IMPROVEMENTS IN SEWING, for an MACHINERY, CHIEFLY DESIGNED FOR THE MANUFACTURE OF BOOTS AND SHORS
Year: 1880

page_text: LETTERS PATENT to William Henry Dorman, of Stafford, in the County of
Invention of "IMPROVEMENTS IN SEWING
Stafford, Engineer, for an
MACHINERY, CHIEFLY DESIGNED FOR THE MANUFACTURE OF BOOTS AND
SHORS"
PROVISIONAL SPECIFICATION left by the said William Henry Dorman at
the Office of the Commissioners of Patents on the 12th November 1880.
WILLIAM HENRY DORMAN, of Stafford, in the County of Stafford, Engineer.
"IMPROVEMENTS IN SEWING MACHINERY, CHIEFLY DESIGNED FOR THE MANU-
FACTURE OF BOOTS AND SHOES."
My Invention relates to that class of sewing machinery, chiefly designed to be
employed in the manufacture of boots and shoes, in which a curved needle is used,
and which works with a single thread, such machinery being utilized principally
for stitching the sole to the welt, or whatever part may be used in place of a
welt.
The object of my said Invention is to provide this class of sewing machinery
with mechanism for varying, in proportion to the thickness of the material being
sewn, the length of the loop of thread drawn up by the needle.
According to my Invention this variation is obtained by providing means
whereby the fulcrum of the lever that gives or transmits motion to the needle may
have a limited movement, so as to absorb a certain part of the motion that would
otherwise be imparted to the needle, this movement of the fulcruin being regulated
by connecting the mechanism that determines the amount or extent thereof, with a
pressure-piece in contact with the surface of the material to be sewn in such a
manner that the thickness of the said material or work shall regulate the movement
of the said fulcrum.
In carrying the said Invention into practice, when applied to a machine of the
class known as the "New Goodyear Stitcher," the needle is attached to and works
with a toothed segmental carrier which is operated by a similar segment on the
end of a lever in the usual manner. The fulcrum of this lever is carried upon a
pillar standing in an inclined position in such a manner that its centre line is
tangential, or nearly so, to a circle struck from the centre of the pivot of the needle
carrier or stock. It is free to move in the direction of its length in guides carried

page_text: on a post fixed to the frame of the machine, and in order that it may move with
freedom the principal part of its weight is taken up by a spring. The aforesaid
pillar is provided with a collar so placed that when the pillar has been raised as far
as may be required by the revolution of the needle-cam it will take against the
underside of a bearing and arrest further movement. This collar is made
adjustable to a small extent so as to allow, in adjusting the machine, of bringing
the edge of the needle-carrier or stock, when at its lowest or most forward point, to
the most convenient distance from the surface of the work. A friction cushion is
provided to offer the necessary resistance to the seginent-lever. Underneath the
pillar there is a groove made by planing out a portion of the frame or bed of the
machine, in which groove there is a wedge free to slide therein. This wedge is of
such a size at the thicker end thereof that when it is advanced sufficiently it will
entirely fill the space under the pillar, even when it is raised as high as the
aforesaid collar will permit. The said wedge will then prevent any movement of
the fulcrum of the lever, and the needle stock or carrier will receive the full
amount of motion, and a loop of the greatest length will therefore be drawn. The
small end is so thin that when the wedge is quite drawn back it will allow space
for the pillar to move up and down to the full extent required. The motion of the
fulcrum will then be greatest, and that of the needle stock or carrier will be reduced
to the minimum and the shortest loop will be drawn. Upon the awl-cam there is
formed a cam-groove in which the cam-roll on the end of a bell-crank-lover works.
The pivot of the bell-crank-lever is carried on the aforesaid fixed post, and the
lower arm of the bell-crank-lever carries a pawl. The extremity of the aforesaid
wedge is furnished with a rack with which the said pawl; pressed by a spring,
engages. This pawl is subject to be lifted out of the teeth of this rack at certain
times by the action of a lever and cam. This lever oscillates on a fulcrum carried
on a bracket fixed to the frame of the machine; one end is furnished with a roller
and pin running on the cam formed on the surface of the awl-cam. The other end
is prolonged so as to take under a projection formed on the pawl.
The movement of the wedge is thus effected, that is to say, the lower jaw of the
machine, also known as the " table," upon which the work rests, is carried on a
lever with a fulcrum and an arm. The end of this arm is furnished with a pin and
roller which enters into the fork of the locking slide, and as the table is moved up
and down the locking slide is caused to move backward and forward. The end of
this locking slide is prolonged and bent round so as to cross the path of the
aforesaid wedge and form a stop to arrest its advancing movement. The table and
the presser together hold the work, as between the jaws of a pair of pincers, so
that the position of the said table in relation to the presser, and consequently the
position of the said stop, are always regulated by the thickness of the material or
work. The said wedge, under the influence of a spring attached thereto, finds its
way at every successive stitch to the said stop, so that the amount of movement
allowed to the pillar, and consequently to the needle stock, is made to depend on
the thickness of the work.
Although the above description is specially, designed to explain my said
Invention as applied to the sewing machine known as the new Goodyear stitcher,
it is obvious that it may also be applied to any sewing machine in which a curved
needle is employed, with only such modifications, as will be necessary and apparent
according to the nature of the machine..

