Year: 1888

page_text: Date of Application, 19th July, 1888
Complete Specification Left, 20th Apr., 1889
Complete Specification Accepted, 1st June, 1889
1, CORNELIUS MUNDY 28 College Avenue, Leicester, Mechanic, do hereby declare
the nature of this Invention to be as follows:-
This Invention which has for its object improvements in sewing machines relates to
an improved double thread chain stitch sewing machine which can be converted at
pleasure into a single thread chain stitch machine and which is further capable of
making one or more lines of single or double thread chain stitching at the same
time, the said machine having an improved trimming or cutting apparatus in
combination with it but which apparatus may also be adapted to other sewing
machines.
The improved stitch forming mechanism consists of a new or improved form of
looper which is firmly fixed to a rock shaft which receives its motion direct from the
main rotary shaft through the medium of cranks and connecting rod the rock shaft
moving only through a quarter of a circle or thereabouts and in the same line as the
feed. The looper has the form of a curved or circular hook arising from a central
disc which is passed on the rock shaft and scrawed to a solid disc so that it becomes
virtually a part of the rock shaft and whilst it is adjustable at the screws in all
directions when desired it is not liable to that looseness in action which is invariably
the result of a multiplicity of parts and loose connections. The looper though capable
of being employed and lending itself readily for the purpose of making a single
thread chain stitch is principally intended for inaking a double thread chain stitch and
is thus required to carry a separate thread which is conducted through several eyelets
along grooved channels to the eye at its point. In order that the looper thread
be safely controlled the looper is curved sideways so that when it takes the loop from
the needle on the one side the loop is carried over to the other side as the looper
advances and also the looper thread along with it the looper on its return drawing the
two threads backward into a recess or slot cut in the underside of the needle plate
and holding them there until the needle has descended sufficiently to catch the looper
thread when the two threads are released and the stitch completed.
may
Another feature of the improved mechanism is a novel thread take-up device acting
upon the looper thread, and for which purpose the looper itself is partly available.
The looper thread being passed over thread guides fixed to the under side of the needle
plate well in advance of the eye at the heel of the looper, when the looper is brought
forward as far as it will come the thread is merely passed from heel to point and from
point to heel of the looper according to its backward or forward movement. The

page_text: looper therefore supplies itself with slack thread and takes the thread up again by this
arrangement of the guides. The arrangement however does not answer completely
the requirements of a proper thread take up but renders it necessary to deal with only
a very small portion of the slack thread which otherwise would have to be provided
for by independent means. To supplement this take up arrangement and render it
thoroughly efficient and positive a quadrant or radial arm is employed which quadrant
is a solid extension from the central disc of the looper on the opposite side to the
hook or beak of the looper and also opposite the thread guides on the needle plate.
The quadrant operates to take up the thread whilst describing an arc in relation to the
thread guides the centre line of the are being the point at which the quadrant takes
up most thread, and it is made in any suitable form which will prevent the thread
being caught by any projections from the central disc. The quadrant arm has also a
number of eyelets through any one of which the thread may be passed in order to
tighten it at any point of the looper's movement which tightening is most required
just when the needle is entering the looper thread. Though fixed on the rock shaft,
the quadrant may be secured separately from the looper and instead of passing the
thread through eyelets the quadrant may be adjusted to different positions by means
of screws or other equivalents if so desired. In using this take up the thread is
brought over one guide on the needle plate thence through one of the eyelets in
conjunction with the guides and then over the other guide on to the looper.
Another feature of the improved mechanism is an automatic tension device and
thread pull off acting upon the looper thread so as to produce a superior elastic stitch.
The said automatic tension may be in the form of a flat spring fixed at one end by
means of a washer and screw to the underside of the bed plate; or, it may be in the
form of a lever having its fulcrum fixed in like manner and pressed by means of a
flat or a coil spring while the other end is lifted at the right time for releasing the
thread by means of a quadrant fixed on the rock shaft or by a portion of the cutting
apparatus in combination with the machine and hereafter to be described. The pull
off may be in the form of a hook or loop or a flat wing having a number of eyelets
and fixed to the rock shaft by means of a screw or a split boss made to fit the shaft
tightly. It can thus be adjusted to pull off from the reel any desired quantity of
thread as the rock shaft moves forward and on its return movement allow the same
to be drawn through the lifted tension by the looper without any resistance except
the friction of the guides through which it has to pass thus measuring at each repeated
movement the quantity of thread to be used or fixed in each stitch. Thread guides
are suitably placed to aid in performing these operations. To assist in guarding the
upper needle and in forming a loop of the needle thread a flat finger is employed.
