CERTAIN IMPROVE- MENTS IN LOCK-STITCH SEWING MACHINES
Year: 1881

page_text: LETTERS PATENT to Bristow Hunt, of Serle Street, Lincoln's Inn, in the
County of Middlesex, Gentleman, for an Invention of "CERTAIN IMPROVE-
MENTS IN LOCK-STITCH SEWING MACHINES." A communication from abroad
by Joseph Bond, junior, and Charles Mosely Swain, both of Philadelphia,
Pennsylvania, in the United States of America.
PROVISIONAL SPECIFICATION left by the said Bristow Hunt at the Office
of the Commissioners of Patents on the 17th March 1881.
BRISTOW HUNT, of Serle Street, Lincoln's Inn, in the County of Middlesex,
Gentleman. "CERTAIN IMPROVEMENTS IN LOCK STITCH SEWING MACHINES."
A communication from abroad by Joseph Bond, junior, and Charles Mosely Swain,
both of Philadelphia, Pennsylvania, in the United States of America.
This Invention relates to improvements in that class of lock-stitch sewing
machines in which a loop of needle thread is passed over a stationary spool case or
shuttle by a rotating hook, and the Invention relates to mechanism, fully described
herein after, by the aid of which a complete stitch is formed during every complete
stroke or up and down movement of the needle, instead of one stitch being com-
pleted during the formation of the next stitch, an objectionable feature in other
machines of the class to which the Invention relates, a further object of this part of
the Invention being to prevent the drawing of the slack needle thread through the
fabric while the eye of the needle is in the same.
The Invention further relates to the driving of the counter shaft from the main
shaft of the machine by simple appliances which will permit the making of machines
with high stationary arms without any material additional expense.
The Invention further relates to certain devices, described hereinafter, for
operating and imparting pressure to the presser bar, the object of the devices being
to avoid well known objections to ordinary presser bar attachments, and a further
object being to afford facilities for operating the presser bar at a point most
convenient for the manipulation of the same.
The Invention further relates to certain feeding mechanism, the main object of
which is to prevent the dragging of the cloth and the displacement of the layers of
cloth as it feeds forward in the machine.
The Invention further relates to a device, described hereinafter, for imparting
tension to the spool or shuttle thread as it leaves the spool case.

page_text: A further object of the Invention is to readily and securely clutch a pulley to
the driving shaft, to release the pulley therefrom with equal readiness, and to
provide for the turning of the shaft in either direction when the pulley is released
therefrom.
A preliminary understanding of the main features of the machine may be best
obtained by prefacing the description with an explanation of the mode of forming
the stitch.
The mechanism for this purpose comprises an upper rotating disc provided with
a hook, a reciprocating needle bar provided with the usual eye pointed needle, a
cloth plate, a spool case, and a lower rotating disc provided with a hook. The
spool case is stationary, and held in a position eccentric as regards the lower disc
and the circular course of its hook, for a purpose rendered apparent hereinafter.
.
The needle thread passes through a retaining and releasing device, consisting of
two pressure discs, one pressed against the other, and being close together in the
middle, but diverging towards the peripheries, so that the thread when taking a
course between these discs near the middle of the same will be arrested, but will be
free when it takes a course near the peripheries thereof.
After passing this retaining and releasing device the needle thread passes through
an eye on the top of a vertically adjustable plate, thence through central and lower
eyes in the same plate, and thence through the eye of the needle.
Let it be supposed that the hook of the upper disc has in its revolution just
released a loop of needle thread between the retaining and releasing device and the
said top eye, and that the needle is descending and commencing to pass through
the fabric on the work plate, the lower disc meanwhile revolving in the same
direction as the upper one. When the needle has descended to the limit of its
downward movement, and has commenced to ascend, it thereby forms an incipient
loop of needle thread, the said loop being in a proper position to be seized by the
hook of the lower disc. (It should be understood that the needle in descending
took up a portion of the slack of the thread.) This hook then seizes the loop of
the needle thread, and as the needle rises this loop is necessarily enlarged; but this
enlargement of the loop is not due to the taking up of any more of the slack thread
between the said retaining and releasing device and the said upper eye, but to the
rising of the needle, for it is important that there should be no pulling of the
thread through the eye of the needle while the said eye is in the fabric. The
needle continues to rise until it has nearly reached the limit of its upward move-
ment, and the loop of needle thread has been extended and carried nearly over the
spool case, the additional thread required for the enlargement of the loop being
derived from the slack between the said device and the upper eye, which slack is
thus entirely taken up. A still further distension of the loop is required before it
can be carried entirely over the spool case, and this additional thread is derived
from an upper spool carried by the arm of the machine. When the loop has been
drawn over the nose of the spool case and released from the hook of the lower disc
the needle is commencing its downward movement, and the hook of the upper disc
is again about to seize the thread between the retaining and releasing device and
the said top eye; and as soon as the said hook has seized the thread between the
said device and eye the course of the thread is so changed as to be caught between
the pressure discs of the said device, so that no thread can be derived from the
upper spool, the thread demanded by the continued movement of the book of the
upper disc being derived from the slack below the fabric, and the hook not only
takes up this slack, but tightens the stitch formed by the interlocking of the needle
thread with the thread from the spool case. A further and very slight movement
of the upper disc is followed by the releasing of the loop, after which there will be
a repetition of the above described operations in forming another stitch.
In machines of the class to which this Invention relates, that is, in a machine
having a rotating hook for carrying a loop of needle thread over a stationary spool
or shuttle, the stitch has not heretofore been completed until the succeeding stitch
was partially made, and this involved the necessity in tightening the stitch of

page_text: pulling the thread not only through the fabric, but across so much of the same as
intervened between the incompleted stitch and the point where the needle is
passing through the fabric for the formation of an adjoining stitch, this being
of course objectionable, as the needle must be strained and the thread deteriorated
when it is dragged in contact with the fabric, both vertically and horizontally, and
often results in the breaking of the thread.
