IMPROVEMENTS IN SEWING MACHINES
Year: 1870

page_text: LETTERS PATENT to] James Henry Smith, of 200, Southgate Road,
Islington, in the County of Middlesex, Sewing Machine Maker,
for the Invention of "IMPROVEMENTS IN SEWING MACHINES."
PROVISIONAL SPECIFICATION left by the said James Henry Smith
at the Office of the Commissioners of Patents, with his Petition, on
the 12th October 1870.
I, JAMES HENRY SMITH, of 200, Southgate Road, Islington, in the
3 County of Middlesex, Sewing Machine Maker, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN SEWING MACHINES,"
to be as follows:-
These improvements relate to sewing machines in which a thread is
passed by a vertical reciprocating needle through the cloth or fabric, and
is secured therein by a second thread carried by a bobbin over which a
loop of the first thread is passed by a rotating hook, the two threads
being carried to produce a stitch known as the lock stitch.
These improvements can also be adapted to machines making the lock
stitch with a shuttle.

page_text: The said improvements consist, partly in the construction of machines
in which the device for operating the said needle and hook or shuttle
are permanently combined with additional mechanism for producing
either a single loop stitch, locked loop stitch, or lock stitch, separately,
alternately, or combined, the said mechanism being so constructed and
arranged that without detaching or removing the same, the machine
can be adjusted to form the single loop stitch, locked loop stitch, or lock
stitch. This additional mechanism consists, mainly, of a vibrating
guide or thread holder (the purpose of which is to push, hold, or guide
the cotton, so that the needle in its descent may pass inside, the loop
being formed by the rotating hook or other device when the locked loop
or loop stitches are required) which is pivotted to a portion of the plate
or framing, and is so arranged that it can be readily connected or
disconnected with a cam or other operating device carried by the
mandrell or other convenient portion of the machine. The thread
holder or guide can be thrown out of gear (when the machine with
cotton in the bobbin will make the lock stitch) by means of a lever
projecting from the machine which can conveniently be moved by the
operator while the machine is standing or working. The lock and lock-
looped stitches can be made by throwing the guide or thread holder in
gear by means of the said lever and putting an empty bobbin or shuttle
in the machine, it will then make only the loop stitch; the locked loop
stitch is made by the bobbin cotton being passed through the single
loop stitch which is held by the guide or thread holder as before
described.
The said improvements further consist of a vibrating or self-acting
tension by means of which an extra tension is put upon the thread at
a certain part of each revolution of the machine, thus diminishing the
liability to leaving long loops of thread whenever the material being
sewn is turned round, or when the machine is stopped or started again,
or from any other cause, and this is accomplished by means of an
excentric revolving on the mandrell (or any other device) and connected
to the stud upon which the tensions are placed, the said stud having
adjustable nuts or pad opposite to excentric whereby more or less
pressure can be put on the thread by means of a spring acting against
the roller or pully, washers, or flat spring where the cotton passes over,
between, or under to form the tension.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said James Henry Smith in the Great Seal Patent
Office on the 12th April 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HENRY SMITH, of 200, Southgate Road, Islington, in the County of
Middlesex, Sewing Machine Maker, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of October, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-fourth
year of Her reign, did, for Herself, Her heirs and successors; give and
grant unto me, the said James Henry Smith, Her special licence that I,
the said James Henry Smith, my executors, administrators, and assigns,
or such others as I, the said James Henry Smith, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein ex-
pressed, 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 MACHINES,"
upon the condition (amongst others) that I, the said James Henry
Smith, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should 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 James Henry Smith, 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 thereof, reference being had to the accom-
panying Sheet of Drawings, and to the figures and letters marked.
thereon, that is to say :-
My improvements relate to sewing machines in which a thread is
passed by a vertical reciprocating needle through the cloth or fabric, and
is secured therein by a second thread carried by a bobbin over which a
5 loop of the first thread is passed by a rotating hook, the two threads
being caused to produce a stitch known as the lock stitch..

