IMPROVEMENTS IN MACHINERY FOR SEWING BOOTS AND SHOES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the
Office of the Commissioners of Patents, with his Petition, on the
19th March 1870.-A communication from abroad by Charles
Goodyear, junior, of the City and State of New York, United States
of America.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
Southampton Buildings, London, Consulting Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN MACHINERY FOR
SEWING BOOTS AND SHOES," a communication, to be as follows:-
This Invention relates partly to improvements upon the sewing
machine for which Letters Patent were granted to me bearing date
July 29, A.D. 1868, No. 2378, which machine was designed more
especially for sewing welts to insoles and for sewing what are called
turned shoes, but the said Invention relates more particularly to the
machine for sewing the outsole to the welt, for which I have obtained
Letters Patent bearing date June 14, 1869, No. 1814. This last.
mentioned machine is provided with two jaws to clamp the sole and the
welt firmly together while being sewed, the lower jaw which serves as a

page_text: support to the work being stationary, the upper jaw being movable so
as to adjust itself to different thicknesses of leather or in sewing from a
thin shank to a double sole.. In the operation of sewing while the awl
and needle are passing through the work and while the loop is being
drawn tight it is necessary that the work should be clamped firmly
together, but while the feed dog is performing its functions of moving
the shoe along the length of a stitch it is necessary that the pressure of
the upper jaw upon the work should be removed so that the shoe shall
be perfectly free to move.
One feature of this present Invention consists in improvements by
which the above operations are more perfectly performed automatically,
the upper jaw being alternately locked in its position of clamping the
work and released while the feed dog is moving the shoe, these functions
being performed automatically and intermittently at every stitch, though
the same mechanism may be used in connection with this improvement
as in the machines before patented. In the mechanism above referred
to the upper jaw has its bearing or support upon a vertical sliding bar
to which is attached a spiral spring, by the action of which the jaw is
made to press upon the sole of the boot or shoe. In the sliding bar is a
slot or opening through which a screw passes into the column or stand
which supports the sewing mechanism. The object of this screw is to
lock or fasten the vertical sliding bar in any desired position, so that the
position of the axis or support of the upper jaw may be fixed for the
time in a stationary position; by this arrangement when the jaw is set
or fastened to sew a piece of uniform thickness it has an intermittent
motion up and down upon the work just sufficient to allow the shoe to
feed, but this adjustment does not admit of sewing on varying thicknesses
of stock. To obviate this difficulty the use of the set screw referred to
has sometimes been dispensed with, and the spiral spring referred to has
been relied upon to hold the jaw down upon the work with sufficient
pressure to resist the thrust of the awl and needle, but the operation of
this plan is uncertain and unsatisfactory. In order to overcome theso
difficulties I construct the machine with a mechanism for locking or
fastening the vertical sliding bar in a fixed position during the greater
part of the revolution of the cam discs, thus holding the axis upon which
the upper jaw is mounted in a stationary position, so that the roller end
of the jaw which is acted upon by one of the cams has an opportunity to
act more efficiently. The action of the locking arrangements is such that

page_text: the sliding bar is held fast until the upper jaw has released its hold
of the stock, and immediately after the shoe has been moved the length
of a stitch the mechanism for locking and releasing the sliding bar lets
go its hold, so that the jaw may adjust itself to the increased or diminished
thickness of the leather, and is instantly fastened again before the awi
or needle has begun to penetrate the leather, and, as before stated, this
action is automatic and intermittent at every stitch..
Another feature of this Invention consists in improved methods of
regulating the length of the loop automatically according to the varying
thickness of the leather which is being sewed. It is obvious that in
sewing thick stock more thread will be required to form a stitch than
in sewing thin stock, and some provision must be made to regulate the
supply of thread according to the thickness of the stock. This part
of the Invention is carried out by means of a take-up roller, around
which the thread passes on its way from the bobbin to the needle,
the roller being by preference in such a position that a line drawn
from it, when at rest, to the bobbin will form nearly a right angle
with a line drawn from the roller to the needle. The roller is mounted
on a frame which is vibrated against the resistance of a spring by
means of the varying thickness of the work, so that the roller is
made to take different positions and regulate the length of thread or
loop according to the varying thickness of the work. The tension upon
the thread in these machines is best applied or regulated by applying
friction to the bobbin or spool upon which the thread is wound. From
the bobbin the thread passes under or over a small grooved roll upon the
end of a spring (or a suitable piece of mechanism acted upon by a spring),
and from this roll the thread passes through the warming tuble and
looper to the barb of the needle. (I would here state that the best
position for the bobbin with reference to the aforesaid spring roll is such
as to bring the line of the thread from the bobbin to said roll at right
angles to the line of thread from said spring roll to the eye of the
looper.) Now in the operation of sewing the needle in drawing up the
loop through the leather will cause the said spring roll to yield or give
way until the resistance of the spring becomes greater than the resistance
of the friction on the bobbin, in which event the thread will begin to
draw from the bobbin, and when the needle slacks up the loop in its
downward motion the reaction of the spring will draw back a certain
portion of the loop with it. It is obvious that by regulating the throw