It will be seen by the foregoing description that a stitch is completed during
every complete stroke or up and down movement of the needle, and that the stitch
is completed before the eye of the needle is in the fabric.
The eccentricity of the spool case in respect to the circular path of the hook of
the lower disc contributes to bring this about, the position of the spool case being
such that the loop of needle thread can be passed over its nose at a much earlier
stage in the rotation of the hook than if the said spool case should be situated
concentrically with the path of the hook, and consequently more time is afforded
for the taking up of the slack thread than in other machines of this (class. The
position of the needle in respect to the spool case also contributes to the attainment
of the desired result, the needle being so situated as to permit the spool case to
occupy the position referred to, and to this position is due, as before remarked, the
prompt passage of the loop over the spool case.
The line in which the needle reciprocates is considerably to the right of a vertical
line drawn through the centre of the lower disc, and to this is due the fact that the
hook on the edge thereof seizes the incipient loop of needle thread at the right
point, that is as near to the eye of the needle as possible.
It will be understood that different appliances may be used for taking up the
slack between the retaining and releasing device and the upper eye; a vibrating
arm with a hook may, for instance, take the place of the rotating disc and its hook,
but the latter are to be preferred, as a rotary motion can be more directly and
economically obtained than a vibrating motion.
With reference to the general construction of the machine, the stationary arm
projects from a hollow standard which is permanently secured to the base plate.
The driving shaft has two bearings in the stationary arm and a supplementary
bearing in a plate secured to the rear of the hollow standard, this shaft being
provided with fly wheel, grooved pulley, and a clutch, which will be fully described
hereinafter.
A countershaft has suitable bearings on the underside of the bed plate, and is
provided with a crank wheel, the pin of which is connected to a duplex crank on
the driving shaft by a rod arranged to slide in a guide from which project at
right angles to the guide pins one on each side of the said guide and at right
angles to the rod, the pins being adapted to other guides secured to the hollow
standard.
The parallelism of the rod is ensured at all times, and the turning of the counter
shaft must be as certainly simultaneous as though the two shafts were geared
together by ordinary cog wheels.
This movement is applicable to many machines, but it is of especial importance
when viewed in connection with the bed-plate, counter shaft, and stationary arm
of a sewing machine, for in many sewing machines for special work it is desirable
for the stationary arm to be elevated much higher above the base plate than
in other machines, and all that is necessary to accommodate the above described
movement to machines in which the height of the stationary arm from the bed
plate varies is to make the rod longer or shorter as the distance between the two
shafts may require.
The driving pulley and clutch may be applied to the counter shaft instead of to
the upper shaft, in which case the duplex crank must be on the said lower shaft,
and the single crank on the shaft above.
At the outer end of the stationary arm and forming part of the same is a plate
to which is secured a detachable plate of similar size and form, and between these
two plates are the guides for the needle bar and presser-bar.

page_text: In a cross-head on the needle-bar is a curved slot through which passes a crank-
pin projecting from a disc on the driving shaft, the head of the pin projecting
beyond the needle bar, and to this head is secured the upper disc previously referred
to in describing the formation of the stitch, the disc being secured at a point so
far from its centre that it shall rotate concentrically with the driving shaft. There
is an opening in the detachable plate behind the disc to permit the free movement
of the crank pin.
•
. The device for operating the presser bar is as follows:-On the upper end of the
bar and projecting therefrom is a plate through the forked end of which passes an
elastic or spring shaft on the end of which is an eccentric between the plate and a
projection thereon.
.
This elastic shaft has two bearings, one forming a part of a vertically adjustable
pin passing through a projection on the stationary arm of the machine, the
adjustability being effected in the present instance by threading the pin and
adapting it to a threaded orifice in the said projection. The other bearing of the
shaft is in the standard, and the shaft is here furnished with an arm which passes
through a slot in the standard, and is situated at a convenient point for being
manipulated when the presser foot has to be raised or lowered.
When the shaft has been so turned that the eccentric has depressed the
presser bar and brought its foot into contact with the cloth, the shaft serves as a
spring to press the foot down on the cloth and this pressure may be increased or
diminished as circumstances may suggest or require by adjusting the bearing in the
standard.
The advantage of this device for operating the presser bar and foot will be best
understood by referring to the ordinary spiral spring for depressing the presser
bar in ordinary sewing machines, the effort to raise the bar being resisted by a
constantly increasing rigidity of the spring as the latter is compressed, a defect
which this feature of the present Invention overcomes, for the higher the presser
foot is raised the less will be the resistance exerted by the spring shaft. Moreover
there is no necessity for turning the presser bar round, so as to be held up as in
ordinary sewing machines, the eccentric serving to retain the bar in an elevated
position. It is advisable moreover that the front of the machine should be free
from the usual appliances required for raising and releasing the presser foot, and
that the handle for manipulating the same should be within reach of the right
hand of the operator.
The peculiar character of the feeding device and its mode of operation is as
follows-The feed bar receives the usual horizontal reciprocating movement only,
and to it an arm is pivoted, so that while the arm reciprocates with the bar it can
have a vibrating movement in a vertical plane independently of the bar, the arm
having near its outer end a pointed projection or feed pin passing freely through a
horizontal portion of the bar, the upper surface of which portion is on a level
with or slightly above that of the cloth plate and immediately below the
presser foot. During the rearward movement of the bar the arm depressed so
that its pin is retracted beneath the surface of the horizontal portion of the bar;
but when the bar has reached the limit of its rearward movement the arm rises
and its pin passes through the fabric, the presser. foot having a longitudinal
groove to receive the point of the pin. During the forward movement of the
bar the fabric is carried forward by the pin and the desired feed accomplished.
