Improvements in Sewing Machines.
Year: 1894

page_text: Date of Application, 26th July, 1894-Accepted, 18th May, 1905
[Communicated from abroad by THE SINGER MANUFACTURING Co., of New York,
in the United States of America, Sewing Machine Manufacturers.]
Improvements in Sewing Machines.
I, ALEXANDER ANDERSON, Manager of The Singer Manufacturing Company's
Works, Kilbowie, Dumbartonshire, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My invention has for its object to improve that class of lock-stitch sewing
machines in which the lower or locking thread is supplied from a bobbin sustained
by bobbin case or holder which is in turn supported in the cavity of a rotating or
oscillating hook. In machines of the class referred to the bobbin case or holder
has heretofore been placed loosely within the hook so as to rest by gravity on the
lower inner side of the hook, and thus have a peripheral contact therewith. This
peripheral contact of the bobbin case with the inside of the hook induces so much
friction between the hook and bobbin case that the latter, partaking more or less of
the movements of the hook, frequently rotates in such a manner as to twist or
untwist the bobbin thread, even with an oscillating hook; as at high speeds the
bobbin case, carrying the bobbin with it, sometimes starts to rotate continuously,
thus causing this twisting or untwisting of the thread.
While it is true that this objectionable movement of the bobbin case might be
avoided by holding the bobbin case stationary while the hook is in motion, this
manner of obviating the difficulty would be objectionable with a bobbin case having
a peripheral contact with the hook for the reason that at high rates of speed and
running the parts dry there would be too much friction between the bobbin case
and hook, and if the interior of the hook be oiled to avoid this friction the needle
thread, which passes around the bobbin case within the hook, will be greased and
thereby soiled.
My invention has for its object to obviate the difficulty referred to by supporting
the bobbin case and its contained bobbin within the hook in such a manner that there
will be no peripheral contact between the bobbin case proper and the hook, thereby
permitting the bobbin case to he held stationary while the hook is in motion,
without objectionable friction. This object 1-accomplish by interposing between
the bobbin case proper and the hook a second or supplemental bobbin case of
cylindrical form which is loosely fitted within the hook and which is furnished with
a central pin or support which engages a central sleeve or support on the bobbin
case proper. Thus the contact between the bobbin case proper and its support,
instead of being at the periphery of the bobbin case, as heretofore, is at or near the
centre thereof, so that the friction between the bobbin case and its support is
reduced to a minimum and is so slight that the objection heretofore existing to
holding the bobbin case stationary is obviated. The auxiliary or supplemental bobbin
case which is loosely interposed between the bobbin case proper and the inner wall
of the hook, by being made in cylindrical form, or without exterior projection, has
no positive connection with the hook, but only moves by frictional contact there-
with, so that there will be no noise occasioned by positive contact of metallic parts
which would be objectionable, particularly with an oscillating hook, the movements
of which are being constantly reversed; and while there is no appreciable friction
between the auxiliary bobbin case and the hook, owing to the fact that both are
practically moving together, there is still a certain slight "slip" between the parts

page_text: incidental to the avoidance of the positive metallic contacts above referred to, and
which "slip" results from the fact that the auxiliary cylindrical bobbin case is free
to move within and independently of the hook.
Another object of my invention is to provide means for positively controlling the
loops of needle thread after they have been passed around beneath the bobbin case so
that as they are being drawn up by the take-up they will be held in contact with the
beak portion of the hook until they are well shortened as they are being drawn up
towards the work plate, and thus a difficulty sometimes occurring in oscillating hook
machines, and resulting from the kinking of the comparatively long and loosely-
held loops of needle thread when the machines are running at high speeds, is
avoided.
With the employment of the cylindrical bobbin case hereinbefore referred to the
loop carrying portion of the said hook is necessarily extended forward of the point
or beak of the book, and said loop carrying portion of the hook is thus in the way
of so early a discharge of the loops, on the backward movement of the hook, as is
desirable.
