Year: 1896

page_text: Date of Application, 13th Apr., 1896
Complete Specification Left, 13th Jan., 1897-Accepted, 27th Mar., 1897
I WILLIAM HENRY DORMAN, of The Hawthorns, Newport Road, Stafford,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for its object improvements in sewing machines such as are
described in the Specification of former Letters Patent granted to me No. 23267,
A.D. 1892, and consists in imparting to such a shuttle as therein described a
continuous revolving movement of varying velocity. This movement is forward
in a circular path through the loops of thread drawn up above the surface of the
work by the needle but, in order to prevent twisting of the shuttle thread, instead
of allowing the shuttle to continue in its forward circular path I cause the shuttle
while still revolving to turn over backwards after passing through the loop until
it arrives in a position ready to pass through the next loop drawn up by the needle.
The revolving movement of the shuttle is not circular and the outer curved side of
the shuttle is always presented to the work being operated upon.
The invention also consists in providing a suitably operated finger which acts*
upon the shuttle thread so as to keep the same out of the way of the needle.
The shuttle works and is supported against a flat face and is driven-through
the loops of thread which the needle draws up above the work-by a suitable
shuttle carrier in which the shuttle is carried being retained by claws on the carrier
which receive the one the heel and the other the point of the shuttle. One of
these claws is capable of being opened for the purpose of removing or inserting the
shuttle.
The shuttle carrier is driven by a crank dise to which a revolving movement is
given by the machine and the carrier is provided with a slot which engages a die
mounted on a pivot. This pivot receives from the macbine a movement to and
from a position concentric with the crank disc. When the pivot is concentric with
the crank disc the shuttle moves in a forward circular path through the loop of
thread drawn up by the needle after which the withdrawal from and return of the
pivot to its position concentric with the crank disc together with the continued
revolution of the crank cause the shuttle to turn over backwards into a position
ready to pass through the next loop of thread drawn up by the needle.
In cases where a large thread and coarse stitches are employed the twisting of
the thread is of little consequence and may make the shuttle to revolve
continuously point forward in a circular path.
For the purpose of rotating the crank dise I employ suitable gear wheels and in
order that the crank disc may revolve at a varying velocity which is necessary
to suit the timing of other parts of the machine I interpose between it and the
main cam shaft of the machine suitable gearing such as elliptical wheels or I
employ a crank which engages a slot formed in a disc mounted on a shaft set
eccentrically to the crank shaft centre. This arrangement is so set and timed
as to cause the shuttle to move at increased velocity forward through the
needle thread loop and at diminished velocity when making its retrograde
movement.

page_text: The pivot carrying the die previously referred to is mounted in a slide which
is operated at the proper times by a suitable lever, and cam from the cam shaft
of the machine and a cam is also provided to give motion to the finger which
prevents the shuttle thread getting in the way of the needle.
Dated shi 11AL
Improvements in Lock-stitch Shuttle Sewing Machines.
I, WILLIAM HENRY DORMAN, of the Green Hall, Stafford, formerly of
The Hawthorns, Newport Road, Stafford, aforesaid, Engineer 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:-
This invention has for its object improvements in sewing machines such as áre
described in the Specification of former Letters Patent granted to me No. 23267,
A.D. 1892, in which specification a curved shuttle is described which is reciprocated
in a circular race forwards through the loop of thread drawn up by the needle and
backwards in the same race to a position ready to again move forward through the
next loop which the needle draws up.
This to and fro movement when the machine is run at considerable speed is
found to damage the cop of thread contained in the shuttle which when only
partially used up is sometimes found to be so ravelled or intertwined as to prevent
its withdrawal by the operation of the machine.
To obviate this objection and allow of increased speed of working I impart to
the shuttle, in place of the reciprocating movement; a continuous revolving move-
ment of varying velocity. This movement is forward in a circular path through
the loops of thread drawn up above the surface of the work by the needle but, in
order to prevent twisting of the shuttle thread, instead of allowing the shuttle to
continue in its forward circular path I cause the shuttle while still revolving, to
turn over backwards after passing through the loop until it arrives in a position
ready to pass through the next loop drawn up by the needle. The revolving
movement of the shuttle is not at all times circular and the outer curved side of the
shiittle is always presented to the work being operated upon.
The invention also consists in providing a suitably operated finger which acts
upon the shuttle thread so as to keep the same out of the way of the needle.
The shuttle works and is supported against a flat face and is driven-through
the loops of thread which the needle draws up above the work-by a suitable
shuttle carrier in which the shuttle is carried being retained by claws on the
carrier which receive the oùe the heel, and the other the point of the shuttle.
One of these claws is capable of being opened for the purpose of removing or
inserting the shuttlė.
The shuttle carrier is driven by a crank disc to which a revolving movement is
given by the machine and the carrier is provided with a slot which engages a dise
mounted on a pivot. This pivot receives from the machine a inovement to and
from a position concentric with the crank disc.. When the pivot is concentric with
the crank disc the shuttle moves in à forward circular path through the loop of
thread drawn up by the needle after which the withdrawal from and return of the
pitot to its position concentric with the crank disc together with the continued
revolution of the crank cause the shuttle to turn over backwards into a position
ready to pass through the next loop of thread drawn up by the needle.
In cases where a large thread and coarse stitches are employed the twisting of

