IMPROVE- MENTS IN SEWING MACHINES, CHIEFLY DESIGNED FOR USE IN THE MANUFACTURE OF BOOTS AND SHOES
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by William Henry Abbott at the Office
of the Commissioners of Patents on the 23rd August 1878.
WILLIAM HENRY ABBOTT, of Harrow, in the County of Middlesex.
" IMPROVE-
MENTS IN SEWING MACHINES, CHIEFLY DESIGNED FOR USE IN THE MANUFACTURE
OF BOOTS AND SHOES."
This Invention relates to improved machinery chiefly designed for sewing the
soles of boots and shoes, the said machinery being also applicable for sewing thick
pieces of leather other than those used for boots and shoes.
In a machine constructed according to this Invention the needle passes through a
large thickness of leather and makes a regular and close stitch, and by the use of
the said machine I am enabled to sew through considerable thicknesses with perfect
tension and regularity.
A machine constructed according to this Invention comprises a stand forming the
body, with a cast-iron table which is itself fixed at a suitable height, or any other
table whatever. An inclined thread-carrying support rises to the needle, and serves
as a support to the leather being sewed.
Motion is transmitted by means of a pedal to a horizontal shaft placed at the side
and at the lower part of the stand or frame. This shaft is furnished with several
eccentrics and with a reversible cain. One of these eccentrics, the extremity of
whose stem or rod is above the top of the machine, actuates a lever at its centre.
The point of attachment of this lever is supported in such a manner that at each
revolution of the shaft it is slightly moved.
To weaken the effect of the dead-point of this lever a spring pressing on a shoulder
fixed to its attachment rod tends to cause it to resume its upper position at each
revolution of the machine. The other extremity of the lever acts on the neck of a
tube serving as a guide to the needle. This part receives a rising-and-falling move-
ment, varying according to the thickness of leather in contact with the needle. In
the interior of the said tube is a rod which controls a closer situated parallel to the
needle, and the object of which is to cover the notch of the latter in its upward.
movement.
The object of covering the notch of the needle is to prevent the stitch which has
just entered the leather from being drawn outside to the following stitch,

page_text: A central rod receives its movement from a rocking lever; a bell-crank movement
receiving the pressure of a tail-piece, causes the downward movement of the said
lever.
The rising of the said closer is effected by the top of the head of the needle bar,
which strikes against a false shoulder fixed on the central stem or rod.
A revolving head is placed in a hollow part provided above the junction of two
arched arms forming the stand or frame. A small toothed fly wheel fixed on the
same axis as this revolving head causes the said head to rotate.
This part of the machine may be driven either by hand or automatically, its
object being to produce the rotation of the looper in a constant ratio with the rota-
tion of the needle while fastening the thread in the notch; this arrangement permits
sewing in a circular direction and in a continuous manner... This, advantage is very
important in the manufacture of boots for the navy.
On the said horizontal shaft is another. excentric, the rod of which controls a lever
furnished with a small claw penetrating a toothed sector. This sector is itself
attached to the extremity of another lever the fork of which causes the upper ring
on the said revolving head to slide. The other end of the said lever rests on a fixed
shoulder placed on a vertical rod... This rod serves to regulate the height of the
needle bar according to the thicknesses of the leather. The said ring, mounted on
an internal rod which serves as its guide is caused to follow the movement of the
whole of the mechanism. Another ring is furnished like the one above-named with
an internal rod, which unites it to the revolving head and compels it to turn
with it.
The descending movement imparted to a lever commanding this ring causes the
latter to fall and to meet with its internal rod, a small spring tappet striking on the
back of the presser foot which is carried to a very little distance from the needle
closer.
The use therefore of the two rings is as follows; that is to say, the first raises or
lowers the presser foot, and the second causes it to advance towards the needle... It
will be readily understood that. when the point of this presser foot in being lowered
rests on the leather and penetrates it slightly, the forward movement taking place
immediately the leather is drawn along, and is placed under the needle just at the
desired point for sewing. The hand of the operator has only to hold the sole or,
other piece, and to guide it according to the sinuosities of the piece being sewn.
When the ring rises it draws the rod of the said tappet, and the presser foot resumes
its original position.
""
In order to firmly grasp the object being sewn, and keep it against the thread-
carrying stay or support, a second presser foot is fixed to the first one, by, which it
is actuated, its end coming behind the needle.
The disengaging of the said small claw is effected by means of a bell-crank move-
ment connected to the stem or rod of an eccentric fixed on the aforesaid horizontal
shaft. A small spring brings back the claw to the teeth of the said notched
sector.
To the extremity of the shaft is fixed a cam controlling jointed "mechanism, the,
object of which is to cause the to-and-fro movement of a toothed piece or rack.
This rack controls a pinion, forming part, of the mechanisin, the working of, which
will be lierein-after described...
i
The thread-carrying support or stay is traversed throughout by a rod joined to
the mechanism just mentioned. The upper part of this rod is toothed, and takes
into a small piece which forms the looper. The thread taken on a reel passes through
the looper excentrically.
At each revolution of the machine the needle descends, inakes its stitch, and brings
up the loop of the following stitch. At the same time the rack. operates, and has
caused the rod controlling the small looper to make a complete revolution, This,
looper has one-third more teeth than the small wheel or toothed upper end of the
rod, in order to cause it to make only two-thirds of a turn at each revolution of the
said small wheel. The rack in returning to its original position causes the wheels
P
I

