carriage is at its outermost point, and the winding faller is locked,
the wire is, as previously mentioned, a little below the nose of the
cop. As the inward run proceeds, the bowl first runs up the loose
incline, thus raising the locking lever and depressing the winding
faller wire. The distance, from the extreme outward point reached by
the bowl =L^{1}= and that where the loose rail =Q= is hinged and the
downward inclination of the copping rail begins, is so short that
the initial depression of the winding faller is very rapid. This
produces the coarsely pitched coils referred to in paragraph 317, and
illustrated in Fig. 164. By the time the bowl =L^{1}= is at its highest
point the winding faller wire is opposite the base of the upper cone.
The subsequent downward inclination of the copping rail is much less
acute, and the consequent descent of the faller locking lever less
rapid. As a result the upward traverse of the winding faller wire
is made more slowly, and the yarn is wound in more finely pitched
spirals. It only remains to be said, in connection with this part
of the subject, that owing to the shape of the copping plates their
inward movement is accompanied by a gradual fall of the copping rail,
and, consequently, the locking point of the faller lever is relatively
elevated. In other words, the traverse of the locking lever prior to
locking is gradually lessened as the trail lever slide =L= is lowered,
and this is equivalent to an elevation of the winding faller lever and
its locking point or shoulder =K=. This causes the depression of the
winding faller wire prior to locking to be gradually diminished, so
that there is an elevation of its initial point.
(323) The method of obtaining the traverse of the winding faller having
been described, the equally important points relating to the mode of
rotating the spindle during winding require to be dealt with. A little
thought will show that so long as the surface upon which the yarn is
wound remains small the spindles must revolve at a more rapid rate
than when the surface is enlarged. As the extreme diameter of the cop
bottom is enlarged the conditions of successful winding are continually
changing. At the commencement of the cop the yarn is wound upon what
is practically a parallel surface with a diameter of 5/16 inch and a
circumference of ·98 inch. This implies that to wind the 63 inches
of yarn 64·3 revolutions are required, these being made during the
run up of the carriage. But as the diameter of the cop is enlarged
the circumference of the conical surface becomes a variable one, and
owing to its enlargement the number of revolutions required to wind
the same length of yarn is fewer. This is quite clear and needs no
demonstration. Thus when the cop bottom is formed the extreme range
of variation is reached, and it follows that in the interval between
the commencement of winding and the formation of the cop bottom each
stretch must be accompanied by a diminution of the velocity of the
spindle proportionate to the increase of diameter. In addition to this
it is necessary to take into consideration the varying diameter of the
conical surface on which winding takes place, which necessitates a
greater terminal than initial velocity of the spindle.
[Illustration: FIGS. 163 AND 164. J.N.]
(324) A further point requires elucidation. If the spindle blade were
parallel, the number of revolutions necessary to wind the 63 inches of
yarn properly, when the cop bottom is formed, being fixed, no further
alteration would be necessary. But these conditions do not exist, and
the nose of the cop is wound upon a continually diminishing diameter.
It is of the utmost importance that the yarn is wound tightly at the
nose during the whole of the building of the cop. The rate of the
vertical traverse being practically uniform, unless an acceleration of
the spindle velocity occurred, there would be slack winding during the
latter part of the building of the cop. This would produce a sponginess
of the nose, which, when the yarn was drawn off in the subsequent
process of winding, as shown by the arrow in Fig. 164, would result in
several rings or coils being pulled out in an entangled condition, thus
producing waste. Technically the cop would be said to be “halched.”
Illustrating this part of the subject by figures, if the diameter of
the spindle at the point =B=, Fig. 163, be assumed to be 1/4 inch, its
circumference would be ·7854 inch; while if the diameter at =H= be
assumed to be 1/8 inch, the circumference would be only ·3927 inch. To
wind, say, 10 inches of yarn in each case, would require about 12 and
25 revolutions of the spindle respectively. It is therefore clear that,
if the same length is to be wound with equal tension upon the nose of
the cop throughout the whole process of building, there must be a
gradual acceleration of the terminal velocity of the spindle. Although
this is only slight at first it is required at an earlier point as the
cop is formed, and becomes of increasing importance.
[Illustration: FIG. 166. J.N.]
(325) It will be shown, a little later, that the rotation of the
spindles during winding is obtained by the pull of the carriage on a
chain, which has its other end attached to an oscillating arm, being
fastened to a drum on the carriage. To get a clear idea of the action
of this part of the mechanism the two diagrams shown in Figs. 166 and
167 are given, a study of which will be profitable. In Fig. 166 the
circles =B C D= represent three positions of the barrel or drum after
it has moved in a horizontal plane in the direction of the arrow. To
the drum a chain is supposed to be attached, which is held at the point
=A=. It is, of course, understood that the barrel is mounted upon a
shaft or axis so that it can freely revolve. If it be now assumed that
the barrel is in the left hand of the three positions =B=, the chain
will be wrapped completely round it. As it is moved horizontally in
the direction of the arrow it is revolved, as indicated by the curved
arrows, and, by the time it has reached its middle position =C=, has
been rotated sufficiently to unwind about half a turn of the chain. A
further horizontal motion to the right hand position =D= will complete
the unwinding, and, by this time, the drum will have made one complete
revolution. It will be at once seen that the rate at which the drum
will be revolved will depend upon two factors—its diameter, and the
speed of its horizontal traverse. If the point =A= at which the chain
is held is stationary, and the horizontal movement uniform, then the
rotation of the barrel will be constant. But if the barrel be traversed
at a variable rate then its rotation will also be variable. In actual
practice this uniformity does not exist, for, as was shown in paragraph
315, the taking-in scrolls vary considerably in diameter. Assuming this
variation to be 1:3:1, it would follow that the rotation of the barrel
would increase and diminish in the same ratio. In practice this is
what happens, and the speed of the revolution of the barrel is quicker
about the middle of the taking-in than at any other time.
(326) The assumption that the point =A= is stationary was only made to
illustrate the point at issue, and is not founded upon the actual facts
of the case. If now it be assumed that not only the barrel but the
point at which the chain is held makes a forward movement, a new set
of conditions arises. In this case the unwinding of the chain during a
given time will be diminished by the amount of the advance of the point
=A= in the same period. Assuming the latter to be made at a regular
rate it would be easy to calculate the extent of the unwinding. If the
effect of the horizontal movement of the barrel from =B= to =C= be to
unwind half of one coil of chain—say a length of 7 inches—and that in
the same space of time the point =A= moved 3 inches, the amount unwound
would be reduced to 4 inches. But this is not the actual condition of
things in practice. The point moves at a variable velocity, its forward
motion gradually diminishing, so that the acceleration of the rotary
velocity of the barrel is greater at the end of its horizontal traverse
than at the beginning. In other words, its terminal velocity is highest.
(327) The point of the attachment of the chain at =A= is made in an
oscillating arm which, during the inward run of the carriage, receives
a forward movement at a speed which is controlled by the velocity of
the back shaft. As the latter is, in turn, commanded by the scroll
shaft during this period—see paragraph 315—it follows that the
variation in the forward movement of the arm is coincident with that
of the carriage. Thus the advance of the point =A= will always be in
strict correspondence with the velocity of the carriage traverse.
(328) Referring now to Fig. 167, and, assuming =A B= to be the arm to
which the chain is fastened, and =O J= and =H C= to represent the arcs
through which the point of attachment of the chain travels at different
times, it will be seen that the periods of movement are well marked.
