Improvements in Lockstitch Shuttle Sewing Machines.
Year: 1898

page_text: Date of Application, 7th Mar., 1898--Accepted, 80th Apr., 1898
COMPLETE SPECIFICATION.
Improvements in Lockstitch Shuttle Sewing Machines.
We, PERCY HUGHES HEWITT, (Barrister-at-Law), of Oakley House, Spring
Grove, Isleworth, London, W., and EDWIN ALLEN COCKLE, (Bootmaker), and
CHARLES MATTHEWS, (Bootmaker), both of 34, Victor Terrace, Harrow Road,
Willesden, London, N.W., do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to shuttle sewing machines and consists essentially in an
improved construction of shuttle whereby it is adapted to contain an ordinary
commercial bobbin or reel of thread so as to avoid certain well known disadvan-
tages incidental to the use of a special spool of small capacity such as is generally
employed; these disadvantages including not only greater complication and
consequent enhanced cost of the machine due to the necessity of providing special
mechanism for winding the spools, but also loss of time due to the necessity of
frequently stopping, removing, and accurately replacing the work, and of winding
thread from the ordinary reel on to the special spool, such loss bearing a high ratio
to the total time worked.
The invention will be described with reference to the accompanying drawings
forming part of this specification wherein Figure 1 is a longitudinal section on
the plane of division between the upper and lower halves of the shuttle. Figure 1*
is an inverted plan of the point end of the upper half of the shuttle. Figure 2
is a longitudinal sectional elevation on line 2-2 Figure 3 looking from the side
next the shuttle race the internal fittings being shewn in elevation. Figure 3
is a top plan of the upper half of the shuttle. Figure 4 is a rear end elevation of
the shuttle. Figure 5 is a cross section on line 5-5 Figure 3. Figure 6 is a
front end elevation of the bracket in which the spring centre for the reel is
mounted. Figure 7 is an elevation of the shuttle carrier or driver and its guide bar.
Figure 8 is a plan of the same and Figure 9 is an end view shewing the shuttle
driver guide bar and shuttle race in section. Figures 1 to 6 are drawn to an
enlarged scale.
The shuttle (A) as shewn in Figures 1 to 6 may conveniently be formed of metal
stampings and is of the same general configuration as other sewing machine shuttles
except that instead of being of D-form in cross-section and open at the flat side it
is of nearly circular cross-section the flattened side (a), (which works as usual
against the shuttle race so as to pass to and fro across the needle groove) being
closed and made of a width only sufficient to retain the shuttle in proper working
position in the shuttle driver or cradle. The flattened side (a) of the shuttle is
closed so that no accidentally loosened thread can escape from the shuttle and
there is no liability of the needle point catching in the shuttle. The shuttle is
made of separable halves (a', a²) the joint being preferably in the horizontal axial
plane 1-1 (Figures 2, 4, 5, and 6) of the shuttle, in order to permit of the intro-
duction of the reel (R) by the removal of the upper half (a¹). The reel turns upon
and between coned centres (B, C) mounted in the lower half (a) of the shuttle.
The back centre (B) is fixed to or stamped up from a plate (b) which is permanently

