pulley

Definition

One of the simple machines; a sheave, a wheel with a grooved rim, in which a pulled rope or chain lifts an object (more useful when two or more pulleys are used together, as in a block and tackle arrangement, such that a small force moving through a greater distance can exert a larger force through a smaller distance).

Etymology

From Middle English puly, poley, from Old French poulie, polie (“a pulley, windlass”), from Medieval Latin polidia, plural mistaken for the feminine of neuter polidium, from Ancient Greek πολίδιον (polídion, “little pivot”), diminutive of πόλος (pólos, “pivot, hinge, axis”), from Proto-Indo-European *kʷel- (“to turn”). Associated with pull (verb) by folk etymology.

Example Sentences

• "These pulleys […] placed collaterally."
• "Nine hundred of the ſtrongeſt Men were employed to draw up theſe Cords by many Pulleys faſtned on the Poles, and thus, in leſs than three Hours, I was raiſed and flung into the Engine, and there tyed faſt."
• "The steel haulage ropes have a breaking strain of 50 tons, and another pair passing around a pulley at the bottom connect the lower ends of the cars and act as tail or balance ropes."