In each case the arcs are of the same number of degrees, although the
chord of one is shorter than that of the other. Dealing first with the
inner arc, which represents the position of the point of attachment
when nearer the centre, the whole period of movement is divided into
equal parts. These are represented by the letters =J K L M N O=. Now,
if vertical lines are drawn from these, until they terminate in a
straight line drawn parallel to a horizontal line through the point
=B=, a clear idea can be formed of the effect of the oscillation of the
vertical arm =A B=. The lines terminate at =J^{1} K^{1} L^{1} M^{1}
N^{1} O^{1}=. It can be easily seen that the horizontal movement of
the point of attachment of the chain gradually becomes less as the
arm is oscillated from its most backward position =B C= to its most
forward one =B H=, this diminution occurring most after the point
=L= is reached. In the movement from =J= to =K= and =K= to =L= the
horizontal traverse is about equal. It shows a decrease from =L= to
=M=, a greater one from =M= to =N=, and a still greater one from =N= to
=O=. The same thing happens if the chain be supposed to be attached at
the point =D=. In this case also the decrease in the horizontal forward
traverse is variable, but occurs in the same way. The periods here are
marked by the letters =C= to =H=, and the extent of the forward motion
by those =C^{1}= to =H^{1}=. It will be noticed that the amount of the
traverse is greater than that previously noted, the total space covered
being respectively =J^{1}= to =O^{1}= and =C^{1}= to =H^{1}=. That
is to say, the point at which the chain is fastened moves forward in
the same direction as the barrel, but at a different speed. In other
words, when the chain is held at =K=, the total forward movement is
comparatively small, and if it were held at a point shown by the small
inner circle, it would be still less. On the other hand, its attachment
at =B= implies a greater total forward movement. It therefore happens
that the retardation of the chain by the arm is less in the early part
of the oscillation of =A B=—or, to put it differently, the delivery of
the winding chain by the arm is greater when it is fixed at =D= than
when it is fixed at =K=. Therefore the barrel is more slowly rotated
during the same period in the former than in the latter case, but
as it completes its lateral movement it is rapidly and considerably
accelerated.
(329) The application of this principle is as follows, and it can now
be stated that the end of the chain is attached to a nut which slides
along the arm, being actuated by the rotation of a screw upon which
it fits. Remembering that an acceleration of the terminal velocity
and a regulation of the revolution of the spindle is required, the
demonstration just given shows that these are obtained by the removal
of the nut further from the centre of oscillation. The influence of
the pull of the chain upon the barrel when the nut is in the position
=K= is much slighter, and shows less variation than when it is at =D=.
Every inch which the nut travels outwards has an influence upon this
factor, and the conditions of winding are thus accurately regulated.
When the winding of the cop begins, the nut is in its lowest position,
and the rotation of the barrel is then practically equal. As the nut
moves away from the centre the barrel gradually rotates more slowly
at the beginning of its inward movement. By the time the most outward
position is reached—which, in practice, coincides with the formation of
the cop bottom—the variation in the velocity has reached its greatest
amount. This, it can be easily seen, is what is wanted. Referring again
to Fig. 163, one revolution of the spindle when the yarn is being wound
on =A D= would practically take up the same length as would be taken
up at the top of the paper tube. But when the faller is guiding the
yarn on the conical surface from =E= to =B=, one revolution of the
spindle would wind on a greater length at =E= than it would at =B=.
Therefore, the initial velocity requires to be less than the terminal.
But when the point =E= has become the initial position, the conditions
of winding remain thereafter constant, except in so far as is affected
by the taper of the blade, and there is no further need for an outward
movement of the nut.
(330) The theory underlying the method of winding having thus been
dealt with, the mechanism employed can be described. This is shown in
Fig. 168, which is a diagram of the whole of the apparatus, and in
Fig. 169, which is an enlarged view of a portion of it. The winding
arm =M= is centered at its lower end, and has formed on it a toothed
quadrant =M^{1}=. The “quadrant” =M= oscillates on a short shaft,
securely carried by the headstock framing, and receives its forward
movement by means of a pinion =Z=, which engages with its teeth. The
extent of the quadrant movement is about a quarter circle. The pinion
=Z= is mounted on the same centre as a grooved pulley, over which a
cord from the back shaft =H= is passed. Thus the rotation of =H= in
either direction produces a similar movement in the pinion =Z=; and the
effect is, that, while the back shaft is drawing the carriage out, the
pinion is revolving so as to raise the arm =M= or cause it to make a
backward oscillation. When the back shaft acts as a taking-in shaft, as
described in paragraph 315, the pinion =Z= is revolved so as to move
the arm =M= forward. The velocity at which the forward stroke is made
is by this arrangement a variable one, and completely corresponds to
that of the carriage traverse. Inside the winding arm a long slot is
formed in which a screw =P= is placed, this being free to revolve. It
may be made with a thread of equal pitch throughout, but, as shown, is
provided with a thread of varying pitch, which gradually becomes finer
towards the outward end of the arm. The reason of this is obvious. The
effect of each layer of yarn upon the problem of winding is greater
at the beginning of the formation of the cop bottom than when it is
more nearly finished. That is, the enlargement of its diameter is
relatively greater at the first stage than at any other. For instance,
if the diameter is 3/8 inch and it be increased 1/16 inch, the ratio is
1/6th; while if the diameter is 3/4 inch, and the same increase takes
place, the ratio is 1/12th only. The variation required in the speed of
winding as each layer is wrapped is therefore less in the latter than
in the former case. This is the purpose of the helical screw, which
gives a quicker advance to the nut in the earlier stages of winding
than when the cop bottom is nearly formed.
[Illustration: FIG. 167. J.N.]
[Illustration: FIG. 168. J.N.]
(331) The screw has fixed upon it, at its lower extremity, a small
bevel pinion, gearing with a similar one placed loosely on the short
shaft forming the centre for the arm. During the oscillation of the
arm the pinion moves with it, and it is clear that if both remained in
this position only this alternate action would occur, and no rotation
of the screw would be made. If, however, the pinion on the short shaft
be rotated it communicates its motion to the screw =P=, and thus
traverses the nut. This is what takes place, and the precise method of
effecting it will be described in detail at a little later period. The
nut engages with the screw and originally had an eye or hook formed in
it, to which the end of the winding chain or band =C= was fastened. The
attachment is now made in a different manner, a frame =A= being fixed
to the nut along with which it can slide. At the upper end of the frame
a small drum is carried, round which the winding chain is wrapped,
passing over a small bowl =D= at the lower end of the frame. The
other end of the chain or band =C= is fastened to the drum or scroll
=X^{1}= which is mounted on a shaft =X= carried in suitable bearings
in the square. On the same shaft a spur wheel is geared which engages
with a pinion loose upon the tin roller shaft, which it revolves by
special mechanism afterwards described in detail. The use of a scroll
is intended to accelerate the revolutions of the spindles during the
latter part of the fallen traverse. This, like the winding arm, is a
modified application of the fusee, and it will be easily understood
that when the chain is being unwound from the larger diameter of the
scroll, the number of revolutions given to the scroll will be less than
when it is being taken off the smaller diameter.
(332) It has been previously shown that the diminishing diameter of
the spindle causes it to be necessary that, as the cop is built higher
upon it, a correspondingly higher rotary velocity shall be given to it,
in addition to the increased terminal velocity produced in the manner
described. The most usual method of doing this has been to provide
at the end of the quadrant arm a bracket carrying a pin known as the
“nosing peg.” The object of this device is to shorten the chain by
deflecting it from a straight line about the time when the carriage
nears the end of its inward run. This is equivalent to a sudden
shortening of the chain, and gives a sudden acceleration to the winding
drum. In some cases an automatic arrangement is fitted by which the
peg is brought into contact with the chain at an earlier point every
stretch, so that the acceleration of the spindle takes place sooner,
as the nose of the cop is formed higher up the spindle. It is not
difficult to obtain a clear notion of the action of the nose peg if a
short length of string be held at one end and attached to a sliding
piece at the other. If then the string be pressed down by a rod at the
same point, but a little further every time, it will be seen that the
sliding piece is moved to a greater extent with each depression.