. The advantage of this feed mechanism is due to the fact that the horizontal
portion of the bar moves with the fabric in feeding, so that there is no drag
on the fabric itself; even when there are several thicknesses of fabrics there can be
no drag of one on the other, owing to the feed pin which penetrates through all the
layers.
While different devices may be used for imparting the desired movements to the
feed bar and arm, the following is a description of the mechanism which has been
adopted for this purpose.
Ta the underside of the base plate is nivoted by means of an adiustable pin the

page_text: feed lever, which is actuated by two eccentrics or cams on the counter shaft in
the following manner:-The feed lever rests on an arm which is loosely connected,
to the underside of the base plate, the feed lever being also caused to bear in the
manner explained hereinafter against a shoulder on the said arm. One cam acting.
on one part of this arm tends to reciprocate it horizontally, the other cam acting
on the other part of the arm tending to vibrate the same in a vertical plane. Hence
the outer end of the feed lever must receive a combined vertical and lateral
vibrating movement.
.
The feed bar is arranged to slide in guides in the underside of the base plate, its
outer end being acted on by a spring, the tendency of which is to force the bar in a
certain direction. The end of the feed lever passes through a slot in the said pivoted
arm and through a slot in the feed bar.
There are two vertical pins or projections on the feed lever, and these fit snugly
between the top and bottom of the slot in the pivoted arm, so that the latter can
receive a vertical vibrating motion only from the said feed lever, the slot being too
long to permit the arm to be influenced by the horizontal vibration of the lever;
the feed bar however has a slot of such dimensions for admitting the end of the
feed lever that it can only receive a horizontal reciprocating movement therefrom,
or rather a movement in one direction from the lever and in the other direction
from the last referred to spring, and it is this spring which maintains the lever in
contact with the shoulder on the said arm.
The spool case consists of two parts which may be entirely separable from each
other or hinged together, the two parts being so dished as to present when united a
chamber large enough to receive the spool.
This spool has two journals in one part of the case, one being pointed and having
its bearing in a block which is so acted upon by a spring that the latter will keep
the spool in its place, but can be retracted so as to set this journal at liberty and
permit the withdrawal of the journal from its bearing. The spring also tends
to force the opposite end of the spool against a face formed in the same part of the
case.
The course of the spool or shuttle thread is as follows:-It is first passed from
the spool through an eye near one edge of the spool carrying part of the case, thence
through a channel forming a communication between the said eye and a similar eye
through which it then passes and whence it takes a course between the end of the
'spool and the above mentioned adjacent face of the spool case, thence through a slot
and out through an eye.
In many sewing machines there is a tendency of the thread to pass from the
spool and become caught within the case, and this involves the necessity of stopping
the machine for the readjustment of the straying thread. This difficulty is avoided
according to the present improvements by compelling the thread to take the course
which it might accidentally take with the above results, that is, over one end of the
spool; but there is prepared in the spool case a face, between which and the end of
the spool the thread receives the desired tension which is obtained while entanglement
of the thread is prevented.
The shuttle has a nose over which the loop of upper thread is carried by the
hook of the said lower disc, the nose having a groove through which the hook can
take its course in carrying the loop of needle thread over the case.
The shuttle is held in place by and between a socket on a bracket and a socket
on a bar which is so fitted to the bracket as to be adjustable thereon, a set screw
and thumb nut being provided for securing the bar after adjustment, the bracket
being secured to the underside of the base-plate.
With reference again to the needle thread guide it may be remarked that its
vertical adjustability is of importance, for it may be necessary for the rotating hook
to take up more or less of the needle thread, as the thickness of the fabric may
suggest, and it will be seen that the nearer the top eye of the thread guide
is to the said retaining and releasing device the greater will be the length of thread
taken up.

page_text: The construction of the clutching device is as follows:-To the outer end of the
driving shaft is secured a wheel or disc, which has at the edge an internal flange,
the outer face of the disc having a rounded annular rib forming a hand wheel by
means of which the disc with the shaft may be turned in either direction.
Surrounding this wheel or disc is a flanged pulley loose on the driving shaft, the
flange of this pulley overlapping the flange of the disc, and the hub of the pulley
having an external groove for the reception of the driving band and an internal
annular recess for the reception of a sleeve between an internal shoulder at the
outer end of which and a collar on the driving shaft intervenes a coiled spring, the
tendency of which is to move the sleeve outward.
The inner end of the sleeve is tapered or conical and in the outer end of the
sleeve are formed two recesses, which are adapted to a V-shaped plate bolted to
and projecting from the said supplementary bearing of the driving shaft, the one
recess being shallow and segmental, so as to receive the rounded nose only of the
plate, the other recess being V-shaped and of such a depth as to receive almost the
entire projecting portion of the plate.
The sleeve is free to turn on the driving shaft, and has a projecting arm by
means of which a movement of rotation or partial rotation may be readily imparted
to it.
Hung to the inner face of the said flanged pulley is a lever, a short arm of
which has a rounded eccentric face, the long arm of the lever having a bent end
which projects through an opening in the hub of the pulley into the annular recess
of the said hub, a spring acting on the lever and tending to draw the bent end of
the same into the said recess.
The operation of the device is as follows:-When the parts are in one position
the pulley is clutched to the fixed disc on the shaft by means of the lever, the
eccentric face of the short arm of the latter being in contact with the internal
flange of the disc, and the bent end of the long arm of the lever occupying a
position in the annular recess of the said hub, the sleeve being retracted and the
said V-shaped plate occupying a position in the deep slot of the sleeve.
