IMPROVEMENTS IN SEWING MACHINES AND IN RENDERING THEM SELF-ACTING
Year: 1877

page_text: LETTERS PATENT to Alexander Watkins, of 59, Carey Street, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN SEWING MACHINES AND
IN RENDERING THEM SELF-ACTING."
Sealed the 25th January 1878, and dated the 19th November 1877.
PROVISIONAL SPECIFICATION left by the said Alexander Watkins at the
Office of the Commissioners of Patents on the 19th November 1877.
ALEXANDER WATKINS of 59 Carey Street in the County of Middlesex.
PROVEMENTS IN SEWING MACHINES AND IN RENDERING THEM SELF-ACTING."
« IM-
My Invention has for its object the construction of sewing machines in such a
manner as to diminish friction in their working and consequently the power required
to work them, and also the adaptation and application to such machines of
mechanism by means of which they may be rendered self-acting.
And my Invention consists in constructing the machine throughout in such a
manner as to diminish friction in the action of the working parts by diminishing
the area of the surfaces in contact, and making these parts of steel and other hard
materials adapted to resist wear in place of iron and the materials in ordinary use
in sewing machines.
With reference to particular parts of the machine, my Invention consists in
placing the pivot of the lever bar for working the needle at or near the centre
thereof, so as to balance such lever bar, and thereby diminish the power required for
working the needle through or by means of such bar, the end of which is connected
to a light rod, which receives a crank motion of suitable throw to work the needle
as required, the shaft working the looper being driven in the ordinary manner.
This shaft is mounted so as to turn in hard steel bearings at each end, the frictional
surfaces of which bearings and such parts of the shaft are of much smaller area than
usual.

page_text: The presser bar is also arranged so as to diminish friction in its working, by
dispensing with the ordinary spiral spring, and forming the required connection
by making the end of a flat spring to enter an aperture in the bar, which is guided
in its slight vertical movements by having slots in it through which pass fixed studs
which serve as guides.
There is also a spring brake and regulator for stopping and regulating the motions
of the machine as required. This consists of a vertical rod with a screw on it, by
turning which screw the bottom end of the rod is caused to press a brake on to a
small wheel on the main shaft, and produce the required amount of stopping or
retarding friction on the wheel, such wheel being released from the action of the
brake by the reaction of a spring on the pressure being removed from the brake, by
turning the screw back again and raising the vertical rod.
There is also an arrangement for passing the thread direct from the bobbin to the
needle, whereby friction is prevented, the requisite tension of the thread being
produced by means of a spring on which the bobbin rests such spring pressing the
bobbing upwards against a button or collar, which is screwed up or down as
required in order to regulate the said tension.
The machine constructed in the manner above stated so as to reduce friction in
the working parts, can be rendered self-acting by combining there with driving
mechanism consisting of a spring acting on a parabolic spiral, having on its shaft a
spur wheel gearing with a pinion, on the axis of which is a wheel gearing with a
pinion on the same axis as the driving wheel of the machine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Watkins in the Great Seal Patent Office on the 18th
May 1878.
ALEXANDER WATKINS of 59 Carey Street in the County of Middlesex.
PROVEMENTS IN SEWING MACHINES AND IN RENDERING THEM SELF-ACTING."
" IBI-
My Invention of "Improvements in Sewing Machines and in Rendering them
Self-acting" has for its object the construction of sewing machines in such a manner
as to diminish friction in their working and consequently the power required to
work them and also the adaptation and application to such machines of mechanism
by means of which they may be rendered self-acting.
And my Invention consists in constructing the machine throughout in such a
manner as to diminish friction in the action of the working parts by diminishing
the area of the surfaces in contact and making these parts of steel and other hard
materials adapted to resist wear in place of iron and the materials in ordinary use
in sewing machines.
With reference to particular parts of the machine my Invention consists in
placing the pivot of the lever bar for working the needle at or near the centre
thereof so as to balance such lever bar and thereby diminish the power required
for working the needle through or by means of such bar the end of which is
connected to a light rod which receives a crank motion of suitable throw to work
the needle as required. The shaft for working the looper is driven in the ordinary
manner. This shaft is mounted so as to turn in hard steel bearings at each end,
the frictional surfaces of which bearings and such parts of the shaft are of much
smaller area than usual.
The presser bar is also arranged so as to diminish friction in its working by
dispensing with the ordinary spiral spring and forming the required connection by
making the end of a flat spring to enter an aperture in the bar which is guided in
its slight vertical movements by having slots in it through which pass fixed studs
which serve as guides.
There is also a spring brake and regulator for stopping and regulating the motions
of the machine, as required. This consists of a vertical rod with a screw on it by
turning which screw the bottom end of the rod is caused to press a brake on to a small
wheel on a shaft in gear with the main shaft and produce the required amount of
stopping or retarding friction on the wheel such wheel being released from the
action of the brake by the reaction of a spring on the pressure being removed from
the brake by turning the screw back again and raising the vertical rod.
There is also an arrangement for passing the thread direct from the bobbin to
the needle whereby friction is prevented the requisite tension of the thread being
produced by means of a spring on which the bobbin rests such spring pressing the
bobbin upwards against a button or collar which is screwed up or down as required
in order to regulate the said tension.
The machine constructed in the manner above stated so as to reduce friction in
the working parts can be rendered self-acting by combining therewith driving
mechanism consisting of a spring acting on a parabolic spiral having on its shaft a
spur wheel gearing with a pinion on the axis of which is a wheel gearing with a
pinion on the same axis with the driving wheel of the machine. Or the driving
mechanism may be otherwise constituted as herein-after stated.
Having thus stated the nature of the said Invention I will proceed to describe
more particularly in what manner the same is to be performed by the aid of the
accompanying Drawings in which is represented a machine constructed in the
manner above referred to.

