IMPROVEMENTS IN SEWING MACHINES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Herbert John Allison at the Office of
the Commissioners of Patents on the 18th May 1883. Communicated to him
from abroad by Christian Wuterich, of the City, County, and State of New
York, United States of America,
"
HERBERT JOHN ALLISON, of the firm of Allison Brothers, Patent Agents, of 41
Southampton Buildings, Holborn, in the County of Middlesex IMPROVEMENTS
IN SEWING MACHINES" a communication to me from abroad by Christian
Wuterich, of the City, County, and State of New York, United States of America,
These improvements in sewing machines, relate to means for sewing or
fastening heavy leather work, such as shoe soles, belting, harness, trunk work, etc.
The object of this invention is to produce a machine for sewing both the insole
and outsole of a shoe; with the same machine, using either two or three waxed
threads, and forming the seam in each instance on the outside, thereby obviating
the difficulty of wearing shoes with waxed-thread seams inside of them, the
tendency of inside seams being to draw and cramp the foot, in consequence of
the perspiration or heat of the foot acting injuriously upon the waxed thread.
The machine is so simply constructed that it may become of universal application
in even small shops, and may be used not only for sewing on the soles of shoes,
but also for sewing all articles made of thick leather or other heavy material.
All of the operative parts of the machine will be built upon a suitable frame,
portions of which, or attachments thereto, will furnish the proper bearings for all
axles or other bearings, but the form of the said frame may be widely varied, and
in fact the general form of the machine, including the operative parts, may be
of such varied construction as to render a minute description of the same
impracticable, therefore specific description will be limited to such parts and their
functions as are of essential importance, and only a general description given of
those parts which constitute the mere mechanical devices or movements required
or used to produce the general results.
The specific and fundamental parts of the machine consist of jaws which hold the
work while it is being sewed, a rocking needle head with its curved needle, and
also a rocking guide head, with its loop catcher and curved stitch guide, a lifter
hook, and a shuttle, together with a tension arm; while the non-essential and
variable parts are 'the various mechanical devices which are employed to operate
I Price 6d1

page_text: these essential parts, and the subjoined description relating to these non-essential
parts, while necessarily specific as to the particular mechanism described, is only &
description of a specific way of operating the essential devices, which of themselves
must remain essential to the mechanism of the machine, though the operating
devices may be made in some other way than that described.
The jaws have two movements, viz.: first to close upon the work which is
placed between them, like a vise, and second a forward and backward movement
of about one-eighth of an inch, more or less, so as to carry the work forward
from stitch to stitch. These holding and feeding jaws will be best operated by
two operating arms or levers, the lower ends of which terminate in the said jaws
or holders, just above which the two arms or levers will be halved or jointed
together like a pair of tongs or shears, and in lieu of a pivot pin for uniting the
two said arms at the point of their intersection, they will be attached to a sliding
collar or sleeve, which will slide upon the hollow needle shaft. Either one or both
of the said jaw levers may open and close, shear like, but it is preferred that only
one of them shall move in this direction.
In one arrangement the said arms or levers have two small sheaves respectively
attached to them and resting against their respective supports or guides, both of
which in this instance are attached to and revolve with the driving shaft. One
rest or guide is a cam, the re-entering notch or formation, constructed either with
rectilinear or curved lines, is just sufficient to allow the jaws to open enough to
permit the work to stand free of the said jaws, (while the work is held on the
curved. needle hereinafter described,) and thereby permit the said jaws to move
back as will presently be described, so as to take a new hold on the material being
sewed, preparatory to moving it forward the proper distance to form the next
stitch. Except for the notch, the cam would be à circular disk, concentric with the
driving shaft to which it is fixed, and one roller or sheave on or attached to one
of the arms is held habitually against the periphery of this disk or cam by means
of a tension spring. The convex face of the cam between the re-entering points
constitutes about seven-eighths of the periphery of the cam, and during the rotation
of this portion of said cam, it, by pressing against the roller or sheave just
mentioned, will hold the jaw attached to the said arm tightly up to the other
jaw or upon the material placed between them; but when the said sheave or
roller drops into the notch or cam opening, the said jaw will open as above
`mentioned, so as to allow the two jaws to drop back and take a fresh hold upon
the work preparatory to the forward feed movement required.
In order to adjust the distance between the jaws, when they are closed, to fit
tightly upon different thicknesses of material, I make the attachment of the said
sheave or roller to the said lever or arm adjustable, by means of a thumb screw,
which moves a sliding block, on which is placed the bearing of the said sheave or
roller. A slot or seat in the arm or lever receives the sliding block, so that it
may easily slide therein, and the thumb screw is also seated in the said arm, which
forms its fulcrum.
