METALLENE BOHRLOCHSIEBZUSAMMENSETZUNG MIT ENDSTUECK AUS PLASTIK UND VERFAHREN, DIESE ANZUBRINGEN.

摘要

The invention relates to conventional metal well screens which have a screen wire (30) wrapped about a plurality of internal rods (32) to define the screen slots (34), and particularly to a novel plastic end fitting (10) made of a thermoplastics material which is mechanically attached to the well screen by means of a plurality of circumferentially spaced tongues (18) which engage the inside surface (30 min ) of the screen wires and have a portion (18 min ) of their outer surface positioned within the screen slots. Slots (20) formed in the end fitting between the tongue portions contain the support rods (32). A method of attaching a thermoplastics fitting made of a material such as polypropylene is also disclosed and includes the steps of heating the tongue portions (18) so that a portion of their outer surface (18 min ) is melted and then is forced radially outwardly into the screen slots, and preferably slightly beyond them (18 sec ), by a pressure applying device such as a tapered wedge tooling arrangement (42, 44). Induction heating (38) of the screen wires can indirectly heat the thermoplastics material by conduction. However, the fitting attachment procedure may be speeded up by preheating the fitting.