(333) The arrangement used in the Platt mule is shown in detail in Fig.
169. It consists of the sliding bracket A, carrying, as described,
at its upper part, a small drum on which the winding chain =C= is
fastened. On the spindle of the winding drum a ratchet wheel =E= is
fixed, with which the detent pawls =E^{1}= engage, thus ensuring that
=E= is held in any position assumed by it. Also fastened on the spindle
of the drum is the curved sector arm =F=, to which a chain =G= is
secured. By means of the guide pulleys shown the chain =G= is conducted
over the arm or lever =K=, and is attached to the bracket =I=. The
lever =K= is hung from its upper end, and has a projecting short arm
=K^{1}= attached to it, which can move upwards in the direction of
the arrow. The outer end of =K^{1}= presses against a bracket =K^{2}=
attached to the quadrant, so shaped that the backward movement of the
quadrant pushes the lever =K= back at its lower end. In the bracket
=I= a finger =I^{1}= engaging with the copping nut is fixed. The parts
having been adjusted to their proper position the slide =A= is at the
bottom end of the quadrant =M=, as shown, and the curved arm =F= is
in such a position that it has wound upon it a certain length of the
chain =G=. The latter is a little slack at first, but as the nut moves
out this is rapidly taken up until the chain =G= is in tension. As
soon as this happens, each of the forward oscillations of the arm =M=
leads to the chain being drawn, and causes the lower end of the lever
=K= to be swung forward. The return movement of the quadrant leads
to the bracket =K^{2}= pressing upon the arm =K^{1}=, so as to push
back the end of the arm or lever =K=. In this way the chain =G= is
pulled and the curved arm =F= is drawn a little forward, thus causing
the drum and ratchet wheel =E= to revolve. As the winding chain is
wound on the barrel, every rotary movement of the latter in a forward
direction takes up a little more chain and shortens its length. The
amount of this shortening is not great up to the time of the completion
of the cop bottom and the arrival of the slide =A= at the end of its
traverse along the arm. The position of the parts at this period is
shown in the detached view at the right hand top corner of Fig. 169. Up
to this time only about the same length of chain is taken up which is
needed by the increased distance of the slide =A= from the centre, and
the greater forward traverse of the quadrant arm, which, in a sense,
releases a certain length of winding chain. When this point is reached
the finger =I^{1}= begins to be pressed against by the nut =S^{1}= of
the shaper screw, and the bracket =I= commences to be drawn inward. To
facilitate the correct action of this mechanism the finger =I^{1}= is
adjustable, and the exact moment of its contact with the nut =S^{1}= is
thus regulated. The forward movement of the shaper nut which follows
gives a similar motion to the bracket =I=, and the chain =G= is thus
drawn forward. In this way the drum and ratchet wheel =E= are rotated,
and the winding chain gradually shortened. Thus more of it is unwound
from the scrolls at each traverse of the carriage, and as it is drawn
from the smaller diameter of the scroll towards the end of the run in,
the velocity of the spindles is considerably accelerated. The position
of the various parts when the carriage is at the back stops is shown in
Figs. 170 and 171.
(334) These represent respectively the places occupied by the different
portions of the mechanism immediately at the completion of the cop
bottom, and at the finish of building a set of cops. The positions of
the various parts connected with the slide =A= when winding is complete
are shown also in Fig. 169, at the top end of the quadrant arm.
Referring to Fig. 170, it will be noticed that the winding chain =C= is
unwound from the large part of the scroll only, while Fig. 171 shows it
almost entirely unwound from the smaller portion. As was shown, this
implies a high terminal velocity of the winding scroll and spindles.
(335) It has been previously mentioned that the rotation of the
quadrant screw is obtained by means of the engagement of two bevel
wheels, one on the foot of the screw and the other upon the spindle,
forming the centre of the quadrant. It was also stated that the
last-named wheel was held so as to move round the centre with the
quadrant. This is effected by means of a brake spring =P^{2}= which
clips the boss of the wheel and holds it. The resistance thus created
causes the bevel wheel to move with the quadrant, and prevents it from
rotating on its axis. The wheel is compounded with a grooved cord
pulley =P^{1}=, over which an endless band =Q= passes. The band =Q=
fits the groove in the pulley, and is afterwards guided by the various
carrier pulleys shown. Two of these, =S S^{1}=, are borne by brackets
fixed to the carriage, and =S= is formed with teeth so as to allow
of the engagement of the vertical detent catch on the lever =Y=. If
the whole of the pulleys over which the band =Q= passes are free to
revolve, except that on the quadrant centre, the inward run of the
carriage gives no motion to the cord or band. No effect is produced
beyond the rotation of the carrier pulleys, and the forward stroke
of the quadrant is made without any effect being produced upon the
position of the nut.
(336) It was shown that the gradual accretion of yarn by the cop
results in the necessity for a graduation of the velocity of the
spindle in winding. This takes place during the whole period of
building, and it follows that the traverse of the nut must be governed
during the whole period. After a layer of yarn has been wound the nut
remains in the position occupied by it during the preceding inward
run, until the carriage has made another outward run, and is again
commencing to run in. At the commencement of the run in of the
carriage the spindles revolve at the same speed as that at which they
rotated in the preceding period of winding. If the yarn is a coarse one
this is sure to be too fast, because of the increase in the diameter
of the cop, owing to the yarn wound during the last inward run. The
initial velocity of the spindles is, therefore, such that they take up
the yarn too rapidly, and put an extra amount of tension upon it. As
was shown in paragraph 303, this causes a depression of the counter
faller wire. This is utilised to revolve the quadrant screw and
traverse the nut and slide. In other words, the winding is said to be
“governed,” and the motion is known as the “governing” or “strapping”
motion.
[Illustration: FIG. 169. J.N.]
(337) Fixed on the winding faller and counter faller shafts =B B^{1}=
(Fig. 168) are two arms =U U^{1}=, to which the ends of a light chain
=Y^{1}= are attached. The chain passes round a runner, or pulley,
placed in the outer end of the hinged lever =Y=, which is in this way
sustained. It is obvious that the vertical position of the lever will
be strictly regulated by the position of the two arms =U U^{1}=. As
they follow the oscillations of the winding and counter faller shafts,
the elevated position of these during spinning ensures the lever =Y=
being raised at its free end. This results in the tooth, or detent,
being taken out of contact with the teeth on the pulley =S=. When the
counter faller is depressed by reason of the tension of the yarn upon
it a similar movement occurs in the lever =Y=.
(338) In the early stages of winding, when the winding faller is
depressed to a comparatively large extent prior to being locked, the
vertical position of the lever =Y= is naturally lower than when the
winding faller is not pushed down so far. It thus occurs that, when
the cop bottom is being formed, which is the stage during which the
traverse of the nut is required, and the winding faller is locked at
its lowest point, the clearance of the detent catch on =Y= and the
teeth on the pulley =S= is least. At this period, therefore, they are
most easily engaged by any depression of the counter faller. When
the higher initial velocity of the spindle, produced as described in
paragraph 336, causes the yarn to be put into tension and the counter
faller wire depressed, an engagement of the catch and pulley teeth
occurs.
[Illustration: FIGS. 170 AND 171. J.N.]
(339) The effect is that the rotation of the toothed pulley is stopped,
and the band =Q= is practically gripped by =S= and its fellow pulley
=S^{1}=, which are borne by the carriage. Instead, therefore, of
slipping over the pulleys as before, the band is drawn along with the
carriage and the remaining pulleys are caused to revolve. The force
so applied is sufficient to rotate the grooved pulley =P^{1}= by
overcoming the resistance of the spring clip, and the bevel wheels and
quadrant screw are rotated. The nut is thus moved outwards, and the
winding chain relieved as previously described. This causes a slight
diminution in the speed of winding, sufficient to relieve the pressure
of the threads on the counter faller wire, which rises and breaks the
contact of the detent and the toothed pulley. The further movement of
the nut is thus arrested.
