Improvements in Sewing Machines.
Year: 1892

page_text: Date of Application, 23rd May, 1892-Accepted, 18th Feb., 1893
COMPLETE SPECIFICATION.
Improvements in Sewing Machines.
We, VACLAV TOMSA, Holeschowitz, Prague, Austria, Mechanic, JOSEF
SPIDRA, Holeschowitz, Prague, Colonial Dealer, BOHUNUL GUDIKAR, Sugar
Manufacturer, Prague, and KAKEL F. MAYR, Weinberg, Prague, Sugar-factory
Manager, 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 :-
Our invention relates to a new type of sewing machine which makes two
stitches for each revolution of the driving wheel. The chief differences of con-
struction between our machine and the older constructions, are, that
(1st) The shuttle is pointed at both ends.
(2nd) The horizontal driving shaft is made in two parts which are independent
of each other.
(3rd) The new machine makes two stitches for each revolution of the driving
wheel, instead of only one as formerly.
(4th) The mechanism is oscillatory in its action, yet, notwithstanding this, the
work always progresses in the same direction.
And in order that our invention may be properly understood, we have hereunto
appended four explanatory sheets of drawings, whereon :-
Fig. 1 is a longitudinal section of the machine.
Fig. 2 is a front view of the needle-bar casing.
Fig. 2 is a vertical section of the needle-bar casing, showing the interior
mechanism.
Fig. 3 is a view of the head of the machine.
Fig. 4 is a side elevation of the machine.
Fig. 5 is a view of the sewing table, as seen from below.
Fig. 6 shows in detail the eccentric-lever for moving the feed plate and apparatus
for regulating the length of the stitch.
Fig. 7 is a view of the eccentric, on which said lever works.
Fig. 8 shows, in detail, front and side views, the eccentric-lever for moving the
shuttle.
Fig. 9 shows the toothed sector and pinion for producing the motion of the
horizontal shaft c.
Fig. 10. 11. 12 and 13 show plan and side views of various alternative construc-
tions of the shuttles and bobbins.
Fig. 14 is an enlarged plan view of the shuttle box and shuttle.
Figs. 15 and 16 are detail views.
The construction of the machine is, referring to the drawings, as follows:-
The horizontal or driving wheel shaft is not made in one piece as usual but is
composed of two parts a, c, which move independently of one another. The part a of
the shaft which has on its outer end the usual hand or driving wheel n, is carried at
one side in the bearing d, and at the other side in a sleeve b, in which it turns
freely. The other part c of the shaft is carried, at one end, in bearing g, and, at
the other end, it is fitted in and turns with the sleeve b, which latter is carried in
the bearing The sleeve may be pinned, at 6', to the part c of the shaft, as
indicated in dotted lines. The disc h, which is keyed on the end of the shaft C, has
on it a pin i, by means of which the needle bark is reciprocated up and down,
during the oscillations of the part c of the horizontal shaft. The needle bar k has
on it two guide pieces 1, 1, (see Fig. 24), which are so fitted, as shown, as to leave
groove or space m between them. The guide pieces are so cut or shaped, that
the groove or space m is of a wave-shape, as shown. Instead of having two
רנד

page_text: pieces 1.1, a single piece, with a wave-shaped groove m cut in it, may be used.
The peculiar conformation of the groove causes the pin i, at each forward and
backward swing of the shaft c and disc h to travel along it, and, in so doing, to
move the needle bark up and down twice. By this action, the needle is caused to
do two complete stitches for each turn of the hand or driving wheel. The increased
stitching speed is a great advantage.
Fitted on the needle bar k is a peg o, (see Fig. 1). This peg protrudes through
the slot p (see dotted lines Fig. 2), and also through a slot in the tension lever q.
