Improvements in Sewing Machines.
Year: 1891

page_text: Date of Application, 9th Dec., 1891-Accepted, 19th Mar., 1892
COMPLETE SPECIFICATION.
Improvements in Sewing Machines.
I, VICTOR LECONTE (père) of 37 Rue Sedaine, Paris, in the Republic of
France Sewing Machine Manufacturer, do hereby declare the nature of the said
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement, reference being had
to the accompanying four sheets of drawings and to the letters and figures marked:
thereon, that is to say :-
In the manufacture of heavy goods, such as water tight vessels, travelling equip-
ments, tents, and other articles made of canvas, or other woven material, whether.
coated with water proofing material or not, the two-needle sewing machines here-
tofore employed, having the spools below the table or work-plate, cannot feed the,
material forward at the first stroke of the needles, and in order to effect this
feeding forward it is necessary to commence the sewing on an additional piece of
material of any kind in which the needles make one or more stitches before com-
mencing on the pieces of material intended to be connected together; and when
this additional piece is removed in order to finish off the hem or other sewing, the
first stitches of such sewing have to be destroyed which causes a speedy deteriora-
tion of this part of the article by reason of the entrance of water, rain, etcetera,
through the imperfectly connected parts.
In order to obviate this inconvenience which is not only prejudicial to the manu-
facture but also to the preservation of the goods when made, I employ a feed-claw.
which obviates the necessity for the use of the additional or starting piece above
mentioned and avoids the false stitches necessitated thereby and consequently the
destruction of the first stitches of the work done. i.
:
Along with this important application of the feed claw to this special kind of
sewing machine for heavy work, the invention: comprises other improvements and,.
additions which form together a novel machine. One of these improvements relates"
to the feed presser which, in combination with the feed claw, prevents slack sewing..
which frequently occurs in sewing done by the ordinary machines. Another
improvement relates to means of producing the necessary tension of the threads
which prevents the re-twisting and consequently whirling between the thread feeder,
and the needle:..
To the head of the machine is fitted a separating plate which isolates the two
threads from one another and keeps them apart until they reach their respective
needles. The spools below the table or work plate, which furnish the under
threads for locking the upper or needle threads, are of comparatively small
diameter so as to decrease the length of the loop, thereby avoiding wear of the
thread in the eye of the needle and allowing of the use of comparatively small
needles, the result of which is that the holes made in the material by the needles
are only just sufficiently large to suit the size of the thread without leaving
openings which are not filled by such thread as is the case with the ordinary
machines, the needles of which are necessarily larger than is actually required by
the thread in. order to avoid excessive resistance to the passage of the latter
through the eye. A brake arrangement is also employed which prevents the too
free movement of the feed wheel and enables the machine to be driven by
hand without fear of any derangement whatever in the feeding forward of the
material.
A
To the above mentioned principal arrangements are added certain others which
conduce to the efficient working and regulation of the machine, and these will be
described hereafter in reference to the annexed drawings in which

page_text: Figure 1 is a frout elevation of a sewing machine constructed in accordance with
my invention, Figure 2 is a side view, and Figure 3 a plan of same.
Figure 4 is a detail view of the arrangement employed for regulating the tension
of the springs of the feeder and presser-foot.
Figures 5 and 6 are detail views (elevation and plan respectively) of the feed-
claw carrier and of the parts for giving motion thereto.
Figure 7 is a detail view of the ratchet and pawl arrangement which actuates
the feed.
Figure 8 shows an elevation and plan of devices for supporting the needles in
order to avoid bending or breaking the same.
Figures 9 and 10 show, in elevation and plan respectively, the double rack-
actuating device by means of which the requisite movements are imparted to the
spool hooks.
Figures 11, 12, 13 and 14, which are drawn to a larger scale than Figures 1 to 10,
relate to the spool and its hook, Figure 11 being an elevation shewing the hook in
the position corresponding to the formation of the stitch, Figure 12 a
plan of the
hock and of the support with the spool removed, Figure 13 a section of the spool
case with the spool in place, and Figure 14 an elevation of the support.
The table or bedplate a of the machine is carried on two side frames a' a' stayed
together in any suitable way and adapted to carry a crank-shaft and the pedals for
working the machine by the foot. On the table a is placed the support or arm b
terminated in front by the ordinary head which contains and guides the spindle or
needle carrier C, the spindle or stem D° of the presser-foot q' and the spindle or
steme of the presser el of the feeder.
The spindle or needle carrier c carries at its lower end the needle holder c¹ which
is easily removed to allow of the substitution, when necessary, of another needle-
holder of different pitch. This needle holder consists of a circular plate c¹
(Figure 16) provided with a central boss c. At variable distances apart, according
to circumstances, are formed in the plate c¹ two holes cc to receive the two
needles; the screws cc hold the needles in place, and other screws
the needle holder c¹ on to the spindle or needle-carrier c which is connected with
the lever d, oscillating on the fulcrum pin d¹ fixed on the support or arm b; the
other end of the lever d is in gear with the cam & on the driving shaft o.
c secure
This shaft o is the cam-shaft of the machine; it carries at the end opposite to
the driving pulley of a crank f' which gives motion to the double rack lever f
which imparts the requisite alternating rotary motions to the spool hooks, see
Figures 9 and 10. The lever f oscillates on an axis f' fixed to the frame. The
shaft o also communicates to the feed claw g, by means of the cam g', its complex
upward and downward and horizontal to and fro movements by which the said claw
effects the feeding forward of the material.
The feed claw g is mounted in a socket of the claw-carrier or shoe 4 which latter
is in the form of a tie which bears by the part ¹ on the cam g', being pressed
thereto by the spring i. The feed claw carrier is guided at one end in a hole
of the side rib of the table a. On the other hand, the feed-claw g, being fitted
between the guard plates j, is secure from lateral derangement.
The spring i is stretched between the point of attachment 3 on the claw carrier
or shoe and the arm of a bell-crank lever k k fixed to the shaft which regulates
the length of the stitch. The side k forms an abutment for a finger belonging
to the shoe. As usual the shaft is turned on its centre by means of a screw "
with a milled head; the point of this screw comes against a lever arm fixed on
the said shaft l. By turning the screw in one direction or the other, the horizontal
backward movement of the feed claw 9, and consequently the length of the stitches,
can be varied as may be required, see Figures 5 and 6.
The feed claw g effects the feed forward of the material, and as it comes into
action at the first stroke of the needles it obviously dispenses with the employment
of the usual additional starting piece of material. The action of this feed-claw is
rendered certain by the feed wheel m placed in front of it on a shaft m³ parallel to

