Electric heating – Metal heating – For bonding with pressure
Reexamination Certificate
1999-09-27
2001-09-11
Shaw, Clifford C. (Department: 1725)
Electric heating
Metal heating
For bonding with pressure
C219S064000, C219S161000
Reexamination Certificate
active
06288355
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a welding method in which a body substantially open at opposite ends is formed from a flat metal sheet and welded along its edges. For example, roller seam welding involves forming the body with overlapping edges and feeding the region of overlap to welding rollers. The invention further relates to apparatus for carrying out the method.
It is known to form hollow cylindrical bodies from flat metal sheets, e.g.. can bodies or ventilation pipes, the edges being butted against one another or an overlapping region of sheet metal being formed which is then joined by seam welding. As is known, seam welding involves the bodies to be welded being fed, preceding the welding zone, through a large number of rollers adapted to match the cross-section of the body being welded, with these rollers forming a passage which surrounds the body, or a guiding tool (so-called diabolo rolls according to Swiss Patent CH-A-671904). These roller guide tools maintain the shape of the body and press its longitudinal edges into a Z-shaped rail which takes care of the butt-jointed positioning or overlapping of the longitudinal edges which is required for welding. Seam welding then takes place by advancing the metal sheet through the guiding tools with the welding rollers operating on the overlap, and normally involves the use of wire electrodes.
In the case of metal sheets that incorporate reliefs or recesses, or that are composed of different thicknesses of material or else have been cut out in such a way that the end surface of the rounded body is not at right-angles to the longitudinal axis, or direction of the weld seam, these conventional roller guiding tools have been known to cause problems since there is no guarantee that the workpiece will be correctly guided and centered. Therefore to date such welds have not been produced using the conventional welding machines.
It is therefore an object of this invention to devise a method of welding bodies, more particularly sheet metal casings, by which it is possible to weld a body formed from a sheet metal blank of any desired shape and even metal sheet incorporating recesses or differences in material thickness or hardness.
SUMMARY OF THE INVENTION
In the case of the method of welding a body substantially open at opposites ends this object may be achieved by introducing the body into a preform, holding it therein and feeding it together with the preform to the welding station.
The fact that the body is held in a preform and fed along with the preform to the welding station means that it is also a straightforward matter to weld bodies formed from metal sheets incorporating the shaping, recesses, etc. referred to above.
A welding apparatus to achieve this object, comprises welding rollers and wire electrodes for welding a butt seam or a lap seam. Additional features include at least one preform (
7
) for the introduction of at least one preformed body to be welded, clamping means (
11
,
12
,
14
) for holding the body in the preform, and driving means for driving the preform in the direction of welding.
REFERENCES:
patent: 3585337 (1971-06-01), Rudd
patent: 3627964 (1971-12-01), Morris
patent: 3834010 (1974-09-01), Wolfe et al.
patent: 4070887 (1978-01-01), Hankin
patent: 4389556 (1983-06-01), Nozawa et al.
patent: 4525617 (1985-06-01), Saito
patent: 4675489 (1987-06-01), Opprecht et al.
patent: 4719329 (1988-01-01), Matsuno et al.
patent: 4805795 (1989-02-01), Sato et al.
patent: 4842186 (1989-06-01), Doyle et al.
patent: 4856312 (1989-08-01), Alnauzer et al.
patent: 5011064 (1991-04-01), Fuss
patent: 5344062 (1994-09-01), Krengel et al.
patent: 5841090 (1998-11-01), Taina
patent: 0 023 753 (1981-02-01), None
patent: 0 289 745 (1988-11-01), None
patent: 1 201 202 (1970-05-01), None
Elpatronic AG
McCormick Paulding & Huber LLP
Shaw Clifford C.
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