IMPROVED APPARATUS APPLICABLE TO SEWING MACHINES FOR OVERCASTING
Year: 1881

page_text: LETTERS PATENT to John Imray, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for an Invention of "IMPROVED
APPARATUS APPLICABLE TO SEWING MACHINES FOR OVERCASTING." A
communication from abroad by Auguste Boisard, of Paris, France.
PROVISIONAL SPECIFICATION left by the said John Imray at the Office
of the Commissioners of Patents on the 24th November 1881.
JOHN IMRAY, of No. 28, Southampton Buildings, Chancery Lano, in th
County of Middlesex. "IMPROVED APPARATUS APPLICABLE TO SEWING
MACHINES FOR OVERCASTING." [A communication from abroad by Auguste
Boisard, of Paris, France.]
This Invention relates to apparatus applicable to sewing machines in which a
shuttle is employed for effecting the kind of stitching known as "overcasting."
For this purpose, in addition to the needle and shuttle, a hook is employed having
a series of movements given to it, such that it passes through the hole of the sewing
table, and turning under the edge of the fabric it seizes a loop of the shuttle thread,
it brings this loop up above the fabric and turns it into a position such that the
needle descends through the loop, which being then let go by the hook is drawn
tight by the passage of the shuttle through the bight of the needle thread below
the fabric. This series of movements being repeated for every stroke of the
needle and shuttle, stitching is produced presenting along the edge of the fabric a
series of loops of the shuttle thread, which above the fabric are passed through by
the needle thread, and the limbs of which below the fabric pass through successive
loops of the needle thread, constituting lock stitch overcasting. The required
movements are given to the hook in the following manner:-The hook is secured
to a nearly vertical spindle, which is capable of turning a little in bearings on a
nearly vertical lever. This lever has for its fulcrum a stationary pin working in a
slotted hole of the lever, so that the lever can oscillate on the pin and also move a
little up and down. At the upper end of the lever there is a hole of trapezoidal
shape in which works a pin on the one end of a nearly horizontal lever, the other
end of which bears on the top of the reciprocating needle bar, so that every upstroko
ID 611

page_text: of the needle an oscillating and a descending movement is given to the vertical
lever and to the hook which it carries, the hook being thereby made to descend
below the fabric and to seize a bight of the shuttle thread. During the down stroke
of the needle, springs cause the backward and upward stroke of the lever and
hook, an additional movement being given by the pin of the horizontal lever acting
on a spring wedge piece within the trapezoidal hole of the vertical lever, and thus
the hook is made to present to the needle the loop of the shuttle thread which it
carries, so that the needle descends through it and the hook thereupon lets it go.
Besides having the vertical reciprocation and the horizontal oscillation resulting
from the movements of the lever, the hook is also during its movements made to
turn a little on its spindlo as an axis, for which purpose an adjustable stud
projecting from its spindle is made to bear against a stationary inclined guide, and
the action of this guide in the one direction in opposition to a spring straining the
spindle in the opposite direction causes the hook, while it reciprocates, to turn a
little to and fro on its axis in such a manner as to catch the shuttle thread below
the fabric, and to let its loop go above the fabric when the needle has passed
through it. The two levers and the inclined guide for giving the hook its move-
ments as above described are conveniently arranged on a plate or frame which can
be secured by a clamping screw to the head of the sewing machine when overcasting
is required, and can be detached when the machine is employed for ordinary
sewing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Imray in the Great Seal Patent Office on the 20th May
1882.
JOHN IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of Middlesex. "IMPROVED APPARATUS APPLICABLE ΤΟ SEWING
MACHINES FOR OVERCASTING." A communication from abroad by Augusto
Boisard, of Paris, France.
This Invention relates to apparatus applicable to sewing machines, in which a
shuttle is employed for effecting the kind of stitching known as overcasting.
For this purpose, in addition to the needle and shuttle, a hook is employed having
a series of niovements given to it, such that it passes through the hole of the
sewing table and turning under the edge of the fabric it seizes a loop of the
shuttle thread, it brings this loop up above the fabric and turns it into a position
such that the needle descends through the loop, which being then let go by the
hook is drawn tight by the passage of the shuttle through the bight of the needle
thread below the fabric. This series of movements being repeated for every
stroke of the needle and shuttle, stitching is produced, presenting along the edge
of the fabric a series of loops of the shuttle thread, which above the fabric are
passed through by the needle thread and the limbs of which below the fabric pass
through successive loops of the needle thread, constituting lock stitch overcasting.
The required movements are given to the hook in the following manner:-The
hook is secured to a nearly vertical spindle which is capable of turning a little in
bearings on a nearly vertical lever. This lever has for its fulcrum a stationary
pin working in a slotted hole of the lever, so that the lever can oscillato on the
pin and also move a little up and down. At the upper end of the lever there is a
hole of trapezoidal shape in which works a pin on the one end of a nearly
borizontal lever, the other end of which bears on the top of the reciprocating
needle bar, so that at every upstroke of the needle an oscillating and a descending
movement is given to the vertical lever and to the hook which it carries, the hook
being thereby made to descend below the fabric and to seize a bight of the shuttle
thread. During the down stroke of the needle, springs cause the backward and
upward stroke of the lever and hook, an additional movement being given by the
pin of the horizontal lever acting on a spring wedge piece within the trapezoidal
hole of the vertical lever, and thus the look is made to present to the needle the
loop of the shuttle thread which it carries, so that the needle descends through it,
and the look thereupon lets it go. Besides having the vertical reciprocation and
the horizontal oscillation resulting from the movements of the lever the hook is
also during its movements made to turn a little on its spindle as an axis, for which
purpose an adjustable stud projecting from its spindle is made to bear against a
stationary inclined guide, and the action of this guide in the one direction in
opposition to a spring straining the spindle in the opposite direction causes the
hook, while it reciprocates, to turn a little to and fro on its axis, in such a manner
as to catch the shuttle thread below the fabric and to let its loop go above the
fabric when the needle has passed through it. The two levers and the inclined
guide for giving the hook its movements as above described, are conveniently
arranged on a plate or frame which can be secured by a clamping screw to the
head of the sewing machine when overcasting is required, and can be detached
when the machine is employed for ordinary sewing.

