IMPROVEMENTS IN " and SEWING MACHINES ADAPTED TO SEW AND TRIM THE EDGES OF FABRICS in
Year: 1885

page_text: the Edges of Fabrios.
I, WILLIAM FURMAN BEARDSLEE, manufacturer of Boston, Massachusetts, United
States do hereby declare the nature of my Invention for "IMPROVEMENTS IN
" and
SEWING MACHINES ADAPTED TO SEW AND TRIM THE EDGES OF FABRICS
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
My invention has for its object to provide a sewing machine adapted to sew and
trim the edges of a fabric or fabrics, the machine being especially adapted for
sewing knitted goods.
The sewing machine herein described in order that it may be run very rapidly
and sew soft material such as knitted goods without puckers or gathers has to be
and is provided with a peculiar tension or thread controlling mechanism for the
needle thread.
To enable the trimming mechanism, containing rotary cutters, to remain at rest,
or nearly so while the feed points are disengaged from the material and while the
needle is in the fabric, notwithstanding the said cutters are driven by gearing from
a continously rotatting shaft, I have provided the hook shaft of the machine with
a worm having a portion of each round of its thread substantially annular or
without pitch other parts of its thread having considerable pitch, the cutter being
rotated only when the portions of the threads of the worm which have pitch are in
engagement with the worm toothed gear on the shaft which, from the hook shaft,
rotates the main shaft of the trimming attachment.
In my present machine the feeding device is moved positively and rapidly and
its throw and the length of stitch is regulated by an adjustable cam or eccentric.on
the hook shaft, it being controlled by a screw in a screw holder fast on the hook
shaft.
Ahading m. immHATA

page_text: ".
The frame work A, overhanging arm A², having bearings for the needle-bar A²,
the needle A³, the vibrating lever A' to move the needle-bar, the hook shaft A³,
the hook A and the link A³ made at its lower end to surround an eccentric on the
hook shaft and joined with the lever A* back of its fulcrum A³, are all as usual in
chain stitch machines and not of my invention.
The trimming device" consists essentially of a frame B containing a diagonal
shaft B provided at its forward end with a disk-like cutter B which is presented
diagonally as shown to the fabric at the right hand side of the needle so as to trim
the fabric close to and parallel with the line of stitching, the face of the cutter B³
being concaved to prevent the nut at the lower end of the needle-bar from
striking it.
The diagonal shaft B¹ is provided back of its bearing with a spring B³, tho
tension of which is increased or diminished by a thumb nut B₁ screwed upon the
said shaft, the thumb nut being held by a set nut Bo.
The spring B³ acting against the nut B draws the shaft B¹ in the direction of
the arrow thereon Fig. 1, and causes the edge of the rotating cutting disk B to be
held in a yielding manner pressed against the edge of a second disk B which is
rotated in unison with the disk B³ their edges kept together by a force due to the
spring B³, passing each other and cutting the fabric placed between them, the
disk Be at such time supporting the fabric at one side of the usual throat-plate for
the needle.
The shaft B has fast on it the gear B' which is engaged by the gear B³ fast on
the shaft B, the latter having fast upon it a bevel gear B10 which is engaged by a
bevel gear B¹¹ fast on a diagonal shaft B13 provided with a worm-toothed gear B¹4
which is driven positively by means of the worm C fast on the hook shaft C³.
The shaft B, which I call the main shaft of the trimming attachment, is
provided with a second bevel gear B15 which engages a bevel gear B16 fast on and
rotates the vertical shaft B", to the lower end of which is secured the disk Bo
referred to, it being let into a recess in the top of the cloth-plate P, the surface
speed of the edge of the two disks being the same.
To fasten the frame work of the trimming mechanism securely in place, I have
provided an auxiliary frame D held in place by screws D' and D* in the sewing
machine frame and at opposite ends of the frame D, I have attached the frame B to
the frame D by a screw D³, and the lower end of the frame B is attached to a
lug D* on the frame A by a screw D, set screws D7 aiding in fine adjustments.
The worm C, shown as laid out flat in Fig. 6, has, it will be seen, some parts of
its threads as at c made substantially annular or without pitch, the remaining
portions o² of the threads having considerable pitch, the length of the annular
portions c', or portion without pitch, depending upon the period during each
rotation of the hook shaft which it is desired that the cutters B and B remain
at rest, the speed of rotation of the cutters depending upon the pitch of the
portions of the thread.
The feeding mechanism now .to be described, consists essentially of a bar E
having an attached toothed plate E and pivoted at E² to a rocker E³ pivoted on
a rock shaft E4, and a connecting link Es having at one end an eccentric strap to
embrace an adjustable eccentric or cam. E surrounding loosely and made adjustable
on a sleeve-like screw-holder E7 fast to the main shaft A³.
The forward end of the bar E is slotted to embrace the usual eccentric of the
sleeve at the rear side of the hook A6, the said eccentric raising and lowering the
bar E as usual.
The forward and backward movements of the bar. E are produced by the link E³,
which at one end surrounds the shaft E2 in the upper part of the rocker E³, the
said link deriving its movement from the eccentric E°.
The eccentric E, see Fig. 1, is provided with a threaded hole which receives the
screw Es provided with a squared or other shaped outer end to be engaged by a
wrench or tool by which to rotate the said screw, The inner end of the said
screw is shown as flanged and as fitting. loosely a seat in the interior of the screw

