IMPROVEMENTS IN SEWING MACHINES
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by John Victor Boesiger at the Office
of the Commissioners of Patents, with his Petition, on the 26th December
1863.
I, JOHN VICTOR BOESIGER, of the Firm of Messieurs John Boesiger and
Sons, of Roggwyl, in the Canton of Bern, in the Republic of Switzerland,
and of 2, Thavies' Inn, Holborn, in the City of London, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN SEWING MACHINES,"
to be as follows:
This Invention relates more particularly to that class of sewing machines
wherein a shuttle is employed in combination with a straight needle for
producing the stitching, and is partly applicable also to other descriptions of
sewing machines. According to this Invention it is proposed to make the
arm or cloth-supporting portion of the machine partly of wrought iron and
partly of cast iron, rivetted together, whereby greater strength and lightness
are obtained than when cast iron only is employed. The main driving shaft
is carried in bearings in the overhanging bracket arm of the machine standard,
and is driven by hand or otherwise. Near to the rear end of this shaft is
keyed a cylindrical grooved cam, which actuates a lever connected with the
stem of the shuttle drum; the front edge of this cylindrical grooved cam is
also cam-shaped, and actuates a small lever arm, which serves to take up the
slack of the needle thread, this lever being pushed forward by the cam surface
and then drawn back, so as to take up the slack by an adjustable spring.
A grooved pulley is fitted on to the end of this lever, round which the thread
is passed in order to reduce the friction; or a ring may also be employed in

page_text: place of the roller, and the thread passed through it. The needle slide is
actuated by a disc having a proper cam groove on its face keyed on to the
extreme front end of the driving shaft, an antifriction roller in the needle slide
working in the cam groove above referred to; this groove is so shaped as to
cause the needle to descend and enter the cloth or other material slowly, and
then to complete its downward motion more rapidly. The eye of the needle
is made much further from the point than heretofore in shuttle machines, and
the groove on that side of the needle next the shuttle is carried down closer
to the point than in the ordinary needles when used for sewing cloth. Inside
the shuttle race there is fitted on the side next which the needle works an
adjustable plate provided with one, two, or more deep vertical grooves, in
which the needle enters, and which serve to ensure the proper presentation of
the loop to the shuttle. When a number of these grooves are employed they
are made to suit needles of different sizes, the plate being adjusted accordingly.
The shuttle is made to work with its point outwards or from the machine, so
that after it has passed through the loop of the needle thread, and when the
material is being fed along in a line with the arm for the next stitch, the
thread will extend nearly in a direct line with the motion of the material to
the shuttle, in place of forming an acute angle, as is the case when the front
of the shuttle is turned inwards or towards the machine, and consequently
there is less drag or strain on the shuttle thread. In order to equalize as
much as possible the drag or friction on the shuttle thread as it is being drawn
off the spool, it is proposed to make an additional and larger hole in the shuttle
in a position at right angles to the ordinary tension holes, and to pass the
thread down through this hole after it has been drawn through one of the
ordinary tension holes before it is repassed through one or more of the other
holes. By this means the variation in the angle or direction of the thread in
the different stages of its unwinding in the different positions of the shuttle
itself is obviated. In combination with this arrangement it is further proposed
to employ a wire curved at each end, but having a straight portion in the
middle, under which wire the thread is passed immediately on leaving the
spool, such wire being let into notches or recesses in the back of the shuttle,
into one of which it is secured by a hinge pin, its object being to equalize the
drag on the thread from whatever part of the spool it be drawn off.
inclined projection is fitted or formed in the front end of the shuttle race,
against which the driver works, and is by it pushed in a lateral direction, so as
to nip or press against the shuttle, and thereby prevent any shaking or jarring
at the end of the shuttle's traverse after it has passed through the loop, that is,
at the end of the forward stroke, and at the commencement of the back stroke
All

page_text: of the shuttle. Another inclined projection is formed on the under side of the
cloth plate to prevent the rising or vertical vibration of the shuttle at the
forward end of its stroke. When it is desired to feed in either of two
directions at right angles to each other, two separate feeding plates are
employed acting upon the upper surface of the cloth or material, the head of
the bracket being provided with two corresponding notches or grooves to
receive either of the feeders which may be required. These feeders receive a
vertical and horizontal to-and-fro motion, and are retained in their holding
grooves by the head of the spring which imparts to them their back move-
The vertical motion is obtained from studs or rollers on the needle
cam acting upon a forked lever, which works between two pins in the stem of
the feeding plate, and is hinged to a spring bracket, in order to render its
motion more easy, the downward motion or pressure on the cloth is obtained
from an adjustable blade spring, which bears upon either one or the other of
the stems of the two feeding plates, as required. The forward or feeding
movement is imparted to each of the feeders by a special cam surface in the
centre of the needle cam.
The feeding plates are lifted from off the work when required by a small
bell-crank lever, which is locked in its elevated position by a spring sneck or
catch, the same lifting apparatus serving for both the feeding plates.