[Footnote: A recent lecture before the Society of Arts, London.]
By JOHN W. URQUHART.
The distinct improvements in sewing machinery to which I would invite your
attention this evening have reference more particularly to the results of
inventive effort within the past ten years. But although marked development
in the machines has occurred in so short a time, it may be taken for
granted that those advances are but the accumulated results of many years'
prior invention and experience of stitching appliances.
The history of the sewing machine, and the decision of the great question,
Who invented an apparatus that would unite fabrics by stitches? do not at
present concern us. Many sources of information are open to those who would
decide that extremely involved problem. But whether the production of the
first device of this kind be claimed for England or for America, it is
quite certain that no one man invented the perfect machine, and that those
fine specimens of sewing apparatus shown here to-night embody the labors of
many earnest workers, both in Europe and America.
Most of us are familiar with the arrangements of an ordinary lock stitch
machine, and an able paper by Mr. Edwin P. Alexander, embracing not only a
good account of its history, but most of the elements of the earlier
machines, has already (April 5, 1863), been read before you. This, and
sundry descriptions of such apparatus in the engineering papers, confine my
remarks to the more recent improvements in three great classes of machines.
These are, briefly, plain sewing machines; sewing machines as used in
factories, where they are moved by steam power; and special sewing
machines, embracing many interesting forms, only recently introduced. We
have thus to consider, in the first place, the general efficiency of the
machine as a plain stitcher. Secondly, its adaptability to high rates of
speed, and the provision that has been made to withstand such velocities
for a reasonable time. And, thirdly, the apparatus and means employed to
effect the controlling of the motive power when applied to the machines.
To deal with the subject in this way must, I fear, involve a good deal of
technical description; and I hope to be pardoned if in attempting to
elucidate the more important devices, use must be made of words but seldom
heard outside of a machinists' workshop.
It appears scarcely necessary to premise that the sewing machine of twenty
years ago has almost faded away, save, perhaps, in general exterior
appearance; that the bell crank arms, the heart cams, the weaver's
shuttles, the spring "take ups," rectangular needle bars, and gear wheels,
have developed into very different devices for performing the various
functions of those several parts.
The shuttle is perhaps the most important part of a lock stitch machine.
But what is a shuttle? So many devices for performing the functions of the
early weaver's shuttle have been introduced of late, that the word shuttle,
if it be used at all, must not be accepted as meaning "to shoot." We have
vibrating shuttles, which are, strictly speaking, the only surviving
representatives of the weaver's shuttle in these new orders of machines;
and stationary shuttles, oscillating shuttles, and revolving shuttles,
besides the earlier rotating hook, in several new forms, difficult to name.
But the general acceptation of the word shuttle, as indicating those
devices that pass bodily through the loop of upper thread, is, I venture to
think, sufficiently correct.
Many changes have been effected in the form, size, and movements of the
shuttle, and we may profitably inquire into the causes that have induced
manufacturers to abandon the earlier forms. The long, weaver's kind of
shuttle, originally used by Howe and Singer, had many drawbacks. Mr. A.B.
Wilson's ingenious device, the lock stitch rotating hook, was not free from
corresponding faults. The removal of these in both has led to the adoption
of an entirely new class of both shuttles and revolving hooks. It is well
known that the lock stitch is formed by the crossing of two threads, one of
which lies over, and the other under, the cloth to be sewn. This crossing
point, to insure integrity of the stitch, must occur as nearly as possible
in the middle of the thickness of the fabric. The crossing must also be
effected while a certain strain, called tension, is imposed upon both
threads. If the tension of one thread should outweigh that of the other,
the locking point becomes displaced. If the tension be insignificant, the
stitches will be loose. If the tension should vary, as in the long shuttle,
there will occur faulty points in the seam.
In the earlier rotating hook the tension depended upon the friction
developed between the spool and the hook. This tension, therefore, varied
in proportion to the speed of the latter, and could never be constant. This
was quite apart from the frictional resistance offered to the upper thread
in passing over the cavity of the hook.
In the shuttle the tension was obtained by threading through holes in the
shell, or beneath a tension plate, as in Howe's machine. This tension, so
long as the reel ran between spring centers, was never constant. The
variation was chiefly due to the angular strain set up when unwinding from
the reel. This strain varied according to the point of unwinding. It was
light in the middle of the reel and heavy at either extremity. These
drawbacks caused immense anxiety to the first makers of sewing machines,
and numerous attempts to overcome them led to little improvement. With
reference to high rates of speed, the older shuttle, requiring a long and
noisy reciprocation, had its disadvantages.
