One of these double machines is represented in Plate CCCCLXIX. Fig. 1. The machine receives its motion from an axle, on which there is a pinion which works into the teeth of the wheel C. The sheets of paper lying on the table A are laid by a boy, one by one, on the table B, -dhich has a number of narrow linen tapes extended over its suthce. The action of a lever fixed on the cog wheel of the main cylinder F, gives motion to a lever on the axis of the roller I), which causes the roller C and D to move round part of a revolution, by which motion the sheet of paper is advanced between the rollers h and E, where the two systems of endless tapes meet. When the sheet is thus taken off the table B, the rollers C and D are carried back by a weight W, attached to the cord a, so as to be ready to deliver the next sheet irpo the tapes. The first sheet of viper is now carried along between the systems of tapes to the circumference of the main cylinder F, mounted on a strong axis. and covered with a blanket, and by the revolu tion of this cylinder, the paper is pressed against the form of types lying below F. While one of the sides of the sheet is thus receiving its impression, the other form of types below G is receiving its ink from the inking cylinders. By the motion of the machine, the sheet, one of whose sides was printed by the cylinder F, advances between the tapes and round the cylinders H and I, by which it is inverted and applied in this inverted position to the blanket on the surface of the second cylinder G, by which the other side of the sheet is printed by the form of types below G. The sheet is now at the point i, where the two systems of tapes separate, and it is delivered on the board Z, from which it is removed by a boy.
As the operation of this machine depends upon the sys tem of tapes, it will be necessary to explain their construc tion at greater length. The tapes are so combined, that they always fall either between the pages in the form of types, or near the margin of the sheet of paper. When the paper is therefore taken in between the tapes, it must move along with them till it is brought exactly above the form of types to receive the impression.
If we suppose one system of tapes to begin above the cylinder E, they then follow the under circumference of the roller F; and passing over the upper part of the roller H, and then below the roller I, they surround a considerable portion of the main cylinder G; and after passing along so as to touch the cylinders a, b, c, d, and e, they arrive again at the roller E, from which they started, thus forming an endless system. The second system of tapes beginning at h, pass on to E, where they come into coincidence with the first system, each tape in the one system corresponding to each tape in the other. In this state of coincidence, they advance under F, above H, under I, and round G, separating at the roller i, where they descend to k, and passing in contact with the rollers m, n, o, they return to the roller h. These two systems of tapes revolve without
interfering with each other, and all sliding or displacement of the tapes is prevented by the uniform motion produced by the toothed wheels which connect the cylinders F, G, I, and E. The reciprocating motion of the carriage which holds the forms of types, is produced by a pinion on the upright axis K, which works in the rack LL, connected with the carriage by a system of levers.
The types of each form are inked by two separate inking apparatuses, shown at N and 0. A roller at N, driven by a band from the axis of G, removes slowly a film of ink from a mass of ink on a horizontal plate, nearly in contact with its circumference. An elastic roller 0, which moves round an axis fi, is connected with the axis of G by an ec centric circle, which causes it to rise into contact with N; and after taking a little ink from it, to descend upon the me tallic table 1', fixed to the type carriage, so as to receive ink from 0 during the reciprocating motion of the carriage. The supply of ink on the table T is finely regulated by the elastic rollers II, and it is afterwards taken up by the rollers S, which lay it uniformly upon the types while they pass under these rollers.
Various improvements on printing machines have been lately made by Mr. Augustus Applegath, who has secured the exclusive right to them by patent in 1823. his im provements relate to five points.
1. He passes the distributing ink rollers diagonally instead of directly across the ink table.
2. He makes the ink table, which was formerly metallic, of flexible materials, such as linen, woollen, canvass, carpet ing, leather, Scc. covered with a smooth coating of varnish paint, or the elastic composition of glue and treacle.
3. He inks the form of types by a system of rollers attached to endless chains or bands.
4 He makes the platen or pressing surface in the form of a cylinder, with flattened sides, or of a prism with any num ber of sides.
5. He uses a revolving tympan frame, which carries a number of tympans for the purpose of receiving the sheets of paper, and bringing them successively into the situation where they are to be printed. See Newton's Journal, vol. vii. p. 7.
Another patent for a printing machine was taken out in 1822, by Mr. John Bold, of Bermondsey ; but as it is too complex to be described without the aid of many figures, we must refer the reader to Newton's Journal of the Arts, vol. vi. p. 11, July, 1823, where a drawing and description of it is given.
Church's Type-Founding and Printing Machinery.
The very remarkable apparatus for printing, invented by Mr. William Church, of Birmingham, and secured by patent, in 1822, consists of three machines.