Improvements in Sewing Machines.
Year: 1897

page_text: [Communicated from abroad by THE SINGER MANUFACTURING COMPANY of New York,
in the United States of America, Sewing Machine Manufacturers.]
Improvements in Sewing Machines.
I, WILLIAM HARVEY INSLEE, Manager of The Singer Manufacturing Company,
Kilbowie, Dumbartonshire, do hereby declare the nature of this invention and in what
manner the same is to be performed, as communicated to me, to be particularly
described and ascertained in and by the following statement:-
My Invention relates to that class of lock-stitch sewing machines in which the
needle-thread is carried around the lower or locking thread by a shuttle having either
a reciprocating or a continuous rotary movement, the said lower or locking thread
being contained in a stationary case around which the loops of needle-thread are
carried by the shuttle; and my Invention has for its object to improve the class of
machines referred to, so that they will be adapted for higher speeds than at present.
All rotating or oscillating shuttle machines at present in use, and employing a
stationary bobbin or cop case containing the lower or locking thread, require a
relatively large loop of needle thread to encompass the mass of said lower or locking
thread wound on a bobbin or in the form of a cop housed in said case.
A large
bobbin or cop is, of course, desirable, to avoid stopping the machines frequently to
replace the empty bobbins with full ones, or to supply new cops, and there is therefore
a practical limit as to the size of the bobbin or cop case which must be employed;
and a reduction below a certain size would be objectionable. One of the objects of
my Invention. therefore is to provide such a construction and relative arrangement of
the bobbin-case and shuttle as will enable a smaller loop of needle-thread to encompass
a bobbin of a given size, held in a stationary bobbin-case, and which has therefore
required a much larger loop, thereby enabling me to employ a take-up with a shorter
and easier movement than heretofore, as well as avoiding drawing so much thread
back and forth through the eye of the needle.
Although certain features of my Invention may be advantageously employed in
machines in which the shuttles have continuous rotary movements, or in what are
known as "rotary" shuttle machines, my Invention is more particularly adapted for
machines in which the shuttles have reciprocating rotary movements and which are
known as "oscillating" shuttle machines. These oscillating shuttle machines as
heretofore constructed, and having stationary bobbin or cop cases, have required
oscillating shuttle movements of something more than half a circle to enable the loops
of needle thread to be carried around the bobbin or cop cases, the smallest oscillating
shuttle movements heretofore practicable for this purpose being from 206° to 210°.
For high speed machines of course it is much better to have the bobbin or cop cases*
stationary rather than movable with the shuttles, so as to avoid moving more weight.
than is absolutely necessary, in operating the rapidly moving shuttles. I have
discovered, however, that a stationary bobbin-case may have a pivotal connection with
the shuttle so as to be supported thereby, and still be arranged eccentric to the point
about which the shuttle oscillates, and that by thus arranging the bobbin-containing
case eccentric to the centre of oscillation of the shuttle the loops of needle thread

page_text: can be carried around the said case by a very much less movement of the shuttle than
heretofore; so that instead of requiring a shuttle movement of considerably more
than half a circle, as in machines at present in use, my improved oscillating shuttle
machine requires a shuttle movement of only about 158°, or considerably less than
half a circle, for practical use; and, in fact, an oscillating shuttle movement of as
little as 1520 is practically quite possible with a short-pointed shuttle.
This lessening of the oscillating movements of the shuttle enables me to increase
the speed of this class of lock-stitch machines nearly or quite one-third, by reason of
the following advantages secured. In the present "Singer" oscillating shuttle
machines the bell-crank rocker, through which notion is communicated from the
rotating main or needle-operating shaft journalled in the arm above the work-plate to
the shuttle-driving rock-shaft beneath the work-plate has, necessarily, in order that
said rocker may have the proper range of movement, a very short arm to which the
pitman extending from said arm to the crank on the driving shaft is connected.
With this short operating arın and the large movement which this rocker must
necessarily have, the joint between the arm and pitman, is at the two extremes of
the oscillating movements of the rocker, brought very close to the "dead point," or to
a centre line drawn from the centre of the crank above to the centre of oscillation of
the rocker, and thus causes a somewhat hard or harsh movement of the parts at these
periods of the operation of the machine. This hard or harsh movement detracts, in
a measure, from the capacity of the machine for high speeds. In my improved
machine, in which a much lesser movement is required for the rocker, the latter is
provided with a longer operating arm than heretofore, so that the pitinan connection
never comes very near the "dead point" referred to, and the longer operating arm
results in a very much easier movement of the rocker and of the shuttle-shaft which
it operates, and which shaft also has a lesser imovement than heretofore, thereby
adapting these parts for much higher speeds than in the old machines.