By a modification of my invention I avoid the objection mentioned by providing
the supplemental or outer bobbin case with a peripheral loop-carrying projection
which is preferably of pyramidal form and the point of which is loosely housed
within a groove formed in the under or inner side of the loop-seizing beak portion
of the hook. This loop carrying device being thus formed on the outer bobbin
case instead of on the hook, as in the other form of my invention, the loops of
needle thread will pass around or outside thereof, instead of inside thereof, as
before, and I thus provide a construction which enables, the said loops to be
discharged or drawn up from the hook earlier in the backward movements of the
latter than in the former construction, so that more time in the rotation of the
needle-bar operating driving shaft is secured for the operation of the take-up and
feed, and thus a better timing of the different parts of the machine may be
effected.
The pyramidal projection moves with the oscillating hook and is in such position
as to extend from the bobbin-case upward towards the work plate at the time when
a loop of needle thread has been carried around below the centre of the bobbin case
and is being drawn up by the take-up to tighten the stitch, the said projection
(between which and the beak of the hook the loop of needle thread must pass)
serving to hold the upwardly moving loop in contact with the beak of the hook until
the loop is so short and is so close to the underside of the work plate that kinking
of the thread of the said loop is wholly avoided.
A further object of my present invention is to provide an oscillating hook, with
a beak shank of such construction, that, when co-operating with a threaded needle
operated from a regularly moving crank pin, no thread will be drawn down through
the eye of the said needle while the latter is moving upward through the work, thus
adapting the hook for use in machines for sewing leather and other firm or com-
paratively hard material and having regular needle bar movements; to provide an
oscillating hook which will positively hold and control the loops of needle thread
until they are so well shortened, in being drawn up, that they cannot twist or kink;
and also to provide an oscillating hook with a guard to hold the bobbin thread out
of the way of the beak of the hook and with a needle guard, so that while the needle
may be so set as to travel close to the path of the point or beak of the hook there
will be no danger of breaking the said needle.
In carrying this part of my invention into effect the body of the oscillating hook
is provided with a long beak-shank which first increases and then diminishes in
cross section from the point or beak rearwardly, being preferably largest at or near
its middle portion, so that when the needle has descended and a loop of needle
thread has been caught by said point or beak said loop will be immediately so
enlarged by the forwardly moving beak-shank, before the eye of the regularly
operated, upwardly-moving needle reaches the under side of the work, that while
the eye of said needle is moving upward through the work the slack rendered or

page_text: journalled on said sleeve c¹ within the case c. The auxiliary bobbin case b is placed
in the cavity of the hook a with its open end outward or towards the front of the
hook, while the bobbin case proper c is placed within the hook with its open end
towards the back of the latter. The said bobbin case c is furnished with a suitable
tension device, as the spring on the periphery thereof, the lower thread being
drawn upward and through a delivery hole or throat ca formed in the said bobbin
case, the thread passing from said hole outward to the front edge of the bobbin
case beneath said tension spring which is provided at its front edge with a guiding
notch which holds the thread in place at the point of delivery.
It will thus be seen that the bobbin case proper c is supported at its centre on
the pin so that it has no peripheral contact with the interior of the book, and it
is thus adapted to be held stationary while the hook is in motion without involving
such an amount of friction as is seriously detrimental. To hold the said bobbin
case stationary and to keep it in the hook a I have, as herein shown, provided a
pivoted latch or finger e sustained by a bracket depending from the work-plate h
of the machine, the upper end of said latch or finger pressing lightly against
the said bobbin case c at the cavity or recess c³ formed in said bobbin case, and the
said latch being, as herein shown, held in place by a suitable plate spring g.
The outer or auxiliary bobbin case b which is interposed between the bobbin
case proper c, and the interior of the hook a, being of cylindrical form or without
exterior projection or projections, is free to be moved axially independently of the
said hook, so that as the hook is rotated or oscillated, while said bobbin case will
move mainly therewith, owing to its weight and its peripheral frictional contact
with the hook, said bobbin case, having no positive connection with the hook, will
be free to 66
slip" slightly on. the latter, and thus with an oscillating hook
objectionable blows, such as would result from positive metallic contacts, are
avoided, while little or no friction is engendered between the auxiliary bobbin case
and hook, the movements of the two being nearly co-extensive.