By turning the thumb screw in, or out, as may be desired, the roller or sheave
may be adjusted accordingly, and in conformity therewith the distance between the
jaws when closed, regulated as desired.
The second rest for holding the second arm or lever in its proper place or position,
may be a stationary seat for pressing against the second sheave or roller, or it may
be, a disk fixed concentrically to the driving shaft and revolving therewith, as does
the cam above mentioned. This arrangement will reduce the frictional obstruction
necessary in the forward and backward sliding of the jaws required for the feed
movement. In order to adjust the machine by hand, so as to open or close the jaws
at pleasure, when putting work into or taking it from the machine, the cam is
attached to the driving shaft, so as to rotate with it by means of a ratchet wheel
fixed to the said shaft, but allowing the cam to turn freely on the said shaft,
except when engaged by a pawl, which is fulcrumed or pivoted to the side of the
cam. This arrangement permits the operator to turn the cam back, so that the

page_text: sheave will drop into the cam recess, thus allowing the jaws to be opened
temporarily by the operator whenever required.
The opening and closing of the jaws upon the work being operated as above fully
described, I will next describe the feeding movement, which consists of a short
reciprocating movement of the said jaws, to and from the front end of the machine.
The movement of the jaws must be made in one full reciprocating movement
forward and backward, at each rotation of the driving shaft, and the following
described mechanism is one way of producing this result.
A cam wheel is affixed to the said driving shaft, and in the face or periphery of
this wheel are cut two sets of cam faces. The use of the second of these will be
hereinafter explained, but the first, will consist of a continuous groove cut entirely
around the periphery of the said wheel, but in such a zig-zag form as to operate a
lever, as below described. This lever is fulcrumed to some suitable stationary part
of the machine, and the upper end of it terminates in a roller or sheave which fits
easily within the cam groove. The other end of the said lever is formed into a
bifurcated end which grasps and embraces a swivel clutch, so as to let the said
clutch band or swivel piece rotate or rock easily within it, but not to move laterally
out of it, as clutch pins secured in the two parts of the bifurcation will enter an
annular groove in the periphery of the clutch piece. The clutch piece is fixed to
the inner end of a sliding collar, which is placed concentrically around the needle
shaft, and carries on its front end the binged or jointed connection of the two jaw
arins. The curved groove in the face of the cam wheel, the lever, the clutch, the
sliding collar and the jaw arms are so constructed and combined, that at each
revolution of the driving shaft and its attached cam wheel the lever, actuated by
the cam wheel, will move the sliding collar and its attached arms forward and
backward, once, just the required distance to move the work from one stitch to the
next, and the time of the forward and retrogade movement of the said jaws for
this purpose, will be so combined with the mechanism for opening and closing the
said jaws upon the work, as above described; by reason of both operations being
worked by arbitrary movements from the same driving shaft, that the retrograde
movement of the said jaws will be performed during the time the said jaws are
opened, or freed from their hold upon the work, as described, and the forward
movement of the said jaws will be made during the time the said jaws are closed.
upon the work, thereby carrying the work along with them the distance required
from one stitch to the next.
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,
The formation of the cam wheel and its groove, is however such, that the rear-
ward movement of the jaws will be performed in the one-eighth of a revolution of
the driving shaft, or thereabouts, as above described for the opening of the said jaws
by reason of the construction of the operating cam as already mentioned, and
during the remaining seven-eighths of a revolution of the driving shaft, or nearly
in that time, the forward moveinent of the said jaws will first be accomplished, and
then the position of the jaws and their held work will remain stationary a sufficient
length of time for the needles to pass through the work, carrying with them the
threads and then drawing in the threads tightly by reason of the action of the
tension arm, so as to form one perfect and completed stitch at each revolution of
the machine.
11 7
The method of adjusting the length of the stitch will be by moving the fulcrum
or pivot of the actuating lever up or down, by means of one or more adjusting
screws, the aperture through the said levers being slotted, so as to permit the
fulcrum pin thereof the required vertical movement for this adjustment. When
this fulcrum pin or pivot is moved up, it is obvious the lower arm of the said lever
will be lengthened, and the lateral movement of the jaws will then be the greatest,
and when the said pivot pin is moved down, the lower arm of the lever will be
shortened, and the lateral movement of the jaws will then be the least, and in this
manner the operator can easily and quickly set the machine to sew a long or a
short stitch. :
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The sewing or stitching made by this machine is the joint work' of five distinct

page_text: .
devices, which perform, separate and specific operations in the formation of the
loop stitch which is the product of the machine. These separate devices are the
loop lifter, the curved needle, the stitch guide, and the tension arm, and these
several devices will now be described in the order named, and then will follow a
combined description of their united functions and operations.
