Improvements in Hem-stitch Sewing Machines.
Year: 1899

page_text: [Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of New
York, United States of America, Sewing Machine Manufacturers.]
Improvements in Hem-stitch Sewing Machines.
I, JOHN KING MACDONALD, 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 me, to be particu-
larly described and ascertained in and by the following statement;-
In the use of that class of hem-stitching sewing machines more particularly
adapted for "drawn" work from which some of the threads of the woven fabrics
have been drawn out (or omitted in the weaving) to form the openwork hem,
it is desirable that the divided groups of threads when once separated from each
other should be held apart until they have been secured in their divided positions
by the sewing threads. In the present invention this result is effectively accom-
plished by providing one or more piercers or thread-dividing spurs which are
connected with the feed-dog of the machine so as to reciprocate back and forth
therewith, or so as to partake of the feeding movements thereof, and also so con-
structed, arranged and timed as to have proper vertical thread-dividing and
disengaging movements. These vertical movements of the thread-dividing spur
or spurs connected with the feed-dog are preferably considerably greater than
the vertical movements of said feed-dog, although preferably timed to occur in
unison with said vertical movements of said feed-dog.
The present invention is more particularly adapted for use in that class of
machines in which the hem-stitching is effected by a single vertically and horizon-
fally reciprocating needle and in which the feed dog has imparted to it two
forward and one backward feeding movements for each three-stitch hem-stitch
figure or pattern, as in forming this hem-stitch figure or pattern the thread-
dividing spur or spurs will, when once engaged with the fabric to divide the
threads thereof, remain in the fabric and hold the divided threads apart until
the figure has been completed, and will then be disengaged from the fabric with
the feed-dog after the last forward feeding movement has taken place prior to
the commencement of a new hem-stitch figure.
In the accompanying drawings, Fig. I is a bottom view, with the shuttle
mechanism removed, of a well-known form of Singer hem-stitch sewing machine
embodying the present invention, Fig. 2 is a cross-section through the lower part
of the same on line 2-2, Fig. 1, with the feed-dog and thread-dividing, spurs in
raised positions, and Fig. 3 is a similar view with the feed-dog and spurs in
lowered positions. Fig. 4 is a detail plan view of the feed-dog and attached
spur-carrying lever, and Fig. 5 is a detail view of the spur-carrying lever detached.
A denotes the bed-plate of the machine beneath which is arranged a vibrating
and longitudinally reciprocating feed-lever B operated in the usual or a well-
known manner from the cam-wheel C. D is a rocker pivoted to the bed-plate
and having inwardly projecting arms between which is hinged the feed-bar E
to which is attached the feed-dog e, The feed lever is provided as usual with a
Гр. 077

page_text: wedge or incline which reciprocates beneath the feed-bar as said lever is moved
longitudinally and which wedge or incline governs the vertical movements of
said feed-bar. In the present instance the feed-bar is lowered and retracted by
springs b1, b2.
Pivotally attached to the feed-dog, at f, is a lever one arm fl of which is
arranged to impinge against the lower surface of the bed-plate against which said
arm is pressed by a spring 9 interposed between the feed dog and a part of said
lever; the other arm f² of said lever being provided with one or more (preferably
two) piercers or thread-dividing spurs f³, f, arranged a distance apart equal to
the length of feed for any particular class of work for which they may be intended.
The portion of the arm carrying the thread-dividing spur or spurs is preferably
formed separate from and adjustably secured to the part of the spur-carrying
lever. The lever f¹, f, f, being pivotally attached to the feed doge has bodily
vertical movements therewith, and as the feed dog is raised and lowered said
lever will have a vibrating movement on its fulcrum-pivot owing to the engage-
ment of the arm f¹ of said lever with the under surface of the bed-plate against
which said arm is held by the spring g. The spurs f³, f, are at some distance
from the fulcrum of said lever and they will have vertical movements in unison
with the vertical movements of the feed-dog, but considerably greater, so as to
perform their thread-dividing functions in an efficient manner when lifted, and
so as to be fully disengaged from the work when lowered and when they are to
be moved backward with the feed bar.
In the present machine, (in which the needle-bar and needle will have the
usual lateral movement of hem-stitch machines) the feed-dog will have two
forward and one backward feeding movements for each three-stitch hem-stitch
figure, the feed-dog being in its raised or feeding position during all of the time
when this three-stitch figure is being formed excepting after the formation of the
last stitch of the figure when said feed-dog is lowered and retracted. From this
it results that the thread-dividing spurs, rising and falling with the feed-dog,
will be lifted to divide the threads at the first stitch of the figure. The needle n
now descends adjacent to the rear spur f³ and as the feed-dog will be moved back-
ward (still in its raised position) between the first and second stitches of the
figure the needle at its second descent will enter the work adjacent to the forward
spur f. Between the second and third stitches of the figure and while the feed
remains lifted and with the spurs f³, f, in the work, the needle will be moved
laterally away from the said spurs, so that at its next descent it will enter the
fabric of the hem: the two descents of the needle adjacent to the thread-dividing
spurs being in the open-work portion of the hem, as will he understood. Thus
it will be seen that when the thread-dividing spurs have once been engaged with
the work, to divide the threads, they will remain in the work, moving backward
and forward with the feed, until the hem-stitch figure is completed, and thus
any displacement of the threads after they have once been divided will be
impossible.
The details of the machine may be varied widely for different classes of work,
as will be understood; as the present invention of a thread-dividing spur or spurs
movable back and forth with the feed-dog of a hem-stitch sewing machine having
a laterally moving needle and irregular feed is not confined to any particular kind
of such machine.
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. In a hem-stitch sewing machine, the combination with the feeding device
thereof, of one or more thread-dividing spurs which are independent of said
feeding device but which are connected therewith so as to partake of the back
and forth horizontal movements thereof.
2. In a hem-stitch sewing machine, the combination with the feeding device

page_text: thereof, of one or more thread-dividing spurs connected with said feeding device
so as to move back and forth horizontally therewith, and means for imparting
to said spur or spurs vertical movements greater than the vertical movements
of said feeding device.
3. In a hem-stitch sewing machine, the combination with a vertically and
laterally moving needle and a four-motioned feeding device timed to remain
lifted when the needle descends in the hem portion of the work, of one or more
thread-dividing spurs connected with said feeding device so as to be raised when
the latter is lifted, said spur or spurs remaining engaged with the work, to hold
the divided threads apart, while the side stitch is being made in the body of
the hem.
4. In a hem-stitch sewing machine, the combination with the feed-dog thereof,
of one or more thread-dividing spurs adjustably connected with said feed-dog.
5. In a hem-stitch sewing machine, the combination with a four-motioned
feed-dog, of a lever pivoted thereto, and thus movable back and forth therewith,
said lever being provided with one or more thread-dividing spurs, and means for
vibrating said lever on its pivot or fulcrum as said feed-dog is raised and lowered.
6. In a hem-stitch sewing machine, the combination with the four-motioned
feed-dog e, of a lever pivoted to said feed-dog one arm of which lever is arranged
to impinge against a fixed surface, as the under side of the bed-plate of the
machine, and the other arm of which is provided with thread-dividing spurs, and
a spring, as g, interposed between said feed-dog and a part of said lever.
Dated this 19th day of December 1899
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather, Chartered Patent. Agents,
62, Saint Vincent Street, Glasgow, Agent for the Applicant.