Improvements in Shuttles and Shuttle Carriers for Sewing Machines.
Year: 1887

page_text: Date of Application, 26th July, 1887
Complete Left, 26th Apr., 1888
Complete Accepted, 1st June, 1888
PROVISIONAL SPECIFICATION.
Improvements in Shuttles and Shuttle Carriers for Sewing
Machines.
I, JOHN KING MACDONALD, Manager of the Singer Manufacturing Company of
Kilbowie, Dumbartonshire, do hereby declare the nature of this invention (as com-
municated to me from abroad by the Singer Manufacturing Company, of New
York, in the United States of America, Sewing Machine Manufacturers), to be as
follows: :-
My invention relates to that class of cylindrical sewing machine shuttles open at
their rear ends and provided with open-ended threading slots, such shuttles being
commonly known as "open-ended" and "self-threading." The object of my invention
is to provide a shuttle, of the class referred to, which will be simple in construction
and convenient for use and from which the thread will run with a uniform tension
without danger of catching on any part of the shuttle.
In connection with my shuttle I prefer to use a shuttle carrier constructed in such
a manner that the loops of needle thread can pass around the shuttle with the greatest
possible ease and smoothness.
In carrying my invention into effect I provide the shell or body of my open-ended
shuttle with an open-ended threading slot extending from the heel of the shuttle, at
the lower side or bottom of the shuttle shell, forward and upward to the top of said
shell-at a point near the forward end of the bobbin-cavity whence it runs rearward
for a short distance to a thread-delivery hole or aperture, the rearwardly extending
portion of said slot flaring forwardly so that the thread runs easily into it in threading.
The point between the forward and rearward parts of the threading slot is preferably
depressed slightly below the adjacent portions of the outer surface of the shuttle-shell
so as to facilitate threading when the hobbin is inserted in the shuttle so that the
thread runs from the top thereof, but preventing threading when the bobbin is
inserted so that the thread runs from the bottom thereof. With this construction it
is possible to thread the shuttle when the bobbin is almost empty, without difficulty,
if the bobbin be rightly inserted. The tension spring is provided with a single down-
wardly bent thread finger entering a small recess in the shuttle-shell, said spring also

page_text: having, on its under side, a slight groove to guide the thread. to proper tension
position and hold it there.
The carrier which I prefer to use with my shuttle has two bearing portions near
the opposite ends of the shuttle on which portions the shuttle is supported. This
construction of the carrier affords three clearances for the loops of needle thread
around the shuttle, the first of these clearances being near the nose of the shuttle
forward of the front bearing portion of the carrier-The second or central clearance
is afforded by a long hollow or depression between the front and rear bearing
portions of the carrier, and the third is at the heel of the shuttle. The rear horn
of the carrier is also hollowed out and bent or inclined so that only its rear upper
corner will bear against the shuttle. The shuttle is provided on its front face with
the usual flattened portions bearing against the shuttle race and with an ordinary
recess near its forward end into which the front horn of the carrier projects, and
when held in the carrier there is only sufficient room for the coarsest thread to
pass between the shuttle and the carrier and race except at the clearances above
noted. Thus the shuttle is so held as to prevent rolling or turning in the carrier
or the pulling up of the heel of the shuttle by the loops of needle thread, and
breaking or bruising of said thread between said heel and the angle or upright
portion or rear horn of the carrier is avoided.
The shell of the shuttle is provided with an open ended threading slot extending
from the heel of the shuttle at the lower side thereof forward and upward to a point
near the forward end of the bobbin-cavity and beneath the forward end of the
tension spring, whence it runs rearward into a thread delivery hole or aperture, the
rearward or return portion of said slot flaring forwardly or converging rearwardly,
so that it is widest at its forward send-The point between the forward and return
portions of the slot is preferably depressed slightly below the adjoining portions of
the outer surface of the shuttle-shell, this construction facilitating the passage of the
thread around said point in threading the shuttle when the bobbin is inserted in
the shuttle so that the thread runs from the top of the former, but preventing
threading when the bobbin is wrongly inserted-The shuttle is provided with the
usual flattened faces which fit against the shuttle race the lower side of the forward
flattened face being rounded off to prevent abrading or cutting the needle thread as
the loops thercof pass around the shuttle.
The tension spring is provided with a single thread finger entering a recess in the
shuttle shell, said finger preventing the escape of the thread from beneath the said
spring. To guide the thread into proper tension position and to keep it in place
against the flattened portion of the shuttle I prefer to provide the lower face of said
spring with a slight groove or recess.
The shuttle carrier is provided with two bearing portions on which the shuttle
rests, so as to afford three clearances for the thread between the shuttle and carrier,
the central clearance being due to the hollow or depression between the said bearing
portions. The overhanging front horn of the carrier extends into an ordinary recess
near the nose of the shuttle. The upwardly projecting rear horn of the carrier is
bent or hollowed out so as to afford a clearance for the thread around the lower part
of the heel of the shuttle, said horn being also preferably inclined horizontally, so as
to flare outward slightly from the shuttle. From this construction it results that the
said horn will bear against the shuttle only at one point, and that at the rear side
thereof at some distance above the bottom of the heel, and thus the shuttle will be so
held as to prevent the heel thereof from jumping up as the loops pass.
With the carrier constructed as above described it is obvious that the shuttle will
come in contact with the same only at the front and rear horns (alternately) and at
the bearing portions on which the shuttle rests, so that the shuttle may be held in
the carrier against the shuttle-race with so nice a fit that there need be no more space
around the shuttle at the contact points than is required for the passage of the
heaviest or coarsest thread between the shuttle and the shuttle-race and carrier, the
thread passing easily at the clearances. Thus the shuttle will be held so firmly that
rolling thereof (an objection peculiarly incidental to cylindrical shuttles) will be

