IMPROVE- MENTS IN SEWING MACHINES
Year: 1872

page_text: LETTERS PATENT to Norris Parmby Stockwell, of No. 64, Regent
Street, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN SEWING MACHINES."-A communication from abroad by The
Howe Machine Company, of Bridgeport, State of Connecticut,
United States of America.
Sealed the 23rd July 1872, and dated the 7th February 1872.
PROVISIONAL SPECIFICATION left by the said Norris Parmby Stockwell
at the Office of the Commissioners of Patents, with his Petition,
on the 7th February 1872.
1
I, NORRIS PARMBY STOCKWELL, of No. 64, Regent Street, in the
County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SEWING MACHINES," to be as follows :-
This Invention has for its object improvements in sewing machines,
and consists, firstly, of an improved construction, combination, and
arrangement of parts of apparatus for regulating the length of stitch
when a serrated feed plate acting upon the under side of the fabric or

page_text: usual carries the needle slide and presser stem, and which is itself carried.
at the end of the arm of the machine.
The Invention further consists of an improved apparatus to vibrate
the presser at any desired' time of the needle's rest, or dwell, or of its
motion. This is effected by motion imparted by a cam on the cam
shaft beneath the bed plate through the intermediacy of suitably
arranged cranks to the presser bar in its place in the slide box.
The Invention further consists of an improvement in barrel cams of.
sewing machines to diminish the bulk and weight of metal from that
heretofore employed, and is effected by employing a raised cam rim.
instead of the entire cylinder surface being carried over the whole
exterior of the barrel of the cam.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Norris Parmby Stockwell in the Great Seal Patent
Office on the 7th August 1872. .
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, NORRIS
PARMBY STOCKWELL, of No. 64, Regent Street, in the County of Middle-
sex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of February, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Norris Parmby Stockwell, Her special
license that I, the said Norris Parmby Stockwell, my executors, adminis-
trators, and assigns, or such others as I, the said Norris Parmby Stock-
well, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter 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 "IMPROVE-
MENTS IN SEWING MACHINES," a communication to me from abroad by The:
Howe Machine Company, of Bridgeport, State of Connecticut, United.
States of America, upon the condition (amongst others) that I, the said

page_text: Norris Parmby Stockwell, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
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 Norris Parmby Stockwell, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say:-
This Invention has for its object improvements in sewing machines,
and consists, firstly, of an improved construction, combination, and
arrangement of parts of apparatus for regulating the length of stitch
when a serrated feed plate acting upon the under side of the fabric or
work is employed. This is carried into effect by varying the position of
the fulcrum of a lever jointed to a bar which carries the serrated feed
plate. This lever at its upper end is jointed to the bar carrying the
serrated plate, and at its lower end rests against a cam on the driving
shaft. The varying fulcrum of the lever is formed by the end of an arm
against which the lever bears, which arm is carried by a horizontal axis
running lengthwise of the machine from front to rear underneath the
bed plate. By causing the axis to partly turn the end of the arm upon
it can be raised or lowered and thus brought nearer to or further from
the end of the lever which is jointed to the bar carrying the serrated.
feed plate.
The amount of horizontal motion given by the lever to the serrated
feed plate, and consequently the length of stitch, can thus be varied.
The bar carrying the serrated feed plate has a spring attached to it, which
serves to hold it down on to the cam, which acts upon it to give to it a
rising and falling motion, and also serves to draw it backwards.. This
spring also serves to keep the lever before mentioned always bearing
against the side of the cam by which it is actuated.
When the length of stitch is to be varied the axis before mentioned. is
turned partly round by turning a screw, which screws through the back
end of the bed plate. An arm on the back end of the axis bears against
the bottom of the screw, and is kept against it by a spring attached to

