AN IMPROVED METHOD OF AND MACHINERY FOR UNITING PIECES OF LEATHER OR OTHER MATERIALS, WHICH INVENTION IS APPLICABLE FOR SEWING THE SOLES OF BOOTS AND SHOES, FOR MANUFACTURING HARNESS, AND FOR OTHER LIKE PURPOSES
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office of
the Commissioners of Patents on the 4th October 1876. A communication
from abroad by Ellis Drake, of Stoughton, Machinist, and John Harvey Wright,
of Nabant, Merchant, both in Massachusetts, United States of America.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED METHOD OF AND MACHINERY
FOR UNITING PIECES OF LEATHER OR OTHER MATERIALS, WHICH INVENTION IS
APPLICABLE FOR SEWING THE SOLES OF BOOTS AND SHOES, FOR MANUFACTURING
HARNESS, AND FOR OTHER LIKE PURPOSES." A communication.
This Invention relates to an improved method of and machinery for uniting the
soles and uppers of boots and shoes, making harness, and the like.
In uniting the soles and uppers in the manufacture of boots and shoes by the
ordinary chain stitch, the needle while forming the stitch occupies a portion of the
space of the hole, and consequently either the thread forming the stitch has con-
siderable play in the leather, or the space left by the withdrawal of the needle is
filled in part by wax, and the work is not satisfactory, first, because the needle holes
are liable to allow the entrance of water into the shoe; second, when the ends of the
loops become worn off the portion of the thread in the space or hole is liable to be
drawn out, and as a consequence the work is liable to come to pieces; third, the
loops occupy so much space upon the surface of the sole that it is necessary to cut
a comparatively wide and deep channel to receive them, and in so doing a con-
siderable portion of the wearing surface of the sole is destroyed, besides rendering
the boot or shoe very undesirable when the lip of the channel becomes started up,
and finally the stitch lacks firmness and compactness, which are very necessary to
insure the durability of hand sewed work.
The object of my Invention is to remedy these objections by the formation of a
stitch, which shall fully and absolutely fill up and occupy the space of the hole
formed by the needle, and become in fact an elastic peg of four strands, and having
only a single thread exposed upon both surfaces, and in the production of a machine
constructed and adapted for forming my new stitch.
In the construction of this machine I employ an eye pointed needle in connection
with a work supporting arm adapted to enter any portion of the interior of a boot
or shoe,
A reciprocating looper for the under or stitch thread co-operates with a
C

page_text: guide for said thread, so that a loop of the under or stitch thread will be passed
through a loop of the needle thread, and in which the looper and the guide aro
independently carried by the work supporting arm.
In the operation of these parts the under thread forms the stitch loop, while the
needle thread serves as the carrier for said loop. In this combination the employ-
ment of an eye pointed needle enables me to use two threads with a work supporting
arm adapted to enter the interior of a boot or shoe.
In the combination with the eye pointed needle, the looper thread guide, work
supporting arm, and presser foot, I employ a swiveling feed device mounted upon
pivoted arms, the object of which is to enable me to sew any portion of the
interior of a boot or shoe by the employment of two threads, from one of which
the stitch loop is formed. In the formation of this stitch loop it is necessary that
it should be automatically regulated in length to correspond with the thickness of
the work, and this I accomplish by a new combination of mechanism in connection
with the feed device, presser foot, and looper, whereby the thickness of the work
determines the length of the stitch loop. In effecting this object I make the
connection of the feed device and presser foot with the looper connections at a point
coincident with the axis of the needle bar, whereby the vertical movement of the
presser foot accurately determines through the functions of a double cam arranged
between the presser foot and the looper, the backward movement of the looper and
consequently the proper length of the stitch loop, while at the same time this
axial connection allows the presser foot and feed device to be swiveled in accordance
with the required direction of the work, such as sewing round the toe and heel of a
shoe. Connected with this automatic adjustment I combine an independent adjust-
ment to adapt the machine to the various classes of work for which the stitch is
applicable.
In some classes of work it is desirable to conceal the ends of the stitch loops that
the face of the stitches may give the appearance of hand-sewn work, while in other
classes of work where the face of the stitch is not exposed to view in wear, and
where greater strength is required, the ends of the stitch loops may project beyond
the surface of the work, and are subsequently riveted in the operation of rubbing
down the seam formed thereby.
