Improvements in Sewing Machines.
Year: 1892

page_text: Date of Application, 2nd Mar., 1892
Complete Specification Left, 2nd Jan., 1893-Accepted, 4th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Sewing Machines.
I EDWARD KOHLER of 307 High Holborn, London, Engineer do hereby
declare the nature of this invention to be as follows:-
This invention relates to that class of sewing machines in which the operation
known as <C overseaming" is carried out, and the invention consists in a novel
device whereby this operation may be effected in a simpler and more satisfactory
manner than heretofore.
In overseaming, the loop of the needle thread has to be brought from underneath
round the edge of the fabric and presented above the fabric in such a position that
the needle, at its next descent, shall pass through it.
In machines as at present constructed, this is effected by a curved arm mounted
in the end of a shaft below the table of the machine, the diameter of the curve of
the arm being such as to allow the arm to extend from below the table to above
the work. It will be obvious that, with such a curve, the throw of the vertical
needle must be considerable, and the take-up must be very great, so that the speed
at which the machine can be driven with safety is such that the machine is of
comparatively little practical use.
Now according to my invention I employ a reciprocating instrument of special
form, which I arrange to take the loop from the underside and close up to the
fabric, and bring it round the edge of the fabric, and present it to the needle at
its next descent.
The reciprocation of the instrument may be effected in any suitable manner, and
in addition to the reciprocation of the instrument, a rising and falling motion, and a
lateral motion, must also be given to the point of the instrument..
The object of the lateral motion is that the instrument which takes the loop on
one side of the needle, may present it to the needle above the work on the other
side of the needle.
The instrument consists of a thin blade set on edge, having at its front end, and
at its upper edge, a projecting finger, which is intended to enter the loop produced
as the needle withdraws through the fabric. At the root of the finger is a forwardly-
inclined recess (forming a kind of hook), into which the loop enters as the instrument
is drawn back, and is held until the instrument commences its forward movement
above the work.
At the same end of the instrument, and at its lower edge, is a second finger,
which, when the instrument is raised preparatory to its forward, movement above
the work, enters the loop, and holds it in the position to receive the needle at its
next descent.
The instrument is then free to withdraw from the loop (which is held by the
needle), so that it may be brought below the work, for the first named finger to
enter the new loop.
The stitch thus formed will be the ordinary chain button-hole or overseaming
stitch.
For double thread overseaming, the second finger is provided with an eye to
receive a thread from a separate bobbin, and the loop formed by this thread, is
presented to the needle at its next descent, instead of, the loop of the needle thread,
as is well understood.
A positive take-up, operated from a suitable cam; is used to take up the slack

page_text: and tighten the stitch, and for the feed I prefer to use a top feed, the operation
of which is now well known.
1000
NEWTON & SON,
Agents for the Applicant.
Improvements in Sewing Machines.
I, EDWARD KOHLER of 307 High Holborn, London, Engineer, 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 that class of sewing machines in which the operation
known as
overscaming" is carried out, and the invention consists in a novel
device whereby this operation may be effected in a simpler and more satisfactory
manner than heretofore.
In overseaming, the loop of the needle thread has to be brought from under-
neath, round the edge of the fabric, and presented above the fabric in such a
position that the needle, at its next descent, shall pass through it.
In machines as at present constructed, this is effected by a curved arm mounted
on the end of a shaft, below the table of the machine, the diameter of the curve of
the arm being such as to allow the arm to extend from below the table to above
the work. It will be obvious that with such a curve, the throw of the vertical
needle is considerable, and the take-up must necessarily be very great, so that the
speed at which the machine can be driven with safety, is such, that the machine is
of comparatively little usc.
Now, according to my invention, I employ a reciprocating instrument of special
form, which I arrange to take the loop from the needle on the underside and com-
paratively close up to the fabric, and to bring it round the edge of the fabric, and
present it above the same to the needle at its next descent.
The reciprocation of the instrument may be effected in any suitable manner,
and in addition to the reciprocation of the instrument, a rising and falling motion,
as well as a lateral motion, are given to the instrument.
The object of the lateral motion is, that the instrument which takes the loop
below the work on one side of the needle, may present it to the needle above the
work on the other side of the needle.
In the accompanying drawings,
Fig. 1, Sheet I, is a side elevation, partly in section, of so much of an over-
seaming sewing machine, as is necessary to illustrate my invention.
Fig. 2 is a plan view of the same.
Fig. 3 is a cross section on the line -, Fig. 2.
Figs. 4, 5, 6, and 7, Sheet II, partake of the nature of diagrams, to shew the
various positions of the overseaming instrument while making a stitch.
Fig. 8 is a plan view, and
Fig. 9 is a front view of Fig. 7.
Fig. 10 is a side view ;
Fig. 11 a plan view, and
Fig. 12 an opposite side view of the overseaming instrument, detached; and
Fig. 13 shews the formation of the instrument for making a double thread
stitch.
A is the table of the machine, which is of what is known as the "vertical