As the pulley rotates the friction between the flange of the dise and the
eccentric face of the short arm of the lever tends to aid the said spring in moving
the lever in such a direction as to tighten the grip on the flange, so that the secure
clutching of the disc to the pulley is ensured.
When it is desired to release the disc and driving shaft from the pulley the
sleeve is turned by means of its projecting arm to another position, the V-shaped
plate acting as a cam and causing a simultaneous longitudinal movement of the
sleeve, so that the conical inner end of the latter acts upon the bent end of the
long arm of the lever and thrusts the same outward, thereby withdrawing
the eccentric face of the short arm of the lever from contact with the flange of 4
the disc, and thus releasing the pulley from the same and from the shaft.
The sleeve is then retained in position by the engagement of the end of the
V-shaped plate with the said shallow recess, and when it is desired to again clutch
the pulley to the shaft the sleeve is turned forward until the said plate occupies
the other recess.
When the pulley is released from the shaft the latter can be readily turned
in either direction by manipulating the hand wheel forming part of the disc, this
feature being of considerable importance, as it is desirable in many cases to effect
certain adjustments of the needle bar after the driving pulley has been released
from the shaft, which adjustments in the absence of the hand wheel cannot
conveniently be made.
The hand wheel may if desired be made separate from and secured to the shaft
independently of the disc, although the construction described is preferred on
account of its compactness and convenience.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed'
by the said Bristow Hunt in the Great Seal Patent Office on the 17th
September 1881.
r
BRISTOW HUNT, of Serle Street, Lincoln's Inn, in the County of Middlesex,
Gentleman. "'CERTAIN IMPROVEMENTS IN LOCK-STITCH SEWING MACHINES.".
(A communication from abroad by Joseph Bond, junior, and Charles Moseley.
Swain, both of Philadelphia, Pennsylvania, in the United States of America.)
This Invention relates to improvements in that class of lock stitch sewing
machines in which a loop of needle thread is passed over a stationary spool case
or shuttle by a rotating hook; and the Invention relates to mechanism, fully
described hereinafter, by the aid of which a complete stitch is formed during
every complete stroke or up and down movement of the needle and during every
rotation of the hook.
The Invention further relates to the driving of the countershaft from the main
shaft of the machine by simple appliances, which will permit the making of
machines with high stationary arms without any material additional expense.
The Invention further relates to certain devices, described hereinafter, for
operating and imparting pressure to the presser bar, the object of the devices being
to avoid well known objections to ordinary presser bar attachments, and a further
object being to afford facilities for operating the presser bar at a point most
convenient for the manipulation of the same.
The Invention further relates to certain feeding mechanism, the main object of
which is to prevent the dragging of the cloth and the displacement of the layers
of cloth as it feeds forward in the machine.
The Invention further relates to a device, described hereinafter, for imparting
tension to the spool or shuttle thread as it leaves the spool case.
A further object of the Invention is to readily and securely clutch a pulley to
the driving shaft, to release the pulley therefrom with equal readiness, and to
provide for the turning of the shaft in either direction when the pulley is released
therefrom.
The Invention is illustrated on the accompanying Sheet of Drawings, in which
Fig. 1 represents a side view of the improved sewing machine, the framework
being in section and the operating parts in elevation; Fig. 2 is a section on the
line 1-2; Fig. 3, an inverted plan view of the machine exhibiting the underside
of the base plate; Fig. 4, an end view of the machine looking in the direction of
the arrow 1, Fig. 1; Fig. 5, the same as Fig. 4 after the removal of the front plate
and other appliances, the base in this view being in section on the line 3-4,
Fig. 1; Fig. 6, a section on the line 5-6, Fig. 1; Fig. 7, a section on the line
7-8, Fig. 1; Fig. 8, a perspective view of the device for operating the presser
foot; Figs. 9 and 10, perspective views of detached portions of the feed motion;
Fig. 11, views drawn to an enlarged scale and showing the construction of the
spool case holder; Figs. 12, 13, 14, 15, 16, and 17, views also drawn to an enlarged
scale of the spool and spool case; Fig. 17*, a view of the take up hook; Figs. 18,
19, 20, 21, 22, and 23, diagrams showing the mode of forming the stitch by the
machine; and Figs. 24, 25, 26, 27, and 28, views illustrating the clutching device.
A preliminary understanding of the main features of the machine may be best
obtained by prefacing the description with an explanation of the mode of forming
the stitch, as illustrated by the diagrams, Figs. 18 to 23 inclusive.
In all these diagrams A represents a rotating disc provided with a hook a; B,
the reciprocating needle bar provided with the usual eye pointed needle; C, the
cloth plates; E, a stationary spool case; and F, a rotating disc provided with a
hook b.
The stationary spool case is held in a position eccentric as regards the disc F and
the circular course of its hook, for a purpose rendered apparent hereinafter.
The needle thread a passes through a retaining and releasing device c, consisting

page_text: of two discs, one pressed against the other, and shown in Fig. 1, the discs being
close together in the middle but diverging towards the peripheries, so that the
thread when taking a course between these discs near the middle of the same
will be arrested, but will be free when it takes a course near the peripheries of the
discs.
After passing this device c the needle thread passes through an eye d on the
top of a vertically adjustable plate G, thence through eyes d¹ and d³ in the same
plate, and thence through the eye of a needle.
In Fig. 18 the book a of the disc A, which is revolving in the direction of its
arrow has just released a loop of needle thread between the device c and eye d, and
the needle is descending and commencing to pass through the fabric on the work
plate, the disc F meanwhile revolving in the direction of the arrow.
