IMPROVEMENTS IN SEWING MACHINES
Year: 1879

page_text: LETTERS PATENT to George. Juengst, of City of New York, and State of New
York, United States of America, for the Invention of "IMPROVEMENTS IN
SEWING MACHINES."
Sealed the 24th February 1880, and dated the 2nd December 1879.
PROVISIONAL SPECIFICATION left by the said George Juengst at the Office
of the Commissioners of Patents on the 2nd December 1879.
GEORGE JUENGST, of City of New York, and State of New York, United States
of America. "IMPROVEMENTS IN SEWING MACHINES."
This Invention mainly comprises the following points :—
"
One part of my Invention relates to the "take up for taking up the needle
thread. The kind of take up which I employ is that in which the principal
element is a vibrating lever, and this part of my Invention consists in a novel
construction and arrangement of the said lever, and novel means of operating the
same, whereby its efficiency is increased.
•
Another part of my Invention relates to the feeding mechanism for feeding the
cloth or material to be sewed.
This part of my Invention consists in novel means of regulating the length of the
feed movement, whereby greater variation in the length of the same is provided
for, also in novel means of regulating the height to which the feeding dog rises
above the sewing surface on which the work is supported, whereby the said dog is
adapted to meet the requirements of the different characters and conditions of the
materials to be sewed.
These improvements in the feeding mechanism are applicable to sewing machines
of various kinds.
Another part of my Invention relates to that class of sewing machines in which
a loose bobbin holder containing the bobbin for supplying the secondary or locking
thread is arranged within an oscillating hook, which is employed to extend the loop
of the needle thread, and it consists in a novel construction of such bobbin holder
to provide for the easy insertion and removal of the bobbin, and for the regulation
of the tension of its thread.
Another part of iny Invention relates to the saine class of machines as that

page_text: herein above mentioned, and it consists in a combination of the feeding-dog with
the bobbin holder, whereby the feeding-dog in its downward motion is made to
press on the bobbin holder, and so made to press the latter away from the position
to which it has been brought in the tightening of the last previously formed stitch,
so that when the dog rises again the bobbin holder may be left free for the passage
of the loop of the needle thread over or around the bobbin.
Another part of my Invention relates to the reaction spring, by which the feeding-
dog is returned after its feeding movement, and it consists in means of regulating
the downward pressure of the said spring on the dog, so that it may be sufficient to
cause such an operation as is herein-above mentioned of the feeding-dog on the
bobbin holder, or sufficient for any other desired purpose.
Another part of my Invention relates to the tension device for producing the
necessary tension on the needle thread.
The tension device which I employ is of that well known kind consisting of two
discs, between which the thread is clamped by the pressure of a spring to produce
friction upon it, and this part of my Invention consists in means whereby the
pressure of the spring may be removed instantaneously from the discs to permit
the taking out and insertion of the thread, or facilitate threading up, and be
re-applied without variation or need of re-adjustment.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Juengst in the Great Seal Patent Office on the 1st June
1880.
GEORGE JUENGST, of the City of New York, and State of New York, United
States of America. "IMPROVEMENTS IN SEWING MACHINES."
One part of my Invention relates to the "take-up" for taking up the needle
thread. The kind of take up which I employ is that in which the principal
element is a vibrating lever, and this part of my Invention consists in a novel
construction and arrangement of the said lever, and novel means of operating the
same, whereby its efficiency is increased.
Another part of my Invention relates to the feeding mechanism for feeding the
cloth or material to be sewed. This part of my Invention consists in novel means
of regulating the length of the feed movement, whereby greater variation in the
length of the same is provided for; also in novel means of regulating the height
to which the feeding dog rises above the sewing surface on which the work is
supported, whereby the said dog is adapted to meet the requirements of the different
characters and conditions of the materials to be sewed. These improvements in the
feeding mechanism are applicable to sewing machines of various kinds.
Another part of my Invention relates to that class of sewing machines in which
a loose bobbin-holder containing the bobbin for supplying the secondary or locking
thread is arranged within an oscillating hook, which is employed to extend the loop

page_text: of the needle thread, and it consist in a novel construction of such bobbin holder to
provide for the easy insertion and removal of the bobbin, and for the regulation of
the tension of its thread.
Another part of my Invention relates to the same class of machines as that
hereinabove mentioned, and it consists in a combination of the feeding dog with
the bobbin holder, whereby the feeding dog in its downward motion is made to
press on the bobbin-holder, and so made to press the latter away from the position
to which it has been brought in the tightening of the last previously formed stitch,
so that when the dog rises again the bobbin holder may be left free for the passage
of the loop of the needle thread over or around the bobbin.
