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TYPEWRITER

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Originally appearing in Volume V27, Page 503 of the 1911 Encyclopedia Britannica.
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TYPEWRITER  , a See also:

writing See also:machine which produces characters resembling those of See also:ordinary letterpress; the See also:term is also applied to the operator who See also:works such See also:machines . In 1714 a See also:British patent was granted to See also:Henry See also:Mill, who claimed that he had brought his invention to perfection at See also:great pains and expense, for " An Artificial Machine or Method for the Impressing or Transcribing Letters, Singly or Progressively one after another as in Writing, whereby all Writing whatever may be Engrossed in See also:Paper or See also:Parchment so Neat and Exact as not to be distinguished from See also:Print "; but beyond the See also:title the patent gives no indication of the nature or construction of the machine . In See also:America a patent for a " typographer " was obtained by See also:William A . Burt in 1829, but the records of it were destroyed by a See also:fire at See also:Washington in 1836 . The " typo-graphic machine or See also:pen " patented by X . Progrin, of See also:Marseilles, in 1833, was on the type-See also:bar principle, and at the See also:York See also:meeting of the British Association in 1844 a Mr Littledale showed an apparatus for the use of the See also:blind, by which the impression of a type selected from a See also:series contained in a slide could be embossed on a See also:sheet of paper . In the " chirographer," for which See also:American See also:patents were granted to See also:Charles Thurber in 1843 and 1845, a See also:horizontal See also:wheel carried in its periphery a series of rods each bearing a See also:letter, the wheel being rotated till the required type was over the See also:printing point . The Great See also:Exhibition of 1851 contained a machine patented by See also:Pierre See also:Foucault, of See also:Paris, in 1849, in which a series of rods with type at their ends could be pushed down to emboss paper at the printing point to which they were arranged radially; and there was in addition the " typograph " of William See also:Hughes, which was also intended for See also:embossing, though it was subsequently modified to give an impression through See also:carbon paper . Between 1847 and 1856 See also:Alfred E . See also:Beach in America, and between 1855 and 186o See also:Sir Charles See also:Wheatstone in See also:England, constructed several typewriters, and in 1857 Dr S . W . See also:Francis, of New York, made one with a See also:pianoforte See also:keyboard and type bars arranged in a circle .

In 1866 See also:

John See also:Pratt, an American living in See also:London, patented a machine having 36 types mounted in three rows on a type wheel, the rotation of which brought the required See also:character opposite the printing point, when the paper with a carbon sheet intervening was pressed against it by a See also:hammer worked by the keys . Two years later an American patent was taken out by C . L . Sholes and C . Glidden, and in 1875, after effecting various improvements, they finally placed the manufacture of their machines in the hands of Messrs E . See also:Remington & Sons, See also:gun-makers, of See also:Ilion, New York . The Remington machines worked on the type-bar principle, but at first each of the 44 bars carried only a single character, so that the writing was in capitals only . But in 1878 type-bars with two types were introduced, so that a machine with 40 keys, two being See also:change-See also:case keys, could print 76 characters, with both See also:capital and small letters . The great See also:majority of See also:modern typewriters are worked from a keyboard; the few that are not, known as See also:index machines, will be disregarded here, for although they are much less expensive in first cost than the others, they scarcely come into competition as See also:practical See also:instruments, on See also:account of their slowness . See also:Key-See also:board machines fall into two classes, according as the types which make the impressions are (a) carried at the end of levers or type-bars which strike the paper when the keys are depressed, or (b) are arranged See also:round the circumference of a wheel, or segment, which is rotated by the See also:action of the keys until the corresponding type is brought opposite the printing point . The former of these arrangements is the more See also:common . Another point of difference is in the inking See also:device; in some cases, the type is inked by means of an See also:ink-See also:pad before being brought down on the paper to make the impression, but more frequently an inked ribbon is See also:drawn along by the action of the machine between the type-See also:face and the paper .

