Improvements connected with Boot and Shoe Sewing Machines.
Year: 1894

page_text: Date of Application, 17th Sept., 1894
Complete Specification Left. 17th July, 1895-Accepted, 14th Sept., 1895
PROVISIONAL SPECIFICATION.
Improvements connected with Boot and Shoe Sewing Machines.
We, GEORGE HARRY SCETRINI, of 1 Lesley Street, Barnsbury, London,
Mechanic, and HERBERT KYNASTON BRIDGER, of 2 Danes Inn, Strand, County
of London, Gentleman, do hereby declare the nature of this invention to be as
follows:-
This invention relates more particularly to lock stitch sewing machines but some
of the improvements hereinafter enumerated are applicable to chain and other
stitch machines used for sewing boots and shoes.
It consists 1st. In the particular method and arrangement of the respective parts
for locking the presser foot down upon the work to hold it firmly in position upon
the table during the piercing and stitch making operations, and moreover to
accomplish this in such a manner that it can only be released by the action of a
cam on the driving shaft or by a hand lever suitably connected. When released
by the cam it automatically accommodates itself to any inequality or varying
thickness of work with absolute certainty and ease, the locking at the same time
being effected in an efficient and novel manner without the use of ratchets or
gripping or jamming devices as heretofore employed for the purpose. 2nd. In
the particular formation and disposition of the shuttle hook and shuttle respectively
whereby the loop as it is drawn through the work is withdrawn from the needle
barb without necessitating a second motion of the said needle, this being accom-
plished by means of a wing forming part of the shuttle hook acting as a guide
or cast off by advancing the thread down the needle, and so withdrawing the
thread from under the barb. 3rd. In the adaptation and arrangement of a curved
spring lever or automatic relief catch in the path of the loop for it to become
engaged thereon as it is drawn over the shuttle by the take up, and be so held
back that the thread is left of sufficient length for the following loop to be pulled
through the work by the needle without see-sawing the thread through the barb,
thus preventing the chafing and cutting action common to existing machines.
4th. So arranging the various parts and timing the movements relatively to the
"take up" that the stitch is pulled in and tightened by the shuttle hook instead
of by the "take up."
In carrying out our invention under the first head we provide that the presser
foot be moved forwardly simultaneously with the work to assist the awl in the
feed, and so connect the presser leg to the levers intermediately arranged between
it and the actuating cam on the driving shaft that it can move freely downwards
upon the work to hold it in position but cannot be lifted by the application of any
force at the presser foot.
Any release or upward movement of the foot can only be obtained under the
action of the cam or of a lever suitably connected, as hereinafter described.
A rack is formed on one side at the top of the presser leg which gears with a
quadrant pivoted at a given point intermediate of its ends to the machine. At
the end opposite to that of the quadrant is connected a link, the other end of
the link being pivoted to one end of a slotted bar arranged at a given angle
thereto.
This slotted har is carried by and slides upon pins projecting from one arm of
a bell crank which is suitably connected to the machine frame. The other arm of
the bell crank engages with the cam on the driving shaft.

page_text: Inasmuch as the direction of motion of the slotted sliding bar is at approxi-
mately right angles to that of the presser foot and connecting link, and the bell
crank arm is in contact with the cam, no upward motion can take place of the
presser leg, but if on the contrary the slotted bar is caused to slide on the bell
crank arm by a lever, or the bell crank itself alters its position by means of the
cam, tension may be put upon the connecting link to draw down that end of the
quadrant lever, and so raise the other and with it the presser foot.
The presser leg has a free vertical movement under the action of the above
mechanism in a horizontal sliding bolt but is moved horizontally thereby under the
action of a lever pivoted to the machine frame which in turn is operated by link
connected to one end of a rocking lever, the other end being oscillated by a cam
on the driving shaft. The amount of said horizontal movement is regulated by
adjusting the connecting link in a slot of the rocking lever a given distance from
the centre.
According to the second part of our invention the shuttle hook is bifurcated or
formed with a wing piece which curves backwardly at a different arc to that of
the travel of the hook whereby the loop as it is drawn down by the shuttle hook
is widened out and advanced down the needle and so drawn from under the barb
which at this time is entering the bifurcation of the book.