Owing to the lessened movements of the shuttle shaft and shuttle, as above.
explained, they can also be made somewhat slower, with relation to the movements of
the driving shaft, and this enables me to impart a lesser movement to the needle-bar,
by nearly one-quarter of an inch, than in the old inachines of this class and in which,
in order to get the proper timing of the needle and shuttle, to enable the former to
get out of the way of the latter, the needle necessarily descended lower than was
required merely to form the loops for the shuttle. In other words, I operate the
needle-bar of my improved machine from a shorter crank than is employed in the old
machines, and as the throw of the needle-bar is less than heretofore the friction
thereon is also less at a given rate of speed, thereby adapting this important element
of the machine for higher speeds. Furthermore the shortened throw of the needle-bar
permits of the use of a needle shorter, by three-sixteenths of an inch, than that
required by the old machines of the saine class, and this is greatly advantageous in
that the eye of the needle will be lifted above the work earlier in each stitch-forming
operation of the machine so that but very little thread will be drawn down, even by
a short-pointed shuttle, before the eye of the needle is above the work; and by using
a shuttle with a somewhat elongated point or beak the eye of the needle is easily
cleared from the upper surface of the work before the shuttle, in expanding the
needle-loop, begins to draw down thread.
In addition to the advantages in my improved oscillating shuttle machine of the
shortened shuttle and needle movements above described, resulting from the eccentric
arrangement of the stationary, bobbin-case or thread case, I, of course, secure the
advantages of the smaller loops of needle-thread required to encompass the lower or
locking thread and resulting in shorter and easier movements of the take-up, this
last-named feature of my Invention being applicable alike either to rotary or oscillating
shuttle machines; and as an easy take-up movement is one of the most difficult to
secure in lock-stitch machines, owing to the limited time in which it must be
performed, the advantages of this feature of my Invention will be fully apparent to
those skilled in the art to which it relates.
My improved machine comprises, in addition to the features above generally

page_text: outlined, a bobbin ejector with which is preferably connected a push rod which shoves
out the slide covering the opening in the work-plate through which access is had to
the shuttle; so that when an empty bobbin is thrown out by the ejector the slide will also
be removed for the convenient insertion of a full bobbin into the shuttle.
In the accompanying drawings, Fig. 1 is a front end view of an oscillating shuttle
machine embodying my Invention. Fig. 1a is a front view, on a larger scale than
Fig. 1 of the lower part of the machine, with the shuttle in a different position than
in Fig. 1. Fig. 2 is a vertical section through the arm and work-plate, showing the
connections between the upper and lower shafts. Fig. 3 is a bottom view of my
improved machine. Fig. 4 is a front side view of my improved shuttle, with its
eccentrically attached bobbin case, the shuttle being in its extreme backward operative
position relative to the bobbin case. Fig. 5 is a similar view with the shuttle in a
position far enough forward to have carried a loop of needle thread past the centre
of the bobbin-case. Fig. 6 is a front end view of the shuttle, showing also the
bobbin-case. Fig. 7 is a side view of the shuttle, with the bobbin-case detached.
Fig. 8 is a section of the shuttle on Line x-x of Fig. 7, and Figs. 9 and 10 are
detail views of the bobbin-case.
The machine herein illustrated is, in its general features, essentially the same as
the well-known "Singer" oscillating shuttle machine, in that it comprises the usual
bracket-arm A mounted on the work-plate B and in which former is journalled the
driving shaft C having at its forward end the crank c connected by a pitman c¹ with
the needle-bar D carrying an eye-pointed needle d, said shaft having near its rear
end a crank e² connected by a pitman 3 with the arm e of a bell-crank rocker the
lower arın el of which is slotted to embrace a slide f entered by a pin f¹ carried by an
arın fat the rear end of a shuttle-operating rock-shaft F journalled in bangers b
beneath the work-plate B and provided at its forward end with the shuttle driver f*
extending within the circular shuttle-race b attached to lugs 62 depending from said
work-plate. This machine also comprises what is known as the Singer
"link
take-up J.
Within the shuttle-race is arranged the shuttle G which consists of a segmental
shell comprising the inclined wings g, the rear one of which has a vertical sector or
continuation provided at the centre of motion of the shuttle with an opening g
for the reception of a small stud or boss h formed on the rear wall of the bobbin
case H, said stud or boss being preferably tapped for the reception of a screw h¹
which serves to connect said bobbin-case with the shuttle; said opening thus serving
as a pivoted support for said bobbin-case, and said boss and screw as a pivotal
connection of the said bobbin-case and shuttle. The beak g³ of the shuttle is formed
at the forward end of the peripheral flange which is preferably grooved for the
reception of a flange formed on the shuttle race. The pivotal connection of the
bobbin-case and shuttle is at a point which, as above stated, coincides with the axis of
movement of the shuttle, but which is eccentric to the bobbin-case which latter is, in
operation, held stationary by means of a prong h² which engages some fixed part of
the machine.
