IMPROVEMENTS IN SEWING MACHINES
Year: 1862

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the
County of Middlesex, Engineer and Patent Agent, for the Invention of
** IMPROVEMENTS IN SEWING MACHINES."-A communication from abroad
by Messrs. Dwight Tracey and George Hobbs, both of Worcester,
in the County of Worcester, and State of Massachusetts, United States
of America, Machinists.
Sealed the 6th April 1863, and dated the 23rd October 1862.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 23rd
October 1862.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SEWING MACHINES," to be as follows:-
This Invention consists in part of a novel mode of controlling the needle thread
of a sewing machine, whereby the quantity delivered to the needle is caused to.
be always in proportion to the thickness of the cloth or other material being
sewed and the length of the stitches to be made, and a uniform tightness of
stitch is produced whatever variation may occur in the thickness of the material,
or however the feed motion may be varied, obviating entirely the necessity of any
manual adjustment by the operator for sewing material of different thickness.
It also consists in an improved mode of applying the locking thread, spool,
or bobbin in combination with the rotating hook of what is known as the
"rotating hook sewing machine," whereby a much larger bobbin or spool can
A

page_text: be used than by the modes of construction heretofore adopted. Also in a
loop check of novel construction operating to check the loops of the needle
thread in their passage over the rotating hook without aid from any other part
of the machine, and serving also to hold in position a spool case which
contains the locking thread. Also in certain improvements in the feeding
device, whereby it is better adapted to the feeding of work of varying
thickness, and made to work with little noise. And it further consists in
certain improvements in the construction of the thread spools for containing or
carrying the thread used or to be used in sewing machines, whereby they
are made to occupy very little room and to contain a large quantity of thread
in a very small compass, one object of this improvement being to have the
thread spooled by the manufacturer in a form suitable for use as the locking or
lower thread in the rotating hook sewing machine without the necessity of
re-winding or re-spooling.
The several improvements, as also the construction of the thread spools, are
illustrated in the accompanying Drawings, in which Fig. 1 is a right-hand
side view of a rotating hook sewing machine having the improvements
applied; Fig. 2 is a diagram illustrative of the action of the needle in drawing
the thread from the upper spool; Fig. 3 is a front view of the machine
with the framing and work plate in section; Fig. 4 shows the rim of the
spool case which contains the locking thread spool projected on a plane; Figs. 5
& 6 are different views of the rotating hook; Figs. 7, 8, & 9, are different
views of the locking thread spool case; Fig. 10 is a top view of the loop
check; Fig. 11 is a face view of the rotating hook, spool case, and loop
check; Fig. 12 is a longitudinal vertical sectional view of the feed bar and
dog and their appendages; Fig. 13 is a top view of the dog detached from
the feed bar. Similar letters and numbers of reference indicate corresponding
parts in the several Figures.
A is the frame of the machine; B, the work plate; C, the main shaft
carrying the rotating hook D; E, the needle arm; P, the presser arm; and P¹
the presser, all with the exception of the rotating hook D constructed in the
manner common to what is known as the "Wheeler and Wilson" sewing
machine. F is the spool which supplies thread to the needle n, arranged upon
a double elliptic spring G, which is fitted at its ends to turn upon a stationary
spindle a, secured in the framing A, as shown.. The needle thread shown in
red color is conveyed from the spool through a forked arm H, attached to
and vibrating with the needle arm, and from this arm through a spring friction
clamp I, J, attached to the needle arm thence through a positive, but
intermittent acting gripper K, L, also attached to the needle arm, and thence

page_text: through the usual guide d at the end of the needle arm to the eye of the
needle n. The part I of the friction clamp I, J, and the part K of the
gripper K, L, are portions of the same plate attached rigidly to the needle
arm. The movable portion J of the friction clamp is placed on a small
pin d, and has applied to it to produce the necessary pressure. a spring e
secured to the plate I, K, by the screw e¹. The object of this clamp is to
keep a gentle tension on the thread between the gripper and the spool when
the gripper is open. The movable portion L of the gripper constitutes a
portion of a lever L, L', whose fulcrum is a knife edge formed on the plate
K, and it is kept closed upon the thread during nearly three-fourths of every
revolution of the rotating hook by means of a conical volute spring g applied
with its centre exactly opposite to where the thread passes through the
gripper but during the remainder of the revolution commencing soon after
the needle enters the cloth, the gripper is open to permit the delivery of
thread to the needle. The object of the gripper is to hold the thread
securely to prevent positively any delivery of thread from the spool at
the time of tightening each stitch. The lever L constituting the movable
jaw of the gripper is confined to its fulcrum by a slight projection on
the plate K. The said lever is acted upon to open the gripper by
means of an arm i rigidly attached to the rod M', which transmits motion
from the eccentric M on the main shaft to the rocker E, which carries
the needle arm, the opening being effected by the lever and arm being moved
towards each other by the relative movements of the rod M' and the rocker E,
and the closing being effected by the spring g as the movements of the said
5 rod and rocker are continued. The forked arm H renders the operating
portion of the needle thread at all times independent of the spool F, by keeping
a quantity of thread greater than required for the longest stitches liberated or
drawn off from the spool in advance of its being required for use. .The
liberation or drawing off the thread from the spool is effected by the descent of
the said forked arm as the needle bar rises, the gripper K,L, having at the time
a firm hold upon the thread, so that any ineqularity in the friction of the spool
or in the delivery of the thread, owing to entanglement or other cause, cannot
affect the uniform tightening of the stitch. By thus keeping a portion of the
thread liberated in advance, the thread is enabled to be used from a ball or
5 skein as well as from a spool, by which means a great saving may be effected
in large manufacturing operations owing to the lower cost of thread in balls
and skeins. The rotating hook D, of which Fig. 5 is a side view, and Fig. 6
a central section in the plane indicated by the line x, x, in Fig. 5, differs in
some particulars from those heretofore used, in order to adapt it to the work in

