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 ?
Search for the precious map was given up for the time being, and the professor and his friends set the natives to work digging shafts in the ground, as though sinking them down to the level of the buried city.
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.
But in all of them I heard a certain sound: a thud-thud-thud, like the beating of some big engine; and I discovered, from the flaring of my matches, that a steady current of air set down the shafts.
Numbers of those creatures were to be seen basking in the sunshine upon the thatching of the houses, and multitudes at all hours of the day showed their glittering sides as they ran frolicking between the spears of grass or raced in troops up and down the tall shafts of the cocoanut trees.
It was of about the same diameter as the entrance at the foot of the tree, and opened directly upon a large flat limb, the well worn surface of which testified to its long continued use as an avenue for some creature to and from this remarkable shaft.
I did not dare venture an inquiry for fear of arousing suspicion by evident ignorance of something which as a yellow man I should have known; but before we reached the city gate I was to learn the purpose of that grim shaft and the meaning of the mighty accumulation beneath it.
When Robin was a youth of eighteen, stout of sinew and bold of heart, the Sheriff of Nottingham proclaimed a shooting match and offered a prize of a butt of ale to whosoever should shoot the best shaft in Nottinghamshire.
The shaft horse swayed from side to side, moving his ears as if asking: "Isn't it time to begin now?
As I fitted the shaft with my right hand I stopped and wheeled toward the gorilla-man.
It turned back and forth many times, leading, at last, into a small, circular chamber, the gloom of which was relieved by a faint light which found ingress through a tubular shaft several feet in diameter which rose from the center of the room's ceiling, upward to a distance of a hundred feet or more, where it terminated in a stone grating through which Tarzan could see a blue and sun-lit sky.
Feeling up along the sides of the shaft as far as he could reach, the ape-man discovered that so much of the wall as he could feel converged toward the center of the shaft as it rose.
Before him he saw the straight lines of the shafts which constantly deceived him into thinking they were on a well-travelled road, and the horse's swaying crupper with his knotted tail blown to one side, and farther ahead the high shaft-bow and the swaying head and neck of the horse with its waving mane.