The shuttle is formed at its forward end, rearward of its beak, with somewhat
broad and blunt shoulders at g³, to accommodate the bobbin-case which is approached
by the periphery of the shuttle as the latter moves forward; and to prevent the
bobbin-thread from catching on the outer of said shoulders when the shuttle moveз
forward, the outer wing is provided with a hook g which, on the backward movement
of the shuttle, engages said bobbin-thread and draws it back slightly and thereby
prevents it from getting in front of said shoulder, said hook moving in an opening g'
between the prong h² and the bobbin-case.
I
The bobbin-case H is provided at its lower part with a flange h³ the inclined lower
wall of which serves as a cast-over guide, co-operating with the inclined forward
edge gs of the sector g¹, to direct the loops of needle-thread over or past the centre of
the bobbin-case when they are carried forward by the shuttle.
By pivotally supporting the bobbin-case, with its enclosed bobbin, on the shuttle at
a point concentric or coincident with the centre of motion of the shuttle operating

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shaft E, but with its pivotal point eccentric to the bobbin-case, it follows that as
the shuttle moves forward in passing into a loop of needle-thread, and in carrying
the same around the bobbin-case and bobbin, the latter are more and more closely
approached. by the shuttle until the cast-over position, shown in Fig. 5, is reached,
when the bobbin-case is comparatively close up to the periphery of the shuttle, so
that it can be encircled by a much smaller loop of needle thread than would
encompass it were it mounted concentrically with the axis of movement of the
shuttle, this difference in size of the needle-loop being about half an inch less for
the eccentrically mounted bobbin-case, as compared with a concentrically mounted
bobbin-case of the same size and thread capacity.
The curved periphery of the shuttle corresponds to the arc of a circle concentric
with the centre of movement of said shuttle, when the latter is in operation, and is at
all points equi-distant from the centre of the pivotal connection of the bobbin-case
and bobbin which pivotal connection coincides with the said centre of movement of
.the shuttle.
The joint, at h, forms a pivotal support of the bobbin-case on the shuttle, and said
bobbin-case is held stationary in the usual manner, while the shuttla oscillates about
it, by a prong h² of said bobbin-case, entering a notch or recess in the shuttle race.
The stationary bobbin-case is eccentrically supported on the shuttle above and to
the right (Fig. 1) of the centre of the shuttle driving rock-shaft F, or the centre of
.oscillation of the said shuttle, so that as the shell-shuttle moves forward and
comparatively near to the periphery thereof, and being also well to the right of the
centre of oscillation of the shuttle, the latter can carry the loops of needle-thread
far enough around said bobbin-case so that they will be in position to be drawn up by
the take-up without requiring the point of said shuttle to pass much, if any, below
a point which would be 45° below a horizontal line intersecting the centre of the
shuttle-operating shaft or the centre of the shuttle-race. In other words, owing
'to the eccentric arrangement of the stationary bobbin-case relative to the centre of
motion of the oscillating shuttle the latter is enabled to carry the loops of needle
'thread around the former with a very much smaller oscillating movement than
heretofore, this result being due to the fact that as the shuttle moves forward in
expanding and passing through a loop of needle-thread it travels toward the body
of the bobbin-case so that the latter becomes more and more completely housed
within the side walls of the shuttle shell, as the shuttle enlarges and passes into the
needle-loop and carries the latter around below the loop-dividing part of the bobbin-
case.
To provide for the convenient removal of the empty bobbins from the shuttle I
have furnished my improved machine with a bobbin ejector consisting of a sliding
rod i guided in the front hanger in which the shuttle shaft is journalled and
connected by a link to an operating lever I pivoted at i¹ to the under-side of the
work-plate B, said lever having at its outer or forward end a handle 2 extending
beyond the front side of the said work-plate. To remove the shuttle cover or slide 65
when an empty bobbin is ejected, for the convenient insertion of a full bobbin, I
provide a second slide rod guided at its forward part in one of the shuttle race
hangers and also connected, by a link , to the lever I, the front end of said rod ³
being herein shown as impinging against the holding spring b on the shuttle cover
or slide, so as to force the latter outward to an open position when the lever I is moved
forward to eject a bobbin. The lever I is retracted and is normally held in its
rearward or idle position by a coil-spring it connected to said lever and to the
under-side of the work-plate.
