Dotted or chenilled tulles are fabrics extensively used in the toilet
of ladies, and the ornamentation of which has hitherto been done by
the application to the tissue, by hand, either of chenille or of small
circles previously cut out of velvet. This work, which naturally takes
considerable time, greatly increases the cost price of the article.
A few trials at doing the work mechanically have been made, but without
any practical outcome. The workwomen who do the dotting are paid at
Lyons at the rate of 80 centimes per 100 dots; so that if we take
tulle with dots counter-simpled 0.04 of an inch, which is the smallest
quincunx used, and suppose that the tissue is 31 inches wide and that
the daily maximum production is one yard, we find that 400 dots at 80
centimes per 100 = 3 francs and 20 centimes (about 63 cents), the cost
of dotting per yard. It is true that the workwoman furnishes the velvet
herself.
Mr. C. Ricanet, of Lyons, has recently invented a machine with which he
effects mechanically the different operations of dotting, not only on
tulles but also upon gauzes or any other light tissues whatever, such
as those of cotton, silk, wool, etc. Aided by a talented mechanic, Mr.
Ricanet has succeeded in constructing one of those masterpieces of
wonderfully accurate mechanism of which the textile industry appears
to have the monopoly--at least it is permissible to judge so from the
remarkable inventions of Vaucanson, Jacquard, Philippe de Girard,
Heilmann, and others.
The object of this new machine, then, which has been doing its wonderful
work for a few days only, is to reproduce artificially chenille
embroidered on light tissues, by mechanically cutting out and gluing
small circles of velvet upon these fabrics.
For this purpose all kinds of velvet may be employed, and, in order to
facilitate the cutting, they are previously coated on the reverse side
with any glue or gum whatever, which gives the velvet a stiffness
favorable to the action of the punch. To effect the object desired the
apparatus has three successive operations to perform: first, cutting the
circles; second, moistening; and third, fastening down the dots upon the
tissue according to a definite order and spacing. The machine may be
constructed upon any scale whatever, although at present it is only made
for operating on pieces 31 inches wide, that being the normal width of
dotted tulles. The quincuncial arrangement of the dots is effected by
the punching, moistening, and fastening down of odd and even dots,
combined with the forward movement of the tissue to be chenilled.
The principal part of the machine is the cam-shaft, A (Figs. 1, 2, and
3), which revolves in the direction of the arrows and passes in the
center of 80 cam-wheels, 40 of which are odd and 40 even, alternately
opposed to each other. This shaft actuates, through its two extremities,
the different combined motions in view of the final object to be
attained, and also carries the motive pulleys, PP'. Figs. 1 and 2 show
the profile of two of these opposed cam-wheels--the arrangement by means
of which two rows of dots (odd and even) are laid down upon the tissue
during one revolution of the shaft or drum, A. Each of the wheels
carries three cams (Figs. 1 and 3), the first, (_a_), corresponding to
the punching; the second, (_a'_), to the moistening, and the third,
(_a''_), to the gluing down of the dots.
The annexed figure, one-quarter actual size, shows in section the
details of the cutting mechanism. To each cam-wheel there corresponds
one punch, and the eighty punches are arranged side by side and parallel
upon a shaft, B, a spring, _b_, holding them constantly against the
circumference of the cam-wheels. In Fig. 2 only one of these details is
shown. The punching arrangement consists of an ordinary punch, _c_, of
variable diameter, screwed to the extremity of a tube, _d_, which is
itself suspended from the end of the lever, _p_, but which can receive
from it at the desired moment the pressure necessary to effect the
cutting. The vertical position of these multiple tubes is insured by
a guide, _e_, which is thoroughly indispensable. Through each of the
tubes, _d_, there passes a plunger designed for expelling from the punch
the piece that has been cut out of the velvet, and for gluing it down to
the fabric. The two small springs, _b'_ and _b''_, tend continually to
lift the tubes as well as the plunger. The whole mechanism is affixed to
solid cast-iron frames, and the machine itself may be mounted on wooden
supports or a metal frame.
The punching is effected on a bronze straight-edge, C, which slides in a
cast-iron channel, D. This presents alternately, in its movement, entire
and punctured spaces, the former for receiving the blow of the punch and
the latter for allowing passage at the desired moment to the plunger
as it goes to fasten the dots upon the tulle which is passing along
underneath the channel, D. The punching is done primarily and
principally by pressure, but, in order to facilitate the complete
detachment of filaments which might retain the punched-out piece, the
punch is likewise given at the same time a slight rotary motion, thus
imitating mechanically what is performed by hand in the maneuver of all
punches. This rotary motion is communicated to the punches by means of
levers actuated by an eccentric, E, and which move the frame, _h_, whose
bars engage with the horizontal lever, _g_, soldered to the tube, _d_,
thus causing the latter at the very moment the punch descends to revolve
from right to left. The forty punches in operation cause the frame to
return to its initial position through the action of the springs, _b'_.
