IMPROVEMENTS IN SEWING MACHINES CHIEFLY DESIGNED FOR LEATHER-WORK
Year: 1880

page_text: LETTERS PATENT to Harry Mills, of Birmingham, in the County of Warwick,
for an Invention of "IMPROVEMENTS IN SEWING MACHINES CHIEFLY DESIGNED
FOR LEATHER-WORK." A communication from abroad by Daniel Mills, of
Philadelphia, Pennsylvania, United States of America.
PROVISIONAL SPECIFICATION left by the said Harry Mills at the Office of
the Commissioners of Patents on the 22nd September 1880.
HARRY MILLS, of Birmingham, in the County of Warwick.
"IMPROVEMENTS IN
SEWING MACHINES CHIEFLY DESIGNED FOR LEATHER-WORK." [A communication
from abroad by Daniel Mills, of Philadelphia, Pennsylvania, United States of
America.]
My Invention relates to improvements in wax thread sewing machines chiefly
designed for sewing leather and similar materials.
In an ordinary sewing machine which makes a lock stitch with two threads and
is intended to sew cloth, the needle has an eye a certain distance from the point,
and is grooved lengthwise in such a manner that there is room for the thread, so
that it can be drawn up as required while the needle is in the fabric being sewn.
When machines are intended to sew leather and non elastic materials, especially
with a waxed thread, it has been found impracticable to use eyed needles by
reason of the needle and thread having to be in the material at the same time,
and as holes made in non-elastic materials do not close up after the withdrawal of
the needle, the said holes are too large for any thread that can be used with such
needles. Another difficulty has been the length of thread pulled through the
material at each stitch, hence the general adoption of chain or loop stitch machines
for such work.
In the latter class of machines a barbed or crochet needle is used, and as the
stitch is pulled up when the needle is out of the work, it is evident that a much
smaller needle can be used.
In some chain or loop stitch machines the needle is the sole piercing instrument,
and it has also to pull up the stitch. In others there is an awl or piercing
instrument, but still as the needle has to pull up the stitch it must be large in
proportion to the thread, so that there will be strength enough in the barb to
resist the strain to which it is subjected.
In machines hitherto devised for making a lock stitch with waxed thread, some

page_text: have an eyed needle and a reciprocating hook to spread the thread for the passage
of the shuttle, the needle in such machines being on one side of the material and
the shuttle on the other. Attempts have also been made to use a barbed or
crotchet needle in combination with a book having a reciprocating movement
around its axis, and in some machines a loop opener has been employed to open
the loop for the passage of the shuttle.
All lock stitch machines as hitherto constructed for sewing with waxed thread,
however, are objectionable on account of the excessive amount of thread drawn
through the work in order to form the loop, and both lock stitch and chain stitch
machines as heretoforo constructed necessitate the use of large needles, the
perforations formed by which are not filled by the thread.
The main object of iny present Invention is to construct a lock stitch machine in
such a manner that very little more thread will be drawn through the work than
is the case in a chain or loop-stitch machine; further objects being to puncture
and feed the work and pull up the stitch by means other than the needle, and to
obviate excessive pressure on the presser foot.
In carrying the said Invention into practice I provide the main frame of the
machine with a projecting arm, and at the rear with bearings for a transverse shaft
which carries a driving wheel, and is furnished with two cam discs, when several
operating parts of the machine derive their movements, as hereinafter described.
To bearings in the projecting arm of the frame I adapt a tubular shaft, upon the
front end of which is formed a segmental shield, having on its outer edge a flange
so shaped at one end as to form a hook. The rear end of the said tubular shaft is
provided with-an-elliptical gear wheel which engages with a similar wheel turning
-on-a-stud_on_the_frame and receiving motion-from-the-transverse shaft through the
medium of the bevel and spur wheels.
By employing the elliptical gear wheels the speed at which the tubular shaft.is
driven will be differential, for a purpose hereinafter explained.
In addition to the rotary movement of the tubular shaft a longitudinal movement
is imparted to it by the engagement of a friction roller on a stud with a cam slot
formed in a sleeve secured to the said shaft. This stud is carried by a slide
adapted to a slot in the frame, whereby longitudinal adjustment of the said stud is
permitted to effect the proper longitudinal adjustment of the aforesaid tubular
shaft.
The shuttle I employ is cylindrical and works in a shuttle race formed partly in
the tubular shaft and partly in a bracket secured to the front end of the arm of
the frame. The reciprocation of the said shuttle is effected by means of two
drivers, the first driver working in the tubular shaft and acting on one end of the
shuttle, and the second driver working in that portion of the shuttle race which is
within the limits of the aforesaid bracket, and acting on the opposite end of the
shuttle.
The rod of the first driver is connected to a lever hung to the frame of the
machine and having a stud upon which is a roller adapted to a cam groove on one
of the aforesaid cam discs.