The loop lifter is a small curved hook, and it is fixed to the overhanging end of
a shaft, at the front end of the machine. The shaft and its attached hooked lifter
have a rocking motion about the axis of the shaft, and a longitudinal sliding
'movement in the direction of the axis of the shaft. These movements of the lifter
are essential to the operation of the machine, but the mechanism for operating the
parts so as to produce these movements may of course be widely varied, but the
subjoined description of operating mechanism will illustrate the case.
The rock shaft has its. bearings in the frame, so as to allow the said shaft to
rotate or rock easily therein, but it is not confined in the said bearings by any
shoulder or collar, and it will consequently have freedom to move longitudinally
as. desired. At some convenient point on this shaft, there will be fixed to it a
cogged wheel, and at another convenient point in said shaft there will be a
circumferential groove. cut thereon, or in lieu thereof there will be a concentric
collar fixed to the shaft. In connection with the cogged wheel and the said groove
or collar, there will be respectively. placed two levers, and these levers will be
respectively fulcrumed by suitable pins to some part of the frame or its attach-
ments. These levers will be actuated by a cam wheel which is fixed to. and
rotated with the driving shaft. This cam wheel carries, projecting from one of its
sides, a pin or stud, which strikes and operates one of the said levers, and on the
opposite side of the said cam wheel are fixed two concentric projecting cam plates;
one plate being used to actuate the second lever: The lower end of the first lever
terminates in a cogged sector, and this cogged sector gears into the cogged wheel,
and actuates it, so as to rock the shaft to which it is fixed, in the desired manner.
A tension spring is fixed by one of its ends to some stationary part of the machine,
or the frame and the other end of the said spring is attached to, or placed in
contact with, the first lever, so as to throw it habitually to one side to the limit of
its movement, thereby rotating the cogged wheel, and with it the rock shaft to
one side, but the tension spring will have sufficient elasticity to allow the first
lever to move to the opposite limit of its movement, as it will do at every revolution
of the driving shaft, by reason of the pin or stud striking the upper end of the
said lever and forcing it to one side. A small projection on the side of the said
lever, next the pin, will form a seat for the said pin to strike against, and the exit
end of this seat will terminate abruptly, so as to allow the lever to drop back
suddenly by means of the action of the tension spring. The length of the seat is
quite short, and the complete forward and backward movement of the lever will
be made between the moment the pin first strikes against the seat and the time
the lever first drops back to its normal position after leaving the said seat.
construction will give to the lever a short, jerking movement, backward and
forward, once at each revolution of the cam wheel, and the consequent rocking
backward and forward of the rock shaft at the same time, thereby giving to the
heok or lifter first an upward movement, and then a downward movement, at
each revolution of the machine, and then the hook will remain lowered at the
same time the tension spring holds the lever stationary, which will be during
seven-eighths (more or less) of the time occupied in one revolution of the driving
shaft. The second lever will be used to move the rock shaft longitudinally in its
seat, and for this purpose the lower end of the said lever will be forked and made
to enter the annular groove, or attached to the collar which may be used in lieu of
the said groove, so as to allow the rock shaft to rotate, at the same time it is held
and governed by the second lever as to its longitudinal movement. The rock
shaft is held habitually drawn in from the front of the machine by a spring,
which is adjustably attached to the rear end of the said shaft by a screw, the
spring being attached to the shaft so as not to interfere with its rotation, or its
This

page_text: forward movement, but of sufficient force to draw the shaft back end wise, to the
limit of its movement, as soon as its forward movement shall have been completed.
The cam plate which operates the second lever is a short curved plate, fixed to the
side of the cam wheel, the curvature of the said plate being concentric with the
cam wheel. The length of this curved plate should be about one-eighth (more or
less) of the circle drawn with the same radius as that describing the curvature of
the said plate, thereby causing the movement of the actuated lever to be made in
about one-eighth of the time (more or less) of the revolution of the cam wheel
and its driving shaft. From the foregoing description of the parts, it is evident
that the second lever will move the rock shaft forward, once, with a short jerky
movement, at each revolution of the machine, and immediately after this move-
ment forward, the spring just mentioned will immediately and suddenly draw the
said shaft and its attached hook rearward. The cam plate, which actuates this
lever, is made with its front end gradually sloping, so as to allow the contracting
end of the second lever to rise up easily on it, as the cam wheel rotates, and the
rear end of the said plate is made to terminate abruptly, so as to allow the, lever
to drop suddenly off the said cam plate, thereby allowing the spring to draw the
shaft rearward, almost instantly, as soon as the lever leaves the working face of
the said cam plate.