The said finger has a central disc like the looper and is fixed on the rock shaft in a
similar manner to it, the finger serving to hold the needle up to the looper should it
be inclined to press away from it, and to force the needle thread out on one side of
the needle as it is rising and thus form a good loop for the looper to enter.
Another feature of the improved mechanism is a device for converting the machine
into a single thread machine at pleasure without removing anything from the
machine. This is effected by means of a switch fixed to the underside of the
needle plate by a screw or stud having a hook at one end the other end
being so placed that the hook may be readily switched over the looper so as to
catch the loop of the needle thread when it is brought forward by the looper and
hold it in front of the needle until the needle enters the loop instead of allowing the
loop to be drawn back into the slot in the needle plate behind the needle as in
forming a double thread chain stitch. When the needle has thus entered the loop
of its own thread the loop is released at once and drawn up before a second loop
is formed by the needle.
In thus forming a single thred chain stitch it does not matter whether the looper
is threaded or not hence the machine can be converted while it is in rapid move-
ment from single to double and from double to single thread chain stitch with
the greatest ease and rapidity. It is however better to unthread the looper
when sewing in this way. This convertibility renders the machine suitable and

page_text: convenient for an immense variety of work including welting and seaming hosiery
fabrics embroidery and fancy stitching as well as plain sewing.
A further important feature of the improved mechanism is the facility with which
it can be arranged to make more than one line of single or double thread chain
stitching at the same time. For this purpose it is necessary only to add an extra
looper and an extra needle for each extra line of stitching required, to make so
many extra needle holes in the needle plate and so many extra hooks on the single
thread switch and also to place so many extra needle guards on the rock shaft all as
before described and any number of lines of sewing may be done at the one operation.
It is not necessary to fix an extra automatic tension or thread pull off or an extra
supplementary thread take up for each extra line of sewing all that is required being
to add sufficient thread guides and to otherwise arrange the details to conduct the
threads properly.
In combination with the improved mechanism hereinbefore described but also
applicable to other machines an improved trimming or cutting apparatus is or may
be provided a portion of which may be removed readily when the machine is not
required to trim or cut the fabric as it is being stitched and thus allow the machine
to be used for general purposes.
«
"
The said trimming or cutting apparatus consists of a trimmer bar fixed in
adjustable centres on the underside of the machine bed plate and actuated by means
of an extended arm and link connecting with a short crank on the said rock shaft,
the extreme end of this arm being made to lift the automatic tension. There is also
a short arm extending from the trimmer bar and carrying a roller and stud for moving
the feed upward and downward and these portions being underneath the bed plate
and employed to give motion as described to the feed and automatic tension they are
really incorporate parts of the machine but in some cases it will be advisable to con-
struct a feed bar with an extending arm so as to connect directly with the link and
crank on the rock shaft and thus obviate the use of this trimmer bar in machines not
required for trimming. A third arm to be known as the trimmer arm is attached
to the said bar by two screws so that it may be removable at will, the trimmer arm
rising up through and overhanging the bed plate carrying the cutting knife at its
extreme end. In order to adjust the distance of the knife from the needle sideways
one of the screw holes in the trimmer bar is made longer than the screw to allow the
arm to be radiated as desired or long slots may be made in the trimmer bar to enable
the arm to be moved bodily sidewards. The cutting knife acts in the same manner as
a firmer chisel coming down on to the needle plate with considerable force. The knife
is attached to the trimmer arın by a washer and screw and is fitted in a slide so that
it can be adjusted to give more or less pressure on the needle plate and the trimmer
arm rising up through the bed plate some distance behind the needle it does not
obstruct the passage of the fabric through the machine or prevent its being used for
cutting in from the edge or dividing the fabric as may be desired. It will be
observed that the trimmer bar gives upward and downward movement to the feed
and also serves to lift the automatic tension as well as to bring down the cutting
knife, which operations are arranged to take place alternately in order that the
trimmer bar having raised the feed and with it the presser foot in its upward move-
ment may receive the reacting pressure of the said foot to assist it on its return when
it is desired to bring down the cutting knife to lift the automatic tension, the
reacting pressure of the automatic tension on the said bar and of the cutting knife on
Thus
the needle plate again assisting the bar on its upward movement and so on.
each movement regains part of the force given out and ultimately conduces to the
light and steady running of the machine.