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by tho said William Henry Dorman in the Great Seal Patent Office on the
12th May 1881.
WILLIAM HENRY DORMAN, of Stafford, in the County of Stafford, Engineer.
"IMPROVEMENTS IN SEWING MACHINERY, CHIEFLY. DESIGNED FOR THE MANU-
FACTURE OF BOOTS AND SHOES."
My Invention consists in improvements in sewing machines which are chiefly
designed for the manufacture of boots and shoes, and in which a curved needle
works with a single thread to produce the kind of sewing termed the chain stitch,
such machines being utilized more especially for stitching the sole to the welt, or.
whatever part may be used in place of the welt in a boot or shoc.
For the production of good work it is a matter of great importance that the
length of the loop of thread drawn up by the needle at each stitch should bear &
certain proportion to the thickness of the material being sewn.
This result may
be obtained by altering the position of the needle in the needle-stock so as to
cause the needle to draw up a longer or a shorter loop. In practice, however, the
thickness of the material varies continually, not only in the different articles
consecutively subjected to the action of the machine, but also frequently in
different parts of the same article, so that the variation of the quantity of thread
in the loops by continued or repeated readjustments of the position of the needle
by hand is obviously impracticable; I have therefore devised the mechanism
hereinafter described for effecting automatically tho adjustment of the length of
the loop to the thickness of the material by and during the action of the machine.
In the accompanying Drawings I have illustrated the application of my
improvements to a sewing machine of the class commonly known in the trade as
the "New Goodyear Stitcher." In these Drawings I have represented only the
parts of the said machine or apparatus that are necessary to elucidate the action
and application of my improvements, and have omitted the awl and the devices for
actuating the same and other portions of the mechanism which are well known
and understood by all persons familiar with the class of machinery to which my
Invention appertains.

page_text: Beneath the post f the frame A has in it a groove A² in which is fitted a wedge g
that is capable of sliding in the said groove. This wedge is sufficiently large or
deep at its thick end g¹ to entirely fill the space left between the foot of the post f
and the bottom of the groove A³ when the said post is raised as high as the
collar will permit. The thin end g³ of the said wedge is so small that when
such end is under the post f the maximum downward movement of the post and the
pivot c¹ is permitted. The aforesaid friction cushion e is employed in combination
with the automatically adjustable pivot or fulcrum c¹ to render certain the effect
of the adjustment of the latter.
"
The wedge g is arranged in combination with the following devices for actuating
or adjusting the same, that is to to say:-h represents the lower jaw of the
machine usually termed the "table." Upon this table the edge of the boot or shoe
sole rests and is held down thereon and firmly gripped or clamped by and between
The said table /
this jaw and the top jaw i usually termed the "channel gauge.'
is carried on a lever h¹ which is pivoted at 2, and whose arm h³ is fitted with a
slide-block h✶ which works in the fork j' formed on the end of the locking slide j.
Or I may use other convenient means for the connection of the said lever with the
locking slide.
It will be obvious that the table being connected to the locking
slide cannot be moved on its pivot h* without at the same time moving the said
slide. This locking slide has a spring connected to it by a pink, or otherwise
the said spring being also connected to a pin at k in the cap l which is fixed on the
frame A. The spring k exerts upon the locking slide ja constant pressure, which
tends to force and keep the table h up against the channel gauge i. The end j* of
the locking slide jis so bent or formed as to extend across the groove in which
tho wedge g moves and form a stop to limit the forward movement of the said
wedge. This forward movement is imparted to the wedge by a spring m
attached to the wedge g at m¹, and to the frame A by the bracket m² to which the
said spring is connected at m³ This spring m exercises a constant pressure upon
the said wedge g to draw it forward or under the post f
As the table h and the channel gauge i hold the work between them, and as the
said channel-gauge is practically fixed as regards the vertical direction (although
during the time the "feed movement" takes place it has a slight up and down
motion) it will be readily understood that any variation in the thickness of the
leather or other material must occasion a movement of the table h. This movement is
communicated to the locking slide j andstop; *, consequently the position the wedge
is free to assume under the post fis dependent upon the thickness of the leather.
I have described the action of the spring which imparts the forward movement
to the said wedge, and I will now describe the devices which prefer to use and
which I have devised for drawing back the said wedge. Upon the awl-cam there
is formed a cam groove n in which works the cam roller n¹ on the end of the bell
crank lever n pivoted at n. The arm ³ of this bell crank lover carries a pawl o.
The wedge has a prolongation furnished with ratchet teeth 9" with which the
said pawl o engages. This pawl is lifted out of or disengaged from the teeth g* at
a certain period in the working of the machine by the action of a lever p and
cam p'. This lever p is pivoted at p³, and is furnished at one end with an anti-
friction roller p³, its other end being extended to form a tail p, which extends
When in the working
under a projection or shoulder o' at the side of the pawl o.
of the machine the cam projection p³ depresses the roller p³, the tail p' of the lever p
acting on the shoulder o, raises the pawl o out of engagement with the teeth g*,
the said lever and pawl remaining in this position until the cam surfaco p¹ has
passed out of contact with the roller ³.
So long as the fulcrum c¹ of the needle-segment c remains stationary, the needle
stock a will receive the whole of the motion that the cam d can impart to it through
the needle segment, but if the said fulcrum c is quite free to move endwise in its
bearings, and at the same time a sufficient resistance is offered by the cushion e, or
otherwise to the movement of the opposite end of the needle segment, it is obvious