In Fig. 19 the needle has descended to the limit of its downward movement and
has commenced to ascend, thereby forming an incipient loop of needle thread, the
said loop being in a proper position to be seized by the hook b of the disc F. It
should be understood that the needle in descending took up a portion of the slack
of the thread a
In Fig. 20 the hook b has seized the loop of the needle thread, and as the needle
rises this loop is necessarily enlarged, but this enlargement of the loop is not due
to the taking up of any more of the slack of the thread between the device c
and eye d, but to the rising of the needle, for it is important that there should be
no pulling of the thread through the eye of the needle while the said eye is in the
fabric.
In Fig. 21 the needle has nearly reached the limit of its upward movement and
the loop of needle thread has been extended and carried nearly over the spool
case, the additional thread required for the enlargement of the loop being derived
from the slack of the thread a between the device c and eye d, which slack is thus
entirely taken up.
A still further distension of the loop is required before it can be carried entirely
over the spool case, and this additional thread is derived from the upper spool,
shown in Fig. 1.
In Fig. 22 the loop has been drawn over the nose of the spool case and released
from the hook b, the needle is commencing its downward movement, and the
hook a of the disc A is about to seize the thread between the device cand eye d.
. As soon as the hook a seizes the thread between the device c and eye d the
course of the thread is so changed as to be caught between the discs of the said
device (see Fig. 23), so that no thread can be derived from the upper spool, the
thread demanded by the continued movement of the hook a being derived from
the slack below the fabric, and the hook not only takes up this slack but tightens
the stitch formed by the interlocking of the needle thread with the thread from
the spool case.
A further and very slight movement of the disc A beyond the position shown
in Fig. 23 will (owing to the inclined back of the hook shown in Fig. 17*) be.
followed by the releasing of the loop, as shown in Fig. 18, after which there
will be a repetition of the above described operations in forming another stitch.
In machines of the class to which this Invention relates, that is, in a machine
having a rotating hook for carrying a loop of needle thread over a stationary
spool or shuttle, complicated devices have been heretofore employed for rotating
the hook, whereas according to the present Invention such complicated devices_are
dispensed with and the hook is caused to make but one rotation for each complete
stroke or up and down movement of the needle, so that it can be driven directly
from and at the same speed as the main shaft, a complete stitch being made and
drawn up on each rotation of the hook.
The eccentricity of the spool case in respect to the circular path of the hook b
contributes to bring this about, the position of the spool case being such that the
loop of needle thread can be passed over its nose at a much earlier stage in the
rotation of the hook than if the said spool case should be situated concentrically

page_text: with the path of the hook, and consequently more time is afforded for the taking
up of the slack thread than in other machines of this class. The position of the
needle in respect to the spool case also contributes to the attainment of the desired
result, the needle being so situated as to permit the spool case to occupy the
position shown, and to this position is due, as before remarked, the prompt passage
of the loop over the spool case.
It will be seen, on reference to Fig. 18, that the line in which the needle
reciprocates is considerably to the right of a vertical line drawn through the centre
of the disc F, and to this is due the fact that the hook b on the edge of the disc
seizes the incipient loop of needle thread at the right point, that is, as near to the
eye of the needle as possible.
It will be understood that different appliances may be used for taking up the
slack between the device c and eye d; a vibrating arm with a hook may, for
instance, take the place of the rotating disc and its hook, but the latter are to be
preferred, as a rotary motion can be more directly and economically obtained than
a vibrating motion.
Referring to the general construction of the machine, as illustrated in Figs. 3, 4,
5, 6, and 7, I is the stationary arm projecting from a hollow standard I', which is
permanently secured to the base plate H.
J is the driving shaft, having two bearings in the stationary arm and a
supplementary bearing in a plate secured to the rear of the hollow standard, this
shaft being provided with a fly wheel, grooved pulley, and a clutch, which will be
fully described hereinafter.
K is the counter shaft, having suitable bearings on the underside of the bed
plate, this shaft being provided with a crank wheel e, the pin of which is connected
to a duplex crank e on the driving shaft by a rod D arranged to slide in a guide L
from which project at right angles to the guide pins f, f, one on each side of the
said guide and at right angles to the rod, the pins being adapted to guides g, g,
secured to the hollow standard I¹.
The parallelism of the rod D is ensured at all times, and the turning of the
counter shaft must be as certainly simultaneous as though the two shafts were
geared together by ordinary cog wheels.
This movement is applicable to many machines, but it is of special importance
when viewed in connection with the bed plate, countershaft, and stationary arm
of a sewing machine, for in many sewing machines for special work it is desirable
for the stationary arm to be elevated much higher above the base plate than in
other machines, and all that is necessary to accommodate the above described
movement to machines in which the height of the stationary arm from the bed
plate varies is to make the rod D longer or shorter as the distance between the two
shafts may require.
The driving pulley and clutch may be applied to the shaft K instead of to the
upper shaft, in which case the duplex crank e must be on the said lower shaft and
the single crank on the shaft above.
At the outer end of the stationary arm, and forming part of the same, is a
plate N, to which is secured a detachable plate N', of similar size and form, and
between these two plates are the guides for the needle bar B and presser bar P.
In a cross-head on the needle-bar is a curved slot i, through which passes &
crank-pinj projecting from a disc Q on the driving shaft, the head of the pin
projecting beyond the needle bar, and to this head is secured the disc A, hereinbefore
referred to in describing the formation of the stitch, the disc being secured at a
point so far from its centre that it shall rotate concentrically with the shaft J.
There is an opening in the plate N¹ behind the disc to permit the free movement
of the crank pin.
The device for operating the presser-bar P is shewn in perspective view in
Fig. 8. On the upper end of the bar and projecting therefrom is a plate R,
through the forked end of which passes an elastic or spring shaft S, on the end of
which is an eccentric k between the plate and a projection thereon.

