Improvements in Sewing Machines:
Year: 1891

page_text: Date of Application, 20th Feb., 1891
Complete Specification Left, 13th Nov., 1891-Accepted, 19th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in Sewing Machines:
I JOSEPH BUCHANAN ROBERTSON, Sewing Machine Mechanic of 184 Grosvenor
Street, Belfast in the County of Antrim, Ireland, do hereby declare the nature
of this invention to be as follows :-
This invention relates to sewing machines in which a circular raceway has
hitherto been used for the shuttle to move in, such machines being known by the
names of rotary or oscillating machines according to the movements of the shuttle
used in such machines.
My improvements to be hereafter described are of a twofold nature, one part
having for its object the dispensing with the shuttle raceway, thereby doing away
with the friction between the shuttle and raceway and consequent use of oil which
has a tendency to soil the work operated on and entailing additional labour and
expense to remove. Another part of my improvements is to do away with
irregular motion in the working parts of sewing machines, thereby enabling me to
construct a machine to run smoothly at a very high rate of speed.
In machines known by the distinctive names of rotary and oscillating there are
some. features common to both, and to those points of similarity, this invention
equally applies, namely each has a needle bar which is actuated.by the rotation of
at shaft usually running on bearings in the arm or upper portion of the machine,
and a shuttle with a centre post for carrying a bobbin of thread enclosed in a
case on the outside of which a tension spring is fitted to regulate the strain on the
thread to suit the class of work operated on, also each has a ring.or raceway in
which the shuttle moves, being usually actuated by a shaft (located under the bed-
plate of the machine) to one end of which a shuttle-carrier is attached..
When machines so constructed are driven at a high speed considerable friction
results from the centrifugal action of the shuttle, necessitating the use of oil which
is often detrimental to the work operated on. The object of this part of my
invention is to do away with the raceway and consequent friction and use of oil
by the use of a shuttle carrier so constructed that the centrifugal action of the
shuttle will be restrained by it, and the raceway becomes unnecessary. The
shuttle-carrier I use is similar in all respects to carriers suitable for the rotary
or oscillating shuttles and as used heretofore, that is to say having usually two
points or arms, one of said arms engaging with the shuttle near its point, the
other arm engaging with the heel of the shuttle during its forward motion.
.
To the shuttle-carrier so constructed I add another arm in a position that
it embraces the shuttle at the point where the greatest centrifugal action is
exerted, sufficient space being left between all the points of the carrier and shuttle
for the free passage of the thread. The tendency of the shuttle to fly outward
from its centre causes it to hear against the arm I have added, thereby closing
the passage for the thread, but this I overcome by causing the shuttle at a point,
of its revolution to be pressed clear of the arm by coming in. contact with a
projection fitted to the machine for that purpose and leaving a space through
which, the thread passes freely. To the bedplate of the machine I attach a plate
to keep the shuttle in position for taking and passing, through the loop. of needle-
thread and also to prevent the shuttle flying out of the shuttle-carrier.
In sewing machines of the class known by the name of rotary. it has been
hitherto.found:necessary. to have a variable. speed imparted either to the needle
in.relation. to the rotation.of the shuttle. or to the. rotation of the shuttle.in relation
to the reciprocating movements of the needle, such variable speed being for, the
purpose of enabling, the shuttle to get through the loop of needlethread in the

