Patent ID: 8876566
Filing Date: 2014-11-04
Classification: B63H,F01N

Abstract:
1. A marine drive comprising an inboard engine having an exhaust system discharging exhaust from said engine externally of a marine vessel operating in a body of water, an exhaust conduit receiving said exhaust and discharging said exhaust externally of said vessel, said exhaust conduit comprising an exhaust pipe having a main exhaust flow chamber and an auxiliary idle relief chamber, said main exhaust flow chamber and said auxiliary idle relief chamber located within a hull of the marine vessel, said auxiliary idle relief chamber venting exhaust above the surface of said body of water; wherein said exhaust from said main exhaust flow chamber is discharged below said surface of said body of water; said exhaust flows downwardly in said main exhaust flow chamber; and said exhaust flows upwardly in said auxiliary idle relief chamber; and wherein said main exhaust flow chamber has a downward extension section through which said exhaust flows downwardly, said auxiliary relief chamber has an upward extension section through which said exhaust flows upwardly, said exhaust pipe has a transfer passage extending laterally between said downward extension section and a lower portion of said upward extension section, such that said exhaust flows downwardly in said downward extension section passed said transfer passage and is discharged at a submerged location below said surface of said body of water, and such that a portion of said exhaust that is flowing downwardly in said downward extension section separates from said exhaust by flowing laterally through said transfer passage into said auxiliary idle relief chamber and then upwardly in said upward extension section.