Systems and methods for selectively disengaging a clutch to protect engines from damage

A device for use with a vehicle including a clutch, a transmission, a slave cylinder, and a master cylinder, the device for selectively disengaging the clutch from the transmission, comprising:

• a primary piston configured to urge hydraulic fluid into the slave cylinder, when the primary piston is moved from a first position to a second position, to thereby disengage the clutch from the transmission;
• wherein the primary piston is normally movable from the first position to the second position by hydraulic actuation of the master cylinder;
• and
• a secondary piston configured to selectively apply force to the primary piston, to move the primary piston from the first position to the second position, when the secondary piston is selectively actuated independent of hydraulic actuation of the master cylinder;
• wherein the secondary piston is configured such that the secondary piston does not move when the primary piston moves from the first position to the second position by hydraulic actuation of the master cylinder;
• and
• wherein the secondary piston is selectively actuated by a solenoid.

A method for use with a vehicle including a clutch, a transmission, a slave cylinder, a master cylinder, an engine, and a disengagement device, wherein the disengagement device includes a primary piston and a secondary piston, the method for selectively disengaging the clutch from the transmission, the method comprising:

• (a) monitoring for a triggering condition that relates to a rotation rate of the engine;
• (b) when the triggering condition being monitored for at step (a) is not detected, selectively urging hydraulic fluid into the slave cylinder to disengage the clutch from the transmission in dependence on an action of the master cylinder moving the primary piston, without moving the secondary piston;
• and
• (c) when the triggering condition being monitored for at step (a) is detected, moving the secondary piston to apply force to the primary piston and thereby urging hydraulic fluid into the slave cylinder to disengage the clutch from the transmission independent of an action of the master cylinder;
• wherein the triggering condition being monitored for at step (a) is detected when at least one of the following events is detected
• (a1) a metric indicative of a rotation rate of the engine exceeds a first threshold;
• (a2) the metric indicative of the rotation rate of the engine exceeds the first threshold for at least a specified period of time
• (a3) a metric indicative of a rate of change of the rotation rate of the engine exceeds a second threshold;
• or
• (a4) the metric indicative of the rate of change of the rotation rate of the engine exceeds the second threshold for at least a specified period of time.

A device for use with a vehicle including an engine, a clutch, a transmission, a slave cylinder, and a master cylinder, the device for selectively disengaging the clutch from the transmission, and the device comprising:

• a primary cylinder including
• a first opening hydraulically connectable with the master cylinder,
• a second opening hydraulically connectable with the slave cylinder, and
• a primary piston arranged between the first opening and the second opening and biased toward the first opening;
• a secondary cylinder including
• an inlet adapted to selectively receive a secondary fluid,
• a secondary piston biased toward the inlet, and
• a shaft connected with the secondary piston;
• and
• an aperture extending between the secondary cylinder and the primary cylinder;
• wherein the shaft connected with the secondary piston is received at least partially within the aperture and a seal is formed between the shaft and the aperture such that the primary cylinder is substantially isolated from the secondary cylinder;
• wherein the shaft is not connected with the primary piston;
• wherein the clutch is disengageable from the transmission when fluid is urged from the primary cylinder to the slave cylinder by moving the primary piston toward the second opening;
• and
• wherein the primary piston is movable toward the second opening by urging fluid from the master cylinder into the primary cylinder at the first opening of the primary cylinder and/or introducing the secondary fluid into the secondary cylinder at the inlet to move the secondary piston toward the aperture so that the shaft moves through the aperture and contacts the primary piston.

A device for use with a vehicle including an engine, a clutch, a transmission, a slave cylinder, and a master cylinder, the device for selectively disengaging the clutch from the transmission, and the device comprising:

• a primary cylinder including
• a first opening hydraulically connectable with the master cylinder,
• a second opening hydraulically connectable with the slave cylinder, and
• a primary piston arranged between the first opening and the second opening and biased toward the first opening;
• a secondary cylinder including
• an inlet adapted to selectively receive a secondary fluid,
• a secondary piston biased toward the inlet, and
• a shaft connected with the secondary piston;
• an aperture extending between the secondary cylinder and the primary cylinder;
• and
• a stop connectable with the primary cylinder and adjustable to limit the travel distance of the primary piston;
• wherein the shaft connected with the secondary piston is received at least partially within the aperture and a seal is formed between the shaft and the aperture such that the primary cylinder is substantially isolated from the secondary cylinder;
• wherein the clutch is disengageable from the transmission when fluid is urged from the primary cylinder to the slave cylinder by moving the primary piston toward the second opening;
• wherein the primary piston is movable toward the second opening by urging fluid from the master cylinder into the primary cylinder at the first opening of the primary cylinder and/or introducing the secondary fluid into the secondary cylinder at the inlet to move the secondary piston toward the aperture so that the shaft moves through the aperture and contacts the primary piston;
• and
• wherein the stop comprises one of
• a cap having internal threads mateable and advanceable along external threads of the primary cylinder, or
• a screw having external threads mateable and advanceable along internal threads of the primary cylinder.

