Shaft

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shaft

1. a revolving rod that transmits motion or power: usually used of axial rotation
2. Anatomy
a. the middle part (diaphysis) of a long bone
b. the main portion of any elongated structure or part
3. the middle part of a column or pier, between the base and the capital
4. a column, obelisk, etc., esp one that forms a monument
5. Architect a column that supports a vaulting rib, sometimes one of a set
6. Ornithol the central rib of a feather
7. an archaic or literary word for arrow

Shaft

The main body of a column, pilaster or pier between the capital and the base, or a thin vertical member attached to a wall or pier, often supporting an arch or vaulting rib.

Shaft

 

(in engineering), a rotating machine part (usually mounted in bearings) that transmits a torque moment. The shaft is one of the basic parts of almost all machines and mechanisms. According to their design, a distinction is made among straight shafts (smooth, stepped, or splined camshafts), crankshafts, flexible shafts, and so on.

The most common shafts are the straight stepped shafts, in which the retaining steps prevent axial displacement of the parts located on the shaft, and the transitional steps mark the boundaries of sections with different diameters and tolerances. The design criteria for shafts include strength, stiffness, and resistance to vibration.


Shaft

 

a vertical or inclined mining excavation having an opening from the earth’s surface and designed to open mineral deposits and service underground workings.

A distinction is made between main and auxiliary shafts. The main shaft is located in the central mining area and is principally designed to hoist coal, ore, and other useful minerals to the surface; the auxiliary shaft is used to transport personnel, gangue, equipment, and materials. In addition, the auxiliary shaft can be used for ventilating the shaft and supplying it with fresh air (an intake shaft) or for expelling exhaust; shafts of this kind are located in the central industrial area and on the flanks (flanking shafts) of the mining area. Shafts are equipped with skips, cages, rail or conveyor transportation, and—during the construction stage—buckets.

The upper portion of the shaft has an opening from the earth’s surface called the mouth or collar; the lower portion, below the level of the pit bottom, is called the sump. The shafts usually have a round cross section, although rectangular and, less frequently, elliptic shafts are also found. Vertical shafts can be as much as 9 m in diameter and 3 or 3.5 km deep. Inclined shafts can be rectangular, arched, or round. The shaft walls are reinforced with concrete, reinforced concrete, and metal or reinforced-con-crete tubing; in hard and firm rock, spray concrete is used. The reinforcement of the shaft usually includes metal horizontal components (buntons) and vertical components (conductors) to ensure the smooth operation of skips and cages. Shafts are constructed by blasthole drilling, boring equipment, and shaft-sinking machinery.

A variant of the mine shaft is the blind shaft. A blind shaft is a vertical mining excavation not having a direct opening from the surface and constructed mainly to hoist useful minerals from lower levels of the mine to higher ones.

shaft

[shaft]
(geology)
A passage in a cave that is vertical or nearly vertical.
(mechanical engineering)
A cylindrical piece of metal used to carry rotating machine parts, such as pulleys and gears, to transmit power or motion.
(mining engineering)
An excavation of limited area compared with its depth, made for finding or mining ore or coal, raising water, ore, rock, or coal, hoisting and lowering men and material, or ventilating underground workings; the term is often specifically applied to approximately vertical shafts as distinguished from an incline or an inclined shaft.
(science and technology)
A long, slender, usually cylindrical part.

shaft

shaft in Ionic column, section
1. The portion of a column, colonette, or pilaster between the base and the capital.
2. An enclosed space extending through one or more stories of a building, connecting vertical openings in successive floors, or floors and the roof.
References in classic literature ?
"That will we presently see," quoth Robin, "and meanwhile stand thou where thou art, or else, by the bright brow of Saint AElfrida, I will show thee right good Nottingham play with a clothyard shaft betwixt thy ribs."
"If ye handle yew bow and apple shaft no better than ye do oaken cudgel, I wot ye are not fit to be called yeomen in my country; but if there be any man here that can shoot a better shaft than I, then will I bethink me of joining with you."
There was a terrible expression upon his savage face as he fitted a poisoned shaft to his bow.
Every time he twanged the string of the long bow against his shoulder and heard the gray goose shaft sing, it told him of happy days that he could not recall.
``I will notch his shaft for him, however,'' replied Locksley.
"What do you expect to find first?" asked Tom of Professor Bumper one day, when the latter was at the top of a shaft waiting for a bucket load of dirt to be hoisted up.
Men were hurled in every direction from the ship's deck, while she, bent and crumpled, took the last, long plunge to the scrap-heap at the shaft's base.
Xodar had told me that ascending the shaft by virtue of our repulsive rays alone would give our enemies their best chance to overtake us, since our propellers would be idle and in rising we would be outclassed by many of our pursuers.
Then he bent down and began gnawing the shaft of the arrow with his teeth.
It had almost burned through when I reached the opening into the shaft. I lay down on the edge, for the throb of the great pump below made me giddy.
By this time a whole village was up: and windlasses, ropes, poles, candles, lanterns, all things necessary, were fast collecting and being brought into one place, to be carried to the Old Hell Shaft.
What say you, woodman: wilt leave the bucks to loose a shaft at a nobler mark?"