Another part of my Invention relates to the reaction spring, by which the feeding-
dog is returned after its feeding movement, and it consists in means of regulating
the downward pressure of the said spring on the dog, so that it may be sufficient to
cause such an operation as is herein above mentioned of the feeding dog on the
bobbin holder, or sufficient for any other desired purpose.
Another part of my Invention relates to the tension device for producing the
necessary tension on the needle thread. The tension device which I employ is of
that well known kind consisting of two discs, between which the thread is
clamped by the pressure of a spring to produce friction upon it, and this part of my
Invention consists in means whereby the pressure of the spring may be removed
instantaneously from the discs to permit the taking out and insertion of the
thread, or falicitate threading up, and be reapplied without variation or need of
re-adjustment.
DESCRIPTION OF THE DRAWINGS.
In the accompanying Drawings, Figure 1 is a side elevation partly in section of a
two thread sewing machine, having my improvement applied; Figure 2 is an
inverted plan of the machine; Figure 2* is a vertical section of the head of the
machine of the tension device; Figure 3 is a transverse vertical section of the
machine on the line x, x, shewn in Figure 1 ; Figure 3*, a face view of the take-
up and its operating mechanism; Figure 4 is a transverse vertical section of the
machine on the line y, y, Figure 1; Figure 5 is a vertical section parallel with
Figure 1 of the head of the machine, in illustration of the devices for operating the
needle-bar and take-up; Figure 6 is a vertical section parallel with Figure 1,
showing part of the mechanism for operating the feed; Figure 7 is a plan, and
Figure 8 a side view partly in section of the bobbin holder for containing the
secondary thread; Figure 9 is an elevation partly in section, illustrative of the
hereinbefore mentioned operation of the feeding dog on the bobbin holder;
Figure 10 exhibits a vertical section on a larger scale than the other Figures of the
feeding dog, and side view of its reaction spring, illustrating the adjustment of
said spring. Similar letters of reference indicate corresponding parts in the several
Figures: A is the cloth bed, and B the stationary arm, in which is supported the
main shaft C, from which motion is derived to operate the several working parts
of the machine. D is the needle bar, arranged to work up and down within the
head or face-plate K of the machine. This needle bar may be of any convenient
cross section; it has fastened to it a ground or slotted cross piece C, which serves to
receive within it a roller d on the wrist pin e of the disk or crank f, fast on the
forward end of the main shaft C, whereby the requisite up and down motion is
communicated to the needle bar. The same wrist-pin carries a second roller g,
acting under the lower arm or lever i of the double armed or pronged take up
lever E, i, against the pressure of a spring h, which is coiled around the fulcrum-pin k
of said lever, and keeps said lower arm down on the roller g, and serves to
return it after being lifted by said roller. The pivot or fulcrum k is near and above
the circle described by the roller g, and the under surface of the arm i, against
which said roller acts, is curved to correspond with the circle described by said
roller at the highest portion of its travel, as shewn in Figure 3*, thus causing the
take-up lever to come to a positive rest against the adjustable cushion S', regulated

page_text: by a screw S², screwing into the head K of the machine, and a presser S*, which
is fitted as shewn in the detached perspective view, Figure 3**, with a sleeve S³ to
said screw.
The lever rests against this cushion until the needle has descended to
a point where its eye is nearest the thickest material to be sewed, at which time
the take up begins to descend, and pay out the necessary slack thread to let the
needle pass through the goods, and to form the loop. This take up is applicable to
various kinds of sewing machines, but the following description of its operation in
connection with the oscillating hook and contained bobbin holder for carrying the
secondary thread in the machine represented will apply to its operation in
combination with any other device for carrying a secondary thread or extending
the loop of the needle thread.
In the operation of the machine by the construction of the curvature of the
lowest arm i of the lever E, i, and the arrangement of the pivots or fulcrum k of
the said lever relatively to the centre of the main shaft C, as hereinabove
described, the motion of said take-up can be so regulated that the time of rest of
the same is continued for about one quarter of the revolution of shaft C.
During the next two-quarters of the saine revolution the take up is caused to
descend by the action of its spring h, paying out the necessary thread, and during
the remaining quarter of said revolution, which is after the needle leaves the throat
hole of the cloth-plate, and after the oscillating hook G has carried the needle thread
loop around the bobbin holder H within said hook, said take up E, i, is moved
upwards again till same arrives at its highest point in the completion of the
revolution of shaft C.