The loop having been disengaged from the barb is carried round by the shuttle
hook to its farthest extremity and in so doing draws upon the previously formed
loop to tighten the stitch, this being effected by the shuttle and not by the "take
up.' The loop is then disengaged from the shuttle and the "take up" draws
upon the thread and makes the loop smaller until it catches upon a spring pivoted
lever or relief catch arranged in its path, and by which it is held until drawn off
by the passage of the thread through the work by the barb when forming the
loop for the succeeding stitch.
The amount of thread in the loop retained by the spring lever or relief catch
and that drawn off the reel by the looper is just sufficient to ensure about an
equal amount of slack thread on each side of the barb, so that the thread on being
drawn through the work to form the loop is not moved in the barb at all, thereby
preventing any chafing or tearing of the thread.
To enable the bifurcated hook to more readily enter the loop we preferably
arrange the shuttle race at an angle for it to advance as it were upon the needle
during its entry into the loop, and recede therefrom at its hindmost position to
free the threads from contact with the needle.
Dated thin 17th den
Custom 1004
H. GARDNER,
Patent Agent, 166 Fleet Street, London,
Agent for the said G. H. Scetrini and H. K. Bridger.
™
H. GARDNER,
Patent Agent, 166 Fleet Street, London,
Agent for the said G. H. Scetrini and H. K. Bridger.
COMPLETE SPECIFICATION.
Improvements connected with Boot and Shoe Sewing Machines.
We, GEORGE HARRY SCETRINI of 1 Lesley Street, Barnsbury, London,
Mechanic, and HERBERT KYNASTON BRIDGER of 2 Danes Inn, Strand, County
of London, Gentleman, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
This invention relates more particularly to lock stitch sewing machines, but some
of the improvements hereinafter enumerated are applicable to chain or other stitch
machines used for sewing boots and shoes.
It consists first in the particular method and arrangement of the respective parts
for locking the presser foot down upon the work to hold it firmly in position upon

page_text: the table during the piercing and stitch making operations, and to accomplish this
in such a manner that it can only be released by the action of a cam on the driving
shaft or by a hand lever suitably connected; and moreover that the presser foot
when released by the cam can automatically accommodate itself to any inequality
or varying thickness of work with absolute certainty and ease, the locking at the
same time being effected in an efficient and novel manner, without the use of
ratchets or gripping or jamming devices as heretofore employed for the purpose.
2nd. In the particular formation and disposition of the shuttle hook and shuttle
respectively whereby the loop as it is drawn through the work is easily withdrawn
from the needle barb, this being accomplished by means of a wing forming part of
the shuttle hook acting as a guide or cast off by advancing the thread down the
needle and so withdrawing the thread from under the barb.
3rd. In the adaptation and arrangement of a curved spring lever or automatic
relief catch in the path of the loop for the loop to become engaged thereon as the
loop is drawn over the shuttle by the take up and be so held back that the thread
is left of sufficient length for the following loop to be pulled through the work by
the needle without see-sawing the thread through the barb, thus preventing the
chafing and cutting action common to existing machines.
4th. In so arranging the various parts and timing the movements relatively to
the take up, that the stitch is pulled in and tightened by the shuttle hook instead
of by the take up.
Our invention will be fully understood upon reference to the annexed three
sheets of drawings in which:-
Fig. 1 is a side elevation of the parts of a boot sole sewing machine, constituting
our invention.
Fig. 2 is a reverse side sectional elevation.
Fig. 3 is a plan of the parts connected with the presser foot, the other parts of
the machine being left out in order to render the invention more clearly.
Figs. 4 and 5 are front views illustrating the two positions of the plate in which
the presser leg has its up and down movement, and by which it is moved laterally
at the time the work is fed by the awl.
Fig. 6 is a sectional plan of the presser foot front plate more particularly
showing the recess for receiving the presser leg and the hole by which the plate
is moved.
Figs. 7 and 8 are front elevation and side sectional elevation (inverted)
respectively of the shuttle showing the form of hook and loop catch and angular
position of the shuttle preferred when used in conjunction with our improved
presser foot feed.
