Improved Process and Machine for Sewing Hem Stitch.
Year: 1897

page_text: Date of Application, 31st Dec., 1897-Accepted, 14th May, 1898
COMPLETE SPECIFICATION.
Improved Process and Machine for Sewing Hem Stitch.
I, THOMAS RICHARD SHILLITO, of 89, Chancery Lane, London, W.C., Engineer, do
hereby declare the nature of this invention, a communication to me from abroad by
the Fabrik fur Spezialnah-maschinen A.G. (Patente Julius Gutmann) of Zurich,
Switzerland, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This invention relates to a process of and to a machine for sewing hem stitch of
the kind that would follow a line winding to and fro between two imaginary
parallel lines and in which machine the sewing is performed by means of a piercer
and needles, the piercer with the needles penetrating the fabric to be sewn, and the
needles forming stitches at the side of the piercer.
The invention has for object to provide, in such hem stitch sewing machines,
means by which the seam can be produced not only in the direction of a straight
line but in all directions and configurations, for which purpose the needles and
piercer as also the catcher or shuttle driving mechanism may be turned simul-
taneously from one direction to another.
The invention comprises an arrangement in hem stitch sewing machines of two
driving mechanisms connected with a common driving spindle, one of which
mechanisms is in connection with the rotatable and displaceable needle carrying
rod, upon which latter is located the rotatable and displaceable sleeve which carries
the piercer, and the other driving mechanism in connection with the rotatable sleeve
carrying the catcher or shuttle driving mechanism.
Hitherto only such hem stitch sewing machines have been known as will sew
such a seam in one direction and not allow of desired changes in the direction
thereof, whereas by means of this invention such changes are rendered practicable
by reason of the collective mechanisms for the production of the winding seam being
maintained in a certain prescribed position relatively to the central line of the
seam, as they are all adapted to turn simultaneously in the desired direction of the
seam to be sewn, to which end, the head on which the needle bearings are seated,
the piercer, the needle plate, and the catcher or shuttle seats are arranged to turn,
the mechanisms for operating the rotation of said parts being so connected, through
spindles and bevel wheels, with a single spindle, that the rotation of all these parts
may be operated therefrom simultaneously and in the same direction. The needle
clamps are arranged so as to be displaceable parallel to one another and the piercer
has a motion independent of the needles, in the line of its longitudinal axis,
therefore it is not compelled to take part in the whole downward movement of the
needles but may remain stationary while the needles move lower and again higher.
When the needles are rising above the fabric, the piercer may still remain in the
same, which thus has for a short interval a hold on the piercer seated in it.
In the accompanying drawings, Fig. 1 is a part sectional side view of a hem stitch
sewing machine constructed in accordance with this invention. Fig. 2 an end view
looking towards the machine head, the mechanisms which do not form part of the
invention being omitted with a view to greater clearness.
respectively an elevation and a sectional view of a needle head.
Figs. 34, 3, are
Fig. 4 is a diagram-

page_text: matic view of the stitches.
mechanism.
Figs. 5, 6, 7, are views relating to the shuttle driving
1 is the main spindle of the machine on which is fixed a bevel toothed wheel 2
which sets in rotation the spindle 4 carried in the plate 3 and this movement is
transmitted through the toothed wheel 5 on spindle 4 to the toothed wheel 6 and
to the cam 7 attached to this latter.
The cam 7 acts on the lever 8 which is mounted to oscillate on the machine frame
and has connected to the end of its shorter arm a slide bar 9 for which purpose said
end of the lever is fork shaped and has there fitted to it a bearing block 10 for the
reception of a pin 11 projecting from the slide bar, consequently this latter is
moved from the cam up and down at certain intervals of time.
