Abstract: A pneumatic tire, including: a lug groove opening at an end of a ground contact surface of a tread portion and extending toward the tire equatorial plane of the ground contact surface to terminate before reaching the tire equatorial plane; a communication groove making a corresponding pair of the lug grooves located on respective sides of the tire equatorial plane communicate with each other; and at least one widthwise groove, formed in a ground contact surface region demarcated between the end of the ground contact surface and the tire equatorial plane and between one pair and another pair adjacent thereto in the tread circumferential direction of the lug grooves and the communication groove communicating therewith, such that the widthwise groove extends in a direction of a tread width and an end thereof on the outer side in the tread width direction terminates within the ground contact surface region.

Abstract: A pneumatic tire, including: a lug groove opening at an end of a ground contact surface of a tread portion and extending toward the tire equatorial plane of the ground contact surface to terminate before reaching the tire equatorial plane; a communication groove making a corresponding pair of the lug grooves located on respective sides of the tire equatorial plane communicate with each other; and at least one widthwise groove, formed in a ground contact surface region demarcated between the end of the ground contact surface and the tire equatorial plane and between one pair and another pair adjacent thereto in the tread circumferential direction of the lug grooves and the communication groove communicating therewith, such that the widthwise groove extends in a direction of a tread width and an end thereof on the outer side in the tread width direction terminates within the ground contact surface region.

Abstract: A clutch disc consists of a generally annular drive body connectable to an engine side and rotatably movably connected to a generally annular driven body connected to a vehicle drive line. The drive body is formed with a plurality of radially inwardly extending drive side arms. The driven body is formed with a plurality of radially outwardly extending driven side arms. A fluid chamber to be filled with a hydraulic fluid is formed between each drive side arm and each driven side arm. An orifice is formed between the inner periphery of the drive body and the radially outer-most portion of each driven side arm to provide a flow resistance to the fluid flowing between the adjacent fluid chambers, thereby effectively damping torque fluctuation transmitted from the engine side.