IMPROVEMENTS IN SEWING MACHINES, CHIEFLY DESIGNED FOR THE MANUFACTURE OF BOOTS AND SHOES
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,'
& Co., Patent Agents, Southampton Buildings, London, for an Invention
of "IMPROVEMENTS IN SEWING MACHINES, CHIEFLY DESIGNED FOR THE
MANUFACTURE OF BOOTS AND SHOES." A communication from abroad by
John Brayton Anthony, of Providence, Rhode Island, United States of
America.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 7th September 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN SEWING MACHINES,.
CHIEFLY DESIGNED FOR THE MANUFACTURE OF BOOTS AND SHOES."
A com-
munication from abroad by John Brayton Anthony, of Providence, Rhode Island,,
United States of America.
This Invention relates to sewing machines which are particularly adapted for
sewing soles upon boots and shoes and stitching leather, and the like, and which
form a "lock-stitch," and have a shuttle located upon the side of the work from
which the needle approaches.
My improvements relate to the completion of the stitch, to the mechanism
employed for controlling the main or spool-thread during the formation of a stitch,
and to means for locating the position of the lock of the threads in the goods.
In lock-stitch sewing machines as usually heretofore constructed the main thread
has been drawn in to finish the stitch by the rising needle, and in machines which
are particularly adapted to sew leather and the like, and in which the shuttle is
located upon that side of the work from which the needle approaches, the thread
has been drawn in to finish a stitch during and by the operation of forming the
initial portion or loop of the subsequent stitch. The result of this method of
finishing the stitch has been to bring an undue strain upon the thread as it passes
through the needle-eye, and is sharply bent around the same, causing the thread to
be considerably chafed, and oft times to be broken.

page_text: The main object of the said Invention is to remedy this defect, and for this
purpose I finish the stitch independently of the needle, and before a subsequent
stitch is commenced, as will appear from the following description :-
Referring to the Drawing,
Figure 1 is a front elevation partly in section of a portion of a machine
embodying my improvements.
Figure 2 is a vertical section on the line x, x, Figure 1.
Figure 3 is a vertical section on the line y, y, Figure 2.
Figures 4, 5, and 6 are front elevations of portions of the said machine, and shew
a stitch in various stages of formation; and
Figures 7, 8, and 9 represent certain parts of the machine in detail, and drawn
to an enlarged scale.
In the Drawing only such portions of the machine are shewn as are necessary to
enable my improvements to be readily understood.
A is the "horn" or bed adapted to support the work, and commonly used in
bottoming boots and shoes; B is the needle secured in the needle-bar B¹, to which
the vertical reciprocating motions are given by the usual mechanism employed for
this purpose in such well known machines; C is the hook-shuttle mounted in a
holder C, and arranged to revolve in a horizontal plane at the proper time, and
pass the threads which it carries through the loop formed in the under or spool
thread; D is the spool which supplies the main or under thread. This spool is
mounted on a standard secured to the base portion or member A' of the horn. The
thread passes from the said spool D to a drum wheel E, which is loosely mounted
and revolves freely upon a spindle E¹, Figures 1, 2, 3, and 7, except when it is
locked so as to prevent its rotation, as hereinafter described.
Between the spool D and the drum or wheel E is a roller F which is mounted
on an arm F¹, and is caused to press the thread against the said wheel by the
action of a spring f, shewn in Figures 1 and 3; this roller constitutes a spring-
clamp to press the thread against the surface of the drum, in order to create a
considerable extent of frictional contact between the thread and the said drum.
The spring-clamp also serves to give a slight tension to the thread to prevent its
slipping, and dispenses with the necessity of wrapping the thread one or more
times around the drum for that purpose.
From the roller F the thread passes nearly around the drum or wheel E, then
around a roller G which is located considerably above the horizontal diameter-of-
the drum E, and is mounted on a vibrating arın G¹, so that when the said arm is
vibrated, as hereinafter described, the said thread roller-guide G will move in a
path concentric with the periphery of the drum E. From the said roller G the
thread passes through a slotted guide-eye g overlying the roller G, and concentric
therewith, as shewn in Figures 8 and 9, onward around a pulley a, then upward
and out through the end of the horn A, as shewn in Figure 1.
To the hub of the arm G¹ is attached a segmental rack g¹, Figures 1, 2, and 3,
which gears with a similar rack h upon a lever H pivoted to the base-member A¹
of the horn, as shewn in Figure 1. The arm G₁ with its roller G is partially
rotated in opposite directions by the upward and downward movements of the
toothed end of the said lever H. These movements are imparted to the said lever
through a vertically sliding rod J (pivotted thereto, as shewn in Figure 1) by a
lever K, which is pivoted to a sleeve k mounted on the said rod J between a
shoulder or nut j and a-nut j. The lever K is actuated by a cam or equivalent
mechanism not shewn in the Drawing, or in any other suitable manner.
Supposing the machine to be in operation, and that a stitch is about to be
commenced, the needle will be at its lowest point, as shewn in Figure 4, and the
roller G will be in its rearward position, that is to say, near the roller F, as shewn
by dotted lines in Figure 1. By mechanism well known in this class of machines
the under thread is now partially wound around the needle, so that when the latter
rises its hooked end will engage the thread and carry it upward to form the loop
through which the shuttle is to pass. When the needle commences to rise, and