page_text: attached by rivets or otherwise to the inside of the upwardly turned flange (a³)
at the heel end of the lower half of the shuttle. The line of division between the
halves of the shuttle does not pass through the plate (b) which plate extends up
into the upper half of the shuttle and is adapted to be engaged with the down-
wardly turned flange (a) at the heel end of the upper half of the shuttle. For
this purpose the plate (b) is provided with one or more rearwardly projecting
studs (6) which enter corresponding holes in the flange (a) the union of the upper
and lower halves being completed by means of a spring latch (D) contained within
the point end of the shuttle. This latch is formed by a spring (D) fixed within
the lower half of the shuttle as shewn in Figures 1 and 2 and is provided with a
nib or nose (d) which projects into the upper half of the shuttle and is adapted to
snap into engagement with a catch plate (d) fixed within the upper half, so that
by inserting the studs (6) in their holes at the heel end of the shuttle, the connec-
tion between the two parts of the shuttle may be completed by pressing the catch
plate (¹) into engagement with the spring (D) the spring being of such form as
to exert a forward pressure against the catch plate and thereby maintain the secure
engagement of the studs (61) with the holes in the flange (a). The engaging
surfaces of the catch plate (d) and nib (d) are moreover so bevelled that the spring
will tend to hold the halves of the shuttle in close connection at the point of the
shuttle. The disengagement of the halves of the shuttle may be effected by sliding
the upper half (a) rearwards upon the lower half (thus overcoming the forward
stress of the spring (D) until the studs (6¹) are disengaged from their holes) where-
upon the bevelling of the surfaces of the catch plate (d) and nib (d) will cause
the spring to still further yield so as to permit of the halves of the shuttle being
completely separated by means of a direct pull away from each other. In order to
ensure coincidence between the meeting edges of the upper and lower halves at the
point of the shuttle, a steady pin (e) may be fixed in the catch plate so as to engage
in a longitudinal slot (el) in a plate (E¹) which may form part of a bracket (E),
(hereafter described), fixed in the lower half of the shuttle and having a second
slot (e) through which the spring (D) projects and by which the forward motion
of the spring is so limited as to ensure its maintenance when free in correct position
for engagement with the catch plate (d').
The forward coned centre (C) for the reel (R) is carried by a sleeve (c) fitted to
slide upon a spindle (F) fixed in the bracket (E) above referred to, the sleeve being
free to slide longitudinally upon the spindle but prevented from turning upon it
by a cross pin (f) fixed in the spindle and playing in a longitudinal slot (f) in
the sleeve, the pin and slot connection also serving to retain the sleeve upon the
spindle when the reel is removed. The cone (C) is formed in one with a disc (C¹)
between which and an abutment formed by a pair of lock nuts (G) screwing upon
the spindle F is confined a spiral spring (H) so as by its pressure against the
disc (C) to retain the reel (R) securely in position to rotate upon and between
the cones (B, C) as centres, with sufficient friction to check the rotation of the
reel so far as may be necessary to prevent more than the requisite length of thread
becoming unwound, the said friction also serving to impart tension to the thread.
The range of elasticity of the spring (H) and the length of the guide spindle (F)
and slot (f) are such as to permit of the reel being sprung into and out of position
in the shuttle as well as to enable reels of various lengths, less than that of the
full sized reel shewn, to be mounted between the centres (B) and (C) whilst
the adjustment of the stress of the spring (H) obtainable by means of the lock
nuts (G) enables the initial tension to be regulated and to be maintained constant
notwithstanding that reels of different lengths are used.
The bracket (E) is permanently fixed by rivets (e³) or otherwise in the lower
half (a) of the shuttle. It comprises a boss (e) in which the rear end of the
spindle (F) is permanently fixed, and an annulus or diaphragm (5) the two being
united by an intermediate portion affording a convenient means of attachment
to the flat side of the shuttle as shewn. The ring (5) being adapted to fit the
internal configuration of the upper and lower halves of the shuttle serves as a

page_text: means of ensuring coincidence of the meeting edges of the upper and lower halves
of the shuttle towards the point. The internal diameter of the ring (es) is such
as to just give passage to the disc (C) which is provided with a rearwardly extend-
ing peripheral flange (C²) working freely through the aperture of the ring, the
ring in conjunction with the flange serving to prevent any loose thread which may
accidentally become unwound from the reel from becoming entangled with the
spring (H), the depth of the flange (C2) being sufficient to ensure this result, not-
withstanding that the disc (C) may project considerably from the ring, as would
be the case when a short reel is being used.
Within the upper half (a) of the shuttle is mounted a thread guide (2) through
which the thread runs from whatever part of the reel the thread may be drawn,
this thread guide being placed in the corner space formed by the meeting of the
flat side (a) of the shuttle with the adjacent tangential portion (a) connecting
the flat and circular portions of the upper half of the shuttle. Near the top of
the upper part of the shuttle is a thread guide hole (j) through which the thread
passes from the thread guide () and which is partially covered by a spring tension
and guide plate (k) fixed by a screw (¹) by means whereof the nip of the thread
between the shuttle and the plate (k) may be varied for the purpose of adjusting
the tension of the thread. The plate () is provided with a stud (2) on its under-
side, this stud entering a hole in the top of the shuttle and serving as a guide stop
limiting the play of the thread beneath the plate (k) during the forward motion
of the shuttle. A similar guide stop for the thread during the rearward motion of
the shuttle is formed by the forward end of the plate () being curved downwardly
and upwardly as shewn at (7) in Figure 2, and housed in an aperture (¹) in the shell
of the shuttle. The form thus given to the forward end of the tension plate (k)
whilst offering no obstruction to the passage of the shuttle through the needle thread
loop, admits of the thread being easily passed beneath that end of the tension plate
during the operation of threading the shuttle as hereinafter described.
In order to prevent any possibility of the shuttle thread becoming caught under
the rear end of the tension plate (k) the rear portion of said plate is curved some-
what towards the flat side of the shuttle as shewn in Figure 3 and its extremity (12)
is bent downwards so as to lie snugly against the body of the shuttle as shewn in
Figure 2.
The operation of threading the shuttle, which may be very readily performed,
is as follows: The reel having been placed in position on the coned centres (B, C)
so that the thread in unwinding will cause the reel to rotate towards the left hand
(looking from heel to point of the shuttle) the end of the thread is passed through
the thread guide (i) and hole (j) in the upper (and thus far detached) half of the
shuttle and is then pulled round so as to pass under the forward end (7) of the tension
plate () and finally emerge from under said plate at the side opposite to that at
which the hole (j) is situate. The thread (M) having now assumed a position
(relatively to the upper half of the shuttle) substantially as indicated in Figures 3
and 5, the upper half of the shuttle may be placed upon and locked in engagement
with the lower half as already described. The spindle is then ready to be placed
in the machine.
It will be obvious that the halves of the shuttle may be held together by other
means than those hereinbefore described as for instance by a hinge (flush with
the outside of the shuttle) situated at the meeting edges in the flat side (a) of the
shuttle and a spring catch or catches at the opposite side.
The shuttle driver (N) is of the ordinary construction being provided with
horns (n) which embrace the pointed end of the shuttle and drive it on its return
motion, the horns being adapted to give passage to the loop of needle thread
through which the shuttle passes on its forward motion in the ordinary way. It
is also provided with a two-horned ledge (') on which the shuttle rests and with a
horn (2) which engages with the heel end of the shuttle so as to impart thereto
its forward motion. The shuttle driver holds the flat side of the shuttle in contact
with the shuttle race (0) and is mounted to slide along a guide bar (P) upon which

