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In the 1950s, cars were often equipped with curb feelers. [...] Using a piece of 48-inch [120 cm] conveyor belt, 4 to 5 feet [1.2 to 1.5 m] long by 4 to 6 inches [10 to 15 cm] wide and a couple of pieces of angle iron, you can make a pinch-point feeler, a warning device for the corners of a continuous miner. This will give a warning nudge to ...
Bucket-wheel excavators have been used in mining for the past century, with some of the first being manufactured in the 1920s. [1] They are used in conjunction with many other pieces of mining machinery (conveyor belts, spreaders, crushing stations, heap-leach systems, etc.) to move and mine massive amounts of overburden (waste). While the ...
Joy Mining Machinery (Joy) was the world's largest producer of high productivity underground mining machinery for the extraction of coal and other bedded materials including trona and salt. Its products included: Continuous miners – electric, self-propelled digging machines that cut material using carbide-tipped bits on a horizontal rotating ...
If : is a bounded linear operator from a normed space into some TVS then : is necessarily continuous; this is because any open ball centered at the origin in is both a bounded subset (which implies that () is bounded since is a bounded linear map) and a neighborhood of the origin in , so that is thus bounded on this neighborhood of the origin ...
Continuous mining utilizes a continuous miner machine with a large rotating steel drum equipped with tungsten carbide picks that scrape coal from the seam. Operating in a "room and pillar", also known as "bord and pillar" system, where the mine is divided into a series of 20-to-30-foot (5–10 m) "rooms" or work areas cut into the coalbed—it ...
Minimal manning at the face - particularly during the cutting of coal, only one man at a time was allowed at the face (the continuous miner driver) Armoured cabins were built on continuous mining machines - these cabins were thought to be able to protect the operator in the event of an outburst. (This was subsequently proven incorrect.)
Everything remained the same at the mine except for the colors which were changed to red, white, and blue. Like most mining vehicles of extreme size, Marion 6360 only required a surprisingly small amount of men to operate, a total of four consisting of a operator, oiler, welder, and a ground man who looked after the trailing cable. [1]
In fact, the open mapping theorem can in turn be deduced from the closed graph theorem as follows. As noted in Open mapping theorem (functional analysis) § Statement and proof, it is enough to prove the open mapping theorem for a continuous linear operator that is bijective (not just surjective). Let T be such an operator.