IMPROVEMENTS IN THE STITCH PRODUCING MECHANISM OF LOCK-STITCH SEWING MACHINES
Year: 1884

page_text: COME LEIE DI MUIFICATION,
I EDWIN AMBROSE BRYDGES of the firm of Brydges & Co Engineers and Patent
Solicitors of 107 Königgrätzer Str. in the City of Berlin and German Empire do
hereby declare the nature of my Invention for IMPROVEMENTS IN THE STITCH
PRODUCING MECHANISM OF LOCK-STITCH SEWING MACHINES and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This Invention relates to improvements in lock stitch sewing machines without
shuttle or spool and whereby the threads are taken direct from the bobbins, and
consists of a most important improvement in sewing machines by means of which
it is possible to employ threads of unlimited length without being compelled to
wind the same onto the ordinary shuttle spools or bobbins and without any
detriment to the accurate operation of the machine and the production of a perfect
stitch. Any person having had experience with sewing machines will know how
severely it is felt that the ordinary spools or reels of cotton, thread, silk etc. as
generally known in commerce cannot be employed direct in sewing machines and
will also have experienced the trouble and loss of time consumed in winding the.
threads from the ordinary spools onto the shuttle, spool, or reel.
The difficulties are all avoided by employing the improved machine as described
in the following Specification.
Figure 1 is an elevation of the mechanism of the machine.
Figure 2 a view of the same seen from below.
Figure 3 a side view of the same.
Figure 4 is a vertical section on the line x x in Figure 2.
Figure 5 is a horizontal section on the line y y in Figure 4.
Figure 6 represents the thread holder and the lower opening in the cylinder C.
Figures 7 and 8 represent the combined loop openers and thread guides in
elevation and side view.
Figures 9 and 10 represent the bail or bow surrounding the spool or reel and the
moveable hooks for holding the said bail or bow in position.
Figures 11 and 12 represent in elevation and side view the gripping hook and
slide on an enlarged scale.
Figure 13 is a top view of the attachment ring with the moveable hook.
The mechanism of the machine consists of the following parts—
A bevil wheel L which gears into a second bevel wheel A is fixed to the main
shaft or spindle B

page_text: The wheel A is provided with a specially formed ring, is arranged around the cast
iron cylinder C and is kept in gear with the wheel D by means of the ring E which
said ring, is screwed to the lugs of the cylinder C by means of four or more or less
screws or bolts. The ring E is provided with four arms G in which four claws
catches or bell crank hooks F are inserted in order to hold the bowl or bail H and
the spool for the lower thread in a correct upright position.
The claws or catches act as bell crank levers the one arm of which is pressed
upwards by the spring M.or other equivalent device.
The lever arms which are operated on by the spring M and are provided with
small projections N (Figure 9 to 10) which come in contact with suitable projec-
tions N on the lower surface of the wheel A in such manner that the said arms are
periodically depressed and the catch or hooked ends freed from the bow or bail in
order to permit the upper thread to pass beneath the said bow or bail to the lower
thread spool.
The thread guides K with the three points 6 b' 63 (Fig. 4) which guide the upper
thread around the bow or bail to form the loop and also around the lower thread
are arranged in a corresponding position to the projections N¹.
An excenter L (Figure 1 and 2) transmits its excentrical movement to an angle
or bell crank lever and to the shaft or spindle O and is attached to the shaft B in
front of the wheel D. The shaft O is carried in suitable bearings in the cylinder C
and is provided with a suitable forked arm which reciprocates the gripper R in the
slot of the cylinder C.
.
The gripper R is shown on enlarged scale in Figure 11-the end or nose g of
which serves to depress the upper or needle thread so that the thread holder can
grip the same and the point or end of the thread guide can enter the loop and
enlarge the same. As the end or nose g of the gripper R descends the nose f is caused
to come in contact with a guide plate S which is screwed to the cylinder C so that
the gripper R is caused to turn on the pin e, make a downward movement and
transfer the thread to the thread holder Q. The thread guide K now comes into
operation, opens the loop by means of the point 6 and receives the same in the
guides 6 6 The gripper R now turns on the pin G¹ in order to allow the thread
guide to pass by the same and is then returned to its original position by means of
a spiral spring which is wound around the pin g'.
The thread guide is provided with a recess b in which a hook of the thread
holder is forced by means of the springs 8. The thread holder Q turns on the
pin and is returned or moved back by means of the thread guide K.
The thread holder O grips the loop and holds the one end of the same whilst the
other end of the loop runs through the stitch hole to the needle whereby the loop
is widened or enlarged by the continued rotation of the thread guide. The gripper Ŕ
is again raised by the arm P and a small spring on the pin or pivot e returns the
same to its original position ready to commence a fresh operation and draw a new
loop down. The spool containing the upper thread is arranged on a pin or pivot
provided with suitable springs. The drag is produced by the pressure of a screw.
on the end of the said pin or pivot.
The formation of the stitch or the binding of the two threads is carried out in
the following manner commencing at the point when the thread guide K comes into
action. A loose loop from the former stitch is present in the apparatus which as
described below is depressed by the gripper R which catches between the needle
and the thread leading to the loop.
As soon as the needle with the upper thread has passed its lowest point and
commences to ascend, the gripper R catches the loop formed by the needle and
upper thread passing through the stitch hole and transfers this fresh loop to the
thread holder Q, consequently the upper thread runs from the spool on the arm of
the machine through the stitch hole and the eye of the needle to the hook Q, from
here upwards over the lower thread of the material to be sewn. The projecting
point 6 of the thread guide now enters the loop and enlarges the same so that the
thread is readily laid over the points 6 b¹.