The feeding dog M is operated substantially as follows:-On the main shaft C is
a cam d' (see Figs. 4 and 6) working in a yoke at the upper end of a rod e¹, which
is free to bear laterally against the adjustable fulcrum piece es, whereby the said
rod e¹ is converted into a lever, and its lower end is caused to describe a line forming
a parallelogram, the vertical sides of which are of the saine length as the stroke of
the cam d, while the horizontal sides of said paralellograin are longer or shorter
than said stroke, according to the position of the adjustable fulcrum piece e³. The
vertical motions of the lower end of said rod e¹ have the same direction as the top
part of said rod, while the lateral motions at the lower end are reverse to those of
the top part.
Said lower end of rod e¹ is attached to a lever N, which is supported on a rounded
fulcrum bearing o³ forming part of the horizontally adjustable slide O, whereby the
up and down motions at the rod end of said lever N are reversed in direction and
changed in length at the opposite end, where it engages the feeding dog.
According to the relative position of the slide O and fulcrum bearing o³, which
rests on the stationary sole piece O' and is held in position by a screw and clamping
nut 0%, situated for convenience on the upper side and near the rear end of the
surface of the bed of the machine, the requisite up and down motion is imparted to
the feeding dog, causing the same to project more or less through the sewing surface,
as the nature of the material inay require.
The said up motion is made positive by the cam, while the down motion is due
to the reaction of a spring f*; said spring f* is made adjustable by being fastened to
a rocking shank f¹ (see Figures 2 and 10), which by means of the screw may be
held in a more or less inclined position, whereby the vertical pressure of said spring
may be varied, for reasons to be hereinafter mentioned. The lateral pressure of
said spring pushes the feeding dog M back, and in doing so keeps the lever N in
contact with the scale bean bearing or fulcrum g' (see Figure 2) attached to or
carried by a slide ¹, adjustable along the bed A. to vary the length of the feeding.
The oscillating hook G, which is of cup-shape and has the bobbin holder H loosely
arranged with it, is driven by or from an eccentric P on the main shaft C. This
eccentric is connected by a rod k' with the crank l, and serves to rock a shaft m
which has on its forward end a toothed sector m², which gearing with a pinion ni
fast on the upright arbor o' communicates to the hook G fast on the upper end of
said arbor an oscillating motion equal to a little more than a complete revolution

page_text: each way around the bobbin holder H. The motion of the hook G is so regulated
that the point of the same, when going forward, is opposite the needle / after the
latter has moved sufficiently upwards to form the loop in the needle thread. The
arbor O¹ turns in a bearing or bracket on the underside of the cloth plate A; said
bearing or bracket 21 may be made slightly adjustable in a direction to and from
the needle, thus making it possible to bring the point of the hook G in any desired
degree of proximity to the needle Z.
The point or nose end u' of the hook G is made of such width at its base as to
reach slightly below the bobbin-holder H, and when entering the loop of the needle-
thread it gradually expands the same, and as it continues its forward motion carries
the inside portion of loop obliquely downward around the bobbin holder H until
said portion of the loop reaches the lower edge of said holder, when it slips under
the latter, while that portion of the loop which is outside of the hook is carried over
said holder until it has crossed the vertical centre of said holder. At this period
the take-up E begins to ascend and pulls the loop from the point of the hook G and
fully around and from under the bobbin-holder H, thus interlocking the secondary
thread a drawn from the bobbin 62 in the holder E with the needle-thread a', and
pulling both threads through the hole m in throat plate A', and into the material
to be sewed. The bobbin-holder H (see Figures 7, 8, and 9) is of circular forin, and
made in two cup-shaped parts d³ and e² of unequal depths; the deeper part de has
a series of openings in its side, through one or more of which the interlacing
thread a from bobbin 63 is passed or threaded (as shown in Figures 7 and 8) to
regulate the tension of said thread to any desired degree.
The primary tension may be produced, in addition to the friction caused by the
weight of the bobbin on the bottom of the holder, by lining said holder with any
suitable material, or by providing a special clamping spring for the purpose. The
openings in the side of the deeper part dare cut through, so as to make the
remaining lips or tongues constitute a series of springs for the purpose of holding
the lid or part e secure by spring friction when closed, yet permit the removal of
the same readily when desirable.
