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Hoist atop an elevator. A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium.
Telescoping in mechanics describes the movement of one part sliding out from another, lengthening an object (such as a telescope or the lift arm of an aerial work platform) from its rest state. [1] In modern equipment this can be achieved by a hydraulics , but pulleys are generally used for simpler designs such as extendable ladders and amateur ...
Person on the 1837 man engine at the Samson Pit in Lower Saxony, Germany Bottom of the man engine at the Dolcoath Mine, Cornwall. The earliest known examples of this device were from the first half of the nineteenth century in the silver mining area of the Harz mountains, Germany, where they were driven by cranks connected to water wheels, although bucket hoists ("Hakenkunst") using the same ...
The Roman Polyspaston crane, from Ancient Greek πολύσπαστον (polúspaston, “compound pulley”), when worked by four men at both sides of the winch, could lift 3000 kg. In case the winch was replaced by a treadwheel, the maximum load even doubled to 6000 kg at only half the crew, since the treadwheel possesses a much bigger ...
An extension ladder. A ladder is a vertical or inclined set of rungs or steps commonly used for climbing or descending. There are two types: rigid ladders that are self-supporting or that may be leaned against a vertical surface such as a wall, and rollable ladders, such as those made of rope or aluminium, that may be hung from the top.
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Sailors hauling a halyard. In sailing, a halyard or halliard is a line that is used to hoist a ladder, sail, flag or yard.The term "halyard" derives from the Middle English halier ("rope to haul with"), with the last syllable altered by association with the English unit of measure "yard". [1]
A drum hoist (steel wire rope visible) and motor. In underground mining a hoist or winder [1] is used to raise and lower conveyances within the mine shaft.Modern hoists are normally powered using electric motors, historically with direct current drives utilizing Ward Leonard control machines and later solid-state converters (), however modern large hoists use alternating current drives that ...