It will also be clear that as the bobbin case proper is supported at or near its
centre, instead of at its periphery, as heretofore in the class of machines to which
my invention relates, there will be but little friction thereon. Thus by my new
combination of a hook a hobbin case proper and an auxiliary cylindrical bobbin
case or bobbin support interposed between the said hook and bobbin case proper
1 am enabled to hold the latter bobbin case stationary without objectionable
friction.
By the term "cylindrical " as used in the claims of this Specification in
conection with the auxiliary bobbin case I wish it to be understood as meaning a
bobbin case which has no peripheral or other projection or projections such as
would give it a positive connection with the hook which supports it.
The hook a is provided at the front edge of its outwardly curved heel a² with a
notch or shoulder a' so arranged as to engage the bobbin thread (delivered from the
front edge of the bobbin) when the hook is at its extreme backward position as
shown in Figure 5. At the moment when the hook is in this backward position
and is about to commence its forward movement the take-up has tightened the
stitch so that the bobbin thread is now drawn taut, and thus as the shoulder a
engages the bobbin thread a sufficient amount thereof for the next stitch is drawn
from the bobbin.
In the operation of my invention the loops of needle thread caught by the point
or beak a¹ of the hok a are, by the movements of said hook, carried around the
outer or auxiliary bobbin case b to about the position shown in Fig. 4 when the said
loops are drawn up by the said take-up and out of the mouth of the hook after the
latter has moved around to about the position shown in Fig. 5, as is common with
machines of the class to which my invention relates.
Referring to Figures 7 to 14 of the drawings, A, denotes a part of the hook
shait which may be oscillated in any suitable manner and a is the hook attached
thereto.
Fitting loosely within the cavity of the hook a is the supplemental or outer

page_text: hobbin case 6 which is provided with a peripheral projection 6' preferably of
pyramidal form, or approximately so, the point of said projection extending into a
groove at formed in the under or inner side of the loop seizing beak-portion of
the said hook, the said point of said projection being preferably inclined forward
slightly as shown in the drawings. The said point serves as a stop for the loops
of needle thread, and the front side of said projection serves as a loop carrier
to carry the loops of needle thread forward and around the bobbin-case, as shown
more clearly in Figs. 11 and 12, so that on the backward movement of the hook,
when the latter has reached a position a little past that shown by Fig. 13 the loop
may be drawn out of the mouth of the hook somewhat carlier in the movement of
the latter than is possible with the construction hereinbefore referred.to.
As the loop of needle thread is being drawn upward, after having been passed
round, beneath the bobbin-case b, the pyramidal projection 6' on the said bobbin
case holds said loop in contact with the inner side of the beak of the hook a, so
that the loop is thus positively held and controlled, until it is so well shortened
that said loop cannot twist and kink, the point of the said projection b¹ extending
within the grove or recess at, formed in the inner or underside of the beak of the
hook, assisting in this operation of controlling the thread in that it serves as a slight
check on the loop as the latter is drawn upward, said point momentarily holding
the loop in contact with the beak of the hook as said loop passes upward; and as
the loop will thus be very short, when it has finally escaped from the hook, all
twisting or kinking of the loop, which might otherwise occur at high rates of
speed, is entirely avoided.
To retain the outer or supplemental bobbin case within the hook I prefer to
attach to the heel of the latter a holder c which extends partly over the mouth a³
and the end of which is rounded, as shown, and by which, and a slight rounded
projection a formed on the inner side of the hook, the weight of the bobbin case
and bobbin is sustained when the parts assume the positions shown by Figure 12,
so that the point of the projection 6' on the supplemental or outer bobbin case need
never touch the bottom of the groove in the hook in which it is housed.
When the outer bobbin case b is to be removed from the hook a the holder c is
taken off, and the point of the projection 61 may then be turned forward slightly
to disengage it from the groove within the side walls of which it is housed, thus
leaving the said bobbin case free to be removed from the hook.
The outer bobbin case is provided with a central support or pin & wmcn engagés
a central support or sleeve d', formed on the inner bobbin case, or bobbin case
proper d, the latter enclosing the disc bobbin e and being provided with the tension
spring d. The inner bobbin-case is held stationary in any suitable manner, as by
a latch supported by a hanger g depending from the work plate h of the machine.
By thus sustaining the stationary inner bobbin case by a central support on
the moving outer bobbin case the friction between the parts is reduced to a
minimum.
