A scraper is a large piece of equipment used in the mines.The rear part has a vertically moveable hopper (also known as the bowl) with a sharp horizontal front edge. The hopper can be hydraulically lowered and raised. When the hopper is lowered, the front edge cuts into the soil or clay like a plane and fills the hopper. When the hopper is full (8 to 34 m3 or 10 to 44 cu yd heaped, depending on type) it is raised, and closed with a vertical blade (known as the apron). The scraper can transport its load to the fill area where the blade is raised, the back panel of the hopper, or the ejector, is hydraulically pushed forward and the load tumbles out. Then the empty scraper returns to the cut site and repeats the cycle.
On the 'elevating scraper' the bowl is filled by a type of conveyor arrangement fitted with horizontal flights to move the material engaged by the cutting edge into the bowl as the machine moves forward. Elevating scrapers do not require assistance from push-tractors. The pioneer developer of the elevating scraper was Hancock Manufacturing Company of Lubbock, Texas USA. Self-propelled scrapers were invented by R. G. LeTourneau in the 1930s. His company called them Tournahoppers. This concept was further developed by LeTourneau Westinghouse Company. Most current scrapers have two axles, although historically tri-axle configurations were dominant.
Scrapers can be very efficient on short hauls where the cut and fill areas are close together and have sufficient length to fill the hopper. The heavier scraper types have two engines ("tandem powered"), one driving the front wheels, one driving the rear wheels, with engines up to 400 kW (536 hp). Multiple scrapers can work together in a push-pull fashion but this requires a long cut area.
Types of Scraper 
- Single engine open bowl (standard tractor arrangement-usually needs a bulldozer to assist in loading)
- Single engine elevating scraper (using elevator to load material and needs no push tractor)
- Twin engine open bowl (the two engines means usually no push tractor is required)
- Twin engine push-pull (uses all 4 engines by hooking both scrapers together while loading)
- Twin engine auger scraper (uses giant auger mounted vertically in the bowl to pull material upwards)
- Pull type scraper (uses agricultural tractor, articulated dump truck, or bulldozer to pull)
Other brands 
See also 
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