Improvements in Sewing Machines.
Year: 1890

page_text: Date of Application, 27th May, 1890
Complete Specification Left, 15th Oct., 1890-Accepted, 15th Nov., 1890
PROVISIONAL SPECIFICATION.
Improvements in Sewing Machines.
I EDWARD KOHLER of 81 Guilford Street, Russell Square in the County of Middle-
sex, Engineer, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to render shuttle sewing machines of any type capable
of producing either a lock stitch or chain stitch, at will.
In carrying out my invention, I combine with the shuttle machine, a reciprocating
loop holder, which is situated below the throat plate, in a recess formed therein to
receive it, and above the shuttle. This loop holder consists of a plate having at one
end a fork and a projecting cam surface, and at the other end a socket.
The loop holder is reciprocated transversely of the machine by means of a bell
crank arrangement provided with a pin, which takes into the socket, and connected
to an excentric on the vertical or other rotating shaft, which (as the shaft rotates)
rocks the bell crank.
The loop holder has also a lateral movement, due partly to the action of a spring
and partly to the action of the projecting cam surface, which, as the loop holder
advances, strikes against the feed log, and moves the loop holder to one side against
the pressure of the spring.
The loop holder, as it advances, passes to one side of the needle to take up the loop,
and the lateral movement is required to present the loop to the descending needle for
the next stitch.
The loop holder actuating mechanism will be so arranged that it may readily be
disconnected when required.
When it is desired to make a chain stitch, the spool is preferably removed from
the shuttle, and the connection is made between the loop holder and the excentric.
As the machine is worked, the shuttle passes through, and opens out the loop,
which, as it leaves the heel of the shuttle, is caught by the advancing fork of the
loop holder, which holds it open, and brings it into position to receive the needle
at its next descent.
When it is desired to make a lockstitch, the loop holder is brought to its most
forward position, and the actuating mechanism is disconnected by which means the
loop holder becomes fixed in its forward position, and acts as a kind of additional
throat plate. The spool is then replaced in the shuttle, and the work may be carried
on with a lock stitch.
Dated this 97th day of May 1900
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Sewing Machines.
1 EDWARD KOHLER of 81 Guilford Street Russell Square in the County of
Middlesex, Engineer, do hereby declare the nature of this invention and in what
manuer the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
The object of this invention is to render shuttle sewing machines of any type,
capable of producing either a lock stitch or a chain stitch at will.
In carrying out my invention, I combine with the shuttle machine a reciprocating
loop holder, which is operated by suitable mechanism (when it is desired to make a
chain stitch) to take the loop off the shuttle (the spool thread being removed), to
hold it open, and to bring it, while open, into position to receive the needle at
its next descent.
..

page_text: In the accompanying drawings,
Fig. 1 is a plan view of the table of a shuttle sewing machine, with loop holder
adapted thereto.
Fig. 2 is an underside plan view, showing the mechanism for actuating the loop holder.
Figs. 3 shew in plan and elevation the loop holder detached.
Figs. 4 shew in plan and elevation the feed dog detached.
Figs. 5 show the thread plate in plan, underside view, and section.
Fig. 6 is an underside plan view, and Fig. 7 an edge view, of the loop holder
driving mechanism detached.
Figs. 8 and Figs. 9 shew respectively a plan and elevation of the parts in two
positions while making the chain stitch; and
Fig. 10 shows the relative positions of the loop holder and feed dog during the
withdrawal of the loop holder from its loop.
The invention may be applied to any shuttle sewing machine, but the machine
shown in the drawings, and to which the invention has been adapted, is that known
in the trade as the "German Singer" machine, in which the shuttle reciprocates
on a race placed longitudinally of the table of the machine.
This machine being well known, it is unnecessary to describe it, or to show
other than those parts to which my invention is applied.
To this end, A is the table of the machine, and B is the pillar carrying the
vertical needle bar, and operating mechanism, main shaft, and driving wheel (not
shewn). C is a vertical shaft, which receives rotary motion, through bevel gear,
from the main shaft, and communicates a reciprocating motion to the shuttle D through
a crank (and connecting rod C² (see Fig. 2).