(340) The necessity for a diminution of the initial velocity of the
spindle is strictly relative to the counts of yarn being spun. Some of
the finer counts require a very slow traverse of the nut, and there may
be practically none during several draws of the carriage. As the nut
slowly rises and the locking point of the winding faller is elevated,
the period of the engagement of the detent catch and the wheel =S=
becomes shorter, and the rotation of the screw is not so prolonged.
When the cop bottom is fully formed, the nut is at its most outward
point, and the “governing” motion is not therefore required. At this
point, the relative positions of the arms =U U^{1}= are such, that the
chain =Y^{1}= will not permit the lever =Y= to fall sufficiently to
allow its tooth to engage with the wheel. The motion, therefore, falls
out of use until the commencement of another set of cops.
(341) The motion of the winding scroll is communicated to the tin
roller by means of a catch or “click” plate shown in detail in
Fig. 168. On the spindle of the winding scroll =X^{1}= is a spur
wheel—indicated by dotted lines—which engages with a small pinion on
the tin roller shaft =T=. The whole of this special mechanism is shown
in longitudinal section in the right hand top corner of Fig. 168. The
pinion is cast in one piece with the disc =V= which is loose upon the
shaft =T=. The latter has a pin fixed in it, on which the small catch
or “click” =V^{1}= is hinged. The click catch is ordinarily held out
of position by the bent spring =W^{1}=, which surrounds the boss of a
ratchet wheel =T^{1}=—to which the name of the “click wheel” is given.
When the “click spring” =W^{1}= is slightly oscillated in the same
direction as the rotation of the ratchet wheel, it allows the click
catch to fall into gear with the click wheel. As the latter is keyed
upon the tin roller shaft =T=, the engagement with it of the catch
causes the tin roller to be revolved, and thus rotates the spindles.
(342) It was formerly the practice to allow the click catch to fall
into gear when the disc =V= began to rotate upon the commencement of
the inward run of the carriage. It was, however, found that the click
catch engaged with the wheel earlier at one stretch than at another,
and that, consequently, winding began a little more slowly than it
should. The effect of such an occurrence is that a little slack yarn
was produced as the carriage was running in, although winding was
not taking place. Under these conditions tight winding at the nose
throughout was practically impossible. It will be easily understood
that, when the click catch is released, it may very readily be left
either close to the tooth with which it has to engage or only just over
the point of the preceding tooth. In the first case the engagement
would take place at once, while in the second instance almost the
distance of a tooth would have to be travelled by the click catch
before engagement occurred. In hard twisted yarns this is especially
objectionable, and its prevention is of importance.
(343) To overcome the defect thus explained a hanging lever =W= is
fitted on the tin roller shaft, and the click spring =W^{1}=, instead
of fitting on the boss of the disc =V=, fits on the inner boss of
the lever =W=, which it clips. A slight oscillation of the lever is,
therefore, at once followed by the movement of the spring, and the
click catch is engaged. The tail end of the lever =W= comes in contact
with a stop =R^{1}= on the holding-out catch rod =R=. When =R= is moved
in order to release the catch it causes the lever =W= to move into
the position shown by the dotted lines, and so oscillate the spring
=W^{1}=. The tail of the click spring passes between a fork formed
in the click catch, and thus presses the catch in either direction,
according to which side of the fork it gears with. When, therefore, the
click spring is oscillated by the releasing movement of the holding-out
rod acting upon the lever =W=, the click catch is forced hard up to the
tooth with which it is engaging. The continued movement of the rod, if
made, has, of course, no further effect upon the click catch, but the
parts are quite ready for winding with the click in gear. Immediately
the carriage begins its inward run winding commences. Thus, whatever
may be the position of the click catch at the end of an outward run,
it is always ready for its work before the inward run commences. The
weight of the rod =W= is sufficient to keep the click catch disengaged
during the whole period of spinning and backing-off.
(344) The whole of the points relating to winding having been
considered, the motions used in the fifth and last period require
describing. When the carriage is near the completion of its inward run,
the various parts are in the following position: The strap is on the
loose pulley and the backing-off side shaft is being revolved either by
the gearing named, or by its independent band; the back shaft clutch is
disengaged and the back shaft is revolving so as to aid in drawing up
the carriage; the rollers are disengaged and are not delivering roving;
the taking-in friction is engaged, and the scroll bands are drawing
in the carriage; the quadrant arm is completing its forward movement,
and the spindles are revolving in their normal direction; the winding
faller is locked and the wire is approaching the nose of the cop; and
the counter faller is in contact with and sustaining the threads. As
soon as the carriage arrives at the roller beam, the whole of these
motions require changing, so that the different parts shall occupy the
positions indicated in paragraph 286.
(345) This operation is mainly the work of the cam shaft, but in part
is performed by other mechanism. As soon as the carriage arrives at,
or near, the end of its outward run, the horn =S^{1}= on the carriage
comes in contact with the anti-friction bowl =R^{1}= in the long lever
=T= and depresses it (see Fig. 156). This removes the nose of the
releasing lever from the raised surface on =V= and allows the friction
clutch =W X= to come into gear. The cam shaft immediately begins to
rotate, and the three cams to act upon the various parts in the reverse
way to that previously described. The rotation of the cam =Z= (Fig.
156) performs the two functions of disengaging the taking-in friction
clutch and engaging the back shaft clutch, the motions of these always
being closely related. The cam =W= during the same period allows the
roller clutch to go into gear, and the delivery of roving again begins.
The rotation of the cam =Y= causes it to exercise a thrust on the pin
fixed in =G= (Fig. 158), so forcing the driving strap over on to the
fast pulley, this giving renewed motion to the spindles. The same
movement causes the lever =H= to be pushed forward until the shoulder
formed in it can again engage with the fixed catch =L=, the spring
=P= pulling the end of =H= upwards as soon as it is sufficiently far
forward. The strap guider is thus again locked when the strap is on the
fast pulley. By the time these engagements and disengagements have been
made, the cam shaft =M= has made its second half revolution, and the
end of the release lever again presses upon the raised surface on the
cam =V= and detaches the friction cone =W= from =X=. The cam shaft is
thus stopped and remains stationary until the end of the outward run as
described in paragraph 291.
(346) The whole of the parts governed by the cam shaft having thus
resumed their original position, it remains to be shown how the winding
and counter fallers are released, so as to be able to assume their
relative positions out of contact with the yarn. The unlocking of the
winding faller must be made as late as possible in the inward run, but
the exact period at which it is made is affected by the height of the
cop nose on the spindle. The termination of winding requires to be
made throughout the whole period of building a set of cops, at such a
point as to leave sufficient yarn to coil on the spindles between their
points and the cop nose. It will be easily seen that this quantity is
varying throughout the whole of the formation of the cop, and that
the length to be wound on is greatest at the commencement of the cop.
This implies the unlocking of the winding faller at a point which is
made gradually later, and this is well carried out in the Platt mule.
At the lower end of the locking lever is a curved arm or “boot leg,”
which, at the termination of the inward run, comes in contact with
the fixed stop bracket =G= (Fig. 161). The face of this is so shaped
that the moment of unlocking is regulated in accordance with the
requirements of the case throughout the whole of the formation of the
cop. This is an important point, and requires careful attention. In
a special form of mule, made by Messrs. Platt Brothers and Co., for
finer counts, the stop bracket is a movable one, and is released by the
run of the carriage, so as to slide forward and unlock at the exact
moment required. The finer the yarns the more care is required in this
respect, owing to their greater liability to breakage.
