Improvements in Sewing Machines.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Sewing Machines.
CHARLES WALTER VOSPER, 3, Nelson Terrace, Newport Road, Barnstaple,
Engineer, do hereby declare the nature of this invention to be as follows:-
I take an ordinary sewing machine which works either with a rotary hook,
rotary, or reciprocating shuttle. having its path or race in a line with the feed
motion and adapt it in such a way that by causing the needle bar of such machine
to have a vibrating or lateral motion to the line of the driving spindle it shall
produce a back stitch. To produce this I place on the driving spindle a pinion
wheel which will gear into a larger toothed wheel fixed on a spindle with bearings
parallel to the said driving spindle, on this spindle I place a cam which will have
one half of its periphery projecting somewhat beyond that of the other half or I
may make a hollow cam of the same shape this movement being connected to
certain links or levers and connected again to the needle bar will cause a vibrating
motion to it, and make the stitches alternate as the work is fed along and pro-
ducing what is known by seamsters as a back stitch. This lateral motion of the
needle bar may likewise be produced by a cross cam which I shall fix on the driving
spindle and arranged with certain links or levers very similar to those used in con-
nection with the cog wheels.
1
I, CHARLES WALTER VOSPER, of 3, Nelson Terrace, Newport Road, l'arnstaple,
Engineer, do hereby declare the nature of this invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The object of the present invention is to construct a sewing machine that will
make a hack stitch as well as doing the ordinary plain lock-stitch.
Hitherto sewing by a lock-stitch machine on materials of an elastic nature has
been a failure in account of its rigidity-both the upper and lower threads of the
stitch being unstretchable in lock-stitch machines as now constructed, and the
stitches following one another in a straight line, without going back over, or over-
lapping. When the seam of materials is cut on the bias-as the leg seams and
seat seams of trousers-the present sewing machines cannot be used with safety,
and are not used except in work of a very cheap description. This is because the
sewing will not stretch with the material, and on a very slight strain the stitches
break and the seams open. Therefore this work is done by hand. The hand
work is done by what is known as the back stitch. The operator uses the ordinary
[Price 8d 1

page_text: sewing needle and starts by making one stitch through the material; he then goes
back one half of the distance from the point at which he started and makes another
stitch of the same length as the first. He then commences the third stitch at
the point at the end of the first stitch and so on. Up to now machine work has
not been able to compare with hand work for strength and elasticity. My inven-
tion will now enable the back stitch to be done by machine in quite as simple a
manner as the work of the ordinary sewing machine. It also combines the
advantages of the lock-stitch being in fact a back-lock-stitch sewing machine;
the stitches being looped and intertwined into one another as shown in Fig. 6 of
the drawings. The form of this stitch is far stronger and more elastic than in work
at present done either by hand or by machine. My machine can also be adjusted
instantly at the will of the operator to do the ordinary forward stitch of the
common lock-stitch machine.
The principle of my invention is applicable to machines for the use of a tailor,
dressmaker, shirtmaker, glover, tie-maker,--in short for every kind of work in
which material cut on the bias has to be sewn, or for any other sewing work on
material of an elastic nature.
The invention may be applied to an ordinary rotary hook, rotary shuttle, or an
oscillating or reciprocating shuttle sewing machine, the movements of such hook
or shuttle being in a path parallel to the line of the feed motion.
The accompanying drawings illustrate a suitable manner of carrying the inven-
tion into effect, as applied to a sewing machine having a reciprocating rotary
shuttle carrying the under thread.
In these drawings:
Fig. is a side elevation of the machine with my invention applied thereto.
Fig. 2 is an end elevation of such machine with the front plate removed so as to
show the means for actuating the needle bar.
Figs. 2 and are end views showing the needle at the opposite positions of its
horizontal travel and the thread passing from same under the cloth plate.
Fig. 3 is a plan view of such machine.