1
T
T
T1 1000
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.

page_text: 1, CORNELIUS MUNDY 28 College Avenue Leicester, Mechanic, 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 which has for its object improvements in sewing machines relates to
an improved double thread chain stitch sewing machine which can be converted at
pleasure into a single thread chain stitch machine and which is further capable of making
one or more lines of single or double thread chain stitching at the same time, the
said machine having an improved trimming or cutting apparatus in combination
with it but which apparatus may also be adapted to other sewing machines.
In the accompanying drawings which illustrate the invention figure is a sectional
elevation, figure 2 an inverted plan and figure 3 an end elevation of a modification of
the improved machine as provided with a single needle and figures 4, 5, 6, 7, 8, 9, 10
and 11 are enlarged views of details hereinafter referred to. Figures 12, 13 and 14
are views corresponding to figures 1, 2 and 3 of a modified form of the machine
adapted for simultaneously making a number of rows of stitches and figures 15, 16,
17 and 18 are views of details of said machine.
The machine is composed of the usual flat bed plate A with overhanging arm A¹
and is fitted with a rotary main driving shaft B provided with a balance wheel B¹
to which driving power is communicated the said shaft having a crank b which through
a connecting rod o¹ and other usual mechanism operates the parts of the machine
underneath the bed plate.
The improved stitch forming mechanism consists of a new or improved form of
looper C, separately shewn at figures 4 and 5, which is firmly fixed to a rock shaft D
which receives its motion direct from the main rotary shaft B through the medium of
a crank and connecting rod the rock shaft D moving only through a quarter of a
circle or thereabouts and in the same line as the feed. The looper C has the form of
a curved or circular hook arising from a central disc C¹ which is passed on to the end
of the rock shaft D and screwed to a solid disc, so that it becomes virtually a part of
the rock shaft and whilst it is adjustable at the screws in all directions when desired it
is not liable to that looseness in action which is invariably the result of a multiplicity
of parts and loose connections. The looper C though capable of being employed and
lending itself readily for the purpose of making a single thread chain stitch is
principally intended for making a double thread chain stitch and is thus required to
carry a separate thread which is conducted through several eyelets along grooved
channels c to the eye at its point. In order that the looper thread may be safely
controlled the looper is curved sideways as represented at figures 4 and 5 so that when
it takes the loop from the needle on the one side the loop is carried over to the other
side as the looper advances and also the looper thread along with it the looper on its
return drawing the two threads backward into a notch in a recess or slot cut in the
underside of the needle plate E as seen at figure 10 which is an inverted plan of said
plate and holding them there until the needle has descended. sufficiently to catch the
looper thread when the two threads are released and the stitch completed.
Another feature of the improved mechanism is a novel thread take-up device acting
upon the looper thread, and for which purpose the looper itself is partly available.

page_text: The looper thread being passed over thread guides e¹, e³, fixed to the under side of the
needle plate well in advance of the eye at the heel of the looper, when the looper
is brought forward as far as it will come the thread is merely passed from heel to
point and from point to heel of the looper according to its backward or forward
movement. The looper therefore supplies itself with slack thread and takes the
thread up again by this arrangement of the guides. The arrangement however does
not answer completely the requirements of a proper thread take up but renders it
necessary to deal with only a very small portion of the slack thread which otherwise
would have to be provided for by independent means. To supplement this take up
arrangement and render it thoroughly efficient and positive a quadrant or radial arm F
provided with a guide or eye f is employed which quadrant is a solid extension from
the central disc Č¹ of the looper on the opposite side to the hook or beak c¹ of the
looper and also opposite the thread guides e¹ e² on the needle plate. The quadrant
operates to take up the thread whilst describing an are in relation to the thread
guides e¹ the centre line of the arc being the point at which the quadrant takes up
most thread. The quadrant may be adjusted to arrive at this point at any degree of
the looper's movement that may be desired; and it is made in any suitable form which
will prevent the thread being caught by any projections from the centre disc. The
quadrant arm may also have a number of eyelets such as through any one of which
the thread may be passed in order to tighten it at any point of the looper's movement
which tightening is most required just when the needle is entering the looper thread.
