OF
A FORGING MACHINE,
For Bar Iron, Steel, &c. square or figured.
This Machine acts by pressure instead of percussion. But this pressure is so instantaneous as to resemble a blow, and so often repeated as to produce a considerable effect in a short time. The means are represented in [fig. 4] of [Plate 25].
There, A is a mass of metal answering the purpose of an anvil, but having two surfaces, situated at or nearly at right angles to each other, on which the metal is alternately struck or compressed. The two sides of this mass A, are perforated by two holes, properly bushed, in which turn the crank shafts B, C: the latter furnished with the bevil wheels D, E, which geer into and receive motion from two equal bevil wheels F, G, fixed on the main shaft H I, and to which the power is applied. It is thus evident that the two crank shafts B, C, will make the same number of revolutions; and that if one of the rollers K, L, is placed on the excentric arm of one shaft, and the other roller on the other (their position being as in the [figure]) that then the rollers K L will impinge alternately on any bar, held in the angle M, and forge or extend it, and finally leave it reduced to the same dimensions, in it’s whole length, if, by hand or proper machinery, the bar has been drawn or pushed along the angle M, in a manner analogous to this motion at the tilt hammer. It is also clear, that the size of the bar will be determined on a given Machine, by the diameters of the rollers K L, compared with the distance of the shafts from the angle M of the anvil.
It may be of use to observe, that the effect of this Machine is not confined to square bars: since with unequal rollers K L, it will produce flat bars; and with rollers properly grooved, (the piece M being formed accordingly) it will produce round iron or steel of better texture (I presume) than when taken from the slitting-mill, and merely passed through grooved rollers. I expect, at all events, a rapid effect, from four or five hundred turns of the cranks per minute.
It will occur to every mechanical reader, that the mass M, which is tempered and adjusted to the principal anvil A, may be still more varied in form, so as to give other results besides those above anticipated. Nor need it be said, that the shafts B C might run in steps capable of being screwed up to their work, even during the process, should any such motion be expedient. These are details I do not wish to dwell on in these descriptions—where I endeavour to make known general and essential properties, leaving particular views and cases to my reflecting readers.