Apparatus for welding articles of thermoplasts

Claim 1

In an apparatus for welding thermoplastic articles with additional welding material comprising a welding head including feeding means for feeding a rod of welding material through the head, a melting housing for the welding materials mounted on said welding head and receiving said welding material therefrom, and a welding shoe mounted on the melting housing and having an outlet opening formed therein for receiving and discharging plasticized welding material from the welding housing, said shoe including a smoothing element, a guide element for guiding the apparatus along a point to be welded, and heating means for heating the joint to be welded, the improvement comprising said melting housing having a guide channel, a melting channel, a melting chamber and a collecting chamber formed therein, said melting channel being located to receive said welding material from said feeding means and for preheating the welding material, said melting channel communicating at one end with said guide channel and having a diminishing cross-sectional area and being closed at its other end, said melting channel being in communication with said melting chamber to discharge welding material heated in the melting channel into said melting chamber, said melting chamber being located in communication with said collecting chamber which is in communication with said outlet opening of the welding shoe, and heating means in said housing for heating welding material in said melting channel and melting chamber.