Georg Fischer Rohrleitungssysteme Ag

Georg Fischer Aktiengesellschaft

Jorg Wermelinger

Ernst Tanner

Peter Haug

Peter Kunz

Theo Gassner

Marcus Bayer

Heinz Hunger

Richard Stehle

A clamping device for fixing plastic molded parts during welding is proposed, comprising a flange-like fastening part for fastening on a plastics welding device, the fastening part having at least one first annular recess for receiving a clamping element and the fastening part having at least one second recess for receiving spring elements acting radially on the clamping element, the clamping element having at least one projection on an inner surface which is arranged opposite the outer surface of the plastic molded part. The clamping element allows good fixing of the plastic molded parts in a very confined space.

Clamping element

The invention proposes an apparatus an a method of welding together articles made of a termoplastic material by means of a butt welding method. The articles are held in coaxial relationship by means of a pair of clamping mechanisms. A heating element can be brought between the two articles to heat up their respective facing front faces, whereafter the heating element is removed and the heated front faces brought into mutual contact. For determining the strength of the welding zone, the ambient temperature is considered. For this purpose, a thermal sensor is provided that is arranged at the welding apparatus. The thermal sensor is thermally insulated against the welding apparatus.

Apparatus for butt welding of articles made of thermoplastic material

The invention provides a method of welding together articles made of a thermoplastic plastic material by means of a butt welding process, whereby the two articles to be welded together are held in place in coaxial relationship by means of clamping devices. Then, the two articles are heated up by means of a heating device that can be placed between the two articles to create a molten up welding zone in the region of each of the free ends of the two articles. As soon as the welding zone has reached the proper temperature, the two articles to be welded together are pressed together to create a bulge. Finally, the temperature of that bulge is continuously monitored and the temperature of the material in the interior of the afore mentioned welding zone is calculated according to the formula ##EQU1## until such a temperature is reached at which the articles can be removed from the clamping devices.

Method of monitoring the bulge temperature when welding plastic

A method for welding tubular thermoplastic parts includes the steps of (a) providing first tubular and second tubular parts made of thermoplastic material and each having an end face; (b) determining a desired butt weld length for the parts; (c) providing a clamping member for coaxially clamping the parts, the clamping member including a first clamp for clamping the first part and a second clamp for clamping the second part, at least one of the first clamp and the second clamp being axially displaceable relative to the other between a part loading position and a butt weld position; (d) adjusting the butt weld position of the first and second clamps to a final butt weld position corresponding to the desired butt weld length; (e) clamping the parts in the clamps when the clamps are in the part loading position; (f) positioning a cutter between the end faces of the parts; (g) displacing the at least one of the first and second clamps toward the final butt weld position so that the cutter machines the end faces of the parts so as to provide machined end faces which are spaced to provide the desired butt weld length; (h) positioning a heater between the machined end faces of the parts so as to heat the machined end faces to a welding temperature; and (i) displacing the clamps toward the final butt weld position so that the machined end faces of the parts contact each other prior to the final butt weld position and are further pressed together to the final butt weld position.

Method for welding tubular parts

A method of manufacturing by welding a shaped workpiece, which is formed of a plastic material and which consists of a tubular part having a radial bore and a union weldable to the tubular part in a region of the radial bore, includes bringing an end face surface of the union into abutting engagement with an outer circumference of the tubular part in the region of the radial bore, and heating a circular region around the radial bore of the tubular part and the end face surface of the union by heat radiation, with subsequent pressing the two parts against each other. The apparatus for implementing the method includes first and second clamping devices for supporting the union and the tubular part, respectively, with the second clamping device having a support member having a shape corresponding to an inner profile of the tubular part, and a pin supported in the support member for displacement in a direction transverse to a longitudinal axis of the support member, and a heating device for heating the two parts.

Apparatus for welding shaped workpieces formed from a plastic material

A method of manufacturing by welding a shaped workpiece, which is formed of a plastic material and which consists of a tubular part having a radial bore and a union weldable to the tubular part in a region of the radial bore, includes bringing an end face surface of the union into abutting engagement with an outer circumference of the tubular part in the region of the radial bore, and heating a circular region around the radial bore of the tubular part and the end face surface of the union by heat radiation, with subsequent pressing of the two parts against each other. The apparatus for implementing the method includes first and second clamping devices for supporting the union and the tubular part, respectively, with the second clamping device having a support member having a shape corresponding to an inner profile of the tubular part, and a pin supported in the support member for displacement in a direction transverse to a longitudinal axis of the support member, and a heating device for heating the two parts.

Method of and apparatus for manufacturing of shaped workpieces formed

An apparatus for end face welding of plastic parts that includes two spaces clamping devices for retaining the plastic parts, a heating device movable into an operative position between the clamping devices, and a stop element for retaining the heating device in its operating position, and in which the stop element is automatically disengaged from the heating device upon a return movement of a carriage supporting one of the clamping devices after heating of the ends of the parts to enable automatic return of the heating device to its initial position.

Apparatus for end face welding of plastic parts

An arrangement for butt-welding tubular plastic components includes two chucking devices for holding the components in coaxial positions relative to each other and a heating device for heating the ends of the components without contact. The heating device includes a heating element which can be swung between the two chucking devices. The heating element heats the ends of the components without contact by heat rays. The heating element includes a metal plate which is coated with a ceramic coating and which is electrically heatable by heating cartridges.

Arrangement for butt-welding plastic material components

A method of connecting pipes of plastics material of a double pipe system and a pipe connection made by the method. The inner pipes of the pipe system are connected to each other with a sleeve member by welding or gluing. Clamping jaws are used for holding and moving the inner pipes toward each other. The outer pipes are shorter than the inner pipes at least by the thickness of the two clamping jaws. For bridging the gap between the outer pipes, an expandable intermediate ring is inserted in the gap. An electric welding sleeve is used for connecting the outer pipes and the intermediate ring.

Method of connecting pipes of plastics material of a double pipe system

A double-walled pipeline system for flow media with an inner pipeline conduit including fittings, such as, T-pieces, angles, or bends, and instruments, such as, valves, stopcocks, etc., and with an outer pipeline conduit arranged concentrically to the inner pipeline conduit. The outer pipeline conduit includes two-part fittings and instrument casings, so that continuously connected outer annular space is formed in the pipeline system.

Double-walled pipeline system

A pipe connecting member of plastics material for pressurized fluid lines. The pipe connecting member has sleeve portions and a middle portion extending between and connecting the sleeve portions. The sleeve portions receive in a tightly sealed manner the pipes to be connected. The middle portion has an outer surface which is circular in cross-section. The middle portion has a wall thickness which changes continuously in circumferential direction and an inner surface with two inner surface area portions which extend eccentrically relative to the outer surface of the middle portion. The middle portion has the greatest wall thickness where it intersects the plane extending through the sleeve axes.

Growing community of inventors

Schaffhausen, Switzerland

Jorg Wermelinger