Abstract: A torsional vibration damper is provided which comprises an input element, an output element, a damper hub connected to the output element for rotation therewith and having a plurality of circumferentially spaced, radial hub arms, a drive plate assembly connected to the input element for rotation therewith and having an annular chamber and a plurality of circumferentially equally spaced retaining sections which are formed by narrowed parts of the annular chamber, a plurality of compression springs disposed in the annular chamber and extending between the retaining sections and the hub arms, and a ring member rotatable relative to the input member and output member, disposed within the annular chamber and radially outside the compression springs and having an inner circumferential surface held in contact with radially outer boundaries of the compression springs.

Abstract: A torque transmitting and torsion damping apparatus includes a torsion damper and a friction clutch between a first inertia body and a second inertia body that is supported by said first inertia body for relative rotation. The friction clutch includes a friction plate and a pressure plate that is pressed against the friction disc due to the action of a Belleville spring. The pressure plate has bent-free (straight) projections radially outwardly extending into cutout grooves of the first inertia body. This arrangement allows relative axial movement of the pressure plate to the first inertia body.

Abstract: A torque transmitting and torsion damping apparatus includes a torsion damper and a friction clutch between a first inertia body and a second inertia body that is supported by said first inertia body for relative rotation. The torsion damper include a drive plate assembly for rotation with the first inertia body, a damper hub for rotation with the second inertia body and spring assembly disposed between the drive plate assembly and the damper hub. At radially inward rivet pins and radially outer projections, the drive plate assembly is fixedly attached to the first inertia body, thereby providing split torque transmission from the first inertia body to the drive plate assembly.

Abstract: In a method of controlling a duty-cycle type solenoid valve having a valve body that is driven at a controlled duty ratio and a valve seat on which the valve body rests when the solenoid valve is closed, an additional pulse is applied to the solenoid valve upon a lapse of a predetermined time from an ON/OFF switching point at which a level of a driving pulse is changed to drive the valve body in a direction to close the solenoid valve, so as to reduce the speed of the valve body when resting on the valve seat. The additional pulse has the same phase as the driving pulse applied before the ON/OFF switching point, and has a pulse width that is smaller than that of the driving pulse having the same phase.