CERTAIN IMPROVEMENTS IN SEWING MACHINES
Year: 1877

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LETTERS PATENT to Henri Adrien Bonneville, of the British and Foreign
Patent Offices, 18, Rue de la Chaussée d'Antin, Paris, France, and 6, Picca-
dilly, in the County of Middlesex, Patent Agent, for the Invention of "CERTAIN
IMPROVEMENTS IN SEWING MACHINES." A communication from Seth Wellington
Johnson, residing in the City, County, and State of New York, United States
of America, Manufacturer.
Sealed the 17th April 1877, and dated the 12th January 1877.
COMPLETE SPECIFICATION left by the said Henri Adrien Bonneville at the
Office of the Commissioners of Patents on the 12th January 1877.
HENRI ADRIEN BONNEVILLE, of the British and Foreign Patent Offices, 18, Rue
de la Chaussée d'Antin, Paris, France, and 6, Piccadilly, in the County of Middlesex,
Patent Agent.
"CERTAIN IMPROVEMENTS IN SEWING MACHINES." A communica-
tion from Seth Wellington Johnson, residing in the City, County, and State of
New York, United States of America, Manufacturer.
This Invention relates to certain improvements in that class of sewing machines
in which a universal under feed is used, such feed mechanism consisting of a bar
that is free to move in the direction of its length and also to assume an oscillating
motion and which carries the feed dog in combination with a cam which acts on
the feed bar, and which can be adjusted so as to produce a feed motion in any
desired direction. In machines of this class the feed dog always assumes a slight
oscillating motion, and if a rectilinear seam is to be made, great care must be taken
to prevent the work from being thrown out of the right direction by the action of
the feed dog itself.
It has also been found that, particularly in sewing circular scams, the under
thread is liable to twist and curl upwards, so that it gets caught by the feed dog
and a defective seam is produced.
These defects are intended to be removed by this Invention, which consists in the
combination with a feed bar which is free to move in the direction of its length and
also to assume an oscillating motion of a rectilinear feed slide, so that the feed dog
which forms a part of the feed slide cannot be thrown out of its rectilinear path by
the oscilating motion of the feed bar.
This Invention consists also in the combination of a guard with the feed dog of
D

page_text: a sewing machine, said guard being situated between the inner surface of the feed
dog and the device which carries the under thread, so that this under thread if it
should have a tendency to curl upwards is prevented from catching in the teeth of
the feed dog.
.
This Invention consists further in a feed dog for sewing machines which is pro-a
vided with a smooth flange outside of its teeth so that if the under thread curls
upwards said flange prevents it from catching in the teeth of the feed dog.
This Invention is illustrated in the accompanying Drawings, in which Fig. 1
represents a longitudinal vertical section, Fig. 2 a horizontal section, and Fig. 3 an
inverted plan. The remaining Figures are details. Similar letters indicate corre-
sponding parts.
In these Drawings the letter A designates the cloth plate of the sewing machine
from which rises the arm or goose neck B, the face of which forms the guides for
the needle slide and for the presser slide. From the under surface of this cloth
plate project two lugs a which form the bearings for the main shaft C, from which
motion is transmitted to the working parts of the machine.
The feed bar D has its fulcrum on a screw stud b which is secured in the under
side of the cloth plate and which passes through a slot c in said feed bar, so that
this bar is free to move in the direction of its length and also to assume an oscillating
motion. The rear end of the feed bar forms a ring or eye c which embraces a
cam E. This cam consists of a cylinder which is placed in an oblique position and
feathered on a vertical arbor F. It is provided at its lower end with a circular
groove into which is fitted a ring or strap d that is pivoted to the forked end of a
lever G. This lever has its fulcrum on a stud e, which extends from a slide f that
is guided in a slotted bracket H, secured to the under side of the cloth plate, and
said slide connects by a rod I with a thumb screw J, so that by turning this thumb
screw the position of the slide f and of. its stud e is changed and thereby the length
of the stitches is regulated. The front end of the lever G is fork shaped, and it
catches over a stud g which extends from a slide h that moves in a slot in the
bracket H. From this slot extends a stud i which engages with a cam groove
formed in a disk K that is mounted on the main shaft. By turning this main shaft
therefore an oscillating motion is imparted to the lever G, whereby the oblique
cam E receives a reciprocating motion, and as this cam slides back and forth in the
eye of the feed bar D the required feed motion is produced. By turning the shaft
which carries the oblique cam E the direction of the feed motion is changed, and
by moving the fulcrum of the lever G the oblique cam E receives a reciprocating
motion, and as this cam slides back and forth in the eye of the feed bar D, the
required feed motion is produced. By turning the shaft which carries the oblique
cam E, the direction of the feed motion is changed, and by moving the fulcrum of
the lever G the throw of the oblique cam is increased or decreased and thereby the
length of the stitches is regulated as above stated.
The feed bar is made in two sections, its front section being connected to the
main section by means of a pivot j and subjected to the action of a spring which
depresses the same upon a lever L that rests upon a cam M mounted on the main
shaft. By the combined action of this cam and spring the front section of the feed
bar is alternately raised or lowered, so that the teeth of the feed dog N which rests
on said front section of the feed bar are caused to engage with the work when the
feed motion is to take place, and then said teeth are lowered out of contact with
the work in order to allow the feed dog to recede ready for a fresh forward move-
ment.
The feed dog which has been generally used in connection with this universal
feed mechanism is made circular, as shown in Fig. 4, being firmly secured to the
feed bar and made to embrace the needle throat, so that by turning the oblique cam
said feed dog is adapted to feed in any desired direction. If a rectilinear seam is
to be produced however with this feed mechanism, the work is liable to be thrown
out of the right line, and it requires constant attention to maintain the proper
direction.