is
12 is a fork attached
to the lower end of the slide bar 9 and holding suspended and so as to be capable of
turning therein the sleeve 13 which has transmitted to it the up and down movement
of said slide bar. On the sleeve 13 which turns on the sleeve 14 and is movable up and
down thereon is held a slide plate 15 over which the head 17, provided with the
needle seats or clamps 18, moves up and down. The sleeve 14 is firmly attached
to the machine head. The head 17 is connected to the rod 19 and moves with it
both in the turning movement taking place in the fixed sleeve 14 and in the up
and down movement, the latter movement being brought about in the usual manner
by a cam fixed on the spindle 1 as in the ordinary Singer machine. The move-
ment of the piercer 21 is independent of the rod 19. Said piercer
connected by means of a small plate 22 to the sleeve 23 placed
on the rod 19 upon which latter said sleeve is adapted to slide up and down and
therefore has a separate movement in this direction, but turns with it owing to
the engagement of a small lug on the rod in a slot of the sleeve. The up and down
movement of the sleeve 23 (Fig. 2) is occasioned by the slide 24 which is guided in
the machine head and is normally pressed downwards by a spring 25. The slide 24
is raised by means of a small bell crank lever 27 (Fig. 2) which takes underneath a
lug 26 projecting from said slide. The bell crank lever 27 is operated by an
eccentric 28 fixed on the spindle 1 and when said lever is thus caused to perform a
stroke, it lifts the slide 24, the sleeve 23 displaceable on rod 19, and the piercer 21,
and after the lever 27 has lifted the slide 24, the latter is pressed down by the
spring 25, therefore the rod 19 which moves the needle seats up and down is itself
moved up and down from the spindle 1, in but independent of the sleeve 23 and
turns with this latter in the sleeve 14 and the piercer is operated from the spindle 1
as before described.
30 is a sleeve mounted on the rod 19 near its upper end and so in connection there-
with that it turns with said rod but does not move up and down with it. On this
sleeve is fixed a bevel toothed wheel 31 which meshes with a similar wheel 33 fixed
on a spindle 32 mounted in the machine frame and carrying at its rear end the bevel
toothed wheel 34 meshing with the wheel 35 fixed on the upper end of the vertical
spindle 36.
39 is a horizontal spindle which is in connection with the vertical spindle 36
through bevel toothed wheels 37, 38, and is set in rotation from the crank handle 43
through bevel toothed wheels 40, 41, 42, the wheel 40 being fixed on, or in one piece
with, the crank spindle, and upon rotating this latter, the spindles 39, 36, 32, the
toothed wheels 31, the sleeve 30 carrying with it the rod 19, and the sleeve 23 on the
latter, or in other words, the piercer 21 and the head 17 furnished with seats or
clamps for carrying the needles, are rotated.
There is further on the spindle 39 a bevel toothed wheel 44 which, meshing with a
similar wheel 45, turns the sleeve 46 on which the latter wheel is fixed and on which
the mechanisms for operating the catcher or shuttle are arranged, said mechanisms
being turned from the crank handle 43 simultaneously with the mechanisms for
bringing about the movement of the needles and piercer.
The catcher or shuttle motion for forming the thread loops is obtained from the
spindle 1 through a crank motion whereby the lever 48 is caused to oscillate up and
down. This lever at its free end is formed with a fork 49 carrying a ring 51 in

page_text: which a sleeve 50 is so held as to be capable of turning therein and also of sliding
up and down on the sleeve 46 with which it rotates when the handle 43 is turned.
The sleeve 46 is fitted with a pin 52 which does not project beyond the cylindrical
surface of the same. On this pin is mounted a lever 54 provided with a toothed
segment 53. A slot in said sleeve allows the lever 54 to strike outwards and this
action is brought about by the up and down movement of the sleeve 50 when it
presses alternately against the upper and lower arms of the lever 54 and causes
this lever to swing. In this swinging movement the toothed segment turns, first in
one direction and then in the other, the small toothed wheels 55 fixed on spindles 57
of the shuttle driving mechanism whereby said mechanism is actuated (Figs. 5, 6),
consequently the shuttle motion is obtained from the spindle 1 through the lever 48
whereby the sleeve 50 is moved up and down on the sleeve 46, by which movement
the lever 54 with its toothed segment 53 is set in oscillation and the shuttles rotated.
