Patent ID: 9249703
Filing Date: 2016-02-02
CPC Classification: F01N

Claim Text:
1. A compact muffler for small engines, comprising: a spiral-shaped main chamber extending from an inlet port to an outlet port; a pair of outer chambers, the pair sandwiching the main chamber therebetween; and a pair of planar walls, one wall separating the main chamber from one of the pair of outer chambers and the other wall separating the main chamber from the other of the pair of outer chambers, each of the walls having a plurality of perforations therein to allow fluid communication between the main chamber and each of the outer chambers; wherein as the main chamber extends from the inlet port to the outlet port, the perforations are absent in the region proximate to the inlet port and are present in the central region of the main chamber and the region proximate to the outlet port.