The second driver is also connected to a lever through the medium of an
external bar or arm adapted to a suitable guide in the arm of the frame, a stem on
the said driver projecting through a longitudinal slot in the aforesaid bracket, and
through a slot in the end of the external bar; the said stem has a collar, and the
end of the arm is clamped between the said collar and a thumb nut adapted to the
threaded portion of the stem. It is important that the said driver should always
be secured to the external bar in a certain longitudinal position in order that the
proper space may intervene between the acting faces of the two drivers and the
ends of the shuttle, and in order to insure this proper relation of the parts before
the second driver can be secured to the external arm I enlarge the inner end of
the slot in the end of the saune, and so adapt the nut to the said slot that it can
only be turned when it occupies a position within the enlargement of the slot.
The shuttle is provided with a cap or cover connected to the body of the shuttle

page_text: by means of a bayonet joint fastening, comprising pins on the cap and slots in the
body of the shuttle, so that the said cap can be readily removed and replaced.
The thread passes from the interior of the shuttle through an opening in a central
projection on the cap, thence between the inner face of the said cap and a tension
spring, and finally through openings in the cap and shuttle body. The tension
spring is preferably made in the form of a segment, and is secured at one end to
the inner face of the cap by means of a screw, the adjustinent of the said spring
being effected by means of a screw which projects through the cap of the shuttle,
so that on removing the second driver from the shuttle race the screw may
be manipulated and the tension varied without removing the shuttle itself
from the shuttle race, the regulation of the tension of the shuttle thread being thus
accomplished without interfering with the formation of a perfect and continuous
series of stitches.
I use an ordinary barbed needle, which is secured to the upper end of the needle.
bar preferably by means of a paper chuck. This needle bar is adapted to bearings in
the aforesaid bracket, so as to be free to reciprocate vertically therein, the said bar
as it is moved vertically being also partially rotated through the medium of a
scroll slot in the bar, with which engages a roller carried by a stud or arm secured
to the bracket of the frame.
A threaded sleeve is screwed loosely on to a threaded portion of the needle bar,
the said sleeve having a projection adapted to a vertical groove in the bracket of
the frame, and being provided with a stud carrying a flattened roller, which enters
a slot in the end of an arm hung to the arin of the frame, and having a slot for the
reception of a pin, which is also adapted to a slot in a lever pivotted to the frame
and carrying an anti-friction roller, adapted to a cam groove in one of the cam discs
of the driving shaft. By shifting the pin in the slots of the arm and lever, the
throw of the needle bar may be increased or diminished as desired, by reason of the
fact that the arm and lever are centred at different points, the variation being
always at the bottom of the stroke, for when the needle bar is at the top of its
stroke, the slots in the arm hung to the arm of the frame and the lever are directly
in line with each other, so that the pin can be shifted in the said slots without
effecting any movement of the needle bar. When the needle bar is at the bottom
of its stroke, however, the slots are not in line with each other, and a variation in
the position of the last named pin causes an elevation or depression of the needle bar.
The awl I employ is secured by means of a tapered chuck or otherwise to the
lower end of a stem, which is adapted to a bearing in a plate, and is connected by
means of a link to a bar which reciprocates in bearings in the front end of the
frame, the operation of said bar being effected by a cam groove in one of the
aforesaid cam discs of the driving shaft through the medium of a lever pivotted to
the frame by a transverse pin and having a stud adapted to the cam groove in the
disc.
The plate or slide which supports the stem carrying the awl is adapted to lateral
guides in a plate secured to the frame, and having a bearing for a vertical bar, a
bracket on which carries a roller adapted to a slot in a plate hung to the above
named plate and having a segmental slot for the reception of the stein of a thumb
screw, whereby the said plate may be secured in any position to which it has been
adjusted.
The plate which has the segmental slot, being adjusted to such a position that
the said slot will be inclined in respect to a vertical line, the reciprocation of the
bar will owing to the engagement of its roller with the said slot, cause a lateral
vibration of the plate or slide, the extent of the vibration being governed by the
angle of the slot; this angle can be readily determined by means of a pointer on
the slotted plate in connection with a segmental graduated scale on the plate or
slide. As the feeding of tho work is accomplished by the lateral movement of the
puncturing awl, the extent of this movement determines the length of the stitch
hence this provision for readily and accurately regulating the extent of the
movement.

page_text: The upper end of the reciprocating vertical bar has a stud which is adapted to
a slot in one arm of a lever hung to the transverse pin of the frame, and having on
its other arm a stud adapted to a cam slot in one of the cam discs of the driving
shaft, whereby on the rotation of the said disc the desired vertical reciprocation of
the said bar is effected.