page_text: holder E' fast to the hook shaft by a screw E, the screw Es consequently rotating
loosely in the screw holder, but as it is so rotated it is held from longitudinal
movement and the result is the eccentric E" is moved on the screw holder and
transversely with relation to the center line of the hook shaft.
Supporting the rear end of the bar E on a rocker enables the said bar to be
carried positively backward and forward at its rear end without sliding friction as
would be the case if the outer end of the said bar was forked and slid on a stud,
and further the rocker prevents any side twist of the bar E.
The needle thread is held between the spool and needle-bar by a clamp one
member of which is acted upon by a spring thus causing the clamp to have
constant pressure, the clamp exerting at all times a certain definite but constant
pressure or tension, and acting at all times as a positive check to prevent any
backward movement of the thrond.
The normal pressure on the thread of the movable member of the thread clamp
is sufficient to exert such an amount of tension as is necessary for proper sewing
except when the needle-bar is at or near the upper portion of its stroke and the
hook is going into its lowest position and drawing out the greatest length of loop,
or just when the needle-bar and hook, coöperating together, are drawing up.the
loop of and completing or setting the previous stitch, and at such times as the
normal force of the thread-clamp is not sufficient to do good work I temporarily
augment the clamping pressure on the needle thread, and as herein shown
I have for such purpose employed a pressure adjusting device shown as a spring-
controlled lever which is made intermitting in its action, it being effective in
holding the needle thread only as the stitch is being set or completed as stated.
I have also provided the head of the machine with a thread holder, it acting to
hold the thread intermitting as will be described while the needle-bar is descending
to thus avoid slack thread near the eye of the needle, the said device being placed
diagonally and being made adjustable to facilitate the entrance and exit of the
needle thread at just the proper time.
The frame or bracket a upon which are mounted the devices constituting my
improved thread clamping mechanism, is shown as fastened to the frame A by a
screw a¹ The frame or bracket a has pivoted upon it at a³ the movable
member or lever a³ of the thread-clamp, the other member being shown as a rest a³,
made as a block pivoted at a³, on a slide or foot piece as, adjustably attached to
the plate a by a screw a7, the said plate a being herein shown as provided with
ribs between which is placed the said foot piece, the latter being slotted where the
screw a enters it.
The end of the movable clamping member a³ next the rest a is bevelled to act
upon the thread, and the said member is so pivoted and shaped as always to act as
a positive check to prevent any backward slipping or rendering of the thread
passing between it and the rest, the said movable member being normally held
pressed against the needle thread b by an adjustable spring b¹ shown best by dotted
lines Fig. 1, the said spring being shown as made from spring wire, a part of which
is wound to form a coil to embrace the stud or pin bª of the plate a, the end of the
spring b¹ opposite that acting on the movable member as being shaped to be acted
upon and be adjusted by an adjusting screw bs, the rotation of the said screw in or
out increasing or decreasing respectively the force of the spring 63 on the said
movable member a³.
This spring exerts its pressure constantly and is never so strong as to prevent
the needle-bar and hook when acting together from drawing from between the
clamp sufficient thread for the requirements of the stitch being made.
The needle thread taken from a suitable spool or bobbin is passed through guide
eyes 4 and 5, thence through the pull-off d, through an eye 8 in the long arm of
the movable member or lever a³, thence through a guide eye 9, over the saddle 10,
between the thread clamping member a³ and at, over saddle 12, again through the
thread guide 3, and between the disks of the tension device T in the usual manner,
if the latter be employed as is preferred, thence through the thread guide 3, and
La

