US4252092A — Compression release mechanism

Claim 1

Independent Claim 248 words

In an internal combustion engine having a cylinder and piston defining a variable volume combustion chamber, an automatic compression release mechanism comprising a passgeway communicating at one end thereof with the combustion chamber and at the other end thereof with a zone within the engine in which the pressure is lower than the pressure in the combustion chamber during the compression stroke of the piston, a valve chamber having an inlet port and an outlet port serially connecting the chamber in the passageway, a first one-way valve controlling the inlet port and closing the same when valve chamber pressure exceeds combustion chamber pressure, and a second one-way valve operable independently of the first valve controlling the outlet port and tending to close the same when the valve chamber pressure exceeds the pressure in the zone, the second valve being resiliently biased to an open position spaced from the outlet port and movable to a closed position in response to pressure generated in the passageway when a fuel-air mixture is ignited in the combustion chamber, the first and second valves comprising opposed cantilevered ends of a centrally supported flexible plate, both ends being urged to their respective closed positions in response to a pressure build-up in the chamber whereby both of the valves tend to be maintained in a closed position when the engine is running, the valve chamber comprising a pair of valve chamber portions joinable to simultaneously sealingly form the cavity and centrally support the flexible plate.

Claim 2

Dependent Claim 248 words

In an internal combustion engine having a cylinder and piston defining a variable volume combustion chamber, an automatic compression release mechanism comprising a passgeway communicating at one end thereof with the combustion chamber and at the other end thereof with a zone within the engine in which the pressure is lower than the pressure in the combustion chamber during the compression stroke of the piston, a valve chamber having an inlet port and an outlet port serially connecting the chamber in the passageway, a first one-way valve controlling the inlet port and closing the same when valve chamber pressure exceeds combustion chamber pressure, and a second one-way valve operable independently of the first valve controlling the outlet port and tending to close the same when the valve chamber pressure exceeds the pressure in the zone, the second valve being resiliently biased to an open position spaced from the outlet port and movable to a closed position in response to pressure generated in the passageway when a fuel-air mixture is ignited in the combustion chamber, the first and second valves comprising opposed cantilevered ends of a centrally supported flexible plate, both ends being urged to their respective closed positions in response to a pressure build-up in the chamber whereby both of the valves tend to be maintained in a closed position when the engine is running, the valve chamber comprising a pair of valve chamber portions joinable to simultaneously sealingly form the cavity and centrally support the flexible plate.

Claim 3

Dependent Claim 56 words

The compression release mechanism of claim 1 wherein the inlet and outlet ports are both formed in the same valve chamber portion, the other chamber portion including means near each plate end on sides thereof opposite the inlet and outlet ports for limiting movement of the plate ends away from the inlet and outlet ports respectively.

Claim 4

Dependent Claim 263 words

In an internal combustion engine having a cylinder and piston defining a variable volume combustion chamber, an automatic compression release mechanism comprising a passageway communicating at one end thereof with the combustion chamber and at the other end thereof with a zone in the engine in which the pressure is lower than the pressure in the combustion chamber during the compression stroke of the piston, a valve chamber having an inlet port and an outlet port serially connecting the chamber in the passageway, a first one-way valve controlling the inlet port and closing the same when valve chamber pressure exceeds combustion chamber pressure, a second one-way valve operable independently of the first valve controlling the outlet port and tending to close the same when the valve chamber pressure exceeds the pressure in the zone, the second valve being resiliently biased to an open position spaced from the outlet port and movable to a closed position in response to pressure generated in the passageway when a fuel-air mixture is ignited in the combustion chamber, the first and second valves being both urged to their respective closed positions in response to a pressure build-up in the chamber, means for slowly diminishing the chamber pressure to release each valve to return to its respective open position a predetermined time after the engine stops running including a restricted passageway from the chamber to the zone independent of the second valve, continued engine operation maintaining the pressure within the chamber whereby both of the valves tend to be maintained in a closed position when the engine is running.

Claim 5

Dependent Claim 263 words

In an internal combustion engine having a cylinder and piston defining a variable volume combustion chamber, an automatic compression release mechanism comprising a passageway communicating at one end thereof with the combustion chamber and at the other end thereof with a zone in the engine in which the pressure is lower than the pressure in the combustion chamber during the compression stroke of the piston, a valve chamber having an inlet port and an outlet port serially connecting the chamber in the passageway, a first one-way valve controlling the inlet port and closing the same when valve chamber pressure exceeds combustion chamber pressure, a second one-way valve operable independently of the first valve controlling the outlet port and tending to close the same when the valve chamber pressure exceeds the pressure in the zone, the second valve being resiliently biased to an open position spaced from the outlet port and movable to a closed position in response to pressure generated in the passageway when a fuel-air mixture is ignited in the combustion chamber, the first and second valves being both urged to their respective closed positions in response to a pressure build-up in the chamber, means for slowly diminishing the chamber pressure to release each valve to return to its respective open position a predetermined time after the engine stops running including a restricted passageway from the chamber to the zone independent of the second valve, continued engine operation maintaining the pressure within the chamber whereby both of the valves tend to be maintained in a closed position when the engine is running.