Figs. 9 to 18 inclusive are views illustrating the various positions the mechanical
parts occupy during the formation of a complete stitch, the development of the
stitch being clearly shown by the diagram against each figure.
gears
The presser leg 2 formed at its upper end with rack teeth 1
with a
quadrant lever 3, pivoted at 4 to the lug 5, on the top of the machine frame. The
quadrant lever 3 is connected by a link 7 to the end of a sliding bar 8, which is
acted on by a spring 14, tending to force it upwards and so to lower the presser
foot towards the work, and is arranged at such angle to the link that a very
considerable force must be transmitted through the link before the bar slides
downwards against the resistance of friction and the spring. A stop 3* limits
downward motion of the presser foot.
The sliding bar 8 is slotted and works on two pins 10, 10*; one 10 projecting
from one arm 11* of a bell crank 15 and the other 10* being fixed in the frame
and serving as a pivot for the bell crank 15. The other arm 11* of the bell
crank 15 carries a roller 16, working in the race of the cam 17. The spring 14
tends to force the sliding bar longitudinally upwards in the opposite direction to
the arrow.
When the roller 16 passes into the depression 18 in the cam race 17, the bell
crank 15 and sliding bar 8 take up the position shown in dotted lines in Fig. 1, the

page_text: When the
presser foot being raised to allow of its return lateral movement.
presser foot is in this position and the resistance to its downward motion is removed
by the presser foot being withdrawn from the work, the spring 14 forces the bar 8
in the opposite direction to the arrow as to ensure that when next depressed it
shall come down firmly on to the work. When the roller 16 rises out of the
depression it forces the presser foot down on to the work until the pressure of the
foot on the work attains a certain amount. If this amount of pressure is attained
before the roller has completely risen out of the depression in the cam, the
resistance of the presser foot to further notion causes the bar 8 to slide in the
direction of the arrow so as to prevent under the action of the cam further down-
ward motion of the presser foot and consequent increase of pressure. The presser
foot thus automatically adjusts itself to the thickness of the work. The pressure
of the presser foot is thus practically always the same and depends principally on
the friction of the bar 8 on its pins and to a lesser extent on the strength of the
spring 14.
Normally whilst the stitch is being formed or the work being fed the parts
occupy the position shown in full lines in Fig. 1, and any pressure exerted on the
presser foot whilst the awl or needle is piercing the sole, is transmitted directly to
the cam 17, so that the sole is held rigidly as such pressure is not sufficient to cause
the sliding bar 8 to slip back in the direction of the arrow on the pins 10, 10*.
The function of the spring 14 is practically to force the sliding bar 8
longitudinally forwards when the presser foot is raised from off the work so that
even when working from thick to thin it shall always be brought to bear on the
leather with the desired pressure; but it is also desirable to reduce this motion to
the smallest amount consistent with the efficient working of the machine, so as to
render the working of the machine more smooth and to reduce the wear on the
sliding bar and its guide pins. This forward movement which should be sufficient
to compensate for slightly more than the greatest decrease in thickness in the
leather to be sewn that is likely to occur in practice from one stitch to the next
depends on the speed of the machine, the inertia of the parts to be moved and the
strength of the spring 14. To regulate the amount of this forward motion the
inertia of the parts can be increased to the requisite degree by means of a weight.
acting on the bar in a suitable manner.
.
This is conveniently effected by a weighted hand lever 13, that can also serve to
raise the presser foot by hand, for example, when inserting or removing work.
The hand or bell crank lever 13 pivoted to the frame has a slot engaging with the
pivot 22, connecting the link 7 to the sliding bar 8. On depressing the knob 38
on end of the lever 13 to the position shown in full lines in Fig. 2, the bar 8 is slid
on the pins 10 10* to the position shown and raises the presser foot. On releasing
the lever 13, the spring 14 causes the presser foot to again descend. Any action
of the spring to move the sliding bar upward has to overcome the inertia of the
weighted band lever. The amount the sliding bar is moved forward by the spring
after each stitch, which as before stated, depends on the velocity of the machine
and the inertia of the parts is in practice so small that it can barely be seen.
The teeth of the quadrant 3 are of sufficient width to allow of the lateral
movement of the presser foot during the feed and withdrawal motions.