Referring to Figures 15 to 20 of the drawings A, denotes a part of the hook
shaft to which is attached the hook a having a cavity in which is supported an
outer or supplemental bobbin case b having a central pin or support b' engaging a
central sleeve or support cl on an inner bobbin case, or bobbin case proper c, which
encloses the bobbin d. The bobbin case c is held stationary by any suitable device,
as by a latch or finger e. The hook a is provided with a loop seizing point or
beak a which is carried by a long beak shank a² which is enlarged rearwardly
from the beak a' preferably to or near its middle portion where it is largest in cross
section, being preferably swelled or enlarged both inwardly and laterally as shown;
said beak shank tapering or diminishing in cross section rearwardly from its
enlarged portion to its neck portion as where it joins the body of the hook.
said hook body a is provided at its heel portion with a broad tail-piece a* which
extends laterally on both sides of the beak a¹ of the hook, said tail-piece being
beneath or within said beak so as to be overlapped, radially, by the latter.
Between said heel or tail-piece a and said point or beak a¹ is an opening or
The

page_text: mouth a into which the loops of needle thread are entered and out of which they
are drawn by the take-up after having been passed around the bobbin cases and
the locking thread supplied from the bobbin contained therein; the said tail-piece,
-extending beneath or being overlapped, radially, by the said beak a¹, serving to
-contract said opening or mouth and thus guard the same from the too early escape
of the loops of needle thread. The said tail-piece is broad enough so that the front
face a¹º of its rear end is laterally to the left or on the front side of the beak a',
and thus serves to hold the hobbin-thread laterally out of the way of the said beak
when the latter is advancing to take a loop of needle thread.
Rearward of the slot as formed between the rearwardly tapering rear portion of
the beak shank and the body portion of the hook is the thread carrying or loop
spreading part a of the hook, the front face of said part serving as a stop for the
loops of needle thread into which the beak shank has fully entered, as in Figure 18,
so that as the hook moves forward to the position shown in Figure 19 the loop in
engagement with said face will be enlarged and carried around beneath the bobbin
cases in position to be drawn up on the left or rear side of the bobbin cases, and
thus when the hook is reversed to bring its mouth upward the loop may escape
from said mouth and be tightened into the work.
The broad tail-piece a is provided with a needle slot at one side of which is a
flange projecting radially from the periphery of said tail-piece and having a front
vertical face as which is in line, or approximately so, with the point or beak a' of
the hook a so as to serve as a needle guard to prevent a needle, which is bent
towards, or set to reciprocate in a line too near the path of said point or beak,
from being damaged or broken by being struck by the latter; said face or needle
guard a moving in front of the said point or beak when the latter advances to
take a loop of thread from the needle. The tail-piece a is provided with a slight
lateral projection to form a shoulder a' which serves, when the hook is in its
-extreme backward position, to engage the bobbin thread to draw off slack enough
for the next succeeding stitch, as described with reference to Figures 1 to 6 of the
drawings.
Figure 17 represents the relative positions of the hook and needle as the latter
is descending and is adjacent or contiguous to the needle guard or face aº.
Figure 18 represents the relative positions of the hook and needle when the beak
shank has been fully entered into the loop of needle thread and the eye of the
needle has risen above the work, and the hook then advances from the position
shown in Figure 18 to the position shown in Figure 19 to carry the loop around
beneath the bobbin cases; Figure 19 representing the hook in its extreme forward
position and ready to commence its reverse movement. In the position shown in
Figure 20 the hook in its reverse or backward movement has returned far enough
to permit the loop of needle thread to have been so well shortened or drawn up,
while still in contact with the beak shank and beak, that when dropped from said
beak, as the hook continues its backward movement, said loop will be so small that
it will not be liable to twist and kink, and all difficulty from this source of trouble
will be avoided.
It will thus be seen that with my improved hook I avoid the difficulty incidental
either to drawing the thread through the eye of the needle or to moving the needle
upward on the thread when the needle-eye is in the work; and I am enabled to
positively hold and control the loops of needle thread until they are so well
shortened and drawn up that danger of kinking of the said loops is avoided; and
that I also provide the oscillating hook with an efficient bobbin-thread guard and
.needle guard.
