IMPROVEMENTS IN SEWING LEATHER AND OTHER THICK OR TOUGH MATERIAL, AND IN MACHINERY AND THREAD FOR THE SAME
Year: 1872

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
IMPROVEMENTS IN SEWING LEATHER AND OTHER THICK OR TOUGH MATERIAL,
AND IN MACHINERY AND THREAD FOR THE SAME."-A communication
from abroad by George Valentine Sheffield, of Providence, and
Godfrey Kaye Mellor, of Woonsocket, both in the County of
Providence and State of Rhode Island, United States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 7th February 1872.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN SEWING LEATHER AND OTHER THICK
OR TOUGH MATERIAL, AND IN MACHINERY AND THREAD FOR THE SAME," to be as
follows:-
This Invention relates to a new sewing machine and to a new method

page_text: of sewing, and is to be more particularly used on leather or other equally
thick or tough material, and relates also to a new kind of thread used in
such method of and machinery for sewing.
The object of the Invention is principally to do away with the tedious
process of and consequently complex mechanism for forming loops or
knots in the sewing thread, and in every respect to simplify the machine
to the fullest extent without reducing its utility and adaptability to
various kinds and manner of work.
The Invention consists chiefly in the employment of a peculiar sewing
thread which is made in alternate double-pointed or double-conical
sections, to be used so that the sewing hook will take hold of the thinner
part, and draw it through the hole prepared in the leather until the
thicker portion of the thread will be firmly wedged within said hole and
securely held.
The Invention also consists in the employment of a peculiar double
tube and thread feed, one tube rotating continuously while the other
oscillates to thereby ensure the requisite action; also in the arrangement
of a reciprocating awl for punching and feeding the leather, and of a
reciprocating hook or needle for drawing the thread through the hole in
the leather, and thereby completing the stitches.
The improved leather sewing machine consists of a supporting base
standing on legs and made of the proper size for holding the parts of the
mechanism that constitutes the machinery. On a projecting post of the
base is held an elevated platform which supports the needle and awl and
the devices for moving the same. A hollow post projects vertically from
the base, and is secured stationary thereto so that it cannot move or
turn up and down. It encloses within its bore two concentric tubes, the
interior tube carrying at its lower end a pinion which is by intermediate
gear wheels in communication with a vertical shaft, and receives con-
tinuous rotary motion therefrom. This shaft extends through the base
into the elevated platform, and is connected by bevel gear with a
horizontal shaft which receives motion from the driving shaft of the
machine. This driving shaft is revolved by means of a belt or other
device, and carries an adjustable clutch which connects by levers with a
treadle or handle whereby the machine can be thrown into or out of
The outer tube carries a pinion at its lower end, which gears into
a toothed segment on an oscillating lever, and imparts to the said outer
gear.

page_text: tube alternate rotations in opposite directions. The upper end of the
inner tube is covered by a perforated plate whose apertures are two in
number, one being through the centre and the other eccentric. The
upper end of the outer tube embraces in part that of the inner tube,
forming an annular flange on top of the latter tube, in which flange a
notch is made. The hollow post or horn in which said tubes are mounted
as above described does not extend up as far as the top of the outer tube,
and is therefore not in the way of the operation. The vertically recipro-
cating hook or "needle" of the machine is secured in a holder attached
to a slide moving in guides at the front end of the elevated platform.
The slide is moved up and down in its guides by a crank pin which
projects from a disc or crank at the front end of the horizontal shaft
before mentioned. The needle is held and moved directly above the axis
of the inner tube. The perforating tool or awl projects downwards from
an arm of a vertical rock shaft which carries a crank at its upper end,.
and has its bearings in blocks mounted in the front part of the elevated
platform, in which they may have a short lateral motion. They arc
drawn outwardly by a spring, and are moved inward whenever a crank
pin on a rotary disc strikes a bell crank that bears against the blocks.
This disc receives motion from the horizontal shaft of the machine, and
has a cam groove cut into its edge, in which a pin projecting from a
sleeve that embraces the rock shaft of the awl (or from a circular or
other lever in which the said shaft is guided) fits and serves when the
disc is revolved to move the rock shaft up and down. A pin projecting
from the top of the disc will, whenever it strikes the crank at the upper
end of the rock shaft, vibrate the said shaft and carry the awl over the
end of the inner tube. A spring swings the rock shaft back away from
the tube when no longer under the influence of the said pin. The awl
is of prismatic form, with grooved sides and pointed end, and pierces a
hole of equal shape to its cross section. The needle is of equal shape
and cross section, size and shape, but has its edges notched downwards
close to where it commences to be pointed, thus forming barbs or hooks.
The thread to be used is made alternately thick and thin, thus forming
double conical sections. The intention is by taking hold of a thin part
to draw it doubled through the perforated leather, gradually drawing up
the thicker part, until finally the double thread is firmly wedged in the
leather and properly secured therein. Its thin ends may then be
smoothly cut off on the surface of the leather and the latter shaved or