"
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113 1111
JJ
115 111
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SO
The combined mechanism above described for operating the rock shaft
constructed and arranged that the said shaft and its hook will first, move forward
toward the front end of the machine, about one inch (more or less,) then the shaft
will rotate and the free end of the hook lift up, so as to grasp the thread in the act
of forming the stitch, as hereinafter explained; then the shaft will be drawn back
by the action of the spring to its normal longitudinal position, carrying the loop of
thread with it, and then the hook will suddenly drop, in the manner hereinafter
explained, in which latter position, i.e. down and back, the book or lifter will
remain during about seven-eighths, more or less, of the revolution of the machine,
and then the above described movements of the hook or lifter will be again
performed. When the hook is drawn back and dropped down, it will drop the
looped thread, forming the stitch, free to the control of other parts of the machine,
and this completed movement of the hook will be performed once at the formation
of each and every stitch sewed on the machine. The shuttle is moved forward and
backward in a reciprocating movement, by means of its operating shaft or bar, to
the end of which it may be directly attached or connected therewith by means of a
connecting bar. The shuttle is driven 'forward by means of its actuating lever,
and is drawn back by means of a retaining spring, which holds the shuttle bar and
its attached shuttle habitually drawn in back from the front end of the machine.
The actuating lever is pivoted to some suitable part of the frame, so as to allow the
said lever to move the shuttle bar forward as required, the lower end of the said
lever being forked and made to engage in a groove, in the said, shuttle bar, or
otherwise attached to the said shuttle bar, so as to readily move it forward as
desired. The upper end of the said lever is engaged with and moved by the second
curved cam plate, which is fixed to the cam wheel, substantially as herein before
described, the whole being operated by the driving shaft, so as to combine the
movements of the shuttle with the other parts of the machine, in order that the
movements of the said shuttle shall be arbitrary and automatic, in combination
with the other mechanisms for forming the stitch produced by this machine.
3
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The shuttle will consist of a cylindrical or flattened bar, sharpened at the end,
and pierced with a transverse hole or eye, the said hole or eye being near the end
of the shuttle, and just inside of the said eye there will be a notch formed trans-
versely in one side of the shuttle, and perpendicular to the axis of the eye. A small,
flat or round spring will be attached securely to the side of the shuttle, one or two
inches, more or less, back from the point of the shuttle, and the said spring will lie
along by the side of and parallel' with the shuttle, but a short distance therefrom,
say one-sixteenth of an inch, more or less, until just at the point of the spring it
19.
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page_text: will touch just in front of the eye, the spring being stiff enough to hold the outer
point of it habitually and with gentle pressure against the side of the shuttle.
The driving shaft, from which all the operative parts of this machine are driven,
will have its. bearings in suitable pillar blocks attached to the frame, and this
driving shaft may be driven by a band wheel placed directly upon it, or by a
cogged wheel and a spur wheel, gearing into the said cogged wheel, and mounted
on a counter shaft. There should be on one of these axles or shafts, a fly-wheel, to
assist in regulating the movement of the machine. The driving shaft may be driven
by power, or by a treadle or other means, as occasion or circumstances may
require.
-
In addition to the wheels or cams already described as being upon the driving
shaft, and the cogged wheel just mentioned, which may be used as a driving wheel,
and which will also act as a crank wheel to a vibrating arm hereinafter described,
there will be placed upon the said shaft, and actuated by it, two other cams herein-
after described more fully.
c
The sewing done by this machine is principally formed by the curved needle.
This needle is fixed to the rotating head, and with it rotates or rocks forward and
backward, in a circular path described from the centre of the hollow needle shaft,
to which the head is attached. The said curved needle is fixed by its central part
to the said rocking head, by means of a small segmental clamping plate screwed
upon it, so as to leave its ends free to perforate or pass through the material being
Bewed. The segmental plate forms a part of the rocking head; to which it is
attached by small screws, which may be withdrawn when a needle is to be removed,
and screwed into place when a needle is to be fastened into the machine. One end
of the said curved needle is sharpened, simply, and is used to pierce the material
being sewed, and the other end is also sharpened to a point, and is also barbed or
notched near its end. In order to stiffen the projecting ends of the needle, while
passing into and through the material being sewed, they are made to pass through
two adjustable guides: These guides are simply two arms, radiating in opposite
directions from, and attached to, the hub band, which is carried on the extreme
outer end of the needle shaft, and is made to rotate with and on the said shaft.