page_text: the guide 13 carried by the needle-bar, and thence between the members of the
thread-holder to be described, and into the guide 2 and through the eye of the
needle.
Pivoted on the plate a at 14 is a pressure augmenting device e shown as an
elbow lever provided with a pin or projection 15 and acted upon by a spring 16.
From the foregoing it will be seen that the needle thread is clamped constantly
by a force measured by one spring, but that at certain times, as during the com-
pletion of the stitch, the clamping force on the needle thread is augmented by an
independent pressure augmenting device, and this is one of the chief features of my
Invention.
When both the said pressure augmenting device and the spring 6' produce
pressure upon the clamp, it is impossible for the hook alone to draw thread from
the spool except to accommodate for variations in thickness of the material, but
when the pressure augmenting device is not effective on the member a³, then the
pressure of the spring b¹ acts to hold the thread with a constant pressure but not
so strongly as to prevent the hook and needle-bar taking the needle thread and
drawing it through between the clamp sufficient for the formation of the stitch,
the pressure of the spring b¹ being constant and being regulated by the adjusting
screw 6³, according to the strength of the thread and the work being done.
The extent of the pressure exerted by the pressure augmenting device upon the
clamping member a³ is relieved at the proper time during the descent of the
needle-bar by means of the adjusting device or screw e¹ in the arm or finger e³
attached to or forming part of the needle actuating lever A, the release being
sooner or later according to the thickness of the material and the strength of the
thread so as to put on the extra pressure at any desired part of the upper stroke of
the needle-bar.
Prior to my invention I am not aware that the thread has ever been clamped by
a pressure determined by the force of one spring, and that such clamping pressure
has been thereafter augmented intermittingly thus increasing temporarily the
pressure on the thread passing to the needle.
As herein shown one of the said devices is a spring operating upon the movable
member or lever of a thread clamp, and the other device is a spring controlled
lever which also acts on the same movable lever or member of the clamp.
At the head of the machine is placed a needle thread-holder composed of a base f,
a spring ƒ³, and a spring protector g. The holder is held in an inclined position on
the head, as shown in Fig. 2, to facilitate the passage of the thread under and then
out from under the control of the spring f¹ as the needle-bar rises and then
descends.
The base plate is provided at its front with a recess f³ at the rear side of a teat ƒº¹
in which rest the spring f', and in this recess having a wedge-shaped or inclined
bottom is placed the needle thread. As the needle-bar rises and draws the needle
thread taut the latter moves to the left in the space f³ Fig. 7 and passes further
under the spring f¹ where it is left, and so caught it is held lightly while the
needle is passing through the first portion of its descent thus preventing the
formation of slack thread under the point of the needle, but as soon as the needle
enters the material being sewed the downward pull on the thread owing to the
diagonal or downward inclination of the spring f¹ quickly draws it from under
the spring into the notch f³ and the thread is left entirely free from any pressure
of the spring fi thereon.
The spring f¹ made widest at its inner end is connected with the base by a
screw 23. The spring protector g is attached in place by the screw g¹.
The pull-off & connected with the needle-bar actuating arm draws from the spool
or bobbin, not shown sufficient thread for each stitch leaving it loose at the rear
side of or behind the clamp. The clamp herein described is so shaped and its
parts are so pivoted as to positively prevent any backward movement of the
thread, but permitting the free forward travel of the thread whenever the pull
upon the thread is sufficient to overcome the pressure exerted thereon by the clamp

page_text: and it will also be seen whenever the thread is strained or drawn by the needle-bar
or the hook, that the said thread extended through the eye 8 in the long end of the
movable member of the clamp acts to close the clamp closer and closer thus
preventing any back rendering of the thread, and especially when the pull-off is
acting to take thread from the spool or bobbin.
I desire it to be understood that instead of putting the extra pressure on the
member A³ and by it on the thread, that as a modification I might place a block
near the long end of the member a³ and let the needle thread pass between the
said block and the upper end of the elbow lever e while on its way from the eye 8
to the eye 9.
"The presser-foot & secured to the presser-foot bar is cut away for the
cutter B to act upon and trim the goods near the needle-hole 19. The cloth
plate P has attached to it by a thumb nut H' a lifting plate EL, the beveled edge of
which enables the fabric to be gradually lifted to the plane of the cutter.
•
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. machine for stitching and trimming knitted goods, it containing a needle-
bar, a needle, a lever to move it, a rotating hook; a trimming mechanism composed
essentially of two rotating disks B³, Bº, and devices to rotate them; a thread
controlling mechanism consisting of a pull-off device d, clamping members a³, a^,
spring b, pressure augmenting device e and means to operate it and a feed bar E E',
and means to move it, substantially as described.
2. A thread controlling mechanism for sewing machines, it containing as
elements, a thread clamp composed of two members a³, a, between which the
thread is passed, one of the said members being made as a lever through which
the thread passes and acts when strain is put upon it thus turning the lever to
close the clamp upon the thread, and of a spring 6 to act upon one of the said
members to determine the degree of the constant pressure of the clamp upon
the thread, and of a pressure augmenting device e to effect the increase in the
clamping pressure upon the needle thread just while the stitch is being set or
completed, substantially as described.
3. In a sewing machine, the rotating hook shaft A5, a screw holder E thereon
the cam or eccentric E, the screw E to adjust the said cam or eccentric, the
link E, the rocker E3 and the feed-bar E E', to operate all substantially as
described.
4. The rotating shaft A³ and its attached worm provided with annular teeth c¹
and pitch teeth c³, the teeth of the said worm engaging teeth of a worm gear B¹
and rotating the shaft B¹³ at an intermitting or varying speed, substantially as
described.