The looper I employ is carried by the short arm of a lever hung to the lower
end of an arm which is pivotted at its upper end to the frame, and has an inclined
slot for the reception of a roller on a stud on one arm of a lever hung to the
transverse pin above referred to, the opposite arm of the said lever having a stud
adapted to a cam slot in one of the said cam discs. The long arm of the lever
carrying the looper has at its upper end an inclined slot to which is adapted a stud
on the reciprocating vertical bar, so that as the lever hung to the transverse pin is
vibrated and the vertical bar reciprocated a combined lateral and longitudinal
movement somewhat similar to that of an ordinary four motion feed is imparted to
the looper; the lateral movement of the said looper is duc to the swinging of the
pivotted arm by the engagement of the stud with its inclined slot, and the longitu-
dinal movement is caused by the vibration of the looper carrying lever, due to
the engagement of the stud of the vertical bar with the inclined slot of the said
lever.
It is desirable in a machine of the class to which my Invention relates to hold
the work firmly so as to resist the action of the awl and needle while the stitch is
being made, and yet permit the ready feeding of the material.
When the presser
bar is acted upon by a spring heavy enough to firmly retain the work during the
sewing operation the feeding would be retarded in the absence of mechanism for
automatically-raising the foot, and when a light spring only is employed the work.
---is not properly retained on the bed at all times. These objections I overcome by
using a light spring on the presser_bar, and by employing in-connection with the
said bar means whereby it may be automatically locked and rigidly held in position
between the feeding operations.
For this purpose I secure the presser foot to the lower end of a hollow bar
adapted at the lower end to a bearing on the frame, and at the upper end to
bearings on lugs, that portion of the bar between the said lugs being adapted to a
sleeve, a tubular stem on which fits within a lug on the frame, and has an internal
thread adapted to the threaded front end of a rod, the rear end of which passes
through and has its bearing in a lug on the framio.
The projecting rear end of the said rod has a collar and an arm, the latter being
furnished with an anti-friction roller at the end, and being acted upon by a spring
and by a cam on one of the cam discs of the driving shaft. Between the feeding
operations the said arm is under the control of the spring, and as the said rod is
incapable of moving longitudinally owing to the contact of its collar with the
bearing the threaded end of the rod will act upon the threaded stem of the sleeve
and cause the latter to draw upon the presser bar and bind it tightly in its bearings
in the lugs, thereby preventing the elevation of the presser foot by any upward
pressure on the work. The action of the cam on the arm tends to turn the rod so
as to release the strain on the presser bar when the work has to be fed forward.
The bar carrying the presser foot is hollow, as above explained, and within the
bar is a spring which bears at the lower end against an adjusting screw and at the
upper end against a block carried by a pin, the latter extending transversely
through the upper lug' and through the said bar, slots being formed in the latter
to permit the elevation of the said bar, which operation is effected by means of a
lever hung to the frame and acting on an antifriction roller carried by a stud on
the bar.
The thread is drawn from a spool supported in bearings on the top of the frame,
and acted upon by a suitable tension device, the thread passing from the spool
over a roller in the frame, thence round a roller on a take up lever, thence round a
roller on the frame, and finally round two other rollers to the looper. The second
of these two rollers is carried by a bracket on a tube which extends through the frame,

page_text: and the first roller is carried by a rod adapted to slide on a bearing on the said
tube, and acted upon by a spring, so that the last named roller is free to yield,
as necessitated by the irregular action of the looper.
To maintain the two rollers and the parts of the machine adjacent thereto which
act upon the thread at the proper degree of heat, a jet of gas from a pipe is pro-
jected into the tube which extends through the frame, the heat being thereby
deflected downwards so as to come in contact with the looper awl, the thread
guiding wheels, and the parts adjacent thereto. The shuttle race, shuttle drivers,
and shuttle are also maintained at the propor degree of heat by a burner, the flame
from which is projected against the underside of the aforesaid bracket of the frame
and is confined thereto by side ribs.
The work rests upon a work plate which has the usual slot for the passage of
the needle and awl.
The take up lever is hung to the frame of the machine and is acted upon by a
cam on the transverse shaft in such a manner that a certain quantity of slack.
thread will be formed, which as the needle descends after receiving a loop from the
looper will be gradually delivered by the rise of the froller of the said lover, so
that the thread will not be drawn through the hook of the needle as the latter
descends, but will be delivered at the same speed as that at which the needle
moves. By this means I prevent that excessive friction and wearing of the thread
which results when the strain on the thread is not released when the needle is
descending.
The object of driving the aforesaid tubular shaft carrying the segmental shield
by means of the differential gearing above described, is to impart a differential
velocity to the said shaft, so that while the hook operates very quickly in removing
the loop from the needle, and distending the said loop for the passage of the
shuttle, the remaining portion of the rotation of the hook is at such a lower rate of
speed that ample time is afforded for the proper operation of the shuttle needle,
awl, and looper.
