Simple machine consisting of a fixed, grooved wheel, sometimes in a block, around which a rope or chain can be run. A simple pulley serves only to change the direction of the applied effort (as in a simple hoist for raising loads). The use of more than one pulley results in a mechanical advantage, so that a given effort can raise a heavier load.
The mechanical advantage depends on the arrangement of the pulleys. For instance, a block and tackle arrangement with three ropes supporting the load will lift it with one-third of the effort needed to lift it directly (if friction is ignored), giving a mechanical advantage of three.
Bairstow Lifting Products Co., Inc. offers a variety of wire rope sheaves from a large line of manufactures to meet OEM replacement specifications. Additionally, we can custom mill a wire rope sheave to you desired measurements, including to OEM specifications, generally faster than one can be obtained by the OEM. Please complete the online .PDF form from the specs tab on the product page and fax or email the form to us. We will return to you promptly with pricing and availability.