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122. INGRAM, HERBERT, 198 Strand — Proprietor.
A printing machine, on the vertical principle, as used at the "Times" office.
The chief advantage of this new arrangement is, that the whole motion or circuit of the type can be made available for printing, whereas, in the flat machine, more than half the motion of the reciprocating type table is lost: and the reason for placing the cylinder in a vertical position is to obtain more easy access to the type, inking rollers, and other parts of the machine, and to permit more impressing cylinders to be arranged around the type drum than can be done when it is fixed horizontally.
The circumference of the central drum, or path of the type, is exactly 200 inches; in the machines at the "Times Office" eight impressing cylinders surround the type, which therefore print eight sheets at every revolution; but in those machines the type is not truly cylindric, but is segmental, which involves the necessity of using large cylinders, but when the type is purely cylindric smaller impression rollers may be used, and the produce very much increased.
The machine which is erected in the Exhibition is made to print circular woodcuts and type in the best manner. Each of the four impressing cylinders has 50 inches space for itself and its attendant inking rollers, and the form has the advantage of receiving its ink or colour from several rollers, each of which is well distributed or evenly covered with ink.
The vertical position of the inking rollers also conduces greatly to the production of good work; for the type or engraving is only touched on its extreme surface, while, on the flat principle, where the inking rollers act by gravity, the sides of the type are liable to receive colour. Another advantage is, that any dust in the paper is shaken out by the act of stopping, and falls upon the floor in place of being deposited upon the inking rollers and distributing table as in the flat machine: this is in practice a real advantage, for 50,000 impressions have been taken without once stopping to brush out the form or table. Another technical advantage in the printing of wood engravings, where delicate overlaying is required, is that the impressing cylinders are in direct connection with the type drum, so that no irregularity of motion can occur, and the overlays can be placed precisely where required without any fear of derangement.
Attention is also directed to the superior smoothness of the action of the vertical machine, as compared with the heavy blows produced in a flat or reciprocating machine at each change of motion in the ponderous type table and its appendages.
The action of the machine is very simple, the "layer on" draws a sheet of paper towards a small roller in rapid motion, which descends and causes the paper to enter between the vertical tapes which carry it downwards, when, having arrived at the proper position, it is suddenly stopped by narrow upright strips of wood, which advance and slightly compress the sheet between them, the vertical tapes at the same moment releasing it;—the stoppers are then in their turn withdrawn, leaving the sheet of paper momentarily suspended by two small pulleys, mounted on delicate springs called finger rollers. The sets of vertical rollers seen in rapid motion on each side of the sheet now advance against it, and impel it sideways towards the impressing cylinder, where it receives the impression from the type; the sheet continues its side motion, supported only by a single pair of tapes, which at the proper place are stopped, leaving the printed sheet suspended until the "taker off" draws it down upon the taking-off table.
The diagram on the preceding page will explain the action of the machine employed for the "Times;" h, h, h, represent the position of the laying-on tables.
The chases which hold the type are made with circular beds, and are securely fixed to the iron rings of the type drum. The column rules are converted by means of screws into tension bars, and they bind the sides of the chase or type-holder together, so that each column can be set up by means of a screw at its foot to any required degree of pressure. The inking rollers, which are seen in a vertical position between the impressing cylinders, are caused to press against the type and distributing table by long coiled springs, adjusted to a proper tension; they receive the ink from a circular distributing surface placed opposite to the type, and which, during its revolution, rises up and down by travelling upon an undulating railway. The ink is deposited upon the distributing table by a roller which occasionally vibrates against the ductor roller of the ink-box.
The wheels which connect the type drum and the impressing cylinders are beneath the machine, motion is communicated to the ink-box by the upper bevil wheel seen on the spindle of the type drum, and to the feeders by the lower bevil wheel.
The vertical principle admits of great variety of construction, and is equally applicable to perfecting machines for book work.