This hub band and its projecting arms are rotated with the said shaft at each one
of its semi-rotations forward and backward, until one of the radiating arms strikes
the projecting jaw, when it will stop, and allow the needle head to continue its
rotary movement to the end of its stroke, thereby pressing the curved needle on
through one of its guides, as the case may be, and allowing the needle to be sup-
ported by the said guide as required, so as to obviate the liability of breaking the
needle, as would otherwise be imminent. During the time the guides are stationary
and guiding the needle ends as above described, and the needle head is moving, the
bub band is allowed to rotate on the needle shaft, or rather the said shaft rotates
within the said hub band, which at other times rotates with the said shaft, the
frictional contact between the said shaft and the said hub band being sufficient to
turn the said hub band when it is left free to turn, but is not too much to prevent
the shaft from rotating within the said hub band, when the band is stopped by
contact of one of the guides, against the projecting jaw, as above explained. The
needle head is segmental in form, and the segmental length of it is about fifty
degrees, more or less, while the arms or guides being radially opposite each other,
the circumferential distance between the said arms is nearly one hundred and eighty
degrees, thus allowing about forty degrees, more or less, for the circumferential
movement of the needle head, which will be amply sufficient to carry the needle
through the thickest work required.
i
The construction of the needle, hereinbefore described, and the movement of the
same, will be arbitrarily as described, and the same will constitute an essential
element and part of the machine under description, but the mechanism for operating
the said needle may be very widely varied, but the subjoined description of the
mechanism will serve as a guide to properly construct and operate the machine.

page_text: The needle shaft, which operates the curved needle, is hollow, and contains
within it a shaft, which has a distinct movement and operation to perform, as will
presently be explained. The said hollow shaft will have its bearings in suitable
attachments to the frame, and it will be long enough to extend the whole length of
the said supporting frame, and overlap it at each end, carrying on its front end the
beforementioned needle head, and at its rear end a cogged pinion wheel which
will be geared into and be actuated by a cogged sector, formed on the lower end of
a vibrating lever, the said lever being pivoted to the rear end of the machine by a
pivot pin.
A crank pin fixed in or to the side of the cogged wheel on the driving shaft
will enter and travel in a slot formed in the upper end of the vibrating lever, and
as the said crank pin rotates around its central-shaft, travelling in the said slot, it
will vibrate the lever or vibrating arm forward and backward as desired, so as to
cause its sector to actuate the cogged pinion wheel, and with it the attached needle
shaft, forward and backward in a rocking movement, about a half a revolution,
more or less, of the said shaft, for the proper operation of the driving head for the
needle as hereinbefore explained.
The small shaft which is placed within the needle shaft, and has its bearings
therein, also has a rocking movement, forward and backward, but at a different
time than is occupied for the movement of the needle shaft. A crank lever or arm
will be fixed to the rear end of the said small shaft, which will project beyond the
end of the needle shaft on that end, far enough to allow for the attachment
of the said lever or arm. A connecting rod will connect the lower end of the arm
with the lower end of its actuating lever, the latter lever being fulcrumed to the
frame by a pivot pin, and actuated or moved forward by a cam on the driving
shaft, coming in contact with the said lever or with a pin projecting therefrom,
and then a spring will draw the actuating lever back to its normal position as soon
as the said pin shall have been released from a projecting part of the said cam.
The projecting part of the said cam which moves the actuating lever forward, will
occupy about one-eighth, more or less, of the circumference of the cam, and a
depressed or smaller diametered part of the said cam will consequently form about
seven-eighths, more or less, of the circumference of the said cam face, and as the
spring will draw the lever back with a smart jerk as soon as it leaves the projected
face, it is evident that the movement communicated to the small shaft through the
intermediate connections will be a short, jerky, rocking movement of about one-
eighth of a revolution, more or less, of the small shaft, at each revolution of the
driving shaft, and this quick movement forward and backward will be communi-
cated to the curved stitch guide, which is attached to the guide head, forming the
front end of the enclosed small shaft. The use of the stitch guide will be to
measure and form one of the interlocking loops of the stitch, as will be hereinafter
more fully explained.
The movement of the stitch guide will be arbitrary, as must all of the essential
features of the machine; but the method of producing this movement can of course
be obtained by various mechanical devices, though those herein described are
deemed best. The stitch guide will be a sharp-pointed steel wire of about the same
size as the needle, perforated with a thread eye, and from the point of it, it will be
curved around for about a half a circle, more or less, on the same length of radius
as that which would describe the curvature of the needle and when this stitch
guide is fixed to its driving head, it will stand in a plane parallel with that
occupied by the needle, and about one-eighth or one-quarter of an inch, more or
less, distant therefrom, as may be required to form the length of the stitch loop
desired, and this distance of the loop-former from the needle may be regulated at
will, to suit different work, by sliding the small shaft endwise in its enclosing shaft,
and securing it in the proper position by one or more adjustable collars on the said
small shaft, and for this purpose the rocking arm or lever may be used as a
retaining washer, and set adjustably to the said small shaft by means of a set screw.
