Multiple lockup clutch and torque converter with the same clutch incorporated therein

Abstract

A multiplate lockup clutch for use in fluid, principally in a torque converter is provided with a multiplicity of friction plates. Each of the friction plates is provided on a friction surface thereof with at least one combined groove, preferably, a plurality of combined grooves. Each combined groove consists of a first groove and a second groove. The first groove extends from an inner circumferential edge to an outer circumferential edge of the friction plate and communicates an inner circumference and an outer circumference of the friction plate with each other. The second groove intersects the first groove and extends in a circumferential direction of the friction plate. As an alternative, a multiplate lockup clutch useful in fluid, primarily in a torque converter is provided with a multiplicity of friction plates, and each of the friction plates is shaped in a waveform as viewed in a circumferential direction thereof.

Dependencies are inferred from the claim text.