Scientific American Supplement No. 819, September 12, 1891

Scientific American Supplement No. 819, September 12, 1891

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Description

Excerpt: ...practical respects from those heretofore proposed, as will appear from the following detailed description of the successive steps in the process illustrated by Figs. 1 to 10. I will distinguish the one pair of diametrically opposite webs of the bar and the notches and mortises punched therein and the links formed therefrom from the other pair by an index figure 1 affixed to the reference letters appertaining thereto. a a are one pair of diametrically opposite webs, and a' a' the other pair of webs of the bar. The first operation illustrated in Fig. 1 is to punch out of the edge of one of the webs, a, a series of shallow notches, b, at equal intervals apart, corresponding to the pitch of the links to be formed out of that pair of webs and situated where the spaces will ultimately be formed between the ends of that series of links. The notches are made with beveled ends, and are no deeper than is absolutely necessary (for the purpose of a guide stop in the subsequent operations, as hereinafter described), so as to avoid, as far as possible, weakening the bar transversely. This operation is repeated upon one of the pairs of webs a'; but whereas in the first operation of notching the web the "pitch" of the notches is determined by the feed mechanism, in this second operation of notching the notches, b, cut in the web, a, serve as guides to influence and compensate for any inaccuracy of the feed mechanism, so that the second set of notches, b', shall be intermediate of and rigorously equidistant from the first set of notches, b. This compensation is effected by the notches, b, fitting on to a beveled stop on the bed of the punching tool by which the notches, b', are cut, the beveled ends of the notches, b, causing the bar under the pressure of the punch to adjust itself in the longitudinal direction (if necessary) sufficiently to rectify any inaccuracy of feed. These notches, b b', similarly serve as guides to insure uniformity of spacing in the...show more

Product details

  • Paperback | 44 pages
  • 189 x 246 x 2mm | 95g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236735781
  • 9781236735782