The shuttle D reciprocates in the race D¹, which is provided with sliding covers in
the usual way. E is the loop holder (shewn detached at Figs. 3), which consists of
a flat plate having at its front end the prongs or fork E'. The loop holder may be
reciprocated from its rear end, near which is provided a socket E³ to receive a pin of
the driving mechanism to be hereafter explained. On one side, the plate may be
formed with a cam surface E, which, under certain conditions, bears against the
shoulder a on the table, under the influence of spring E, and it is also formed with a
projecting cam surface E' to be presently explained.
In the present instance, the loop holder works transversely of the table of the
machine, immediately below the throat plate, which holds it down in position. The
throat plate is secured by a screw b, which may pass through the slot in the loop
holder E. On the under side of this throat plate, is a bevelled shoulder d (see Figs. 5).
F is the feed dog, which is actuated in the usual manner, and is of the usual con-
struction, except that in the present case it has on the underside a rib or feather c, as
shown in Fig. 4 and indicated by dotted lines in Figs. 9.
This rib or feather e may not be necessary in all cases.
The driving mechanism for the loop holder is shewn in Figs. 6 and 7. On the
vertical shaft Cis mounted an excentric H, which works in a strap at one end of a
connecting rod H'. This rod is pivotted to a rocking arm H2, mounted loosely on an
axle J, and provided with a socket h, extending beyond the axle J, and forming a
catch. Mounted loosely on the same axle, by the side of the arm H2, is the bell
crank lever K, which carries at the end of the larger arm the pin f, which projects
through a slot in the table of the machine, and takes into the socket E³ of the loop
lolder E.
The other arm of this bell crank lever K is provided with bearings, in which
is mounted a locking pin or bolt g, around which is a coiled spring g', for giving the
locking pin motion in the direction of the axle J. This locking pin 9 is also provided
with a tongue ¹ and a milled head. In the edge of the table of the machine is a
notch, into which the tongue enters under certain conditions, as will be here-
after explained.
The locking ping, when the lever K is in the drawn position, will take into the
socket h, and lock the parts K and H2 together, so that the motion of the excentric-H
will be communicated to the part K, but when the lever K is moved to the dotted

page_text: position, and the pin g is drawn out, and the tongue h¹ is turned to enter the
notch in the table, the part H2 will be free to oscillate without the part K.
The above is a simple and convenient mechanism for throwing the loop holder
driving mechanism in and out of gear, according as it may be desired to employ a
lock stitch or a chain stitch, without the necessity for tilting the table of the machine,
and so disarranging the work.
Let it be supposed that it is desired to produce a chain stitch, the loop holder
driving mechanism will be locked, and the spool is removed from the shuttle, or
the shuttle thread may be cut off short, and secured by slipping it under the
tension spring of the shuttle. The operations necessary to produce the chain stitch
will be as follows:-The vertical needle having descended to its lowest position,
will, as it rises, throw out a loop in the usual manner, which the nose of the
advancing shuttle will enter. While the shuttle is passing through the loop, the
loop holder E is advanced, the spring Es causing its front end to swing over to
the right, looking from the front of the machine. The loop holder will thus advance
in a diagonal direction, and pass to the right hand side of the needle, the fork E
entering the loop (which is dragged to one side by the friction of the shuttle) just
before it leaves the heel of the shuttle, as will be seen in Figs. 8.
By this time, the end of the prongs of the fork E' will have passed across, and will
reach beyond the shuttle race, so that the loop cannot escape from the loop holder.
The needle all this time has been rising and the loop holder advancing, the
"take up" drawing up the slack thread as the shuttle passes out of the loop. So
soon as the point of the needle is above the work, the feed dog, now in its raised
position, commences to feed forward the work, and the loop holder advancing, the
end of the projecting cam surface E of the loop holder strikes the bevelled
shoulder d on the underside of the thread plate (see Fig. 5).
The loop holder, as it advances, is pushed by the bevilled shoulder d to one
side, ie, the left, the feed dog passing inside the projecting cam surface E' of the
loop holder when feeding.
As the loop holder is pushed over to the left, it carries with it, on its prongs,
the new loop, and brings the opened loop directly in the line of descent of the needle,
as will be seen at Figs. 9.
This lateral motion of the loop holder takes place at the time the feed dog is
raised, so that the projecting portion E of the loop holder can pass below the rib
or feather c on the underside of the feed dog.
