IMPROVEMENTS IN SEWING MACHINES
Year: 1874

page_text: LETTERS PATENT to John Asten, of Colchester, in the County of:
Essex, Engineer, for the Invention of "IMPROVEMENTS IN SEWING
MACHINES."
Sealed the 3rd July 1874, and dated the 12th May 1874.
PROVISIONAL SPECIFICATION left by the said John Asten at the
Office of the Commissioners of Patents, with his Petition, on the
the 12th May 1874.
I, JOHN ASTEN, of Colchester, in the County of Essex, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS:
IN SEWING MACHINES," to be as follows:-
This Invention relates to the shuttle motion of sewing machines, and
also to the feed motion, which latter is applicable to sewing machines of
all kinds.
The improved shuttle motion consists of a horizontal vibrating lever
working on a fixed centre underneath the bed plate of the machine.
The front end of this lever is slotted to receive a pin attached to the
:

page_text: shuttle driver, whilst in the opposite end of the said lever there is formed
a socket for the reception of a ball, which is loosely fitted on to a vertical
rocking arm, such arm being secured to a rocking shaft working in
bearings underneath the bed plate. The rear end of the said rocking
shaft is cranked, and to this crank there is connected one end of an
eccentric rod, which receives motion from an eccentric on the rear end
of the driving shaft, which works in bearings in the overhanging bracket
or fixed arm of the machine. As this shaft revolves it imparts through
the eccentric and rod a rocking motion to the shaft, below which motion
is transmitted by the vertical rocking arm and ball-and-socket joint to
the lever which actuates the shuttle driver.
The improved feed motion, which is of the class known as the "four-
motion feed," consists of a feed bar having a projecting, roughened, or
serrated surface, and working by a slot on a fixed pin, a spring serving
to return the bar after each stitch, as is well understood. This feed bar
is held up to its work whilst in the act of feeding by resting upon the
end of a vertical vibrating arm working loose on a fixed stud carried by
a lug on the under side of the bed plate.
On the front end of the before-mentioned rocking shaft underneath
the bed plate there is fixed a three-armed lever, one arm (the end of
which is bevelled or inclined) by striking against a corresponding incline
on the under side of the feed bar, or against an antifriction roller fitted
therein, serves to give the feed motion thereto. Another arm fitted with
a pad of india-rubber or other sound deadening material bears against
and pushes back the vertical vibrating arm, thereby allowing the feed
bar to descend whilst making the back or return stroke. The third arm
comes into action just as the feed bar has completed its back stroke, and
by striking against a tail-piece on the lower end of the vertical vibrating
lever causes that lever to move forward again, and thereby to lift the
feed bar in readiness for the next feed.

page_text: eccentric rod, which receives motion from an eccentric on the rear end
of the driving shaft, which works in bearings in the overhanging bracket
or fixed arm of the machine. As this shaft revolves it imparts through
the eccentric and rod a rocking motion to the shaft, below which motion
is transmitted by the vertical rocking arm and ball-and-socket joint to
the lever which actuates the shuttle driver.
The improved feed motion, which is of the class known as the "four-
motion" feed, consists of a feed bar having a projecting roughened or
serrated surface and working by a slot on a fixed pin, a spring serving
to return the bar after each stitch, as is well understood. This feed bar
is held up to its work whilst in the act of feeding by resting upon the
end of a vertical vibrating arm working loose on a fixed stud carried by
a lug on the under side of the bed plate.
On the front end of the before-mentioned rocking shaft underneath
the bed plate there is fixed a three-armed lever, one arm (the end of
which is bevelled or inclined) by striking against a corresponding incline
on the under side of the feed bar or against an antifriction roller fitted
therein serves to give the feed motion thereto. Another arm fitted with a
pad of india-rubber or other sound-deadening material bears against and
pushes back the vertical vibrating arm, thereby allowing the feed bar to
descend whilst making the back or return stroke. The third arm comes
into action just as the feed bar has completed its back stroke, and by
striking against a tail-piece on the lower end of the vertical vibrating
'lever causes that lever to move forward again, and thereby to lift the
feed bar in readiness for the next feed.
And in order that my said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the explanatory Sheet of Drawings
hereunto annexed, the same letters of reference indicating corresponding
.parts in all the Figures.
Figure 1 of my Drawings represents a side elevation and partial
section of a sewing machine having my improvements applied thereto.
Figure 2 is a corresponding plan of the under side of the bed plate of
the machine.
Figure 3 is a partial front elevation and transverse section of the said
machine, showing the feed mechanism; and Figure 4 is a similar trans-
· verse section showing the feed mechanism in a different position..

