Improvements in Thread Controller Mechanism for Sewing Machines.
Year: 1895

page_text: Date of Application, 10th Sept., 1895-Accepted, 26th Oct., 1895
[Communicated from abroad by THE SINGER MANUFACTURING COMPANY, OF
New York, United States of America, Sewing Machine Manufacturers.]
Improvements in Thread Controller Mechanism for Sewing
Machines.
1, 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
particularly described and ascertained in and by the following statement:-
me to be
My invention relates to that class of sewing machines for forming lock stitches
by means of an under thread carried by a hook or shuttle co-operating with a
needle which carries the upper thread, and it has for its object to provide a take-up
or controller for the under thread which is arranged to be vibrated across the
vertical path of the needle. My improved thread controller is more particularly
designed for co-operation with oscillating hooks such as is shown by the Speci-
fication of Letters Patent No. 6450 of 1886, but may also be used in connection
with other stitch-forming mechanisms employing an under or locking thread, if
desired. In the operation of oscillating hooks which entirely support and carry
the bobbin case and bobbin, as shown by the said Patent, experience has
demonstrated that in making long stitches there is an objectionable friction
between the inside of the hook and the periphery of the bobbin-case, and which
friction my invention has for its object to obviate by the use of a thread-
slackening lever or controller.
In the accompanying drawings
Fig. 1 is a partial front view of a sewing machine illustrating the operation
of my invention, and Figs. 2 and 3 are similar views showing the parts in different
positions.
Fig. 4 is a partial bottom view of a sewing machine embodying my invention.
Fig. 5 is a detail view of the form of take-up or thread controller which I
prefer to employ, and Fig. 6 is a similar view of a slightly modified form of
controller lever.
Figs. 7 and 8 are detail views of the oscillating hook.
A denotes a portion of the work plate of a sewing machine and B a rotating
shaft arranged beneath said work plate and carrying a cam b. Pivoted to a
suitable plate or bracket a beneath the work plate A is the thread controlling
lever C herein shown as made in the form of a bell-crank, and provided at its
outer end with an enclosed opening c. The inner arm of said lever is provided
with a pin or roller d which enters the groove of the cam b, which latter serves
to vibrate the said lever.
E denotes a hook carried by an oscillating shaft E', the said hook being
essentially the saine in construction and operation as that shown by the Specification
of Letters Patent No. 6450, hereinbefore referred to, in that it is provided with a
loop seizing beak e and with a mouth or thread escape passage el between said beak
and the heel portion of the book. The said hook is furnished with a thread-
carrying bobbin contained within the bobbin case f, the latter having a suitable
opening from which the thread emerges, and the said bobbin case being, in practice,
provided with a suitable tension device. The bobbin case is retained in the hook
by a swinging latch f¹ which may be swung aside, as shown in dotted lines in
Fig. 1, for the insertion or removal of the bobbin case and bobbin.

page_text: In the operation of this oscillating hook the beak thereof advances, after the
needle has descended to its lowest point and has commenced to rise, and seizes the
loop of needle thread thrown out from said needle, the hook continuing its forward
movement until it has performed slightly more than a half revolution to carry the
loop of needle thread around beneath the centre of the bobbin case contained in
said hook; the hook now reverses its movement so as to bring the mouth e' thereof
again upward when the loop of needle thread is drawn up by the usual take-up
above the work plate and out of the said mouth, but in this operation of carrying
the needle thread around the bobbin case there is sometimes an objectionable
friction which it is the design of my special thread controller, when used in ccn-
nection with this form of lock stitch mechanism, to lessen. By reference to Fig. 1
it will be seen that the thread controller is in such position that its opening is
immediately below the needle opening on the work plate so that as the needle
descends it passes through the said opening of the thread controller. When the
needle has risen and the oscillating hook has moved around to the position shown
in Fig. 2, at which time the loop of needle thread has been partly carried around
the bobbin case by the oscillating hook (so as to be drawn up around the last side
of the bobbin case by the usual take-up above the work-plate) the thread con-
troller C has moved to the position shown in the said Fig. 2, thereby drawing the
bobbin thread taut, and by the tension thereon slightly lifting the bobbin case in
the oscillating hook so that the loop of needle thread may pass around the lower
side of the bobbin case with but little friction. When the oscillating book has
completed its backward movement and is in the position shown in Fig. 3 the thread
controller has moved to the opposite or forward side of the vertical path of the
needle for the purpose of drawing off sufficient thread from the bobbin to permit of
the easy formation of the next succeeding stitch.
My improved thread controller is more particularly desirable or necessary when
very long stitches are being made, as in such operation of the machine the bobbin
thread requires to be manipulated in the manner described in order to enable the
machine to run perfectly.
y
In order to prevent the bobbin thread which has been slackened by the thread
controller C from catching on the point or beak of the oscillating hook, when the
latter moves forward, I provide the outer portion of the said hook with a peripheral
flange which serves as a guard to bold the slackened bobbin thread away from
the point or beak of the hook. The end of the said flange y adjacent to the month
or opening is preferably curved inwardly, as more clearly shown in Fig. 8, and
it also tapers down to a blunt point, this construction thereof preventing the bobbin
thread from catching thereon or getting under the same in operation.
Instead of providing the outer arm of the thread controlling lever with an
enclosed opening e, as shown in Fig. 5, the said lever may be forked at its outer
end, as shown in Fig. 6; or in other words, the said opening c¹ of the form of lever
shown in Fig. 6 will consist merely of the space between two prongs of the fork,
instead of being an enclosed opening or slot, as shown in Fig. 5.
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 needle, of an oscillating hook
having a bobbin case for containing a bobbin and which bobbin case is supported
and carried by said hook, the latter being provided with an opening or mouth
between its beak and heel, and a horizontally placed thread controller arranged
beneath the work-plate of the machine and having an opening through which the
said needle descends and the outer arm of which controller is vibrated across the
vertical path of the needle in a direction transversely of the machine or
approximately in the line of the feed of the work.
2. In a sewing machine, the combination with the needle, of the threadl
controller C having a slot or opening arranged to cross the vertical path of the

page_text: said needle, the rotating cam by which said controller is operated, and the
oscillating hook E having a beak e and a mouth or thread escape passage e¹ between
said beak and the heel of the hook, the body of the hook being provided with the
peripheral flange or guard g to hold the slackened bobbin thread away from the
beak of the said shank.
3. In a sewing machine, the combination with the needle of the thread
controller C having a slot or opening arranged to cross the vertical path of the
said needle, the rotating cam by which said controller is operated, and the
oscillating hook E having a beak e and an opening or mouth or thread escape
passage e between said beak and the heel of the hook, the body of the hook being
provided with the peripheral flange or guard g to hold the slackened bobbin thread
away from the beak of the said hook, and the end of said flange, adjacent to said
mouth or thread escape passage, being curved inwardly and tapered to a blunt
point, substantially as shown and described.
Dated this 9th day of September 1895.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 Saint Vincent Street, Glasgow, Agent for the Applicant