page_text: '
This elastic shaft has two bearings, one forming a part of the vertically
adjustable pin passing through a projection on the stationary arm of the machine,
as best observed in Fig. 2, the adjustability being effected in the present instance
by threading the pin and adapting it to a threaded orifice in the said projection.
The other bearing of the shaft is in the standard I', and the shaft is here furnished!
with an arm m which passes through a slot in the standard, and is situated at a
convenient point for being manipulated when the presser foot has to be raised or
lowered.
When the shaft has been so turned that the eccentric has depressed the presser
bar and brought its foot into contact with the cloth, the shaft serves as a spring to
press the foot down on the cloth, and this pressure may be increased or diminished
as circumstances may suggest or require by adjusting the bearing l¹.
The advantage of this device for operating the presser-bar and foot will be best
understood by referring to the ordinary spiral spring for depressing the presser-bar
in ordinary sewing machines, the effort to raise the bar being resisted by a
constantly increasing rigidity of the spring as the latter is compressed, a'defect
which this feature of the present Invention overcomes, for the higher the presser.
foot is raised, the less will be the resistance exerted by the spring shaft. Moreover
there is no necessity for turning the presser bar round so as to be held up, as in
ordinary sewing machines, the eccentric serving to retain the bar in an elevated
position. It is advisable, moreover, that the front of the machine should be free
from the usual appliances required for raising and releasing the presser foot, and
that the handle for manipulating the same should be within reach of the right
hand of the operator.
The peculiar character of the feeding device and its mode of operation may be
best explained by reference to the perspective views, Figs. 9 and 10; V is the feed
bar to which a horizontal reciprocating movement only is imparted, and to this
bar the arms is pivoted at t, so that while the arm, reciprocates with the bar it
can have a vibrating movement in a vertical plane independently of the bar V, the
arm having near its outer end a pointed projection or feed pin y passing freely
through the horizontal portion 2 of the bar, the upper surface of which portion is
on a level with or slightly above that of the cloth plate, and immediately below
the presser foot.
"
During the rearward movement of the bar, the arm a is depressed, so that its pin y
is retracted beneath the surface of the horizontal portion 2 of the bar V, but when
the bar has reached the limit of its rearward movement, the arm s rises and its
pin passes through the fabric, the presser foot having a longitudinal groove to
receive the point of the pin. During the forward movement of the bar the fabric
is carried forward by the pin and the desired feed accomplished.
The advantage of this feed mechanism is due to the fact that the horizontal
portion of the bar V moves with the fabric in feeding, so that there is no drag on
the fabric itself; even when there are several thicknesses of fabric there can be
no drag of one on the other, owing to the feed pin which penetrates through all
the layers.
While different devices may be used for imparting the desired movements to the
feed bar and arm, the following is a description of the mechanism which has been
adopted according to the present improvements for this purpose.
To the underside of the base plate is pivoted by means of an adjustable pin n the
feed lever T which is actuated by two eccentrics or cams p, p³, on the counter
shaft in the following manner :-
The feed lever T rests on an arm V, Fig. 6, which is loosely connected to the
underside of the base plate, the feed lever being also caused to bear, in the manner
explained hereinafter, against a shoulder on the said arm V ; one cam acting on one
part of this arm tends to reciprocate it horizontally, the other cam acting on the
other part of the arm tends to vibrate the same in a vertical plane. Hence the
outer end of the feed lever must receive a combined vertical and lateral vibrating
movement.

page_text: The feed bar V is arranged to slide in guides on the underside of the base plate,
its outer end being acted on by a spring u, Fig. 3, the tendency of which is to force
the bar in the direction of the arrow, Fig. 5. The end of the feed lever T passes
through a slot win the pivoted arms and through a slot in the bar V:
There are two vertical pins or projections v, v, on the feed lever, and these fit
snugly between the top and bottom of the slot w in the arm 8, so that the latter can
receive a vertical vibrating motion only from the said feed lever, the slot w being
too long to permit the arms to be influenced by the horizontal vibration of the lever,
the feed bar, however, has a slot of such dimensions for admitting the end of the
feed lever, that it can only receive a horizontal reciprocating movement therefrom, or
rather a movement in one direction from the lever, and in the other direction from
the spring u, and it is this spring which maintains the lever in contact with the
shoulder (Fig. 6) on the arm V.
The spool case, which is shewn in Figs. 12 to 17, consists of two parts W, W¹,
which may be entirely separable from each other, as shewn, or hinged together, the
two parts being so dished as to present when united a chamber large enough to
receive the spool X.
This spool has two journals on the part W₁ of the case, the pointed journal 4
having its bearing in a block 5 (Fig. 17), which is so acted upon by a spring that
the latter will keep the spool in its place, but can be retracted so as to set the
journal 4 at liberty, and permit the withdrawal of the other journal from its
bearing. The spring also tends to force the end 7 of the spool X against a face 8
formed in the part W₁ of the case.
The course of the spool or shuttle thread z will be best observed in Figs. 14, 15,
and 16. It is first passed from the spool through an eye 9, near one edge of the
part W¹ of the case; thence through a channel (Fig. 15), forming a communication
between the said eye 9 and a similar eye 10, through which the thread also passes,
and whence it takes a course between the end 7 of the spool and the above
mentioned face 8 of the spool case, thence through a slot 11 (Fig. 13), and out
:through an eye 12.
