. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. e to the melting-house. By these numerous precautions,the blanks or circular discs, when cut out by the next machine, will be very nearly of thesame weight; which they would scarcely be, even if the gauge determined all the platesto the same thickness, because some being more condensed than others, they would weighdifferently under the same volume. A great improvement has been made on that mode of lamination, by the late machine for equalizing the thickness of slips of me
. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. e to the melting-house. By these numerous precautions,the blanks or circular discs, when cut out by the next machine, will be very nearly of thesame weight; which they would scarcely be, even if the gauge determined all the platesto the same thickness, because some being more condensed than others, they would weighdifferently under the same volume. A great improvement has been made on that mode of lamination, by the late machine for equalizing the thickness of slips of metal for making coin, whichhas been for several years introduced into the British mint. A side elevation is shownin^g. 743, and a plan in^^g. 744. It operates in the same way as wire-drawing mechan-isms ; namely, pulls the slips of metal forcibly through an oblong opening, left betweentwo surfaces of hardened steel. The box or case which contains the steel dies, composedof two hardened cylinders, is represented at c in_^g. 743. The pincers employed to holdthe metal, and draw it through, are shown at s r. 743. ;iEaiMil^^ The slips of metal to be operated on by the drawing machine, are first renderedthinner at one end, that they may be introduced between the dies, and also between thejaws of the pincers. This thinning of the ends is effected by another machine, con-sisting of a small pair of rollers, mounted in an iron frame, similar to a upper roller is cylindrical, but the lower is formed with 3 flat sides, leaving merelyportions of the cylinder entire, between these flat sides. The distance between thecentres of the rollers is regulated by screws, furnished with wheels on their upper ends,similar to what is seen in the drawing dies at c. The two rollers have pinions on theiraxes, which make them revolve together; they are set in motion by an endless strappassing round a drum, upon whose axis is a pinion working into the teeth of a wheelfixed upon the axis of the
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Keywords: ., bookcentury1800, bookdecade1840, booksubje, booksubjecttechnology
