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.
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