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1. (US4334146) Method and apparatus for joining thermoplastic line elements

Office : United States of America
Application Number: 06177760 Application Date: 28.12.1979
Publication Number: 4334146 Publication Date: 08.06.1982
Grant Number: 4334146 Grant Date: 08.06.1982
Publication Kind : A
Prior PCT appl.: Application Number:CH79000059 ; Publication Number: Click to see the data
IPC:
B29C 65/18
B29C 65/30
B29C 65/00
B29C 65/34
F16L 47/02
F16L 47/03
B PERFORMING OPERATIONS; TRANSPORTING
29
WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
C
SHAPING OR JOINING OF PLASTICS; SHAPING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; AFTER- TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
65
Joining of preformed parts; Apparatus therefor
02
by heating, with or without pressure
18
using heated tool
B PERFORMING OPERATIONS; TRANSPORTING
29
WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
C
SHAPING OR JOINING OF PLASTICS; SHAPING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; AFTER- TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
65
Joining of preformed parts; Apparatus therefor
02
by heating, with or without pressure
18
using heated tool
24
characterised by the means for heating the tool
30
Electrical means
B PERFORMING OPERATIONS; TRANSPORTING
29
WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
C
SHAPING OR JOINING OF PLASTICS; SHAPING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; AFTER- TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
65
Joining of preformed parts; Apparatus therefor
B PERFORMING OPERATIONS; TRANSPORTING
29
WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
C
SHAPING OR JOINING OF PLASTICS; SHAPING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; AFTER- TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
65
Joining of preformed parts; Apparatus therefor
02
by heating, with or without pressure
34
using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
F MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
16
ENGINEERING ELEMENTS OR UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
L
PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
47
Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics
02
Welded joints; Adhesive joints
F MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
16
ENGINEERING ELEMENTS OR UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
L
PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
47
Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics
02
Welded joints; Adhesive joints
03
Welded joints with an electrical resistance incorporated in the joint
CPC:
F16L 47/03
B29C 65/342
B29C 65/3476
B29C 66/0242
B29C 66/5221
B29C 66/5229
B29C 66/8748
B29C 66/91645
B29C 66/91651
B29C 66/944
B29C 66/949
B29C 66/9674
Applicants: STURM WERNER
Inventors: Sturm Werner
Agents: Roylance, Abrams, Berdo &; Farley
Priority Data: 00469678 28.04.1978 CH
Title: (EN) Method and apparatus for joining thermoplastic line elements
Abstract: front page image
(EN)

Electric welding sleeves used more particularly with larger pipe diameters have a heating wire winding which is under compressive stress due to the shrinkage of the sleeve member. This compressive stress and the elongation of the resistance heating wire occurring during the welding process can lead to a lateral displacement and contact with adjacent turns. The welding apparatus (4) used for welding such sleeves obviates these difficulties in that the overall welding time of the electric welding sleeve (15) is subdivided into a preheating time and a welding time. During the preheating time a partial power is used and during the welding time the full welding power. If the welding power is taken from an alternating current system the welding process can start with half the power by arranging a diode (8) in the welding circuit (2) and at the end of the preheating time the diode is bridged by a switching stage (10).


Also published as:
WO/1979/001000