion of a plug to prevent the plug from being heated or the electric arc from occurring at the plug when electric power is supplied.

Brief Description of the Drawings The above object, other features and advantages of the present invention will become more apparent by describing the preferred embodiment thereof with reference to the accompanying drawings, in which: Fig. 1 illustrates a process for connecting synthetic resin tubes to an electrofusion socket; Fig. 2 is a perspective view showing an embodiment of the present invention; and Fig. 3 is a perspective view showing that an embodiment of the present invention is adapted to an electrofusion socket.

Best Mode for Carrying Out the Invention To achieve the above objects of the present invention, there is provided a power supplier for an electrofusion socket having electrodes comprised of a pair of insertion pins and being used for connecting two synthetic resin tubes, the power supplier comprising : two power lines for supplying an electric power; and plug sections each having one or more plugs whose insertion holes into which insertion pins inserted are different in diameter, the plugs being respectively installed at ends of the power lines.

Preferably, the plug sections comprise two plug sections, and the two plug sections comprise a pair of plugs whose corresponding diameters are identical to each other.

The plug may comprise a cylindrical insertion hole into which the insertion pin is inserted at a longitudinal end surface thereof, the insertion hole has a conductor connected to the power line, and the insertion pin is inserted into the insertion hole such that the electric power is supplied to the electrofusion socket through the power lines.

Fig. 2 is a perspective view showing an embodiment of the present invention. Fig.

3 is a perspective view showing that an embodiment of the present invention is adapted to an electrofusion socket.

Plug sections 100'and 200'are formed on the ends of power lines 100 and 200.

The plug sections 100'and 200'consists of extensions 105 and 205 extended from the ends of the power lines 100 and 200, and plugs 101,102, 103,104, 201,202, 203 and 204 projecting from the extensions 105 and 205 to both sides of the extensions 105 and 205.

Cylindrical insertion holes into which the insertion pins 15 and 15'are inserted are formed at a longitudinal end surface of the electrofusion socket 10. The sidewalls of the concave portions are provided with metal conductors to electrically contact the insertion pins 15 and 15'such that the electric power is supplied to the insertion pins 15 and 15'through the power lines 100 and 200. Here, the diameters of the insertion holes of the plugs 101 and 201, the diameters of the plugs 102 and 202, the diameters of the plugs 103 and 203, and the diameters of the plugs 104 and 204 are 4.7 mm, 4.0 mm, 2.9 mm and 2.2 mm, respectively.

Thus, the plug sections 100'and 200'have corresponding plugs whose insertion holes are identical in diameter at corresponding positions such that the plugs of the plug sections having an identical diameter are inserted onto the two insertion pins 15 and 15'as shown in FIG. 3.

Industrial Applicability According to the present invention as described above, unlike the conventional adaptor which is detachably coupled, the plug is directly inserted onto the insertion pin such that the plug is not heated and the electric arc does not occur. Accordingly, the power consumption is small and fire accidents can be reduced. Since the plugs have insertion holes of different diameters into which insertion pins having different diameters can be inserted, a worker can work conveniently and feels easy to work.