Having now particularly described the nature of the said invention and in what
manner the same is to be performed (as communicated to me) I declare that what
I claim is:-
1. In a sewing machine, the combination with a hook having a central cavity and
Joon-seizing noint o book of on
villal Lathin
Lagine ite

page_text: extreme contour in a true circle and loosely fitting in said cavity so as to be enclosed
and supported by said hook, said auxiliary bobbin-case having a central support, a
bobbin-case proper fitting loosely within and enclosed by said auxiliary bobbin-case
and also having a central support engaging the central support of the said auxiliary
bobbin-case, and means for holding said bobbin-case proper stationary when the
said hook is in motion.
2. The combination with the hook a having a central civity, of the cylindrical
auxiliary bobbin case having its extreme contour in a true circle and loosely
fitting in said cavity, and provided with the central pin, the bobbin-case proper e
having the central sleeve c¹ loosely fitting on said pin, and the finger or latch e for
holding said bobbin-case e stationary when the said hook is in motion.
3. In a sewing machine, the combination with an oscillating hook having between
its point and its heel an opening or mouth for delivering the loops of needle thread.
and having at its heel on its front side a notch or shoulder, of a bobbin-case within
said hook having a thread delivery at its front edge to hold the thread in the path
of movement of said notch or shoulder, whereby the latter, when the hook is at its
extreme backward position, is adapted to draw sufficient thread from the bobbin for
the next stitch.
4. In a sewing machine, the combination with a hook having a central cavity
and a loop seizing point or beak, of an auxiliary cylindrical bobbin case having its
extreme contour in a true circle, and fitting loosely in said cavity so as to be
enclosed and supported by said hook, said auxiliary bobbin case having a central
support and being placed in said cavity with its open end outward, or toward the
front of the hook, the rear end of said auxiliary bobbin case being closed, a bobbin case
proper fitting loosely within and being enclosed by the said auxiliary bobbin case,
and also having a central support engaging the central support of the said auxiliary
bobbin case, the said bobbin case proper having a closed outer end or head and
being placed within the said hook with its open end toward the back of the latter,
and means for holding the said bobbin case proper stationary when the said hook
is in motion.
5. In a sewing machine, the combination with a hook having a central cavity
and a loop-seizing beak portion provided with a groove or recess on its under side,
said groove or recess having opposite walls at the sides of the under portion of said
beak, of an outer or supplemental bobbin case having a central support and having
also a peripheral projection the point of which is housed within the said opposite
side walls of said groove or recess, and an inner bobbin case, or bobbin case
proper, having a central support engaging the said central support of the outer
bobbin case.
6. In a sewing machine, the combination with a hook having a central cavity, a
loop seizing beak portion provided with a groove or recess on its under or inner
side, a heel, and a mouth between said heel and beak, said groove or recess having
opposite walls at the sides of the under portion of said beak, of an outer or supple-
mental bobbin case having a central support and having also a peripheral projection
the point of which is housed within the said opposite side walls of said groove or
recess, an inner bobbin case, or bobbin case proper, having a central support
engaging the said central support of the said outer bobbin case, and a holder for
the said outer bobbin case, said holder being carried by said hook and extending
partly over said mouth.
7. In a sewing machine, the combination with a hook having a central cavity, a
loop seizing beak portion provided with a groove on its under or inner side, a heel,
and a mouth between said heel and beak, of an outer or supplemental bobbin case
having a central support and having also a peripheral projection the point of which
is housed within the side walls of said groove, an inner bobbin case, or bobbin case
proper, having a central support engaging the central support of the said outer
bobbin case, and a holder for the said outer bobbin case extending partly over said
mouth, said holder being removably secured to the body of said hook.
8. An oscillating hook for sewing machines provided with a loop seizing point or

page_text: beak and with a broad tail piece which extends laterally on both sides of the said
P₁ int or beak, and which is beneath or inside of, and is thus over-lapped, radially,
by the said point or beak, said hook having between said beak an tail-piece an
opening or mouth into which the loops of needle thread are entered and out of
which they are withdrawn, and which opening or mouth is guarded by said
tail-piece.