Thongh fixed on the rock shaft D the quadrant F may be secured separately from the
looper and instead of passing the thread through eyelets the quadrant may be adjusted
as before mentioned to different positions by means of screws or other equivalents if
so desired. In using this take up the thread is brought over one guide e¹ on the
needle plate thence through the take up eyelet in conjunction with the guides and
then over the other guide e on to the eye c on the looper C.
Another feature of the improved mechanism is an automatic tension device and
thread pull off acting upon the looper thread so as to produce a superior elastic
stitch. The said automatic tension may be in the form of a flat spring H which
may be fixed at one end by means of a washer or spring and screws to the under
side of the bed plate; or it may be in the form of a lever H having its fulcrum fixed
in like manner and pressed by means of a flat or a coiled spring h while the other
end is lifted at the right time for releasing the thread either by means of a quadrant
fixed on the rock shaft or as shewn by a portion such as the lever N of the cutting
apparatus in combination with the machine and hereafter to be described. The pull
off may be in the form of a hook or a flat wing having a number of eyelets or
of a loop J as shewn and fixed to the looper rock shaft D by means of a screw
or a split bossj made to fit the shaft tightly. It can thus be adjusted to pull off
from the reel any desired quantity of thread as the rock shaft D moves forward and
on its return movement allow the same to be drawn through the lifted tension H
by the looper without any resistance except the friction of the guides e¹, ³, f, through
which it has to pass thus measuring at each repeated movement the quantity of thread
to be used or fixed in each stitch. Thread guides k, k³, are suitably placed to aid
in performing these operations.
To assist in guarding the upper needle and in forming a loop of the needle thread
a flat finger L is employed. The said finger has a central disc like the looper Cand
is fixed on the rock shatt D in a similar manner to it, the finger L serving to hold
the needle up to the looper should it be inclined to press away from it and to force
the needle thread out on one side of the needle as it is rising and thus form a good
loop for the looper to enter.
Another feature of the improved mechanism is a device for converting the machine
into a single thread machine at pleasure without removing anything from the machine.
This is effected by means of a switch M fixed to the underside of the needle plate
by a screw or stud M₁ the said switch having a hook m at one end as represented at
figures 8 and 9 the other end being so placed that the hook may be readily switched
over the looper C so as to catch the loop of the needle thread when it is brought

page_text: forward by the looper and hold it in front of the needle until the needle enters the
loop instead of allowing the loop to be drawn back into the slot at e in the needle
plate E behind the needle as in forming a double thread chain stitch. When the
needle has thus entered the loop of its own thread the loop is released at once and
drawn up before a second loop is formed by the needle.
In thus forming a single thread chain stitch it does not matter whether the looper
is threaded or not hence the machine can be converted whilst it is in rapid movement
from single to double and from double to single thread chain stitch with the greatest
ease and rapidity. It is however better to unthread the looper when sewing single
chain stitches in this way. This convertibility renders the machine suitable and con-
venient for an immense variety of work including welting and seaming hosiery
fabrics embroidery and fancy stitching as well as plain sewing.
A further important feature of the improved mechanism is the facility with which
it can be arranged to make more than one line of single or double thread chain
stitching at the same time. For this purpose it is necessary only to add an extra
looper and an extra needle for each extra line of stitching required, to make so many
extra needle holes in the needle plate and so many extra hooks m on the single thread
switch M and also to place so many extra needle guards L on the rock shaft all as
before described, or the needle guards may be dispensed with as shewn at figure 14;
and any number of lines of sewing may be done at the one operation. It is not
necessary to fix an extra automatic tension or thread pull off (J) or an extra supple-
mentary thread take up for each extra line of sewing all that is required being to add
sufficient thread guides and to otherwise arrange the details to conduct the threads
properly..
Figures 12 to 18 shew a machine as adapted for making five rows of stitches.
The loopers Care fixed or formed on bosses which are slipped over and adjustably
secured by screws or otherwise on the looper rock shaft D; and this mode of
securing the looper may also be adopted in all single needle or multiple needle machines.
In combination with the improved mechanism hereinbefore described but also
applicable to other machines an improved trimming or cutting apparatus is or may
be provided a portion of which may be removed readily when the machine is not
required to trim or cut the fabric as it is being stitched and thus allow the machine to
be used for general purposes.