page_text: time allotted therefor by the reciprocation of the needle, it being essential in a
practical machine to let the shuttle take and cast off the loop of needlethread in
the shortest possible time or part of the cycle of movement of the shuttle and
thereby allow the greater amount of time in completing the cycle of movement to
enable the thread controller to take up the loop of needlethread and finish the
stitch before the feed operates to give place for the succeeding stitch.
This variation in speed is usually so regulated that the shuttle in passing
through the loop will travel about half a cycle or say 180 degrees in the same
period of time that the shaft actuating the needlebar moves about two-fifths of a
cycle or say 144 degrees, the shuttle now makes the other half cycle of 180 degrees
during the period of time occupied by the shaft actuating the needlebar to complete
its cycle of 216 degrees, thereby allowing time for taking up the needlethread and
operating the feed as before stated.
To accomplish this variation in the movements between the needle and shuttle
actions various mechanical contrivances have been used, all of which according to
this invention are dispensed with, and a uniform rate of speed allowed to exist
between the revolution of the shuttle and the reciprocation of the needle, and I
obtain the advantage of passing the shuttle through the loop of needlethread in
about 144 degrees of a cycle by the following means:
Heretofore the practice in the manufacture of machines has been to mount the
needlebar in a vertical line coincident with the axis of rotation of the shuttle and
thereby making it necessary that the shuttle should make one half of a revolution
from the taking of the loop when the shuttle point is up at the needle to the
point at which the cast off of the loop takes place, which is when the point of the
shuttle is at its lowest.
.
In my improved machine I mount the needlebar in a vertical line that will
bring the needle with its loop of thread to meet the shuttle at a point when it has
travelled about 36 degrees past the vertical line of its own axis at the highest
point, thus leaving only about 144 degrees for the shuttle to travel while passing
through the loop until it reaches its lowest point where the loop is cast off,
allowing 216 degrees of the cycle for the thread to be taken up and the feeding
of the material preparatory to making the next stitch.
By these means I obtain practically the same results as if the shuttle made half
a cycle with accelerated speed, with the advantage that I avoid all the jar and
shock to the working parts consequent on having a variation in speed twice in
each revolution of the shuttle, and further that I am able to run the machine at
a much higher rate of speed, the friction being reduced to a minimum.
Dated 19th day of February 1891.
JOSEPH BUCHANAN ROBERTSON.
COMPLETE SPECIFICATION.
Improvements in Sewing Machines.
I JOSEPH BUCHANAN ROBERTSON, Sewing Machine Mechanic of 184 Grosvenor
Street, Belfast, in the County of Antrim, Ireland, 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 :-
This invention relates to sewing machines in which a circular raceway has
hitherto been used for the shuttle to move in, such machines, being known by the
names of rotary or oscillating machines according to the movements of the shuttle
used in such machines.
My improvements to be hereafter described are of a twofold nature, one part
having for its object the dispensing with the shuttle raceway, thereby doing away
with the friction between the shuttle and raceway, and consequent use of oil
which has a tendency to soil the work operated on, and entailing additional
labor and expense to remove. Another part of my improvements is to do away

page_text: with irregular motion in the working parts of sewing machines, thereby enabling
me to construct a machine to run smoothly at a very high rate of speed.
In machines known by the distinctive names of rotary and oscillating there are
some features common to both, and to those points of similarity this invention
equally applies, namely each has a needlebar carrying an eye pointed needle
which is actuated by the rotation of a shaft usually running on bearings in the
arm or upper portion of the machine, and a shuttle with a centre post for carrying
a bobbin of thread enclosed in a case on the outside of which a tension spring is
fitted to regulate the strain on the thread to suit the class of work operated on,
also each has a ring or raceway in which the shuttle moves, being usually
actuated by a shaft (located under the bed plate of the machine) to one end of
which a shuttle-carrier is attached.
When machines so constructed are driven at a high speed considerable friction
results from the centrifugal action of the shuttle, necessitating the use of oil
which is often detrimental to the work operated on. The object of this part of
my invention is to do away with the raceway and consequent friction and use of
oil by the use of a shuttle-carrier so constructed that the centrifugal action of the
shuttle will be restrained by it, and the raceway becomes unnecessary.
The
shuttle-carrier I use is similar in all respects to carriers suitable for the rotary
or oscillating shuttles and as used heretofore, that is to say having usually two
points or arms, one of said arms engaging with the shuttle near its point, the other
arm engaging with the heel of the shuttle during its forward motion.
To the shuttle-carrier so constructed add another arm Figs. 4, 5 & 7 in a
position that it embraces the shuttle at the point where the greatest centrifugal
action is exerted, I do not however confine myself to the use of one additional
arm only as it is obvious two or more arms may be used for this purpose,
sufficient space being left between all the points of the carrier and shuttle for
the free passage of the thread. The tendency of the shuttle to fly outward from
its centre causes it to bear against the arm I have added, thereby closing the
passage for the thread, but this I overcome by causing a projection raised on the
periphery of the shuttle at a point of its revolution to be pressed clear of the arm
of the shuttle-carrier by coming in contact with another projection preferably a
roller adjustable as seen at Figs. 8 & 9 fitted to the machine for that purpose and
thereby leaving a space through which the thread may pass freely. To the bed-
plate of the machine I attach a plate I, in front of the shuttle to keep the shuttle
in position for taking and passing through the loop of needle thread and also to
prevent the shuttle flying out of the shuttle-carrier.
In sewing machines of the class known by the name of rotary it has been
hitherto found necessary to have a variable speed imparted either to the needle in
relation to the rotation of the shuttle, or to the rotation of the shuttle in relation
to the reciprocating movements of the needle, such variable speed being for the
purpose of enabling the shuttle to get through the loop of needle thread in the
time allotted therefor by the reciprocation of the needle, it being essential in a
practical machine to let the shuttle take and cast off the loop of needle thread in
the shortest possible time or part of the cycle of movement of the shuttle and
thereby allow the greater amount of time in completing the cycle of move-
ment to enable the thread controller to take up the loop of needle thread and
finish the stitch before the feed operates to give place for the succeeding stitch.
This variation in speed is usually so regulated that the shuttle in passing
through the loop will travel about half a cycle or say 180 degrees in the same
period of time that the shaft actuating the needlebar moves about two-fifths of a
cycle or say 144 degrees, the shuttle now makes the other half cycle of 180 degrees
during the period of time occupied by the shaft actuating the needlebar to
complete its cycle of 216 degrees, thereby allowing time for taking up the needle
thread and operating the feed as before stated.
To accomplish this variation in the movements between the needle and shuttle
actions various mechanical contrivances have been used, all of which according to