page_text: during the greater portion of its upward movement, the arm G' with its roller G is
moved towards the horn A by the downward motion of the lever H, and delivers
to the needle the exact amount of thread which is entering into the loop. No
thread passes from the spool at this time, as sufficient thread to form the greater
portion of the loop is given off by the swinging arm G¹ and its roller G. To guard
against any rotation of the spool by the pull of the needle when it is rising to
form this portion of the loop, the wheel E is firmly clamped to prevent its rotation
by a tooth on an arm L, which arm is pivoted to the base A¹. This tooth
occupies a groove e in one side of the wheel E (see Figures 3 and 7), and is brought
into engagement with the outer wall of the said groove to clamp the wheel by a
spring L, Figures 2 and 3, which constantly tends to raise the outer end of the
said arm L. The friction of the thread upon the clamped wheel added to the
pressure of the roller F upon the thread prevents the rising needle from drawing
thread from the spool.
At some time during the rise of the needle however sufficient thread to form a
stitch must be drawn from the said spool. In the arrangement of machine shewn,
this is done as the needle approaches its highest point. For this purpose the drum
or wheel E is unclamped by the action upon the free end of the arm L of a pin or
boss on the lever H, Figures 2 and 3. As the lever H descends the boss h³
comes in contact with the arm L, depresses its free end, and moves the tooth out
of engagement with the wall of the groove e, leaving the drum or wheel E free to
turn, and the needle during its continued rise draws from the spool without
embarrassment an amount of thread equivalent to that which is to enter into the
stitch, this amount of thread entering into and completing the loop. At or about
the time the needle reaches its highest point a finger m on a vibrating arm M,
which is actuated by a cam or equivalent mechanism not shewn in the Drawing, is
made to separate the legs of the loop in the ordinary manner, as shewn in Figure 1.
The hooked end of the needle now descends into a perforation in the finger m to
clear itself of the thread, as shewn in Figure 5, and the shuttle in revolving enters
the loop. The tinger m is next withdrawn by a downward and rearward movement,
and the shuttle and its thread pass through the loop, leaving the same standing up
from the goods or material being sewn.
The stitch is now ready to be finished or drawn in. This is accomplished
independently of the action of the needle in forming the next stitch by the arm G',
which as the shuttle clears the loop is moved rearward by the rising lever H of the
second order, and draws the loop down towards the goods, as shewn in Figure 6.
At the same time the drum or wheel E is locked fast to prevent its rotation,
because the rising of the lever H allows the spring L' to cause the tooth on the
arm L to engage the drum or wheel E and clamp it, so that no thread can pass
from the spool during the finishing of the stitch. When the arm G¹ and its roller
Greach their rearward position, the stitch will be completed, that is to say, the
under and shuttle threads will both be drawn down into the goods by the action
of the arm G' on the under or spool thread, making a lock-stitch.
Preferably the lock of the stitch is located at or about a point midway between
the upper and under surfaces of the work, but as the work differs in thickness and
character it is necessary that means be employed whereby the position of the lock
of the threads can be determined at pleasure. From the foregoing description it
will be understood that the position of the lock of the threads is determined by the
novement of the arın G¹, and that this arm derives its motions from the lever K
through the rod J and lever H. According therefore to the length of time which
the sleeve / pivoted to the lever K engages the nut j' on the rod J while the said
lever is in motion, the amount of the rearward movement of the arm G¹ will be
more or less in extent. The lower the nut 1 is adjusted on the rod the greater
will be the rearward movement of the arm G¹, and the deeper will the lock of the
threads be drawn into the goods; moreover, the higher the adjustment of the nut
the less will the arm G¹ move rearward, and the nearer to the upper surface of
the work will the lock of the threads be located.

page_text: During the drawing in or finishing of the stitch the needle will descend, and
when the arm G' reaches its rearward position the work will be fed forward and
the operations above described will be repeated to form subsequent stitches.
The slotted guide eye g is, as before stated, connected with the thread-guide-
roller G. This construction is important, for the reason that it enables the thread
to be guided without being chafed 'in all the positions which the roller G is
obliged to assume, as the result of the vibration of the arm G' when acting in
combination with the then stationary drum or wheel E to complete the stitch.
To regulate the friction upon the drum E at the times when it is intended to
revolve in allowing thread to be given off for sewing, a simple friction device, such
as is represented in section at Figure 2, may be applied to the hub of the said
drum.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it
understood that I claim,-
First. The combination substantially as above set forth of the drum or wheel E,
around which the main thread passes and which in the formation of a stitch by the
machine, is first free to revolve to allow the thread to be given off' and afterwards
locked to prevent its rotation, a vibrating arm G' mounted on the axle of the said
drum, or equivalent device carrying a roller or guide for the thread, and a lever, H
or equivalent means for causing the said arm to be vibrated rearward over the
periphery of the said drum or wheel, while the latter is locked to prevent its
rotation, whereby the under or main thread is pulled backward to fully complete
the stitch in the work.
Second. The combination substantially as above set forth of the drum around
which the main thread passes, a spring-locking L, 1, and the lever H, the upward
and downward movements of which control the said locking device so that at
determined times the drum will be free to revolve to give off the thread and
afterwards be locked while the thread is being drawn backward to complete the
stitch.
Third. The combination- substantially as above set forth of the drum E, the
pressure-roller-clamp F, and the vibrating arm G carrying a guide-roller for the
thread, whereby the thread when the drum E is locked to prevent its rotation will
by frictional contact with the surface of the drum be prevented from slipping
thereon.
Fourth. The combination with the vibrating arm G' and the thread guide-roller-G
of the slotted guide-eye concentric with the said roller, substantially as above set
forth and for the purpose specified.
Fifth. The combination substantially as above set forth of the lever H, the
vibrating arm G¹ carrying a thread-guide-roller, and suitable adjusting devices as
described, for regulating the extent of movement of the lever, H and consequently
the extent of vibration of the arm G', whereby the position of the lock of the main
and shuttle threads in the goods may be determined.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Seventh day of September. in the year of our Lord One
W ROBT. LAKE. (L.S.)