IMPROVEMENTS IN SEWING MACHINES
Year: 1866

page_text: LETTERS PATENT to Thomas Henderson, of Glasgow, in the County of
Lanark, North Britain, for the Invention of "IMPROVEMENTS IN SEWING
MACHINES."
Sealed the 26th April 1867, and dated the 1st November 1866..
PROVISIONAL SPECIFICATION left by the said Thomas Henderson at
the Office of the Commissioners of Patents, with his Petition, on 'the
1st November 1866.
I, THOMAS HENDERSON, of Glasgow, in the County of Lanark, North
Britain, do hereby declare the nature of the said Invention of "IMPROVEMENTS
IN SEWING MACHINES," to be as follows, that is to say :-
The improvements embodied under this Invention consist essentially in
constructing the feed arrangement in that class of machines known as elliptical
sewing machines, so that the feeding teeth are situated both in front and back
of the needle, by which: arrangement a more perfect feed is obtained than
hitherto.
Another improvement consists in driving: the needle arm by eccentric
motion, the eccentric being placed on a shaft driven by a belt underneath the
table.
A. third improvement consists in governing the motion of what is known as
the elliptic hook by a piston or plunger working in a cylinder, instead of a
connecting rod, whereby greater steadiness of motion is obtained.

page_text: Another part of this Invention consists in the bobbin holder being fixed to
the front instead of at the side, by which arrangement the bobbin is more
easily got at for removal or replacement.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Henderson in the Great Seal Patent Office on
the 30th April 1867.
"
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HENDERSON, of Glasgow, in the County of Lanark, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of November, in the year of our Lord One
thousand eight hundred and sixty-six, in the thirtieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Henderson, Her special license that I, the said Thomas Henderson,
my executors, 'administrators, and assigns, or such others as I, the said
Thomas Henderson, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "Ix-
PROVEMENTS IN SEWING MACHINES," upon the condition (amongst others) that I,
the said Thomas Henderson, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said In-
vention, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Henderson, do hereby declare
is to
the nature of my said Invention, and in what manner the same.
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings and
to the letters and figures marked thereon, that is to say:-
My said Invention consists essentially in constructing the feed arrangement
of that class of machines known as "elliptical" sewing machines, so that the
feeding teeth are situated both in front and back of the needle, by which
arrangement a more perfect feed is obtained than hitherto.

page_text: Another improvement consists in driving the needle arm by eccentric
motion, the eccentric being placed on a shaft driven by a belt underneath the
table; whilst a third improvement consists in governing the motion of what is
known as the "elliptic hook" by a piston or plunger working in a cylinder
instead of a connecting rod, whereby greater steadiness of motion is
obtained.
Another part of this Invention consists in the bobbin holder being fixed
to the front instead of at the side, by which arrangement the bobbin is more
easily got at for removal or replacement.
And in order that my said Invention may be properly understood I shall now
proceed more particularly to set forth the system, mode, or manner in or
under which the same is or may be used or practically carried into effect,
reference being had for the sake of more complete elucidation to the several
Figures upon the explanatory Sheet of Drawings, which I have hereunto
appended, that is to say,—
Figure 1 is a side elevation, Figure 2 a front elevation, and Figure 3 a
plan of the "elliptical sewing machine" constructed in accordance with my
present improvements, which consist in applying the eccentric A for giving
the necessary vibratory motion to the needle lever B through the medium
of the eccentric rod C. On the shaft D carrying the eccentric A the feed
cam E is situated; this cam is made of the form shown at Figure 2, so that
as the thickest part of the cam passes through the upper half of its revolution
it carries back the feed bar F, and at the same time lifts it by means of the
periphery at one part of the cam, being slightly elevated, or being of larger
diameter. As the feed bar is thus lifted the notches a, a, Figures 1, 2, and 4,
catch in the cloth, and as the revolution is continued the thick edge of the
cam descends in its revolution, whilst the thin half ascends, so that the feed
bar F is free to be moved horizontally by an amount corresponding to the in-
clination of the oblique side of the cam. The spiral spring G pulls the feed
bar constantly, and it is thereby maintained in constant contact with the cam.
When the feed bar arrives at the left hand end of its stroke that part of the
cain which is of smallest diameter acts upon the lever, the lever therefore
descends' below the level of the table H, and is therefore out of contact with
the cloth; and the cam on being revolved further round carries the feed bar to
the right hand end of its stroke, and as it approaches to the end of that
stroke the thick part of the cam again coming uppermost lifts the feed bar to
catch the cloth for the next onward movement. The feed notches a, a, being
principally situated behind the needle,. in place of before it, as hitherto, enables
the cloth or work to be drawn through with greater smoothness, and also

page_text: prevents puckering.. The bobbin holder consists of the framework I, to which
the spring I¹ is attached, the pressure produced by. the compression of which.
keeps the bobbin J in place; this can at, any time be removed by merely
withdrawing or unscrewing the. thumb nut K; by which it is held in place.
The bobbin holders and bobbin are shown in detached views. at Figures 4, 5,
6, and 7.
The hook L for forming the stitch is secured to the crank by a screw
pin,.as shown at Figures 1 and 2, and its lower end is jointed to the piston
or guide rod M, which as the machine is at work is reciprocated upwards
and downwards in the cylindrical guide socket N; in this way an exceedingly
steady movement of the hook is obtained, and it is not liable to miss stitches
after the machine has been much worked. When the under bobbin requires
to be refilled the holder is detached, and the bobbin being thus taken out is
placed on the tappet shaft, as shown at Figure 2'; the shaft being rotated the
thread is rapidly wound thereon; by this arrangement the use of a bobbiu
winder, as hitherto adopted with "elliptical" sewing machines, is dispensed
with.
.
By the foregoing arrangements the framework which carries the mechanism
as well as the stationary arm are capable of being cast all in one piece, so
that there cannot be any disarrangement or shifting of any of the parts out of
their working positions.
To avoid misapprehension as to the term "elliptical sewing machines"
I wish here to explain that it is the name applied to those machines in which
the hook L being extended beyond the crank centre moves through each
revolution in the path of an ellipse.
Having now described the nature of my said Invention, and the manner in
which the same is or may be used or practically carried into effect, I would
observe, in conclusion, that what I consider novel and original, and therefore
claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,-.
First, the general arrangement and construction of "elliptical" sewing
machines as berein-before described, or any mere modification thereof.
Second, the application and use of an eccentric for actuating the needle
lever of sewing machines, as herein-before described.
Third, the use and application of the cylindric guide and plunger for im-
parting a steady movement to the elliptically moving hook, as herein-before
described, or any mere modification thereof.
Fourth, the placing of the principal part of the feed notches behind the
needle, so that the carrying forward of the work is more evenly performed, as

page_text: herein-before described, and more particularly shown at Figure 2 of the
annexed Sheet of Drawings.
Fifth, the arrangement and construction of bobbin holders, as herein-before
described and shown in the accompanying Sheet of Drawings.
In witness whereof, I, the said Thomas Henderson, have hereunto set
my hand and seal, this Twenty-ninth day of April, One thousand
eight hundred and sixty-seven.