The collective shuttle driving mechanisms up to the lever 48 take part in the
rotary movement of the sleeve 46. The needle plate is also connected with the
sleeve 46 and joins in the rotary movement. The head 17 for the needle seats or
clamps 18 consists of a part 60 having a groove for the reception and guidance of
said needle seats and of a part 61 screwed thereto in which the slide plate 15 is
guided (Fig 34). The needle seats or clamps 18 move to and fro in the groove of
the part 60. They are provided with small rollers 62 which take against a raised
surface 63 of the slide plate 15 but they allow the slide 22 which carries the piercer,
to slide untouched between them.
The movement of the needles is as follows:-The slide plate 15 guided in the
part 61 of the needle head is with its wedge shaped raised surface 63 so actuated, by
the lever 8 and cam 7, relatively to the rod 19 which has a regular up and down
movement, that at every third downward movement of the needle rod, the wedge
In this,
surface 63 passes at the point of its greatest width between the rollers 62.
the needle seats or clamps 18, which are connected to said rollers, are displaced
parallel to one another in the groove or slideway of the part 60 and then perform
their greatest outward stroke, the springs 64 then pressing them against the wedge
surface 63.
In the greatest outward stroke of the needles, the wedge surface 63 remains with
its widest part between the rollers 62 until the needles are withdrawn from the
fabric, that is, so long as the slide plate 15 and the rod 19 move up and down, and
then the needle seats return to their inward position. The piercer upon each
descent of the needles moves quite independently of these latter. The needles
engage in the piercer as shewn in. Figs. 3^, 3, yet the downward stroke of the
piercer is not the same as that of the needles, seeing that it remains in a raised
position after it has pierced the fabric, which permits the contact of the attach-
ment 65 with the needle plate, whilst the needles pass lower down, pass through
the fabric and form the stitch.
The stitches are formed by means of shuttles 58 in the known manner, said
shuttles being driven from the toothed segment 53 through the spindles 57 rotated
in the manner before described. The box 66 in which the mechanisms for driving
the shuttles and the needle plate are located is connected to the sleeve 46 and turns
therewith.
The machine works as follows:-The needles descend with and at the same time as
the piercer. The piercer pierces the fabric and then remains stationary whilst the
needles continue their downward movement and form a stitch. In two successive
stitches the needles descend within the piercer or within the range or boundary
thereof. In the next following or third stitch the needles descend with the piercer
as in the two previous stitches up to a certain point, but before entering the fabric
they perform a lateral outward stroke which takes them beyond the piercer and it
is at these points that they enter the fabric (Fig. 4). In this way the known hem
stitch is produced.
By dispensing with one of the needles a partial or one sided hem stitch is produced.
In sewing such a seam the crank handle 43 is turned according to the windings or

page_text: curves of the seam to be sewn. The sleeve 13 then turns with the slide plate 15,
the rod 19 with the needle head 17, the sleeve 23 with the piercer 21, and the
sleeve 46 with the shuttles and the needle plate, all regularly together.
Having now particularly described and ascertained the nature of said invention
and in what manner the same is to be performed, as communicated to me by my
foreign correspondents, I declare that what I claim is:-
:-
1. A process for the production of a hem stitch in all directions by means of a
machine, said process consisting in turning the piercer, the needles, the fabric
carrier, and the shuttles or catchers simultaneously and in the same direction so
that the formation of the hem stitch and the movement of the fabric takes place
in the direction corresponding to the turning movement, substantially as described
and shewn.
2. A hem stitch sewing machine for the performance of the process referred to
in Claim 1, in which machine, for the purpose of producing seams of any desired
curvature, the piercer, the needles, the fabric presser, and the shuttles or catchers are
located in parts adapted to be turned simultaneously from one point, substantially
as described and shewn.
3. In a hem stitch sewing machine of the kind referred to in Claim 2, the arrange-
ment of the operating mechanisms of the piercer and of the needles separate from
one another so that the piercer has not to take part in the whole of the downward
movement of the needles, substantially as described and shewn.
3. In a hem stitch sewing machine of the kind referred to in Claim 2, the arrange-
ment of the wedge for moving the needles away from one another for the purpose of
widening by the needles the hole formed in the fabric by the piercer after the
needles have passed down into the fabric, substantially as described and shewn.
Dated this 31st day of December 1897.
THOMAS R. SHILLITO,
89, Chancery Lane, London, W.C.