The small shaft with its attachments, may also be set adjustably to rotate more or

page_text: less as may be desired, by moving a wrist pin that connects the connecting bar
with the crank arm or lever, up or down in a slot in the said arm, thereby
lengthening or shortening the stroke of the said connecting crank pin, and
consequently making the rotation of the small shaft more or less, as desired.
The tension arm that draws the stitches tight in the seam sewed, is another
principal feature of this machine.
A shaft, like all other operative parts of the machine, has its bearings in the
frame, or in some suitable attachment thereto, and it, like the rock shaft herein-
before described, will have, in addition to a rocking movement, a sliding movement
longitudinally, the rocking movement being communicated to it by a cam, cam,
arm, and a retaining spring, and the longitudinal movement by one of the cam
wheels, above described, with its cam groove or face, and two levers, which are
fixed respectively to the upper and lower ends of a rocking post, the latter being
mounted on and rotated around a fixed vertical axle, which is also fixed to the
frame, a lateral arm being used as an intermediate support, and secured firmly
to the frame, so as to allow the base of the rocking post to rest on top of the said
supporting arm. As both the cams are fixed to and driven by the driving shaft,
from which all the other operative parts of the machine are driven, it follows
that the shaft just mentioned and the arm moved by these said cams will move
arbitrarily and in combination with the parts already described.
The spring holds the rock shaft just mentioned habitually so as to throw the
arm down into a certain position, in which position the lower part of the said arm
will rest against a stop, which is fixed to and projects from the frame. This will
be the limit of the downward movement of the said arm and the spring that moves
it into and holds it in that position is fixed to a vertical post of the frame, and the
other end of it is fixed to the cam arm. One of the cams attached to the driving
shaft is slightly more than a quadrant of a circle, terminating in two abrupt lines,
at its respective ends, the said end lines forming the cam being nearly radial from
the central hub by which the said cam is fixed to the driving shaft. By this
construction of the said cam, the front face of it, will first strike the cam arm and
suddenly throw it up to the full limit of its stroke, thereby causing the tension
arm to suddenly fly up, and this sudden and forcible throwing up of the tension
arm will draw the stitch or thread forming the stitch up tightly into the material
being sewed as will be presently more fully explained. From the moment the cam
arm first attains the full limit of its stroke by reason of the extreme outer end of
it reaching the curved periphery of the cam, as the said cam revolves, the said arm
will be held stationary for a moment, as well as the connected shaft, and the
tension arm, by reason of the end of the said cam arm being held stationary on
and by the curved periphery of the cam until the abrupt terminal end of the cam
shall come round and allow the cam arm to be suddenly drawn back to its normal
position by the spring. At this sudden, almost instantaneous action of the spring,
the tension arm will be drawn down to its normal position of rest upon a projecting
pin or stop, and there remain ready for the next stroke forward, and so on, the
strokes or vibrations of the tension arm will be repeated and continued, forming or
tightening a stitch at each revolution of the machine.
In addition to this rocking movement of the shaft, and the vibrating movement
of the tension arm, the said shaft and arm will also have a reciprocating movement
forward and backward, about a quarter or an eighth of an inch, more or less, at
each stroke of the machine, as has before been mentioned. This reciprocating
movement of the tension arm and its actuating shaft, will be for the purpose of
carrying the thread forming the stitch into the barb of the needle, as will be
presently explained.
The shaft has a slot cut circumferentially in it, and this slot will be engaged by
the forked end of one of the arms or levers, which radiates or projects horizontally
from the vertical rocking post, and which said post moves the said arm backward
and forward as required, the said post being rocked in the desired manner by the
other horizontal arm or lever, the free end of the last named arm or lever being

page_text: engaged in and moved by the groove or cammed surface of one of the cam wheels;
the whole operating in combination with each other and with the driving shaft,
from which they are driven, so as to produce the desired reciprocating movement
of the tension arm, and also this movement arbitrarily in combination with the
movements of the other parts of the machine.