page_text: the cam shaft o and connected to the latter by means of the pawl m², cam m³ and
ratchet wheel m* (see Figure 7). The stroke of the pawl m² may be adjusted by
the stop screw m³. A retaining pawl me prevents the ratchet wheel m* from
turning backwards and serves as a brake to prevent the too free movement of the
feed wheel m when the machine is operated by hand, by passing over and rubbing
on the teeth of the ratchet wheel m*. An ordinary wooden brake is arranged for
the same purpose on the shaft m' when the machine is driven by power. This
brake is not shown in the drawing.
Over the feed wheel m is placed the presser wheel e which bears upon the
material which is being sewn, with the whole force of a spring surrounding its
spindle and compressed between an adjustable collar n' and the end of a lever p
(Figure 4). This lever p turns on a fulcrum p' fixed in the support or arm b and
is acted on by a screw p' screwed into a socket fixed behind the head of the
machine. The object of this arrangement is to obviate the alteration of the position
of the collar n' when it is required to increase or decrease the tension of the spring n,
for in order to modify the action of the said spring it is only necessary to turn the
screw p³ to the right or left. A similar arrangement is employed for varying the
tension of the spring 9 of the presser-foot is the lever which presses on
the spring 9 by the action of the screw ³.
The spool hook, which has the requisite alternating rotary motion imparted to it
by the rack above mentioned, is composed (see Figures 11, 12, 13 and 14) firstly,
of the hook, properly so-called, C, which seizes the upper or needle thread F for
the purpose of opening the same out into a loop and passing the spool B through
the said loop; secondly, of the tail D which is a continuation of the body of the
hook and has for object to support the thread always at a uniform height corre-
sponding to the underside of the spool case B, thirdly, of the retaining notch E
which is placed at the bottom of the hook and forms a natural resting place for
the thread F coming from the said hook and going to the tail D as shown clearly
in Figure 11, and fourthly, of the arm G which serves to fix the hook to the
hollow axis H. This latter turns easily but steadily on the spindle K which
supports the plate P of the spool, which plate is formed with three external and
concentric projections P¹, and in plan with three projections Q constituting the
three points of contact with the spool case M. The spool case M carries on its
axis M' the spool B the lower face of which turns on a piece of oiled cloth N
which produces tension in the thread by the adhesion of the spool to the
said cloth.
Taking the needle A at the bottom of its stroke, as in Figure 11, it will be
understood that its thread F, taken by the hook C, held in the notch E, and
guided by the tail D at the height of the bottom of the spool case, cannot, in any
case, fall from the hook and create an obstacle to its passage under the spool at the
moment the needle rises, however bad the quality of such thread may be, or how-
ever much it may be twisted.
The thread
in the spool case.
The upper or needle threads FF on leaving their bobbins (Figures 2 and 3)
pass through holes formed in the heads of the tension devices s,s and are then
wound one or more times round the said tension devices (Figures 2, 3 and 15).
These consist of smooth cylindrical rods which can be turned round in their
bearings tt according to the degree of tension required, and stopped in these
bearings in any required position by the action of the friction spring arranged
inside such bearings. From the tension devices ss the threads pass through the
eyelets u of the thread guide fixed to the head of the machine, then they are
taken to the thread feeder v passing over friction rollers carried thereby, they then
separate and pass through the openings ¹² in a plate a fixed on the front of the
head, they then pass through the eyelets of a last guide y, then through the holes
in the needle holder c' and finally through the eyes of the needles. The thread
feeder is of the ordinary construction and acts in the usual way that is to say, it
from the spool passes in the ordinary way through the holes M²

