Exhaust muffler for two-stroke cycle engine

Claim 2

An exhaust muffler for two-stroke cycle engines, comprising: a. a generally cylindrical muffler housing having an axial opening at one end and an outlet opening at the other end; b. an inlet tube having opposite inlet and outlet ends; c. means mounting said inlet tube along the axis of said housing with said inlet end thereof extending from said axial opening for connection with the exhaust discharge port of an engine; d. means forming a closed tuning chamber in said housing at least partially surrounding said tube adjacent said inlet end; e. a wall of said tube having a single axially and circumferentially extending opening leading to said tuning chamber; f. louver means mounted on said tube in said tuning chamber adjacent an upstream side of said opening and diverging away from said opening into said chamber in a downstream direction to shield said single opening to substantially prevent pressure waves from leaving said tuning chamber in a downstream direction while directing energy developed in the tuning chamber toward said engine to enhance the performance thereof; and g. said housing containing silencing means downstream from said tuning chamber.

Claim 3

An exhaust muffler for two-stroke cycle engines, comprising: a. a generally cylindrical muffler housing having an axial opening at one end and an outlet opening at the other end; b. an inlet tube having opposite inlet and outlet ends; c. means mounting said inlet tube along the axis of said housing with said inlet end thereof extending from said axial opening for connection with the exhaust discharge port of an engine; d. means forming a closed tuning chamber in said housing at least partially surrounding said tube adjacent said inlet end; e. a wall of said tube having a single opening leading to said tuning chamber; f. a louver mounted on said tube in said tuning chamber to shield said single opening to substantially prevent pressure waves from leaving said tuning chamber in a downstream direction while directing energy developed in the tuning chamber toward said engine to enhance the performance thereof; g. said housing containing silencing means downstream from said tuning chamber; h. said outlet end being open and terminating in a second closed tuning chamber in said housing; and i. means including openings in said tube wall between the ends thereof to provide an exhaust gas flow path to said outlet opening of said housing.

Claim 4

An exhaust muffler for two-stroke cycle engines, comprising: a. a generally cylindrical muffler housing having an axial opening at one end and an outlet opening at the other end; b. an inlet tube having opposite inlet and outlet ends; c. means mounting said inlet tube along the axis of said housing with said inlet end thereof extending from said axial opening for connection with the exhaust discharge port of an engine; d. means forming a closed tuning chamber in said housing at least partially surrounding said tube adjacent said inlet end; e. a wall of said tube having a single opening leading to said tuning chamber; f. a louver mounted on said tube in said tuning chamber to shield said single opening to substantially prevent pressure waves from leaving said tuning chamber in a downstream direction while directing energy developed in the tuning chamber toward said engine to enhance the performance thereof; g. said housing containing silencing means downstream from said tuning chamber; h. said outlet end being open and terminating in a second closed tuning chamber in said housing; and i. means including openings in said tube wall between the ends thereof to provide an exhaust gas flow path to said outlet opening of said housing.

Claim 5

The muffler of claim 10 wherein said housing includes a resonator chamber at least partially surrounding said tube between said tuning chamber, said openings in said tube wall leading thereto.

Claim 6

The muffler of claim 3 including an exhaust gas collector compartment in said other end of said housing opposite said second tuning chamber from said resonator chamber, said outlet opening leading from said compartment, and a plurality of pipes leading from said resonator chamber to said compartment to permit exhaust gas flow therebetween.

Claim 7

An exhaust unit for two-stroke cycle engines, comprising: a. a housing; b. a tube; c. means mounting said tube in said housing for connection with the exhaust noise and gas discharge port of an engine; d. means forming a chamber in said housing adjacent said tube; e. a side wall of said tube having an axially extending opening leading to said chamber to permit exhaust noise sound waves to enter said chamber; and f. a megaphone portion mounted on the upstream edge of said opening on said tube in said chamber, said megaphone portion diverging from said opening into said chamber in a downstream direction over at least part of said opening to substantially prevent reflected sound waves from leaving said chamber in a dIrection away from the engine while directing sound wave energy developed in said chamber toward the engine to enhance the performance thereof.

Claim 8

An exhaust unit for two-stroke cycle engines, comprising: a. a housing; b. a tube; c. means mounting said tube in said housing for connection with the exhaust noise and gas discharge port of an engine; d. means forming a chamber in said housing adjacent said tube; e. a side wall of said tube having an axially extending opening leading to said chamber to permit exhaust noise sound waves to enter said chamber; and f. a megaphone portion mounted on the upstream edge of said opening on said tube in said chamber, said megaphone portion diverging from said opening into said chamber in a downstream direction over at least part of said opening to substantially prevent reflected sound waves from leaving said chamber in a dIrection away from the engine while directing sound wave energy developed in said chamber toward the engine to enhance the performance thereof.

Claim 9

The apparatus of claim 5 wherein a second chamber is formed in said housing at an outlet end of said tube to reflect sound waves so as to enhance engine performance at low engine speeds.

Claim 10

Exhaust apparatus for two-stroke cycle engines, comprising: a. an exhaust tube having an inlet end adapted to be connected to the exhaust discharge port of an engine, an exhaust outlet end, and an axially extending opening in a side wall thereof between said ends; b. housing means forming a tuning chamber in communication with said opening; and c. louver means mounted on the upstream side of said opening on said tube in said chamber adjacent said opening, said louver diverging away from said opening in a downstream direction over at least part of said opening to act with said chamber as a megaphone to enhance engine performance.

Claim 11

Exhaust apparatus for two-stroke cycle engines, comprising: a. an exhaust tube having an inlet end adapted to be connected to the exhaust discharge port of an engine, an exhaust outlet end, and an axially extending opening in a side wall thereof between said ends; b. housing means forming a tuning chamber in communication with said opening; and c. louver means mounted on the upstream side of said opening on said tube in said chamber adjacent said opening, said louver diverging away from said opening in a downstream direction over at least part of said opening to act with said chamber as a megaphone to enhance engine performance.

Claim 12

The apparatus of claim 7 wherein the area of said opening is approximately 70 percent of the cross-sectional area of said exhaust tube.