page_text: combination with the spool case N, and to so control the loop of needle
thread below the table as to assist in delivering the proper measured quantity
of thread to the needle required to make each stitch, as will be herein-after
described.
The spool case N, of which Fig. 7 is an outer face view, Fig. 8 a side
view, and Fig. 9 an axial section, consists of a circular box deep enough to
contain a spool S, which is large enough to hold two hundred yards of the
coarsest thread commonly used in sewing machines. This case has a hinged
cover or door N¹ in its outer side to permit the introduction and removal of
the spool, and it has a fixed central spindle N2 attached to its back for the
reception of the spool, such spindle being made hollow to make the case as
light as possible. p is the hinge of the door N₁, which closes with a snap.
The said case is set in the hook in an oblique position, its front part being the
most prominent, as shown, such oblique position being maintained by its being
furnished with an oblique flange or shoulder m, which extends all around
except opposite to the work plate B, where it is omitted for a short distance,
as shown at m² in the projection Fig. 4, and the said flange or shoulder resting
against the annular seat m¹ provided for it in the rotating hook, the said seat
being parallel with the planes of revolution of the said hook. The case is
held up to the rotating hook by a guard finger Q, which is arranged to swing
aside on a fixed pin q to permit the spool case to be taken from or inserted in
the hook, which can only be done while the tongue k on the case is opposite
to the opening between the point and heel of the hook. The bearing surfaces
of the finger Q consist of springs 9, 92, which hold the case securely against
the seat in the hook in such manner as to prevent rattling, but yet permit the
loops to slip freely off the outer faces of the case, and prevent the thread from
being checked unevenly by any movement of the case from the hook. The
oblique arrangement of the case is partly to permit the needle to pass it and
partly to enable the thread to be easily thrown around it, which, owing to its
great thickness, would otherwise be difficult, and the prominent part that
receives the loop as it is cast from the hook just as the stitch is tightened
keeps the loop extended, thus preventing the thread from curling around the
point of the needle in sewing thin goods. The front of the case is so cut
away as to form an opening r, s, the object of so cutting it away being twofold,
viz., to allow the thread to freely leave the loop check R, which will be
presently described, and to form a shoulder r, against which the said check
acts as a stop to prevent the rotation of the case with the hook in the operation
of the machine. At a short distance in front of the shoulder r there is
formed on the case a projection t, to which the check serves as a stop to

page_text: prevent the case from turning in the opposite direction to that above mentioned.
The tongue k before mentioned, having its point 12 not far from the needle,
catches the thread of the loop soon after the commencement of its extension by
the rotating hook, and by preventing it from being drawn around the periphery
of the spool case causes one side of it to be turned over the back of said case.
The purpose of the
groove in the rotating hook is to enable the point 13 always
to catch the loop of the needle thread as it is carried forward by the rotation
of the hook. The locking thread, shown in blue color, leaves the spool case
through an opening 14 in the top, and in order to prevent its being drawn out
too easily it has applied to press upon it outside of the said bole a spring u, in
which is a notch 15 to guide it to the needle hole in the work plate. The
loop check R is made of steel or other metal, and as before described is
stationary in front of the shoulder r of the spool case. Its upper or operating
part 13, viewed looking toward the side of the rotating hook and spool case, as
in Fig. 1 is of a slightly hooked form, but so rounded as to present no angles
that would hold the thread, so that it could not be drawn off by a pull in a
more or less upward direction after having been released from the hook. The
said part 13 viewed from the top, as shown in Fig. 10, which is a top view of
the loop check, has an oblique surface, so that while the thread is placed
across it and partly around it, or kept stretched tightly against it, as shown in
Fig. 10 in red outline, the said thread cannot be drawn from under it by an
upward pull, but when the thread is not thus held closely around or across it,
an upward pull will draw it off easily. The lower part of the loop in being
drawn over the spool case by an operation, substantially the same as that in
other rotating book sewing machines, arrives at the shoulder and slips off it
and under the loop check, as shown in Figs. 1 and 3, and the rotating hook
has then drawn the part of the loop which passes behind the case, which .I
will term the back part, to such a position that the portion of the thread
under the check will have the direction shown in Fig. 10, and so be held
by the check alone, and the rotating hook will continue to give this direction
to the back part of the loop until the loop has been entirely thrown off it.
This loop check is secured to the framing of the machine by means of the
screw q, on which the finger Q works, and it is grooved to fit a tongue q* on
the framing, and has a slot q3 for the passage of the screw q to provide for its
adjustment in a direction concentric to the axis of the rotating hook and spool
case, the object of such adjustment being to bring it further or not so far
under the spool case to make it act earlier or later in the descent of the
needle, and thus cause a greater or less quantity of the needle thread to be
taken from its spool F, the said check acting in combination with the needle

