CHUWAB'S ROLLING MILL FOR DRESSING AND ROUNDING BAR IRON.

This new forge apparatus has been devised for the purpose of finishing up round irons of all diameters while hot, as they come out of the ordinary rolling mill, by rendering them perfectly circular, cylindrical, straight, smooth, and level at the extremities, as if they had passed through a slide lathe. Such a high degree of external finish is a very valuable feature in those round irons that are employed in so great quantity for shafting, cylindrical axles, etc., as well as in the manufacture of bolts and locks. Figs. 1, 2, 3, and 4 of the opposite engraving will allow it to be seen that this apparatus which is usually installed at the side of the finishing cylinder is, in part, beneath the general level of the forge floor. It may be placed parallel with or perpendicular to the apparatus that it does duty for, this depending upon the site at disposal or the mode of transmission.

The apparatus consists essentially of two tempered iron cylinders, A, 0.5 of a meter in diameter by 1.5 meters in length, revolving in the same direction (contrary to what takes place in ordinary rolling mills) between two frames, B, that are open on one side to allow of the entrance of the finishing bar. This latter is held between the cylinders, A, which roll it so much the faster in proportion as its diameter is smaller, and by a scraper guide, C, of the same length as the cylinder table, and which may be regulated at will by bolts, c, fixed to the frame, B. The bottom cylinder remains always in the same position, while the axle, D, which carries the intermediate wheels, E, moves about to gear in all the relative positions of the cylinders. The displacement of the upper cylinder is effected through the clamping screws, b, which are actuated by toothed disks that gear with two endless screws keyed at the extremities of one shaft in common, d, which is set in motion by hand through the winches, m m. The scraper guards, e e, take up and throw aside all scales that might become attached to the cylinders, which are constantly moistened by small streams of water coming from an ordinary conduit.

CHUWAB'S DRESSING AND ROUNDING ROLLING MILL.
Fig. 1--Elevation and Longitudinal Section.
Fig. 2--Side View.
Fig. 3--Transvers Section.
Fig. 4--Plan View.
Figs. 5 & 6--Saws for Dressing the Extremities of the Bars.
Fig. 7--Diagram Showing the Motion of the Wheels and Guide.
Figs. 8 & 9--Apparatus for Shifting tha Bars.

As the driving belts are mounted on pulleys, G, of a diameter proportioned to the velocity of the shafting, the iron pinions, h, in order to produce 60 revolutions per minute in the first shaft, H, gear on each side with the intermediate wheels, E, and these actuate the two bronze pinions, a a, that are mounted on the extremities of the cylinders, A A. The axle, D, of the intermediate wheels does not revolve with them, but is capable of rising and descending in the elongated aperture that traverses the frames, B. The displacement of this axle is secured through the arms, L L, whose extremities articulate on the one hand with the cylinders, A A, and on the other with D. The result of this is that every displacement upward of the top cylinder corresponds to a different position of the intermediate shaft, and one that is always equidistant from the centers of the cylinders, A A, thus securing a constant gearing of the wheels in all the positions of the cylinders, A A.

The diagram in Fig. 7 shows the relative displacements of all these parts, as well as those of the scraper guide, C. The diameter to be obtained is determined beforehand by the two contact screws, P.

The whole thus regulated, the bar of iron, still very hot, coming from the ordinary rollers, is straightened up, if need be, by a few blows of a hammer, so that it may roll forward over the pavement, N, between the rounding cylinders, A A; these being held apart sufficiently to allow of its easy introduction. Next, a few revolutions of the winches that control the screws suffice to lower the upper cylinder to the exact position limited by the contact screws, P, and the bar is rolled between the two cylinder tables with a constant velocity in the generatrices. As a consequence, the number of revolutions made is so much the greater in proportion as the diameter of the shaft is smaller with respect to that of the cylinders.