Exhaust double pipe of an internal combustion engine

Claim 1

A double-walled exhaust pipe for use with an internal combustion engine of a vehicle comprising: an inner exhaust pipe having first and second ends, an outer pipe assembly surrounding said inner pipe, said outer pipe assembly comprising first and second outer pipes, each having inner and outer ends, said inner end of said first outer pipe being coupled to said inner end of said second outer pipe, wherein the coupling between said first and second outer pipes is a tubular spacer fitted into the inner ends of said first and second outer pipes, and allows sliding movement between one of said outer pipes and said spacer, said spacer comprising a straight pipe, one end of which is welded to said inner end of said first outer pipe, and the other end of which is slidably fitted into the inner end of said second outer pipe, a first mounting flange, said outer end of said first outer pipe being welded to said first mounting flange together with said first end of said inner pipe, and a second mounting flange, the outer end of said second outer pipe being welded to said second mounting flange together with said second end of said inner pipe.