Improvements in Over-edge Sewing Machines.
Year: 1890

page_text: Date of Application, 21st Jan., 1890
Complete Specification Left. 20th Oct.. 1890-Accepted, 22nd Nov.. 1890
PROVISIONAL SPECIFICATION.
Improvements in Over-edge Sewing Machines.
We, WILLIAM ROBERTSON, and JAMES GUTHRIE ORCHAR, of Wallace Foundry,
Dundee, in the County of Forfar. North Britain, Engineers, WILLIAM ADIE, of the
same place, Draughtsman, and THOMAS ROBERTSON, of the same place, Foreman, do
hereby declare the nature of this invention to be as follows, that is to say :-
Our said invention relates to over-edge sewing machines of the kind described in
James Laing's Patent Specification No. 3493 of 1874, and working with a helical
needle and our present invention comprises improvements in various parts of the
machine these improvements being modifications of or additions to those for which
we have already applied for Letters Patent (No. 13167 of 1889).
One improvement consists in making the helical needle, which may be of generally
round, square, or other suitable section, with depressions or undulations which are
inclined to the needle instead of being transverse, , the drivers being made with counter-
part elevations or undulations. The depressions on the needle are by preference made
steeper on the sides on which the driver elevations bear than on the other side. This
construction gives an efficient driving action whilst allowing the needle to pass
through the cloth without injuring it. The grooves of the drivers may be made of
an undulating, square, or angular form in longitudinal section whether the needle is of
a round section or of a section similar to the groove, the needle in no case fitting
tightly between the sides of the groove.
Another part of the invention relates to the device at the front end of the thread
barrel by which the tension of the thread operates to regulate the backward move-
ment of the barrel. The spindle which extends through the thread barrel and at its
back end actuates the backward moving mechanism, has its front end in a bearing
within the barrel; and in front of this bearing there is fixed on the spindle end a
cone fitted within a concave conical bush which is itself fitted within the barrel in a
manner to admit of its moving a little longitudinally whilst it is made to turn with the
barrel by a pin screwed into it through a slot in the barrel. A spring is applied
tending to keep the bush just out of contact from the cone. The cone is made
with a spindle extending through the front end of the bush, and into the interior
of a cylindrical cup, which extends beyond the front end of the barrel, and on
which the coils of thread act as the stitches are about to be finally tightened in
the cloth. The cup fits quite loosely in the barrel at its front part but is at its
back end made with a rounded rim which fits the interior of the barrel whilst its
rotating with the barrel is ensured by a pin engaging it with the bush.
tension of the thread by inclining the cup. makes it push the bush inwards so as to
bear on the cone and turn the spindle.
The
For obtaining the backward movement of the thread barrel we have a pinion fixed
on the back end of the spindle which extends through the barrel. The pinion drives
gearing carried by a slide or carriage moving with the end of the spindle, such gearing
acting on a differential pulley or barrel and an endless cord, which differential device
may be arranged in various ways; or we cause the gearing to act on an endless chain
or on a toothed rack with a sufficiently reduced speed, provision being made by a
disengaging device or other suitable mechanism to allow of the barrel being moved
quickly forward again after each sewing operation. By another modification there is
fixed on the back end of the spindle a pinion made with inclined teeth like the threads
of a screw having several threads of quick pitch, this pinion gears with a long barrel or
spindle having screw threads suitable for gearing with the teeth of the pinion but
these threads are made of slightly different inclination, or the screw barrel is by
toothed wheels made to rotate at a slightly different speed, the effect of the difference

page_text: being to make the pinion on the spindle and the spindle with it to travel slowly back-
wards. The screw barrel is fitted to turn very easily and offers no great resistance
when the barrel is moved forwards again by hand.
When the pinion and rack arrangement is used the hand lever by means of which
the barrel is moved forward is arranged so as at the same time to move the pinion out
In a
of gear from the rack, the pinion then moving forward without rotating.
similar way when the screw barrel is used the hand lever may be arranged to move it
out of gear from the pinion when the latter moves forward.
In the gearing carried by the slide a ratchet wheel and spring pawl connection is
introduced at any convenient part to allow of the thread barrel being moved back for
the purpose of adjusting its position.
For the purpose of regulating the tension of the thread, frictional resistance is
applied to the barrel spindle by means of a strap the ends of which are drawn together
by a cord fixed to one end and passing over a pulley on the other end to a weight,
which can be varied to suit the tension required.
Dated this Pantinth day of Januarv 1800
EDMUND HUNT,
Applicants' Agent.
COMPLETE SPECIFICATION.
Improvements in Over-edge Sewing Machines.
