Improvements in Sewing Machines.
Year: 1891

page_text: Date of Application, 19th Jan., 1891
Complete Specification Left, 30th Sept., 1891-Accepted, 7th Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in Sewing Machines.
I EDWARD KOHLER of 81 Guilford Street, Russell Square in the County of
Middlesex, Engineer do hereby declare the nature of this invention to be as
follows:-
This invention has reference to that class of lock stitch sewing machines in which
a rotary hook carrying a bobbin is employed, the object of the invention being to
adapt such machines for use either as a lock stitch or a chain stitch machine,
at will.
To this end, I apply to the lock stitch machine a reciprocating loop holder to
receive the loop as it leaves the rotary hook, and retain it open to receive the
needle on its next descent.
This loop holder may consist of a narrow plate having at its front end a series of
prongs to enter and hold open the loop, and also to prevent the slack from escaping
from the holder, or of a main portion with prongs and a movable portion with
one or more prongs pivotted to the main plate, and arranged to close or open as
the loop holder reciprocates, to enter and to extend the loop for the passage of
the needle.
The loop holder reciprocates in a recess formed in the table to receive it, and
may be actuated by a rocking arm, suitably mounted, projecting through the
table, and operated by an excentric on the hook shaft, or in any other convenient
manner.
In some cases, I may find it desirable to slightly open the loop to receive the
loop holder, and this may be effected by increasing the width of the rotary hook
about the centre of its length.
Means will also be provided for throwing the loop holder in or out of action as
required.
Dated this 17th day of January 1891.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Sewing Machines.
I EDWARD KOHLER of 81 Guilford Street, Russell Square in the County of
Middlesex, 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 :—
The object of this invention is to render hook lock-stitch sewing machines of any
type capable of producing either a lock-stitch or chain-stitch at will.
In carrying out my invention, I combine with the sewing machine a reciprocating
forked loop holder, which is operated by suitable mechanism (when it is desired to
make a chain stitch, to take the loop off the loop former or hook, to hold it open,
and to bring it, while open, into position to receive the needle at its next descent.
In the accompanying drawings
Fig. 1 is an end view of so much of a hook lock-stitch sewing machine as is
necessary to shew the adaptation of my invention thereto.
Fig. 2 is an underside plan view.
Figs. 3, 34, 3, 4, 44, 4B, 5, 54, 5B, shew in diagrammatic form three different
positions assumed by the parts during the operation of forming the chain stitch.

page_text: The invention may be applied to any hook lock stitch machine, whether rotary
or oscillating, but the machine shewn in the drawings is that known in the trade as
the "Jones" rotary hook lock stitch machine......
As these machines are well known, it is unnecessary to describe them, or to shew
other than those parts necessary to explain my invention.
It may be well here to define what is meant in this Specification by the term
"hook "machine, in contradistinction to the term "shuttle" machine used in the
Specification of my English Patent No. 8231 of 1890.
By "shuttle" is meant a loop opening device to contain a spool or hobbin, and
capable of being reciprocated in a straight or curved path, or rotated or oscillated
in a circular race, and the body of which is entirely on one side of the line of the
needle.
وو
By "hook
is meant a loop opening device to contain a bobbin or thread
case, and capable of being rotated or oscillated in a circular race, and the body
of which extends on both sides of the line of the needle.
By means of the first named device, the formed loop is drawn entirely to one
side of the needle, whereas by the other device the formed loop is spread more or
less equally on both sides of the line of the needle.
"
It may be further remarked that a loop opening device consisting of a hook
oscillating in a circular race, the body of which extends on both sides of the needle,
is known in the trade as an 66
oscillating shuttle," and is used in some "Singer
machines, but for the purposes of this invention such device is classed under the
term "book."
Referring now to the drawings, A is the table of the machine, D is the
rotary hook corresponding to the shuttle in other lock stitch sewing machines.
This hook is set in a circular race, and is actuated through a shaft D' driven
in the way common to machines of this type.
The bobbin may be removed from the hook, or retained therein, as desired,
while making the chain, provided the thread be cut off short in the latter case.
E is the reciprocating loop holder (the general form of which is most clearly
shewn at Fig. 48), which consists of a plate having a fork E' and lateral projections
or horns E at its forward end, and a socket E' in its rear portion.
The fork E' is designed to enter the loop formed by the rotary hook D, and
hold it open for the next descent of the needle, and thereby produce a chain
stitch when desired.
The exact form of the loop holder may however be varied to some extent,
but in every case it will be provided with a fork, to enter and hold open the
loop. The reciprocation of the loop holder is effected by means of the pin f,
which takes into the socket E³ of the loop holder E.
""
In the "hook" machines; it will not be necessary for the loop holder to oscillate
as well as reciprocate, as in the shuttle machines, for the reasons before mentioned,
viz. that in the "shuttle machines the loop is drawn by the shuttle or opening
device entirely to one side of the needle, and to bring the open loop and present it
to the needle, it is evident that the loop holder with the loop upon it must be moved
sideways.
In the hook machine, the loop is spread so as to extend ou both sides of the
vertical axis of the needle, and consequently the loop holder may reciprocate in
line with the needle, and the sideways motion will be unnecessary.
At the same time I reserve to myself the right to give an oscillating motion
to the loop holder, if I find it necessary, such motion being produced; for
example, in the manner described in the Specification of my Patent before
referred to.
The pin is fitted to a collar Z, having a projecting arm Z1, and mounted loosely
on a sleeve Y, which is mounted loosely on the shaft X. This shaft X operates
to lift the feed dog F in the usual manner, and forms no part of the present inven-
tion. The arm carries the spring locking pin æ, by which the collar Z may be
locked to the sleeve Y, when desired, as will be well understood. The sleeve Y is