page_text: to effect and regulate the supply of its thread from the said spool, and con-
stituting what may be termed an independent thread-supplying device, by
reason of its operating to supply thread from the spool to the needle with an
action entirely independent of the means by which the tightening of the stitch is
effected. The said check has fitted to a mortise in its point a light spring r,
which projects very slightly from it, but is kept within the check by the
pressure of the shoulder r against it in the running of the machine until the
thread of the loop commences to pass between the said shoulder and the
check, when it aids the thread to pass back the said shoulder far enough to
let it pass, but continues to detain the thread momentarily after it has passed
the solid portion of the check, and hence it makes the liberation of the thread
from the check easier and more gradual. Although the loop check is shown
applied in combination with a spool case, yet it may be usefully employed in
machines in which the spool case is not used, as is the case in the Wheeler
and Wilson machine before referred to, in which case the position and form
of the same would be altered to adopt it to the hook and bobbin used in such
machines. The combined operation of the rotating hook, spool case, thread-
controlling apparatus, and loop check is as follows:-Just as the eye of the
needle is descending through the cloth, and as the loop last formed and upon
the hook is approaching very near to the check, as shown in Fig. 1, the hook
by its continued rotation draws the loop over the shoulder r and under. the
check R, which detains the loop, so that it will be tightly drawn around the
hook and spool case before the needle has completed its descent, after which
the necessary amount of thread to allow the needle to complete its downward
movement is drawn from the spool through the open gripper. This quantity
is the amount necessary to form a perfect stitch. The check then continues
to detain the loop until the latter has escaped from the point of the rotating
hook, and commences to be drawn up by the ascent of the needle. The
tightening of the stitch is effected in the usual manner by the combined
action of the continued rise of the needle and the continued rotation of the
hook, except in sewing thick goods, when it receives an additional strain just
before the loop is turned off the point of the hook by the check. As the
needle is completing its upward movement, the forked arm. H by its descent
draws off thread from the spool F. In this action of the fork H its move-
ment is sufficient to draw off more thread than is necessary to make a stitch.
The quantity of thread drawn through the gripper by the needle in its descent
is guaged by the thickness of the cloth and the length of feed; .and as it is
desirable to have the upper and lower threads interlace in the middle of the
cloth, the difference in the quantity required by the needle for various thick-

page_text: nesses is equal to the difference of thickness, but the action of the needle
unless it were corrected by the action of, the hook and check, as will be
presently explained, would be to make the difference equal to twice that
amount. This action is caused by the unfinished stitch and the location of
the slack thread on the opposite side of the work to that from which the
needle thread is supplied, as will now be explained by the aid of Fig. 14.
When the eye of the needle reaches the cloth at 30, the loop 22 below the
table will be shortened by the thickness of the cloth, shown at 21, and when
it has descended through the cloth the loop will be shortened again by the
thickness of the cloth, as shown at 20. If the length of loop below the table
was the same in sewing thick as in sewing thin goods, the quantity of thread
drawn from the spool would be such that the under or, locking thread would
be just drawn to the under side. The needle cannot commence drawing
thread from the spool until it has drawn the loop below the cloth tight around
the check, spool case, and hook, on account of the friction produced on the
thread by the friction clamp J being greater than the friction on the thread
passing through the cloth at 21, hence by causing the length of loop to be
decreased as the cloth increases in. thickness, the amount of the decrease will
be free to be drawn up by the needle, which will correspondingly delay the
commencement of drawing from the spool, and decrease the quantity taken.
This is effected partly by the position of the shoulder of the hook and the
check at the time of commencing to draw thread from the spool, and partly
by the shape of the heel or tail of the hook over which the thread rests
during the drawing of the thread. This is illustrated by Figs. 1 and 11, both
of which show the position of the parts at the time of commencing to take the
thread from the spool. Fig. 1 shows the positions with thick goods, and 11
with thin goods. .It will be seen in Fig. 11 the rotating hook has passed
much further, and the loop is much longer, its thread being in a tortuous
position, the part passing over the heel resting on the fullest part l. In Fig. 1
the hook is much less advanced, and the thread on the heel is on the lowest
part, which produces the necessary shortening of the loop for the aforesaid
.correction. The length of the loop may be decreased to the desired extent by
I cutting out the heel at 1'.
· The improvement in the feeding device is best illustrated in Fig. 12, in
which, and in Figure 3; T represents the feed bar applied under the work plate
in the manner common to what is known as the "four-motion" feed, and
having the toothed dog U connected with it by a spring V,-to permit the-
upward and downward movement to bite, and release the cloth, but the dog
instead of being rigidly attached to the spring, as is usually the case, is

