Improvements in Sewing Machine Shuttles.
Year: 1899

page_text: Date of Application, 17th May, 1899-Accepted, 1st July, 1899
[Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of New
York, United States of America, Sewing Machine Manufacturers.]
Improvements in Sewing Machine Shuttles.
I, JOHN KING MACDONALD, Manager of The Singer Manufacturing Company,
Kilbowie, Dumbartonshire, do hereby declare the nature of my said invention,
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 shuttles for that class of sewing machines in which,
to avoid moving more weight than is necessary with the circularly moving,
oscillating or rotating shuttles, the bobbin or cop cases are held stationary
while the shuttles move about them in expanding and carrying the loops of
needle thread around the lower or locking thread. The present invention has
for its object to provide a stationary bobbin-case of such construction that while
it will contain a bobbin capable of holding a relatively large amount of thread
said bobbin-case is so arranged relative to the shuttle that it may be encom-
passed by comparatively small loops of needle thread, this construction and
arrangement being such that said loops may be cast over the bobbin-case by a
lesser circular movement of the shuttle than is required in carrying loops of
needle thread around the stationary bobbin-cases of "central-bobbin
or shuttles equipped with stationary bobbin-cases placed eccentric with the axes
of movement of said shuttles. This object is effected by providing a "barrel" or
shuttles,
cylindrical bobbin-case adapted to contain
said barrel bobbin-case being held stationary in the usual
a long or cylindrical bobbin,
being provided with a
the shuttle race, and being supported on a pin on the shuttle arranged concen-
prong or finger which engages some
ric with the axis of movement of the latter, or approximately so, but which
part of
in passes through the bobbin-case at one side of the bobbin-chamber of the
atter. Another object of the invention is to provide the shuttle with an intermit-
ingly-acting or "automatic" tension device which will relax the tension of
he shuttle thread when the work is being advanced by the feed so that said
read may at such times draw freely from the bobbin or cop in the shuttle.
his result is preferably effected by providing the bobbin-case supporting-pin
the shuttle with a small cam or eccentric which at a certain predetermined
eriod in the movement of the shuttle will slightly lift the bearing end of a
ring-pressed tension lever from the thread and thus release the latter from
e gripping pressure of said lever.
manner by
In the accompanying drawings Fig. 1 is a front side view of the improved
uttle and its bobbin-case, the shuttle being represented in the position which
assumes when it is about to take a loop of needle thread, and Fig. 2 is a
hilar view with the shuttle in a position far enough forward to have carried
oop of needle thread to a cast-off position around the bobbin-case; the said
bin-case being in section to illustrate the automatic tancis
D

page_text: detail view of the shuttle-pin and the locking and tension lever. Fig. 4 is a
detail view of the bobbin case, and Fig. 5 a detail view of the bobbin.
serves
The
A denotes a segmental oscillating or rotating shuttle, of well-known form,
provided with a loop-seizing beak a, and having at or near its axis or centre of
inovement a bobbin-case supporting pin a¹. B is a barrel or cylindrical bobbin-
case adapted to contain a long or cylindrical bobbin & and provided at one side
of its bobbin-chamber with a hole 61 to receive the pin a¹. The bobbin-case 13
is furnished with a prong or finger d to engage a stationary part of the shuttle
race to hold the said bobbin-case stationary while the shuttle oscillates or rotates
about it. E is a spring-pressed locking and tension lever provided with a small
lug e to enter an annular groove in the bobbin-case supporting-pin a¹ to lock
the said bobbin-case to said pin, the inner or lower end of said lever being
engaged by a spring which presses the upper or outer end of said lever towards
a bearing portion of the bobbin-case and between which bearing portion and
said lever the bobbin-thread runs on its way from the bobbin to the work
tension of the spring f may be regulated, to vary the tension, by a screw f
which attaches said spring to the bobbin-case. The lever E is provided with
the lip which overhangs the end of the bobbin-chamber 6 and thus
to retain the bobbin in said chamber. The pin a is pro-
vided, adjacent to the groove a², with a small eccentric or cam projection or
portion which is so arranged that when in the operation of the machine the
feed is advancing the work said projection will engage the tension lever E and
lift the bearing end of the said lever from the thread, and thus relax the tension,
"
automatic
the shuttle being thereby furnished within itself with an
or inter-
mittingly-acting tension device. To prevent the shuttle thread from running
entirely loose when its tension is thus relaxed a slight check spring e", which
bears constantly on the thread, is preferably provided. This check-spring, as
herein shown, is soldered or otherwise attached at its inner end to the lever E.
By the employment of a stationary "barrel" bobbin-case, to contain a cylin
drical bobbin, a bobbin, with a greater thread capacity relative to the size of
Also by pro-
the needle loops required to encompass the same may be used.
viding the stationary bobbin-case with a support which is at one side of the
bobbin-chamber thereof a long or extended bobbin-case supporting-surface or
pin may be employed, while the location of the bobbin-case eccentric to the
shuttle enables the latter as it advances into and expands a loop of needle thread,
to more and more closely approach the bobbin-case as said shuttle moves from
the position shown in Fig. 1 to that shown in Fig. 2, so that in the last-named
or cast-over position of the shuttle the bobbin-case is comparatively close up to
the periphery of the shuttle, thus requiring but a relatively small loop of needle
thread to go around the bobbin-case and enabling the shuttle to carry this loop
to the cast-over position by a relatively small circular movement which need be
but little, if any, more than 150°. This will permit the use of smooth and easy
movements of the shuttle-operating rock-shafts when the improved shuttles are
applied to oscillating shuttle machines, and when they are used in rotary shuttle
machines the objectionable and jerky differential movements of the rotating
shuttle shafts will not be necessary, and still plenty of time in the rotation of the
driving shaft for the proper and easy action of the feed and take-up will be
allowed. The automatic tension of the shuttle thread afforded by the improved
shuttle is also a desirable feature, as will be understood by those skilled in the
art to which the invention relates.
The bobbin-case B is "self-threading" in that it is provided with a thread
slot or passage running from the heel of the said bobbin-case to the thread
egress hole 65, and from said egress hole the thread runs between the bearing end
of the tension and locking lever E and the outer surface of the bobbin-case to
the delivery eye.or hole 66 whence it passes to the work, slots 6 being cu
between the lugs 68 and the body of the bobbin-case to enable the thread to be
drawn beneath the tension lever E and the check-spring e³, in threading. The