In order to move the presser foot forward simultaneously with the awl to assist
the awl in feeding the work, the presser foot 2 is mounted in a groove in a carrier
plate 26 adapted to slide in the main frame and operated from the cam 27 on the
driving shaft through the lever 28, and link 29, by a lever 30 whose end engages
in a hole 31 in the plate 26. The quadrant slot 32 enables the extent of the
traverse of the plate 26 to be adjusted to correspond with that of the awl. In
order to traverse the awl simultaneously with the presser foot, the awl carrier 24 is
fixed on the shaft 25 which is slid end wise in its bearings to traverse the awl by
means of the cam 33 on the driving shaft through the quadrant lever 34 connecting
link 35 and fork 36. The traverse of the awl is adjusted by means of the quadrant
Laver 34

page_text: The rotary shuttle 42 works in the race 52, and is rotated by means of the pin 53
fixed in a toothed wheel 54, driven from the toothed wheel 55, through the
intermediate wheel 56, so that the shuttle makes a double rotation for each rotation
of the main shaft, but only engages the loop at each alternate rotation.
In order to widen out the loop and withdraw it from the barb of the needle, the
shuttle hook is bifurcated and formed with a wing 41, which curves from the point
of the hook outwardly and backwardly approaching nearer to the centre of the
shuttle. The wing as the shuttle hook passes up the loop widens out the loop and
advances the thread down the needle to disengage it from under the barb which is
in the bifurcation of the hook as shown more particularly at Fig. 16. The shuttle
then draws upon the thread to pass itself through the loop to entwine the shuttle
thread to form the lock stitch, and in so doing pulls upon the previously made stitch
to tighten it and draws through the tension device any extra thread required. The
take up now comes into action to partially draw up the loop, the thread being held
perfectly tight by any suitable device.
In order to retain after each stitch is taken up sufficient thread to form one side
of the loop and obviate chafing in the barb of the needle, a spring relief hook 46 is
arranged in the path of the loop and upon which the loop is caught and retained,
the amount of thread so retained by the relief catch 46, and that drawn off by the
looper 47 in the ordinary way, is just sufficient to ensure the amount of thread
required on one side of the loop when drawn through the work by the barb needle,
the thread required to form the other side of the loop being obtained by the
downward movement of the take up which occurs simultaneously with the downward
movement of said barb needle.
The relief hook 46 is pivoted to a lug 48 cast on the shuttle box 49, and has
a horn 50, to which is attached a tension spring 51 to allow a yielding action of the
hook 46.
The shuttle is arranged at an angle as shown at Fig. 8 for it to advance as
it were upon the needle during its entry into the loop and recede therefrom
at its hindermost position to free the thread from contact with the needle.
The operatious involved during the formation of a complete stitch will be clearly
understood by the following description with reference to Figs. 9 to 18.
In Fig. 9 the loop 57 of the previous stitch is held by the relief catch 46 and the
awl 24 about to pierce the work, the needle 44 being at its lowermost position.
The state of the stitch is shown at A, the loop and locking thread being designated
by like numerals throughout the respective diagrams.
Fig. 1 is a front view of Fig. 9, and shows the relative position of the looper 47
at this stage.
In Fig. 11 the awl 24 has pierced the work and moved it sideways for the hole
to be immediately above the needle 44. The awl 24 then lowers and retires
sideways and the needle 44 passes up through the hole and the looper 47 revolves
and draws the thread 58 across the needle 44 and under the barb 45, as in Figs. 12
and 13 in which the awl is not shown to avoid confusion and the shuttle 42 has
completed the first half of its idle revolution. The amount of thread a b c is just
sufficient to form one side of the new loop when the needle has fully drawn it
through the work.
Fig. 14 represents the new loop drawn through the work by the needle barb 45
nearly to the end of its stroke, the looper 47 meanwhile having returned to its
normal position and allowed the slack thread to follow the barb in the ratio
required, the extra amount necessary for the completion of the loop being drawn off
the relief hook 46 up through the previous hole in the work and down the new hole
in the direction represented by the arrows in the diagram Fig. 144. The shuttle 42
bas completed three-quarters of its idle revolution and the retained loop is all but
drawn off the relief hook 46 which has yielded under the pull of the needle 44.