The said tubular shaft is arranged at right angles to the direction of the feed, so
that the mechanism whereby the shaft is driven is entirely out of the way of the
work which is being sewod; this arrangement also ensures the pulling up of the
stitch by the action of the segmental shield in a direction parallel with the line of
the seam, thereby ensuring the production of neater work than could be produced
if the loop were drawn at right angles to the scam. The hook rotates in a direction
the reverse of that in which the work is fed, so that the loop of needle thread will
always be in proper position for the entrance of the hook, the termination of the
feed motion being always at the same point.
The segmental shield in connection with the hook provides for the formation of
the loop for the passage of the shuttle without drawing through the work the
excessive amount of thread demanded in making the loop in ordinary lock stitch
wax thread sewing machines, the amount of thread drawn through the work in my
improved machine being but little if any greater than in an ordinary chain stitch
machine. The shield also serves the purpose of drawing up or tightening the
stitch previously formed, thereby removing the strain from the needle and enabling
the use of a much lighter needle than can be used when the stitch has to be drawn
up by the needle itself, the only duty of the needle in my improved machine being.
to catch the loop from the looper and draw it through the work.
Although I prefer to use an awl for puncturing and feeding the work, the main
features of my Invention may be embodied in machines in which the needle itself
punctures the work, and either feeds the same or works in conjunction with
independent feeding mechanism, and the barbed needle and rotating loop catching
hook may be used in connection with a device other than the shield for opening
the loop and drawing up the stitch.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Harry Mills in the Great Seal Patent Office on the 22nd March
1881.
HARRY MILLS, of Birmingham, in the County of Warwick. "IMPROVEMENTS IN
SEWING-MACHINES CHIEFLY DESIGNED FOR LEATHER WORK." A communication
from abroad by Daniel Mills, of Philadelphia, Pennsylvania, United States of
America.
This Invention relates to improvements in sewing machines, chiefly designed for
sewing leather and similar materials.
In an ordinary double thread sewing machine which makes a lock stitch, and is
intended to sew cloth, the needle has an eye at a suitable distance from the point,
and is grooved lengthwise in such a manner that there is room for the thread to be
drawn up as required while the needle is in the fabric being sewn.
When machines are intended to sew leather and other similarly non-elastic
materials, especially with a waxed thread, it has been found impracticable to use
eyed needles, for the reason that the needle and thread have to be in the material
at the same time, and as holes made by a needle in non-elastic materials do not
-close_up after the withdrawal of the needle, the said holes are too large for any
thread that can be used with such-needles. Another difficulty has arisen from the
length of thread-pulled through the material at-each-stitch, hence the general
adoption of chain or loop stitch machines for such-work,
In the latter class of machines a barbed or crochet needle is used, and-as-the_
stitch is pulled up when the needle is out of the work, it is evident that a much
smaller needle can be used.
In some chain or loop stitch machines the needle is the sole piercing instrument,
and it has also to pull up the stitch. In others there is an awl or piercing instru-
ment, but as the needle has to pull up the stitch, it must be large in proportion to
the thread, so that there may be strength enough in the barb to resist the strain to
which it is subjected.
In machines hitherto devised for making a lock-stitch with waxed thread, some
have an eyed needle and a reciprocating hook to spread or open the thread for the
passage of the shuttle, the needle in such machines being on one side and the shuttle
on the other side of the material being sewn. Attempts have also been made to
use a barbed or crochet needle in combination with a hook having a reciprocating
movement around its axis, and in some machines a loop opener has been employed
to open the loop for the passage of the shuttle.
All lock-stitch machines as hitherto constructed for sewing with waxed thread,
however, are objectionable by reason of the excessive amount of thread drawn
through the work in order to form the loop, and both lock-stitch and chain stitch
machines as heretofore constructed necessitate the use of large needles, the
perforations formed by which are not filled by the thread.
The main object of this Invention is to construct a lock-stitch machine in such a
manner that very little more thread will be drawn through the work than is the
case in a chain or loop stitch machine, its further objects being to puncture and
feed the work and pull up the stitch by means other than the needle, and to
obviate excessive pressure on the presser foot.
In the accompanying Drawings,
Figure 1 is an elevation of one side of a machine constructed according to this
Invention, and
Figure 2 is an elevation of the opposite side of the said machine.

page_text: Figure 4 is a longitudinal vertical section partly on the line 1-2, and partly on
the line 3-4, Figure 3.
Figure 5 is a section of part of the stitching mechanism and presser foot detached
and drawn to an enlarged scale.
Figure 6 is a longitudinal vertical section of part of the machine also drawn
to an enlarged scale, and showing the shuttle, the shuttle race, and the shuttle
drivers.
Figures 7 and 8 are sectional views of portions of Figure 2, shewing the mechanism
for retaining and releasing the presser foot.
Figure 9 is a transverse section of part of Figure 3 on the line 5-6.
Figures 10 and 11 are views of parts of Figure 9.
Figure 12 is a sectional view of the presser bar and its attachments, and
Figure 13 is a side view of the needle and needle bar, shewn in section in
Figure 5.
Figure 14 is a horizontal section on the line 7-8, Figure 5.