page_text: the thread is of little consequence and I may make the shuttle to revolve
continuously point forward in a circular path.
For the purpose of rotating the rank dise I employ suitable gear wheels and in
order that the crank disn may revolve at a varying velocity which is necessary to
suit the timing of other parts of the machine interpose between it and the main
cam shaft of the machine suitable gearing such as elliptical wheels or I employ a
-crank which engages a slot formed in a disc mounted on a shaft set eccentrically to
the crank shaft centre. This arrangement is so set and timed as to cause the
shuttle to move at increased velocity forward through the needle thread loop and
at diminished velocity when making its retrograde movement.
The pivot carrying the die previously referred to is mounted in a slide which is
operated at the proper times by a suitable lever and cam from the cam shaft of the
machine and cams are also provided to give motion to the finger which prevents the
shuttle thread getting in the way of the needle.
My invention is illustrated in the accompanying drawings in which:
Fig. 1. is a front view shewing a portion of the machine.
Fig. 2. is a plan of the same.
Fig. 3. shews the crank pin and dise for imparting the variable movement to the
shuttle.
Fig. 4. is a side view parily in section shewing the shuttle and carrier and the
cam and connections which give the back turn over movement to the shuttle.
Fig. 5. is a front view shewing the shuttle and its carrier.
Fig. 6. shews the shuttle and carrier in four of the different positions they
assume..
Fig. 7. is a diagram shewing the method of imparting the variable movement to
the shuttle.
Figs. 8. 9 and 10 are views shewing the thread finger.
The machines resembles in its general features that described in the Specification
No. 23267 A.D. 1892 previously referred to but instead of the reciprocating move-
ment of the shuttle therein described I now make use of a continuous revolving
movement of varying velocity as follows:-
Upon the cam shaft a (see Figs. 1 and 2.) mount a gear wheel a' which gears
with a similar wheel a mounted on a stud a³. The wheel a² carries a crank pin a*
(see Fig. 3) upon which is a die a fitted to slide in a slot a formed in a disc a'
which is mounted on a shaft a" which shaft is set eccentrically but parallel to the
stad and the shaft a is free to revolve in the bearings a a
I
When the machine is in motion the cam shaft a revolves with uniform velocity
and imparts the same to the equal wheels a' and a² and to the crank pin a' and
die a but because the shaft a" is set out of centre with the stud as the disc a' is
driven by the pin a' and die a at a varying velocity being quicker when the die a
is nearer the centre x (see also Fig. 7) of the shaft as and slower when the die a' is
further from the centre a, which may be thus explained.
The dotted circle y (see Fig. 7) represents the pitch line of the wheel a' and the
dotted circle y' that of the wheel a² revolving as shewn by the arrows. The crank
pin a is carried round by the wheel a in a circle about the centre of the stud a³
and with it the die a' thus driving the disc a' but at a varying velocity because
while the crank pin at is moving through the equal angles
dise a' is moving through the unequal angles a
the disc a' being quicker than the crank a say from a to
crank say from a to x.
&c. the
&c. the movement of
ani slower than the
A roll may be used instead of the die a' and the slot « in the disc a' may be
curved instead of being straight or the crank and disc may be dispensed with and
a pair of elliptical wheels be used instead of the gears a¹ and a².
The variable movement above described is communicated to the shuttle b through
a pair of bevel wheels, the one c being mounted on the shaft a8 and the other c¹ on
a short shaft (see Fig. 4) which carries a crank disc e having a crank pin e' to
engage the shuttle carrier c, the arrangement being such that the quicker move-