The only effective remedy for these drawbacks was a radical one. It was
necessary to substitute depth of reel for length. Hence, several attempts
have been made to construct disk or ring shuttles. Many forms of those have
been tried. They all depend upon the principle of coiling up the thread in
a vertical plane, rather than in horizontal spirals. Some makers placed the
disk in a horizontal plane, and caused it to revolve. Nothing could be
worse, as will be seen, if we follow the course the enveloping loop must
take in encircling such a shuttle. But a complete solution of the
difficulty of employing a ring shuttle has been achieved in the oscillating
form, invented by Mr. Phil. Diehl, and known as Singer's (Fig. 1). A short
examination of it may profitably engage your attention. The shuttle itself
is sufficiently well known, but certain features of it, and to which it
owes its efficiency, appear to call for some explanation. Its introduction
dates back some years, during which time it has undergone certain
modifications.
[Illustration: FIG. 1.]
It consists of a thick disk bobbin of thread, _h_, fitting loosely in a
case constructed in the form of a bivalve, _a_ and _d_. This case is
furnished with a long beak, usually forming a continuation of the
periphery. The beak is intended to enter and detain the loops of upper
thread, and lead them so that they ultimately envelop the shuttle, a motion
of the thread which is chiefly due to the oscillation of the shuttle in a
vertical plane. The oscillating movement is to the extent of 180 degs. of
the circle, which suffices to cast the loops freely over the shuttle. The
center of oscillation is not coincident with the center of the shuttle; but
it is nearly so with the periphery of the thread reel, and exactly
coincides with the point where the under thread is drawn from the shuttle,
_g_. The shuttle thread is thus entirely freed from any tendency to twist,
an objection frequently urged against circular or revolving shuttles. It
will be observed, also, that the body of the shuttle is extremely narrow.
Bulging of the thread loops to one side or the other is thus obviated.
But the long beak in this description of shuttle serves an important
purpose other than that of seizing the upper thread loops, otherwise a very
short beak would be preferable. It adds so much to the efficiency of the
machine that a little further explanation of it appears essential. In the
old fashioned machines the thread required to envelop the shuttle was
dragged downward through the cloth, while the needle still remained in the
fabric. This necessitated the use of large needles with deep side channels,
to enable the thread to run freely, and as a consequence the punctures that
had to be made in the fabric were unnecessarily large, and could not in any
case be entirely filled by the thread, a condition which is now recognized
as essential in linen stitching and for waterproof boots.
The long beak in both shuttles and hooks offers an immediate solution of
the old difficulty experienced with long shuttles. When the needle begins
to rise, the shuttle commences to oscillate, through the loop, the motions
so coinciding that the long beak, c, merely detains the loop until the eye
of the needle has ascended above the cloth; then, and then only, does the
envelopment of the shuttle commence, and the thread required for it flows
downward through the puncture. The envelopment is completed before the
needle has attained its highest point, and the consequent loose thread is
immediately pulled up by a lever, called a positive take-up, before the
needle begins to descend for a fresh stitch. In this way little or no
movement of the thread is required in the cloth while the puncture made is
occupied by the needle. The result is the capability of such apparatus to
work with an incredibly fine needle--indeed, so fine as to be no thicker
than the incompressed thread itself. This would have been considered quite
impossible of accomplishment by our earlier machine makers. The advantage
thereby gained in stitching linen goods, and in sewing leather, where every
puncture of the needle should be quite filled by the thread, is at once
apparent. Indeed, a rubber or leather sack, stitched in this way, will
contain water without leakage--a very extreme test.
_Revolving Shuttles_.--The class of shuttles known as revolving or
rotating, and which really consist of a combination of the disk shuttle and
the earlier rotating hook of Wilson, have been under trial by several
makers for many years. If, for example, the oscillating shuttle we have
just examined were to complete its circular movement, it would constitute a
revolving shuttle, but would not be quite similar to those devices now
known as such. The most remarkable device of this kind yet introduced is to
be found in Wheeler & Wilson's machine known as No. 10 D, and invented by
Mr. Dials last year. It consists, in fact, of a detached hook, and its
inventor declines to class it with shuttles at all, styling it a detached
hook. It consists of an exterior shell or skeleton of steel, capable of
rotation in an annular raceway. Its detachment from the axis forms a
striking exception to the general construction of interlocking apparatus in
this company's machines. Under the beak of this curious device is found an
oblong recess, into which fits loosely a carrier or driver, rotating with a
differential or variable motion. The space between the carrier and the
sides of the recess is sufficient to permit the free passage of the thread
in encircling the shuttle, and the differential movement ingeniously
releases the contact between the hook and carrier. The skeleton of this
device is only one-sided, and does not really carry its bobbin in the
course of its revolution. The bobbin is placed in a cup-like holder, which
lies within the shuttle or hook body, and is retained in position by a
latch hinged to the bed of the machine. The cup and bobbin are prevented
from partaking of the rotatory movement by a steel spur projecting from the
cup, and fitting loosely into a notch in the latch. Tension upon the under
thread is obtained by passing it under a tension plate upon the bobbin cup.
Twisting of the thread is by these means entirely obviated. In this
apparatus, the disk-like appearance of the bobbin is partially lost in its
considerable breadth, and there is thus a distinct departure from the lines
of the ring shuttles before mentioned. The diagrams exhibit the hook in
several positions during its revolution, and the position of the threads
corresponding thereto.