page_text: and D is an excentric on the same shaft for producing the rising and falling
motion of the instrument.
The overseaming instrument consists of a blade E, set on edge, having at its
front end an undercut hook portion E¹, and a pointed wedge-shaped portion E².
By the side of this blade is a second and springy blade E³, formed with an
upwardly projecting lug or enlargement E', having an inclined face (see Fig. 11).
This springy blade E³ corresponds in form to the blade E, except at the hook
portion, which is cut away, as shewn at Fig. 12.
This instrument is placed in a holder F, consisting of a socket at the end of a rod.
This holder F is pivotted to a link F', so that it may. oscillate horizontally, and
the link is so pivotted to a reciprocating slide F, that it may oscillate in a vertical
direction. To the underside of the slide F, is attached a pin F³, which works in
the groove of the cam C, by which the slide is reciprocated.
The holder F slides in a block G, which is connected by a ball and socket
joint to the strap of the excentric D.
The block G reciprocates and slides also vertically in guides G', which are set
at a slight inclination from the vertical, as seen in Fig. 3, which causes the lateral
movement of the instrument during its stroke.
H is a post secured to the table of the machine, and provided with an inclined
face on its inner side.
As the instrument moves forward above the work, the lug E strikes against
this post H, and as the inclined faces come together, the springy blade E is, so to
speak, prised open, and distends the loop, the needle passing down between the two
blades and through the loop (see Figs. 8 and 9).
In Fig. 4, the instrument is shewn as advancing below the work, and the hook
portion has just entered the needle thread loop thrown out as the needle rises.
Fig. 5 shows the instrument at the end of its forward stroke.
Fig. 6 shews the instrument when in its most rearward position, dragging on
the loop, and retaining it in the undercut portion of the hook, preparatory to
lapping it round the edge of the fabric. The instrument has also risen about one half
of its upward movement. Fig. 7 shews the instrument in its most forward position
above the work, in which position it will be seen the pointed wedge-shaped
portion E and the springy blade E³ have entered the loop, which has slipped out
of the hook portion.
The lug E has also struck against the post H, and the blades E and E³ are
open, thus distending the loop for the needle, which passes down between the
blades, as seen in Figs. 8 & 9. As soon as the needle is through the loop, the
instrument is withdrawn, and returned below the work, preparatory to taking up
or entering the new loop about to be formed.
For double-thread overscaming, the portion E2 of the instrument is slightly
enlarged, and it is provided with an eye for the second thread (see Fig. 13). The
recess of the hook is also deepened, so that the needle thread loop shall not be
brought up into position for the needle to pass through, the needle in this case
entering into the loop of the second thread as is well understood.
A positive take-up, operated from a suitable cam, is used to take up the slack
and tighten the stitch.
As, owing to the position of the instrument with respect to the work, the loop
is practically only of a sufficient length just to lap round the edge of the fabric,
and to receive the needle at its next descent, the amount of take-up is reduced to a
minimum, a matter of considerable moment in machines of this class.
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 an overseaming sewing machine, the use, for lapping the needle-thread loop
round the edge of the fabric, of a reciprocating loop-holding instrument, which

page_text: also receives an up and down movement and a lateral movement, as and for the
purposes set forth.
2. The loop-holding or overseaming instrument, constructed, arranged, and
operating substantially as herein shewn and described.
3. An overseaming sewing machine substantially as herein shewn and described.
Dated this 2nd day of January 1893.
NEWTON & SON,
Agents for the Applicant.