The independent adjustment referred to is to conform the length of the loop to
these conditions, and when in use this adjustment is made, the lengths of the loops are
determined automatically the same as if they were equal in length to the thickness
of the stock.
The feed points are provided with double slots, and so connected with the presser
foot and the needle bar that a downward and forward motion will be given them at
the same time to feed the work.
The connection of the looper and presser foot with the double cam is made by a
yoke, through which the said double cam imparts the proper movement to the looper.
These movements are peculiar, in order to form and give the stitch loop the right
length and cast it off.
The looper and thread guide are arranged to operate on opposite sides of the
work supporting arm, and both these devices are somewhat peculiar in construction
to adapt them for joint operation with an eye pointed needle, and the small end of
the work supporting arm.
A marker or creaser and feed point are combined in a single device for use
in place of the feed points, and in connection with the presser foot, feed arm, and
needle bar, so that the movement of the needle bar operates the creaser and the
feed points which are formed thereby.
In uniting the uppers to the soles of boots and shoes two threads have been
employed on what is known as "turned work" with a "lock stitch" by the employ-
ment of a shuttle, while a single thread has been used in connection with a barbed
needle to form what is known as the "chain stitch." But the employment of two
tbreads for forming a stitch which passes directly from the exterior to the interior
of a boot or shoe on its bottom has not hitherto been done in sewing machines to

page_text: my knowledge, and this is the distinguishing feature of my Invention in connection
with the peculiar stitch formed by my machine.
The reciprocating needle bar is mounted in guides in the head of the machine, and
operated by a pin or cam upon the end of the driving shaft working in a slotted
cross plate secured to the needle bar. Upon the lower portion of the needle bar is
secured a collar, which may be adjusted vertically thereon to operate and regulate
the feed device in connection with a shoulder on the needle bar above the collar.
The said feed device consists of two feed points secured near their front ends to
the presser foot by means of bolts passing through slots in the feed points, and
connected at their outer ends to the lower end of a curved feed arm in a similar
manner, so that the action of the two slots will allow the said points to work
freely thereon, and rise and fall at proper times during their backward and forward
motions.
The feed arm is pivoted between the ends of the supporting arms, which are
attached to a plate projecting from the lower needle bar bearing. The feed arm is
in the form of a bent lever, and passes through the presser foot arm, and to its upper
end is pivoted a clutch or coupling whose upper end embraces the needle bar above
the collar.
The presser foot is attached to and carried by a rod, which moves vertically in
guide plates pivoted to and extending from the upper and lower bearings of the
needle bar, while a stem rising from the upper end of the presser foot arm serves as
a bearing for a spring secured in a vertical tube. A vertical rod operates with the
feed device, and together with the presser foot and the tube confining its pressure
spring is secured to and carried by the said pivoted plates, so that the feed device
and presser foot can be given a half revolution around said needle bar and inde-
pendently of the same.
The needle has an eye for carrying the upper thread, and is arranged in com-
bination with a work supporting arm which enters within the boot or shoe and
carries the stitch thread, and I am enabled to employ two threads in uniting the
soles and uppers of boots and shoes by passing the stitch from the outside to the
inside of the work, and reaching any part of the work. This advantage results
from the use of the eye pointed needle looper, thread guide, and work supporting
arm in the formation of my improved stitch loop.
I provide the machine with a lifter, by which the presser foot.and the feed device
can be lifted from the work. The "throw" of the feed points which determines the
length of the stitch is adjusted by means of the aforesaid collar on the needle bar
by raising or lowering the said collar.
A double cam is secured on the cam shaft, and works within a yoke secured to
a rod passing downward through the frame, and connected at its lower end to a bell-
crank lever which is connected with and transmits motion to the looper and thrend
guide. To the upper side of this yoke is attached a short rod, which passes upward
through a guide plate, and connects with a forked lever pivoted to the top of the
machine. The said rod is surrounded with a spiral spring which presses upon the
yoke, and gives its rod its downward movement. The forked lever is also connected
to the presser foot rod, and its point of connection must be in the line of the
axis of the needle bar; the said bell-crank lever is connected to and operates the
looper.
.
A double cam gives four motions for each stitch in succession to the yoke and
looper rod, and these movements are transmitted to the looper.