page_text: '
These improvements can also be adapted to machines making the
lock stitch with a shuttle.
One part of my Invention consists in combining with such machines
certain mechanism permanently connected thereto, which, in operating
in conjunction with the needle and hook or shuttle will enable such
machines to produce at will either a single loop stitch, a locked loop
stitch or the ordinary lock stitch, such mechanism being so constructed
and arranged that without detaching the same the machine may be
made to form either of the above stitches, and to change from one
description of stitch to another, even while the machine continues in
motion.
The said mechanism consists, namely, of a vibrating guide or thread
holder actuated by a cam or equivalent device on the mandril or other
convenient moving part of the machine in such manner that on the
descent of the needle that portion of the loop thereof which is situated
immediately below the cloth plate is guided by the said thread holder,
so as to bring it into a position relative to the needle opposite to that
which it ordinarily occupies when making the lock stitch, whereby in
the case of the machines operating with a rotating hook the needle is
caused in its descent to pass inside the loop that is passing over the
hook, while in the case of shuttle machines the needle is caused to pass
inside a part of the loop which is pushed to one side by the thread holder
and held thereby after the shuttle has passed through it. The thread
holder, or guide, or an arm carrying the same is pivotted to a portion of
the plate or framing, and is so arranged that by means of a lever or
equivalent device it can be readily and instantaneously thrown in and
out of gear with the before-mentioned cam or other moving device while
the machine is either standing or working. If the thread holder is
thrown out of gear the ordinary lock stitch is made, if thrown in gear
when both upper and under thread are being used the locked loop stitch
is formed, and if thrown in gear with an empty spool or shuttle in the
machine an ordinary single thread loop stitch will be formed.
Another part of my Invention consists in the application to sewing
machines of a compensating tension, by means of which an extra
tension is put upon the thread at a certain part of each revolution of a
the machine, thus diminishing the liability of leaving long loops of
thread whenever the material being sewn is turned round, or when
the machine is stopped or started again, or from any other cause. And

page_text: this is accomplished by means of an excentric revolving with the spindle
or mandril (or any other device), and connected to the stud upon which
the tensions are placed, the said stud having adjustable nuts on the end
opposite to the excentric, whereby more or less pressure can be put on
the thread by means of a spring acting against the roller, or pulley,
washers, or flat spring, over, under, or between which the cotton passes to
form the tension.
Having thus set forth the nature of my Invention I will now proceed
to describe the best means I am acquainted with for carrying the same
into effect, for which purpose I shall refer to the accompanying Sheet of
Drawings.
Figures 1 to 5 shews my Invention as applied to a machine with
rotating hook, only so much of the machine being shewn as is necessary
to explain the nature of my Invention. Figure 1 shews a front view
of the machine with the before-described thread holder or guide thrown
out of gear; Figure 2 shews the same view with the thread holder in
gear, and in the act of guiding the thread as described. Figure 3
shews a side view of the thread holder in the same position as in Figure 2,
but with the needle somewhat higher up; Figure 4 shews a back
view of the mechanism with the thread holder in gear, but in its back-
ward position; and Figure 5 shews a plan with the several parts in
the same relative position as in Figure 4. Similar letters of reference
indicate the same parts in each of the Figures.
The thread holder or guide A (colored red) is pivotted by means of
the screw B to the cranked portion C₁ of the rocking arm C, (also
colored red) which in its turn is pivotted to the standard D of the
machine by means of the pin E. The arm C is acted upon by a spring
F (coloured black) pressing on the stud G so as to tend to keep the arm
and consequently the thread holder A in the backward position shewn at
Figures 1, 4, and 5. The arm C carries furthermore the contact piece H
(colored green) pivotted thereto at I, and the trigger lever J (colored
blue) pivotted to it at K. Lastly, upon the mandril L of the machine is
fixed or formed the cam M (colored yellow) for actuating the thread
holder.
When the thread holder A is to be brought into action the trigger lever J
is moved by hand so as to catch into the contact piece H and hold it in
the position shewn in Figures 2 and 4, in which position the cam M in
rotating will press against the contact piece, and will by this means force