[Illustration: FIG. 2]
_Fixed Rotating Hooks_.--Wilson's rotating hook for lock stitch machines,
and Gribbs' hook for single thread machines, are both well known. In the
year 1872, the Wheeler & Wilson company introduced a new hook, forming an
improvement upon Wilson's original device (Fig. 3). Its chief peculiarity
consists in the extension of the termination of the periphery, forming a
long tail piece, quite overlapping the point, and serving as a guard, both
to keep off the bobbin thread and to prevent collision between bobbin and
needle.
[Illustration: FIG. 3.]
This improved class of hooks are provided with a much deeper cavity than
those first introduced, an arrangement permitting of the employment of a
more commodious bobbin, which is generally covered by a cap, as in the
revolving shuttle, but free to revolve. In some cases the cap carries a
tension plate preventing its revolution with the hook. But beyond these
improvements on Wilson's original device, the utility of the hook mainly
depends upon two things quite apart from the hook itself. These are the
dispensing with the old fashioned check brush and the use of a positive
take-up.
Thus, in the original machine, the stitch was pulled up by the succeeding
revolution of the hook. For while one revolution sufficed to cast it over
the spool, a second turn was requisite to complete the stitch. In this way,
to make a first stitch with such an apparatus required two turns of the
rotating hook. The improvements mentioned enable the machine to complete a
stitch with one turn of the hook--an important step in advance, when we
consider that by the old method each length of slack thread must be
tightened up solely through the fabric and the needle eye. But this
particular arrangement bears so much upon the introduction of the positive
take-up itself that further reference to it must be reserved until that
device has been described.
_Simple Thread Hooks_.--The best known of these is Willcox & Gibbs. It has
been so often described, that no further reference to it may be made. It
continues to make the same excellent twisted stitch as it produced
twenty-five years ago.
_Of Vibrating Shuttles_.--These are shuttles of the long description,
moving in a segment of a circle. There are several varieties. The most
novel machine of this kind is the vibrating shuttle machine just produced
by the Singer Manufacturing Company. In this case the shuttle itself
consists of a steel tube, into the open end of which the wound reel is
dropped, and is free to revolve quite loosely. Variation of tension is thus
obviated in a very simple manner. The chief point of interest in the
machine is undoubtedly the means employed in transferring the motion from
the main shaft to the underneath parts, an arrangement as ingenious and
effective as any device ever introduced into stitching mechanism. It is the
invention of Mr. Robert Whitehall, and consists of a vertical rocking shaft
situated in the arm of the machine Motion is imparted to it by means of an
elbow formed upon the main shaft acting upon two arms, called wipers,
projecting from the rocking shaft, the angle formed by the arms exactly
coinciding with that of the elbow in its revolution. This admirable motion
will no doubt attract much attention from mechanists and engineers.
_The Lock Stitch from Two Reels_.--In the early days of the sewing machine,
the makers of it often met with the question, "Why do you use a shuttle at
all? Can you not invent a method of working from a reel direct?" The
questioner generally means a reel placed upon a pin, just as the upper reel
is placed. The reply to such a query is, of course, that to produce the
lock stitch in that way is impossible--as indeed it is.
But many ingenious machinists have pondered long over the problem, and
several clever contrivances have been invented with a view to its solution.
It may scarcely be necessary to say that the best manufacturers of sewing
machines have conducted experiments with the same object in view, and the
result has always been a return to the shuttle, with its steel bobbins.
Why is this, and how is it that a very big shuttle cannot be used, large
enough, indeed, to accommodate any bobbin within itself? The answer is very
simple. It has been done over and over again.
Since the whole bulk of the under thread must pass through the loop of the
upper one, it, is quite clear that the size of that loop must be
proportioned to the bulk of the shuttle. Thus, a small shuttle would,
perhaps, be covered by an inch of thread, while our supposed mammoth
shuttle might require ten times that amount. Now, let us consider that to
sew an inch of thread into lock stitches frequently involves its being
drawn up and down through both needle and fabric twenty times. This means
considerable chafing, and possible injury to the thread.
But if we were to sanction the use of capacious shuttles, ten inches of
thread must undergo this chafing and seesaw treatment, and under the above
conditions every part of the ten inches must pass up and down two hundred
times--treatment that might reasonably be expected to leave little "life"
in the thread. But in spite of this tremendous drawback, there are machines
offered for sale made with such shuttles.
For reasons that I have now pointed out, it is quite clear that a large
shuttle or bobbin is by no means an unmixed advantage. Indeed, the very
best makers of sewing machines have always striven to keep down the bulk of
the shuttle, and in those splendid machines shown here to-night the use of
the small shuttles is conspicuous. It may be contended that small bobbins
frequently require refilling, which is quite true, but the saving of the
thread effected thereby, not to mention that of the machine itself, amply
compensates for the use of small shuttles. Apart from this, however, it is
no longer necessary to wind bobbins at all. Dewhurst & Sons, of Skipton,
and Clark & Co., of Paisley, have produced ready wound "cops" or bobbins of
thread for placing direct into shuttles. Thus no winding of bobbins is
necessary, and indeed the bobbins themselves are dispensed with. I believe
that the slightly increased cost of the thread thus wound is the only
present bar to the extensive introduction of ready wound "cops."