page_text: effectively prevented, and the shuttle will have no tendency to rise from the carrier even
when the machine is run at a high speed with the shuttle slides removed, the peculiar
shape of the rear horn of the carrier and the construction of the latter by which the
clearances described are afforded permitting so close a fit of the shuttle between the
carrier and race that the greatest possible quietness and smoothness of action is
secured.
The shuttle is threaded simply by drawing the thread forward into the slot and
then rearward into the thread delivery hole and beneath the thread finger. As the
opening of the slot at the heel of the shuttle is at the lower side thereof it is quite out
of the way of the shuttle thread so that the latter cannot by any possibility catch
therein, and the spiral form and extent of the twist of the said slot effectively
prevents any catching of the loops of needle thread therein as they pass around the
shuttle.
n
1 11
1
T.L 1007
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.

page_text: 1, JOHN KING MACDONALD 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 relates to that class of cylindrical sewing machine shuttles open at
their rear ends and provided with open ended threading slots such shuttles being
commonly known as "open ended" and "self threading."
The object of my invention is to provide a shuttle of the class referred to which will
be simple in construction and convenient for use, and from which the thread will
run with a uniform tension without danger of catching on any part of the shuttle.
In connection with my shuttle I prefer to use a shuttle carrier constructed in
such a manner that the loops of needle thread can pass around the shuttle with the
greatest possible ease and smoothness.
In carrying my invention into effect, I provide the shell or body of my open ended
shuttle with an open ended threading slot extending from the heel of the shuttle, at
the lower side or bottom of the shuttle shell, forward and upward to the top of said
shell at a point near the forward end of the bobbin cavity, whence it runs rearward for
a short distance to a thread delivery hole or aperture, the rearwardly extending portion
of said slot flaring forwardly, so that the thread runs easily into it in threading. The
point between the forward and rearward parts of the threading slot is preferably
depressed slightly below the adjacent portions of the outer surface of the shuttle shell,
so as to facilitate threading when the bobbin is inserted in the shuttle so that the thread
runs from the top thereof, but preventing threading when the bobbin is inserted so
that the thread runs from the bottom thereof. With this construction it is possible to
thread the shuttle when the bobbin is almost empty without difficulty if the bobbin be
rightly inserted. The tension spring is provided with a single downwardly bent
thread finger, entering a small recess in the shuttle shell, said spring also having on
its under side a slight groove to guide the thread into proper tension position and hold
it there.
The carrier which I prefer to use with my shuttle has two bearing portions near
the opposite ends of the shuttle on which portions the shuttle is supported. This
construction of the carrier affords three clearances for the loops of needle thread around
the shuttle, the first of these clearances being near the nose of the shuttle forward of
the front bearing portion of the carrier. The second or central clearance is afforded
by a long hollow or depression between the front and rear bearing portions of the
carrier, and the third is at the heel of the shuttle. The rear horn of the carrier is also
hollowed out and bent or inclined so that only its rear upper corner will bear against
the shuttle. The shuttle is provided on its front face witli the usual flattened portions
bearing against the shuttle race ud with an ordinary recess near its forward end,