page_text: and Fig. 6 shews a modified arrangement for obtaining the lateral motion of the
hook. a and c are two levers pivotted to the plator attached to the head of the
sewing machine; the lever a is connected to c, and has its free end acted upon by
a stud b on the upper end of the needle bar, which in its upstroke moves the lever
from the position shown in Fig. 2 into that shewn in Fig. 3. The lever a has a
pin entering a trapezoidal aperture in the lever c, in which is a wedge shaped
piece j held by a spring against the outer side of the opening. In passing between
the ono edge of the piece j and the side of the aperture, the pin i on the descent
of the lever forces the piece j to one side and imparts a slight oscillating motion to
the lever c. This lever has a slotted hole at its middle, through which passes
a pin d fixed to the plate r, whereby it is enabled to receive both the lateral
oscillating motion above mentioned and a vertical reciprocating motion. At its
lower end the lever c carries the hook e, which by the above named movements of
the lever is caused to seize a loop of the shuttle thread below the fabric, to bring
it up over the edge of the fabric, and hold it so that tho needle can pass through,
and then to release the loop again. The downward motion of the levers a and c
is effected by the stud b of the needle bar, as before described, while the upward
movement is offected by the springs g and h¹ acting respectively on the levers a
and c.
The lateral movement imparted to c by the first part of the downward
motion of a as described, causes it to bring the hook to a position over the hole fin
the needle plate, and the continued descent of a then causes the hook to descend
through this hole so as to scize the loop of the shuttle thread. The needle bar
now commencing its downstroke frees the lever a, which is thereupon raised by
the spring g, thus imparting both an upward and a lateral motion to the lever c
and look e, causing the latter to bring up the loop of the shuttle thread through
the hole and present it to the needle. The lateral motion of the hook required
for this purpose is greater than that required on the downstroke, and this increased
motion is obtained by the pin i being made to pass along the opposite edge of the
piece to that along which it previously passed, the spring acting upon j having
forced this against the outer side of the opening as soon as the pin i has passed
down between them, as first described; thus tho lateral motion of the lever c is
increased to an extent equal to the width of the wedge piece j.
For imparting to the hook the desired direction and allowing it readily to
release the loop when necessary, it is carried by a cylindrical bar capable of
turning in bearings 2, q, attached to the lever c, so that the hook and its bar whilo
partaking of the motion of the lever can turn somewhat on its axis so as to give
a further lateral motion at the required moment.
In the arrangement shewn on the Drawing, which shows the application of the
Invention to a "Howe" machine, the needle arm itself in its up and down motion
comes in contact with a cam m fixed on the bar and thus imparts to the latter
the before mentioned partial rotary motion, a spring n bringing the bar and hook
back to the original position when released by the arm.
When the Invention is applied to other machines that have not got the arm Z,
the arrangement shewn at Fig. 6 is adopted; in this case the hook bar has a
socket provided with a projection that carries a regulating screw y, which cach
time that the hook is brought forward past the needle comes in contact with a
projecting stop on the plate r, and thus causes the bar and hook to turn to
the required extent for bringing it up to the needle; by this arrangement the
Invention may be applied to all descriptions of sewing inachines and the extent of
lateral motion may be accurately regulated thereby.
As shewn at Fig. 4, the hook e is fixed in a split socket at the end of the bar k
by means of a ring p having a screw that pinches the socket together, so that the
hook can be adjusted to any desired position in the bar.
Having thus described the nature of the said Invention and in what manner the
same is to be performed, as communicated to me by my foreign correspondent,
I claim,―
First. The method herein described of producing overcast stitching wherein the

page_text: shuttle thread is at each stitch raised by a hook over the edge of the fabric to be
sewn, and is there secured by the needle thread passing through its loop.
Second. The herein described combination of two levers, one of which carries a
hook, while the other is actuated by the needle bar, and which are so arranged
and actuated as to cause the hook to raise the shuttle thread over the edge of the
fabric and present it to the needle, which secures it above the fabric by passing
through the loop.
Third. Mounting the book referred to in the preceding claim on a bar carried by
the one lever, but capable of turning on its own axis so as to bring the shuttle
thread under the needle, such rotary motion of the hook bar being effected either
by the needle arm or by means of a regulating screw on the hook bar coming in
contact with a fixed stop, substantially as herein described and shewn on tho
Drawings.
Fourth. The herein described arrangement for imparting a greater lateral motion
to the lever e during the up stroke of the lever a than during the downstroke,
consisting of the pin i operating in combination with the wedge piece j held in the
opening of the lever c by a spring.
In witness whereof, I, the said John Imray, have hereunto set my hand and
seal, this Twentieth day of May, in the year of our Lord One thousand
eight hundred and eighty two.
JOHN IMRAY. (L.S.).