power shovel

power shovel
any self-propelled shovel for excavating earth, ore, or coal with a dipper that is powered by a diesel engine or electric motor. Cf. shovel (def. 2).

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      digging and loading machine consisting of a revolving deck with a power plant, driving and controlling mechanisms, sometimes a counterweight, and a front attachment, such as a boom or crane, supporting a handle with a digger at the end. The whole mechanism is mounted on a base platform with tracks or wheels. Power shovels are used principally for excavation and removal of debris.

      Mechanical cable-operated shovels apply engine power to the base and to the attachment by means of clutches, gears, shafts, winch drums, and cable. Electric cable-operated shovels have several electric motors supplied with current by a power line, or more rarely, by a deck-mounted generator, replacing the engine and most of the clutches, gears, and shafts of the mechanical shovel. Hydraulic shovels have engine-driven pumps to provide pressure for rams and motors. Mechanical shovels may include some electrical or hydraulic functions.

      There are five principal types of front attachments, which may be interchangeable in small and medium-sized machines of the cable type. The dipper shovel, the oldest and most important excavating machine (rail-mounted, steam-powered units were in use in 1835), is for hard digging and truck loading. It consists of a heavy, relatively short boom and a dipper stick (a beam that pivots on the boom) with digging bucket attached. The bucket has a hinged bottom that can be opened by the operator. Forward and upward motion fills the bucket. If a long boom is unnecessary and the ground is hard and unyielding, the most suitable excavators are the dipper shovels. The hoe, or backhoe, attachment may replace the boom, stick, and bucket of the dipper shovel for digging below working level; it pulls the load toward the deck of the shovel instead of away from it. Modern hydraulically powered hoes may be mounted on any shovel carrier or on the rear of a tractor. A lifting crane can be attached in place of the digging shovel to raise heavy loads, move them laterally by swinging or travelling, and then lower them into new locations. Specially constructed lifting cranes are designed for hydraulic machines. The dragline excavator has a long boom of lattice design that extends from the cab at an angle of about 35° with the ground. From its end is suspended a hoist cable, at the end of which is the digging bucket. The dragline runs from the cab directly to the bucket; when the bucket is lowered, a pull on the dragline causes it to dig into the earth. The machine then swings the loaded bucket into a disposal area and tips its contents. On soft and watery land, particularly in building power dams, the long reach of the dragline is more effective than bulldozers and other surface-earth removers. The clamshell is a bucket with two hinged jaws carried by a crane suspended from the boom by two lines: one raises and lowers the bucket, and the other pulls the jaws together against gravity for digging action. It is used chiefly for deep, narrow excavations, as in well digging, for piling materials up high, and for rehandling loose material, such as sand or gravel, but it can do almost any type of digging.

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Universalium. 2010.

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Look at other dictionaries:

  • Power shovel — P H 4100 XPB cable loading shovel A power shovel (also stripping shovel or front shovel or electric mining shovel) is a bucket equipped machine, usually electrically powered, used for digging and loading earth or fragmented rock and for mineral… …   Wikipedia

  • power shovel — noun a machine for excavating • Syn: ↑excavator, ↑digger, ↑shovel • Derivationally related forms: ↑shovel (for: ↑shovel), ↑dig (for …   Useful english dictionary

  • power shovel — pow′er shov el n. min civ any self propelled shovel for excavating earth, ore, or coal with a dipper that is powered by a diesel engine or electric motor Compare shovel 2) • Etymology: 1905–10 …   From formal English to slang

  • power shovel — n. power operated machine used for excavating, power excavator …   English contemporary dictionary

  • power shovel — noun Date: 1909 a power operated excavating machine consisting of a boom or crane that supports a lever arm with a large bucket at the end of it …   New Collegiate Dictionary

  • Marion Power Shovel Company — This article is about the company. For the historic Model 91 steam shovel in upstate New York, see Marion Steam Shovel (Le Roy, New York). Marion Power Shovel Company Industry Machinery manufacturing Fate Acquired Successor …   Wikipedia

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  • Shovel (disambiguation) — Shovel may refer too:*Shovel, a tool for lifting and moving loose material *Power shovel, a bucket equipped machine, usually electrically powered, used for digging and loading earth or fragmented rock material, the modern equivalent of steam… …   Wikipedia

  • shovel — I. noun Etymology: Middle English, from Old English scofl; akin to Old High German scūfla shovel, Old English scūfan to thrust away Date: before 12th century 1. a. a hand implement consisting of a broad scoop or a more or less hollowed out blade… …   New Collegiate Dictionary

  • shovel — Synonyms and related words: backhoe, bail, bar spade, bore, bucket, burrow, coal shovel, cup, decant, delve, dig, dig out, dike, dip, dish, dish out, dish up, dredge, drill, drive, excavate, fork, furrow, garden spade, gouge, gouge out, groove,… …   Moby Thesaurus

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