Abstract: A method and an apparatus for manufacturing window frames from plastic sections, wherein the plastic sections for always two window frames to be welded at a distance one above the other are placed in the double welding heads of a horizontal four-head welding machine, and wherein the double welding heads are arranged in pairs on a displaceable carriage so as to be shiftable relative to each other. The plastic sections are then clamped in the welding machine and are welded. After at least partial cooling, the welded window frames are released and removed. At least two support elements arranged at a short distance from one carriage and directed toward the other carriage are moved from two opposite sides underneath two welded window frames.

Abstract: The present invention relates to a method and an apparatus for manufacturing rectangular frames of plastic material, for example, casements and door and window frames. The frames are manufactured in a vertically operating or essentially vertically operating welding machine which is equipped with four welding heads which are movable relative to each other. Four plastic sections which are cut to length at the end faces and with bevels are placed from the operator side with the use of welding pieces into the at least one welding machine. The plastic sections are then clamped in the welding machine. All miter surfaces are then simultaneously heated and joined together under pressure and the formation of welding beads to produce a closed frame. After moving the welding heads apart, the frame is subsequently moved out of the clamping plane on the side of the welding machine facing away from the operator side and is transferred to a transport device.

Abstract: The present invention relates to a method and an apparatus for manufacturing rectangular frames of plastic material, for example, casements and door and window frames. The frames are manufactured in a vertically operating or essentially vertically operating welding machine which is equipped with four welding heads which are movable relative to each other. Four plastic sections which are cut to length at the end faces and with bevels are placed from the operator side with the use of welding pieces into the at least one welding machine. The plastic sections are then clamped in the welding machine. All mitre surfaces are then simultaneously heated and joined together under pressure and the formation of welding beads to produce a closed frame. After moving the welding heads apart, the frame is subsequently moved out of the clamping plane on the side of the welding machine facing away from the operator side and is transferred to a transport device.

Abstract: A method of manufacturing rectangular frames made of plastic materials, in which at least two four-head welding machines arranged on a turntable are alternatively fitted out with four plastic shaped pieces cut to a predetermined length with corresponding mitres, and clamped together. A frame is welded in a respective welding machine by applying heat and pressure to all mitre surfaces to form welding beads thereat. The welded frame is then transferred to a cleaning machine for treatment of protruding weld bead portions.