page_text: that the whole effect of the cam on the needle segment will be dissipated in moving
the fulcrum c¹ up and down, and the needle stock a will remain stationary.
If, however, the movement of the fulcrum c¹ is controlled or restrained within
sufficiently narrow limits, the action of the said cam will be expended first in moving
or adjusting the fulcrum c' and then in actuating the needle stock a, which will
thus have its motion diminished in proportion to the extent of movement of the
fulcrum c¹, and as the extent of movement of the fulcrum can be regulated, the
length of the loop drawn up may be controlled, for the reason that this length
depends on the distance the barb of the needle b rises above the table h.
In operating with the said machine, when a piece of leather or other material of any
thickness within the capacity of the machine is placed between the table hand, the
channel gauge i, the stop j* assumes a position corresponding with the thickness of
such material. The machine being then set in motion, the awl having passed upward
and pierced the work and the feed having taken place, the locking slide j and stop j*
are locked fast in the position they were caused to assume by the table, the needle
cam & then lifts the fulcrum post f until the collar touches the bearing f¹, and
then rotates the needle stock until the needle has reached its lowest position. In
the meantime the cam n acts upon the bell-crank lever n², and by means of the
pawl o which engages with the teeth g* draws back the wedge g, retains it in position
until the cam in its revolution acts upon the lever p, and lifting the pawl o out of
the said teeth allows the spring m to draw the wedge rapidly forward to the
stop j*. Consequently by the time the cams have revolved to such an extent that
it is time for the needle to return and draw up the loop, the wedge is already in
a position to determine the extent of movement of the fulcrum c¹, which movement,
by the action of the devices herein described, will be proportionate to the thickness
of the material being sewn in the machine.
It will be understood from the foregoing description that my improved mechanism
enables the machine to regulate for itself or automatically the length of the loops
throughout the sewing or stitching of the leather or other material placed between
the jaws.
It will be obvious that my Invention may be applied to a machine in which a
curved needle is carried at one end of a vibrating arm without the intervention of
a needle stock or similar device geared with and operated by the needle segment,
as in the machine shewn in the Drawings. And the said Invention may be modified
with reference to the means for moving or adjusting the needle segment fulcrum;
for instance, the latter may be supported in one arm of a lever whose other arm is
arranged in combination with a wedge which moves vertically or otherwise, for the
purpose of limiting the movement of the said lever and the fulcrum of the needle
segment.
Having thus fully described the said Invention and shewn how the same may be
conveniently and advantageously carried into practice, I wish it understood that I
do not claim the movable or adjustable fulcrum of the needle lever or segment for
automatically controlling the length of the loops in any other machines than those
which have a curved needle, as I am aware that a similar arrangement has been
already employed in straight-needle machines. But by my Invention I have
adapted to curved needle machines this method of obtaining an automatic variation
in the length of the loops according to the thickness of the material, and I claim
in a chain stitch sewing machine,-
First. The employment of a curved needle actuated by a segment, lever, or arm,
which has an adjustable or movable fulcrum, the extent of whose movement is
regulated or determined (through the action of the devices above described, or other
suitable devices) by and according to the thickness of the material being sewn for
the purpose specified.
Second. The combination of parts comprising the movable needle lever or segment
and the post carrying the fulcrum of the said lever or segment, whether the same is
geared with the needle-stock or holder as shewn, or has the needle fixed in it, or is
otherwise arranged for operating the said needle.

page_text: Third. The combination with the said sliding or moving post or other adjustable
support for the needle lever fulcrum of a wedge, for the purpose of varying the
travel or movement of the said fulcrum, to effect the regulation or variation of the
length of the loops, in proportion or according to the thickness of the material being
Bewn, substantially as set forth.
Fourth. The combination with the movable jaw or table, and with the aforesaid
wedge or equivalent dovice, substantially as set forth, of a stop which governs or
limits the movement of the said wedge or device, and thereby controls the adjust-
ment or movement of the needle lever fulcrum in proportion to the thickness of
the material being sewn.
Fifth. The curved needlo, carried by the needle-stock, operated by the needle
lever or segment, which has an adjustablo fulcrum supported in a movable post;
the wedge for limiting the movement of the said post and fulcrum, and the stop for
controlling the position of the said wedge connected with the lower jaw or table,
and adjusted or actuated by the same according to the variations in the thickness
of the material placed between the two jaws; the springs and other parts, arranged
and combined substantially as shewn in the acccompanying Drawings, and operating
as and for the purpose specified.
In witness whereof, I, the said William Henry Dorman, have hereunto set
my hand and seal, this Eleventh day of May, in the year of our Lord One
thousand eight hundred and eighty one.