(347) Referring now to the release of the winding and counter fallers,
it is essential that they should leave the yarn free as soon as
spinning begins. For this purpose the lever =J= is raised by contact
with the small roller =W= (Fig. 159), and its weight is removed from
the counter faller shaft, and also from the winding faller. Still
further to facilitate the descent of the counter faller, which is
sometimes a little sluggish, a stop is placed in the headstock, which
engages with a tail piece on the counter faller shaft when the carriage
has run in. This arrangement is shown in the dotted lines at the
right hand top corner of Fig. 161. The weight of the winding faller
connections is, of course, sufficient to lift it quickly out of contact
with the yarn.
(348) The operations thus described constitute the fifth period, and at
its termination the mechanism is again engaged in the work of spinning
or twisting, being at the commencement of another cycle of movements.
There is, however, one more piece of mechanism to refer to before the
description of this machine can be brought to a close. It was seen
that during the period of winding the chain was drawn off the winding
scroll during the forward stroke of the quadrant arm. Referring to
Fig. 172, which represents a portion of the mechanism relating to the
quadrant, it will be seen by the arrows that during the outward run of
the carriage, the quadrant =M= also makes its backward stroke. During
the same period it is necessary to rewind on the winding scroll the
chain =C= which was previously unwound, and this is effected by the
cord =S=. =S= is attached at one end to a hook or staple =T=, fixed
to the framing, and at its other end to a weighted lever =U=, pivoted
on a bracket fixed to the floor. The cord =S=, in its course, passes
over the two pulleys shown fixed to the carriage, and its tension
is sufficient to cause the pulley on the shaft =X= to be rotated by
the inward run of the carriage, thus winding the chain =C= on to
the scroll. By the termination of the outward run this operation is
concluded, and the chain is ready to act again efficiently as soon as
winding recommences. When a “set” of cops—that is, the whole number
spun on a mule—is finished, it is “doffed” or stripped from the
spindles. As soon as this is completed the winding nut is wound back
by hand to the bottom of the quadrant, and the copping plates are also
restored manually to their original position.
(349) The description thus given of the machine as made by Messrs.
Platt will enable an accurate idea to be obtained of the mechanical
movements which are found in the work of a mule. It is true that this
special machine differs in some of its details from many of other
makers, and that there are motions fitted to it which are not found
in other machines. When the latter are used, however, they tend to
increase the automaticity of the machine. The winding chain shortening,
or, as it is more correctly called, the nosing motion, and the
backing-off chain tightening motion, are of this class, both tending to
an increased efficiency. The main principles in a machine of this class
are embodied in the mule described, and the general explanations given
will prove serviceable, whatever may be the make of mule studied.
[Illustration: FIG. 173. J.N.]
(350) One of the important points of difference between this and mules
of other makes is found in the position of the cam shaft. This, it was
seen, is in the Platt machine placed above the axis of the rim shaft.
In other cases it is placed, as shown diagramatically in Fig. 173,
along the headstock of the mule, and below the centre of the long or
“balanced” lever =T=. In this case the cam shaft =K= is a tubular one,
and has passed through its centre the shaft =M=, which is suitably
driven from one end. The cam shaft is fitted with a friction clutch at
=P=, the fixed half being on the tubular shaft. The other half slides
on the shaft =M=, being pressed up to the fixed half by the spiral
spring shown. On the long lever =T= at the point =L= a pendant cam
plate is hung, which surrounds the cam shaft as shown in a detached
front view and section in Figs. 174 and 175, and is formed with a
slot so as to permit it to rise and fall freely. The cam plate has
two raised cam surfaces or courses, against which the end of a pin is
pressed by the action of the spiral spring. The pin passes through the
half clutch fixed on the cam shaft, and presses against the sliding
half on the shaft =M=. Thus when the pin is on the raised part of the
cam plate the clutch is detached, while if it is on the lower part the
clutch is in gear. When, therefore, the inner end of the balanced lever
=T= is depressed, the fall of the pendant plate causes the pin to come
upon the lower part of the cam course, and permits the engagement of
the clutch. The cam shaft thus makes a half circle turn, and effects
the necessary changes for beginning spinning. This causes the end of
the pin to run on to the second cam course, and by the time the half
revolution is made, it comes on the raised surface and disengages the
cam. In this position it rests until the outer end of the long lever is
depressed, when a similar action occurs, terminating in a similar way.
[Illustration: FIG. 172. J.N.]
(351) The back shaft is also engaged and detached in a different
manner. It is driven from the roller shaft by a train of wheels, but
the last of the train is a compound one, consisting of a large wheel
with a smaller pinion. The latter gears with the back shaft wheel, and
is put into or out of gear accordingly, as it is desired to revolve
or stop the rotation of the back shaft. For this purpose the compound
wheel is borne on a hinged lever, called commonly the Mendoza lever,
which is weighted in a suitable manner. The exact origin of the word
Mendoza, as applied to this lever, is difficult to define, but it
probably arises from the French phrase, _main douce_—Anglicè, the soft
hand. However this may be, the function of the lever is to put the
pinion into and out of gear with the backing-off wheel, and to effect
this, its motion is controlled by a cam or eccentric on the cam shaft.
This cam works in a fork in a lever, and the rotation of the cam shaft
raises or lowers the Mendoza. The object of the weight is to ensure the
full engagement of the pinion and back shaft wheel, so as to obviate
any jumping out of gear at the commencement of winding. There is some
tendency towards this unsteadiness of driving in the early part of the
outward run, and it is desirable to lock the Mendoza lever in position.
[Illustration: FIGS. 174 AND 175. J.N.]
[Illustration: FIG. 176.]
(352) Messrs. John Hetherington and Sons employ a special device
by which this difficulty is overcome. The mule, as made by
them—arranged to be driven with the rim shaft transversely, instead
of longitudinally, placed in the headstock—is illustrated in Fig. 176
in longitudinal elevation, and in Fig. 177 in back view. Both views
show the method of driving quite clearly. On the outward end of the
Mendoza weight a pin is fixed which takes into a fork formed at the
upper end of a vertical lever. The fork is shaped with a shoulder or
recess, below which the pin referred to can slip when desired to lock
the Mendoza in position. A small ear is formed on the vertical lever,
through which a set screw is passed, the point of which comes in
contact with the end of a horizontal lever centred on a pin fixed in
the headstock. The last named lever has a long tail extending outwards
toward the carriage. When the carriage comes up to the back stops and
the Mendoza lever falls, putting the driving pinion into gear with the
back shaft wheel, the long tail of the horizontal lever is raised,
and the effect is that the pin in the Mendoza weight passes under
the shoulder of the fork in the vertical catch lever, and so firmly
holds the Mendoza lever down. As the latter carries the driving wheel,
the pinion is kept firmly in gear, and the effective driving of the
carriage is obtained. As soon as the carriage has run out a little—by
which time it has gained momentum—the horizontal lever is released,
and its long end falls, thus freeing the catch or pin in the Mendoza.
Sometimes the minder, in cleaning, runs out the carriage a little and
then changes the cam, without freeing the horizontal or locking lever.
If afterwards the mule is started the carriage endeavours to run in,
although the back shaft wheel and its driving pinion are in gear. This
leads to breakages, and in order to avoid these, Messrs. Hetherington
have arranged a small relieving lever, coupled to the long lever, so
that any motion of the latter causes the relieving lever to act and
free the Mendoza catch pin, without reference to the position of the
horizontal locking lever. This mule is arranged with the extra band
for driving the taking-in side shaft =D= referred to in paragraph 286.