page_text: arranged to rock in such manner as to adapt itself to any increase or
diminution of thickness of the work, either sudden or gradual. The said dog
is made of a separate piece of steel, with a curved or rounded bottom, and a
conical cavity in the said bottom for the reception of the pointed end of an
adjusting screw w, screwed through a block of metal V₁, which is rivetted or
otherwise secured to the spring V. Portions 18 of the spring are extended
beyond its connection with the said block to press upon the flat upper surfaces
of shoulders y, y, Fig. 13, provided on the sides of the dog near the middle of
its length, and so keep the dog on the point of the screw on which it is free to
rock to accommodate itself to the varying thickness of the work. The vertical
movement of the feeding bar V to cause the dog U to engage with the cloth
' is imparted by an incline on the periphery of the cam W acting against the
bottom of block V, and the longitudinal movement of the said bar is produced
by the broad inclined face of the said cam against the contact surface y of the
lever Y, shown partly in dotted lines in Fig. 3, which lever acts upon the feed
bar, and throws it forward in the direction that the teeth of the feed dog U
are inclined. The movement of the system in the opposite direction is
produced by the spring T. The face of the cam W, which acts upon the
lever Y, is made with its incline of sufficient elevation at the periphery to give
the feeding dog an extent of motion in the direction of the seam sufficient for
the longest stitch required to be made, and in the inner part next to the shaft
of an elevation sufficient for the shortest stitch desired to be made, and the
surface in a radial direction inclined from one to the other. The lever Y is
mounted upon. an axis Z, which is made to slide longitudinally in bearings in
the frame A transversely to the shaft C, so as to present the contact surface y
to that part of the cam W which will impart just the extent of motion to the
feed dog U that will give the desired length to the stitches. The advantage in
employing such a cam to actuate the feed bar is that the contact surface y of
the lever Y bears constantly upon it whatever may be the length of stitch
to be made, so that the movements of the feeding mechanism are noiseless
and without abruptness in any part, however fast the machine may be run.
The improvements in the thread spools are illustrated in the Drawing, in
which Fig. 15 is an end view, Fig. 16 a side view, and Fig. 17 an axial
section, of one of the improved spools; Figs. 18, 19, 20, and 21 illustrate its
construction; Figs. 22, 23, and 24 are axial sections of three differently
constructed spools; Fig. 25 is a side view corresponding with Fig. 24; Fig. 26
illustrates the construction of the heads of the spools represented by
Figs. 22, 23, 24, and 25. Similar letters of reference indicate corresponding
parts wherever they occur in these Figures.

page_text: The spool shown in Figs. 15, 16, 17 is composed of a thin tube A of metal
forming the body, and two discs B, B, of cardboard or thin metal forming the
heads. The tube A is formed of a piece of sheet metal, Fig. 18, which has
two ridges a, a, formed in one side by creasing or indenting the opposite side,
as shown at b, b, in Fig. 19, and is then rolled up to form the tube shown in
Figs. 20 and 21, the ridges a, a, then forming flanges all around the tube.
The two heads B, B, have holes made in their centres to fit the ends of the
tube, and after having been placed thereon up to the flanges a, a, are secured
by turning over the ends of the tube in an outward direction, as shown at c, c,
in Fig. 17.
The spool shown in Fig. 22 is formed by taking two discs C, C, of cardboard
or thin sheet metal, and making a series of cuts extending equal distances
across the centre, as shown at d, d, in Fig. 26, thus forming a series of V-shaped
parts e, e, which are then to be turned out at right angles to the planes of the
discs, and such parts e, e, of the one disc are inserted within the corresponding
parts of the other, as shown in Fig. 22, and secured by gumming, pasting,
glueing, or soldering to form the body of the spool.
The spool shown in Fig. 23 is composed of two discs C, C, like that repre-
'sented in Fig. 26, and a tube D, the portions e, e, of the said discs being
inserted within the interior of the tube, and secured by glueing, gumming,
pasting, or soldering.
The spool shown in Figs. 24 and 25 is made of two discs C, C, having a
tube E inserted within their portions e, e. If the tube E be of cardboard, it
may be secured by glueing, gumming, or pasting, but if of metal it may be
secured by turning over its edge in an outward direction upon the outer faces
I of the discs, as shown at f,f, in Fig. 24.
When the spools are to be filled they are placed in or upon a holder which
grasps and gives firm support to the heads, keeping them in place until the
filling has been completed, and the spool is taken out. When the supports
are moved the heads present but little resistance, and yield to the pressure of
the thread, which has been stretched in winding, and the thread is thus
permitted to contract to its original length, thus preserving unimpaired its
elasticity. This quality makes these spools much superior to the rigid spools
commonly used for thread, which preserve the tension unavoidably produced
in winding, and so destroy the elasticity which it is very desirable to preserve
for the sake of making an elastic and durable seam. These spools can be
made cheaper than the wooden spools upon which sewing thread is ordinarily
sold, and hence they can be used with advantage by the thread manufacturer,
while their extreme lightness and small bulk renders them applicable, when

page_text: made of proper shape, for carrying the under thread of sewing machines
making a lock stitch, and so they enable the thread to be sold in condition for
use in such machines without rewinding, which consumes a considerable portion
of the operator's time. The spool S carrying the under thread in the machine
represented in the accompanying Drawings is of this kind, as also the spool F
carrying the upper thread.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
23rd April 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of October, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign did, for Herself, Her heirs and successors, give and grant unto me, the said
William Clark, Her special licence that I, the said William Clark, my exe-
cutors, administrators, and assigns, or such others as I, the said William Clark,
my executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SEWING
MACHINES,' a communication to me from abroad by Messrs. Dwight Tracy
and George Hobbs, both of Worcester, in the County of Worcester,
and State of Massachusetts, United States of America, Machinists, upon the
condition (amongst others) that I, the said William Clark, my executors
or administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said William Clark, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following

