instrument for removing dust or dirt from surfaces or for applying paint, whitewash, &c., composed of a tuft or tufts of some fibrous or flexible material secured to a solid basis or stock
Brushes made of the twigs of trees like the birch and provided with long handles are often called brooms, and the same
See also:term is applied to some brushes used in the
See also:house-hold for removing dust (e.g.
See also:broom, whisk-broom) but not to those used for applying paint . Among the numerous materials employed for the manufacture of brushes of various kinds are feathers,
See also:pig's bristles, the hair of certain animals,
See also:rubber, split-
See also:cane, broom-corn (a variety of
See also:sorghum) and coir . Brushes are of two kinds,
See also:simple and compound . The former consist of but one tuft, as hair pencils and painters' tools . The latter have more than one tuft . Brushes with the tufts placed side by side on
See also:flat boards, as plasterers' brushes, are called stock-brushes . The single tuft brushes, or pencils for artists, are made of the hair of the camel,
See also:goat and other animals for the smaller kind, and pig's bristles for the larger . The hairs for pencils are carefully arranged so as to
See also:form a point in the centre, and, when tied together, are passed into the wide end of the
See also:quill or
See also:tube and
See also:drawn out at the other end to the extent required . The small ends of the quills, having been previously moistened, contract as they dry and bind the hair . A similar effect is produced with metal tubes by
See also:compression .
Compound brushes are—first, set or
See also:work; second, drawn-work . Of the former, an example is the.
See also:common house-broom, into the stock of which holes are drilled of the
See also:size wanted . The necessary quantity of bristles, hair, or fibre to fill each hole being collected together, the thick ends are dipped into molten
See also:cement chiefly composed of pitch, bound
See also:round with
See also:thread, dipped again, and then set into a hole of the stock with a
See also:peculiar twisting motion . In drawn-brushes, of which those for shoes, teeth, nails and clothes are examples,: the holes are more neatly bored, and have smaller ones at the top communicating with the back of the
See also:brush, through which a bight or
See also:loop of
See also:wire passes from the back of the stock .
See also:Half the number of hairs of
See also:fibres needed for the tufts to .fill the holes are passed into the bight of the wire, which is then pulled smartly so as to
See also:double the hairs and force them into the loop-hole as far as possible . With all brushes, when the holes have been properly filled, the ends of the fibres outside are cut with
See also:shears, either to an even length or such form as may be desired . The backs are then covered with
See also:veneer or other material to conceal the wire and other crudities of the work . In trepanned brushes the bristles are inserted in holes that do not pass right through the stock, and are secured by threads or wires
See also:running in drawholes which are drilled through the stock at right angles to them . The ends of these drawholes are plugged so as to be as inconspicuous as possible, and the method avoids the
See also:necessity of a veneer on the back . The Woodbury machine, one of the earliest
See also:mechanical devices for the manufacture of brushes, which was invented in
See also:America about 1870, produced brushes of this kind . One of the most important purposes to which brushes have been applied is that of sweeping chimneys, and so far back as 1789
See also:John Elin patented an arrangement of brushes for this purpose . Revolving brushes for sweeping rooms were patented in 181 r, and the first patent in which they were applied to hair-dressing appears in 1862 .
Many inventions for sweeping and cleaning roads by means of revolving brushes and other contrivances have been introduced,one of the first being that ofEdmund Henning in 1699` for " a new engine for sweeping the streets of
See also:London, or any city or
See also:town." Brushes with tufts formed of
See also:steel wire are used for cleaning tubes and flues of steam boilers, for the purpose of removing the scale formed by the products of combustion . Steel-wire brushes are also used for cleaning scale from the interior surfaces of a
See also:boiler, and for removing the sand from the
See also:surface of a casting . Occasionally such brushes are revolved in a machine, for more convenient use on the article to be cleaned or polished . Snyer's patent elastic clutch or coupling, used for such purposes as coupling up or disconnecting a steam-engine from a
See also:line of shafting or dynamo, consists essentially of two disks, the adjacent faces of which are provided, one with a
See also:ring of brushes made of flat steel wire, the other with a number of finely serrated teeth . One of the disks is movable longitudinally on its
See also:shaft, and with the brushes clear of the serrations the clutch is
See also:free . On bringing the disks together, which may be done with the engine running at
See also:speed, the
See also:elasticity of the brush permits the motion to be imparted gradually and without
See also:shock to the
See also:part, until both rotate and are locked together . These clutches are very powerful, and are capable of transmitting as much as 3000
See also:horse-power . In dynamo-electric machinery the
See also:device used to conduct current into or out of the rotating armature is termed a " brush." There are usually two brushes to each dynamo or motor, and they are placed diametrically opposite, lightly touching the commutator of the armature . It is important that there should be
See also:good metallic contact between the brushes and the commutator, and at the same
See also:time the frictional resistance resulting from the contact must be a minimum . To effect this result brushes are variously made . A kind of brush frequently used consists of a number of copper wires laid side by side and soldered together at one end, where the brush is held . Brushes are also made of strips of spongy copper cut like a
See also:comb, which give a number of bearing points on the commutator .
Very good results are obtained from brushes made of copper
See also:wound closely until it takes the exterior form of a rectangular
See also:block, which is held radially in a
See also:spring holder, and bears at the end on the commutator . In place of the gauze block " brushes " of hard
See also:carbon blocks are frequently used (see DYNAMO) .
BRUSA, or BROUSSA (anc. Prusa)
GEORGE DE FOREST BRUSH (1855– )
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