_Of Thread Controllers_.--One of the earliest difficulties encountered by
the maker of a sewing machine was that of effectually controlling the loose
thread after it had been cast off the shuttle. In some machines this slack
thread amounts to six, in others to one or two inches. Howe got over the
difficulty by passing his thread, on its way to the needle, over the upper
extremity of the needle bar--the ascent of the bar, then, sufficed to pull
up the slack. Singer improved upon this by furnishing his machine with a
spring take-up lever, partially controlled by the needle bar.
[Illustration: FIG. 4.]
Wilson, in the Wheeler-Wilson machine, had neither of those arrangements,
but depended upon the succeeding revolution of the hook to draw up the
slack of the preceding stitch. These devices were all far from perfect in
their operation, chiefly because they commenced to act too soon. In each
case the pulling up commenced with the rise of the needle, and the
tightening operation subjected the thread to all the friction of rubbing
its way through both needle eye and fabric. Now, an ideal take-up should
not commence to act until the needle has ascended above the fabric, and one
of the most important steps toward perfection in sewing machines was
undoubtedly attained when such a device was actually invented. In effecting
this, the means employed consists of a differential or variable cam,
rotating with the main shaft. This controls the movements of a lever called
the take-up, pivoted to the machine (Fig. 4). Not only has it been
possible by these means to control the tightening of the stitch, but the
paying out of the thread for enveloping the shuttle also, and both the
paying out and pulling up are actually effected after the needle has
ascended above the cloth. The introduction of the positive take-up, the
first forms of which appeared in 1872, not only simplifies the movements of
the shuttle or hook, but for the first time renders the making of the lock
stitch possible, while the needle has a direct up and down motion. Thus, we
find that in most of the swiftest sewing machines, the needle bar is
actuated by a simple crank pin or eccentric, there being no loop dip or
pause in its motion.
The diagram shows a positive take-up in three positions--at the
commencement of the needle's descent, during the detention of the loop by
the beak, and during the casting off of the loop. The dotted lines indicate
the path of the cam to produce these positions. The intermittent movements
of the take-up have thus led to the abandonment of variable motions in both
needle and shuttle, and particularly so in oscillating shuttle machines.
_Wheeler & Wilson's Variable Motion_.--But while the simple and direct
movement is now preferred for shuttles, both oscillating and rotary, the
revolving hooks of Wheeler & Wilson are provided with a differential
motion, and the way it is effected appears sufficiently interesting to call
for a short description. When the rotating hook has seized the loop of
thread, it makes half a revolution with great rapidity; its speed then
slackens, and becomes very slow for the remaining half a revolution. In the
first machines introduced, this was effected by means of a revolving disk,
having slots in which worked pins attached to the main shaft and hook shaft
respectively.
[Illustration: FIG. 5.]
In the later and more improved machines, the variable device is much
simplified (Fig. 5). The main shaft, leading to the rotating hook, is
separated into two portions, the axis of one portion being placed above
that of the other. A crank pin is attached to each, and these pins are
connected together by a simple link. An examination of the device itself
shows that, while the motion of the main shaft portion is uniform, that of
the hook shaft is alternately accelerated and retarded.
The picture on the screen gives a general view of the No. 10 D machine, in
which these motions are embodied, and showing the position of the positive
take-up affected by those motions, a position which is preferred for very
high speeds in this machine, especially for threads possessing little
elasticity.
_Motions of the Feeder_.--The speed attained by the fastest sewing machines
is due more to the reduction and simplification of the movements than to
any other improvement. Heavy concessions and reactions have been replaced
by direct motions, and cams have been excluded as much as possible. Mr.
A.B. Wilson's famous invention of the four motion feeder depended upon both
gravity and a reacting spring for two motions. Singer improved upon it by
making three of the motions positive, a spring being used for the drop. But
a really positive four motion feeder was long sought by inventors.
Hitherto the reaction of the feeder--that is, its descent and
recession--was generally attained by means of a spring. The drop and ascent
are now effected by means of a separate eccentric in Singer's machine.
Uncertainty of action in the feed, once a cause of much inconvenience, may
now be said to be overcome. A peculiarity of the four motion feeder in
Wheeler & Wilson's machine is an arrangement enabling the operator to feed
in either direction at will.
Not less worthy of note are improvements that have been made in wheel
feeders. The wheel feed was originally much used for cloth sewing machines,
especially in Singer's system. But in recent years the drop or four motion
feeder has entirely superseded it for such purposes. The wheel feed still
holds its own, however, for sewing leather, especially in the "closing" of
boot uppers, in this country. Singer's original wheel feeder was actuated
by a friction shoe riding upon the flange of the wheel. The friction grip,
however, had certain faults, owing to the tendency of the shoe to slip when
the surfaces became covered with oil.