page_text: statement, reference being had to the Sheets of Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
:-
This Invention consists in part of a novel mode of controlling the needle
thread of the sewing machine, whereby the quantity delivered to the needle is
caused to be always in proportion to the thickness of the cloth or other material
being sewed and the length of the stitches to be made, and a uniform tightness
of stitch is produced whatever variation may occur in the thickness of the
material, or however the feed motion may be varied, obviating entirely the
necessity of any manual adjustment by the operator for sewing material of
different thickness. It also consists in an improved mode of apply the locking
thread, spool, or bobbin in combination with the rotating hook of what is
known as the "rotating hook sewing machine," whereby a much larger
bobbin or spool can be used than by the modes of construction heretofore
adopted. Also in a loop check of novel construction. operating to check the
loops of the needle thread in their passage over the rotating hook without aid
from any other part of the machine, and serving also to hold in position a
spool case which contains the locking thread. Also in certain improvements
in the feeding device, whereby it is better adapted to the feeding of work of
varying thickness, and made to work with little noise. And it further consists
in certain improvements in the construction of the thread spools for containing
or carrying the threads used or to be used in sewing machines, whereby they
are made to occupy very little room and to contain a large quantity of thread
in a very small compass, one object of this improvement being to have the
thread spooled by the manufacturer in a form suitable for use as the locking
or lower thread in the rotating hook sewing machine without the necessity
of re-winding or re-spooling.
The several improvements, with the exception of the construction of the
thread spools, are illustrated in Sheet 1 of the accompanying Drawings, in
which Fig. 1 is a right-hand side view of a rotating hook sewing machine
having the improvements applied; Fig. 2 is a top view of the same, with part
of the work plate, the presser, and the needle arm broken away to show the
parts beneath them; Fig. 3 is a front view of the same with the framing and
work plate in section; Fig. 4 shows the rim of the spool case which contains
the locking thread spool projected on a plane; Figs. 5 and 6 are different
5 views of the rotating hook; Figs. 7 and.8 and 9 are different views of the
locking thread spool case; Fig. 10 is a top view of the loop check; Fig. 11 is
a face view of the rotating hook, spool case, and loop check; Fig. 12 is a longi-
tudinal vertical sectional view of the feed bar and dog and their appendages;
Fig. 13 is a top view of the dog detached from the feed bar; Fig. 14 is a

page_text: Diagram illustrative of the action of the needle in drawing the thread from the
upper spool. Similar letters and numbers of reference indicate corresponding
parts in the several Figures.
The
A is the frame of the machine; B, the work plate; C, the main shaft
carrying the rotating hook. D; E, the needle arm; P, the presser arm; and
P₁, the presser, all with the exception of the rotating hook D constructed in
the manner common to what is known as the "Wheeler and Wilson sewing
machine." F is the spool which supplies thread to the needle n, arranged upon
a double elliptic spring G, which is fitted at its ends to turn upon a stationary
spindle a, secured in the framing A, as shown. The needle thread shown in
red color is conveyed from the spool through a forked arm H, attached to and
vibrating with the needle arm, and from this arm through a spring friction
clamp I, J, attached to the needle arm, thence through a positively but inter-
mittently acting gripper K, L, also attached to the needle arm, and thence
through the usual guide d.at the end of the needle arm to the edge of the
needle n. The part I of the friction clamp I, J, and the part K of the griper
K, L, are portions of the same plate attached rigidly to the needle arm.
movable position J of the friction clamp is placed on a small pin d, and has
applied to it to produce the necessary pressure a spring e, secured to the plate
I, K, by a screw e¹. The object of this clamp is to keep a gentle tension on
the thread between the griper and the spool when the griper is open. The
movable portion L of the griper constitutes a partion of a lever L', L', whose
fulcrum is a knife edge f formed on the plate K, and it is kept closed upon
the thread during nearly three-fourths of every revolution of the rotating hook
by means of a conical volute spring g applied with its centre exactly opposite
to where the thread passes through the griper, but during the remainder of the
revolution, commencing soon after the needle enters the cloth, the griper is
open to permit the delivery of thread to the needle. To object of the griper
is to hold the thread securely to prevent positively any delivery of thread from
the spool at the time of tightening each stitch. The lever L constituting the
movable jaw of the griper is confined to its fulcrum f by a slight projection /
on the plate K. The said lever is acted upon to open the griper by means of an
arm i, rigidly attached to the rod M', which transmits motion from the eccen-
tric M on the main shaft of the rocker E', which carries the needle arm, the
opening being effected by the lever and arm being moved towards each other
by the relative movements of the rod M' and the rocker E¹, and the closing
being effected by the spring 9, as the movements of the said rod and rocker
are continued. The forked arm H renders the operating portion of the needle
thread at all times independent of the spool F, by keeping a quantity of thread

page_text: greater than required for the longest stitches liberated or drawn off from the
spool in advance of its being required for use. The liberation or drawing off
the thread from the spool is effected by the descent of the said forked lever as
the needle bar rises, the griper K, having at the time a firm hold upon the
thread, so that any irregularity in the friction of the spool or in the delivery
of the thread, owing to entanglement or other cause, cannot affect the
uniform tightening of the stitch. By thus keeping a portion of the thread
liberated in advance, the thread is enabled to be used from a ball or skein
as well as from a spool, by which means a great saving may be effected
in large manufacturing operations 'owing to the lower cost of thread in balls
and skeins. The rotating hook D, of which Fig. 5 is a side view, and Fig. 6 a
central section in the plane indicated by the line x, x, in Fig. 5, differs in some
particulars from those heretofore used, in order to adapt it to the work in com-
bination with the spool case N, and to so control the loop of the needle thread
below the table as to assist in delivering the proper measured quantity of thread
to the needle required to make each stitch, as will be berein-after-described.
The spool case N, of which Fig. 7 is an outer face view, Fig. 8 a side
view, and Fig. 9 an axial section, consists of a circular box deep enough
to contain a spool S, which is large enough to hold two hundred yards of
the coarsest thread commonly used in sewing machines. This case has a
binged cover or door N' in its outer side to permit the introduction and
removal of the spool, and it has a fixed central spindle N2 attached.to its back
for the reception of the spool, such spindle being made hollow to make the
case as light as possible. p is the hinge of the door N', which closes with a
snap. The said case is set in the hook in an oblique position, its front part
being the most prominent, as shown in Fig. 2, such oblique position being
maintained by being furnished with an oblique flange or shoulder m, which
extends all around, except opposite to the work plate B, where it is omitted
for a short distance, as shown at m* in the projection,. Fig. 4, and the said
flange or shoulder resting against the annular seat m¹ provided for it in the
rotating hook, the said seat being parallel with the planes of revolution of the
said hook. The case is held up to the rotating hook by a guard finger Q;
which is arranged to swing aside on a fixed pin q to permit the spool case to
be taken from or inserted in the hook, which can only be done while the
tongue k, before described, on the case is opposite to the opening between
the point and the heel of the hook. The bearing surfaces of the finger Q
consist of springs q', 9, which hold the case securely against the seat in the
book in such manner as to prevent rattling, but yet permit the loops to slip
freely off the outer faces of the case, and prevent the thread from being