Figure 15 is a front view of the rotary hook which forms the loop for the passage
of the shuttle, and
Figure 16 is a longitudinal section of the said hook.
Figure 17 is a front elevation of part of the machine looking in the direction
of the arrow, Figure 2.
Figure 18 is a horizontal section on the line 9-10, Figure 17.
•
Figures 19, 20, 21, 22, and 23 are views of parts of Figures 17 and 18.
Figure 24 is a transverse section of the shuttle-race on the line 11-12,
Figure 2.
Figure 25 is a horizontal section on the line 13-14, Figure 24, showing one of
the shuttle drivers and its operating rod.
Figure 26 is a side view of one end of the said operating rod, and
Figures 27, 28, and 29 are views of parts of the shuttle.
A represents the main frame of the machine, which has a projecting arm D, and
is provided at the rear with bearings for a transverse shaft B; this shaft carries a
driving wheel E, and is furnished with two cam discs C, C', from which several
operating parts of the machine derive their movements, as hereinafter described.
To bearings as, a³ (Figure 4), in the arm D of the frame A, I adapt a tubular
shaft a, upon the front end of which is formed a segmental shield a³ (Figures 5
and 15), having on its outer edge a flange so shaped at one end as to form a
hook a¹. The rear end of this shaft is provided with an elliptical gear wheel a
(Figure 4), which engages with a similar wheel a³, turning upon a stud on the
frame A, and receiving notion from the shaft B, through the medium of the bevel
wheels a and spur wheels a?.
By the employment of the elliptical gear wheels a, a, the speed of the shaft a
will be differential as and for a purpose hereinafter explained.
In addition to the rotary movement of the tubular shaft a, a longitudinal
movement is imparted thereto by the engagement of a friction roller on a stud a®
with the cam slot formed in a sleeve a secured to the said shaft a (see Figures 4,
9, 10, and 11). This stud a is carried by a slide adapted to a slot in the frame A,
whereby longitudinal adjustment of the said stud is permitted to effect the proper
longitudinal adjustment of the shaft a.
The shuttle b which I employ is cylindrical and works in a shuttle race b'
formed partly in the tubular shaft a, and partly in a bracket D' secured to the
front end of the arm D of the frame. The reciprocation of this shuttle is effected
by means of two drivers b³, b³; the driver 6' works in the tubular shaft a and
acts on one end of the shuttle, and the driver b³ works in that portion of the
shuttle race which is within the limits of the bracket D' and acts on the opposite
and of the said shuttle.
The rod of the driver b' is connected to a lever 6º (Figure 2) hong on the frame
of the machine at 61° and having a stud 611, upon which is a roller adapted to a
cam groove on the disc C¹.

page_text: The driver is also connected to the lever 6 through the medium of an
external arm or bar b' adapted to a suitable guide in the arm D of the frame, &
stem on the said driver bs projecting through a longitudinal slot 6 in the bracket D¹,
and through a slot be in the end of the bar b; this stem has a collar 67 (Figure 25),
and the end of the arm b is clamped between the said collar and a thumb nut 65
adapted to the screw threaded portion of the stem. It is important that the
driver 6 should be secured to the bar & in such a position that the proper space.
may intervene longitudinally between the acting faces of the drivers b², 63, and the
ends of the shuttle; this proper relation of the parts to each other must exist
before the driver bs can be secured to the arm b', and to obtain this result I enlarge
the inner end of the slot 6, and so adapt the nut to the said slot that it can only
bo turned when it occupies a position within the enlargement of the slot (see
Figures 25 and 26).
The shuttle bis provided with a cap or cover 61 (Figures 6, 27, 28, and 29)
connected to the body of the shuttle by means of a bayonet joint fastening,
comprising pins 61% on the cap and slots b in the body of the shuttle, so that the
said cap can be readily removed and replaced (see Figure 29). The thread passes.
from the interior of the shuttle through an opening in a central projection on the
cap 61; thence between the inner face of the said cap and a tension spring b¹³,
and finally through openings in the cap and shuttle body. This tension spring is
preferably made in the form of a seginent (see Figure 27), aud is secured at one
end to the inner face of the cap 1 by means of the screw 6, the adjustment of
the said spring being effected by means of a screw 61 which projects through the
cap-b12 of the shuttle, so that on removing the driver from the shuttle race b'
the screw may be manipulated_and_the tension varied without removing the
shuttle from the shuttle race; the regulation of the tension of the shuttle thread
can thus be accomplished without interrupting the formation of a perfect-and
continuous series of stitches.
I use an ordinary barbed needle c which is secured to the upper end of the
needle bar c¹, preferably by means of a tapered chuck, as shewn in Figure 5.
This needle bar c¹ is so adapted to bearings in the bracket D1 (Figures 4 and 5)
as to have free vertical reciprocating notion therein, the said bar as it is moved
vertically being also partially rotated through the medium of a scroll slot c³ in the
bar (see Figure 13) with which engages a roller carried by a stud c³ secured to the
bracket D' of the frame.