We say forty, since the inventor, in principle, has admitted 80 punches,
operating 40 as odd and 40 as even; obtaining in this way a dotting in
a regular quincunx of one yard, that is to say, 80 dots arranged in two
rows on a fabric 31 inches wide. But it is evident that a much larger
quincunx may be had by putting in play only a half, a third, or a
fourth of the punches, and causing the tulle and velvet to advance
proportionally. For this purpose it is only necessary to unscrew the
punches which are not to act, and to substitute for the ratchet wheel
which controls the unrolling of the I tulle, another having a number of
teeth proportioned to the desired spacing of the dots.
The punching having been executed, and the drum, A, continuing to
revolve, the punches rise a little owing to the conformation of the
cam-wheel, and through the action of the springs, _b_, and allow the
moistener to move forward to dampen the little circles which remain at
the orifice of the punches. The moistener or dampener is a sort of pad
equal in length to the field of action of the punches, and is affixed
to a cross-bar, F, which is connected at its two extremities with the
levers, G, that are actuated by the cam-wheels, H. These cam-wheels, or
eccentrics, H, which are mounted on the shaft of the drum, A, cause the
moistener to move forward as soon as the punches rise after operating,
and, when it arrives beneath the punches, the larger cams, _a_, of
the cam-wheels, A, press the latter upon the pad and thus effect the
dampening of the circles of velvet.
Immediately afterwards, the same eccentrics, H, acting on a lever, I,
uncover the holes in the straight-edge, C, and the channel, D. The
large cams, _a"_, of the wheel, A, then acting very powerfully upon the
respective punches, cause these latter to pass through the orifices so
that the extremity of each punch comes within about one twenty-fifth of
an inch of the fabric to be dotted. In this passage of the tube, _d_, a
small rod, _i_, connected by a lever with the plunger, _f_, is made to
abut against the guide, _e_, thus causing the descent of the plunger to
a sufficient degree to push the velvet "dot" out of the tube and to glue
it upon the fabric. The manner in which these operations are performed
being now well enough understood, let us for a moment examine the
motions of the fabrics to be cut and dotted--the first being velvet or
any other material, even metal (goldleaf, for example), and the second,
the tulle.
The latter has but one motion, and that is in the direction of its
length, while the velvet has, in addition to this same motion, another
slight one from right to left in the direction of its width in order to
diminish waste as much as possible.
The tulle to be dotted is first wound around a roller, R, from whence it
passes over the glass guide-roller, R', and between the channel, D, and
the table, T, to the roller, R", which is heated by steam.
The hot air which is radiated dries the dots, and from thence the fabric
is taken up by other rollers or by any other method. The steam roller,
R", carries at one of its extremities a ratchet wheel whose teeth vary
in number according to the greater or less rapidity with which the tulle
is unrolled. It is actuated by a lever which receives its motion from
the eccentric, K.
[Illustration: IMPROVED MACHINE FOR DOTTING TULLAND OTHER LIGHT
FABRICS.]
In the table, T, there is a rectangular receptacle, _t_, containing
rasped or powdered velvet for the purpose of forming a reverse of the
dot. This powder attaches itself to the gum and imitates on the wrong
side of the fabric a dot similar to that on the upper or right side. The
velvet is wound upon the roller, _r_, and from thence passes under the
guiding roller, _r'_, the punches, and the second roller, _r"_. These
two latter rollers are solidly connected by a straight-edge fixed at the
extremity of the lever, L, whose other end is in continuous correlation
with the eccentric, M, which controls the lateral displacements;
while the eccentric, O, actuates, by means of the screw, Q, and the
ratchet-wheel, S, the longitudinal advance of the velvet. The eccentric,
M, is fixed upon an axle, A', which carries a wheel, U, having teeth
inclined with respect to its axis, and which derives its motion from the
Archimedean screw, N, fixed at one of the extremities of the cam-shaft,
A.
We have stated above that the maximum daily hand production of tulle
dotted in quincunxes of 0.04 of an inch is about one yard. At the rate
of 30 revolutions per minute, and for the same article as that just
mentioned, this dotting machine is capable of producing, theoretically,
360 yards per 10 hours; but practically this production is reduced to
about 250 yards, which, however, is sufficiently satisfactory.
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