We, WILLIAM ROBERTSON, and JAMES GUTHRIE ORCHAR, of Wallace Foundry,
Dundee, in the County of Forfar, North Britain, Engineers, WILLIAM ADIE, of the
same place, Draughtsman, and THOMAS ROBERTSON, of the same place, Foreman, 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, that is to say :-
Our said invention relates to over-edge sewing machines of the kind described in
James Laing's Patent Specification No. 3493 of 1874, and working with a helical
needle, and our present invention comprises improvements in various parts of the
machine, these improvements being modifications of or additions to those described in
our Patent Specification No. 13167 of 1889.
We hereunto append four sheets of explanatory drawings showing our improve-
ments, and to be hereinafter referred to in particularly describing the same.
Figures, 1, and 2, on Sheet, 1, are a plan and front elevation of the complete
machine as made with a modification of our improved details.
Figures, 3, and 4, on Sheet, 2, are enlarged sections as at right angles to each other,
showing our improved needle and one of its drivers.
Figures, 5, and 6, are sectional plans showing two modifications of our improved
device at the end of the thread barrel.
Figures, 7, 8, and 9, on Sheet, 3, are a plan a sectional end elevation and a front
elevation showing on an enlarged scale certain parts shown in Figures, 1,
and 2, and
Figures, 10, and 11, on Sheet, 4, represent modifications of the parts shown on
Sheet, 3.
In these drawings the same reference letters and numerals are used to mark the
same or like parts wherever they are repeated.
One of our present improvements consists in making the helical needle, N,
Figures, 3, and 4, which may be of generally round, square, or other suitable section,
with depressions or undulations which are inclined to the needle instead of being
transverse, and which by preference form parts of helical grooves of suitable number
and pitch, the drivers, D, being made with inclined counterpart elevations or undulations.
The depressions which are in the outer surface of the needle, N, are by preference
made steeper on the sides on which the driver elevations bear than on the other
sides. This construction gives an efficient driving action whilst allowing the needle
to pass through the cloth without injuring it. The grooves of the drivers, D, may be

page_text: made of an undulating, square, or angular form in longitudinal section, whether the
needle, N, is of a round section or of a section similar to the groove, the needle
in no case fitting tightly between the sides of the groove. The projecting parts
between the grooves of the drivers, D), are by preference rounded as shown in Figure, 3,
to avoid the risk of the needle catching on corners; and some elasticity is given to
the driving action by interposing a spring, S, between each driver and its actuating
pinion, P, as shown in Figures, 3, and 4. The upper front driver, D1, Figure, 2, is
held as described in our earlier Specification hereinbefore referred to, by a movable
bracket, D2, secured by a cross bar, D 3, and screw, D4; and we avail of the front
of the bracket, D2, as convenient for holding one leg, 21, of the presser foot plate, 22,
this leg being held in and pressed by a spring in a box, 23, fixed to the bracket and
adjustable by a screw, 24.
Another part of our present invention relates to the device at the front end of the
thread barrel, B, by which the tension of the thread operates to regulate the backward
movement of the barrel. In the modification shown in Figure, 5, the spindle, A, which
extends through the thread barrel, B, and at its back end actuates the backward
moving mechanism has its front end in a bearing, B1, within the barrel, B; and in
front of this bearing there is fixed on the spindle end a cone, A 1, fitted within a
concave conical bush, B 2, which is itself fitted within the barrel in a manner to admit
of its moving a little longitudinally whilst it is made to turn with the barrel by a
pin, B3, screwed into it through a slot in the barrel. A spring, B4, is applied
tending to keep the busb, B 2, just out of contact from the cone. A 1. The cone is
made with a spindle, A 2, extending through the front end of the bush, B2, and into
the interior of a cylindrical cup, C, which extends beyond the front end of the barrel, B,
and on which the coils of thread act as the stitches are about to be finally tightened
in the cloth. The cup, C, fits quite loosely in the barrel, P, at its front part
but is at its back end made with a rounded rim which fits the interior of
the barrel, whilst its rotating with the barrel is insured by a pin, 1, engaging it with
the bush, B 2. The tension of the thread by inclining the cup, C, makes it push the
bush, B 2, inwards so as to bear on the cone, A 1, and turn the spindle, A. The cup, C,
is secured to the spindle, A2, by a washer and screw nut, (2, but is fitted so as to be
capable of the inclination described. In the modification shown in Figure, 6, the
spring, B4, is arranged to act between the bearing, B 1, and the bush, B2, instead of
between the latter and the cone, A 1.