page_text: into which the front horn of the carrier projects, and when held in the carrier there is
only sufficient room for the coarsest thread to pass between the shuttle and the carrier
and race except at the clearances above noted. Thus the shuttle is so held as to
prevent rolling or turning in the carrier or the pulling up of the heel of the shuttle
by the loops of needle thread, and breaking or bruising of said thread between said
heel and the angle or upright portion or rear horn of the carrier is avoided.
In the drawings Figure 1 is a top view, slightly turned over, of a shuttle embodying
my invention; Fig. 2 is a similar view with the tension spring removed; Fig. 3 is a
side view of the shuttle shell, partly in section; Figure 4 is a bottom view of my
shuttle Figs. 5, 6 and 7 are detail views of the tension spring, Fig. 7 being a section
on the line 7---7 in Fig. 5; Fig. S is a plan view of my shuttle and carrier, and
Fig. 9 shows the carrier in section and the shuttle in elevation.
A denotes the shuttle shell or body and B the tension spring secured thereto in the
nsual manner by an attaching and adjusting screw k. The shell A is provided with
an open ended threading slot a, extending from the heel of the shuttle at the lower.
side thereof forward and upward to a point near the forward end of the bobbin cavity
and beneath the forward end of the tension spring, whence it runs rearward into a
thread delivery hole or aperture b, the rearward or return portion of said slot flaring
forwardly or converging rearwardly, as clearly shown in Fig. 2, so that it is widest at
its forward end. The point c between the forward and return portions of the slot a is
preferably depressed slightly below the adjoining portions of the outer surface of the
shuttle shell (see Fig. 3.) this construction facilitating the passage of the thread around
said point in threading the shuttle when the bobbin is inserted in the shuttle so that
the thread runs from the top of the former, but preventing threading when the bobbin
is wrongly inserted. The shuttle is provided with the usual flattened faces d and d¹,
which fit against the shuttle race the lower side of the forward flattened face, d,
being rounded off at e to prevent abrading or cutting the needle thread as the loops
thereof pass around the shuttle.
The tension spring B is provided with a single thread finger, f, entering a recess g
in the shuttle shell, said finger preventing the escape of the thread from beneath the
said spring.
To guide the thread into proper tension position and to keep it in
place against the flattened portion m of the shuttle, I prefer to provide the lower
face of said spring with a slight groove or recess h (shown in Fig. 7 and indicated by
the dotted line in Fig. 5.)
The shuttle carrier C is provided with two bearing portions, and on which the
shuttle rests, as shown in Fig. 9 of the drawings so as to afford three clearances 1,
2 and 3, for the thread between the shuttle and carrier, the central clearance, 2, being
due to the hollow or depression between the said bearing portions. The overhanging
front horn, n, of the carrier extends into an ordinary recess o near the nose of the
shuttle. The upwardly projecting rear horn, p, of the carrier is bent or hollowed out,
so as to afford a clearance, 4, for the thread around the lower part of the heel of
the shuttle, said horn being also preferably inclined horizontally, as shown in figure 8,
so as to flare outward slightly from the shuttle. From this construction it results
that the said horn will bear against the shuttle only at one point, and that at the rear
side thereof at some distance above the bottom of the heel and thus the shuttle will
be so held as to prevent the heel thereof from jumping up as the loops pass.
With the carrier constructed as above described, it is obvious that the shuttle
will come in contact with the same only at the front and rear horns (alternately) and
at the bearing portions i and , so that the shuttle may be held in the carrier
against the shuttle race D with so nice a fit that there need be no more space around
the shuttle at the contact points than is required for the passage of the heaviest or
coarsest thread between the shuttle and the shuitle race and carrier, the thread
passing easily at the clearances. Thus the shuttle will be held so firmly that rolling
thereof (an objection peculiarly incidental to cylindrical shuttles) will be effectively
prevented, and the shuttle will have no tendency to rise from the carrier even when
The machine is run at a high speed with the shuttle slides removed the peculiar shape