The thread is led through the eyer of the lever g to the needle. A spiral springs,
which is attached to the lever, pulls up the thread after each stitch. On the
casing of the needle bar, is fitted the usual guide t, through which the thread passes
from the bobbin u, (see Fig. 4), to the disc tension v, and round this, through the
eye of the lever tension to the needle. The disc tension v consists of two
individual plates, 1, 2, (see Figs. 1 and 16). The outer plate 1 is loose on its
spindle 4 and may be adjusted, to suit the thickness of the thread, by the screw
nut x, which is fitted on the inner screwed end of the spindle. By screwing up
the nut in one direction, the plates 1, 2, will be held close together, whilst by
screwing said nut in the opposite direction, the plates will be left loose. In the
interior of the needle bar casing is a spring y', (see Figs. 2 and 16), which is
forked at its lower end, where it grips on an internally screwed saddle y³, fitted on
the spindle 4. The spring, acting on the saddle, tends to gently press it backwards,
and pull the spindle, so causing the plate 1 to press against the plate 2 of the
tension, to such an extent, that, whilst the thread can freely pass between the
plates, it is kept at the required tension. y³ is a spring arm, one end of which
passes backwards into and through the slot of the presser bar A, being secured
thereto by a screw '. The other end of the spring y bears against the spring y².
The presser bar A is forced down by the spiral spring a' (see dotted lines, Fig. 2),
and forced up again, after each stitch, by the rising of the feed plate B. The
spring 5 aids the action of the spring a¹, and also steadies the pin 6 inside said
spring. Every time the presser bar A is forced down, by the action of
the spring a', the spring y' is pressed in between the flat saddle piece r¹ and the
spring y', and forces it forwards, so as to interrupt the action of said spring y',
thereby, at such times, loosening the disc or plate 1 of the disc tension v, and
relieving the contact pressure between the plates 1, 2, so that the thread loses its
tension. This arrangement serves to stretch or loosen the thread, according to the
requirements of each stitch.
On the part a, (see Fig. 1), of the horizontal shaft, are two eccentric discs C, D.
The disc is loose, but the disc D is fixed to the shaft. Each eccentric or disc
has a tappet E and F. The tappet E is for the purpose of transferring motion
from the tappet F to the loose eccentric C, and this eccentric is regulated in its
forward and backward movements by the tappets.
The reason for having the eccentric C loose and actuated from the tappets, is
that the parts of the machine are so arranged, that the motions of the mechanism
actuated from the eccentric D, must always begin in advance of the motions of the
mechanism actuated from the eccentric C. To enable this to be always done, no
matter in which direction the driving wheel is turned, the eccentric D is fixed on
the driving shaft a and the loose eccentric is only actuated by the contact of the
tappets E. F. If the direction of revolution of the wheel n is at any time reversed,
the eccentric D will perform almost a complete revolution before the tappet F
strikes against the tappet E and actuates the eccentric C. The eccentric C
reciprocates the forked lever G, (see Figs. 6 and 7), and the latter, by suitable
connections on the bottom of the sewing table (see Fig. 5), actuates the feed plate B.
The movement of the feed plate is transmitted to the presser bar A. The
eccentric D, which is fixed to the shaft a, gives the forked lever H or eccentric rod,
a swinging or pendulous movement. The lever H is fulcrumed at P. By this
arrangement, not only the shuttle W, but also the needle bar k, and needle w, are
put into actiou, as hereinafter described.

page_text: The forked lever G has a slot I in it (see Fig. 6). A pin K is passed through
the slot and serves as a fulcrum for the lever. The pin is carried on a bracket L,
which protrudes outwards through a slot (not shown) in the casing M. The pin K
is free to slide up and down in the slot I. The bracket L can be raised or lowered
in the slot in the casing, and be clamped in any desired position, by means of the
screw N. By this arrangement, the length of the stitches can be easily adjusted,
as the raising or lowering of the bracket L circumscribes or extends the amount of
swing of the lower end of the forked lever G, and thereby makes the feed plate B
perform larger or smaller movements.
The lower end of the forked lever G reciprocates, through the intermediate
link o', the cam o. The cam o, at each movement of the lever G, presses against
and bears on the roller ', carried on a projection on the swing bar c¹, and causes
the said bar c' to partially turn or swing, in the direction of the arrow, in such a
manner as to reciprocate in one direction, the link B', which is attached, at one
end, to the arm on the bar c', and, at the other end, to the bar B2, attached to
the feed plate B, and, consequently, traverse the feed plate B, against the action of
spring d', and give it a feeding movement. The feed plate B is caused to move
backwards by the action of the spring d, which forces back the plate B, whenever
the cam o is so moved, by the action of lever G, as to permit the bar c' to swing
back, under pressure of the spring, to its original position.
