Patent ID: 7743500

Claim:
A method for manufacturing an exhaust gas treatment device for an internal combustion engine of a motor vehicle, comprising the steps of: axially inserting at least one exhaust gas treatment cartridge into a cylindrical casing that is open on at least one side, wherein the casing has an initial inside cross-section larger than an outside cross-section of the exhaust gas treatment cartridge; axially inserting at least one funnel into an axial end region of the casing, the at least one funnel comprising a first end region of a first outside cross-section and a second end region having a tapered outside cross-section, the first end region of the at least one funnel being proximal to the at least one exhaust gas treatment cartridge, and wherein the first outside cross-section of the first end region of the funnel is smaller than the initial inside cross-section of the casing; and, reducing the cross-section of the casing such that the casing subsequently has a first ultimate inside cross-section equal to the outside cross-section of the exhaust gas treatment cartridge in a first region of the casing in which the at least one exhaust gas treatment cartridge is arranged, and a second ultimate inside cross-section equal to the first outside cross-section of the first end region of the funnel in a second end region of the casing in which the funnel is arranged, wherein both of the outside cross-section of the at least one exhaust gas treatment cartridge and the first outside cross-section of the first end region of the at least one funnel are reduced during the reducing step.