page_text: Figures 5. 6 and 7 represent detached parts of the machine. In these several
Figures the same letters of reference indicate corresponding parts.
A A are the table and standards or frame of the machine, B is the main or
driving shaft, to which manual or mechanical power is to be applied. C is a spur
wheel on this shaft gearing with the wheel D to which is connected the light rod E
which is jointed to the lever bar F for working the needle. This lever bar F has
its fulcrum at G which it will be seen is about midway between the two ends of
the lever thereby balancing the lever or nearly so and diminishing the power
.required to work it. The requisite throw for working the needle H is obtained by
connecting the rod E to the wheel D in the manner shewn in Fig. 2 whereby the
end of the rod has a suitable crank motion imparted to it. By this arrangement it
will be seen that the power required to work the needle from the driving shaft is
greatly diminished.
I is the looper shaft which is driven by the wheel D and is mounted so as to
turn in hard steel bearings. This shaft is formed with a small journal at each end,
as shewn in Fig. 5 the journal at the end nearest the wheel D passing through a
steel collar K inserted in the bearing of the shaft and the journal at the other end
having on it the eccentric for driving the looper and working in a steel collar
inserted in the bearing L. In each case the frictional surface in contact with the
journal is only of the width of the collar in which the journal works. Fig. 6 shews
the steel collar K and Fig. 7 the steel collar in the bearing L. By forming and
mounting the shaft in this manner a great diminution of bearing and frictional
surface is secured and wear of the parts is prevented by making them of steel or
other suitable hard material.
M is the presser bar the friction in the working of which is diminished by
substituting for the ordinary spiral spring round a vertical spindle a flat spring N the
end of which is passed through an aperture in the bar in which are formed slots to
admit of the slight vertical movements of the bar on fixed studs which with the
slots serve as guides for the bar.
O is a vertical screw rod with a button at the top by turning which the rod will
be screwed down on a spring brake P and cause the same to press on a small
wheel on the shaft of the wheel D and thereby stop or retard the motion of the
machine as may be required. On raising the rod O by turning the screw in the
reverse direction the wheel Q will be released from pressure by the reaction of the
spring fixed to the brake P.
R is the ordinary bobbin for supplying the thread to the needle. This bobbin is
under my Invention arranged so as to admit of the thread being passed to the
needle in a more direct manner than usual thereby preventing the friction due to
the ordinary arrangements of passing the thread through intermediate guides.
The bottom flange of the bobbin rests on a spring S and the tension of the thread
is regulated as required by pressing the said flange on to the spring by means of a
button T at the top of the bobbin.
U is a fly wheel for equalizing the motion of the machine.
From the foregoing description it will be readily understood that the machine is
so constructed throughout as greatly to reduce the friction of the working parts and
consequently to diminish in the same proportion the amount of power required to
work the machine thereby greatly facilitating the means of rendering the machine
self-acting when required. And this is the more important because while on the
one hand the labour of working machines of the ordinary construction has been
found to be highly injurious to female workers on the other hand the amount of
power required has made it difficult to adapt self-acting means for working them.
But machines constructed in the manner above described can be rendered self-
acting by applying thereto simple driving mechanism which may consist of a
wound-up spring acting on a parabolic spiral having on its shaft or axis a spur wheel
gearing with a pinion on the axis of which is a wheel gearing with a pinion on the
same axis with the driving wheel of the machine. Or instead of the parabolic spiral
and drum a graduated spring may be connected to the boss of the driving shaft

page_text: the other end of the spring being fixed to the frame a toothed wheel on the driving
shaft gearing with the pinions and wheels as above stated. Or, if preferred, the
shaft may be driven by means of a weight suspended by a cord or chain from a
drum on which the main toothed wheel works. Or the shaft may be driven by
means of a spring which is raised and put in tension by winding a chain or cord
the reaction of the spring causing the shaft to be driven as required.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed I hereby declare that what I claim as of my Invention
is
First. The general arrangement and construction of the machine in its various
parts so as to reduce friction in the working thereof as herein-before described.
Secondly. The arrangement described for balancing and working the lever bar for
working the needle.
Thirdly. The mode described of forming and mounting the shaft for working the
looper.
Fourthly. The arrangement described for working the presser bar.
Fifthly. The spring brake for stopping and regulating the motions of the machine,
as herein-before described.
And lastly. The driving mechanism consisting of a spring with a parabolic spiral
or a graduated spring or a weight or spring and spur gearing as herein-before
described.
In witness whereof I the said Alexander Watkins have hereunto set my
hand and seal the Seventeenth day of May in the year of our Lord
One thousand eight hundred and seventy-eight.
Witness
WILLIAM SPENCE
8, Quality Court
Chancery Lane,
ALEX³, WATKINS. (L.S.)