page_text: The awl is next raised
The needle next descends
central hole in the inner
worn thin, the thread within it holding firmly as long as any is left.
This is the best and most reliable form of stitch yet produced. The
thread to be used for sewing is wound upon a spool which is hung under
the base of the machine, and is drawn through the inner tube and the
eccentric hole in the perforated plate at the top thereof. The leather to
be sewed rests on top of the outer tube. The awl is first swung over the
inner tube and carried down to pierce the leather eccentric to the axis of
the said tube. The blocks carrying its rock shaft are then moved laterally
so as to carry the awl over the centre of the inner tube, and thus feed
the leather sufficient for the length of stitch.
out of the leather and swung out of the way.
through a hole in the leather and enters' the
tube. The thread passing up through the hole eccentric thereto is by
the continuous rotation of the inner tube wound about the needle, so
that in the subsequent ascent of the latter it will take hold of the thread
by means of its barbs and draw it up through the leather. The continued
rotation of the inner tube serves to twist the thread while it is being
drawn, and to therefore firmly wedge it into the leather. The length of
sections in the thread and its feed are such that the needle will always
take hold of a thin portion of the thread and draw it up to let the thick
gradually follow in the manner herein-before indicated. Finally, the
needle cuts with its barb the thin part of the thread, and ascends clear of
the leather. A presser foot, controlled in its position by a crank shaft,
keeps the leather down. By means of a handle on the crank shaft the
presser foot can be raised when desired. The feed of the thread is
obtained from the oscillating or outer tube, which receiving the thread
in the notch in its flange will on every turn draw up as much thread as
is needed for one stitch, and constitutes a double section thereof. The
peculiar shaped hole made by the awl and fitted by the needle is entirely
filled and closed by the twisting of the thread, which is thus not only
lengthwise but also transversely firmly imbedded in the substances which
In case of sewing larger surfaces, such as the soles of boots and shoes,
et cætera, where the small support of the inner tube is insufficient, it is
proposed to substitute for the horn or post carrying the same a bent or
angular support. The inner and outer tubes in that case are continued
through the arms of the supporter, the several sections of said tubes
being geared together at the extremities by means of bevel gear wheels,

page_text: and which tubes operate at the upper end, substantially in the manner
above described, by the aid of a series of intermediate gear wheels which
actuate a short tube and disc revolving on the said tube placed at the
top extremity of the angular supporter. The said short tube is provided
with a concentric aperture and an eccentric aperture for the passage of
the thread, as and for the purpose before described. The thread is
drawn through the inner tube and over friction rollers at the angles.
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 7th August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
'
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of February, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alexander Melville Clark,
Her special licence that I, the said Alexander Melville Clark, my
executors, administrators, and assigns, or such others as I, the said
Alexander Melville Clark, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN SEWING LEATHER AND OTHER
THICK OR TOUGH MATERIAL, AND IN MACHINERY AND THREAD FOR THE SAME,' a
communication to me from abroad by George Valentine Sheffield, of
Providence, and Godfrey Kaye Mellor, of Woonsocket, both in the
County of Providence and State of Rhode Island, United States of
America, upon the condition (amongst others) that I, the said Alexander
Melville Clark, my executors or administrators, by an instrument in
writing under, my, or their, or one of their hands and seals, . should
"

page_text: particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Alexander Melville Clark, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the Sheet
of Drawings hereunto annexed, and to the letters and figures marked
thereon (that is to say) :—
This Invention relates to a new sewing machine and to a new method
of sewing, and is to be more particularly used on leather or other equally
thick or tough material, and relates also to a new kind of thread used in
such method of and machine for sewing.
The object of the Invention is principally to do away with the tedious
process of and consequently complex mechanism for forming loops or knots
in the sewing thread, and in every respect to simplify the machine to
the fullest extent without reducing its utility and adaptability to various
kinds and manner of work.
The Invention consists chiefly in the employment of a peculiar sewing
thread which is made in alternate double-pointed or double-conical
sections, to be used so that the sewing hook will take hold of the thinner
part, and draw it through the hole prepared in the leather until the
thicker portion of the thread will be firmly wedged within said hole and
securely held.
The Invention also consists in the employment of a peculiar double
tube and thread feed, one tube rotating continuously while the other
oscillates to thereby ensure the requisite action; also in the arrange-
ment of a reciprocating awl for punching and feeding the leather, and
of a reciprocating hook or needle for drawing the thread through the
hole in the leather, and thereby completing the stitches.