In Fig. 15 the needle 44 has fully drawn the loop, and it is to be understood that
the take up has moved downwards sinultaneously with the needle and thus

page_text: supplies sumcient slack thread in the ratio required to form the other side of the
loop.
In Fig. 16 the hook 40 has entered the loop and the needle 44 is in the
bifurcation of the hook, the manner in which the wing 41 advances the thread
down the needle stem 44 to disengage it from under the barb 45 being clearly
shown.
In Fig. 17 the shuttle 42 has completely drawn the previous stitch tightly into
the work, and drawn off the reel the extra quantity of thread it required which is
now being taken in by the take up, the figure clearly showing how the loop is
drawn under the driving pin 53 and between the lump 58 on the spool carrier 59 and
the fork 60 for it to entwine the locking thread 61, and in Fig. 18 the loop is
just about to be drawn clear of the shuttle by the take up and be retained by the
relief catch 46, just previous to the uprising of the needle 44 to fetch another
loop.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. In a boot and shoe sole sewing machine the means for operating and imparting
the required pressure to the presser foot whatever the thickness of the work,
consisting of a cam, of mechanism for transmitting the motion of the cam to the
presser foot, and of a sliding piece in the said mechanism adapted to transmit the
required motion and to slip in its guides when the resistance to the motion of the
presser foot attains the required amount to prevent further motion of the presser
foot and to tend to return to its normal position when the said resistance is removed,
substantially as described.
2. In a boot and shoe sole sewing machine the means for operating and imparting
the required pressure to the presser foot whatever the thickness of the work,
consisting of a cam, of mechanism for transmitting the motion of the cam to the
presser foot, of a sliding piece forming a member of the said mechanism and
transmitting the motion at an angle to the direction of its slide so that when the
resistance to the motion of the presser foot attains a certain amount it slides in its
guides and prevents further motion of the presser foot, and consequent increase of
its pressure, and of a spring tending to return the sliding piece to its normal
position when the said resistance is removed substantially as described.
3. In a boot and shoe sole sewing machine, the means for operating and imparting
the required pressure to the presser foot whatever the thickness of the work,
consisting of a cam, of mechanism for transmitting the motion of the cam to the
presser foot, of a sliding piece in the said mechanism adapted to transmit the
required motion and to slip in its guides when the resistance to the motion of
the presser foot attains the required amount to prevent further motion of the presser
foot and consequent increase of its pressure, of a spring tending to return the
sliding piece to its normal position when the said resistance is removed, and
of a counterweighted lever opposing the motion of the spring substantially as
described.
4. In a boot and shoe sole sewing machine, the means for operating and imparting
the required pressure to the presser foot whatever the thickness of the work
consisting of a cam, of mechanism for transmitting the motion of the cam to the
presser foot, and of a sliding piece in the said mechanism adapted to transmit the
required motion and to slip in its guides when the resistance to the motion attains
the required amount to prevent further motion of the presser foot and consequent
increase of its pressure, of a hand lever for operating the sliding piece to raise the
presser foot by hand and of a means tending to return the sliding piece to its
normal position when the resistance is removed, substantially as described.
5. In a boot and shoe sole sewing machine, providing the shuttle hook with a
wing curving outwardly and backwardly approaching nearer to the centre of

page_text: rotation of the shuttle for the purpose of advancing the thread down the needle to
release it from the barb in the manner as described and shown.
6. In a boot and shoe sole sewing machine, in which the usual take up leaves
sufficient thread to form one side of the next loop to be presented to the shuttle,
spring hook arranged in the path of the loops as they are drawn off from the
shuttle to retain the required amount of and hold open the loop substantially as
described.
7. In a boot and shoe sole sewing machine, the method of performing the take up
to obviate drawing the thread through the barb, consisting in a partial take up at
the ordinary time to clear the loop from the shuttle to leave it free to make its idle
revolution, in taking up a portion of the remaining slack thread during the
formation of the next loop to form one side of the loop, and in completing the
take up on the passage of the shuttle and locking thread through the said next loop
substantially as described.
Dated this 17th day of July 1895.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.