IMPROVEMENTS IN SEWING MACHINES
Year: 1858

page_text: LETTERS PATENT to Lucius A. Bigelow, of 188, High Holborn, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN SEWING
MACHINES." A communication.
COMPLETE SPECIFICATION filed by the said Lucius A. Bigelow at the.
Office of the Commissioners of Patents, with his Petition, and Declara-,
tion, on the 11th June 1858, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Lucius
A. BIGELOW, of 188, High Holborn, in the County of Middlesex, Gentleman,
send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
SEWING MACHINES," and have petitioned Her Majesty to grant unto me, my
executors, administrators, and assigns, Her Royal Letters Patent for the
same, and have made solemn declaration that the same is a communication
from a foreigner residing abroad.
NOW KNOW YE, that I, the said Lucius A. Bigelow, do hereby declaro
that the following Complete Specification, under my hand and scal, fully
describes and ascertains the nature of my said Invention, and the manner in
which the same is to be performed, reference being had to the accompanying
Drawings, that is to say:-

page_text: The nature of my improvement consists, first, in so constructing a sewing
machine that it shall be applicable to two kinds of sewing, i.c., to sewing with
a single thread and to sewing with a double thread.
Second, in the improved mechanism for taking, spreading, tightening, and
interlacing the loopes, whereby the several operations are effected with greater
accuracy and speed, and less liability of the mechanism getting out of order
aro attained.
Sewing machines as constructed upon the numerous plans devised are, with
no exception, specially applicable to one kind of sewing. Single-threaded
machines, although very useful, and preferable to double-threaded machinos
for family or domestic purposes, do not answer the purpose of sewing heavy
fabrics, such as cloth, leather, and of other goods, where the liability of the scam
being unravelled is more or less objectionable. Experience having taught the
importance of both kinds of sewing, it was my endeavour to construct a
machine which will sew both the chain and lock stitch, or the single and
double-threaded stitch.
The annexed Drawing represents different views of the mechanism of a
sewing machine, which operates both the needle arm and the looper, in such
a manner that by the mere substitution of one looper to the other, the
machine will sew either the chain stitch or a stitch which cannot be un-
ravelled, and which I would call the weaver's stitch.
Figs. 1 and 2 represent the bottom view of a machino constructed after my
plan, showing the looper respectively in its extreme positions, i.c., when the
crank pin a is placed horizontally in diametrically opposite positions; Fig. 8 is
a side elevation, and Fig. 4 is a front elevation.
In this Drawing the goosneck needle arm, feeding device, and all other
parts of the machine above the table, are suppressed, inasmuch as my improve-
ment is applicable to all kinds of sewing machines where the needle has an
up-and-down motion through an aperture in the table.
.
In the machino here shewn, the needle arm A being a bent lever pivoted in
or on to a gooseneck or standard, is driven by a crank pin a inserted in a slot
wrought in the lower extremity of the arm; the crank being connected with
a pulley B, which is geared by a belt embracing both the pulley and a fly
wheel, or by friction against a fly wheel. In the latter case, I prefer to cover
the pulley with an elastic or yielding material, such as an india-rubber cord, in
order to insure constant contact of the parts in gear. The slotted needle arm
having thus a vibratory motion, I construct the mechanism operating the
looper so as to impart the motion thereto in a positive manner, whereby
infallibility of the operation is ensured. The needle arm below the sewing