Sometimes this ribbon is inked in two See also:

colours, enabling the operator, by bringing the appropriate portion opposite the type-face, to write, say, in See also:black and red at will . A third basis of See also:classification may be found in the arrangement of the keyboard . In some machines there is one key for each character, in others each key does See also:duty 502 for two or more characters . For example, in the former class there is one key for the capital A and another for the small a, the keys being arranged in two See also:banks corresponding to the upper and See also:lower cases of a printer's type-case; in the latter, one key is capable of striking both the small and the capital letter, and it does one or other according as a subsidiary key is or is not brought into simultaneous use with it . In type-bar machines designed on this See also:plan, each bar carries two or more letters (cf. fig . 1) . This See also:form of keyboard is also applied to type-wheel machines . Though there are numberless See also:differences in detail, all type- writers, apart from the index machines, See also:bear a See also:general resem- blance to each other in their me- chanical arrangements . The really essential operations may be reduced to two; the machine must print a letter when a key is struck, and it must have a device by which the paper may be moved a See also:short distance to the See also:left with each stroke in See also:order that the letters may be printed separately, not one on See also:top of the other . Of the many subsidiary appliances that are fitted —a See also:bell to warn the operator that he is approaching the end of a See also:line, a See also:lock to prevent the machine from working after the end of the line has been passed, attachments for facilitating insertion of fresh paper, corrections, and tabulation, &c.—some are certainly of advan- tage, but others are more useful to the manufacturer in See also:drawing up his advertisements than to the See also:expert operator, whose first care often is to disconnect them from " visible writing," which is some- times put forward as a recommendation of extraordinary importance; doubtless the novice who is learning the keyboard finds a natural See also:satisfaction in being able to see at a glance that he has struck the key he was aiming at, but to the practised operator it is not a See also:matter of great moment whether the writing is always in view or whether it is only to be seen by moving the See also:carriage, for he should as little need to test the accuracy of his performance by See also:constant inspec- tion as the piano-player needs to look at the notes to discover whether he has struck the right ones . The one important desid- eratum, without which no type- writer can produce See also:work of satisfactory See also:appearance, is ac- curacy of See also:alignment . For the attainment of this the use of type-bars has given wide See also:scope to the ingenuity of inventors, who have been confronted with the problem of making a See also:system of levers at once strong, rigid Machine. them on See also:bearings which are steady and adjustable for See also:wear in conditions where space is much restricted .

Phoenix-squares

In the See also:

Oliver machine the type-bar is of the form shown in fig. r, to secure stiffness and a See also:double bearing . In the Bar-Lock, the type-bars are arranged three in one hanger, so that each has a bearingthree times as wide as would be possible in the same space if each had a hanger to itself (fig . 2) ; in addition the wear of the pivots can be taken up by the screws seen on the right of the bearings, and as a further P precaution each type-bar is locked at the printing point by falling between a pair of conical pins, which centre it exactly in the required See also:place . In the Yost and the See also:Empire the type-bars pass through guides . The centre See also:guide of the former is shown at G in fig . 3, the type being just about to strike the paper . Pressure on one of the keys works the See also:lever and pushes up the FIG . 3 — Central connecting-See also:rod C, when the type leaves Guide and Type-bar of the ink-pad P and passes through the Yost Machine . guide, which is slightly bevelled so as to guide it exactly to the printing point . In the See also:Smith Premier the shafts upon which the type- bars See also:swing are mounted tangentially on the See also:ring (fig . 4), so that See also:long supporting bearings are obtained, while the shortness of the type-bars themselves renders it possible to make them very stiff . The rocking-See also:shaft mechan- ism a (fig .

5), by which the See also:

power is transmitted from the keys to the type-bars, admits of each key having the same leverage and tends to uniformity of See also:touch . This last quality is also aimed at by inter-posing an intermediate parallel bar between the key levers and the type-bar, as in the New See also:Century Caligraph . In the See also:Dens-more the See also:friction of the movements is minimized by the employment of See also:ball bearings for the type-bar pivots . See also:Electrical type-writers, in which the depression of a key does not 1 work a type-bar directly, but merely closes a See also:circuit that energizes an electro- magnet, have been sug- FIG, 5.-Rocking-shaft Mechanism of gested as a means of Smith Premier . obtaining uniformity of I, Key with See also:stem . 2, Rocking shaft . touch combined with ease 3, Connectingrod . 4 . TYPe;bar, and rapidity, but have not as yet displaced the A and B, Conical bearings, If, in. apart. ordinary machines to any extent . One See also:special form of typewriter, the See also:Elliott-See also:Fisher, is designed to write in a See also:book such as a See also:ledger . One See also:leaf is clamped between the platen and an open See also:frame which holds the paper smoothly . The operative parts slide on this frame, and move up and down the See also:page so as to space the lines properly, the keyboard, with the type-bars, ribbon, &c., travelling step by step across the page .

An adding device may be combined with this machine . Machine .

End of Article: TYPEWRITER
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