Improvements in Sewing Machines.
Year: 1896

page_text: Date of Application, 8th Sept., 1896-Accepted, 21st Nov., 1896
COMPLETE SPECIFICATION.
[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, 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
lower or locking thread is carried by an oscillating shuttle, and it comprises
certain improvements in this class of sewing machines, as indicated in the claims
appended to this specification.
In the accompanying drawings,
Fig. 1 is a sectional side view of a sewing machine embodying my invention.
Fig. 2 is a view, partly in section, through the vertical portion of the
bracket arm.
Fig. 3 is a front end view of the head of the machine with the face plate
removed.
Fig. 4 is a front view of the face plate.
Fig. 5 is a top view of the thread controlling devices shown in side view in
Fig. 1.
Fig. 6 is a partial front end view of the machine showing the bed plate and parts
below the same.
Fig. 7 is a detail view of a portion of the shuttle operating mechanism.
Fig. 8 is a detail view of the shuttle and shuttle driver.
Fig. 9 is a detail view illustrating an auxiliary thread controlling device, and
Fig. 10 is a section of the same on line 2-2 of Fig. 9.
A denotes the bed plate of the machine, and B the bracket arm thereof.
Journalled in the upper portion of the bracket arm is the driving shaft C_provided
at its rear end, as usual, with the fly wheel D and with driving pulleys D². The
said driving shaft is provided at its forward end with a crank E connected by a
pitman E with the needle-bar E so that said needle bar receives its vertical
reciprocating movements from said crank. The driving shaft C is provided near
its rear end with a crank C3 connected by a pitman F to an arm F of a rock-
shaft G³ journalled beneath the work-plate of the machine, said arm F³ having a
pin g engaging a slot in the lever G pivoted at G, said lever having a second
slot g entered by a pin g' on the arm H at the rear end of the shuttle operating
rock-shaft H journalled centrally of the machine in suitable bangers beneath the
work-plate, and having at its forward end a driver H³ for operating the oscillating
shuttle H. The pitman F is preferably connected to the crank C' by a cap Fe
provided with a U-shaped wire spring attached to the pitman and the cap. This
construction permits the parts to be easily applied or assembled.
Secured to the driving shaft C is a cam C³ embraced by a feed-operating lever I
pivoted at its lower end, at b, to the bracket arm B, said lever being connected by
a link J to a second link J, the lower end of which is jointed to an arm K³ of the
feed operating rock-shaft K having at its forward end an arm K' to which the
feed-bar L, carrying the feed dog L³, is jointed, so that said feed bar receives its
horizontal movements from the said rock-shaft. The vertical movements of the.
Do37

page_text: said feed bar are imparted thereto by the rock-shaft G provided at its forward
end with the arm L' having a pin or roller stud received in a slot L' in the said
feed bar. The arm L' is clamped to the shaft G' so that it is axially adjustable
thereon to vary the height of the feed-dog L', as may be required.
The feed is regulated by means of a bell-crank lever consisting of two rigidly
connected arms J, J, the former of which is provided with the pin entering a
slot J in the link J', said link J' together with the link J constituting a toggle,
the position of the parts of which relative to the laterally vibrating feed-operating
lever I determines the extent of rocking movements imparted to the feed-operating
rock-shaft K; the said bell-crank feed operating lever having pivot stud or
bolts supported by a fixed lug or bracket Js inside of the vertical portion of the
bracket arm B. The arm J of the feed regulating bell-crank lever is threaded
and screwed into the hub of the arm J, and said arm J is provided with a block f
having inclined end faces for engagement with the faces of inclines B5, B6 formed.
on the bracket arm B, the latter being provided with a slotted segmental portion B'
outward through which the said arm J extends, and said arm is provided at its
outer end with a milled head B' by which it may be turned, and with a nut B.
between which and the segmental portion B' of the bracket arm is interposed a
friction spring S which serves to hold said arm in any position in which it may
be adjusted. By turning the screw arm Je by means of its milled head B the
block will be caused to travel in or out relative to the inclined portions B, Bo
of the bracket arm B; thereby varying the position of the feed regulating lever
consisting of the arms J, J, and thus changing the position of the toggle J, J.
relative to the feed operating lever I, so as to vary the vertical movements
of the link J, and thus regulate the movement of the feed operating rock-
shaft K.
In finishing off the ends of a seam it is frequently desirable to reverse the feed
so.as to sew a few stitches backward, and this can be done by simply raising the
arm Jo of the feed regulating lever so that the block f, which had formerly been
in contact with the incline B of the arm B, will be brought in contact with the
incline B' of the said arm, thus throwing the toggle over its centre, and causing
the feeding movements of the feed-bar to be reversed, the reverse feeding move-
ments being the same in length as the forward feeding movements in any position
of adjustment of the block f relative to the inclined stops B, B. The feed is
shortened by turning the screw arm Jo so as to move the block f inward and
thereby raise said arm toward a horizontal position, in which position the feed is
entirely suspended, the length of the feed being greatest when the said arm J® is
raised or lowered to its fullest extent, and being lesser as it is brought nearer to a
horizontal position, as will be readily understood by those familiar with feeding
mechanisms actuated by toggles operated on the principle of the feed mechanism
herein shown.
The driving shaft C is provided with a cam M which operates the take-up
lever T provided with an upward extension T having a thread-eye T' serving as
a pull-off, and to said extension or arm T2 is jointed, by a pin or bolt T, a push
rod U sliding in bearings afforded by posts U, U, formed on the bracket arm B;
the said push rod being held forward by the spring U³ interposed between the
post U and a collar or pin on said rod so as to hold the lower or shorter arm of
the bell-crank lever T in contact with the cam M; the said spring U³ serving
also to press the clamping tension discs a and a', mounted on said rod rearward of
said post U, into yielding contact with each other at proper times. Between the
post U and the tension discs a and a' is a washer V having thread guide slots,
and mounted on the post U is a check weight V beneath which the thread runs in
passing forward to the pull-off and take-up. V is a thread guide pin.
Attached to the arm B is the bracket 3 which supports the spool pins 4, 5. The
spool pin 4 has a tapered forward portion 4° fitting in a tapered hole formed in the
rear split end of the spool pin 5 so that said pins can be readily secured in
the socket at the upper end of the bracket 3 by inserting one into the other, and