The band =E= is driven from the counter shaft =R=, and passes round a
double grooved pulley on =D=. It is kept in tension by the pulley =F=,
carried by a frame which can be moved inwards by the quadrant rack =G=
with which a worm gears. The remaining reference letters indicate the
same parts as in the other illustrations.
[Illustration: FIG. 177.]
[Illustration: FIG. 178.]
(353) It was shown that to perfect the action of winding at the nose
of the cop it is customary to deflect the chain by means of a nose
peg. A motion based upon the principle of the deflection of the chain,
but in which that object is attained in a different fashion, is shown
in Fig. 178 in side elevation, and in Fig. 179 in enlarged detail.
This is Dobson and Hardman’s patent, and is made by Messrs. Dobson and
Barlow. Two main objects have been aimed at. These are the control of
the winding from the faller—so that the relation of the two will be
strictly maintained—and the deflection of the chain by a pull from
below instead of a push from above. On the faller shaft a tappet is
fixed, to which is jointed a lever =J= with an arm or finger =K=
secured to it. A bracket =H= is attached to the quadrant arm a few
inches from its centre, and its outer edge =H^{1}= is formed into a
rack with which two catches engage. These are carried by a lever =G=,
which is hung on a pin in the upper part of the bracket =H=. =G= has
a projecting shoulder at its outer end, to which is fastened one end
of the chain =E= passing over the pulley =F=, and having its other
end attached to the lower end of the link =C=. The winding chain =B=
is also attached to the link =C=. The lever =G= is formed with an arm
=G^{1}=, to which is jointed a double tumbler =I=, each part of which
is free to move as required. A projection is cast on =I=, which causes
it to rest on =G= when in its normal position. This mechanism acts in
the following manner: When a set of cops is begun the lever =G= is at
its lowest position relatively to the quadrant rack =H^{1}=, and the
winding chain =B= and link =C= are then almost straight. At the end of
each stretch the finger =K= comes into contact with the lower part of
=I=, which is raised to allow =K= to pass. When the inward run begins
=K= causes the projection on =I= to press upon the lever =G= and raise
it if the pressure is maintained a sufficient time. Whether this is so
or not is determined solely by the vertical position of =J=, which,
in turn, is regulated from the winding faller. If the latter is not
substantially raised from stretch to stretch the position of =G= in
like manner remains unaltered. If this is not the case =G= is a little
lifted, and the chain =E= is thus drawn forward a little over the
pulley =F=. The result is that a pull is exercised on the link =C=,
which is drawn down so that it and the chain =B= no longer represent
a straight line. This is equivalent to shortening the chain =B=, and
the result is that the necessary acceleration of the winding drum is
effected. The chief feature of this motion is the regulation which is
obtained from the faller, the position of which fixes the amount of
extra _pull_ put on the drum. However slowly the building proceeds the
necessary acceleration is made in exact proportion.
[Illustration: FIG. 179. J.N.]
(354) In the description of the governing motion, given in paragraph
339, it was shown that the rotation of the screw in the quadrant arm is
made during the inward run of the carriage. There are some objections
made to this procedure on the ground of the extra tension put on the
yarn in the early part of winding, which is of some moment when fine
or tender yarns are being spun. In Fig. 180 a side view is given of a
motion made by Messrs. Dobson and Barlow, which is designed to obviate
the necessity for altering the screw during the inward run, and provide
means by which it can be made during the outward run. In lieu of the
ordinary grooved pulley on the quadrant axis, a toothed wheel =U= is
used, with which a toothed rack =R= can engage under circumstances
presently to be described. The rack =R= is carried by a sliding frame
=S=, which is fixed upon a longitudinal rod =T=, extending backwards
in the headstock, and carried by brackets fastened to the floor. The
rack is fitted at one end with an inclined foot, and at the other with
a spring, which prevents too deep an engagement of the rack and wheel.
The rack passes—during its outward stroke—over a frame fastened to the
headstock, in which is a screw =X= on which is threaded the sliding
stop =W=. The pitch of the screw thread is varied to correspond with
the thread in the quadrant arm =Q=, and the screw is rotated by a
ratchet wheel, with which a pawl, oscillated by a finger, engages. At
the point =I= a loose tongue is hinged, which at the end of the stroke
of the frame engages with the nut =W=. On the winding faller a sector
=Y= is fixed, in which a stud, formed with two portions of different
diameters, is bolted. On the counter faller a sector =Z= is fastened,
carrying a screwed staple, to which is secured one end of a chain,
indicated by dotted lines. The chain passes round the bowl =R= at the
upper end of the pendant lever =O=, guided in brackets at the front of
the carriage. The loose end of the chain is formed into a loop, which
can be slipped on to either of the surfaces of the bowl in the sector
=Y=. A hinged finger =L= is carried by a bracket on the rod =T=, and
has a little range of movement in a circular direction.
(355) In beginning a set of cops the stop =W= is turned back to its
proper position, which is determined by the size of the cop about to
be spun. The frame =S= is then pushed forward as much as possible, and
the chain is slipped on to the smaller portion of the bowl in =Y=. This
allows the pendant =O= to fall a little, and its height subsequently is
regulated strictly by the position of the fallers. During the outward
run the horizontal arm =P=, which forms part of the pendant =O=,
engages with the vertical projection on the frame =S= and causes it
to move forward. The rack =R= being raised engages with the wheel =U=
and rotates it, this movement being consequently communicated to the
quadrant nut. Thus the latter is put into position for action during
the next period of winding and any straining of the yarn is avoided.
As the stroke of the rack is continued, the tongue =I= engages with
the nut and causes the rack to drop out of gear with the pinion, and
any further movement of the quadrant nut is avoided. It has been shown
that the traverse of the latter is gradually diminished as the cop is
built, and, in like manner, the inward motion of the stop =W= causes
the engagement of the rack and pinion to be limited. This is a sort of
“trip” motion very familiar to students of steam engine practice, and
is well applied in this case. The slide =S= is drawn back into position
by the engagement of the lower end of the pendant =O= with the finger
=L=. A slight contact at first between these becomes a firm one by
the backward movement of the finger when pressed upon by the pendant
=O=, but it will be obvious that, if the latter is too high to move
the finger =L=, the rack will remain untraversed until a sufficient
depression of =O= takes place. It only remains to be said that once the
nut =W= has been set at the beginning of winding, all that is required
is for the minder to slip the loop of the chain on the right portion
of the bowl in =Y=, and the motion acts automatically until winding is
finished.
(356) A somewhat similar attachment has been recently introduced in
France, and is the invention of Mons. Dubs. The author is informed by
a trustworthy mechanician that the motion acts perfectly throughout
winding, and it may, therefore, be well to give a brief description
of it. As in the motion of Messrs. Dobson and Barlow, the regulation
of the nut takes place during the outward run, and it is unnecessary
to again detail the reasons for this course. The chief operating part
of the mechanism is the rack finger =A=—shown in its position when
in gear—which is hinged on a vertical rod or plunger =K=, sustained
in a frame or bearing =S= fastened to the carriage. Referring to
Fig. 181, the whole of the apparatus moves with the carriage and is
self-contained. Attached to the faller is a connecting rod or link =B=,
which is coupled to a hinged lever =O= formed at its outer end with
a toothed rack or quadrant finely pitched. With this rack, which has
two sets of stepped teeth, two detent catches =H= engage. The lever
=O= is hinged to a plunger =L=, which has at its lower end a screwed
shank fixed to a plate =F= also secured in the same manner to the
plunger =K=. The inner end of the rack lever =A= has a hanging piece
=D= which can engage with a catch =E= on the plate =F=, but which in
the view is shown out of gear. The downward motion of the inner end of
=A= is regulated by the stop screw =R=, and it is coupled by the chain
=C= to the counter faller. The spring =M= constantly presses the inner
end of =A= down, tending to raise the rack. When the various parts are
adjusted the parts =F K= and =L= move together and simultaneously with
the lever =O=.