page_text: The detail Figure 5 represents the "take up" spring for the needle-
thread detached from the machine.
A is the bed plate of the sewing machine and B the fixed overhanging
bracket arm carrying in suitable bearings therein the driving shaft C of
the machine. This shaft at its front end carries a disc D and crank pin a,
which latter works in a slotted cam E attached to the needle slide F for
the purpose of actuating the same, as is well understood.
On the rear
end of the driving shaft there are fitted the driving pulley G, fly wheel H,
and an eccentric at I. This eccentric serves to actuate the shuttle and
the feed bar of the machine through mechanism, which I shall now
proceed to describe. K is an eccentric rod connected in the usual
manner by a strap to the eccentric. I, and coupled at its lower end to the
pin of a crank L formed on or secured to the rear end of a rocking shaft
M, which rocks in bearings fitted in the under side of the bed plate.
The shuttle motion is derived from this shaft by means of a short vertical
rocking arm or lever N fixed to the said shaft, which lever at its upper
end enters loosely a metal ball or sphere 6 contained within a socket c
formed on the rear end of the horizontal vibrating lever O. This lever
vibrates on a fixed fulcrum at a secured to the under side of the bed
plate, and is extended forward far enough to reach the shuttle driver e
(see Figs. 1 and 2). A slot is formed in the front end of the said
lever, which slot engages with a pin projecting from the under side of
the shuttle driver.
From the arrangement above described it is obvious that the
"continuous rotatory motion of the main driving shaft C will produce a
rocking motion in the shaft M, which motion is transmitted by the lever
arm N and ball-and-socket joint or coupling to the horizontal lever O,
which imparts the requisite reciprocating traverse to the shuttle driver
within its "race" or guides 9, 9.
}
:
The feed motion is derived in the following manner from the rocking
shaft M, reference being had more particularly to Figures 3 and 4 of my
Drawings:-P represents the feed bar of a-"four-motion" feed; it is
roughened or serrated at the part which catches the cloth, as is well
understood, and is supported at one end by a pin i which passes through
a slot in the bar, and is screwed into a portion of the bed plate. The
opposite.end of this feed bar is supported or held up by simply resting
upon the upper end of a vertical vibrating or swinging arm Q, which

page_text: works on a fixed centre at k. A bevelled or inclined step 7 is made in
the under side of the feed bar, that is to say, the said bar is of two
thicknesses in order to allow it to assume an elevated and a depressed
position alternately, as I shall now proceed to describe. When the
thicker or most projecting part of the feed bar rests upon the end of the
arm the said bar will be sufficiently elevated to press against the
under surface of the cloth and move it along when making the forward
stroke in its clevated position, but when the thinner or least projecting
portion rests upon the end of the lever Q then the feed bar will obviously
have dropped sufficiently to free it from contact or nearly so with the
cloth, and allow it to make the back or return stroke without imparting
any motion to the cloth.
In both my Drawings Figures 3 and 4 I have shown the feed bar in its
clevated position, but in Figure 3 it has just completed its forward stroke
and is about to drop preparatory to making the back stroke, whereas in
Figure 4 the bar has completed the back stroke by the action of the usual
spring, and is elevated in readiness to commence the forward stroke
again. The upward and forward motions of the feed bar, as well as the
downward motion are derived from the three arms R, S, and T, mounted
on the front end of the rocking shaft M. The feed bar is bevelled or
inclined at m, and a corresponding incline n is formed in the end of the
arm R. When in the position shown in Fig. 4 the upward motion of
the end of the arm R will by its incline action cause the feed bar to
move forward in the direction of the arrow until the two inclined
surfaces have passed cach other, which is the position shown in Figure 3.
By a slight continuance of the upward movement of the arm R the
padded end of the arm S will be brought into contact with the upper
part of the supporting arm Q, and will push it under the thinner or less
protruding part of the feed bar, thereby allowing such bar to drop in pro-
portion to the depth of the step or incline therein and make its return
or back stroke. On the motion of the rocking shaft being reversed the
padded end of the third arm T is brought in contact with the tail of the
supporting lever arm Q, and causes the upper end of that lever to move
along the step or incline in the feed bar, thereby lifting it so as to
cause it to strike the cloth again, and the motions are repeated at cach
oscillation of the shaft M.
The stitch regulating cam is shown at U, Figures 3 and 4, and the
take-up" spring V for the needle thread is shown at Figure 5. It is

page_text: mounted on a plate W, which is attached by screws at the screw holes
o, o, to the front of the fixed bracket arm.
Having now described and particularly ascertained the nature of my
said Invention and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,―
First. The peculiar combination and arrangement of mechanism for
actuating the reciprocating shuttles of sewing machines, as herein-before
described and illustrated by Figures 1 and 2 of the Drawings hereunto
annexed.
Secondly. The peculiar combination and arrangement of mechanism
for actuating the feed bar of a sewing machine, as herein-before described
and illustrated by the Drawings hereunto annexed.
In witness whereof, I, the said John Asten, have hereunto set my
hand and seal, this Fifth day of November, in the year of our
Lord One thousand eight hundred and seventy-four.
JOHN A STEIN