Patent attributes
A spring preloaded lockup clutch system comprises clutch disc(s), an input component, and an output component housed in a hydraulic fluid chamber of a torque converter, a lockup piston and a mechanical spring housed in a piston housing of the torque converter, and a relief valve coupled to the hydraulic fluid chamber. The clutch disc(s), when engaged, couples the input component to the output component. The lockup piston has a first end and a second end, engages with the clutch disc(s) when biased, and disengages from the clutch disc(s) when unbiased. The mechanical spring, coupled to the lockup piston at the second end, applies force to bias the lockup piston. The relief valve, when opened, relieves hydraulic pressure in the hydraulic fluid chamber allowing the lockup piston to remain being biased, and, when closed, allows the hydraulic pressure to build up allowing the lockup piston to be unbiased.