[Illustration: FIG. 180. J.N.]
(357) The action of this mechanism is as follows: Assuming that the
inward run of the carriage is nearing completion, the lever =G=
engages with a stop or bracket fixed to the floor, which causes =D=
to fall out of gear with the catch =E=. This leaves the plate =F= and
all its connections to the control of the chain =C= and the counter
faller. When the faller locks it raises the rod =B= and the lever
=O=, which is then held in position by the detent catches =H=. During
the first inward run =O= is lifted to its highest point, which, of
course, affects all the parts attached to it. Just before the end of
each stretch the catches =H= are released, so that the whole of the
subsequent regulation depends on the counter faller. As the locking
point of the winding faller wire is gradually raised the elevation of
the fork at the upper end of =K=—which by reason of the connection
of the plate =F= with the lever =O= always takes place—occurs at a
gradually lower point throughout building. The effect is that when =D=
is released, as described, an elevation of the rack =A= takes place if
needed. If not, =D= falls over the catch =E= as the carriage begins to
run out and thus locks it, preventing the rack =A= from rising. If,
however, the tension on the yarn at the end of winding is such that the
counter faller is depressed, the catch =D= cannot recover its position.
The end of the rack lever consequently falls on to the stop screw
=R=, and the rack is raised into contact with a wheel on the quadrant
axis formed with teeth of a similar shape. Thus the screw is given a
turn while the carriage is running out, and the nut is in the correct
position for winding the next length.
(358) Quite recently Messrs. Curtis, Sons and Co. have constructed a
mule in which the cam shaft, as an instrument for making the “changes,”
is entirely done away with. A side elevation of the mechanism for
effecting this is shown in Fig. 182, and a plan of the same in Fig.
183. The back shaft clutch =F= is formed so that its driving half
slides, this being controlled by the action of a lever =L=, connected,
as shown, at two points to the rods =R M=. The taking-in friction
is placed horizontally, and is controlled by the vertical lever =H=
connected with the sliding rod =R=. The lever =F^{1}=, by which the
back shaft clutch is disengaged, is coupled by the link going across
the carriage—shown in Fig. 183—to the roller clutch box, so that the
engagement or disengagement of the roller clutch box is simultaneous
with the attachment or detachment of the roller gear. The mechanism for
actuating these parts is based upon the principle of the push and pull
of spiral springs, a partial application of which was shown in the case
of the backing-off rod. On the axle of the quadrant a short arm =S= is
fixed, which is coupled with the rocking lever =T=, connected to the
sliding boss on the rod =M=. Two springs =M^{1} M^{2}= are threaded on
the shaft, and are placed respectively between the sliding boss and
stop hoops fixed on the shaft. The rod =M= is coupled at the back to
the lever =L=, the function of which is, as indicated, to actuate the
back shaft clutch. At the front end of the rod =M= a catch lever =Q=
is fixed, which detains it as the carriage is running out. When this
happens, the spring =M^{1}= is compressed by the oscillation of the
quadrant axle acting through the crank =S= and its connections, the
other spring =M^{2}= being then out of compression. As soon as the
end of the outward run is reached a boss on the counter faller shaft
=B^{1}= comes in contact with the underside of the catch lever =Q= and
raises it, thus freeing the rod =M=. The spring =M^{1}= is thus free
to extend, and, acting upon the lever =L=, disengages the back shaft
and roller clutches. This accounts for one part of the changes; and
while it is taking place a catch lever =O=, which had previously been
raised, is lowered. When the inward run of the carriage is made by the
operation of the same parts the spring =M^{2}= is compressed. On the
arrival of the carriage at the roller beam the lever =O= is tripped by
a boss on the faller shaft =B=, allowing the spring =M^{2}= to extend
and re-engage the two clutches named.
(359) The taking-in or scroll shaft is operated from the rod =R=, which
is fitted with one spring only at its back end. This is compressed by
the intervention of a second lever, fastened on the same shaft on which
the rocking lever =T= oscillates, the compression taking place during
the outward run of the carriage. The spring is held in compression by a
latch =P=, which engages with a lug on the rod =R=. When the carriage
runs in, a boss on the faller shaft releases the latch, and the
extension of the spring disengages the taking-in friction clutch. The
latter is put into gear by the locking of the faller in the ordinary
manner, and is held in gear until the latches =O= and =P= are tripped
in the manner described. The spring =R= presses on a collar carried
by the lever =H=, and the releasing of the friction is aided by the
lever =L=, which comes against the head of =H= when the spring =M^{2}=
is extended. The levers =H= and =L= are so arranged that they cannot
both act together, so that the two motions of taking-in and drawing-out
cannot be in action at the same time.
[Illustration: FIG. 181. J.N.]
(360) The angle of the spindle relatively to the vertical line is such
as is necessary to suit the material being spun, but there is another
feature which it is necessary to mention. As the point of the spindle
moves in a horizontal plane, it is obvious that the yarn will pass on
to it from the rollers at an angle varying with its distance from them.
That is to say, the angle formed by the yarn, in passing on to the
spindle, will be more acute when the carriage is near to the rollers
than it will be when it is further away. This has a little influence
upon the problem of spinning, and an arrangement exhibited at the
Manchester Jubilee Exhibition, applied to Messrs. Asa Lees and Co.’s
mule, is shown in Fig. 184. In this case there are two carriage slips
instead of only one, and these are inclined so as to compensate for
the difference in angle. On one of the slips =A= the front carriage
runner =D= travels, and on the other the back one =C=. The result
is that the inclination of the spindles is slowly altered, with the
result that the angle formed by the yarn and the spindle in each case,
is nearly the same in all positions. This device worked well, but the
difficulty existing does not appear to be great enough to lead to any
wide adoption of it.
[Illustration: FIGS. 182 AND 183. J.N.]
(361) Having thus described in detail the construction and principles
of the mule, it is only necessary to say a few words on the subject
of its application to the spinning of the finer counts, which require
specially delicate treatment. It is found necessary to fit a few
special attachments which are supplementary to the ordinary mechanism
employed. In dealing with fine yarns the rollers are stopped a little
before the carriage has completed its outward run, and this results in
the yarn being a little stretched. A more important result, however,
is that if there be any unevenness in the diameter of the yarn, the
twist speedily runs into the thin places, which become hardened, and
do not easily elongate or draw. The thicker places remaining untwisted
are, therefore, drawn down until the full twist runs into them also.
This supplementary twisting and drawing is called “jacking,” and
its amount varies, of course, with the staple of the cotton being
spun, the further movement of the carriage being sometimes as much as
five inches. In order to permit the jacking to be effective, it is
the custom to put into the yarn very little twist before the roller
delivery ceases, after which it is rapidly introduced. This tends to
shorten the yarn and puts it in such a state of tension, that unless
relieved, it would break. There are two methods of obviating this
difficulty. The first is to move the carriage in a little during the
period of twisting, and the other to cause the rollers to deliver a
short length of yarn. The latter is now the most usual method, and
by the adoption of a special engaging motion, the amount delivered
can be regulated at will. When long stapled cotton is being spun, it
is the practice to cause the rollers to deliver a little yarn during
the inward run, while winding is going on. The amount varies, but is
about three inches, so that only 60 inches is wound on the spindle
during each inward run. Messrs. Platt Brothers and Co. make a very good
fine spinning mule with a number of well thought out motions of great
ingenuity, a full description of which will be found in the Proceedings
of the Institution of Mechanical Engineers, 1880, pages 516 to 527.
[Illustration: FIG. 184. J.N.]