[Illustration: FIG. 6.]
A later form of Howe's machine used a pair of angular clutches, embracing
the flange of the wheel. In both Singer's and Wheeler & Wilson's latest
styles of machines this arrangement is simplified and improved by the use
of a single angle clutch, which is found to work even when the surfaces are
freely oiled (Fig. 6).
Any motion of the free extremity of the lever upon which the biting clutch
is formed binds the latter upon the flange of the wheel, which then
advances so long as the lever continues to move in that direction. When the
stitch is completed, the clutch is allowed to recede, and is pulled back by
a reacting spring. The bite of the clutch is given by the two opposite
corners.
The feed wheel itself is free to revolve in a forward direction, but is
prevented from rocking backward in Singer's machine by an ingenious little
device, recently introduced. It consists of a small steel roller, situated
within the angle formed by an inclined plane and the flange of the wheel,
and constantly pulled into the angle by a spiral spring. Any backward
tendency of the wheel binds the roller more firmly in the angle and stops
the wheel. Former feed wheels were checked by a brake spring or block,
which retarded the motion of the whole machine when heavily adjusted.
_Feeders for Button Hole Sewing Machines_ are almost invariably of the
wheel type, but in this case the cloth is usually carried by a clamping
device, and moved in a pear-shaped path by means of a cam cut in the feed
wheel, as shown in the samples of this wonderful kind of mechanism
exhibited here to-night.
_The Compensating System of Construction_.--Compensation for wear is a part
of the mechanist's art that appears just as essential to him as
compensation for variation of temperature is to a maker of chronometers. In
the construction of sewing machines to be run in factories by power at
their utmost speed, such a system is of the greatest importance. An
effective _system_ of compensation has been eagerly sought by the best
machine makers ever since the introduction of fast speed sewing.
Compensation has been attempted here and there in the machines for many
years, but no sewing apparatus could be said to be so compensated until the
cone compensator came into use, a device which has been taken advantage of
by various makers. Save in the shuttle race itself there is not a part of
the oscillating shuttle machine subject to serious wear that cannot be
instantly adjusted to full motion by the turning of a screw, while wear in
the shuttle race can be compensated for in the usual way. This effective
system depends upon the union of two mathematical forms, long used in
mechanism--the _cone_ and the _screw_. In screw cones we possess a perfect
compensator, and it is surprising that parts of mechanism so hung appear
subject to very little wear. Another advantage, too, is gained by the
introduction of screw cone bearings; the friction is always greatly reduced
by their use. In every case the fine adjustment of the cones is securely
maintained by locknuts (Fig. 7).
[Illustration: FIG. 7.]
But the screw cone system is not the only compensator used in sewing
machinery; where it cannot be easily introduced, other devices have been
employed.
The well known tapering needle bars of former years have been superseded by
cylindrical needle bars. The Wheeler & Wilson Company appear to be the
first who utilized the engineer's shifting box as an antifriction device
for round needle bars. They packed their bars round with felt rings, and
compressed the whole by a screw cap.
In the Singer machines the same excellent device has been adopted, hemp
packing and screw bushes being used (Fig. 8); _f_ and _g_ show the direct
action on the needle bar. This method of forming needle bar bearings,
partially of metal and partially of felt or hemp, has afforded the most
surprising results.
[Illustration: FIG. 8.]
When the bars are of hard or finely polished steel, no perceptible wear can
be detected in them, even after they have been in daily use in factories
for twelve months, whereas bars not so bushed might show considerable wear
in that space of time. The packing, to be effective, should be sufficiently
close to prevent as much as possible friction of the steel with the cast
iron needle bar ways. Lubrication of the steel is insured by keeping the
hemp packing moistened with oil.
Cylindrical needle bars, when combined with an effective system of
brushing, have proved themselves superior to every other form of slide for
lock stitch machines. But their introduction is by no means a thing of
yesterday. They were used freely in sewing machines as far back as 1860,
but were never very successful until united with the lubricating brush.
Some makers go a step further, and elaborate the system by the introduction
of steel brushes, easily renewable.
Every effort is now made to reduce, as much as possible, not only the
extent of movement of the parts in high speed machines, but the weight of
the parts themselves. Indeed, so far has this been carried that, in some of
the Wheeler & Wilson machines now shown, the needle bars consist really of
steel tubes. Small moving parts are made as light as possible, but rigidity
is secured by the free use of strengthening ribs. Many of the parts are of
cast iron, rendered malleable by annealing, and finally casehardened. Such
parts are found to be quite as durable as if made of forged steel, and are,
of course, less costly. As to the automatic tools now used in the
construction of the machines, it may be said that scarcely a file, hammer,
or chisel touches the frame or parts while they are being assembled to work
together. The interchangeable system of construction is, of course, the
only one possible for the accurate production of the millions of sewing
machines now manufactured annually.