Fig. is a side elevation, and
T
Fig. 5 is a plan view on an enlarged scale of suitable means for imparting the
reciprocating horizontal motion to the needle bar in a line at right angles to the
ordinary vertically reciprocating movement which is imparted to such bar so as
to produce the back stitch.
Fig. 6 shows the form of stitch which is produced by the improved machine.
Fig. 7 shows the form of stitch produced when the machine is working as an
ordinary lock-stitch machine.
The means employed for imparting the vertically reciprocating motion to the
needle bar A, and the rotary reciprocating motion to the shuttle 1, may be of any
known or desired construction. The arrangement shown in the drawings for pro-
ducing the vertically reciprocating motion of the needle bar consists in mounting
a dise C on the end of the driving shaft 1), which may be driven either by hand
or power as desired and connecting such disc to a collar secured to the needle
bar A, by means of a connecting rod E.
The rotary motion of the driving shaft 1) is transmitted by a connecting rod F
to a shaft G, mounted in suitable bearings beneath the bed plate H of the machine,
in such a manner as to impart a reciprocating rotary motion to such shaft G, the
forward end of which is fitted with a carrier for the shuttle B.
In addition to the vertically reciprocating movement imparted to the needle
bar A, such bar has a horizontally reciprocating movement imparted to same at
right angles to the vertical movement. The extent of the horizontal movement
iniparted to the needle har is indicated by the dotted lines in Figs. 2, 24, and 2º,
but same may be varied by means to be hereinafter described so as to regulate the
length of the back stitch as required. In order to impart the reciprocating
horizontal movement to the needle bar A, same is mounted in a slotted frame I,
the length of such slots being sufficient to allow such bar to be reciprocated forward

page_text: and backward in such a way that one stitch will be formed when it makes its down-
ward motion nearest to the operator on the line in which the work is travelling,
while the next stitch will be formed further towards the other side of the frame
but in a straight line with the seam so that as the work is passed along by the feed
the stitches produced overlap each other to the extent of about half the distance
between the two last stitches formed as shown in Fig. 6, where r is the upper
thread and y the under thread, but this amount of overlap may be varied at the
will of the operator.
In order to impart the necessary horizontally reciprocating motion to the needle
bar at the desired times I employ links KK, which are connected together by a
rod L at one end, while the needle bar A is free to slide through holes formed to
fit such bar in the other end of such links.
A horizontally reciprocating movement is imparted to such bar L, and con-
sequently to the links K K, and the needle bar A passing through the links. The
required motion is obtained by means of cranks M M attached to a spindle N, to
which a rocking motion is imparted by another crank 0. pivotted to a link 1',
jointed to a lever or rod Q, which is bent as shown in Fig. so as to pass back to
a hanging link or plate R. to which it can be clamped by means of a butterfly nut S
working on a screw which passes through a curved slot T in the plate R so that
the point of attachment of the lever or rod Q to the hanging link or plate R can
be varied, and the horizontally reciprocating movement imparted to the needle
bar A be adjusted as desired, this movement taking place whilst the needle is up
clear of the work, the raising of such point of connection reducing the length of
motion whilst the lowering of same will increase the length of motion.
When the point of attachment is raised to the highest point the machine will
do plain sewing like an ordinary lock-stitch machine as shown in Fig. 7, which
is a diagrammatic view of the form of stitch then made. The plate R has an
index marked thereon so as to show the operator how to regulate the length of
motion as compared with the length of stitch, but it must be understood that in
all cases where a back stitch is required the length of the horizontal movement
of the needle bar must exceed that of the feed.
The driving shaft D is fitted with a cross cam U. shown in detail in Figs. 4
and 5, by means of which the necessary reciprocating movement is imparted to
plate R. Instead of employing the cam shown, the necessary horizontal reciprocat-
ing movement may be imparted to the needle bar A by means of cog wheels or in
any other suitable manner, but as those means for producing such reciprocating
motion in other kinds of sewing machines are well known they need not be herein
described.