In many sewing machines there is a tendency of the thread to pass from the
spool, and become caught within the case, and this involves the necessity of
stopping the machine for the re-adjustment of the straying thread. This difficulty
is avoided according to the present improvements by compelling the thread to take
the course which. it might accidentally take with the above results, that is, over
one end of the spool, but there is prepared in the spool case a face, between which
and the end of the spool the thread receives the desired tension, which is obtained,
while entanglement of the thread is prevented:
The form of the shuttle is clearly defined in the Drawings; it has a nose 3, over
which the loop of upper thread is carried by the hook 6 of the disc F, as explained
in referring to the diagrams, Figs. 18 to 23, the nose 3 having a groove throngh
which the hook b can take its course in carrying the loop of needle thread over the
case.
The shuttle is held in place by and between a socket 14 on the bracket Y
(Fig. 11), and a socket 15 on a bar Y¹, which is so fitted to the bracket as to be
adjustable thereon, a set screw and thumb nut being provided for securing the bar
after adjustment, and the bracket is secured to the underside of the base plate, as
shown in Fig. 1.
Referring again to the needle thread guide G, it may be remarked that its vertical
adjustability is of importance, for it may be necessary for the rotating hook to take
up more or less of the needle thread as the thickness of the fabric may suggest, and
it will be seen that the nearer the eye d of the thread guide is to the device c the
greater will be the length of thread taken up.
The construction of the clutching device, of which an exterior view is shewn in
Fig. 1, is more minutely illustrated in Figs. 24, 25, 26, 27, and 28, and is as
follows:-
To the outer end of the driving shaft J is secured a wheel or disc D¹, which has

page_text: at the edge an internal flange a³, the 'outer face of the disc having a rounded annular
rib b¹ forming a hand wheel, by means, of which the disc with the shaft may be
turned in either direction.
E is a pulley loose on the shaft J, the flange d of this pulley overlapping the
flange a¹ of the disc D', and the hub e¹ of the pulley having an external groove f¹
for the reception of the driving band, and an internal annular recess g' for the
reception of a sleeve F¹ between an internal shoulder, at the outer end of which
and a collar on the shaft J intervenes a coiled spring h', the tendency of which is
to move the sleeve outward.
The inner end of the sleeve is tapered or conical, and in the outer end of the
sleeve are formed two recesses m³ and m³, which are adapted to a V-shaped plate n¹
bolted to and projecting from the bearing B¹, the recess. m² being shallow, and
segmental so as to receive the rounded nose only as the plate n¹, but the recess m³
is V-shaped and of such a depth as to receive almost the entire projecting portion
of the plate.
The sleeve F¹ is free to turn on the shaft J, and has a projecting arm J', by
means of which a movement of rotation or partial rotation may be readily imparted
to it.
Hung to the inner face of the pulley E¹ is a lever M, the short arm 8' of which
has a rounded eccentric face, the long arm 8 of the lever having a bent end which
projects, through an opening w¹ in the hub of the pulley, into the annular recess g¹
of the hub, a spring a acting on the lever M³, and tending to draw the bent end of
the same into the said recess.
The operation of the device is as follows:-When the parts are in the position
shown in Figs. 24 and 26 the pulley E' is clutched to the fixed disc D' on the shaft
by means of the lever M¹, the eccentric face of the arm s¹ of the latter being in
contact with the internal flange a¹ of the disc, and the bent end of the arm 8' of
the lever occupying a position in the recess g¹ of the hub e¹, the sleeve F' being
retracted, and the plate n' occupying a position in the deep slot m³ of the said
sleeve.
As the pulley E¹ rotates in the direction of the arrow, Fig. 26, the friction
between the flange a¹ and the eccentric face of the short arm of the lever M¹ tends
to aid the spring a³ in moving the lever in the direction of the arrow, Fig. 26, and
thereby tightening the grip on the flange, so that the secure clutching of the disc D'
to the pulley E¹ is ensured.
When it is desired to release the disc D' and shaft J from the pulley E¹ the
sleeve F¹ is turned, by means of its arm J' to the position shown in Fig. 25, the
V-shaped plate n'acting as a cam, and causing a simultaneous longitudinal move-
ment of the sleeve, so that the conical inner end of the latter acts upon the bent
end of the arm 8 of the lever, and thrusts the same outward in the direction of the
arrow, Fig. 27, thereby withdrawing the eccentric face of the short arm s' of the
lever from contact with the flange a¹ of the disc'D', and thus releasing the pulley E'
from the same and from the shaft.
The sleeve F is retained in the position shown in Figs. 25 and 27 by the engage-
ment of the end of the plate n¹ with the recess m³, and when it is desired to again
clutch the pulley E' to the shaft J the sleeve F¹ is turned forward until the plate n¹
occupies the recess m³, and the parts are restored to the positions shown in Figs. 24
and 26.
When the pulley E' is released from the shaft J the latter can be readily turned
in either direction by manipulating the hand wheel b¹ forming part of the disc D¹,
this feature being of considerable importance, as it is desirable in many cases to
effect certain adjustments of the needle bar after the driving pulley has been
released from the shaft, which adjustments, in the absence of the hand wheel b¹
cannot conveniently be made.
The hand wheel may, if desired, be made separate from and secured to the shaft
independently of the disc D¹, although the construction shown and described is
preferred on account of its compactness and convenience.

page_text: Having now described the nature and objects of the said Invention, together with
the manner in which the same is to be or may be performed or carried into practical
effect, I would remark in conclusion that what I claim as the improvements
communicated to me by the above named Joseph Bond and Charles Moseley
Swain, and constituting the Invention secured by the hereinbefore in part recited
Letters Patent are,―
1st. A sewing-machine in which the following elements are combined, namely,
first, a fixed shuttle or spool case; second, a uniformly rotating hook for carrying
the needle-thread round the spool case; third, a reciprocating needle; fourth,
mechanism whereby the hook is turned to the extent of one revolution while the
needle makes one complete up and down movement; and, fifth, a device for taking
up the needle thread, tightening the stitch, and releasing the said thread during.
one revolution of the hook, all substantially as herein before set forth.