page_text: the rocking arm C, and with it the thread holder A, over (against the
action of the spring F) into the position shewn at Figure 2. As the
thread holder A moves into this position the tail thereof in sliding
against an incline formed at D' on the standard D is pressed outwards,
thereby moving the beak A² of the thread holder slightly inwards. The
thread holder in performing this motion catches the thread O (Fig. 3).
of the loop that is passing over the hook P somewhat below where it
enters the eye of the needle Q, when this is in the position shewn at
Figure 3, and pushes it from its usual position in front of the needle to
the back thereof, and holds it there as the needle descends into the
position shewn at Figure 2, so that the needle in passing down enters.
inside the loop, and thus the locked loop stitch is made, or if there is no
thread in the spool R a simple loop stitch is formed. Immediately after
the thread holder has performed this operation it is caused to spring
back into the position at Figure 4; as the cam M on passing away from
the contact piece H allows the spring F to act on the rocking arm C, so
as to force it over into such backward position. At the same time the
beak A² of the thread holder is also caused to move outwards again into
its original position by the spring N attached to the tail A' thereof, which
spring acts so as to draw the tail inwards. When it is desired to throw
the thread holder out of action in order to form the ordinary lock stitch
the trigger lever J is simply depressed, whereby the contact piece H is
freed and is moved back by the rotation of the cam M into the position
shewn in Figure 1, without effecting any motion of the rocking arm and
thread holder which are thus kept always in the backward position by
the spring F. In order to steady the rocking arm C during its motion
it is formed with a curved slot at C which works over a screw S screwed
into the standard D. It is necessary for the perfect working of the above-
described mechanism that a small recess should be formed on the under-
side of the needle plate at the edge of the needle hole, as shown at T,
Figure 6.
Figure 7 shews a plan of an arrangement of the before-described
thread holder or guide as applied to a shuttle machine; D is the shuttle
box, on the under side of the cover of which is the thread holder A working
with a slot a upon the fixed pin B. The thread holder A after the
passage of the shuttle through the loop of the upper thread is caused to
advance from the position shewn in black lines to the position shewn in
red lines, thereby catching the loop of the upper thread and carrying it

page_text: entirely from the back of the needle at a to the front thereof. The
needle then descends and is thus made to enter the portion of the loop
retained by the thread holder A. This is then caused to move sideways
into the position shewn in blue lines, and is then drawn back into the
original position for repeating the operation. These motions of the
thread holder or guide A may be effected in various ways according to
the construction of the machine to which the thread holder is applied, in
the present instance they are effected as follows:-The thread holder is
connected to a lever C, working with a slot on a pin E, fixed to the
shuttle box or other part of the framing, the tail C¹ of this lever is
actuated by the passage of a pin F projecting from the shuttle carrier
or driver so as to impart to the thread holder the forward motion, while
the lateral motion is produced by a second lever G turning on a fixed pin
at g, and working with a finger G¹ in a notch in the lever C, C¹, and
actuat
by the passage of a second pin H on the shuttle carrier or driver.
The 1
pin E
G is provided with a spring knee joint at g' in order that the
moving in the direction of the arrow on the return of the
shuttl all depress the hinged portion without actuating the lever
itself. e backward motion of the thread holder into its original
O positiis effected by a spring I. The thread holder is thrown out of
gear by means of a sliding bar J on the shuttle carrier, which bar on
being slid by hand in the direction of the arrow draws the pins F and H
inwards by means of the slots j, j, so as to prevent them from acting
upon the levers.
Figure 8 shews a cross section of the frame X and spindle S of a
sewing machine with my before-described compensating tension applied
thereto; S is the spindle of the machine actuating the needle bar, upon
this spindle is an eccentric or cam T which in revolving with the spindle
acts upon the hooked portion U₁ of the tension stud U, in such manner
as to depress the same and thus to cause it to put an extra compression
upon the tension spring V of the tension washers or pulley W at the
moment when no thread should be drawn off the reel.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be understood that I do
not limit myself to the precise arrangements for carrying my Invention
into effect as herein-before described and shown on the accompanying
Drawing, as these may be variously modified without departing from
the essential feature of the Invention, but what I claim is,―

page_text: First. Combining with lock stitch sewing machines working, with a
rotating hook or a shuttle a thread holder or guide so arranged and
actuated by the machine as to catch the loop of the upper thread as the
needle descends, and to move the same so as to bring the loop into a
position relative to the needle opposite or nearly so to that which it
ordinarily occupies, substantially as and for the purposes herein-before
set forth.
Second. So arranging the thread holder or guide A that it can be put
in or out of gear with an actuating cam, crank, lever, or equivalent
device by the motion of a hand lever or slide, substantially as herein-
before set forth.
Third. Combining with the tension pulley, washers, or spring of
sewing machines a compensating tension mechanism so arranged as by
means of an eccentric or equivalent device to put an additional tension
on the upper thread when no thread should be drawn off the reel,
substantially as herein-before described.
In witness whereof, I, the said James Henry Smith, have here-
unto set my hand and seal, this Twelfth day of April, in
the year of our Lord One thousand eight hundred and seventy-
one.