In Figs. and 2" I show the movement of the upper thread in two different
positions, Fig. 2 shows the position of the thread when the needle is about to make
its descent at a point nearest to the operator, and the thread has been drawn over
the shuttle B and is formed into a stitch at the cloth plate. The work having been
fed forward by the feeder g, the thread naturally stands at an angle from the
point of formation of the stitch to the eye of the needle. The dotted line e shows
the angle of the thread when the, needle has arrived at a point ready to pass to
point previous to the work being fed along..
In Fig 2 the position of the dotted and plain lines is reversed, this fig. showing
the position of the threads when the needle is ascending and just before the thread
is drawn up over the shuttle at e. The feeding operation has not taken place
consequently the angle at which the thread stands differs from that shown in
Fig. 2. The dotted line f shows the thread at the same angle as in Fig. 24, because
the needle has passed to the highest point and moved over to the opposite side,
the work having been fed forward one stitch and the needle, being ready to descend
to form the next stitch. The passage of the thread over the shuttle is the same as
in all other lock-stitch machines.
I am aware that a back stitch is not new and that several kinds of sewing
machines have been devised for the purpose of producing such a stitch, but the

page_text: construction of such machines differs from that herein above described. It will
be seen that my machine does not make what is known as the buttonhole stitch,
which latter form of stitch must be produced by a shogging operation either by the
needle or feed across the line of the direction in which the work travels. It will
also be seen that the motions introduced by me differ in many points from those
employed in other machines to produce buttonhole sewing, for instance the disc C
shown at Fig. 2 carries a pin which holds the connecting rod E close against its
face, the other end of the connecting rod E is likewise firmly held against the
collar a attaching it to the needle bar A, whereas if the needle bar shogged across
the feed line this part of the machine would have to be of different construction.
Further the rocking shaft N Figs. 1 and 2 and the cranks M M and the bar L with
the links KK which I employ would not be required to impart a sideway motion
to the needle bar, so that there is no equivalent in any sewing machine to those
motions. It is impossible for my machine to work if the needle bar were shogged
across the line of the shuttle race and I therefore make a shuttle race in a line
parallel with the shogging motion. I believe this to he new, as in all other
inachines of which I am aware use is made of a race and shuttle situated trans-
versely in relation to the shogging motions unless the shogging is done across the
line of the feed when in the latter case a parallel race may be used if also fixed
across the line of the feed.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed. I declare that what
I claim is:
In a sewing machine:.
1. The combination of a needle bar and a drop or under feed to which needle
bar a horizontally reciprocating motion is imparted in a line at right angles to the
ordinary vertically reciprocating motion imparted to such needle bar in a straight
line parallel to the line of the said under feed.
2. The combination of a needle bar and a drop or under feed to which needle
bar a horizontally reciprocating motion is imparted in a line at right angles to the
ordinary vertically reciprocating motion imparted to such needle bar in a straight
line parallel to the line of the said under feed, such needle bar being jointed to
the driving spindle by a link or connecting rod E connected to a disc and work-
ing in guides or links K K and a frame slotted to allow such needle the traverse
required.
3. The combination of link connections K, K, with a spindle or bar L to which
two slotted cranks are joined the said slotted cranks being fastened to the rocking
shaft N which is itself connected to the parts to which a vibrating motion is
imparted by the cross or switch cam U on the driving spindle, substantially as
described.
4. In a lock-stitch sewing machine the combination of link connections K, K,
with a spindle or bar L to which two slotted cranks are joined the said slotted
cranks being fastened to the rocking shaft N which is itself connected to the parts
to which a vibrating motion is imparted by the cross or switch cam U on the
driving spindle, with a rotary hook, or a rotary or oscillating shuttle which has a
path or race parallel to the line of the feed, substantially as described.
Dated this 6th day of June 1898.
ALLISON BROS.,
Agents for the Applicant.