The outer end of the tension arm is curved downwardly, and a notch in its
extreme end forms that part into a long, slim, extreme tip, and an inner tip of
larger dimensions; the latter tip being perforated with an aperture, and through
this aperture the thread used from one of the spools, is passed to the curved needle
a small sheave being used to run the thread over into the hole. When the tension
arm is thrown down to the lower limit of its movement and the needle is rotated
so that its barbed end will pass through the material being sewed, the continued
rotation of the needle to the end of its stroke, after having passed through the
material being sewed, will carry the end of it far enough into the notch, which
will then overlap the needle point, to allow the thread to drop into the barb, and
just at the moment that the thread thus overlaps the barb, the tension lever or
arm will be moved laterally by its reciprocating movement above described, and
thereby carry the thread into the barb, so that it must be certainly drawn back by
the next semi-rotation of the needle, and carried along with it into and through
the substance of the material being sewed.
A small vibrating arm, two or three inches in length, more or less, is pivoted to
the side of the tension arm toward its outer end, by a pivot pin, and when the
tension arm is in its lower position the vibrating arm will stand in nearly a
vertical position, and in this position it will be held by a stop (in the side of the
tension arm) against which it strikes, and the tension spring attached by one of its
ends to the top end of the said vibrating arm and by its other end to a ring fixed
to the hub of the tension arm on the top of its shaft. This arrangement of the
spring will draw the vibrating arm into a downward position and yet permit it. to
assume a raised position when it or its attached arm strikes a stop and guide, in
the upward movement of the tension arm; the said stop and guide piece being fixed
securely to some part of the frame for this purpose. The stop or guide has a
projecting horizontal arm, from the inner side of which projects a short lug.
The small arm attached to the rear side of the vibrating arm is simply constructed
of a bent wire, one-eighth of an inch, more or less, in diameter, and curved over to
the rearward of the said vibrating arm, from which it projects two or three inches;
more or less, so as to form an attachment for a small coiled spring, which will
connect the rearmost projection of the small arm with the outer end of a vibrating
button, which is pivoted to the lower end of a rod, as presently explained.
To the outer end of the rocking shaft, and outside of the tension arm there will
be movably attached a small radial arm, and an angular projection, attached to.or
formed on the extreme outer end of this arm will have a central longitudinal slot
for the passage of the thread to the needle, as hereinafter explained. As the
rocking shaft rotates or rocks backward, so as to let the tension arm fall down to
its lowest position, the projecting radial arm will fall with it as far as the projecting
lug of the horizontal arm above referred to, on which it will catch and stop for a
moment, while the tension arm proceeds on in its downward movement, but this
stop of the radial arm on the lug will only be for a moment, for just at that instant
the inward longitudinal movement of the rocking shaft will commence, and by it
the radial arm will be released from its hold on the stop or lug, and it will then
continue its downward movement until it stops at the lower limit of its movement
in a position parallel with the tension arm, or nearly so. The button, before
alluded to, is a small projecting arm pivoted to the bottom end of the vibrating
arm. A spring is attached to this button or arm so as to hold it habitually in a
longitudinal line parallel with the axis of the needle shaft, but the said spring will
also allow the projecting or free end of the said piece to fly back, which it will do
every time the tension and vibrating arms are raised up, by reason of the projecting
end of the button coming in contact with the sewing thread, while the said thread

page_text: is drawn tightly between the work in the jaws, and the slotted end of the radial
lever, when caught on the lug. The spring will also allow the projecting end of the
button to swing forward, which it will do in the following manner. When the
tension arm is being lowered toward the needle, so as to permit the thread to be
engaged by the barb of the said needle, the thread will be drawn across the notch,
in the end of said arm, and rest against the ends of both the projections, and at
this part of the stroke the free end of the button will be in front of and hold the
thread taut against the said projections, and thus render the said thread certain to
be caught by the barb of the needle, when the said needle end enters the notch
beyond the thread line; but the moment the motion of the needle is reversed, the
thread having been caught in the barb, will be drawn against the projecting end
of the button, and thereby swing it round on its pivot, the spring yielding at that
moment, for this purpose, and immediately after the end of the button shall have
thus passed the thread the tension arm will be freed from any impediment to its
upward movement, and it will consequently proceed in its movement from the
lower position, to the upper position, and simultaneously, with this upward
movement of the tension arin, the button will resume its normal position, impelled
thereto by the action of the said spring. In this manner the said button will hold
the thread upon the ends of the projections, during the downward movement of
the tension arm with its attachments, and thus extended across the opening, the
thread will catch on the barb of the needle on its entering the said notch, and then
as the needle is rotated backward it will carry a loop of the thread along with it
into the material being sewed; and the forward end of the button with spring
forward far enough with the thread to allow the thread to slip off the end of the
said button, and in this manner the operation, of the machine will be continued,
the button holding the thread on the lips at every stroke of the tension arm, so as
to insure the thread catching on the needle.
