Abstract: Disclosed is a clutchable pulley system conventionally having an annular first-belt and an annular second-belt, both belts enveloping a plurally-grooved transfer pulley. Also in conventional fashion; the first-belt is constantly tightly trained with a power-source pulley and at least one primary-load pulley; and the second-belt is normally loosely enveloping the plurally-grooved transfer pulley and at lest one secondary-load pulley whereby the secondary-load pulley(s) will not rotate until the second-belt is made to tightly train with the transfer pulley. Departing from the prior art utilization of the idler-pulley principle for controllably tightly entraining the second-belt with the plurally-grooved and secondary-load pulleys, the herein disclosed clutchable pulley system supplants the second-belt idler-pulley by controllably moving the plurally-grooved transfer pulley along an arcuate path.