Claim 6

Dependent Claim 15 words

The compression release mechanism of claim 3 wherein the zone comprises an engine exhaust conduit.

Claim 7

Dependent Claim 21 words

The compression release mechanism of claim 4 wherein the zone further includes a hollow interior portion of the engine piston pin.

Claim 8

Dependent Claim 238 words

In a two stroke cycle internal combustion engine having a cylinder and piston defining a variable volume combustion chamber with at least a cylinder side wall exhaust port opened and closed by piston movement, an automatic compression release mechanism comprising a passageway including the cylinder side wall exhaust port communicating at one end thereof with the combustion chamber and at the other end thereof with an engine exhaust conduit in which the pressure is lower than the pressure in the combustion chamber during the compression stroke of the piston, a valve chamber having an inlet port and an outlet port serially connecting the chamber in the passageway, a first one-way valve controlling the inlet port and closing the same when valve chamber pressure exceeds combustion chamber pressure, a second one-way valve operable independently of the first valve controlling the outlet port and tending to close the same when the valve chamber pressure exceeds the pressure in the exhaust conduit, the second valve being resiliently biased to an open position spaced from the outlet port and movable to a closed position in response to pressure generated in the passageway when a fuel-air mixture is ignited in the combustion chamber, the first and second valves being both urged to their respective closed positions in response to a pressure build-up in the chamber whereby both of the valves tend to be maintained in a closed position when the engine is running.

Claim 9

Dependent Claim 238 words

In a two stroke cycle internal combustion engine having a cylinder and piston defining a variable volume combustion chamber with at least a cylinder side wall exhaust port opened and closed by piston movement, an automatic compression release mechanism comprising a passageway including the cylinder side wall exhaust port communicating at one end thereof with the combustion chamber and at the other end thereof with an engine exhaust conduit in which the pressure is lower than the pressure in the combustion chamber during the compression stroke of the piston, a valve chamber having an inlet port and an outlet port serially connecting the chamber in the passageway, a first one-way valve controlling the inlet port and closing the same when valve chamber pressure exceeds combustion chamber pressure, a second one-way valve operable independently of the first valve controlling the outlet port and tending to close the same when the valve chamber pressure exceeds the pressure in the exhaust conduit, the second valve being resiliently biased to an open position spaced from the outlet port and movable to a closed position in response to pressure generated in the passageway when a fuel-air mixture is ignited in the combustion chamber, the first and second valves being both urged to their respective closed positions in response to a pressure build-up in the chamber whereby both of the valves tend to be maintained in a closed position when the engine is running.

Claim 10

Dependent Claim 20 words

The compression release mechanism of claim 6 wherein the piston blocks the passageway during a portion of each engine cycle.

Claim 11

Dependent Claim 40 words

The compression release mechanism of claim 7 wherein the portion of the engine cycle during which the passageway is blocked is substantially that portion of the engine cycle during which the combustion chamber communicates with the side wall exhaust port.

Claim 12

Dependent Claim 23 words

The compression release mechanism of claim 6 wherein the first and second valves comprise opposed cantilevered ends of a centrally supported flexible plate.

Claim 13

Dependent Claim 35 words

The compression release mechanism of claim 6 further comprising means for slowly diminishing the chamber pressure to release each valve to return to its respective open position a predetermined time after the engine stops running.

Claim 14

Dependent Claim 32 words

The compression release mechanism of claim 10 wherein the means for diminishing chamber pressure includes a restricted passageway from the chamber independent of the second valve communicating with the exhaust port valve.

Claim 15

Dependent Claim 40 words

The compression release mechanism of claim 6 wherein the passageway communicates with the engine exhaust conduit by way of a piston duct movable with the piston and periodically opening and closing the passageway as the piston moves during engine operation.

Claim 16

Dependent Claim 34 words

The compression release mechanism of claim 12 wherein the piston includes a piston pin for coupling the piston to a connecting rod, the piston duct comprising a hollow channel extending through the piston pin.

Claim 17

Dependent Claim 62 words

The compression release mechanism of claim 12 further comprising means for slowly diminishing the chamber pressure to release each valve to return to its respective open position a predetermined time after the engine stops running including a restricted passageway from the chamber to the end of the piston duct diametrically opposite the side wall exhaust port and independent of the second valve.

Claim 18

Dependent Claim 23 words

The compression release mechanism of claim 6 wherein the first and second valves comprise opposed cantilevered ends of a centrally supported flexible plate.

Claim 19

Dependent Claim 38 words

The compression release mechanism of claim 15 further comprising means near each plate end on sides thereof opposite the inlet and outlet ports for limiting movement of the plate ends away from the inlet and outlet ports respectively.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1984-02-24	1984-08-25	1985-02-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1988-02-24	1988-08-25	1989-02-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1992-02-24	1992-08-25	1993-02-24	$7700.00	Window Closed / Lapsed

Compression release mechanism

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