_High Arm Construction_.--Sewing machines, as now constructed, exhibit a
rather short and very high arm, a form of framework that has been found to
contribute in no small degree to the light running capabilities of fast
speed machines. While it reduces the length of the various parts concerned
in the transference of the motive power, it adds to their rigidity and
diminishes their weight, maintaining at the same time the capacity of the
machine to accommodate the largest garments beneath the arm.
But the specific improvements in plain sewing machines, to which I have had
the honor of drawing your attention, do not exhaust the list, and, time
permitting, it might be considerably augmented. Nor must it be inferred
that advancement has taken place exclusively in those systems of sewing
machinery now before us.
_Accessories to Sewing Machines_.--The number of special attachments that
have been successfully adapted to plain sewing machines has multiplied so
rapidly of late, that only one or two of the more notable can be spoken of
on this occasion. Perhaps the most generally useful of these is the
trimmer, an arrangement consisting of a vibrating knife, which trims off
the superfluous edge of a seam as the machine stitches it. These are in
extensive use in the factories at Leicester, Nottingham, and elsewhere,
while Northampton and Norwich use the same device for paring the seams in
boot upper manufacture. The chisel-like knife is usually actuated by a cam
rotating with the main shaft, and one or two of the usual forms of this
attachment are to be seen here this evening on both lock and loop stitch
machines.
When machines are moved by the foot, there are many objections to running
the whole machine while winding the shuttle reels. We have, therefore,
several useful devices for releasing the balance wheel of the machine from
the main shaft, while winding. These are to be found both on Wheeler &
Wilson's manufacturing machine and upon Singer's highly finished "Family"
machine, which also carries a most ingenious automatic reel winder, capable
of doing all the work itself, and ceasing to act as soon as the bobbin is
filled.
The setting of the needle in a sewing machine was once quite a task.
Ofttimes it had to be adjusted by chance, in other instances by certain
guiding marks upon the needle bar. It is gratifying to know that all this
has been done away with, and that the needle has only to be inserted into
the bar, and fastened by turning a small screw. These are styled
self-setting needles, and are usually so arranged that they cannot be
adjusted wrongly as to the position of the eye.
In the Willcox & Gibbs machine, and in Singer's single thread machine,
shown here, we have an intermittent tension arrangement, which clamps the
thread at the right moment, and differs from ordinary tension devices,
inasmuch as it may be said to be automatic. The feeder, too, on these
machines is of excellent design, while the arrangements that have been
introduced into the Willcox & Gibbs straw hat sewing machine are
surprisingly effective in spinning up a hat from a loose roll of braid.
Speaking of straw hat machines, mention should be made of Wiseman's hand
stitch apparatus, as improved by Messrs. Willcox & Gibbs, and shown here
this evening. This machine employs two needles, and makes a stitch
resembling hand work at intervals, producing a short stitch at the center
of the hat, and automatically widening the space between the stitches as
the distance from the center increases. The machine itself is of wonderful
ingenuity, and must be examined to be understood.
The stitch making itself is, I believe, quite new, and is also of much
interest. A pair of needles, the width of a stitch apart, rise from beneath
through the material. One of these is an ordinary machine needle, threaded;
the other is a barbed needle. After rising above the surface, the loop of
the threaded needle is seized by a "threader," and thrown into the barb of
the barbed needle. The needles then descend, and the feed occurs, being the
length between stitches. Upon the ascent of the needles again against the
material, the loop is both given off the barb and is entered by the
threaded needle, completing the stitch.
_Of Button Hole Machines_.--The mechanism of button hole machines is so
intricate, that I can only attempt on this occasion to partially elucidate
the construction of one of them, recently introduced, namely, Singer's,
which automatically cuts, guides, and stitches the work.
[Illustration: FIG. 9.]
Fig. 9 exhibits the stitching made by this machine upon the edge of the
button hole. Fig. 10 represents the right and left hand loopers and loop
spreaders, and for the stitch making. They rock from right to left with an
intermittent motion obtained from a cam. The left hand looper carries the
under thread and interweaves it with the upper, forming the stitch,
originally invented, I believe, by Mr. George Fisher, of Nottingham, and
reinvented for the button holing machine by D.W.G. Humphreys, of
Massachusetts, U.S.A., in 1862. The loop spreaders are moved by a roller
carried upon the looper frame. Fig. 11 exhibits the feeding arrangement,
both sides of the feed wheel, the driving lever, and the shape of the path
given to the carrying clamp by the heart cam cut in the upper surface of
the feed wheel. The picture on the screen represents the upper portions of
the machine, exhibiting the conveying clamp, the to and fro dipping motions
of the needle bar, and the parts conveying motion to the arrangements
beneath the bed plate. These are shown in Fig. 12, and represent the feed
and looper cams, the feeding and looper levers, and the stitch forming
mechanism already shown. A most ingenious device in this machine is the
arrangement for automatically lengthening the throw of the feed while
stitching around the eye of the button hole. It is effected by means of a
cam, which imparts more or less leverage to the feed arm by the
intervention of a "shipper" lever, hinged to the feed lever itself. The
space of time at my disposal obliges me to recommend a personal examination
of the machine itself, to fully understand its various motions and its
action in working a button hole.