A screw threaded sleeve c' is screwed loosely on a screw threaded portion of the
needle bar c', Figure 5. The said sleeve has a projection adapted to a vertical
groove in the bracket D' of the frame, and is provided with a stud carrying a
flattened roller cf which enters a slot c7 in the end of an arm c³, Figure 1, pivotted
to the arm D of the frane at cº, and having a slot for the reception of a pin c¹³;
the latter is adapted to a slot in a lever co pivoted to the frame A at c" and
carrying an anti friction roller adapted to a cam groove c¹³ in the disc C upon the
driving shaft, as shown in Figure 1. By shifting the pin c¹s in the slots of the
arm and lever clo, the throw of the needle-bar may be increased or diminished
as desired, for the reason that the said arm and lever are pivotted at different
points, the variation being always at the bottom of the stroke, for when the needle
bar is at the top of its stroke the slots in the arm c and the lever c¹0 are directly
in line with each other, so that the pin c¹s can be shifted in the said slots without
causing any movement of the needle bar. When the needle bar is at the
bottom of its stroke however the slots are not in line with each other, and a
variation in the position of the pin ¢¹³ causes an elevation or depression of the said
needle bar.
The awl d is secured by means of a tapered chuck or otherwise to the lower end
of a stem d which is adapted to a bearing in a plate or slide e (Figures 4 and 17), and
is connected by means of a link d³ to a bar d² which reciprocates in bearings in the
front end of the frame A, the operation of the said bar d being effected by a cam
groove in the disc C' on the driving shaft through the medium of a lever d* pivotted

page_text: to the frame A by a transverse pin d³, and having a stud dª and roller adapted to
the cam groove in the said disc.
The plate e is adapted to lateral guides in a plate e¹ which is secured to the
frame A, and has a bearing for a vertical bar e; a bracket on this bar carries a
roller e adapted to a slot x (Figure 23) in a plate e; this plate is pivotted to the
plate e at the point e³, and has a segmental slot for the reception of the stem of a
thumb screw e', whereby the said plate e may be secured in any position to which
it has been adjusted (see Figure 18 and Figures 20 to 23). The plate e being
adjusted to such a position that the slot will be inclined in respect to a vertical
line, the reciprocation of the bar e will, owing to the ongagement of its roller e
with the said slot x, cause a lateral vibration of the slide e, the extent of this
vibration being governed by the angle or inclination of this slot ; this angle can
be readily determined by means of a pointer on the plate e in connection with a
segmental graduated scale on the plato e. As the feeding of the work is accom-
plished by the lateral movement of the puncturing awl, the extent of this movement
determines the length of the stitch, hence this provision for readily and accurately
regulating the extent of the movement.
The upper end of the bar e" has a stud e' which is adapted to a slot in one arm
of a lever e; this lever is hung or pivoted upon the transverse pin d³ of the frame,
and has on its other arin a stud and roller adapted to a cam groove e in the disc C
on the driving shaft, whereby on the rotation of the said disc the desired vertical
reciprocation of the bar e is effected.
The looper g (Figures 17 and 19) is carried by the short arm of a lover g',
pivotted at g² to the lower end of an arm g; this arm is pivotted at its upper end y'
to the frame A, and has an inclined slot for the reception of a roller on a stud go,
on one arm of a lover g7 pivotted to the pin d³. The other arm of the said lever
has a stud and roller adapted to a cam groove gº in the disc C. The long arm of
the lever gl has, at its upper end, an inclined slot go to which is adapted a stud g
on the bar e, so that as the lever g' is vibrated and the bar e reciprocated a
combined lateral and longitudinal movement, somewhat similar to that of an ordinary
four motion feed, is imparted to the looper g. The lateral movement of the said
looper is due to the swinging of the arm by the engagement of the stud go with
the inclined slot go, and the longitudinal movement is caused by the vibration of
the lever g' due to the engagement of the stud g" of the bar e with the inclined
slot go of the said lever g¹.
It is desirable in a machine of the class to which this Invention relates to hold
the leather or other material firmly to resist the action of the awl and needle while
the stitch is being made and yet permit the ready feeding of the said material.
When the presser bar is acted upon by a spring strong enough to firmly retain the
work during the sewing operation the feeding will be retarded in the absence of
mechanism for automatically raising the foot, and when a light or weak spring is
employed the material or work is not properly retained on the bed at all times.
Theso objections I overcome by using a light spring on the presser bar, and by
employing in connection with the said bar means whereby it may be automatically
locked and rigidly held in position between the feeding operations.