The said trimming or cutting apparatus which is represented at figures 1, 2 and 3
consists of a trimmer bar N fitted in adjustable centres n on the underside of the
machine bed plate and actuated by means of an extended arm and link N' connecting
with a short crank on the rock shaft D), the extreme end of this arm at N' being
made to lift the automatic tension H. There is also a short arm N' extending from
the trimmer bar N and carrying a roller and stud n¹ for moving the feed bar O
upward and downward and these portions being underneath the bed plate and
employed to give motion as described to the feed and automatic tension they are
really incorporate parts of the machine; but in some cases as represented at
figures 12, 13 and 14 it will be advisable to construct a feed bar with an extending
arm O' so as to connect directly with the link N¹ and crank or eccentric on the rock
shaft and thus obviate the use of this trimmer bar in machines not required for
trimming. A third arm P to be known as "the trimmer arm" is attached to the
said bar N by two screws p, p' so that it may be removable at will, the trimmer
arm P rising up through and overhanging the bed plate carrying the cutting knife Q
at its extreme end. In order to adjust the distance of the knife Q from the needle
sideways one of the screw holes at p' in the trimmer bar is made longer than the
screw to allow the arm P to be radiated as desired; or long slots may be made in
the trimmer bar to enable the arm to be moved bodily sidewards. The cutting
knife acts in the same manner as a firmer chisel coming down on to the needle
plate E with considerable force, the needle plate being hardened or a hardened
piece R being laid on or let in to the said plate to resist penetration. The knife Q is
attached to the trimmer arm by a washer and screw q and is fitted in a slide Q₁ so
that it can be adjusted to give more or less pressure on the needle plate; and the

page_text: trimmer arm rising up through the bed plate some distance behind the needle it does
not obstruct the passage of the fabric through the machine or prevent its being
used for cutting in from the edge or dividing the fabric as may be desired. It will
be observed that the trimmer bar N gives upward and downward movement to the
feed and also serves to lift the automatic tension H as well as to bring down the
cutting knife Q, which operations are arranged to take place alternately in order
that the trimmer bar having raised the feed and with it the presser foot in its
upward movement may receive the reacting pressure of the said foot to assist it on
its return when it is required to bring down the cutting knife and to lift the automatic
tension, the reacting pressure of the automatic tension on the said bar and of the
cutting knife on the needle plate again assisting the bar on its upward movement
and so on.
Thus each movement regains part of the force given out and ultimately
conduces to the light and steady running of the 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. A sewing machine constructed and arranged to sew one or more rows of either
single or double thread chain stitches substantially as described with reference to the
annexed drawings.
2. In a sewing machine a looper co-operating with the needle to form stitches and
composed of a circular hook adjustably secured to a rock shaft and so curved sideways
towards its point as to carry the needle loop from one side to the other of the path of
the needle substantially as and for the purpose set forth.
3. The combination of the oscillating looper C with take up devices consisting of
the radial arm F provided with an eyelet or eyelets fand thread guides as e³ ³ on the
needle plate arranged to operate substantially as described.
4. The combination of the oscillating looper C the take up mechanism F, f, e', e²,
the automatic tension devices H, h, and the pull off J, j. arranged and operated sub-
stantially as described.
5. The combination with the looper C of the finger L, secured on the looper rock
shaft and adapted to hold the needle up to the looper substantially as described.
6. In a sewing machine the combination with a looper carrying or adapted to carry
an under thread, of a hooked switch co-operating with the looper and adapted to
hold the loop of the needle thread until the needle enters said loop and prevent the
engagement of the looper thread or to permit the needle to pass through the latter
whereby the machine is adapted to make either single or double thread chain stitches,
substantially as described.
7. In a sewing machine the combination with a needle bar carrying a number of
needles, of a number of loopers fitted on a rock shaft and co-operating with said
needles to form stitches and a switch provided with a number of hooks arranged to
operate as described whereby the machine may be adapted to sew any number of rows
of single or double chain stitches substantially as set forth.
8. In a sewing machine the combination of parts constituting the trimming
mechanism substantially as hereinbefore described with reference to the annexed
drawings.
9. In a sewing machine a lower thread tension device consisting of a spring or
lever automatically released at each stitch by an arm operated from the looper rock
shaft or from the trimming mechanism substantially as described.
11
L
SA11080
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.