The tenacity with which whip cord, cotton cord, and other similar
lines preserve their twist when properly made, is a little remarkable
when considered in relation to the materials from which they are
manufactured, and which as a rule show a tendency when ordinarily
twisted to return to a straight line. This was one of the reflections
which occurred to us when watching a James doubling and laying machine
at work at the late Textile Exhibition, on the stand of Walter T.
Glover & Co., of Manchester. We give a perspective view of this machine.
[Illustration: IMPROVED DOUBLING AND LAYING MACHINE.]
There are several ways of carrying out the process of doubling, which
in its simplest sense consists in laying a given number of folds of
yarn together and putting a twist into them. But beyond this we come to
spindle banding, which is cord, or rope in miniature, and it is made
of three or more ends of the doubled yarn just mentioned, such doubled
yarn becoming, in fact, the strand of a small rope. To lay these
strands properly into a cord they should not only be twisted together,
but each should be twisted separately in the opposite direction to
the twist of the cord. A banding machine, therefore, has to impart
a double twist, and to perform the work perfectly each twist should
be capable of easy regulation; and the drag upon the bobbins should
admit of being adjusted to requirements. These conditions are met in
the James machine, as evidenced by the samples of work produced by it.
As shown in our engraving, the apparatus consists of three heads, of
four spindles each, being capable therefore of doubling a four-strand
cord. The heads work independently of each other, and by throwing one
or two of the spindles out of action a three-strand or a two-strand
cord will be produced. The cord is twisted regularly, and may be made
continuously to any length. The uniformity of the twist depends upon
the fact that the cord is taken up at a regular rate, by a simple and
neat motion, consisting merely of a pair of pulleys, one grooved and
the other with a roughened surface. After leaving these, the cord is
coiled upon the reels seen on the top of the framework. The twist given
to the cord depends upon the rate at which it is taken up, the speed
of the center spindle remaining constant. The twist in the strands is
governed by the speed at which the bobbin spindles revolve. This may
be adjusted as required, by a series of change wheels. An effective
stop motion is also applied to automatically stop the head in which a
breakage takes place, whether of the cord itself or of a single strand.
Either head is started by depressing the handle or knob in front of it.
A feature for which particular merit is claimed is that a heavy drag is
put upon all the strands separately for the purpose of taking out all
the stretch before twisting, which is an important desideratum for the
production of good banding. This is accomplished by hanging weights on
the spindles, which cause the strands to be twisted under tension. The
tension is altered as required by the size and nature of the yarn, by
removing or adding to the weights. The heads being independent of each
other enables the machine to be employed on three cords of different
material and thickness. The production is about 1,300 yards per head
for ten hours, and it is stated that a girl can mind as many as 80 or
90 heads.--_Iron._