Transactions . expense involvedin the manufacture, practically rules them out of the market. Thereare die-forged eye-bars, so called, which are made by welding anextra piece or pieces on the ends of bars, and hammering into theshape of an eye; but it is needless to say, that these cannot be in-cluded in the category of tcell made eyes. By neither of these processes, however, has it been found possibleto make uniformly, good steel eye-bars; and it has been due to thisfact, perhaps more than any other, that the value of this material,manifestly so much better suited for structural purposes than
Transactions . expense involvedin the manufacture, practically rules them out of the market. Thereare die-forged eye-bars, so called, which are made by welding anextra piece or pieces on the ends of bars, and hammering into theshape of an eye; but it is needless to say, that these cannot be in-cluded in the category of tcell made eyes. By neither of these processes, however, has it been found possibleto make uniformly, good steel eye-bars; and it has been due to thisfact, perhaps more than any other, that the value of this material,manifestly so much better suited for structural purposes than iron,has not yet been fully recognized in bridge construction. The want, above referred to, would seem to have been met by aninvention recently perfected by Mr. Andrew Kloman, of Pittsburgh,by which he is enabled to roll either steel or iron eye-bars directfrom a billet, without upsetting or in any way disturbing the con-tinuity of the material. Section through centre of I Fig: I. Section through centre of hole. The machine by which this result is accomplished is, to speak ingeneral terms, a universal roll train, so arranged that the lower hor-izontal roll can be raised or lowered by hydraulic power applied totoggle-joint connections on the under side of the bearings. The upperroll is moved by screws in the usual way, and by a convenient dis-position of the pitch any required vertical movement can be securedby revolving the gearing a given number of teeth. A METHOD OF EOLLING STEEL OR IRON EYE-BARS, In o])erating the machine, a billet of the required weight to insureproper length of finished bar, is first rolled into the form indicatedin Fig. 4, a squeeze being given at each reversal of the rolls by firstdropping the lower roll, then screwing down the upper one a givenamount, and then forcing the lower roll back into its normal positionin which the arms of the toggle-joints are vertical. When the re-quired dimensions of the body of the bar have been thus obtained,the unfinished
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
