system of u s pat no 4 042 036 the flywheel inertia about its suspension axis 13 fig1 is helpful and augments the clutch operation in this situation the flywheel must accelerate angularly in the opposite direction during the millisecond drive time now large normal forces are exerted on the ram by virtue of the angular acceleration of the flywheel suspension system so that the coefficient of friction between the ram and the flywheel can be even less than tan u03b8 without creating a slip situation the normal force of the flywheel against the ram is increased during the drive this increased force aids in the initial engagement and can provide increased force at a later point in the drive while keeping the engagement normal forces at a minimumm so as to minimize energy losses during engagement similarly in the devices of said copending applications fig2 the inertial force and the spring force both of which work in favor of maintaining driving friction are enhanced by the use of a tapered ram as shown in fig3 as seen in fig4 through 6 and fig7 through 9 the ram taper may be varied in fig4 the taper is stepped in fig5 it is increased rather rapidly on a curve and in fig6 a more complex taper is shown partly positive and partly negative fig4 and 6 illustrate asymmetrical ram tapers the ram taper may be of course symmetrical about the longitudinal axis of the ram as illustrated in fig7 and 9 by varying the taper as suggested in fig4 through 9 it is possible to tailor the.