The camo is wave-shaped or inclined on its under side, so that, when it is
reciprocated by the movements of the lever G, it so acts on the roller and bar c',
as to cause said bar to swing forward and back again, (under action of spring (¹),
twice for each reciprocation of the lever G.
The forked lever H is turnable on pin P as a centre. The pin P is carried in
the fixed bracket Q (see Fig. 8). The lower end H' of the forked lever H is
gripped by the fork of the cog sector R (see Fig. 5). The cog sector R meshes
with the cog pinion S. The reciprocation of the sector R turns backward and
forward the pinion S, and so oscillates the shuttle W in a circular path in the
shuttle box T (see Fig. 14). The forked lever H has also a peg on it (see
Figs. 1 and 8), which latter slides in the fork-shaped lower end of the cog sector Z
(see Figs. 1 and 9), and reciprocates the latter. The cog sector Z is turnable on
the pin u as a pivot. The sector Z meshes with the cog wheel e on the sleeve b.
The cog wheel e is secured by screws to the sleeve . As the sleeve b is connected
with the part o of the horizontal shaft, the latter, by means of the cog wheel e and
sector Z, is oscillated. The oscillations, as before described, by means of the
disch, cause the needle bar k to rise twice for each revolution of the hand wheel.
According to the thickness of the material being sewn, the shuttles are altered
in shape, but they are always so constructed, i.e., pointed at both ends, that at each
forward and backward movement, they produce a sewing loop. The bobbins for
the shuttles (Figs. 10 to 13) are ordinary wheel or cylinder bobbins.
The needle is threaded in the usual way,.and the tools &c. used with other
machines can, with equal facility, be used with this one.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. A sewing machine making two stitches for each complete revolution of the
driving wheel, constructed, arranged and operated, substantially as hereinbefore
described and as illustrated by the accompanying drawings.
2. In a sewing machine, an oscillating shuttle (W), pointed at each end so as to
produce a stitch during its forward movement and another stitch during its backward
movement, in combination with a needle bar, making a complete reciprocation, for
each movement of the shuttle so that two stitches are produced for each revolution
of the driving wheel, substantially as hereinbefore described with reference to the
accompanying drawings.
3. In sewing machines, a horizontal driving shaft, made in two parts a, c, which

page_text: act independently of each other, the part c having on it a sleeve, in which one end
of the part a revolves, substantially as hereinbefore described and shown on the
drawings annexed.
4. The combination with the shaft a, of the fixed eccentric D and loose
eccentric C, and the tappets E and F, substantially as and for the purpose herein-
before set forth.
5. The combination of the oscillating forked-lever G, cam o, swing lever c',
spring d, and intermediate levers for the purpose of actuating the feed plate B,
substantially as hereinbefore described and shown on the annexed drawings.
6. The combination of the oscillating forked lever H, toothed sector R, and
pinion S connected with the shuttle W, for the purpose of giving said shuttle
reciprocatory movement in a circular path, substantially as hereinbefore described
with reference to the drawings annexed.
7. The combination of the oscillating forked-lever H, pin V fitted in said lever,
toothed sector Z and ccg wheel e attached to the sleeve of the shaft c, for the
purpose of giving an oscillatory motion to said shaft c, substantially as hereinbefore
described and shown on the drawings annexed.
i
8. The combination with the oscillating shaft c, of the disc h fixed thereto, peg
on said disc, and wave-shaped groove m (in which said peg works), made in the
part of the needle bar, for the purpose of causing the needle bar to rise and fall
twice during each revolution of the driving wheel, substantially as hereinbefore
described and shown on the drawings annexed.
9. The tension device, consisting of the lever 7, spiral springs, pin o, discs or
plates 1, 2, forming tension v, screw a, springs y₁ and y³, and the saddle y², sub-
stantially as herein before described and shown on the drawings annexed.
Dated this 21st day of May 1892.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.