The force with which the shuttle is thrown in an ordinary power
loom moving with a certain speed is always considerable, and, as a
consequence of the strain exerted on the thread, it is frequently
necessary to use a woof stronger than is desirable, in order that it may
have sufficient resistance. On another hand, when the woof must be very
fine and delicate the fabric is often advantageously woven on a hand
loom. In order to facilitate the manufacture of like tissues on the
power loom the celebrated Swiss manufacturer, Hanneger, has invented an
apparatus in which the shuttle is not thrown, but passed from one side
to the other by means of hooks, by a process analogous to weaving silk
by hand. A loom built on this principle was shown at work weaving silk
at the Paris Exhibition of 1878. This apparatus, represented in
the annexed figure, contains some arrangements which are new and
interesting. On each side of the woof in the heddle there is a carrier,
B. These carriers are provided with hooks, A A', having appendages,
_a a'_, which are fitted in the shuttle, O. The latter is of peculiar
construction. The upper ends of the hooks have fingers, _d d'_, which
holds the shuttle in position as long as the action of the springs, _e
e'_, continues. The distance that the shuttle has to travel includes the
breadth of the heddle, the length of the shuttle, and about four inches
in addition. The motion of the two carriers, which approach each other
and recede simultaneously, is effected by the levers, C, D, E, and C',
D', E'. The levers, E, E', are actuated by a piece, F, which receives
its motion from the main shaft, H, through the intervention of a
crank and a connecting rod, G, and makes a little more than a quarter
revolution. The levers, E, E', are articulated in such a way that
the motion transmitted by them is slackened toward the outer end and
quickened toward the middle of the loom. While the carriers, B B', are
receiving their alternate backward and forward motion, the shaft, I
(which revolves only half as fast as the main shaft), causes a lever, F
F', to swing, through the aid of a crank, J, and rod, K. Upon the two
carriers, B B', are firmly attached two hooks, M M', which move with
them. When the hook, M, approaches the extremity of the lever, F, the
latter raises it, pushes against the spring, E, and sets free the
shuttle, which, at the same moment, meets the opposite hook, _a'_, and,
being caught by it, is carried over to the other side. The same thing
happens when the carrier, B', is on its return travel, and the hook, M',
mounts the lever, F', which is then raised.
[Illustration: POWER LOOM FOR DELICATE FABRICS.]
As will be seen from this description, the woof does not undergo the
least strain, and may be drawn very gently from the shuttle. Neither
does this latter exert any friction on the chain, since it does not move
on it as in ordinary looms. In this apparatus, therefore, there may be
employed for the chain very delicate threads, which, in other looms,
would be injured by the shuttle passing over them. Looms constructed on
this plan have for some time been in very successful use in Switzerland.
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