[Illustration: FIG. 10.]
[Illustration: FIG. 11.]
[Illustration: FIG. 12.]
Mention may be made of Singer's special button hole machine for making the
straight holes used in linen work, and in which a shuttle is employed. Of
Wheeler & Wilson's ingenious button hole machine for the same purpose, I am
enabled to show a diagram, in which it will be observed that the feeding
arrangements are placed above the bed plate, and are no doubt thereby
rendered easily accessible.
_Application of Power to Sewing Machines_.--There was a time when a cry
arose to the effect that the introduction of mechanical sewing would lead
to divers calamities, physical and mental. The ladies were to become
crooked in the spine, and regular operators were to become regular
cripples. It is scarcely necessary to ask, Has this been so? The operators
of to-day are, I think, superior in physical attainments to their sisters
of the needle and thread fifty years ago.
Within the past few years a revolution has taken place in the moving of
sewing machines. Domestic machines will probably always be driven by foot
power, spring, electric, and water motors notwithstanding. But the age of
treadles in the great manufacturing trades is a thing of the past. It was
not necessary for Parliament to step in and protect the workers, as was
frequently suggested by alarmists. The commercial interests of
manufacturers themselves were at stake. Machines driven by power could do
25 per cent. more work than those moved by foot. The operators, relieved of
the treadling, maintained a much better working condition; and altogether
the introduction of power driving, once well tested, became a necessity.
Power sewing machinery was speedily devised and introduced by several of
the first manufacturers, controllers of the speed of the machines followed,
and two or three splendid systems of stitching by steam power were soon
widely known.
By the kindness of three of the best manufacturers of power sewing
machinery, I am enabled to show to you, this evening, the best known
systems, arranged just as they are fitted in many large factories, as also
a sketch of the arrangements of Wheeler & Wilson's system. We have in the
first place a light shafting carrying a band wheel opposite to each
machine. By the use of a powerful electromotor, the shafting is caused to
rotate at the rate of 400 revolutions per minute by electricity. The
current is generated by the Society's dynamo machine, and is conveyed here
by copper cable. I do not know of any instance of sewing machinery in a
factory being driven by an electromotor, but such means of conveying motive
power appears admirably adapted for that purpose, when the stitching room
happens to be far removed from the main shafting or engine. But with regard
to motors for sewing machines, when special power has to be fitted down for
that purpose, my own experience leads me to speak in favor of the admirably
governed "Otto" gas engines made by Crossley Bros. These are especially
steady, a feature of no small moment in moving stitching machinery of
various kinds.
Much attention has been devoted to the invention of controllers of the
motive power supplied to sewing machines. The principle of the friction
disk has found most favor. In many cases two of these plates, fast and
loose, are placed upon the main shaft, and their separation and contact
controlled by the treadle. The great sensitiveness of the friction
attachment employed by the Singer company is due chiefly to the
transference of the friction plates to the axis of the machine itself (Fig.
13). Their contact and separation are controlled by a lever worked by a
very slight movement of the treadle. But the chief point of interest in
this device lies in the combination with the lever of a brake, enabling the
operator, by a simple reversal of the treadle's motion, to instantly
suspend the rotation of the machine. The forked lever, in fact, acts
simultaneously in throwing off the motion and applying the brake. The speed
is always in direct proportion to the pressure exerted upon the treadle,
and a single stitch can be made at will. Fig. 14 shows the friction wheel
separated, the portion a being fast, and e loose.
[Illustration: FIG. 13.]
[Illustration: FIG. 14.]
The Wheeler & Wilson company do not confine themselves to any particular
controller, but prefer the form shown here this evening (Fig. 15), in which
two bands and an intermediate pulley are employed. The first band is left
rather loose, and the machine is set in motion by the tightening of this
band through the depression of the treadle. The speed varies in proportion
to the pressure applied, and the sensitiveness of the arrangement is
increased by a brake device coming into play by the reversal of the treadle
as before.
[Illustration: FIG. 15.]
Messrs. Willcox & Gibbs depend upon a similar device shown in three
varieties to-night.
_Speed of Power Sewing Machines_.--The fastest practicable speed of a
machine worked by the foot appears to be 1,000 stitches per minute. Most
operators can guide the work at a much higher rate, especially in tailoring
or on long seams. The average speed upon such work is 1,200 stitches per
minute; but many lock-stitch machines are run at 1,500 and 1,800 per
minute, and even at much higher rates. There is always a limit to be
imposed upon speed by the guiding powers of hand and eye; it is this limit,
and not the capability of the machine, that confines the rate of driving.
