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 periodicals archive ?
With regard to the TACs, loss of BMP signaling causes these cells to produce an excess of supportive channel cells at the expense of hair shaft progenitors.
At the proximal end the hair shaft becomes very smooth and decreases in diameter from 5 to 2-3 [micro]m.
Using natural, warmed oils is also a good way to massage the scalp and lock moisture into the hair shaft.
The lice leave eggs, also called nits, attached to the hair shafts.
Buckling is an abrupt change in the shape and orientation of a hair shaft with or without a slight twist, often seen in pubic hairs.
Lice crawl up and down the hair shaft, but cannot jump or fly.
WASHINGTON -- Alopecia has become almost epidemic in black women, the result of certain hairstyles that pull too tightly on the scalp and harsh chemical treatments that damage the hair shaft and follicles, Dr.
WASHINGTON -- Alopecia has become almost epidemic among black women, the result of certain hairstyles that pull too tightly on the scalp and harsh chemical treatments that damage the hair shaft and follicles, Dr.
Try to use intensive conditioners once a week designed to penetrate the hair shaft and replace moisture.
It turns out that all permanent dye must use PPD to adhere to the hair shaft and peroxide to open it.
The beauty of the ionic dryers, according to the players, is while most consumers think of hair dryers as being damaging to their hair, the ionic charges actually work to condition the hair, making the hair shaft more full and smooth and providing a frizz-free finish.
Nits are tiny, yellowish-white oval eggs that are attached at an angle to the hair shaft.