Electric heating – Metal heating – For bonding with pressure
Reexamination Certificate
2000-03-14
2001-08-28
Dunn, Tom (Department: 1725)
Electric heating
Metal heating
For bonding with pressure
C219S119000, C219S082000, C219S083000
Reexamination Certificate
active
06281467
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field
This invention pertains to a welding arrangement and process for joining parts in various weld configurations. More particularly, the process relates to the use of a resistively heated cover sheet that provides conductive heating of the weld zone of the parts to be welded and constrains the molten part material to the weld area.
2. Background
As consumer demand for more fuel efficient vehicles increases, as well as increased government regulation of fleet fuel economy, the use of light-weight materials such as aluminum for automotive components is becoming more attractive. As part of this effort, aluminum parts with continuous joints are of interest; however, the processes used to fabricate these joints are expensive. These processes include laser welding, gas tungsten arc (GTA) welding, and electron beam welding.
Thus it is an object of the present invention to provide an inexpensive continuous wed.
It is an object of the present invention to provide conductive heating of a weld zone.
It is an object of the present invention to prevent metal expulsion from the weld.
It is an object of the present invention to provide an improved method of welding aluminum.
It is an object of the present invention to provide a weld of good weld integrity.
It is an object of the present invention to reduce electrode wear rates.
It is a further object of the present invention to provide a weld with minimal evidence of cracking or porosity.
SUMMARY OF THE INVENTION
To meet these objects, the present invention features placing two electrically-conducting parts to be joined, typically metals although electrically conductive plastics may also be used, juxtaposed one to the next to form a weld zone. One or more covering sheets of a higher-melting, electrically-conductive material than the parts to be joined is placed next to the weld zone. Oppositely charged electrodes are positioned and aligned to cause a current to flow through the covering sheet and the weld zone of the materials to be joined. Resistance heating of the cover sheets) with subsequent conductive heating of the weld zone produces sufficient heat to melt and weld the parts together. The covering sheet(s) not only provides conduction heating of the weld zone but it also provides constraint to the molten metal to prevent expulsion of molten part materials from the weld pool.
In a common arrangement used with the present invention, the weld zone of the parts to be joined is sandwiched between two covering sheets with oppositely charged electrodes then placed in contact with the covering sheets. By using rotating circular electrodes, the parts can be joined in a continuous seam weld. However, it is to be realized that the method may also be used for intermittent and spot welds using appropriate electrode configurations.
A wide variety of materials can be joined including aluminum, lead, copper, brass and other alloys provided the materials to be joined melt are at a lower temperature than the covering material. The cover sheet typically is a steel such as SAE 1010/1008 but can include various other covering materials including cobalt, nickel, and titanium based alloys that melt at a temperature greater than the parts to be joined. Various weld-zone configurations may also be used including butt, tee, lap and mash configurations.
The foregoing and other objects, features and advantages of the invention will become apparent from the following disclosure in which one or more preferred embodiments of the invention are described in detail and illustrated in the accompanying drawings. It is contemplated that variations in procedures, structural features and arrangement of parts may appear to a person skilled in the art without departing from the scope of or sacrificing any of the advantages of the invention.
REFERENCES:
patent: 1052490 (1913-02-01), Linden et al.
patent: 1176614 (1916-03-01), Stanley
patent: 1225373 (1917-05-01), Thomson
patent: 1308781 (1919-07-01), Gravell
patent: 1568080 (1926-01-01), Meadowcroft
patent: 1618764 (1927-02-01), Lunn
patent: 1659920 (1928-02-01), Murray, Jr.
patent: 1664030 (1928-03-01), Gravell
patent: 1880095 (1932-09-01), Ledwinka
patent: 2599045 (1952-06-01), Brolaski
patent: 2620424 (1952-12-01), Otto
patent: 2790891 (1957-04-01), Welsh
patent: 2914641 (1959-10-01), Yuhasz
patent: 3015713 (1962-01-01), Eckler et al.
patent: 3374530 (1968-03-01), Flanders et al.
patent: 47-48780 B (1972-08-01), None
patent: 58-81577 A (1983-05-01), None
Gould Jerry E.
Lehman Lawrence R.
Workman David P.
Cooke Colleen P.
Dunn Tom
Edison Welding Institute
Pollick Philip J.
LandOfFree
Conductive heat resistance seam welding does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Conductive heat resistance seam welding, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Conductive heat resistance seam welding will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2514624