page_text: ::
thus forcing the split sleeve at the rear end of the spool-pin 5 outward against the
inner wall of said socket, so that said pins are thus held in place by outward
pressure. The spool pin 5 is provided at its forward end with a disc d over which
the thread running from the spool held by said pin passes.
Co-operating with the pull-off and the intermittent tension I preferably employ
an auxiliary take-up or thread-controller consisting of a lever 8 pivoted to the
face plate, and provided with an inclined upper portion against which a pin. 7
carried by the needle bar engages at proper times, said lever being held in position
to be engaged by said pin by a spring 12. The face-plate is provided with a
thread guide 9, and below said thread-guide is a slot 10 in which the lower or
operating end of the auxiliary take-up or thread controller works; the lower arm
of the said take-up or controller being provided with an incline which is engaged
by a pin 11 carried by the presser-bar and which pin serves to limit the move-
ment of the said lever under the action of the spring 12. The height of the said
pin 11, is governed by the thickness of the work beneath .the presser foot so that
when the work is thick the said auxiliary take-up or controller 8 will be held in
such position that the incline at the upper end thereof will be engaged later in the
upward movement of the needle-bar than when the work is thin, and thus more
slack will be drawn up by said take-up or controller when the work is thin than
when it is thick.
Instead of using the auxiliary take-up or thread controlling mechanism just
described, and which is more clearly shown in Fig. 4, I might use the modified
form of thread controlling mechanism shown in Figs. 9 and 10 in which the
presser-bar is shown as being provided with an arm or cross-bar h carrying the
thread clamping spring e having an arm i to be engaged by inclines on the needle
bar E to force the said thread clamping spring e, between which and the
cross-bar h the thread.runs, away from said bar at proper times. As the vertical
position of the arm h attached to the presser-bar will be governed by the thickness
of the work beneath the presser-foot it is obvious that the thread pressed upon by
the spring e will be released earlier or later in the movement of the needle bar
according to the thickness of the work beneath the presser-foot, so that the
thread may always be left free or be slackened just as the needle is entering
the work.
In the operation of my machine the thread will run from one of the thread
spools to the thread-guide V, thence between the thread clamping discs a and a²
and through a slot in the thread-guide washer V and then beneath the check
weight V to the eye T' in the pull-off arm T2, and thence forward over the thread
guide at the top of the face plate; shown in Fig. 4, downward to the thread guide 9,
upward to the take-up lever T and thence downward through the eye at the lower
end of the auxiliary take-up or thread controller 8 to the needle. When the take-
up lever is performing the last part of its upward movement and the stitch has
been tightened the rod U will be forced backward by the upward extension T2 of
the take-up lever, releasing the clamping tension discs a and a' from contact, with
each other and thus permitting the take-up to draw thread from the thread spool,
while in the downward movement of the take-up lever the thread eye T¹ at the
upper end of the extension T of the take-up lever may also act as a pull-off to
draw thread from the thread spool and through the tension discs, if enough slack
thread has not already been supplied.
The shuttle operating mechanism herein described comprises two vibrating or
rocking parts, to wit, the arm F' of the rock-shaft G' and the slotted lever G, which
are interposed between the pitman F operated from the crank C' and the rock-
shaft H by which the shuttle is oscillated. From this construction it is apparent
that I am enabled to impart an oscillating movement in a large arc to the rocking
shuttle-operating shaft from a rotating crank on the driving shaft, and the shuttle
can therefore be operated to cause it to pass quickly through the loops of needle-
thread and there will remain ample time in the rotation of the driving shaft for the
operation of the feed and take-up. :

