Scraper
a stone tool widely used in the Upper Paleolithic, the Mesolithic, and the Neolithic, but occurring also in the Lower Paleolithic and Bronze Age. A scraper was made from a single elongated stone flake, from part of the flake, or from a small flake. The most typical scraper was an end scraper, which had a convex or nearly straight working edge on its narrow end. In oval and rounded scrapers the working edge was continuous or almost continuous around the flake. Scrapers were used for scraping skins, wood, and bone, and often had handles made of wood, bone, or antler.
Scraper
an earth-excavating and transporting machine in which the working element is a scoop that slices off the earth layer by layer and transports and unloads the earth into a pile or spreads the earth out. Scrapers are used in construction work, mainly in leveling operations, and in the mining industry. They are classified according to the type of propulsion (motorized or tractor-drawn), the method of loading or unloading (gravity or mechanical), the parameters of the scoop, the type of drive, and other features.
When loading earth, the scraper moves forward with the scoop lowered. The earth is usually unloaded from the scoop while the machine is moving by spilling it out between the wheels; more rarely, the earth is dumped behind the scraper’s wheels. Scrapers can be used to clear layers of earth up to 0.5 m thick.
The scoop capacities of scrapers manufactured in the USSR range from 3 to 25 m3. Earth is transported over distances of 0.1 to 5 km. Newer scraper designs feature automatic control and scoops that are loaded by means of scraper elevators.
REFERENCES
Dombrovskii, N. G., and M. I. Gal’perin. Zemleroino-transportnye mashiny. Moscow, 1965.See also references under EXCAVATING MACHINES.
L. A. SOKOLENKO
Scraper
a metal-cutting tool in the form of a metal rod with cutting edges on the end, used for scraping. Flat, three-sided, and shaped scrapers differ in the shape of the cutter; scrapers may be designed as one-piece tools, or they may have removable cutting plates. In addition to hand scrapers, pneumatic and electromechanical power scrapers are also used.
In the graphic arts, scrapers are used to remove the burr formed in engraving on metal and to smooth the grainy surface of the metal plate used in mezzotint engraving. They are also sometimes used by lithographers and sculptors.
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