9. An oscillating hook for sewing machines provided with a loop-seizing point or
beak and with a broad tail-piece which extends laterally on both sides of the said
point or beak and which is beneath or inside of, and is thus over-lapped, radially,
by the said point or beak, said hook having between said beak and tail-piece an
opening or mouth into which the loops of needle thread are entered and out of
which they are withdrawn, and which opening or mouth is guarded by said tail-
piece, and said tail-piece having a face which is in front, laterally, of the said
point or beak so as to serve as a guard for the bobbin thread to hold the latter
aside when the said point or beak is advancing to take a loop of needle thread, and
said tail-piece having also a needle slot at one side of which is a radially projecting
flange one face of which is in line, or approximately so, with said point or beak, to
serve as a needle guard.
10. An oscillating hook for sewing machines provided with a loop-seizing point
or beak and with a broad heel portion or tail-piece having a needle slot at one side
of which latter is a flange projecting radially from said tail-piece and one face of
which flange is in line, or approximately so, with the said point or beak, to serve as
a needle guard, said hook having between said point or beak and said tail-piece an
opening or mouth into which the loops of needle thread are entered and out of
which they are withdrawn.
11. An oscillating hook for sewing machines provided with a loop-seizing point
or beak ard with a long beak shank which is swelled or enlarged and then
diminished in cross-section from said point or beak rearwardly, said hook being also
provided with a broad heel portion or tail-piece which extends laterally on both
sides of the said point or beak and which is beneath or inside of the said point or
beak, so as to be overlapped, radially, by the latter.
12. An oscillating hook for sewing machines provided with a loop seizing point
or beak and with a long beak-shank which is swelled or enlarged and then
diminished in cross-section from said point or beak, rearwardly, said hook being
also provided with a broad heel portion or tail-piece which extends laterally on
both sides of the said point or beak and which is beneath or inside of the said
point or beak, so as to be overlapped, radially, by the latter, and the said tail-piece
having a necale slot at one side of which is a flange projecting radially from said
tail-piece and one face of which flange is in line, or approximately so, with the
said point or beak, to serve as a needle-guard.
13. An oscillating hook for sewing machines provided with a loop seizing point
or beak a¹ and with a long beak shank a' which is swelled or enlarged and then
diminished in cross-section from said point or beak rearwardly, said hook having a
loop-spreading part a' inside, radially, of the said beak shank and between
which loop-spreading part a' and the said shank is a slot aº, the said hook having
also a broad tail-piece at which extends, laterally, on both sides of the said point
or beak and which is beneath or inside of said point or beak so as to be overlapped,
radially, by the latter.
14. An oscillating hook for sewing machines provided with a loop seizing point
or beak a¹ and with a long beak shank a² which is swelled or enlarged and then
diminished in cross-section from said point or beak rearwardly, said hook having a
loop-spreading part a inside, radially, of the said beak shank and between which
loop-spreading part a' and the said shank is a slot a³, the said hook having also a
broad tail-piece at which extends, laterally, on both sides of the said point or beak
and which is beneath or inside of said point or beak so as to be overlapped, radially,
by the latter, and the said tail-piece having a needle slot at one side of which is a
flange projecting radially from said tail-piece and the outer face a of which

page_text: flange is in line, or approximately so, with the said point or beak, to serve as a
needle guard.
15. An oscillating hook for sewing machines provided with a loop seizing point
or beak a¹ and with a long beak shank a² which is swelled or enlarged and then
diminished in cross-section from said point or beak rearwardly, said hook having
a loop-spreading part a' inside, radially, of the said beak shank and between which
loop-spreading part a' and the said shank is a slot aº, the said hook having also a
broad tail-piece at which extends, laterally, on both sides of the said point or beak
and which is beneath or inside of said point or beak so as to be overlapped,
radially, by the latter, and the said tail-piece having a needle slot at one side of
which is a flange projecting radially from said tail-piece and the outer face a*
of which flange is in line, or approximately so, with the said point or beak, to serve
as a needle guard, the said tail-piece having also a face at which is laterally in
front of the said point or beak and which is provided with a shoulder a³ to serve
as a pull-off for the bobbin thread.
Dated this 25th day of July 1894.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.