2nd. The combination of the fixed spool case and rotating hook of a sewing
machine, with thread guides, and a rotating hook a for taking up and releasing
the needle thread, the said hook, having an inclined back as described, whereby the
automatic casting off of the loop is effected as the hook rotates, all substantially
as hereinbefore set forth and as illustrated on the accompanying Sheet of
Drawings.
3rd. The combination in a sewing machine of a reciprocating needle, a hook
rotating in a circular path, and a spool case held in a position eccentric in respect
to the circular path of the hook, and' arranged in respect to the needle, all sub-
stantially as hereinbefore set forth and as illustrated on the accompanying
Drawings.
4th. The combination of the rotating hook a, the thread guide d, and a
device c, for automatically releasing and retaining the thread controlled by the
book, substantially as hereinbefore specified and as illustrated on the accompanying
Drawings.
5th. The combination of the fixed shuttle or spool case, the, rotating hook b,
and rotating thread-controlling hook a, with the adjustable thread guiding plate G,
substantially as hereinbefore described and as illustrated on the accompanying
Drawings.
6th. The combination of the slotted needle-bar B, the driving shaft having a
disc Q, and the crank pinj projecting through the slot of the needle-bar and beyond
the same, for receiving the disc A, all being constructed substantially as herein-
before specified and as illustrated on the accompanying Drawings.
7th. The combination of the head N of the stationary arm of the machine and
detachable plate N' with the slotted needle-bar, the rotating hook a attached to
a disc or arm situated outside the detachable plate and secured to the pin,
through the medium of which the driving shaft operates the needle-bar, all being
constructed substantially as hereinbefore set forth and as illustrated on the
accompanying Drawings.
8th. The combination of the shafts J and K with a rod D connecting cranks
on the two shafts together, and with a laterally sliding guide L adapted to the
said rod, all substantially as hereinbefore set forth and as illustrated on the
accompanying Drawings.
9th. The combination of the presser-bar of a sewing-machine with an elastic rod
or shaft provided with an eccentric or cam adapted to the upper end of the said
presser bar, and serving as a medium through which the bar may be operated, and
of imparting pressure to the bar, all substantially as hereinbefore described and as
illustrated on the accompanying Drawings.
10th. The combination in a sewing-machine of the presser-bar with an elastic
rod or shaft having a cam or eccentric adapted to the said bar, and two bearings
for the said shaft or rod, one bearing being adjustable for causing the shaft to exert
more or less pressure on the presser bar, all substantially as hereinbefore set forth
and as illustrated on the accompanying Drawings.
11th. A sewing-machine feeding device consisting of a bar V having a portion 2

page_text: on a level with or slightly above the cloth plate, and a pivoted arm a carrying
the feed point or points with mechanism, whereby both bar and arm are inter-
mittently reciprocated horizontally, and whereby the arm is made to intermittently
vibrate vertically, all substantially as hereinbefore set forth and as illustrated on
the accompanying Drawings.
12th. The combination of the bar V, the arm s pivoted to the same, the vibrating
feed lever T adapted to slots in the said bar and arm, and having an adjustable
pivot, all substantially as hereinbefore set forth and as illustrated on the
accompanying Drawings.
13th. The combination in a sewing machine of the counter-shaft K and its two
cams p,p', the feed lever T and its adjustable fulcrum, the arm V loosely connected
'to the bed plate, and serving as a medium through which the movements of the
feed arm are determined, substantially as hereinbefore described and as illustrated
on the accompanying Drawings.
14th. The combination of the rotating hook 6 with a fixed shuttle having a
nose grooved for the reception of the hook.
15th. The combination of a spool case, a spool, and a spring acting on one
end of the spool, and tending to force the opposite end of the same against a face
formed in the case, with thread guides which direct the spool thread between the
end of the spool and the said face, all substantially as hereinbefore set forth and as
illustrated on the accompanying Drawings.
16th. The combination of the shaft J, the clutch disc D' secured thereto, the
loose pulley E¹ having a belt wheel f¹ and peripheral driving flange d¹, means for
clutching the pulley to the disc, and a hand wheel whereby the shaft J may be
turned when the disc D¹ is released from the pulley, all substantially as herein-
before set forth and as illustrated on the accompanying Drawings.
17th. The combination of the shaft J, the driving pulley E loose thereon, the
disc D¹ secured to the shaft, and having a flange a', the lever M¹ hung to the
pulley E¹, and having a short arm 8' with eccentric face, and means for operating
the said lever, all substantially as hereinbefore set forth and as illustrated on the
accompanying Drawings.
18th. The combination of the shaft J, the driving pulley E' loose thereon, and
having a hub e with annular recess g¹, the disc D¹ secured to the shaft, and having
a flange a', the lever M³ hung to the wheel E¹, and having a short arm s¹ with
eccentric face and long arm & with bent end, the spring ¹, the sleeve F' adapted
to the recess g', and having a conical end and means for reciprocating the said
sleeve, all substantially as hereinbefore specified and as illustrated on the
accompanying Drawings.
19th. The combination of the clutch actuating sleeve F¹ having an arm J and
a V-shaped recess m³, the frame B¹ having a V-shaped plate n' and a spring h¹
for maintaining the sleeve in contact with the said plate, all substantially as herein-
before described and as illustrated on the accompanying Drawings.
20th. The combination of the clutch actuating sleeve F1 having an arm J¹, a
shallow recess m³, and a deep recess m³, the V-shaped plate n¹ and the spring h',
all substantially as herein before described and as illustrated on the accompanying
Sheet of Drawings.
In witness whereof, I, the said Bristow Hunt, have hereunto set my hand
and seal, this Seventeenth day of September, in the year of our Lord One