page_text: ment of the shuttle takes place while it is passing in its lower, circular, forward
path (as shewn in Figs. 1 and 5) through the loop of thread drawn up by the
needle and the slower movement while it is turning over backwards as shewn
at (see Fig. 6).
This turning over backwards of the shuttle which as before stated is done to
prevent twisting of the shuttle thread is brought about in the following manner :-
A pivot d is provided in a slide d' which is operated up and down by a lever d'
(Figs. 1, 2 and 4) and cam d³. The lever being mounted on a pivot d and the
cam on the cam shaft a. When the pivot d is in its lowest positi in it is concentric
with the centre of the crank disc c (as shewn in Figs. 1, 4 and 5) and as it
engages the shuttle carrier c by means of a die d and slot de (the latter of which
is formed in the carrier) it acts as a centre about which the shuttle b and carrier c
revolve during approximately the lower half of the shuttle movement but as soon
as the shuttle & is through the loop of thread drawn up by the needle the pivot d
is gradually raised by the lever d³ and cam d³ while at the same time the crank
pin e continues to revolve which combined movement lifts the heel b of the shuttle
so that the latter moves successively from the position through the position &¹
to the position 62 with its beel at 65 by which time the pivot d and the crank pin c
have each reached their highest positions as shewn in Fig. 6, after which the
pivot d is gradually lowered (while the rotation of the crank pia e continues)
thus throwing up the heel of the shuttle to the position and the point down to
the position the shuttle then assuming the position as shewn in Fig. 6.
preparatory to again passing through the loop of thread next drawn up by the
needle.
The claw e retains the shuttle at its forward end against the flat face fin
contact with which the shuttle moves and the claw el retains the shuttle at its heel
end acting also as a driver. These two claws e and e¹ are attached to or form
part of the carrier and the rear one e' is mounted on a pivot e2 so that it can be
opened backwards for the insertion or removal of the shuttle being retained in
place by a spring pin .
In cases where a large thread and coarse stitches are employed the carrier
is somewhat differently constructed and is mounted directly on the shaft so that
the shuttle then receives a continuous revolving movement point forward in a
circular path.
For the purpose of keeping the shuttle thread out of the way of the descending
needle I make use of a finger g which is mounted on a shaft g' carried in a
bearing and operated by means of two cams g and h. The cam g is mounted
on the shaft a and operates a lever g pivoted to the frame on a pin g and having
a forked end g engaging the shaft g' by means of two collars y' and g. This
arrangement gives a to and fro endlong movement to the finger g.
The cam operates the lever which is mounted on a pivot 2 and engages by
teeth with the segment which is formed on the upper end of the finger g the
lower end of which g" thereby receiving an in and out movement at right angles to
the endlong movement.
The finger g may either terminate in a hook y" (see Fig. 8) or may be an eye
(see Figs. 9 and 10) one half of which i is formed upon the finger g and the other
half upon the piece. The piece partakes of the in and out movement of the
finger g but is prevented from partaking of its endlong movement by having its
upper end formed to engage between the face of the bearing and a piece
attached to the bearing g Slides and are formed to carry the piece
the finger g while yet allowing of the endlong movement of the latter.
upon
The finger end moves backward (see Fig. 1) and to the right behind the
shuttle thread and then comes forward and moves to the left with the shuttle
thread in the half eye i. The movement to the left enclosing the thread between
the one half and the other half which together form an eye and keep the thread out
of the way of the descending needle and when the half again moves to the right
the thread is set free.

page_text: 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 I
claim is :-
In a sewing machine, such as is described in the Specification of former Letters
Patent granted to me No. 23267 A.D. 1892.
1. Imparting to the shuttle a continuous revolving movement point forward in a
circular path and of varying velocity as described and for the purpose specified.
2. Imparting to the shuttle a revolving movement point forward in a circular
path while passing through the loop of thread drawn up by the needle and causing
the shuttle to turn over backwards, after passing through such loop, until in a
position ready to pass through the next loop of thread drawn up by the needle as
described and for the purpose specified.
3. The use of the crank pin a and slotted disc a' set eccentrically to each other
for the purpose of imparting a revolving movement of varying velocity to the
shuttle.
4. The combination of the moving pivot d, slot de, carrier c and crank pin c
for the purpose of giving the backward turn over movement to the shuttle bas.
described and illustrated.
5. The use of a finger constructed and operated as herein described and.
illustrated and for the purpose specified.
W. H. DORMAN.