page_text: Having now particularly described and ascertained the nature of my 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 the driving shaft C arranged
centrally of the machine and provided with the crank C³ near its rear en and
a needle bar operatively connected to the forward end of said driving shaft, of the
-rock-shaft G provided with the arm F2, the pitman F connecting said crank with
said arm, the lever G provided with slots in its opposite sides, a pin g³ carried by..
said arm F and entering one of said slots, and a shuttle driving rock-shaft also
arranged centrally of the machine, and having an arm H provided with a
entering the other slot in the said lever G.
pin, as g¹,
2. In a sewing machine, the combination with the driving shaft C provided near
its rear end with a crank C, of the needle-bar operatively connected with the,
forward end of the said shaft, the feed lifting rock-shaft G having at its rear end
the arm F² provided with the pin 9³, and at its forward end the arm L provided
with a pin or roller stud, the pitman F connecting the said crank C' with the said
arm F, the lever G provided with the slots g and g², the latter entered by the said
pin 9, the shuttle driving rock-shaft H2 provided with the arm H, having a pin g
entering the said slot g, the feed bar I provided with a slot entered by the pin or
roller stud carried by the said arm L, and means for imparting backward and
forward movements to the said feed bar.
3. In a sewing machine, the combination with the driving shaft C provided with
the cam C³, of the feed operating lever I having a yoke embracing said cam, the
feed operating rock-shaft K provided at its rear end with an arm K³, the links J
and J connecting said feed operating lever with said arm K³, said link Ja being
provided with a slot, as J, and the feed regulating bell-crank lever consisting of
the arms J and Jo, the former provided with a pin or stud entering the said slot J
in the said link Ja, the feed bar L connected to the forward end of the said rock-
shaft K, to be moved back and forth thereby, and means for raising and lowering
the said feed-bar.
4. In a sewing machine, the combination with the driving shaft C provided with
the cam C, of the feed operating lever I having a yoke embracing said cam, the
feed operating rock-shaft K provided at its rear end with an arm K³, the links J
and J connecting said feed operating lever with said arm K³, said link J' being
provided with a slot, as J, and the feed regulating bell-crank lever consisting of
the arms J and J, the former provided with a pin or stud entering the shid slot J
in the said link J, the feed bar L connected to the forward end of the said rock-
shaft K, to be moved back and forth thereby, the feed lifting rock-shaft G' provided
with the arms F and L, the latter having a pin or roller stud engaging a slot in
the said feed-bar, to raise and lower the same, and means for operating the said
feed lifting rock-shaft from the said driving shaft.
5. In a sewing machine, the combination with the driving shaft thereof provided
with a cam, as C³, of the feed operating lever I having a yoke embracing said cam,
the feed operating rock-shaft K provided with the arms K³ and K³, the links J
and Ja connecting said feed operating lever with the said arm K³, the feed-bar L
connected with the said arm K2 to be moved back and forth thereby, the feed
regulating bell-crank lever consisting of the arms J and Jo, the former of which
is connected with the said link J and the latter of which is threaded, the bracket,
arm B provided with the inclines B and B and with the curved portion 'B',
the block having inclined faces to engage with the said inclines, and threaded
to embrace the threaded portion of the said arm Je, a nut, as B³, on the said
arm Jo, a friction spring interposed between the said nut and the said curved
portion B³, the feed lifting rock-shaft G operatively connected to the said
feed bar to raise and lower the same, and means for operating said feed lifting'
rock-shaft.
6. In a sewing machine, the combination with the driving shaft thereof, provided

page_text: with a cam, as M, and a stitch-forming mechanism operated from said driving
shaft, of the take-up lever T operated by said cam and provided with the
extension T, the push rod U connected with the said extension T to be operated
thereby, suitable bearings in which said push rod can slide, tension discs mounted on
said push rod, and a spring, on said push rod, for holding said discs in yielding
contact with each other.
7. In a sewing machine, the combination with the driving shaft thereof provided
with a cam, as M, and a stitch-forming mechanism operated from said driving shaft,
of the take-up lever T operated by said cam and provided with the extension T
having the pull-off thread eye T', the push rod U connected with the said extension T³
to be operated thereby, suitable bearings in which said push rod can slide, tension discs
mounted on said push rod, and a spring, on said push rod, for holding said discs in
yielding contact with each other.
8. In a sewing machine, the combination with a standard as 3 having a socket, of
a spool pin 5 fitting into said socket and detachable therefrom, said pin being bored
and split at one end, and an auxiliary spool pin 4 one end having a tapered portion,
as 4, entering the end of said detachable pin to expand it and fix it in said socket,
substantially as set forth.
-1000
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62 Saint Vincent Street, Glasgow, Agent for the Applicant.