Electrically weldable plastic fitting

• US 5,670,012 A
• Filed: 01/05/1995
• Issued: 09/23/1997
• Est. Priority Date: 01/10/1994
• Status: Expired due to Fees

• Current Assignee: Georg Fischer Rohrleitungssysteme AG (Georg Fischer AG)
• Original Assignee: Georg Fischer Rohrleitungssysteme AG (Georg Fischer AG)
• Inventors: Porfido, Erasmo, Bamberger, Michael
• Primary Examiner(s): Simmons, David A.
• Assistant Examiner(s): Rivard, Paul M.
• Application Number:
  US08/369,405
• Time in Patent Office: 992 Days
• Field of Search: 156/158, 156/304.2, 156/304.6, 156/273.9, 156/274.2, 156/379.7, 219/59.1, 219/61.2, 219/497, 219/535, 219/544
• US Class Current: 156/379.7
• CPC Class Codes: B29C 65/342 comprising at least a single wire, e.g. in the form of a winding
• CPC Class Codes: B29C 65/344 being a woven or non-woven fabric or being a mesh
• CPC Class Codes: B29C 65/3468 characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special electrical connectors of windings B29C65/3668 takes precedence
• CPC Class Codes: B29C 65/3476 being metallic
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/5221 for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
• CPC Class Codes: B29C 66/5229 involving the use of a socket
• CPC Class Codes: B29C 66/91214 by measuring the electrical resistance of a resistive element belonging to one of the parts to be welded, said element acting, e.g. as a thermistor
• CPC Class Codes: B29C 66/91317 by measuring the electrical resistance
• CPC Class Codes: B29C 66/91655 by controlling or regulating the current intensity
• CPC Class Codes: F16L 47/03 Welded joints with an electrical resistance incorporated in the joint

Abstract

A fitting formed as a welding sleeve has, preferably, two heating elements and is provided in the region of the plug contacts with a plate which can be inserted into a recess. On the plate is arranged a resistor and the connections for measuring the ohmic resistance by means of a welding apparatus. By measuring the resistance, the type of the fitting can be identified and the current to be fed to the welding apparatus determined.

Claims

1. An electrically weldable plastic fitting having at least one welding part having a heating element consisting of a resistance wire for the production of a weld connection wherein the heating element is connected with plug contacts for the feeding of current from a welding apparatus, the improvement which comprises a resistor having a given resistance located on the fitting, the resistor having connections for connection to the welding apparatus wherein the resistance of the resistor serves to identify the fitting type wherein the resistor together with the connections are arranged on a plastic plate which is placed in a recess formed on the fitting.

2. A fitting according to claim 1 wherein the resistor is arranged on one surface of the plate and the connections on the other surface of the plate wherein the resistor and connections are connected with each other by lines extending through the plate.

3. A fitting according to claim 1 wherein the recess is provided with guide grooves.

4. A fitting according to claim 1 wherein the connections are formed as two flat contact surfaces arranged parallel to each other on the plate.

5. A fitting according to claim 1 wherein the connections are formed on at least one peripheral side of the plate in arcuate recesses.

6. A fitting according to claim 1 wherein the fitting is formed as a welding sleeve for connection to at least one pipe and includes at least one resistance wire wherein the resistor has an ohmic resistance which is determined as a function of the number of resistance wires.