page_text: free end of the said check-spring is preferably loosely connected with the said
tension-lever, so that when the latter is lifted by pressing on the projection e
said check-spring will also be raised, for convenience in threading, the loose or
slotted connection of the free end of said check-spring with the lip 2 of said
lever permitting said check-spring to rest on the thread when the pressure of
the said lever is relieved from the thread by the slight lifting movement of said
lever produced by the cam or eccentric a³ with which the pin a¹ is provided.
The terms "automatic" and "intermittingly acting" as hereinbefore employed
in connection with the tension device are intended to be synonomous in that the
term automatic," as applied to a tension device, is now well known in the
art as referring to an intermittingly acting
device the frictional action of which is automatically varied during the formation
tension device, or a
of each stitch while the machine is in operation.
tension
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. The combination with a segmental sewing machine shuttle, of a bobbin-case
having a pivotal connection with said shuttle at a point which is concentric with
the curved periphery of the latter, or approximately so, but which is located out
of line, in the direction of the axis of the shuttle, with the bobbin-chamber of
the said bobbin-case.
2. The combination with a circularly-movable segmental sewing machine
shuttle having a centrally placed bobbin-case supporting pin, of a stationary
bobbin-case sustained by said pin and having a bobbin-chamber the longitudinal
axis of which is transverse to the axis of said shuttle, to contain a transversely
placed long or cylindrical bobbin.
3. A sewing machine shuttle provided with an intermittingly-acting tension
device for the shuttle thread, all of the parts of said tension device necessary
to secure the intermittent action being parts of said shuttle.
4. A sewing machine shuttle provided with an intermittingly-acting tension
device for the shuttle thread, all the parts of which tension device, necessary to
secure the intermittent action, are parts of said shuttle, combined with a check-
spring which serves to exert a light drag or tension on the thread when the
normal tension thereon is relaxed."
5. The combination with a circularly moving sewing machine shuttle provided
vith a bobbin-case supporting-pin having a cam
obbin-case having a tension lever or device to be operated by said cam or eccen-
or eccentric, of a stationary
ric to relax the tension on the shuttle thread at intervals when the machine is
n operation.
6. The combination with a circularly moving sewing machine shuttle provided
ith a bobbin-case supporting-pin having a cam or eccentric, of a stationary
obbin-case having a tension lever or device to be operated by said cam or eccen-
ric to relax the tension on the shuttle at intervals when the machine is in
peration, and a check-spring which serves to exert a constant light tension or
rag on the said thread when the normal tension is relaxed.
Dated this 16th day of th
1000
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents, 62, Saint Vincent Street, Glasgow,
Agent for the Applicant.