Fuel porting for two-cycle internal combustion engine

Claim 2

A variable speed, two-cycle crankcase compression, internal combustion engine, comprising: engine housing structure including a cylinder and a crankcase, a piston having a head and a body mounted for reciprocation in the cylinder between top and bottom dead center positions, at least one transfer passage in the engine housing structure having an opening in communication with the crankcase and having an opening in communication with the cylinder above the piston head in bottom dead center position, a fuel intake chamber for receiving fuel from a supply source, reed valve means for controlling the flow of fluid through the intake chamber, and passage means formed in the engine housing structure and communicating with the intake chamber downstream of the reed valve means, the passage means including intake porting in the cylinder wall in the bottom dead center position of the piston and providing for substantially direct flow of fuel from the reed valve means into the space below the level of the lower edge of the piston at the side presented toward the porting when the piston rises substantially above the bottom dead center position, the passage means further including additional porting in the cylinder wall circumferentially offset from said intake porting and located axially of the cylinder in a position presented toward the bottom dead center position of the piston body, and the piston body being spaced from the cylinder wall in the region of said additional porting to provide a passage between the piston and the cylinder extended downwardly and communicating with the crankcase even when the piston is in bottom dead center position.

Claim 3

An engine as defined in claim 1 in which said passage means in the engine housing structure still further includes porting in the cylinder wall above the piston head in bottom dead center position of the piston.

Claim 4

An engine as defined in claim 2 in which said passage means still further includes a portion interconnecting said porting in the cylinder wall above the piston head with the opening of the transfer passage above the piston head, and said interconnecting portion being located in a region closely adjacent to the piston head when the piston is in bottom dead center position.

Claim 5

A variable speed, two-cycle crankcase compression, internal combustion engine, comprising: engine housing structure including a cylinder and a crankcase, a piston mounted for reciprocation in the cylinder between top and bottom dead center positions, the piston having a head and a hollow body with bearing means for cooperation with a wrist pin having an axis lying in a plane containing the axis of the cylinder and piston, a fuel intake chamber for receiving fuel from a supply source, the fuel intake chamber being located in offset relation to said axial plane toward one side thereof, reed valve means for controlling the flow of fluid through the intake chamber in a path directed transverse to the axial plane substantially radially toward the bottom dead center position of the piston, and passage means formed in the engine housing structure and communicating with the intake chamber downstream of the reed valve means, the passage means including porting in the engine housing structure at least a part of which is in the cylinder wall in the bottom dead center position of the piston and provides for substantially direct flow of fuel substantially radially of the cylinder from the reed valve means into the space below the level of the lower edge of the piston at the side presented toward the porting when the piston rises substantially above the bottom dead center position, and the passage means further including at least one portion communicating with the fuel intake chamber throughout the piston stroke and having porting through the cylinder wall above the piston in bottom dead center position, and the passage means still further including a port through the cylinder wall in a position below the piston head but above the lower edge of the piston when the piston is in bottom dead center position, and the position of said port being in the region of the axial plane of the wrist pin, and the body of the piston below the piston head having a side wall spaced from the cylinder wall in the region of said port to provide a passage between the piston and the cylinder extended downwardly and communicating with the crankcase even when the piston is in bottom dead center position.

Claim 6

A variable speed, two-cycle crankcase compression, internal combustion engine, comprising: engine housing structure including a cylinder and a crankcase, a piston mounted for reciprocation in the cylinder between top and bottom dead center positions, the piston having a head and a hollow body with bearing means for cooperation with a wrist pin having an axis lying in a plane containing the axis of the cylinder and piston, a fuel intake chamber for receiving fuel from a supply source, the fuel intake chamber being located in offset relation to said axial plane toward one side thereof, reed valve means for controlling the flow of fluid through the intake chamber in a path directed transverse to the axial plane substantially radially toward the bottom dead center position of the piston, and passage means formed in the engine housing structure and communicating with the intake chamber downstream of the reed valve means, the passage means including porting in the engine housing structure at least a part of which is in the cylinder wall in the bottom dead center position of the piston and provides for substantially direct flow of fuel substantially radially of the cylinder from the reed valve means into the space below the level of the lower edge of the piston at the side presented toward the porting when the piston rises substantially above the bottom dead center position, and the passage means further including at least one portion communicating with the fuel intake chamber throughout the piston stroke and having porting through the cylinder wall above the piston in bottom dead center position, and the passage means still further including a port through the cylinder wall in a position below the piston head but above the lower edge of the piston when the piston is in bottom dead center position, and the position of said port being in the region of the axial plane of the wrist pin, and the body of the piston below the piston head having a side wall spaced from the cylinder wall in the region of said port to provide a passage between the piston and the cylinder extended downwardly and communicating with the crankcase even when the piston is in bottom dead center position.