For obtaining the backward movement of the thread barrel, B, we have a
pinion, A 3, Figures, 1, 2, 7, 8 and 9 fixed on the back end of the spindle, A, which
extends through the barrel. The pinion, A 3, drives gearing carried by a slide or
carriage, E, moving on fixed guides, E1, E2, and connected by a collar to the
spindle, A, and barrel, B, so as to move therewith. The gearing may be arranged to
act on a differential pulley or barrel and an endless cord as shown and described
in our earlier Specification herein before referred to, or in any of the various equivalent
ways of which such differential endless-cord device is susceptible; we however
prefer the arrangement shown in Figures, 1, 2, 7, 8, and 9, in which a stationary
toothed rack, F, is employed. With the rack, ', there gears a pinion, G, on a short
spindle carried by the carriage, E, and which engages through a ratchet wheel and
pawl, 25, with a bevil wheel, G 1, gearing with a bevil pinion, G 2, in one piece with
or fixed to a spurwheel, G 3, having in gear with it the pinion, A 3, on the back
end of the barrel spindle, A. To assist in adjusting and controlling the backward
movement of the thread barrel, B, a friction strap, H, is applied to a boss on the
spindle, A, the ends of the strap being connected to a small lever, H 1, carrying a
weight, H 2, which is adjustable on the lever. When the thread barrel, B, has to be
moved forward again for a fresh seam, the pinion, G, is disengaged from the rack, F,
to allow the carriage, E, with the thread barrel, B, to be moved forward freely, the
disengagement being effected by slightly depressing the carriage, E, by means of
the handle, J, which is used for moving the parts forward. The part fitting and
sliding on the upper guide bar, E 1, is a block, J 1, connected by a link, J 2, to the
handle, J, which last is jointed by a pin, J 3, to the carriage, E. A spring, K, fixed

page_text: to the carriage, E, bears on the sliding block, J 1, and holds the carriage up with the
pinion, G, in gear with the rack, F; but when the handle, J, is turned a little to
the right it depresses the carriage the joint of the link, J 2, acting as the fulcrum.
The handle, J, is made with a heel projection, J 4, to act as a stop and limit the
extent of its movement. The ratchet wheel and pawl, 25, allow of the barrel
being moved back by hand if required at any time for the purpose of adjustment.
Figure, 10, on Sheet, 4, is a sectional side elevation of a modification of our
devices for moving back the thread barrel, B, in which an endless pitch chain, M, is
used. This chain, M, passes round a sprocket wheel, M 1, fixed to or in the same
piece with a bevil wheel, M 2, driven by the pinion, A 3, on the back end of the
barrel spindle, A; and the two parts of the chain also pass round two sprocket
wheels, M3, M4, carried at the back end of a frame bracket, M 5, and thence down to
and round a weighted pulley, M 6. The two sprocket wheels, M 3, M 4, are geared
together by spurwheels of slightly different sizes; and when the machine is sewing
the chain, M, is moved in the direction of the arrows the weighted pulley then
descending and drawing back the thread barrel in consequence of the differential
action of the wheels, M 3, M 4. The upper wheel, M 3, is movable by means of a
handle, M. 7; so as to disconnect the spurwheels of the two sprocket wheels, M 3, M4,
and to allow of the chain, M, being drawn forward along with the thread barrel, B.
By another modification shown in Figure, 11, on Sheet 4, there is fixed on the
back end of the barrel spindle, A, a pinion, Q. made with inclined teeth like the
threads of a screw having several threads of quick pitch, and this pinion gears with
a long barrel, Q1, having screw threads suitable for gearing with the teeth of the
pinion, Q, but these threads are made of slightly different inclination, or the screw
barrel, Q1, is by toothed wheels made to rotate at a slightly different speed, the effect
of the difference being to make the pinion, Q, on the spindle, A, and the spindle and
barrel, B, with it to travel slowly backwards. The screw barrel, Q1, is fitted to turn
very easily and offers no great resistance when the barrel is moved forward again by
hand. The pinion, Q, is made in two parts which can be screwed up more or less
close together to obtain the best gearing or meshing action with the barrel, Q 1.
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. The improved form of the helical needle and the corresponding parts of the
drivers the same being made with inclined depressions or undulations substantially as
and for the purposes herein before described.
2. The improved construction of the parts at the front end of the thread barrel,
substantially as herein before described, and as shown in Figures, 5, and 6, of the
accompanying drawings.
3. The improved combination of parts for obtaining and controlling the backward
movement of the thread barrel, and comprising a pinion gearing with a fixed rack and
means to move the pinion out of gear substantially as hereinbefore described and as
shown in Figures, 1, 2, 7, 8, and 9 of the accompanying drawings.
4. The modification of the backward movement device substantially as shown in
Figure, 10, of the accompanying drawings and hereinbefore described.
5. The modification of the backward movement device substantially as shown in
Figure, 11, of the accompanying drawings, and hereinbefore described.
Dated this Eighteenth day of October 1890.
EDMUND HUNT,
Applicants' Agent.