page_text: descends to deliver the thread, and rises when the needles rise, oscillating for these
purposes on a fulcrum pin passing through its lower end. A single friction roller
may be employed in the head of this thread feeder, but I prefer to employ two,
one for each thread. The above described new tension arrangement avoids the
retwisting of the thread and consequently the whirling thereof between the thread
feeder, the guide y, the needle holder c¹ and the eyes of the needles. Another con-
sequence of this prevention of the whirling is to avoid the lifting or tapping of
the spools against the underside of their covering plates; on the other hand the
tension being definite and uniform the thread is in no way fatigued.
1
Figure 8 shows that the needles slide, below the guard plates j, in vertical
grooves, then pass through holes in two small plates before looping their
threads to receive the respective under threads delivered from the spools BB.
This arrangement prevents the needles from being bent or broken by an excessive
tension of the threads, because the needles are supported by the guides j³j*.
The action of the machine is as follows:
Supposing that it is required to sew together two breadths of material for a
watertight vessel for example, the ends of the two breadths are placed one over
the other immediately under the needles and the machine is set in motion. The
first stroke of the needles makes a stitch in the breadths of material and the
operation of the feed claw effects the feeding forward for the next stitch. This
feeding forward is afterwards sustained and aided by the toothed, roughened, or in
some cases smooth, wheels m e¹, and as the pressure of the wheel e¹ on the material
can be easily regulated, no slack stitching will be produced, and the two breadths
are fed forward quite equally.
As above stated, the spools for the under-threads are small in diameter as con-
pared with the spools heretofore employed, that the tension of the threads is very
smooth, that whirling is obviated, and that the tension has no effect on the needles.
The result is that I am enabled to use relatively small needles, consequently the
holes made by them in the material are comparatively small and are well filled with
thread and as additional or starting pieces of material are dispensed with, the first
stitches are not unsewn and the hem or other sewing produced has not the defects
of work which is begun by sewing on to additional or starting pieces.
Although the improvements forming the subject of my invention have been
described above in connection with a sewing machine having two needles and
intended for heavy work, I desire to have it understood that I do not limit myself
to the application of my improvements to such machines, but that I claim the
said improvements in connection with any kind of sewing machine to which they,
or either of them, may be applicable.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :―
First The use of a feeding claw g the stroke of which is adjustable by the
stitch-regulating device, as herein before described, and illustrated in Figure 5 of
the drawings.
Second-The feeding device consisting of a feed-wheel m and an elastically-
acting presser wheel e¹, the said feed wheel m being actuated by means of a ratchet
wheel and pawl as hereinbefore described, and illustrated in Figures 1 and 7 of the
drawings.
Third The feeding claw 9 and the feeding device forming the subject of the
second claiming clause hereof, combined, arranged, and operating together as herein-
before described, and illustrated in Figures 1, 2 and 3 of the drawings.
Fourth The use of levers and pressure screws for regulating by hand the
tensions of the springs of the presser-foot and of the feed-presser wheel, arranged
and operating as hereinbefore described, and illustrated in Figure 4 of the drawings.
Fifth The thread-tension devices constructed and operating as hereinbefore
described, and illustrated in Figures 2, 3 and 15 of the drawings.

page_text: Sixth The thread-feeder v provided with two independent friction rollers as
hereinbefore described, and illustrated in Figures 1 and 2 of the drawings.
Seventh-The thread-separating plate a constructed and arranged as herein-
before described, and illustrated in Figures 1, 2 and 3 of the drawings.
Eighth The needle holder constructed and applied as hereinbefore described,
and illustrated in Figures 1, 2, 11 and 16 of the drawings.
Ninth The spool hook Chaving a retaining notch E for the upper or needle
thread, and a tail or appendix D for supporting the said thread constantly at the
height necessary for its passage beneath the spool B, as hereinbefore described, and
illustrated in Figures 11 and 12 of the drawings.
Tenth The use of a piece of oiled cloth interposed between the spool B and
the bottom of the spool case M for the purpose of producing frictional resistance
to the turning of the spool in its case and thereby tension on the under thread, as
herein before described, and illustrated in Figure 13 of the drawings.
Eleventh The improved sewing machine constructed, arranged and operating
substantially as hereinbefore described, and illustrated in the drawings.
DL: och dess of Dacomber 1901
V. LECONTE (PÈRE),
Per W. H. Beck,
115, Cannon Street, London, Agent.
V. LECONTE (PÈRE),
Per W. H. Beck,
115, Cannon Street, London, Agent.