page_text: checked unevenly by any movement of the case from the hook. The oblique
arrangement of the case is partly to permit the needle to pass it, and partly to
enable the thread to be easily thrown around it, which, owing to its great
thickness, would otherwise be difficult, and the prominent part which receives
the loop as it is cast from the hook just as the stitch is tightened keeps the
loop extended, thus preventing the thread from curling around the point of
the needle in sewing thin goods. The front of the case is so cut away as to
form an opening r, s, the object of so cutting it away being twofold (viz.)
to allow the thread to freely leave the loop check R, which will be presently
described, and to form a shoulder r, against which the said check acts as a
stop to prevent the rotation of the case with the hook in the operation of the
machine. At a short distance in front of the shoulder r there is formed on
the case a projection t, to which the check serves as a stop to prevent the case
from turning in the opposite direction to that above mentioned. The tongue k
before mentioned; having its point 12 not far from the needle, catches the
thread of the loop soon after the commencement of its extension by the
rotating hook, and by preventing it from being drawn around the periphery of
the spool case causes one side of it to be turned over the back of the said case.
The purpose of the groove k¹ in the rotating hook is to enable the point 13
always to catch the loop of the needle thread as it is carried forward by the
rotation of the hook. The locking thread, shown in blue color, leaves the
spool case through an opening 14 in the top, and in order to prevent its being
drawn out too easily it has applied to press upon it outside of the said hole
a spring u, in which is a notch 15 to guide it to the needle hole in the work
plate. The loop check R is made of steel or other metal, and, as before
described, is stationary in front of the shoulder r of the spool case.
Its upper
or operating part 13, viewed looking towards the side of the rotating hook
and spool case, as in- Fig. 1, is of a slightly hooked form, but so rounded as
to present no angles that would hold the thread, so that it could not be drawn
off by a pull in a more or less upward direction after having been released
from the hook. The said part 13 viewed from the top, as shown in Fig. 10,
which is a top view of the loop check, has an oblique surface, so that while
the thread is placed across it and partly around it, or kept stretched tightly
against it, as shown in Fig. 10 in red outline, the said thread cannot be drawn
from under it by an upward pull, but when the thread is not thus held closely
around or across it, an upward pull will draw it off easily. The lower part of
the loop in being drawn over the spool case by an operation, substantially the
same as that in other rotating hook sewing machines, arrives at the shoulder r
and slips off it and under the loop check, as shown in Figs. 1 and 3, and the

page_text: rotating hook has. then drawn the part of the loop which passes behind the
case, which I will term the back part, to such a position that the portion
of the thread .under the check will have the direction shown in Fig. 10, and
so be held by the check alone, and the rotating hook will continue to give this.
direction to the back part of the loop until the loop has been entirely thrown:
off it. This loop check is secured to the framing of the machine by means,
of the screw' q, on which the finger works, and it is grooved to fit a.
tongue q on the framing, and has a slot q³ for the passage of the screw q to.
provide for its adjustment in a direction concentric to the, axis of the rotating,
hook and spool case, the object of such adjustment being to bring it further,
or not. so far. under the spool case to make it act earlier or later in the
descent of the needle, and thus cause a greater or less quantity of the needle,
thread to be taken from its spool F, the said check acting in combination
with the needle to effect and regulate the supply of its thread from the,
said. spool, and constituting what may be termed an independent thread-,
supplying device by reason of its operating to supply thread from the spool:
to the needle with an action entirely independent of the means by which
the tightening of the stitch is effected. The said check has fitted to a mortise
in its point à light spring r, which projects very slightly from it, but is
kept within the check by the pressure of the shoulder r against it. in
the running of the machine until the thread of the loop commences to.
pass. between the said shoulder and the check, when it aids the thread to:
press back the said shoulder far enough to let it pass, but continues to:
detain the thread momentarily after it has passed the solid portion of the,
check, and hence it makes the liberation of the thread from the check,
easier and more gradual.. Although the loop check is shown applied in com-:
bination with a spool case, yet it may be usefully employed in machines in,
which the spool case is not used, as is the case in the Wheeler and Wilson.
machine before referred to, in which case the position and form of the same.
would be altered to adopt it to the hook and bobbin used. in such machines.
The combined operation of the rotating hook, spool case; thread-controlling.
apparatus, and loop check is as follows:-Just, as the eye of the needle is.
descending through the cloth, and as the loop last formed and upon the hook,
is approaching very near to the check, as shown in Fig. 1, the hook by its
continued rotation draws the loop over the shoulder r and under the check R,,
which detains the loop, so that it will be tightly drawn around the hook and
spool case before the needle has completed its descent, after which the,
necessary amount of thread to allow the needle to complete its downward.