Claim 7

A variable speed, two-cycle crankcase compression, internal combustion engine, comprising: engine housing structure including a cylinder and a crankcase, a piston mounted for reciprocation in the cylinder between top and bottom dead center positions, the piston having a head and a hollow body with bearing means for cooperation with a wrist pin having an axis lying in a plane containing the axis of the cylinder and piston, a fuel intake chamber for receiving fuel from a supply source, the fuel intake chamber being located in offset relation to said axial plane toward one side thereof, reed valve means for controlling the flow of fluid through the intake chamber, and passage means formed in the engine housing structure and communicating with the intake chamber downstream of the reed valve means, the passage means including a port through the cylinder wall in a position below the piston head but at least in large part above the lower edge of the piston when the piston is in bottom dead center position, and the position of said port being in the region of the axial plane of the wrist pin, and the body of the piston below the piston head having a side wall spaced from the cylinder wall in the region of said port and extending downwardly to the lower edge of the body of the piston to provide a passage between the piston and the cylinder extended downwardly and communicating with the crankcase even when the piston is in bottom dead center position.

Claim 8

A variable speed, two-cycle crankcase compression, internal combustion engine, comprising: engine housing structure including a cylinder and a crankcase, a piston mounted for reciprocation in the cylinder between top and bottom dead center positions, the piston having a head and a hollow body with bearing means for cooperation with a wrist pin having an axis lying in a plane containing the axis of the cylinder and piston, a fuel intake chamber for receiving fuel from a supply source, the fuel intake chamber being located in offset relation to said axial plane toward one side thereof, reed valve means for controlling the flow of fluid through the intake chamber, and passage means formed in the engine housing structure and communicating with the intake chamber downstream of the reed valve means, the passage means including a port through the cylinder wall in a position below the piston head but at least in large part above the lower edge of the piston when the piston is in bottom dead center position, and the position of said port being in the region of the axial plane of the wrist pin, and the body of the piston below the piston head having a side wall spaced from the cylinder wall in the region of said port and extending downwardly to the lower edge of the body of the piston to provide a passage between the piston and the cylinder extended downwardly and communicating with the crankcase even when the piston is in bottom dead center position.

Claim 9

An engine as defined in claim 5 in which said passage means includes a port through the cylinder wall in the region of said axial plane at each side of the cylinder, and in which both side walls of the piston are spaced from the cylinder wall to provide a passage communicating with the crankcase at each side.

Claim 10

An engine as defined in claim 5 in which the passage means in the engine housing structure further includes intake porting in the cylinder wall in the region of the bottom dead center position of the piston at the side of the piston adjacent the fuel intake chamber, said porting being dimensioned and positioned axially of the cylinder so that the porting is open to the crankcase even in bottom dead center position of the piston.

Claim 11

An engine as defined in claim 5 in which the passage means in the engine housing structure further includes intake porting in the cylinder wall in the region of the bottom dead center position of the piston at the side of the piston adjacent the fuel intake chamber, said porting being dimensioned and positioned axially of the cylinder so that the porting is closed by the body of the piston when the piston is in bottom dead center position.

Claim 12

A variable speed, two-cycle crankcase compression, internal combustion engine, comprising: engine housing structure including a cylinder and a crankcase, a piston mounted for reciprocation in the cylinder between top and bottom dead center positions, the piston having a head and a hollow body with bearing means for cooperation with a wrist pin having an axis lying in a plane containing the axis of the cylinder and piston, a fuel intake chamber for receiving fuel from a supply source, reed valve means for controlling the flow of fluid through the intake chamber, and passage means formed in the engine housing structure and communicating with the intake chamber downstream of the reed valve means, the passage means having a port through the cylinder wall in a position below the piston head but at least in large part above the lower edge of the piston when the piston is in bottom dead center position, and said port communicating with said fuel intake chamber and the position of said port being in the region of the axial plane of the wrist pin, and the body of the piston below the piston head having a side wall spaced from the cylinder wall in the region of said port and extending downwardly to the lower edge of the body of the piston to provide a passage between the piston and the cylinder extended downwardly and communicating with the crankcase even when the piston is in bottom dead center position.

Claim 13

A variable speed, two-cycle crankcase compression, internal combustion engine, comprising: engine housing structure including a cylinder and a crankcase, a piston mounted for reciprocation in the cylinder between top and bottom dead center positions, the piston having a head and a hollow body with bearing means for cooperation with a wrist pin having an axis lying in a plane containing the axis of the cylinder and piston, a fuel intake chamber for receiving fuel from a supply source, reed valve means for controlling the flow of fluid through the intake chamber, and passage means formed in the engine housing structure and communicating with the intake chamber downstream of the reed valve means, the passage means having a port through the cylinder wall in a position below the piston head but at least in large part above the lower edge of the piston when the piston is in bottom dead center position, and said port communicating with said fuel intake chamber and the position of said port being in the region of the axial plane of the wrist pin, and the body of the piston below the piston head having a side wall spaced from the cylinder wall in the region of said port and extending downwardly to the lower edge of the body of the piston to provide a passage between the piston and the cylinder extended downwardly and communicating with the crankcase even when the piston is in bottom dead center position.

Claim 14

An engine as defined in claim 9 and further in which a flow passage is provided in the engine housing structure intercommunicating with the intake chamber and said port.

Claim 15

An engine as defined in claim 10 and including a fuel transfer passage between the crankcase and the cylinder when the piston is in bottom dead center position, and a passage interconnecting the transfer passage with said flow passage.