page_text: this invention are dispensed with and a uniform rate of speed allowed to exist
between the revolution of the shuttle and the reciprocation of the needle, and
obtain the,advantage of passing the shuttle through the loop of needle thread in
about 144 degrees of a cycle, by the following means: -
Heretofore the practice in the manufacture of machines has been to mount the
needlebar in a vertical line coincident with the axis of rotation of the shuttle as
seen at Fig. 2 and thereby making it necessary that the shuttle should make one
half of a revolution from the taking of the loop when the shuttle point is up at
the needle to the point at which the cast off of the loop takes place, which is when
the point of the shuttle is at its lowest.
In my improved machine Fig. 3 I mount the needlebar in a vertical line that
will bring the needle with its loop of thread to meet the shuttle at a point when
it has travelled about 36 degrees past the vertical line of its own axis at the
highest point, thus leaving only about 144 degrees for the shuttle to travel while
passing through the loop until it reaches its lowest point where the loop is cast off,
allowing 216 degrees of the cycle for the thread to be taken up and the feeding
of the material preparatory to making the next stitch.
By these means I obtain practically the same results as if the shuttle made half
a cycle with accelerated speed, with the advantage that I avoid all the jar and
shock to the working parts consequent on having a variation in speed twice in
each revolution of the shuttle, and further that I am able to run the machine at a
much higher rate of speed, the friction being reduced to a minimum.
This my said invention will be better understood by reference to the accompanying
drawings.
Fig. 1 is a plan showing my improved shuttle A. and carrier B in position as
seen looking at bottom of bedplate.
Fig. 2 is an end view in elevation showing the needlebar C and needle D in
vertical line through the axis of shuttle A as hitherto practised and suitable for
oscillating shuttle sewing machines.
Fig. 3 is an end view in elevation showing the needlebar C and needle D in
vertical line about 36 degrees of the shuttle's rotation from the central line of the
shuttle's axis for the purpose of doing away with variable motion in rotary shuttle
machines.
Fig. 4 is a front view of shuttle carrier B showing the additional arm Efor
restraining the centrifugal action of the shuttle A.
Fig. 5 is a section showing an edge view of the shuttle carrier B with the
additional arm E having a projection for engaging with the recess F of the
shuttle A.
Fig. 6 is a back view of the shuttle A. showing a recess F for engaging with
the projection of the arm E of the shuttle carrier B.
Fig. 7 shows the shuttle A and carrier B with the additional arm E engaging
in the recess F Fig. 6 of the shuttle A.
Fig. 8 is a view of the back of the shuttle A showing the projection G on the
periphery for clearing the passage for the thread by coming in contact with the
roller H Figs. 8 & 9 projecting adjustably from the machine as described. I is a
plate fastened to the bedplate of the machine to keep the shuttle in position for
taking and passing through the loop of needle thread and also to prevent the
shuttle flying out of the shuttle carrier.
Fig. 9 is a sectional view of roller H and method of fastening to the machine.
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 1
claim is-
.1st. The use of an additional arm or arms to the shuttle carrier for the purpose
of restraining the centrifugal action of the shuttle thereby enabling me to dispense
with the shuttle race as used hitherto in sewing machines in which oscillating or
rotary shuttles are employed substantially as described.

page_text: 2nd. Doing away with variable motion between the needle and shuttle actions
in a rotary sewing machine by mounting the needlebar out of the vertical line of
the axis of rotation of the shuttle to a line corresponding with about. 36 degrees
of the revolution of the shuttle, thereby enabling the shuttle to catch and pass
through the loop of needlethread while making about 144 degrees or about two-
fifths of its cycle, thus leaving about 216 degrees or about three-fifths of its cycle
of rotation for the purpose of taking up the needle thread and actuating the feed,
substantially as described and illustrated by the drawings annexed.
3rd. The use of a projection on the periphery of the shuttle for clearing the
passage of the thread by coming in contact with a projection or roller adjustably
fitted to the machine substantially as described and shown by Figs. 8 & 9.
Dated this 9th day of November 1891.
JOS. B. ROBERTSON.