(362) Mr. Richard Threlfall of Bolton has devoted himself to the
construction of fine spinning mules, and has produced a self-acting
machine, which is capable of spinning the highest counts. With a brief
description of it as made by him, the present treatment of this machine
must be closed. In the Threlfall mule the roller delivery after jacking
is effected by a short shaft on which is a catch box, the outer surface
of which constitutes a cam course, which is revolved from the twist
shaft. On this cam shaft is the first of a train of wheels, which
gear up to the roller, and the first wheel has motion given to it by
a ratchet and pawl, the movement of the latter being controlled by
the throw of the cam. The cam can be set so as to give a whole turn
to the rollers, or only one flute, and by means of changes in the
train of wheels further regulation can be made. The copping rail is
specially constructed, so as to enable short cops of any shape to be
easily built. The fallers are arranged so as to be very sensitive in
action. The action of the quadrant is aided by a special contrivance
consisting of a narrow pulley placed alongside the loose backing-off
pulley, but fast on the shaft. Connected to the strap guide is a
lever which is coupled to a rod suitably carried in brackets, and on
which is a regulating screw and nut. This regulation is provided so
that the passage of the strap on to the narrow pulley is effected as
desired. The strap is prevented from traversing from the loose pulley
by a catch, and the release of the latter is effected by a finger on a
bracket fastened to the carriage square. When the latter runs in the
finger pushes over a tumbler holding the catch in position and releases
the latter. The weight of the parts then throws the strap over on to
the fast narrow pulley, and the winding is thus accelerated. By fixing
the finger and setting the adjusting screw, this motion may be brought
into play at any desired moment. On the faller shaft is a bracket, to
the outer edge of which is attached by a bolt or screw a grooved cam
surface. To this is attached a cord actuated by the governor motion. By
suitably setting the cam, winding is effected during each inward run
with equal tension. A brake is applied to the faller shaft, consisting
of a lever fastened to the carriage, one end of which engages with
an inclined plane, and the other end has a cord attached passing
over a pulley on the faller shaft. By tightening the band the faller
is held perfectly steady. The combination of the last three motions
effectually prevents snarls. A roller delivery motion is added, and the
most perfect adjustment of the whole of the movements is provided. The
spindles revolve at two speeds, the final or twisting velocity being
about 8,000 revolutions per minute.
(363) Such is a description of the most intricate machine in the whole
range of textile mechanics, which, although threatened more than once
with extinction, is yet more largely used to-day than at any previous
time. On it yarn of varying qualities can be spun, either soft or hard
twisted. The yarn which is used for warp purposes is more commonly
known as twist, and that employed for weft is known by that name. Weft
yarn, as will be shown at the end of the next chapter, is always more
softly twisted than warp yarn, and the mule spindles revolve in the
opposite direction to that employed when the latter is spun. About
the question of twists and the system of the arrangement of draughts
throughout the whole process of spinning, a few words will be said in
concluding the next chapter.
(364) The mule is used in a modified form to produce “doubled”
warps-that is, two strands of yarn twisted together. When so employed,
the machine is known as a “twiner,” and is constructed with a low
creel. With the necessary alterations to suit the circumstances
peculiar to the case, the machine is largely employed in certain
districts. In its main features, however, it resembles the mule, and
does not require a detailed description. Another modified form is used
for spinning yarns made from waste, being nearly identical with the
machine as employed in spinning fine worsted yarns. The student who is
interested in this subject will find a description of the woollen mule
in “Spinning Woollen and Worsted,” by Mr. W. S. Bright McLaren, M.A.
(365) A table is appended of actual productions from Messrs. John
Hetherington and Sons’ mule. These are given from 74 machines for the
ordinary working week of 56-1/2 hours. A great variety of counts are
included, all of which were being spun at the same time. An additional
table is given of productions from Messrs. Platt Brothers and Co.’s
mule. An explanation of the value of the hank is appended to the next
chapter.
TABLE 2.
ACTUAL PRODUCTIONS IN A WORKING WEEK OF 56-1/2 HOURS, FROM MESSRS. JOHN
HETHERINGTON AND SON’S MULES.
+--------+----------+---------+-----------+
| No. of | Hanks. | Counts. | Hanks per |
| Mule. | | | Spindle. |
+--------+----------+---------+-----------+
| 2 | 77,250 | 39 | 31·14 |
| 4 | 70,750 | 43 | 28·52 |
| 6 | 71,000 | 43 | 28·62 |
| 8 | 75,500 | 41 | 30·44 |
| 10 | 65,750 | 32 | 32·42 |
| 12 | 68,750 | 28 | 33·90 |
| 14 | 61,750 | 36 | 30·44 |
| 16 | 71,750 | 45 | 28·73 |
| 18 | 69,750 | 45 | 27·94 |
| 20 | 72,250 | 45 | 28·94 |
| 22 | 71,750 | 45 | 28·73 |
| 24 | 71,000 | 45 | 28·43 |
| 26 | 71,250 | 45 | 28·53 |
| 28 | 71,250 | 45 | 28·53 |
| 30 | 72,250 | 45 | 28·93 |
| 32 | 73,000 | 42 | 29·23 |
| 34 | 72,500 | 42 | 29·03 |
| 36 | 61,500 | 36 | 29·97 |
| 38 | 66,750 | 32 | 32·52 |
| 40 | 62,000 | 38 | 30·21 |
| 42 | 58,500 | 38 | 28·50 |
| 44 | 62,750 | 36 | 30·57 |
| 46 | 62,250 | 38 | 30·33 |
| 48 | 63,250 | 36 | 30·82 |
| 50 | 60,250 | 38} | 29·35 |
| | | 33} | |
| 52 | 64,750 | 34 | 31·55 |
| 54 | 65,750 | 36 | 32·03 |
| 56 | 65,000 | 40 | 30·52 |
| 58 | 61,750 | 40 | 29·91 |
| 60 | 61,000 | 42 | 29·55 |
| 62 | 60,000 | 42 | 29·06 |
| 64 | 63,000 | 40 | 30·52 |
| 66 | 61,500 | 40 | 29·79 |
| 68 | 61,500 | 42 | 29·79 |
| 70 | 61,250 | 42 | 29·67 |
| 72 | 59,750 | 42 | 28·94 |
| 74 | 65,750 | 40 | 31·85 |
+--------+----------+---------+-----------+
| Total Weight, 59,920-1/2 lbs. |
| Average Counts, 39·53. |
| Average Hanks per Spindle, 29·88. |
+-----------------------------------------+
TABLE 3.
ACTUAL PRODUCTIONS IN A WEEK OF 56-1/2 HOURS OF TWIST AND WEFT YARNS
FROM MESSRS. PLATT BROTHERS AND CO’S. MULES.
+-----------------------------------+
| TWIST. |
+-------------+----------+----------+
| No. of | Counts | Hanks |
| Spindles in | spun. | per |
| each Mule. | | Spindle. |
+-------------+----------+----------+
| 1044 | 30’s | 32 |
| „ | 32’s | 31·5 |
| „ | 33’s | 30·65 |
| „ | 24’s | 30 |
| „ | 50’s | 28 |
| „ | 54’s | 27 |
+-------------+----------+----------+
+-----------------------------------+
| WEFT. |
+-------------+----------+----------+
| No. of | Counts | Hanks |
| Spindles in | spun. | per |
| each Mule. | | Spindle. |
+-------------+----------+----------+
| 1280 | 28’s | 33·81 |
| „ | 29’s | 34 |
| „ | 34’s | 31·85 |
| „ | 36’s | 31 |
| „ | 38’s | 30·46 |
| „ | 40’s | 30 |
| „ | 46’s | 29 |
+-------------+----------+----------+
NOTE.--The production of any mule varies of course with the class of
cotton used, the amount of twist required, and the length of mules; but
the figures given in the tables are, in each case, figures of actual
productions.