page_text: movement is drawn from the spool through the open griper. This quantity is
the amount necessary to form a perfect stitch. The check then continues to
detain the loop until the latter has escaped from the point of the rotating
hook, and commences to be drawn up by the ascent of the needle. The
tightening of the stitch is effected in the usual manner by the combined action
of the continued rise of the needle and the continued rotation of the hook,
except in sewing thick goods, when it receives an additional strain just before
the loop is turned off the point of the hook by the check. As the needle is
completing its upward movement, the forked arm I by its descent draws off
thread from the spool F. In this action of the fork H its movement is
sufficient to draw off more thread than is necessary to make a stitch. The
quantity of thread drawn through the gripper by the needle in its descent is
guaged by the thickness of the cloth and the length of feed; and as it is
desirable to have the upper and lower threads interlace in the middle of the
cloth, the difference in the quantity required by the needle for various thick-
nesses is equal to the difference of thickness, but the action of the needle
unless it were corrected by the action of the hook and check, as will be
presently explained, would be to make the difference equal to twice that
amount. This action is caused by the unfinished stitch and the location of the
slack thread on the opposite side of the work to that from which the needle
thread is supplied, as will now be explained by the aid of Fig. 14. When the
eye of the needle reaches the cloth at 30, the loop 22 below the table will be
shortened by the thickness of the cloth, as shown at 21, and when it has
descended through the cloth the loop will be shortened again by the thickness
of the cloth, as shown at 20. If the length of the loop below the table was
the same in sewing thick as in sewing thin goods, the quantity of thread
drawn from the spool would be such that the under or locking thread would
be just drawn to the under side. The needle cannot commence drawing
thread from the spool until it has drawn the loop below the cloth tight around
the check, spool case, and hook, on account of the friction produced on the
thread by the friction clamp J being greater than the friction on the thread
passing through the cloth at 21, hence by causing the length of loop to be
decreased as the cloth increases in thickness, the amount of the decrease will
be free to be drawn up by the needle, which will correspondingly delay the
commencement of drawing from the spool, and decrease the quantity taken.
This is effected partly by the position of the shoulder of the hook and the
check at the time of commencing to draw thread from the spool, and partly
by the shape of the heel or tail of the hook over which the thread rests during

page_text: the drawing of the thread. This is illustrated by Figs. 1 and 11, both of
which show the position of the parts at the time of commencing to take the
thread from the spool. Fig. 1 shows the positions with thick goods, and 11
with thin goods. It will be seen in Fig. 11 the rotating hook has passed
much further and the loop is much longer, its thread being in a tortuous
position, the part passing over the heel resting on the fullest part l. In Fig. 1
the hook is much less advanced, and the thread on the heel is on the lowest
part; which produces the necessary shortening of the loop for the aforesaid
correction. The length of the loop may be decreased to the desired extent by
cutting out the heel at l.
The improvement in the feeding device is best illustrated in Fig. 12, in
which, and in Figs. 2 and 3, T represents the feed bar applied under the work
plate in the manner common to what is known as the "four motion" feed,
and having the toothed dog U connected with it by a spring V to permit the
upward and downward movement to bite and release the cloth, but the dog
instead of being rigidly attached to the spring, as is usually the case, is
arranged to rock in such manner as to adapt itself to any increase or dimi-
nution of thickness' of the work, either sudden or gradual. The said dog is
made of a separate piece of steel' with a curved or rounded bottom, and a
conical cavity in the said bottom for the reception of the pointed end of an
adjusting screw w, screwed through a-block of metal V, which is rivetted or
otherwise secured to the spring V. Portions 18, 18, of the spring are extended
beyond it's connection with the said block to press upon the flat upper surfaces
of shoulders y, y, provided on the sides of the dog near the middle of it's
length, and so keep the dog on the point of the screw, on which it is free to
rock to accommodate itself to the varying thickness of the work. The vertical
movement of the feeding bar V to cause the dog U to engage with the cloth is
imparted by an incline on the periphery of the cam W, acting against the
bottom' of block V₁, and the longitudinal movement of the said bar is produced
by the broad inclined face of the said cam against the contact surface y of the
lever Y, shown partly in dotted lines in Fig. 3, which lever acts upon the feed
bar, and throws it forward in the direction that the teeth of the feed dog U are
inclined. The movement of the system in the opposite direction is produced
by the spring T¹. The face of the cam W which acts upon the lever Y is
made with its incline of sufficient elevation at the periphery to give the
feeding dog an extent of motion in the direction of the seam sufficient for the
longest stitch required to be made, and at the inner part next the shaft of an
elevation sufficient for the shortest stitch desired to be made, and the surface
in a radial direction inclined from one to the other. The lever Y is mounted
R