At the time when a bobbin is to be ejected from the bobbin-case the shuttle is
moved to its extreme backward position shown in Figs. 1 and 4, in which position it
is entirely clear of the path of movement of the bobbin-ejector i, the bobbin-case H
having at its rear wall an opening h' for the passage of the ejector i in forcing a
bobbin out of said bobbin-case. The sleeve or hub f by which the shuttle driver f
is attached to the shaft F is provided with a guard flange f" which prevents the bobbin'
ejector from being pushed-forward excepting when the shuttle is in its extreme

page_text: backward position at which time a recess or notch in said flange registers with said
ejector and permits of its passage. This guard flange prevents the accidental
operation of the ejector at an improper time, which might result in breakage.
In the operation of my machine the shuttle moves from its extreme backward
position shown in Fig. 1 (in which the needle is at its lowest point) to the forward
position shown in Fig. 1a, in which latter position the loop of needle thread will have
been carried far enough around the stationary eccentric bobbin-case so that it is now
in position to be easily drawn up by the take-up.
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 is :-
--
1. In a lock-stitch sewing machine, the combination with a needle and its
operating mechanism, of a shuttle operating shaft, a circular shuttle-race, a shuttle
running in said race, and a stationary bobbin or thread-case pivotally supported on
said shuttle at a point which is concentric with the centre of motion of the latter,
but eccentric to the said bobbin or thread-case.
2. In a lock-stitch sewing-machine, the combination with a needle and its operating
mechanism, of an oscillating or rocking shuttle-driving shaft, a shuttle operated by
said shaft and a stationary bobbin or thread-case pivotally supported on said shuttle
at a point which is concentric with the centre of motion of the latter, but which is
eccentric to the said bobbin or thread-case.
3. In a lock-stitch sewing machine, the combination with a needle and its operating
mechanism, of an oscillating shuttle, a bobbin or thread case pivotally and
eccentrically supported on said shuttle at a point concentric with the centre of motion
of the latter, and mechanism for oscillating said shuttle about said bobbin or thread-
case in a circular path of lesser extent than a half circle.
4. In a lock-stitch sewing machine, the combination with a shuttle race, a shuttle
running therein and a bobbin supported by said shuttle, of a bobbin ejector movable
longitudinally of the machine or transverse to said shuttle-race shuttle and bobbin, an
operating device or lever for said bobbin ejector, a shuttle cover or slide, and means,
operated by said device or lever, whereby when the latter is operated to eject a bobbin
said shuttle cover or slide will be opened to permit of the ready insertion of a full
bobbin.
5. In a lock-stitch sewing machine, the combination with a shuttle race, a shuttle
therein, an operating shaft for said shuttle and a bobbin ejector arranged outside of
and adjacent to said shaft and movable transversely to said shuttle-race and shuttle, of
a bobbin-case baving a rear wall provided with an opening for the passage of said
bobbin-ejector, and an operating device or lever for the latter: whereby the bobbin
can be thrown out by said ejector without removing the bobbin-case from the shuttle.
6. In a lock-stitch sewing machine, the combination with the shuttle-race, shuttle,
bobbin-case, bobbin, and shuttle cover or slide, of the bobbin ejector i, its spring-
retracted operating lever I to which said ejector is connected and the sliding rod is
also connected to said lever and serving to open said shuttle cover or slide when a
bobbin is ejected.
7. In a lock-stitch sewing machine, the combination with the shuttle-race, shuttle,
bobbin-case, bobbin and a normally stationary hobbin-ejector, of a guard movable
with the said shuttle when the latter is in operation and which prevents the said
ejector from being pushed forward to force out a bobbin excepting when said guard is
in some predetermined position relative to said normally stationary ejector, thereby
avoiding danger of breakage by accidental operation of the ejector at an improper
time.
8. The combination with a segmental shuttle, of a bobbin or thread case having a
pivotal connection therewith at a point which is concentric with the curved periphery
of said shuttle, but which is eccentric to the said bobbin-case.
9. The combination with a segmental shuttle, provided with inclined wings g, the
rear one of which has a sector or continuation g' in which, at the centre of motion of

page_text: the shuttle, or concentric with the curved periphery of the latter, is an opening 9², of
the bobbin-case having an eccentric boss or stud h journalled in said opening and thus
forming an eccentric pivotal connection of said bobbin-case with the centre of
movement of the shuttle.
10. The combination with a segmental shuttle provided on its front side with a
hook, as g, of a bobbin-case having a pivotal connection with said shuttle at a point
which is concentric with the curved periphery of said shuttle, but which is eccentric
to said bobbin-case, the latter being provided on its forward side with a prong, as h²,
between which and said bobbin-case there is an opening, as g7, in which said hook
moves to draw the bobbin thread back and prevent it from getting in front of the
forward shoulders of the shuttle.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62 Saint Vincent Street, Glasgow, Agent for the Applicant.