These devices are shewn in Figures 2, 7, 8, and 12, by reference to which it will
be observed that the presser foot f is secured to the lower end of a hollow bar f',
adapted at the lower end to a bearing on the frame A and at the upper end to
bearings on lugs f³, f², the portion of the bar between the said lugs being adapted
to a sleeve f. This sleeve has a tubular stem, which fits within a lug on the
frame A, and has an internal screw thread fitting the threaded front end ₤10
of a rod f; the rear end of this rod passes through and has its bearing in a
lug f on the frame A.
The projecting rear end of the rod f' has a collar f and an arm f'; the
latter is furnished with an antifriction roller at its end, and is acted upon by a
spring and by a cam fs on the disc C' carried by the driving shaft. Between
the feeding operations the arm f' is under the control of the spring fº, the tendency

page_text: of which is to turn the rod f* in the direction of the arrow 2, Figure 7, and as the
said rod is incapable of moving longitudinally by reason of the contact of its
collar with the bearing f the screw threaded end f10 of the rod will act upon
the screw threaded stem of the sleeve and cause the latter to exert pressure
upon the presser bar f' and bind it tightly in its bearings in the lugs f, thereby 5
preventing the elevation of the presser foot by any upward pressure on the material
or work. The action of the cam s upon the arm f' tends to turn the rod fi in
the direction of the arrow 1, Figure 7, thereby releasing the strain on the presser
bar when the work has to be fed forward. The bar f' is hollow, as above specified,
and within the said bar is a spring 13, which bears at its lower end against an 1
adjusting screw f15 and at its upper end against a block carried by a pin "; this
pin extends transversely through the upper lug, and through the bar f¹, slots f16
being formed in the latter to permit the elevation of the said bar, which operation
is effected by means of a lever f" pivoted to the frame A and acting on an
anti-friction roller f¹s carried by a stud on the bar f' (see Figures 2 and 12).
1
The thread is drawn from a spool i, adapted to bearings on the top of the
frame A, and acted upon by a suitable tension device, as shown in Figure 3; the
thread passes from the spool over a roller 7 in the frame A, thence around a roller
on a take-up lever L, thence around a roller h³ on the frame, and finally around the
rollers h³ and h to the looper g. The roller his carried by a bracket h¹ on a tube h², 2
which extends through the frame A, and the roller ³ is carried by a rod adapted
to slide in a bearing on the said tube, and acted upon by a spring, so that the
roller is free to yield as necessitated by the irregular action of the looper.
-To-maintain the rollers and h³ and the parts of the machine adjacent thereto
which act upon the thread at the proper degree of heat, a jet of gas from a pipe hº 2
is projected into the tube-h, the heat being thereby so deflected-downwards as to
come in contact with the looper, the awl, the thread guiding wheels, and the parts
adjacent thereto. The shuttle-race, shuttle drivers, and shuttle are also maintained-
at the proper degree of heat by a burner J, the flame from which is projected
against the underside of the bracket D¹, and is confined thereto by the side 3
ribs J¹, J¹.
The material or work k¹ rests upon a work plate k, which has the usual slot for
the
passage of the needle and awl.
The take up lever L is pivoted to the frame A of the machine, and is acted upon
by a cam L' on the shaft B in such a manner that a certain quantity of slack thread s
will be formed, which, as the needle descends after receiving a loop from the looper,
will be gradually delivered by the rise of the roller of the said lever L, so that
the thread will not be drawn through the hook of the needle as the latter
descends, but will be delivered at the same speed as that at which the needle
moves.
By theso means I prevent that excessive friction and wearing of the thread
which exist when the strain on the thread is not relaxed during the descent of the
needle.
The operation of the said machine is as follows, that is to say:-
Supposing the needle has drawn a loop of thread through the work in forming
a stitch, and that the rotary hook al is in position to enter the said loop, the other
parts of the machine will be in the following positions:-The awl will have been
moved laterally to the proper position for puncturing the work for another stitch,
the looper g will be almost in a direct line between the roller h and the hole in the
work in which the stitch is being made, the presser foot will be unlocked and the
shuttle will be passing from that portion of the race b' which is in the hollow
shaft a to that portion of the race which is forined in the bracket D'.
As soon as the hook a¹ has securely entered the loop the shaft a is moved
longitudinally outward to its full extent, in order to clear the needle and commence
by its rotation to lay the loop of thread on the segmental shield a', where it is
retained by the flange of the said shield. As the shaft a rotates the loop is taken
from the needle c, which then commences to rise, but before the point of the said

page_text: needle reaches the work the awl & will have pierced the same and fed it forward
for another stitch, the presser foot being then locked to hold the work firmly
on the work-plate. The shaft a having been retracted so as to remove the
hook a' and shield a from the path of the needle bar, the needle and awl rise
point to point through the work, and by the time the said needle and awl reach
the limit of their upward movement the segmental shield a² of the shaft a will
have distended the loop received from the needle, thereby drawing tight the stitch
previously formed, and providing for the passage of the shuttle which is driven
through the loop to interlock the shuttle thread therewith (sec Figure 15).