page_text: it is reciprocated by connection through a link (Q) with suitable driving mechanism.
The needle and shuttle driving mechanisms may be of any ordinary kind used
for shuttle sewing machines, the only alteration needed being such a proportioning
of the dimensions as to increase the stroke of the shuttle driver to the extent
rendered necessary by the increased length of the shuttle; to increase the stroke
of the needle bar to the extent necessary to enable the shuttle to engage with, and
pass through, the loop of the needle thread; and to increase the range of the
take-up" sufficiently to enable it to take up the slack of the needle thread loop
after the shuttle has passed through the loop in the formation of each stitch, all
these alterations being merely a matter of calculation not necessarily involving
any change in the design or operation of the machine.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:
-
1. A sewing machine shuttle adapted to contain an ordinary reel of thread and
constructed of a nearly cylindrical body portion pointed at the front end and
flattened at one side as specified and composed of halves separable at the longitudinal
central plane of the shuttle in combination with means of locking the halves in
engagement with one another to form a complete shuttle, substantially as specified.
2. A sewing machine shuttle adapted to contain an ordinary reel of thread and
constructed of a nearly cylindrical body portion pointed at the front end
and flattened at one side as specified and composed of halves separable at the
longitudinal central plane of the shuttle in combination with means of locking
the halves in engagement with one another, said means consisting of longitudinally
extending studs in the heel end of one half engaging with holes in the heel end
of the other half, and a spring catch at the point end of one half adapted to snap
into engagement with a catch plate at the point end of the other half and thereby
to hold the studs in engagement with their holes and to draw the halves of the
shuttle together at the point, substantially as described.
3. A sewing machine shuttle adapted to contain an ordinary reel of thread and
constructed of a nearly cylindrical body portion pointed at the front end
and flattened at one side as specified and composed of halves separable at the
longitudinal central plane of the shuttle, in combination with means of locking
the halves in engagement with one another substantially as described and with
coned centres for the reel to rotate upon, the rear centre being a fixture upon the
heel plate of the one half of the shuttle and the forward centre being fitted to slide
but prevented from turning upon a guide rod fixed longitudinally in the forepart
of the said half of the shuttle, and with a spring, confined between the last men-
tioned coned centre and an abutment, whereby the coned centre is pressed into
engagement with the bore of the reel, substantially as specified.
4. A sewing machine shuttle adapted to contain an ordinary reel of thread and
constructed of a nearly cylindrical body portion pointed at the front end
and flattened at one side as specified and composed of halves separable at the
longitudinal central plane of the shuttle in combination with means of locking
the halves in engagement with one another substantially as described and with
coned centres for the reel to rotate upon, the rear centre being a fixture upon the
heel plate of the one half of the shuttle and the forward centre being fitted to slide
but prevented from turning upon a guide rod fixed longitudinally in the forepart
of the said half of the shuttle, and with a spring confined between the last
mentioned coned centre and an abutment adjustable by screwing upon said guide
rod in order to enable the tension of the spring to be regulated and maintained
constant notwithstanding that reels of different lengths are used substantially
as described.
5. In a sewing machine shuttle adapted to receive an ordinary reel of thread
and constructed of halves divided longitudinally in the central plane of the shuttle
and locked together substantially as specified and provided with fixed and spring

page_text: pressed coned centres, the combination with the spring pressed coned centre, of
a cylindrically flanged disc and of a surrounding stationary annulus or diaphragm
apertured to give passage to the disc and serving to prevent entanglement of any
loose thread with the spring behind the disc substantially as specified.
Dated this 7th day of March 1898.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.