page_text: upon an axis Z, which is made to slide longitudinally in bearings in the
frame A transversely to the shaft C, so as to present the contact surface y to
that part of the cam W which will impart just the extent of motion to the
feed dog U that will give the desired length to the stitches. The advantage
in employing such a cam to actuate the feed bar is that the contact surface y
of the lever Y bears constantly upon it whatever may be the length of stitch
to be made, so that the movements of the feeding mechanism are noiseless
and without abruptness in any part, however fast the machine may be run.
The improvements in the thread spools are illustrated in Sheet 2 of the
Drawing, in which Fig. 15 is an end view, Fig. 16 a side view, and Fig. 17
an axial section of one of the improved spools, and Figs. 18, 19, 20, and 21
illustrate its construction; Figs. 22, 23, and 24 are axial sections of three
differently constructed spools; Fig. 25 is a side view corresponding with 24;
Fig. 26 illustrates the construction of the heads of the spools represented by
Figs. 22, 23, 24, and 25. Similar letters of reference indicate corresponding
parts wherever they occur in these Figures.
The spool shown in Figs. 15, 16, & 17 is composed of a thin tube A of
metal forming the body, and two discs B, B, of cardboard or thin metal
forming the heads. The tube A is formed of a piece of sheet metal, Fig. 18,
which has two ridges a, a, formed on one side by creasing or indenting the
opposite side, as shown at b, b, in Fig. 19, and is then rolled up to form the
tube shown in Figs. 20 and 21, and ridges a, a, then forming flanges all round
the tube. The two heads B, B, have holes made in their centres to fit the
ends of the tube, and after having been placed thereon up to the flanges a, a,
are secured by turning over the ends of the tube in an outward direction, as
shown at c, c, in Fig. 17.
The spool shown in Fig. 22 is formed by taking two discs C, C, of cardboard
or thin sheet metal, and making a series of cuts extending equal distances
across the centre, as shown at d, d, in Fig. 26, thus forming a series of
V-shaped parts e, e, which are then to be turned out at right angles to the
planes of the discs, and such parts e, e, of the one disc are inserted within the
corresponding parts of the other, as shown in Fig. 22, and secured by gumming,
pasting, glueing, or soldering to form the body of the spool.
The spool shown in Fig. 23 is composed of two dises C, C, like that repre-
sented in Fig. 26, and a tube D, the portions e, e, of the said disc being inserted
within the interior of the tube, and secured by glueing, gumming, pasting, or
soldering.
The spool shown in Figs. 24 and 25 is made of two discs C, C, having a
tube E inserted within the portions e, e. If the tube E be of cardboard, it

page_text: may be secured by glueing, gumming, or pasting, but if of metal it may be
secured by turning over its edge in an outward direction upon the outer faces of
the discs, as shown at f, f, in Fig. 24.
When the spools are to be filled they are placed in or upon a holder which
grasps and gives firm support to the heads, keeping them in place until the
filling has been completed and the spool is taken out. When the supports are
moved the heads present but little resistance, and yield to the pressure of
the thread which has been stretched in winding, and the thread, is thus
permitted to contract to its original length, thus preserving unimpaired its
elasticity. This quality makes these spools much superior to the rigid spools
commonly used for thread, which preserve the tension unavoidably produced in
winding, and so destroy the elasticity which it is very desirable to preserve for
the sake of making an elastic and durable seam. These spools can be,
made cheaper than the wooden spools upon which sewing thread is ordinarily
sold, and hence they can be used with advantage by the thread manufacturer,
while their extreme lightness and small bulk renders them applicable, when.
made of proper shape, for carrying the under thread of sewing, machines
making a lock stitch, and so they enable the thread to be sold in condition
for use in such machines without rewinding, which consumes a considerable
portion of the operator's time. The spool S carrying the under thread in
the machine represented in Sheet 1 of the accompanying Drawing is of
this kind, as also the spool F carrying the upper t
thread.
Having described the nature of this Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,―
First, the delivery to the needle of a sewing machine at each stitch a
measured length of thread corresponding to the thickness of material to be
sewed, and the drawing up of such measured length of thread by a uniform
and positive action to complete the stitch by means of the needle and its
actuating mechanism, a gripper or clamping device for holding and clasping the
needle thread above the cloth, and an independent thread-drawing device, the
whole so combined as to co-operate substantially in the manner herein specified,
whether the said independent thread-drawing device consists or is in part
constituted by the loop check r, or consists of any other contrivance or contri-
vances by which the same result is effected.
Secondly, the employment, in combination with the devices which control
the needle thread in delivering the same to the needle and tightening the
stitch, of a device for drawing sufficient thread from the bobbin to make the

page_text: next stitch in advance of its delivery to the needle, substantially in the manner
and for the purpose described.
Thirdly, forming the clamping device or gripper for the needle thread by
the combination of a bent lever L with a plate K on the needle. arm or their
equivalents, operated by the stop i on the connecting rod M¹, substantially as 5
described.
Fourthly, the employment, in combination with the rotating hook, of a spool
case placed diagonally to the axis of motion of the hook, and held in position'
by any appropriate devices, to enable a large bobbin or spool to be used for
carrying the under thread-and the loop of the needle thread to be passed' I
around it more readily, substantially as herein set forth.
Fifthly, the employment, in combination with a needle and rotating hook for
manipulating the needle thread, of a loop check, constructed and operating
substantially as described.
Sixthly, the employment of a detached or movable feed" dog as described,
in combination with the feed mechanism, substantially as herein specified.
Seventhly, the employment, in combination with the feeding mechanism, of
a variable cam and adjustable contact surface for giving a graduated movement
of the feeding instrument, substantially as herein specified.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Twenty-second day of April, in the year of
our Lord One thousand eight hundred and sixty-three.
Witness,
. W. G. E. SWINNOCK,
53, Chancery Lane,
London.
W. CLARK.
(L.S.)