Patent ID: 11859369
Assignee: CATERPILLAR INC.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC E  F | IPC E  F

Claim 18:
19. A method, comprising:
monitoring, by an electronic control module (ECM) of a machine, a state of a prime mover of the machine;
determining, by the ECM, the state of the prime mover;
in response to determining, by the ECM, the state of the prime mover has changed from an engine-off state to an engine-on state:
opening a relief valve coupled to a hydraulic fluid chamber of a torque converter of the machine, the hydraulic fluid chamber housing one or more clutch discs, an input component, and an output component,
relieving hydraulic pressure from hydraulic fluid in the hydraulic fluid chamber, and
biasing, by a mechanical spring, a lockup piston to engage with the one or more clutch discs to couple rotational force from the input component to the output component, the mechanical spring and the lockup piston housed in a piston housing of the torque converter; and

in response to determining, by the ECM, the state of the prime mover has reached a stable state:
closing the relief valve,
allowing the hydraulic pressure from the hydraulic fluid in the hydraulic fluid chamber to build up, and
allowing the lockup piston to be unbiased to disengage from the one or more clutch discs,

wherein the stable state is based, at least in part, on a speed of the prime mover remaining greater than a preselected engine speed for a preselected period of time, the preselected engine speed lower than an idle speed of the prime mover by a preselected amount.