page_text: of the rear horn of the carrier and the construction of the latter by which the
clearances described are afforded permitting so close a fit of the shuttle between the
carrier and race that the greatest possible quietness and smoothness of action are
secured.
The shuttle is threaded simply by drawing the thread forward into the slot a and
then rearward into the thread delivery hole band beneath the thread finger f. As the
opening of the slot a at the heel of the shuttle is at the lower side thereof, it is
quite out of the way of the shuttle thread, so that the latter cannot by any possibility
catch therein, and the spiral form and extent of the twist of the said slot effectively
prevents any catching of the loops of needle thread therein as they pass around the
shuttle.
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. A sewing machine shuttle shell having a threading slot extending first forward
and then rearward, and a thread delivery aperture, into which the said slot leads, the
rearward or return portion of said slot flaring forwardly, or being widest at its forward
end substantially as set forth.
2. A sewing machine shuttle shell have a threading slot extending forward and
then rearward, the outer surface of the point between the forward and rearward or
return portions of said slot being below or within the adjacent outer surface of said
shell substantially as set forth.
3. An open ended sewing machine shuttle shell having an open ended threading
slot extending from the lower side of the said shell forward and upward to a point
near the forward end of the bobbin cavity and thence rearward to a thread delivery
aperture.
4. An open ended sewing machine shuttle shell having an open ended threading
slot extending from the lower side of said shell forward and upward to a point
beneath the tension spring and thence rearward to a thread delivery aperture.
5. The combination, with a sewing machine shuttle shell, having an open ended
threading slot extending from the lower side of said shell forward and upward to a
point near the forward end of the bobbin cavity on the upper side of said shell and
thence rearward to a thread delivery aperture, of a tension spring having a thread
finger extending into a recess in the said shell rearward of the said aperture
substantially as set forth.
6. The combination with a sewing machine shuttle shell having a flattened outer
surface over which the thread passes of a tension spring, having on its under side a
groove or recess for guiding the thread into proper tension position and keeping it
there, substantially as set forth.
7. A sewing machine shuttle carrier open at its top and having an overhanging
front horn and an upwardly projecting rear horn and two bearing portious adapted to
come beneath the shuttle near the ends thereof with a recessed or hollowed out portion
between said bearing portions, substantially as set forth.
8. A sewing machine shuttle carrier open at its top and having an overhanging
front horn and an upwardly projecting rear horn and two bearing portions adapted to
come beneath the shuttle near the ends thereof with a recessed or hollowed out portion
between said bearing portions to afford a central clearance for the thread, said carrier
having also clearances for the thread forward and rearward of said bearing portions,
substantially as set forth.
9. The combination with a sewing machine shuttle, of a carrier provided with an
upwardly projecting rear horn and having also a recess or clearance, as 3, below the
heel of the shuttle, and a clearance, as 4, between said heel and the said rear horn of
the carrier substantially as set forth.
10. The combination, with a sewing machine shuttle, of a carrier having a bearing,
as, just forward of the shuttle heel, a thread clearance, as 3, rearward of said

page_text: bearing, and an upwardly-projecting rear horn having a bearing or contact point for
the shuttle heel above the lower edge of the latter with a clearance, as 4, below said
bearing, substantially as set forth.
11. The combination, with a sewing machine shuttle, of a carrier having an over-
hanging front horn, two bearings, as i and i, affording front, central and rear thread
clearances, 1, 2 and 3 at the points where the loops of needle thread are spread, drawn
along, and pulled up respectively, said carrier having also an upwardly projecting rear
horn provided with a bearing or contact point for the shuttle heel above the bottom or
lower side of the latter, leaving a clearance, as 4, below said bearing or contact point
substantially as set forth.
12. The combination with a sewing machine shuttle having flattened faces d and d¹,
the former rounded off on its lower side, as at e, of a shuttle carrier provided with
the bearings i and ¹, affording the thread clearances 1, 2 and 3, said carrier having
also an upwardly projecting rear horn adapted to bear against the heel of the shuttle
above the lower side of the latter, with a clearance, as 4, rearward of said heel below
the bearing point of the said horn, substantially as set forth.
711
L
1
1
*11000
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow,
Agents.