A device for use with a vehicle including an engine, a clutch, a transmission, a slave cylinder, and a master cylinder, the device for selectively disengaging the clutch from the transmission, and the device comprising:

• a primary cylinder including
• a first opening hydraulically connectable with the master cylinder,
• a second opening hydraulically connectable with the slave cylinder, and
• a primary piston arranged between the first opening and the second opening and biased toward the first opening;
• a secondary cylinder including
• an inlet adapted to selectively receive a secondary fluid,
• a secondary piston biased toward the inlet, and
• a shaft connected with the secondary piston;
• and
• an aperture extending between the secondary cylinder and the primary cylinder;
• wherein the shaft connected with the secondary piston is received at least partially within the aperture and a seal is formed between the shaft and the aperture such that the primary cylinder is substantially isolated from the secondary cylinder;
• wherein the clutch is disengageable from the transmission when fluid is urged from the primary cylinder to the slave cylinder by moving the primary piston toward the second opening;
• wherein the primary piston is movable toward the second opening by urging fluid from the master cylinder into the primary cylinder at the first opening of the primary cylinder and/or introducing the secondary fluid into the secondary cylinder at the inlet to move the secondary piston toward the aperture so that the shaft moves through the aperture and contacts the primary piston;
• and
• wherein the primary piston is biased toward the inlet by a first spring;
• and
• wherein the secondary piston is biased toward the inlet by a second spring.

A device for use with a vehicle including an engine, a clutch, a transmission, a slave cylinder, and a master cylinder, the device for selectively disengaging the clutch from the transmission, and the device comprising:

• a primary cylinder including
• a first opening hydraulically connectable with the master cylinder,
• a second opening hydraulically connectable with the slave cylinder, and
• a primary piston arranged between the first opening and the second opening and biased toward the first opening;
• a secondary cylinder including
• an inlet adapted to selectively receive a secondary fluid,
• a secondary piston biased toward the inlet, and
• a shaft connected with the secondary piston;
• and
• an aperture extending between the secondary cylinder and the primary cylinder;
• wherein the shaft connected with the secondary piston is received at least partially within the aperture and a seal is formed between the shaft and the aperture such that the primary cylinder is substantially isolated from the secondary cylinder;
• wherein the clutch is disengageable from the transmission when fluid is urged from the primary cylinder to the slave cylinder by moving the primary piston toward the second opening;
• wherein the primary piston is movable toward the second opening by urging fluid from the master cylinder into the primary cylinder at the first opening of the primary cylinder and/or introducing the secondary fluid into the secondary cylinder at the inlet to move the secondary piston toward the aperture so that the shaft moves through the aperture and contacts the primary piston;
• wherein the primary cylinder further includes a third opening between a fully biased position of the primary piston and the second opening;
• and
• wherein the third opening is hydraulically connectable with a fluid reservoir.

A device for use with a vehicle including an engine, a clutch, a transmission, a slave cylinder, and a master cylinder, the device for selectively disengaging the clutch from the transmission, and the device comprising:

• a primary cylinder including
• a first opening hydraulically connectable with the master cylinder,
• a second opening hydraulically connectable with the slave cylinder, and
• a primary piston arranged between the first opening and the second opening and biased toward the first opening;
• a secondary cylinder including
• an inlet adapted to selectively receive a secondary fluid,
• a secondary piston biased toward the inlet, and
• a shaft connected with the secondary piston;
• and
• an aperture extending between the secondary cylinder and the primary cylinder;
• wherein the shaft connected with the secondary piston is received at least partially within the aperture and a seal is formed between the shaft and the aperture such that the primary cylinder is substantially isolated from the secondary cylinder;
• wherein the clutch is disengageable from the transmission when fluid is urged from the primary cylinder to the slave cylinder by moving the primary piston toward the second opening;
• wherein the primary piston is movable toward the second opening by urging fluid from the master cylinder into the primary cylinder at the first opening of the primary cylinder and/or introducing the secondary fluid into the secondary cylinder at the inlet to move the secondary piston toward the aperture so that the shaft moves through the aperture and contacts the primary piston;
• wherein the secondary cylinder further includes a vent within a wall of the secondary cylinder between the secondary piston and the aperture;
• and
• wherein the vent allows venting of the secondary cylinder to an environment when the secondary piston is moved toward the aperture.

A device for use with a vehicle including a clutch, a transmission, a slave cylinder, and a master cylinder, the device for selectively disengaging the clutch from the transmission, comprising:

• a primary piston configured to urge hydraulic fluid into the slave cylinder, when the primary piston is moved from a first position to a second position, to thereby disengage the clutch from the transmission;
• wherein the primary piston is normally movable from the first position to the second position by hydraulic actuation of the master cylinder;
• and
• a secondary piston configured to selectively apply force to the primary piston, to move the primary piston from the first position to the second position, when the secondary piston is selectively actuated independent of hydraulic actuation of the master cylinder;
• wherein the secondary piston is configured such that the secondary piston does not move when the primary piston moves from the first position to the second position by hydraulic actuation of the master cylinder;
• and
• a shaft connected with the secondary piston, unconnected with the primary piston, and including first and second ends;
• wherein the first end of the shaft is connected with the secondary piston;
• and
• wherein the second end of the shaft selectively contacts the primary piston thereby enabling the secondary piston to selectively apply force to the primary piston.