Air exhaust by-pass for underwater exhaust systems

In a marine propulsion system for a fishing boat having a motor with an integral underwater exhaust system, the improvement of reducing the fish sensitive low frequency underwater noise generated by the exhaust during low speed operation of the motor comprising a muffled above water outlet to the air for the exhaust, and selectively operated means comprising a throttle controlled selective valving mechanism for rerouting the exhaust through said muffled above water outlet to the air while preventing exhaust emanations from either impinging directly upon the water surface or passing to any underwater level by blocking movement of the exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operation and for allowing the exhaust system to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

In a marine propulsion system for a fishing boat having a motor with an integral underwater exhaust system, the improvement of reducing the fish sensitive low frequency underwater noise generated by the exhaust during low speed operation of the motor comprising a muffled above water outlet to the air for the exhaust, and selectively operated means comprising a selective flapper valve for rerouting the exhaust through said muffled above water outlet to the air while preventing exhaust emanations from either impinging directly upon the water surface or passing to any underwater level by blocking movement of the exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operation and for allowing the exhaust system to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

In a marine propulsion system for a fishing boat having a motor with an integral underwater exhaust system, the improvement of reducing the fish sensitive low frequency underwater noise generated by the exhaust during low speed operation of the motor comprising a muffled above water outlet to the air for the exhaust, and selectively operated means comprising a selective rotary valve for rerouting the exhaust through said muffled above water outlet to the air while preventing exhaust emanations from either impinging directly upon the water surface or passing to any underwater level by blocking movement of the exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operation and for allowing the exhaust system to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

In a marine propulsion system for a fishing boat having a motor with an integral underwater exhaust system, the improvement of reducing the fish sensitive low frequency underwater noise generated by the exhaust during low speed operation of the motor comprising a muffled above water outlet to the air for the exhaust, and selectively operated means comprising dual operating valves for rerouting the exhaust through said muffled above water outlet to the air while preventing exhaust emanations from either impinging directly upon the water surface or passing to any underwater level by blocking movement of the exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operation and or allowing the exhaust system to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

The improvement for an outboard motor having an integral passage for an underwater exhaust system wherein the fish sensitive low frequency underwater noise of the exhaust system during low speed operation of the motor is reduced, said improvement comprising muffler housing means connected to the motor at a location normally above the water level and communicating with the exhaust passage intermediate the ends thereof at a location normally above the water outlet, a muffler disposed within said housing to provide a muffled above water outlet to the air for the exhaust emanations from the motor, and selectively operated means comprising manually controlled selective valving mechanism for rerouting the exhaust through said muffled above water outlet while effectively preventing exhaust emanations from either impinging directly upon the water surface or from passing to any underwater level at low speed operations by blocking movement of exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operations and for allowing the motor to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

The improvement for an outboard motor having an integral passage for an underwater exhaust system wherein the fish sensitive low frequency underwater noise of the exhaust system during low speed operation of the motor is reduced, said improvement comprising muffler housing means connected to the motor at a location normally above the water level and communicating with the exhaust passage intermediate the ends thereof at a location normally above the water outlet, a muffler disposed within said housing to provide a muffled above water outlet to the air for the exhaust emanations from the motor, and selectively operated means comprising a solenoid actuated air exhaust by-pass valve for rerouting the exhaust through said muffled above water outlet while effectively preventing exhaust emanations from either impinging directly upon the water surface or from passing to any underwater level at low speed operations by blocking movement of exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operations and for allowing the motor to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

The improvement for an outboard motor having an integral passage for an underwater exhaust system wherein the fish sensitive low frequency underwater noise of the exhaust system during low speed operation of the motor is reduced, said improvement comprising muffler housing means connected to the motor at a location normally above the water level and communicating with the exhaust passage intermediate the ends thereof at a location normally above the water outlet, a muffler disposed within said housing to provide a muffled above water outlet to the air for the exhaust emanations from the motor, and selectively operated means comprising a mechanically actuated air exhaust by-pass valve for rerouting the exhaust through said muffled above water outlet while effectively preventing exhaust emanations from either impinging directly upon the water surface or from passing to any underwater level at low speed operations by blocking movement of exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operations and for allowing the motor to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

The improvement for an outboard motor having an integral passage for an underwater exhaust system wherein the fish sensitive low frequency underwater noise of the exhaust system during low speed operation of the motor is reduced, said improvement comprising muffler housing means connected to the motor at a location normally above the water level and communicating with the exhaust passage intermediate the ends thereof at a location normally above the water outlet, a muffler disposed within said housing to provide a muffled above water outlet to the air for the exhaust emanations from the motor, and selectively operated means comprising a throttle controlled selective valving mechanism for rerouting the exhaust through said muffled above water outlet while effectively preventing exhaust emanations from either impinging directly upon the water surface or from passing to any underwater level at low speed operations by blocking movement of exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operations and for allowing the motor to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

The improvement for an outboard motor having an integral passage for an underwater exhaust system wherein the fish sensitive low frequency underwater noise of the exhaust system during low speed operation of the motor is reduced, said improvement comprising muffler housing means connected to the motor at a location normally above the water level and communicating with the exhaust passage intermediate the ends thereof at a location normally above the water outlet, a muffler disposed within said housing to provide a muffled above water outlet to the air for the exhaust emanations from the motor, and selectively operated means comprising a selective flapper valve for rerouting the exhaust through said muffled above water outlet while effectively preventing exhaust emanations from either impinging directly upon the water surface or from passing to any underwater level at low speed operations by blocking movement of exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operations and for allowing the motor to retun to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

The improvement for an outboard motor having an integral passage for an underwater exhaust system wherein the fish sensitive low frequency underwater noise of the exhaust system during low speed operation of the motor is reduced, said improvement comprising muffler housing means connected to the motor at a location normally above the water level and communicating with the exhaust passage intermediate the ends thereof at a location normally above the water outlet, a muffler disposed within said housing to provide a muffled above water outlet to the air for the exhaust emanations from the motor, and selectively operated means comprising a selective rotary valve for rerouting the exhaust through said muffled above water outlet while effectively preventing exhaust emanations from either impinging directly upon the water surface or from passing to any underwater level at low speed operations by blocking movement of exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operations and for allowing the motor to return to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.

The improvement for an outboard motor having an integral passage for an underwater exhaust system wherein the fish sensitive low frequency underwater noise of the exhaust system during low speed operation of the motor is reduced, said improvement comprising muffler housing means connected to the motor at a location normally above the water level and communicating with the exhaust passage intermediate the ends thereof at a location normally above the water outlet, a muffler disposed within said housing to provide a muffled above water outlet to the air for the exhaust emanations from the motor, and selectively operated means comprising dual operating butterfly valves for rerouting the exhaust through said muffled above water outlet while effectively preventing exhaust emanations from either impinging directly upon the water surface or from passing to any underwater level at low speed operations by blocking movement of exhaust to the water level at a point above the water surface for discharge through the muffled outlet to the air at low speed operations and for allowing the motor to retun to normal underwater exhaust conditions at faster speed operation where the overall sound frequencies become higher.