In this Invention the feeding dog Ml acted by cam d¹, rod el, lever n, and spring ƒ*
performs another and important function besides moving the material to be sewed
and spacing the stitches, inasmuch as when the stitch is tightened the loose bobbin-
holder H is drawn up against the feeding dog M; or if said dog should raise so high
that its underside would be above that of the plate A', then the bobbin holder is
against said plate A' (as shown in Figure 9), and the pressure so produced, and which
is proportionate to the tension of the bobbin-thread, would materially interfere with
the forming of a good and even seam. To overcome this difficulty, which is always
found where a stationary bobbin-holder (or shuttle) is used, the forward end of the
feeding dog M is made to overlap one side of the bobbin-holder H (as shown in
Figures 3 and 9), and being forced down (as shown in dotted outline in Figure 9)
by the action of spring f, and to a certain extent by the yielding pressure of the
presser-foot it forces the raised side of the bobbin-holder down to its norinal or nearly
normal position; now the feeding dog slides back keeping said bobbin-holder down,
but the following rise or lift motion of said dog leaves the bobbin-holder is a free
and slightly loose condition, whereby an unobstructed passage for the needle-thread
around the bobbin-holder is secured. This action on the bobbin-holder may be
produced by a separate mechanism, which may be operated either directly or
indirectly from the main shaft, but it has to produce substantially the same effect,
viz., liberating the bobbin-holder from the resting place against which it was drawn,
and has been held by the binding of the stitch and the action of feeding of the
material. The spring f* is adjustable in its downward pressure by means of the
screw at the rear part of the socket f¹, which latter bears against the lug f³ (see
Figures 2 and 10), and rocks on the underside of the bed at the point f* (see
Figure 10), whereby it is possible to have the pressure always in excess of the
resistance caused by the different degrees of tension on the bobbin thread.
The improvement in the tension device is illustrated in Figure 2. t, t, are the

page_text: two disks between which the thread passes, and is clamped to produce friction, and
consequently tension; these disks are fitted loosely to a spindle u which is free to
slide or move longitudinally through the head K, and which is screw threaded on
its front part, and provided with a head at its rear end. A nut v is fitted to the
screw thread, and a spring w secured to the back of the face-plate of the head
presses against this nut in such manner as to press the head of the screw against
the back disk t, press the disks together, and press the front one t against the back
of the head K. The nut v passes freely through the face-plate of the head K, and
screwing up against the spring w serves to adjust the tension produced by the disks,
the spindle being prevented from turning by being furnished with a fin u' which
enters a notch in the head. When it is desired to take the pressure off the thread
between the disks for threading up or otherwise, all that is necessary is to push
with the thumb or finger against the face of the nut with force enough to over-
come the pressure of the spring, and.so push back the spindle u, as shown in dotted
outline in Figure 2*, and leave the disks loose and thread free. On relieving the
nut of the pressure the spring presses forward the nut and spindle, and restores
the pressure to the disks without variation or need of re-adjustinent as is necessary
when the only way to take off the pressure is to turn back the adjusting nut.
Having thus particularly described and ascertained the nature of my Invention,
and the manner in which same is carried into effect, I would have it understood
that I disclaim all other sewing machines now in use, what I claim as my Invention
being,-
1st. The combination of the take-up lever E, i, the needle driving crank pin e
and a spring for keeping the said lever against the said crank pin and producing its
downward motion, substantially as herein specified.
2nd. The adjustable cushion s', and its presser 84, sleeve &, and screw s², in com-
bination with the take-up lever, substantially as herein described.
3rd. The combination with the feeding dog of the lever N, rod or lever e,
cam d, and the two adjustable fulcrums g and e³, whereby a great degree of
variation in the length of the inovement of the dog is provided for, substantially
as herein shown and described.
4th. The combination with the feed operating lever N of an adjustable fulcrum Os
for regulating the height to which the feeding dog rises, substantially as herein
described.
5th. The loose bobbin holder, constructed substantially as herein described, in
combination with an oscillating hook for forming the stitch.
6th. The feeding dog in combination with the bobbin-holder and the oscillating
hook, substantially as herein described, whereby the said dog is made to depress
the bobbin-holder after the tightening of the stitch, substantially as herein set
forth.
7th. The combination with the reacting spring of the feeding dog of means
of adjusting the downward pressure of the said spring, substantially as herein
described.
8th. The combination with the tension disks t, t, and their sliding or longi-
tudinally moving spindle of a nut and a spring applied to operate and permit the
movement of the spindle, substantially as herein described.
In witness whereof, I, the said George Juengst, have hereunto set iny hand
and seal, this Sixth day of May, in the year of our Lord One thousand
eight hundred and eighty.