page_text: of this spring between certain fixed points (as between two check nuts
or screw heads for example), and by a proper adjustment of the tension
on the bobbin the length of the loop may be adjusted or regulated to suit
different thicknesses of stock or different lengths of stitches.
The automatic adjustment of the throw or action of the "take-up" or
spring roll is regulated as follows:-The elevation or position of the
perpendicular sliding bar is governed by the thickness of the leather
upon which the upper jaw rests. Connected with this sliding bar is a
lever which passes through the column or stand near the top, having its
axis of support near the centre of said lever. To the opposite end of this
lever is connected by a hinge joint or other suitable connection another
bar or rod which extends down at the back of the machine to the point
where the thread passes from the spring roll into the opening of the
warming tube; the lower end of this rod is bent at right angles to its
length, and upon the projection formed by this bend is a sliding piece
which is adjusted in any required position by a screw which passes
through it. The object of this sliding piece which projects downwards
about half an inch is to form a stop against which one of the arms of the
piece called the "take-up" strikes. This piece is a three-armed or
T-shaped piece of metal pivoted at the intersection of its arms. Upon
the upper and outward arm of this "take-up" is mounted the grooved
roll called the spring roll, and upon the lower outward arm is a small
friction roll against which the flat spring which operates the spring roll
bears or operates; the other arm extends inwardly, and in the operation
of sewing brings up or strikes against the stop above described. The
action of this combination of bars and levers with the back spring is such
that when the upper jaw rests upon thin stock the stop upon the lower
end of the bar at the back of the machine is raised to a higher point
then when sewing thick stock, and consequently the back spring has
more range of action and draws back more of the loop, and when sewing
thick stock the stop descends in like proportions, and the back spring
having less motion draws back less of the loop. This action it will be
seen is such that the proper supply of thread is provided or drawn back
according to the thickness of the stock at every stitch. In the machine
for sewing welts, in sewing around a short curve as around the heel or
toe, it is found that a less or shorter length of loop is required in
consequence of the inner circle where the double loop lies being the
shortest, though the thickness of the stock may be the same. To
provide for this variation, and change the length of the loop accordingly,

page_text: I place a wedge-like sliding piece of metal or other suitable material
behind the spring, between it and the back stop or screw; this slide may
be mounted in any convenient manner and is operated manually by the
operator who pushes it out or in according to circumstances, thus
changing the action of the spring; for example, while sewing along the
side of the shoe the thick part of the slide or wedge will be between the
back stop and the spring, but when the toe is reached the operator pulls
the slide out so that the thin part of the slide will come between the
back stop and the spring, thus increasing the throw or action of the
spring and causing it to draw back and shorten the loop. The moment.
the operator has sewed around the toe to the opposite side he pushes.
back the slide, thus again shortening the action of the spring and
lengthening the loop. In the machine for sewing the sole to the welt it
is necessary to be able to open the jaws so as to insert the work readily
or to remove it at pleasure, but as the sliding bar upon which the upper
jaw is pivoted is liable to be locked fast by the locking arrangement
above referred to a special device is requisite to unlock or release the
pressure upon the vertical sliding bar, this is accomplished by this
Invention by means of an eccentric having a projecting lever, which is
connected by a small rod with a foot treadlo; this eccentric is pivoted
immediately under the above-mentioned locking mechanism, so that by
placing the foot on the treadle the piece which presses against the vertical
slide is lifted from it, and by continuing to depress the treadle the upper
jaw is raised from the work.
Another feature of my Invention relates to an improved method of
clamping and holding the needle and awl in their respective sockets by
inserting said sockets or socket pieces into the needle or awl stocks so
that they can be readily removed and interchanged for needles or awls of
different sizes.
Another feature relates to the manner of mounting and constructing
the feed dog by suspending the same from a pivot situated in a vertical
plane above the working edge of the dog and operating it by a
simple rod.
Another relates to the combination of the well-known device for
holding the boot or shoe in a pegging machine with sewing mechanism
in sewing on the welt.
Another feature relates to constructing and mounting the lower jaw in
the machine for sewing the outsole to the welt by means of a simple

page_text: bracket secured to the front of the machine whereby the construction of
the jaw is materially simplified.
Another feature relates to constructing and mounting the stationary
or channel gauge, and also the yielding or back gauge, in the machine
for sewing welts, the said channel gauge being made in the simplest
possible form so as to save labor.
Another feature relates to a device for preventing the dropping of loops
which sometimes occurs in sewing on both the machines referred to, tho
said device consisting of a hook which catches in the loop and prevents
it from slipping off from the barb of the needle when the same begins to
descend.