The feed of the work having taken place, the feed dog is lowered while the loop
holder is in its advanced position, and the longitudinal rib of the feed dog drops down
inside the cam finger or surface E³.
This position of the parts is shown at Figs. 9. During the return motion of the
shuttle, the needle descends, and enters between the prongs of the loop holder and
through the open loop, the loop holder commencing to withdraw from the loop as
soon as the needle has passed sufficiently far to securely hold the loop. The back
motion of the loop holder takes place at right angles to the shuttle race, in consequence
of the cam finger E3 of the loop holder sliding on the outside of the longitudinal ribe of
the feed dog F (now in its lowered position, see Fig. 10), which will resist the tendency
of the spring to throw it over to the right, until the cam finger is withdrawn from the
feather, and the loop holder completes its back motion, being guided by the cam
surface E bearing against the shoulder a.
It will thus be seen that the loop holder has first to advance on one side of the needle,
namely, that on which the loop is formed, so that the fork may enter the loop and
hold it as it slips off the heel of the shuttle; next to move to one side to bring the
loop into position to receive the needle on its next descent, the needle then passing
between the prongs of the fork and through the loop kept open thereby; then to
withdraw from the loop on the line of its new position while the loop is held by
the needle, and while the new loop is being formed, to receive the nose of the
shuttle and finally to return to its former position preparatory to advancing to take
up the new loop.

page_text: For some constructions of shuttle sewing machines, the form of loop holder may
have to be slightly modified, but in every case it will be provided with a fork at its
front end, and it will be moved in the manner described in the preceding paragraph,
irrespective of the means for operating it.
When it is desired to use the lock stitch, the loop holder is brought into the
position shewn at Figs. 9, in which position it is retained by bringing the tongue h¹
of the locking ping into the dotted positions of Figs. 6 and 7. The bolt h having
been withdrawn, the lever or rocking arm H2 will now be free to vibrate without
communicating any motion to the bell crank K.
Then, by replacing the spool in the shuttle, or disengaging the shuttle thread from
the tension spring, the machine will be ready to produce the lock stitch.
It will thus be seen that the only change required to convert the lock stitch machine
to a chain stitch machine, and vice versa, will be the adjustment of the locking ping,
or other equivalent contrivance, in either of its two positions, and the severing or
otherwise of the shuttle thread.
The advantages of my invention are that the machine is self contained, and the
fixing of detachable appliances thereto to change the stitch obviated; also that
besides the locking and unlocking of the lovers K and H2, the only other change
necessary is the removing and replacing of the spool, a matter of almost hourly
occurrence with sewing machinists, and one that is well understood, or to cut off the
shuttle thread, as before described.
In some cases, the spool thread may be retained, when an effective embroidery stitch
will be produced, especially if the spool thread is of a different color.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. In a sewing machine, the combination with a shuttle suitably actuated, of a
reciprocating loop holder provided with a fork to receive the loop as it leaves the
shuttle, and hold it open for the next descent of the needle; means for horizontally
oscillating the loop holder during its reciprocation, and means for reciprocating the
loop holder in such a manner as to permit of the said oscillation, and capable
of being thrown in and out of action as required, substantially as and for the
purpose set forth.
a
2. A loop holder for shuttle sewing machines consisting of a flat plate having
fork at its front end, a cam extension, and a socket to receive a pin of the driving
mechanism, substantially as described.
3. In a shuttle sewing machine, the combination with a loop holder capable of
being reciprocated, and having a fork and a cam extension, of a throat plate formed on
its underside, with a bevilled shoulder d and a spring E³ secured to the table of the
machine, as and for the purposes set forth.
4. In a shuttle sewing machine, the combination of a reciprocating loop holder
formed with a fork, and a cam extension arranged parallel with the fork, of a feed
dog having on the underside a rib or feather which, at a suitable moment, enters
between the fork and the cam extension, to regulate the direction of return motion of
the loop holder, as described.
5. As a driving mechanism for the loop holder, the combination of the vertical rotary
shaft C, the excentric H on said shaft, the rocking arm H2 and bell-crank lever K,
and a pivot on which said arm and lever are separately pivoted, the said arm and lever
being connected, the one with the rod H' and the other with the loop-holder, and the
spring locking bolt g for locking the said arm and lever together, substantially as
herein described.
1
11
15L
1900
NEWTON & SON,
Agents for the Applicant.