At every upward movement of the tension arm it will carry with it the thread,
so as to draw the said thread tight in the seam being sewed, and during this
tightening of the sewing the thread will draw back into the seam, along with it,
another thread, the latter being in the form of a loop interlocking the loop formed
by its thread, and during this movement of the tension arin, the first named thread
being held from feeding out at its spool end, will draw over the loop of the second
named thread in the seam, so as to tighten upon it, the first thread running back
in the movement, so as to tighten upon the loop of the second thread in the seam,
by reason of the first thread being drawn back with and by the tension arm.
A ratchet, hereinafter described, will at each rotation of the machine feed out
a sufficient quantity of the first thread to form one stitch or loop; and in order to
prevent the thread so paid out forming too large a loop on the barb, or the barb
catching other than in the centre of the loop, and consequently being run back to
the proper length over the said barb, thereby abrading the thread. The swinging
radial arm will be employed to measure and divide the thread so that each
individual loop formed of the first thread will be of equal and uniform length, and
the centre of each loop, caught squarely on the barb. The attachment of this arm
to the rocking shaft will be by means of a frictional band, which will surround the
end of the said shaft, and be moved therewith simply by frictional attachment, but
which will also permit the said shaft to turn within the said band; thus the radial
arm will move with the rocking shaft when the tension arm commences to move
downwardly, but it will stop in its downward movement a moment when the
radial arm strikes the stop, and allow the shaft to continue its partial rotation,
thus moving on the said shaft, as well as with it. While the radial arm is held
on the stop, it will draw back the slack of the thread, passing through its slotted
end, and thereby divide the thread, or rather the loop formed on it, so that the
loop will be of the proper length, and the centre of the loop will be caught on the
barb as desired..
The two principal threads with which the seams of this machine are sewn are
carried on two spools, and the auxiliary thread is carried on a third spool. All of

page_text: these spools are suitably pivoted on the machine, so that the threads may readily
unwind therefrom.
.
The first thread, from the first spool, is wound around a feeding drum which is
moved by the ratchet just referred to, a pawl, and a lever, so as to feed out a
certain required amount of thread at each revolution of the machine. The drum
and ratchet will be mounted on an axle, which is fixed to and projects from the
frame. The lower end of the actuating lever is also engaged by the axle or pivot
pin, which forms the fulcrum of the said lever. The upper end of this actuating
lever is guided by the projecting arm of a lateral cam hereinbefore mentioned, the
said projecting arm being slotted for the reception of the said actuating lever, and
thereby forming a stop for the limit of its forward movement, as well as a lateral
guide and stay for it.
The actuating lever will be habitually thrown forward on its operating cam by
means of a spring, which is fastened by one of its ends to some stationary part,
and arranged to allow its free end to press forward against the actuating lever.
This lever will be moved forward once at each revolution of the machine, by means
of a special cam, or by a pin projecting from the side of the cam wheel first
mentioned. A pawl, pivoted or fulcrumed to the said lever, has a spring which
habitually presses it into or against the teeth of the ratchet wheel, and as the
lever is moved forward by the cam pin, the ratchet wheel and its attached spool
or feeding drum will be turned around far enough to feed the first thread (which
passes from the first spool to the vibrating tension arm) out enough to form one
stitch. A suitable retaining pawl or dog, may also be fitted against the ratchet
wheel, to hold it against a rearward movement while the pawl is being moved back
for a new hold.
The first thread will pass from its spool once or twice, or more, around the
feeding drum, and thence through a slot in the outer end of the feeding arm,
and thence down through the aperture in the outer end of the tension arm,
from which it will pass to the needle, the hook or barb of which needle will catch
this thread and draw it through the work with the backward rotation of the said
needle. The method of measuring the thread to form this loop or stitch will be
presently explained.
The second thread which is unwound from its spool is passed forward through
the eye of the shuttle; and when the said shuttle is shot out to the full limit of
its stroke, the notch will be placed just below the point of a stitch guide, and
then this stitch guide or hook will turn down into the said notch, thereby catching
the loop of the thread, and holding it at a certain fixed length through the loop
of the first thread, which at that moment will just have been drawn through the
material by the backward rotation of the needle. In its forward movement, the
shuttle will pass through the loop of the first thread, held on the barb of the
needle, and by catching the loop of the second thread on the hook, each and every
loop of the said second thread will be accurately measured, and the sewing will be
smooth and perfect on both sides of the work. When the stitch guide is thrown
down into the notch of the shuttle, and into the loop of the second thread, it will
carry along with it the auxiliary thread, and unite it with the first and second
threads, and so form the three threads into one stitch or combination of loops,
the shuttle drawing back the loop of the auxiliary thread with it, so as to
interlock the loop of the said thread with the loops of the other two threads.