In the year 1800, however, a decided step forward was made by the production of an iron press, invented by the then Earl Stanhope. This was not only stronger and more durable, by reason of the material used in its construction, but a much larger forme could be impressed at a time, the platen, being made considerably larger than in the old presses.
In all presses, as has been seen, it is necessary to have a flat table, called a type-bed or bed, on which the forme rests, and the flat plane or platen which gives the impression.
But if the platen were always over the type forme, the inking of the latter and the laying on of the paper would be matters of great difficulty. Hence provision was made, even in the early presses, for withdrawing the bed from under the platen after each impression, thus leaving the type free to be inked and to receive the paper. In the Stanhope and all other modern handÂprinting presses, the bed is mounted on an iron carriage, which is run in and out on rails or runners by means of a handle, and an endless band. When the handle is turned one way the carriage moves towards the platen, and passes under it until it reaches the position in which the type should receive the impression. When the handle is turned the reverse way the carriage recedes, and goes to the far end of the rails or runners.
Again it is very desirable to have some arrangement whereby the sheet may be very accurately laid on the type. For this purpose a kind of leaf or flap is hinged to one end of the bed, and the paper is fixed upon it to certain marks when it is in an upright position. It is then turned down, and the paper comes upon the type in the exact position in which it is wanted.
This arrangement is called a tympan, a name acquired from its being like the top of a drum (tympanum). It consists of a thin frame of metal, over which parchment or cloth is stretched. The paper to be printed is laid upon this, and the bottom side of the tympan being jointed or hinged to the bed of the press, it is only necessary to turn it down, in order to bring the paper in contact with the type.
In the annexed illustration of the Stanhope Press, A is the plane or “platen,” which rises and falls, but always remains parallel to the parts that come beneath it. The plane or ” bed,” on whioh the type is laid, is marked B. The tympan is marked G. The sheet of paper is laid on the side of C facing the platen, and the tympan is turned down flat on B. The latter then travels on the two rails until it comes under A, and there the forme receives the impression. After this the carriage is withÂdrawn, the tympan lifted, and the sheet removed.
In the illustration is another flap, D, hinged upon the tympan. This is called the fiisket, and its uses are chiefly to hold the sheet and prevent it from falling, and to prevent the margins of the paper being soiled, as will be explained hereafter. After the sheet has been placed upon the tympan, C, the frisket is folded down upon it, and both together are folded down upon the type forme.
This arrangement of platen, carriage, bed, tympan, and frisket is the same in all the hand presses; the only difference between them lies in the mode in which the power is acquired for bringing down the platen.
It needs hardly to be said that the larger the forme is the larger the platen must be, and in proportion as these are large so must the power be for giving the impression. It will obviously be easier to take an impression of a square inch of type than one of a forme measuring a square yard. For this reason platens in the old days were small, and when the forme was large part only at a time was brought under the platen; and hence, inasmuch as many formes required two pulls, the press was often called a ” two-pull press.”
The Stanhope Press.-Lord Stanhope, however, not only so strengthened the platen, by ribbing it as shown in the illustration, but, by devising a system of levers, enabled a man with one pull to give a sufficient impression to a forme of considerable size.
The arrangement of these levers is shown in Fig. 2 and Fig. 3, but in the press itself they are placed horizontally. The handle, instead of being hinged in the centre of the press, moves on a pivot close to the pressman. At the outer edge or staple of the press is an upright pillar or arbour, its lower end resting on a. pivot, its upper being held by a top plate through which it passes. The handle then acts through the series of levers on the screw„ and on the platen attached to it. When the latter is raised, the arrangement is as in Fig. 2. But when the pressman has pulled the handle into the position shown in Fig. 3, the platen is-depressed and presses the forme.
By this arrangement the levers are, at the time of impressing the sheet, in the position when most power is given out, and when most power is wanted. In the descent of the platen, at first merely motion is required; after that, power. The old presses which the Stanhope superseded were screwed up and down, with equal velocity and power throughout all parts of their travel. With the Stanhope press about 200 impressions can be taken in an hour.
From the 1892 Edition of Practical Printing by John Southward