The looper is carried by and lies along the side of an upwardly inclined
work supporting arm, and is held in position by a screw which passes through a
horizontal slot.
The thread guide is also carried by the work supporting arm, and is arranged on
the side thereof opposite to the looper. It consists of an arm pivoted to the side of
the work support and connected to a spring, the normal position of which is to
maintain the thread guide in its retracted position. The front end of this arm is
bent at right angles, and has an eye, and passes through an opening in the work

page_text: ·
support directly below and in front of the needle passage, and carries the under
thread. Near the pivoted end of the thread guide and projecting from the spring
is a stud extending through an aperture in the work support, and coming directly
opposite a recess on the under edge of the looper. The said stud is made to operate
the thread guide and cause its eyed end to approach and meet the looper as it
moves forward, so that it can receive the thread, and recede again after the loop is
taken.
The stitch loops are formed of lengths corresponding to the thickness of the work
operated upon, by means of devices operating automatically in combination with the
presser foot, and the devices for operating the looper, and this result is governed by
the heighth of the presser foot from the surface of the work support. These devices
consist of a lever connected at one end with the presser foot rod in the line of the
axis of the needle bar, and at the other end with the looper through the yoke and
rod, and the bell crank. The adjustment of the lever to depress its cam connected
end will make the loops longer, while the elevation of such end of the lever will
make the loops shorter and correspondingly must be the backward movement of
the looper, there being no variation in the forward throw of the looper to take the
loop. The connection and co-operation of the devices by which this is determined
are of simple construction, and extend from the presser foot above the stock to the
looper below the stock, and in connection with a loop formed by a needle thread
from above, and an under thread from below the work. The vertical guide rod of
the presser foot carries on its upper end a cranked coupling, whose upper crank
portion extends over the end of the lever which connects with the double cam yoke.
Through this crank coupling extends downward an adjusting screw carrying on
its lower end a flanged collar, which is embraced by the front forked end of the
said lever. The looper rod is made adjustable by means of a screw sleeve and lock
nut union with the yoke rod, so that by adjusting the screw sleeve the looper hook
is made to have its proper relation with the thread guide and the needle.
•
The adjustment of the aforesaid lever serves another important advantage. In
different classes of work it is desirable to conceal the ends of the stitch loops
within the work, while in other classes of work it is advantageous to have the
loop ends project beyond the surface. This I effect by adjusting the lever screw to
make the looper have a greater backward movement than the thickness of the stock
would produce, and thereby give greater length to the stitch loops, and the desired
projection of the ends thereof beyond the surface of the work. The reverse adjust-
ment of these parts gives loops of less length than the thickness of the stock, so as
to conceal the ends of the stitch loops.
One of the cams has two separate and distinct acting points of unequal radius.
That portion of the said cam farthest from its centre is to project the looper point to
engage with the under thread to form the stitch loop, while the second or lesser
projection of the said cam serves to give the looper a quick forward movement for
casting off or releasing the loop from its barb. The portion of the cam between its
acting points is concentric with the driving shaft, and gives no movement to the
looper while the depression between the acting points allowes the looper to be forced
back by the action of the spring upon the aforesaid yoke, and carry with it the
stitch loop to its proper length.
I provide the said machine with a device for taking up the needle thread, which
device consists of a lever carrying a grooved roll at its end, and held in position by
an adjusting spring that may be set to press with more or less force upon the thread
by means of a set screw, by which the take up is attached to a hanger secured to
the frame. The needle thread passes round the said roll, and a grooved roll on the
collar of the needle bar, and the take up pressure is made upon the thread between the
two guide rolls. The needle thread is supplied from a spool fitted with a tension
device consisting of a notched spring pin, so set that its notched end will engage the
periphery of the spool, and give the desired pressure or tension thereon. The thread
for the stitch loop passes through the guide from the spool.
The stitch is formed by the lower thread, the upper or needle thread serving as

page_text: the carrier for this lower or stitch thread. This is done by first passing the upper
thread through the work by means of an eyed needle and then drawing a loop of
the under thread through the loop of the upper thread formed by the recession of
the needle. The under thread is then released by the forward movement of the
looper, and is drawn up into the work by the return of the needle thread in the
form of four strands, and in which the looped ends of the loop proper is suspended
at the point in the needle hole by the needle thread.