page_text: another arm on the axis, by preference the same spring which draws
back the serrated feed plate.
This Invention further consists of an improved construction and..,
arrangement of an apparatus for raising or lifting the presser foot to...
enable the operator working the machine to readily raise the spring:
presser plate, which holds down the fabric while the machine is at work.
A small lever is employed, one end of which is connected to the stem by
which the spring presser plate is carried, and the other, which is towards
the person working the machine, is formed into a thumb piece, by
depressing which the presser plate can be held up. When the stem of
the presser plate is made circular to allow of the presser plate when :
raised being turned aside to be out of the way, a pin on the end of the
lever before mentioned enters a groove cut around the stem so that the
turning of the stem is not interfered with. The lever turns on a pin
screwed into the lower part of the back of the box or frame, which as
usual carries the needle slide and presser stem, and which is itself carried
at the end of the arm of the machine.
7' 3
The Invention further consists of an improvement in barrel, cams of
sewing machines to diminish the bulk and weight of metal from that
heretofore employed, and is effected by employing a raised cam rim
carried by arms from a central boss instead of the entire cylinder surface
being carried over the whole exterior of the barrel of the cam.
f
:
In the Drawings hereunto annexed; I have shewn a sewing machine
in which each of the improvements above described is embodied.
Figure 1 is a side view, partly in section, and Figure 2 an end view of
the machine. a is the serrated feed plate carried by a bar b, which can
slide to and fro; c is a lever jointed at its upper end to the bar b, and
resting at its lower end against a cam d¹ on the cam shaft d. The lever.c.;
also bears against the end of a lever arm e¹ on the horizontal axis e ; this.
axis is mounted lengthwise of the machine below the bed plate, and at
its back end has another arm e³ upon it, which is held up against. a.
screw by a spring g; this spring is connected to a third arm es on the
axis e, and always tends to turn the axis in such a direction as to keep >
the arm e² against the screw; the screw of screws through the bed plate
of the machine, so that by turning the screw the position of the arm e²,
and consequently of the arm e¹; which forms the fulcrum of the lever c,
can be varied. The spring 9, as before stated, not only serves to keep-
:

page_text: the arm e³ against the screw f, but also draws back the bar 6 until the
serrated feed plate a comes against the end of the slot in which it
works; the spring also serves to keep the lever c bearing against the
cam d³, and in addition draws downwards the bar b, and keeps its lower
end 6'.resting upon the cam d'; this cam is to give the requisite rising
motion to the feed plate, as is usual.
By the arrangement of mechanism above described for giving motion
to the serrated feed plate, it will be seen that when the end of the
arm e³ is near to the upper end of the lever c, only a small amount of
horizontal motion will be given to the serrated feed plate, whilst if the
screw is turned so as to lower the end of the arme¹, the amount of
horizontal motion given to the feed plate, and consequently the length
of stitch, will be increased.
I will now describe more fully the arrangement of apparatus for
raising or lifting the presser plate which holds down the fabric when the
machine is at work. In the Drawings the presser plate is marked h, and
the stem which carries it is marked h¹; this stem is circular, and moves
up and down in guides in the box or frame k, which as usual carries the
needle slide 1, and which is itself carried at the end of the arm m of the
machine; h² is a groove cut around the stem h²; into which enters a pin
on the end of a lever o; this lever turns on a pin o¹ at the back of the
box or frame k, and its end, which is towards the person working the
machine, is formed into a thumb picce, by depressing which the presser
plate can be raised off the work whenever desired, and the presser
plate will again descend on to the work so soon as the thumb piece is
relieved from pressure...
The improved construction of barrel cam is also shewn in the Draw-
ings; separate views of one of the cams is also shewn at Figures 3. In
the machine shewn at Figures 1 and 2 one such barrel cam is used
for giving motion to the shuttle, and another for giving motion to the
needle. It will be seen that by employing a cam rim carried by arms
from a central boss in the manner shewn that the bulk and weight of
metal is much less than when a cam groove is cut in a solid metal
cylinder, as heretofore.
Having thus described the nature of the Invention, and the manner of
performing the same, I would have it understood that what is claimed as
the improvements in sewing machines is,-.

page_text: 1. The improved combination of parts for feeding forward the fabric
or work which is being sewn, substantially as described.
2. The improved combination of parts for raising or lifting the presser
foot, substantially as described.
3. The improved construction of barrel cam for sewing machines, sub-
stantially as described.
In witness whereof, I, the said Norris Parmby Stockwell, have
hereunto set my hand and seal, this Sixth day of August, in the
year of our Lord One thousand eight hundred and seventy-