page_text: through the centre, the other o eccentric, as indicated in Figures 6 and 7.
The upper end of the oscillating tube e embraces in part that of d,
forming an annular flange on top of d. In this flange is a notch p, as
clearly shown in Figure 7. The hollow post or horn C does not extend
up as far as the top of the tube e, as appears in Figure 2, and is therefore
not in the way of the operation.
H is the vertically reciprocating hook or "needle" of the machine.
It is secured in a holder r which is attached to a slide s moving in
guides at the front end of the platform B. The slide s is moved up and
down in its guides by a crank pin t which projects from a disc or crank
at the front end of the shaft E. The needle is held and moved directly
above the axis of the tube d.
I is the perforating tool or awl. It projects downward from an arm u
of a vertical rock shaft J, which shaft has its bearings in blocks V, V,
and carries a crand W at its upper end. The blocks V, V, can have a
short lateral motion in the front part of the platform B. They are
drawn outwardly by a spring x, and are moved inward whenever a crank
pin yon a rotary disc L strikes a bell crank that bears against the
blocks. The disc L receives motion by intermediate gearing a², a², from
the shaft E, and has a cam groove 2 cut into its edge. A pin d²
projecting from a sleeve that embraces, the rock shaft J (or from a
circular or other lever M in which the shaft J is guided) fits into the
cam groove b³, and serves when the disc L is revolved to move the
shaft J up and down. A pin e² projecting from the top of the disc L
will whenever it strikes the crank W vibrate the shaft J, and carry the
awl over the end of the tube d. A spring, not shown, swings the shaft J
back away from the tube d when no longer under the influence of the
pin e².
f
The awl I is clearly shown in Figures 13 and 14. It is prismatic
with grooved sides and pointed end, and pierces a hole of equal shape to
its cross section, Figure 14.
The needle H is of equal shape and cross section, size and shape, but
has its edges notched downwards close to where it commences to be
pointed, thus obtaining the barbs or hooks f², which are shown in
Figures 9 and 10.
The thread N to be used is of the shape shown in Figure 15, that is
to say, made alternately thick and thin, thus forming double conical

page_text: sections. The intention is by taking hold of a thin part to draw it
doubled through the perforated leather, gradually drawing up the thicker
part until finally the double thread is firmly wedged in the leather and
properly secured therein. Its thin ends may then be smoothly cut off
on the surface of the leather and the latter shaved or worn thin, the
thread within it holding firmly as long as any is left.
and most reliable form of stitch yet produced.
This is the best
It is illustrated in
which is
The thread to be used for sewing is wound upon a spool
hung under the base A, and is drawn through the tube d and the
eccentric hole o, as shown. The leather to be sewed rests on top of the
tube e. The awl is first swung over the tube d and carried down to
pierce the leather eccentric to the axis of the tube d. The blocks V
carrying the rock shaft J are then moved laterally by the pin y and
crank z, so as to carry the awl over the centre of the tube d, and thus
feed the leather sufficient for the length of stitch. The awl is next
raised out of the leather and swung out of the way. The needle next
descends through a hole in the leather, and enters the central hole n
in d. The thread passing up through the hole o eccentric to n is by the
continuous rotation of d wound about the needle, so that in the sub-
sequent ascent of the latter it will take hold of the thread on the
barbs f, and draw it up through the leather. The continued rotation
of d serves to twist the thread while it is being drawn, and to therefore
firmly wedge it into the leather. The length of sections in the thread
and its feed are such that the needle will always take hold of a thin
portion of the thread, and draw it up to let the thick gradually follow in
the manner herein-before indicated and as shown in Figure 8. Finally
the needle cuts with its barb the thin part of the thread, and ascends
clear of the leather. A presser foot P, controlled in its position by a
crank shaft R, keeps the leather down. By means of a handle g² on R
the presser foot can be raised when desired. The feed of the thread is
obtained from the oscillating tube e, which receiving the thread in its
notch p will on every turn draw up as much thread as is needed for one
stitch, and constitutes a double section thereof. The peculiar shaped
hole made by the awl and fitted by the needle is entirely filled and closed
by the twisting of the thread, which is thus not only lengthwise but
also transversely firmly imbedded in the substances which it is to
hold

page_text: sliding shaft J for the purpose of piercing and feeding the leather, as
set forth.
11thly. The rock shaft J fitted through the blocks V, V, and combined
with the bell crank z, pin y, and disc L, substantially as herein shown
and described.
12thly. The disc L provided with the cam groove 6² and with the
and e³, whereby it serves to impart the three different kinds of
motion to the awl, as set forth.
pins
y
13thly. The combination in one machine of the tubes d, e, recipro-
cating needle H, and reciprocating vibrating awl I, all arranged to
operate substantiaily as herein shown and described.
14thly. The angular supporters S provided with the sectional tubes
d, e, and the connecting gearing, as set forth.
-
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Sixth day of August, in
the year of our Lord One thousand eight hundred and seventy-
two.
Witness,
JAS. O. DEWEY,
53, Chancery Lane,
London.
'A. M. CLARK. (L.S.)