page_text: In order to overcome this difficulty, the circular feed dog is removed from the
feed bar and a bracket substituted therefor, carrying a pin (see Fig. 1, 2, and 5)
which engages with a slot m in a slide O that carries the feed dog No. The slide
is fitted into a recess in the cloth plate and it is provided with projections n which
catch in grooves in the sides of said recess and prevent the slide from being displaced
accidentally. The feed dog No which is firmly secured to or made solid with the
slide O may be made square or in any desirable form, and in the example shown
in the Drawing it is provided with teeth on different sides of the needle throat.
By these means the feed slide O is compelled to move in a straight line.
°
With the feed dog is combined a guard P which is intended to prevent the
lower thread from catching in the teeth of the feed dog. In the example shown in
the Drawing this guard is made of bristles, but it may be made of any material
suitable for the purpose, and it is situated beneath the feed dog and above the
shuttle or other equivalent device which carries the lower thread. This guard is of
particular value for sewing machines with a universal feed, since in sewing round
previous curves the lower thread is liable to twist and curl up so that it catches in
the teeth of the feed dog, whereby the operation of the machine is disturbed. In
some cases however, even in making straight seams, the lower thread has a tendency
to curl up, particularly if it is twisted hard, and this guard is therefore of advantage
for all sewing machines with two threads.
In order to prevent the lever thread from catching in the teeth of the feed dog,
said feed dog is provided with a smooth rim p (see Fig. 4) outside of the teeth. If
a feed dog of this kind is used the guard may be omitted.
Having thus described the nature of the said improvements and the manner of
carrying them into effect, what I claim is,-
1. The combination with a feed bar which is free to move in the direction of its
length and also assume an oscillating motion of a rectilinear feed slide, constructed
and operating, substantially as and for the purpose shown and described.
2. The combination of a guard P with the feed dog of a sewing machine, said
guard being situated between the inner surface of the feed dog and the device
which carries the under thread, substantially as and for the purpose set forth.
3. A feed dog for sewing machines which is provided with a small flange or
rim outside of its teeth, substantially as and for the purpose shown and described.
In witness whereof, I, the said Henri Adrien Bonneville, have hereto set my
hand and seal, this Third day of January, in the year of our Lord One
thousand eight hundred and seventy-seven.
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E. (L.S.)
H. BONNEVILLE.