page_text: table is provided with a bracelet C, to which is secured on the upper sido tho
lever D, vibrating upon a fixed fulcrum at C, and on the under side the rod E,
capable of a compound motion in the direction of its length, and of that
imparted to it by tho lever D being guarded by an eyo F, which is secured to
said lover. This lever terminates at its front extremity into a mortice, into
which either of the loopers shown in Fig. 11 and Fig. 12 is adjustable; the
former is for making a chain stitch, and the latter for a double-threndod
stitch, which may be called either a lock stitch, because the thread is locked,
i.e., not liable to be pulled out, or weaver's stitch, because the upper thread is
woven in by an under thread, so that the loop is permanently secured.
In order that the operation be understood, I will now describe particularly
the construction of each, and the relation which the different parts bear with
those of the operating mechanism; both loopers are perfectly similar; both
have an eye through which the pine passes, and which secures them into tho
mortice, and in which they are free to move when actuated in the manner
herein-after described; both have a projecting arm 9, wherein a spiral
spring his hooked, and which causes the looper to bear closo against a
shoulder which is adjustable by means of a screw i. Finally, both have a
shield projecting from lower side downward, so as to face or to be in a line with
the rod E. They differ from each other in the construction of the hook only;
in Fig. 11 the hook is furnished with a shoulder near its point; this hook
being intended for the chain stitch sewing. The office of the shoulder will
readily be understood. The needle on its downward stroke carries the thread
through the fabric, and brings a loop under the table, which is spread when
the needle begins its upward motion at the moment the hook enters the loop,
carries it onward, and holds it by means of the shoulder spread open in the
path of the needle. On the next stroke the needle will then pass through tho
loop, when the hook will withdraw and release the former loop, in order to
catch a new loop from the needle. In Fig. 12 the hook has no projection or
shoulder, but is eye-pointed, that is, there is an eye near the point. This hook
is intended for the double-threaded stitch. Its operation will be understood
from the description of the following parts:-In the immediate vicinity of the
orifice in the table through which the needle passes is a stationary hook K,
slightly bent downwards, and shaped and located in such a manner as to
present a convex edge toward the path of the hook, whereby the thread in
and upon the hook will be caught and held for a requisite length of time. At
some convenient part of the plate of the machine there is an attachment G,
for supporting and producing tension upon a spool, which contains the under
thread, also a thread guide and thread tightener I. This consists of a forked

page_text: 'rod, around which is wound a wire, the extremity of which is bent into an
eye; the thread is passed through said eye, and the slot of the rod, whereby it
will be tightened at every stitch. To illustrate the operation of the eye-
pointed looper, I have represented in Figs. 5, 6, 7, 8, 9, and 10, the several
'successive positions of the looper in relation to the stationary book and the
'needle, showing also in what manner the thread is convoyed to form the stitch
'above referred to.
Fig. 5 shews the first stage of the operation, the looper being at its greatest
distance from the needle, and the needle at the lowest point of its stroke,
corresponding to the horizontal position of the crank shewn in Fig. 1; Fig. 61
represents the looper and needle in the next position corresponding to a
vertical and down or upward position of the crank (it is unimportant which
"way the pulley turns, each revolution effecting a vibration of the needle bar),
'the looper having penetrated the loop brought downward, now opened by the
retreat of the needle, carries the under thread or the thread shewn in red lines']
through the loop, while the needle has risen, so as to draw the loop close to
the looper. The crank now turns onward to complete. three-fourth of its
revolution, shewn in Fig. 2. By this motion of the crank the slotted needle
arm is brought to the position shewn in Fig. 7, whereby the rod E is caused
to push forward and to rotate the looper around its fulcrum, so as to pass 2
beyond the stationary hook K. The thread in the eye of the looper being.
now brought in the path of the stationary book, will be caught and retained
by said hook on a retreating. motion of the looper. This is effected by the
downward motion of the crank, which actuates the rod to withdraw the
spring h, pulling back the looper to the position shown in Fig. 1, where it is 2
retained until pushed again by the rod. The under thread forms now a loop,
which is spread and held open in the path of the needle, as shown in Fig. 8,
but as soon as the needle penetrates this under thread loop, the latter is
released and slips off the hook on the needle, and is drawn close thereto by the
retreat of the looper (see Figs. 9 and 10).
Having now fully described my improvement in sewing machines, what I
claim as new and desire to secure by Letters Patent is,―
First, constructing and arranging the mechanism of a sewing machine
substantially as described, so as to render it adaptable to two kinds of sewing,
namely, to a single and double-threaded sewing, as set forth.
Second, constructing the loopers a, y, in manner specified, whereby either
'may readily be adjusted to the lever, in order to operate in the manner and
for the respective purposes 'set forth.
Third, the mechanism for forming a double stitch in the manner described
8
8

page_text: consisting of a combination of a stationary hook and an eye-pointed looper,
when arranged in relation to the needle, to operate as specified.
Fourth, I claim the shield projecting from the looper in combination with
the rod E and retaining spring h, operating in such a manner as to impart to
the looper a positive motion, as described.
In witness whereof, I, the said Lucius A. Bigelow, have hereunto set my
hand and seal, this Eleventh day of June, in the year of our Lord
One thousand eight hundred and fifty-eight.
L. A. BIGELOW. (L.S.)