Willcox & Gibbs' single thread machines are run in many instances at 3,500
stitches per minute. We have before us a single thread Singer machine
(appropriately named the "Lightning Sewer") and a Willcox machine, moving
at the enormous rate of 4,500 stitches per minute, and producing good work.
But it is doubtful whether such very great velocities can ever be
advantageously employed. Upon collar work, and in sewing boot uppers, the
rate seldom rises above 1,200 with advantage. If the machines be speeded
too high in any trade, the operator never uses the excess, and it only
proves a drawback. I seen the heaviest and hardest kind of navy boots
stitched at 1,500 to the minute upon Singer's lock-stitch machines. Wheeler
& Wilson's No. 10 D machine has been run by them, I am informed, as high as
2,500 to the minute. Loop-stitch machines, when well made, can be actually
run as high as 6,000, but 4,500 is, I believe, the maximum yet used for
this class of machine, even experimentally. There can be no doubt that
lock-stitch machines can be run as high as 3,000. The actual speeds of the
lock-stitch machines shown here upon the power stand average 1,300; those
of the chain stitch machines vary from 1,200 for the sack sewing machine to
4,500 for the small or single chain stitchers. Any of the latest styles of
either lock stitch or single thread machines can be run far faster than any
known expert operator can possibly guide the work under it.
It is very improbable that such speeds will ever be exceeded. The limit has
no doubt been reached. Very high speed is generally a delusion, and either
results in indifferent work, or actually retards its progress. Some idea of
the speed of the single thread machines now shown may be gathered from the
fact that, running at 4,500, and making eight stitches to the inch, they
accomplish over fourteen yards of sewing every minute.
Of special machines of interest, and which are too unwieldy to be shown
here, I am enabled to exhibit a few photographs.
One of the most novel of these is the "Twin" machine, designed by the
Singer company for the connecting together of the Jacquard cards used in
lace machines. The operation was formerly performed by hand. It is now done
by machine at less cost. The cards are placed upon a feeding drum, and fed
beneath a pair of needles. The laces forming the connection between the
cards are fed above and beneath, in line with the needles, and the whole is
easily stitched together. An extension of the same device is the multiple
machine, in which four needles and shuttles are used, sewing all the four
seams at one operation. This method of linking the cards is considered
better than similar work done by hand.
Of Wheeler & Wilson's new factory, at Bridgeport, and of the Singer
company's great new factory near Glasgow, I am enabled to exhibit
photographic views.
Before drawing my remarks to a close, I would briefly indicate the nature
of the various machines shown upon the power benching. Of the Singer
system, there are four. A drop-feed oscillating shuttle machine for
manufacturing purposes; a wheel-feed oscillating shuttle machine, furnished
with a trimmer, used chiefly in stitching leather and boot uppers; double
chain-stitch machine, used for sack making, now shown for the first time;
and a single thread "Lightning Sewer," fitted with a trimmer for hosiery
work. Of Wheeler & Wilson's system, there is a drop-feed manufacturing
machine with the new detached hook and latest improvements; a No. 10
machine with the usual hook, a wheel feed and trimmer, and a smaller
machine of the same type with drop feed. Of Willcox & Gibbs' system, there
is the ordinary single-thread machine for manufacturing, a single-thread
machine, with a trimmer, as used in the hosiery trades, and a machine
specially used for straw hat making.
We have here a small Singer machine, riding upon the edge of two pieces of
carpet, a carpet machine weighing ten pounds. When the handle is turned, it
stitches and travels over the edges, uniting them faster and more securely
than six hand sewers; and several others, representative of the family type
of sewing machine, besides Wheeler & Wilson's hemstitch machine, the
working of which is of much interest.
I would now invite those of you who seek a better acquaintance with those
curious and novel machines to freely examine and test the various types to
be found upon the power benching and upon stands. One or two operators will
come forward and show some of the capabilities of the machines upon actual
work, in which the making of a straw hat will perhaps show what can be done
in a few minutes by quick speed and expert fingers; but these performances
must not be regarded in the light of competitive tests between the
manufacturers showing them, and are intended merely to show the utility of
motive power driving.
In conclusion, I desire to thank those gentlemen at the head of the leading
firms of sewing machine manufacturers for the trouble they have taken to
arrange for your inspection specimens of their excellent systems, and I
have much satisfaction in expressing my obligations to them for ready
assistance in the preparation of my paper.
* * * * *
Power machines and treadle machines were exhibited by Messrs. Willcox &
Gibbs, Messrs. Wheeler & Wilson, and the Singer Manufacturing Company. The
motive power was provided by an electrical motor, supplied by Mr. Moritz
Immish. The Howe Machine Company exhibited a model of the first machine
made by Elias Howe, and also one of the most recent Howe machines. Mr.
Newton Wilson showed a model of the Saint sewing machines, constructed from
Thomas Saint's patent specification, 1790, and Mr. Carver showed the
Standard sewing machine.
* * * * *