page_text: rocked through the arm V (keyed thereon) and connecting rod V1 by an
excentric T on the shaft D'. The loop holder E is therefore actuated from the
excentric T in such a manner, that a "dwell" is provided for at the most forward
point of its reciprocating motion, and a comparatively quick motion at another
part of its stroke. The above is a convenient arrangement for reciprocating the
loop holder, but any other arrangement may be employed without departing from
the nature of my invention.
Upon the underside of the throat plate, a short plate is fixed, close to the
needle hole, and in line with the travel of the loop holder E, the object of which
is, as the holder works forward, to jam the loop into the shoulders formed by the
horns or projections E of the loop holder E (see Fig. 5B) during the take up, so
"missed
that the slackened thread shall not jump off the fork E, and cause a
stitch." In some cases I may find it preferable to lengthen the projections E, and
curve them slightly inwards to effect the same object, and the plate z might perhaps
be dispensed with.
With a view to enlarge the width of the loop to such an extent as to ensure
the fork of the holder E entering the loop, I may secure on the side of the hook D,
a metal strip D, which slightly spreads the loop at its upper part.
The only change required to convert the lock stitch machine to a chain
stitch machine will be to adjust the locking pin or holt, to lock the collar Z
to the sleeve Y, and to remove the hook bobbin, or to sever the hook thread close
to the bobbin.
To change the chain stitch to the stitch, it is only necessary to bring the
loop holder E to its most backward position, and then unlock the bolt a, which will
permit of the sleeve rocking without moving the pin collar Z, and to replace the
hook bobbin.
It will thus be seen that besides the locking and unlocking of the parts, the only
other change necessary to change the stitch, is the removing and replacing of the
bobbin, a matter of almost hourly occurrence with sewing machinists, and one
that is well understood, or to cut off the hook thread, as before described.
Or, the hook thread may, if desired, be retained in work, when the hook thread
will be interlaced with the chain stitch formed by the needle thread and an
effective embroidery stitch will be produced, especially if the hook thread is of a
different color.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is :-
1. In a lock stitch sewing machine, the combination with an eye pointed needle
and a hooked loop opening device, of a reciprocating forked loop holder adapted
to enter and retain the loop, and hold the same open in the path of the needle at
its next descent, substantially as herein described.
2. A loop holder for lock stitch sewing machines, consisting of a plate having
at its front end a fork and lateral horns or projections, and near its rear end
a socket to receive a pin of the operating mechanism substantially as described.
3. The combination with a reciprocating loop holder, of a plate secured to the
underside of the throat plate in the line of travel of the loop holder, as and for the
purpose set forth.
4. As a driving mechanism for the loop holder in a hook lock stitch sewing
machine, the combination of the shaft D', excentric T, and connections, shaft X,
sleeve Y, pin collar Z on the sleeve, and the locking bolt x for locking the said
collar and sleeve together, substantially as herein described.
1001
NEWTON & SON,
Agents for the Applicant.