twofold purchase
noun Machinery, Mechanics.
a purchase using a double standing block and a double running block so as to give a mechanical advantage of four or five, neglecting friction, depending on whether the hauling is on the standing block or the running block.
Words nearby twofold purchase
two-wheeler,
two-word verb,
twoccing,
twofer,
twofold,
twofold purchase,
twolegged,
twonie,
twoonie,
twopence,
twopenny