Method for imparting resistance to axial displacement of convolutions in a convoluted catalyst substrate

Claim 1

A method for imparting resistance to axial displacement of convolutions in a convoluted substrate of the type suitable for use in a catalyst unit, comprising a substrate coated with a layer of refractory oxide and useful in the purification of exhaust gases, the substrate comprising convolutions of superimposed plain and corrugated strips of metal wound around a common axis to form a generally cylindrical substrate having end faces transverse to the axis of the cylindrical substrate wherein convolutions of plain metal strip are spaced apart by convolutions of corrugated metal strip to define a plurality of passageway channel extending axially between the end faces of the substrate so that exhaust gas under pressure can pass axially through the substrate wherein the method comprises making from one to four weld runs each across a diameter of one of the end faces of the substrate so as to bridge superimposed convolutions of plain and the corrugated strip thereby increasing the resistance of the bridged convolutions to axial displacement relative to each other in response to displacing forces generated by exhaust gases passing through the channels.

Claim 2

A method for imparting resistance to axial displacement of convolutions in a convoluted substrate of the type suitable for use in a catalyst unit, comprising a substrate coated with a layer of refractory oxide and useful in the purification of exhaust gases, the substrate comprising convolutions of superimposed plain and corrugated strips of metal wound around a common axis to form a generally cylindrical substrate having end faces transverse to the axis of the cylindrical substrate wherein convolutions of plain metal strip are spaced apart by convolutions of corrugated metal strip to define a plurality of passageway channel extending axially between the end faces of the substrate so that exhaust gas under pressure can pass axially through the substrate wherein the method comprises making from one to four weld runs each across a diameter of one of the end faces of the substrate so as to bridge superimposed convolutions of plain and the corrugated strip thereby increasing the resistance of the bridged convolutions to axial displacement relative to each other in response to displacing forces generated by exhaust gases passing through the channels.