page_text: which it controls to turn in a contrary direction; the toothed rod and the looper,
influenced by the same movement, have also changed their direction of rotation.
The object of this alternating movement is to present the thread guided by the
looper in the position that it ought always to occupy in connection with the notch
in the needle, so that this thread should in no case receive the slightest twist.
17
In the above description I have shown the connection of the looper with tho
general working of the whole machine. It is essential to actuate it also by hand,
that is to say, to make it rotate according to all the movements of the said revolving
head, which is moveable on its axis, and can with the assistance of a fly wheel
which surmounts it, turn at the will of the operator, in order to follow the sinuosities
of the sewing. The connection of the movement of the revolving head with the
wheel mechanism of the rod is effected by a Vaucanson chain. The said fly wheel
is toothed on its outside, and it transmits to the intermediate chain pinion the
rotation imparted. This pinion is surmounted by an ordinary gear wheel engaging
with a small wheel fixed on the vertical shaft which it operates.
A bevelled pinion fixed on the lower extremity of this shaft actuates gearing
mechanism comprising the following parts; that is to say,
A conical plate, the lower socket of which is prolonged by two wheels cast together.
The last one of. these two wheels. receives sits rotatory movement from the said rack.
The wheel surmounting it gears with a small pinion placed excentrically under the
conical plate, and by the said axle transmits its movement above the plate in order
to actuate the central rod of the thread-carrying stay or support, the lower part of
which is fixed on the pinion.
H
..
The useful position of the rod is therefore invariably determined in working the
revolving head either automatically or by hand, and even in the case of the two
inovements taking place simultaneously. The proportion of the teeth of the parts
composing the movement. is so arranged that disarrangement is rendered iin-
possible.
I may modify the construction of the above-described machine as follows; that
is to say: The said vertical shaft joining together the upper and lower mechanism is
terminated at the top by a bevelled gear wheel actuating a similar wheel placed at
the extremity of a horizontal axle. The other extremity of this axle has a small
conical pinion actuated by a wheel three times as large, the latter replacing the
wheel with endless chain herein-before described. By means of this arrangement,
when the needle has penetrated the leather the looper revolves around the latter
for about a quarter of a turn of the rotation of the driving shaft, and places imme-
diately the thread into the notch of the needle, then remains stationary during the
completion of the revolution of the said shaft. At the same time the needle has
made its ascending movement, and has descended again. The looper makes one-
fourth of a turn, replaces the thread in the notch of the needle, and remains
stationary until the needle has risen and descended a second time to make the
following stitch.
I modify the motion of the lever as follows, that is to say:-A cam gives the
necessary movement to a bell-crank movement, one of the arms of which is con-
nected to a vertical rod. A jointed part controls the lever communicating with the
lower ring. At the extremity of the rod is a claw working in a toothed sector or
catch, which terininates the lever just mentioned. In its movement the rod acts on
the claw, which in its descent works in the toothed sector. This side of the lever
is lowered, and the other extremity rises whilst acting on the presser foot, joined to
it by the upper ring.
When the rod from one of the excentrics has come to the lowest part of its
course it catches by a finger on the end of another lever attached by an arm to a
rod, and causes the catch to be detached.
The lever connected with the upper ring rises and descends under the action of
the said claw and of a spring. The presser foot being attached to the said upper
ring, which is embraced by the end of its lever, is thereby pressed upon the work
and raised from the same,

page_text: The aforesaid vertical rod, to which one of the arms of a bell-crank motion is
connected, serves equally to determine the length of the stitch. The actuation of
the presser foot necessary for this result is obtained by the lever communicating
with the lower ring connected to the rod at the aforesaid jointed part. The other
end embraces the lower ring which actuates by a lever a small spring cleat or tappet
striking on the back of the presser foot.
According to another part of my Invention I further modify the construction of
the, machinery chiefly with regard to the gear wheels at the lower part of the
machine, which act on the looper rod and the vertical axle actuating the upper part
of the mechanism:¸
1
The machine constructed as herein-before described does not permit the use of
beaked anvils or work supports which are not straight, but it is very important,
in sewing elastics, for instance, to construct the same of other form than straight.
By reason of this modification of the machine I am enabled to use the said part
of other form than straight, and at the same the motion of the looper is perfectly
regular, and the said modification in nowise complicates the machine.
In carrying this part of my said Invention into practice I provide an independent
stand or frame in which is a cam whose object is to actuate a rack. This cam is
acted on by a bevil gear wheel. The object of this rack as herein-before described
is always to give to a small pinion which gears with it an alternating movement,
which is communicated to the looper by means of a shaft and of small bevil gear
wheels, in order that the thread which this looper guides should always be presented
invariably to the position which it ought to occupy as regards the notch in the
needle. To actuate the looper by hand, and apply to it a rotation in direct propor-
tion with all the movements of the revolving head, I always employ a vertical shaft
terminated at the lower part by a pinion which gears with a wheel on an excentric
shaft having wheels at the ends gearing with corresponding wheels, so that all this
combination of mechanism shall act on the looper by the motion of the machine as
well as by the revolving head actuated by hand.
It will be seen from the above description that the form of the said parts and
their arrangement are modified in comparison with the machine first herein
described, but that the action remains practically the same, although considerably
improved, as by means of the said modifications the sewing of clastics on boots can
be readily performed by reason of the beaked anvil or work support which perfectly
fits the bend at the back of the boot, which advantage is impossible with a straight
anvil or work support.