Exhaust system comprising silencers with reduced wall connections

Claim 1

A SILENCING DEVICE FOR THE EXHAUST SYSTEM OF AN INTERNAL COMBUSTION ENGINE COMPRISING AN OUTER PIPE HAVING A REDUCED DIAMETER INLET BUSHING AT ONE END THEREOF AND A REDUCED DIAMETER OUTLET BUSHING AT ITS OTHER END, AN INNER PIPE HAVING AN INLET END SUPPORTED BY SAID INLET BUSHING AND AN OUTLET END SUPPORTED BY SAID OUTLET BUSHING, AN INTERMEDIATE PIPE AFFIXED AT ONE OF ITS ENDS TO THE PERIPHERY OF SAID INNER PIPE AND EXTENDING AT A SPACED DISTANCE THEREFROM ALONG A PORTION OF THE LENGTH OF SAID INNER PIPE ADJACENT TO ONE OF SAID BUSHINGS, A REDUCED DIAMETER PORTION OF SAID OUTER PIPE BEING IN ENGAGEMENT WITH SAID INNER PIPE AROUND ITS PERIPHERY TO DEFINE WITH SAID ONE OF SAID BUSHINGS A FIRST SILENCING CHAMBER ENCOMPASSING SAID INTERMEDIATE PIPE, THE OTHER END OF SAID INTERMEDIATE PIPE BEING OPEN TO SAID SILENCING CHAMBER, A PLURALITY OF PERFORATIONS FORMED IN SAID INNER PIPE ADJACENT TO SAID ONE END OF SAID INTERMEDIATE PIPE WHEREBY SAID INTERMEDIATE PIPE FUNCTIONS AS A TUNING NECK FOR SAID FIRST SILENCING CHAMBER, AND A PLURALITY OF PERFORATIONS FORMED IN THE PORTION OF SAID INNER PIPE BETWEEN SAID REDUCED DIAMETER PORTION AND THE OTHER OF SAID BUSHINGS FOR FORMING A SILENCING CHAMBER BETWEEN SAID PORTION OF SAID INNER PIPE AND THE PORTION OF SAID OUTER PIPE BETWEEN SAID REDUCED DIAMETER PORTION AND THE OTHER OF SAID BUSHINGS WHICH FUNCTIONS AS A SPIT CHAMBER.