Device for catalytic cleaning of motor vehicle exhaust gases

A device for cleaning gases exiting from a vehicle motor exhaust pipe, comprising an outer tubular housing having a first connection portion at one end and a second connection portion at the other end, each connection portion positioned and arranged to overlie and be connected to a part of the exhaust pipe;

• first and second transition portions of gradually increasing diameter extending radially outwardly of said first and second connection portions, respectively;
• a monolith portion connected at each end to each of said first and second transition portions at ends which are each remote from said first and second connection portions, respectively;
• a monolith in said monolith portion having a catalytically active coating and an end face;
• an inner shell of a temperature resistant plate metal in said housing spaced radially inwardly of the interior of said housing in each of said first and second transition portions, a spacer matting positioned between the interior of said housing and said monolith and comprising a material permitting variable thermal expansion of said housing and said monolith, said spacer matting having a side face protected by a protective layer, said inner shell having at least one end portion extending into said monolith portion with a base portion connected to said tubular housing and an end face portion overlapping portions of the monolith end face to maintain the monolith in position, securing means securing said inner shell base portion to said tubular housing at said monolith portion, said inner shell having another end portion adjacent said first and second connection portions which are free for thermal expansion.