As the shaft a continues to rotate the loop is cast off from the shield a², and as
the shuttle is retracted, the end of the same strikes this loose loop and carries it
out of the way of the hook a¹.
Meanwhile the awl d has received a lateral movement to the extent of another
stitch, and the looper has been operated to form a fresh loop on the hook of the
needle c, the said hook being in the best position for receiving the loop, that is to
say, in such a position that the said loop will lie in the direction of the length
of the stitch as it is being drawn through the work.
As the needle descends it is, after leaving the work, partly rotated to properly
present the loop to the rotating hook a', which has by this time been cleared of
the previous loop, and is in a position to enter the loop just drawn down by the
needle.
The object of driving the shaft a by means of the differential gearing shown and
described is to impart a differential velocity to the said shaft, so that while the
hook al operates very quickly in removing the loop from the needle c, and dis-
tending the said loop for the passage of the shuttle, the remaining portion of the
rotation of tho hook is at such a slower rate of speed that ample time is afforded
for the proper operation of the shuttle, needle, awl, and looper.
The said shaft a is arranged at right angles to the direction of the feed, so that
the mechanism whereby the shaft is driven is entirely out of the way of the work
or material being sewn; this arrangement also ensures the pulling up of the stitch
by the action of the segmental shield a² in a direction parallel with the line of
the seam, thereby ensuring the production of neater work than could be produced
The hook a rotates in a
if the loop were drawn at right angles to the seam.
direction the reverse of that in which the work is fed, so that the loop of needle
thread will always be in a proper position for the entrance of the hook, the'
termination of the feed motion being always at the same point.
The segmental shield a in connection with the hook a' provides for the
formation of the loop for the passage of the shuttle, without drawing through
the work the excessive amount of thread demanded in making the loop in ordinary
lock-stitch waxed thread sewing machines, the amount of thread drawn through
the work in my improved machine being but little if any greater than in an
ordinary chain stitch machine. The shield a² also serves the purpose of drawing
up or tightening the stitch previously formed, thereby removing the strain from
the needle, and permitting the use of a much lighter needle than can be used
when the stitch has to be drawn up by the needle itself, the only function of
the needle in my improved machine being to catch the loop from the looper, and
draw it through the work.
Although I prefer to use the awl d for puncturing and feeding the material or
work, the main features of my Invention may be embodied in machines in which
the needle punctures the material, and either feeds the same or works in con-
junction with independent feeding mechanism; moreover the barbed needle cand
rotating loop catching hook a' may be used in connection with a device other than
the shield a for opening the loop and drawing up the stitch; but I consider the
shield the simplest and most effective means that can be devised for the above
purpose.
Having thus fully described the said Invention as communicated to me by my

page_text: foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,-
First. The combination of a barbed needle, a looper, and a shuttle, and
mechanism for operating the same with a loop-catching hook, and means for
rotating the said hook with a variable velocity, substantially as above set forth
and for the purpose specified.
Second. The combination with the frame of the machine of the barbed needle, the
looper, and the shuttle, the mechanism for operating the same, the shaft a having
a book and shield, and the means for rotating the said shaft at a variable velocity,
substantially as and for the purposes specified.
Third. The combination of the hook a¹ and means for rotating the same with
the needle, the looper, and means for vertically reciprocating and partially rotating
the said needle, as above set forth and for the purpose specified.
Fourth. The combination with the shaft a provided with the rotary hook, and
the means for rotating the same of the adjustable screw stud or bolt a® and the
sleeve a³, whereby the proper longitudinal adjustment of the said shaft and hook.
may be effected, substantially as above set forth.
Fifth. The combination of the shuttle driver 63 having a projecting stem, the
thumb nut adapted to the said stem and the bar b having a slot be enlarged at its
inner end, as and for the purpose specified.
Sixth. The combination of a shuttle which has an internal tension-device, whose
regulating screw projects through the head of the shuttle with a shuttle-driving
device, part of which is removable to permit access to the regulating screw of the
_shuttle without removing the said shuttle from its race, as herein specified.
Seventh. The combination-with-the-frame A of the tubular shaft a, the shuttle
race formed-partly-in-the said tubular shaft and partly in the frame-beyond-the-
end of the same, the shuttle b, the driver b; working-within-the_shaft_a, the
driver adapted to that portion of the shuttle race which is within the frame,
and the external rod b', whereby the said driver 6³ is reciprocated, all substantially
as and for the purpose set forth.
Eighth. The combination of a barbed needle and looper and means for
operating the same, a revolving hook for catching the loop from the needle, and
spreading or opening the same for the passage of the shuttle, and a shuttle
driver adapted to act on both ends of the shuttle, but free from contact there-
with, so as to permit the slipping of the loop over either end of the shuttle, all as
above specified.
In witness whereof, I, the said Harry Mills, have hereunto set my hand and
seal, this Seventeenth day of March, in the year of our Lord One thousand
eight hundred and eighty one,