page_text: If the thread guide rotates further the loop will be widened still more, whereas
the old or former loop disappears. The loop which has now fallen from the bow or
bail is reduced in size by the enlargement of the next following loop so that the
thread guide first draws the last stitch tight and then fetches fresh thread from the
reel or spool.
The superior part of the upper thread is hereby guided over the lower thread
whilst the lower part of the same glides under the lower part of the bow or bail to
the lower thread and past the claws or catches F which are now released to permit
the free passage of the thread.
As soon as the thread guide has completed a semi-revolution the same ceases its
operation, the thread falls from the points or ends 6 61 of the same and is
simultaneously released from the hook or thread holder F. At this moment the
second thread guide which is arranged diametrically opposite to the first afore-
mentioned thread guide is ready to commence its operation, the stuff to be sewn
has been transported for the length of a stitch, the needle has made a new stitch
and the gripper depressed or forced down the loop so that the thread guide can
enter the said loop and thus form a new stitch.
By means of the construction and arrangement of the parts of the above described
machine the following advantages are obtained-
In consequence of the simple stroke of the excenter or cam the machine sews
doubly as quick or effects twice as many stitches as the machines known up to
the present time, as upwards of 1000 stitches can be made per minute-The
time consumed in winding the thread from the ordinary reels or spools onto the
shuttle spool is saved.
-
Inferior thread can be used for the lower thread which can even contain small
knots as it is not necessary to draw the said thread through fine holes or borings.
The rotary movement is perfectly equable so that the fine shocks experienced
with the present machines are avoided and the work is consequently more even
than can be the case with machines in which reciprocating shuttles are employed-
The machine can be employed to exceedingly great advantage for tambour and
other kinds of embroidery stitch, it sews the most accurate double stitch and
positively excludes all possibility of failing stitches and as the parts and the
consequent friction between the same are considerably reduced the power required
to operate the machine is considerably decreased.
The machine is exceedingly durable, sews the finest pearl stitch as well as the
longest stitch and sews leather and other thick material as well as the finest gauze
with like exactitude.
.
In case of damage to any part the same can be readily replaced by a reserve part.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed I declare that what
I claim and desire to secure by Letters Patent is :-
1. A double lock stitch sewing machine with rotary movement for the thread
guides and loop openers which serve to carry the upper thread direct around the
lower thread in order to produce the required locking of the stitch without the
employment of a shuttle or shuttle bobbin substantially as described in the foregoing
Specification and shown in the accompanying Drawings.
2. A double lock stitch sewing machine with rotary movement for the thread
guides and loop openers which serve to carry the upper thread direct around the
lower thread in order to produce the required locking of the stitch without the
employment of a shuttle or shuttle bobbin in combination with the gripper R and
the levers F substantially as described in the foregoing Specification and shown in
the accompanying Drawings.
3. The arrangement and construction of the parts of the said sewing machine in
such manner that the simple stroke of the needle forms a double lock or cross
stitch substantially as described in the foregoing Specification and shown in the
accompanying Drawings.
4. The bevil wheel D which is fixed to the main shaft B of the machine and

page_text: gears or meshes with the bevil wheel A at the lower part of the cylinder C
substantially as described in the foregoing Specification and shown in the
accompanying Drawings.
5. The bevil or mitre wheel A in combination with the ring E and the
cylinder C whereby the bevil wheel or ring A is in gear with the bevil or mitre
wheel D substantially as described in the foregoing Specification and shown in the
accompanying Drawings.
6: The ring E and its four arms G provided with four or more or less hooked
levers or claws F which latter are pressed upwards by means of the springs M so
as to hold the bail or bow H to the lower spool in correct position and which are
operated on by means of the projections Ñ¹ on the wheel or toothed ring A and
the small projections or studs N on the rear arms of the levers F in order to
momentarily release the said claws or hooks of the levers F from their gear with
the bail or bow H so as to permit the passage of the upper thread beneath the bow
or bail H to the lower spool substantially as described in the foregoing Specification
and shown in the accompanying Drawings.
7. The thread guides or loop openers K which are provided with three points
b 61 62 arranged in corresponding position to the projections N₁ and serve to
open or widen the loop and carry the same around the bow or bail H to the lower
spool or reel to transfer the loop. to the loop or thread holder Q and release the
said thread from the same by the next semi revolution of the ring A substantially
as described in the foregoing Specification and shown in the accompanying
Drawings.
8. The combination of the excenter L with the spindle O which said spindle is
carried in suitable bearings formed on the cylinder C and with the forked arm for
operating the gripper R which is arranged to slide in a slot in the cylinder C
substantially as described in the foregoing Specification and shown in the
accompanying Drawings.
+
9. The construction and arrangement of the gripper R for depressing the upper
or needle thread loop which, said loop is opened by the thread guide K and held
momentarily by the loop or thread holder Q whereby the said gripper turns on the
pivot g and the pivot e and is provided with a nose or projection f and a suitable
coiled spring wound around the pin or pivot g¹ substantially as described in the
foregoing Specification and shown in the accompanying Drawings.
10. The thread holder which turns on the pin or pivot r and is capable of
being moved back into a cavity b' in the cylinder C by means of the thread
guides K in order to allow the said thread guides to pass freely substantially
as described in the foregoing Specification and shown in the accompanying
.Drawings.
i 11. The general construction and arrangement of the parts of the said sewing
machine substantially as described in the foregoing Specification and shown in the
accompanying Drawings.
D. I TIL
1004
.