Improvements in Lock Stitch Sewing Machines.
Year: 1896

page_text: Date of Application, 18th Dec., 1896
Complete Specification Left, 18th Sept., 1897- Accepted, 18th Dec., 1897
PROVISIONAL SPECIFICATION.
Improvements in Lock Stitch Sewing Machines.
THOMAS COCKBAIN No. 3 Ellesmere Grove Wellington Road Eccles Near
Manchester Tailor do hereby declare the nature of this invention to be as
follows:-
My invention consists substantially of mechanism whereby the said machine
can be run continuously until say one thousand yards has been used from the
bottom or under cotton. Hitherto, in all other existing machines, the length of
bottom or under cotton has been limited to the amount carried by the spool
or metal bobbin in the shuttle that is to say, under forty yards whereas, in my
invention, in lieu of the ordinary shuttle, used on all other machings, a cylinder
capable of carying a large wooden bobbin is used. The capacity of the said
cylinder so far as the length of cotton is concerned-is practically unlimited
thus doing away with the freqaunt rewinding of spools or metal bobbins necessary
on all other machines The cotton being taken direct from the said wooden
bobbin in the said cylinder, wheel take up tension being provided.
This invention consists of a Lock-stitch Rotary Machine, fitted with crank-
motion, oscillating-pitman, Disc or cylinder carrier, thread kicker, cylinder lifter
and wheel take-up tension. A balance wheel for operating the machine with the
main shaft driven by a wheel and on the end of this shaft is a disc with roller
stud to fit into hollow cam for operating the needle bar. The tension is provided
with a wheel for taking up the slack of the thread. When operating the tension
wheel I employ a cam operated from the upright shaft. The feed motion is
effected and controlled by a series of cams operated from the main crank with
stitch regulation and swivel joint. The regulator has a thumb screw acting in a
slot for adjusting the length of the stitch. The thumb screw is moved right
or left to regulate the stitch. The cylinder is carried loosely in bearings fixed to
the under-side of the bed-plate. The cylinder and bearings are driven from the
main crank with oscillating stud and pitman, disc and crank stud. When needle
goes down the throat plate the loop former on the cylinder takes the loop from
the needle and passes it over half the cylinder case, the thread kicker completes
the other half and the tension wheel takes up the slack thread and completes the
stitch

page_text: in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention is designed to enable the machino to run for a longer period
without replenishing the supply of the under thread or cotton.
Hitherto the bottom or under thread has been wound upon small metallic
spools or bobbins to be placed within the shuttle, and the length that such are
capable of holding, is limited to about forty yards, whereas by this present inven-
tion, the shuttle is so constructed as to be capable of carrying a large wooden spool
or bobbin, containing up to 1000 yards of thread, thus obviating the necessity for
rewinding the small spools.
The invention consists essentially in constructing the machine with a large
cylindrical shuttle or cylinder capable of carrying an ordinary wooden spool of
thread, suitable mechanism for rotating and actuating such shuttle, a device for
drawing down the upper thread, and forming a loop for the cylindrical shuttle
to pass, and a wheel or rotating device for taking up the slack of the thread.
It will be fully described with reference to the accompanying drawings.--
Fig 1. Side elevation with the front plate removed.
Fig 2. End elevation.
Fig 3. Plan..
Fig 4. Sectional elevation of head showing the cam for operating the needle
bar.
Fig 5. Section of rotary device for taking up the slack of thread.
Fig 6. Side elevation of the cylindrical shuttle.
Fig 7. Plan of same.
Fig 8. Plan of same from below.
Fig 9. Side elevation from opposite side to Fig 6.
Fig 10. End elevation showing nose of shuttle.
Fig 11. End elevation from opposite end.
Fig 12. Perspective view of the looper or cradle for carrying the spool cylinder.
Fig 13. Plan of cylinder for carrying the spool.
Fig 14. End view of same.
Fig 15. Plan view of saddle. upon which the looper or cylinder cradle rests.
Fig 16. End view of same.
Fig 17. Side elevation of the lifter of the cylindrical shuttle.
Fig 18. End elevation of same.
Fig 19. Plan of same.
Fig 20. Front elevation of stationary cam or platform upon which the lifter
is raised.
Fig. 21. Plan of same.
The head or framing of the machine is of any ordinary construction with a
driving shaft A from which the several operative parts of the machine are driven.
The needle bar B is driven by an eccentric pin a carried by a disc on the end of
the shaft A, engaging in the race of a cam plate b attached to the needle bar in
the usual way. The shape or formation of the groove or race in the cam plate b
is of the shape shown by dotted lines in Fig. 2, and such as to give the desired
movements to the needle bar B.
At the other end of the head is placed the secondary driving shaft A¹ which
receives continuous rotary movement from the shaft A, through the bevel
wheels a¹. On this shaft are fixed three cams C D and E and an eccentric F,
by which the other parts of the machine are actuated.
The cam C operates the wheel take up G imparting to it an oscillating rotary
movement to take up the thread formed, by the thread lever or looper H. The
wheel take up G is mounted upon the end of the shaft g which is rotated by the
bevel wheel g¹ upon the other end. A pivoted quadrant or wheel G¹ gears with
the bevel g, and receives a reciprocating movement from the bell crank lever c
to which it is connected by the connecting rod or link C. The bell crank lever

page_text: is pivoted to a lug attached to the framing and is oscillated on ita pivot by the
cam C as it rotates.
The take up wheel G is provided with a groove around its periphery, with a
ring or flange G screwed on at one side by which the width of the slit leading
to the groove is adjusted to regulate the slack of the thread, and prevent it passing
too quickly to the cylindrical shuttle K.
Below the needle bar B3 on the under side of the bed plate is placed a thread
lever H which receives the thread from the needle and carries it down in a loop
to allow the shuttle K to pass through. The outer end h is formed with a slit cr
slot through which the needle passes and carries the thread, and as the needle
rises, the thread is drawn down by the lever as it descends. It is pivoted to the
under side of the bed plate and is operated by the lever d which engages with and
is oscillated by the cam D.
The feed bar J which is placed in the usual position under the bed plate, is
operated by the lever E which receives motion from the cam E on the second
driving shaft A. The cam E is preferably formed with a double throw and
imparts to the lever E, an oscillating and reciprocating longitudinal movement,
to give the necessary reciprocating and rising and falling movements to the
feed bar J. The lever E' is provided at one end with a rectangular cam socket e,
which embraces the cam E, and at the other with an inclined wedge el which passes
under and raises the feed bar J which is drawn down again by the spring i. The
lever E is pivoted in a swivelling nut or bracket, on the sliding bar J which can
be moved to and fro, and secured by a thumb screw to regulate the length of
the stitch. The screw passes through a slot in the bed plate and is clamped
thereto when the screw is tightened.
The under thread is carried by the cylinder or rotating shuttle K which is
caused to rotate at each stroke of the needle bar B. It is supported loosely upon
a fixed bar or bearing L, and is rotated by an oscillating, reciprocating connecting
md F¹, one end of which is connected to the pin f of the eccentric or crank F,
and the other end to a pin m on a crank or eccentric M pivoted to the underside
of the cylinder. The oscillating reciprocating connecting rod F slides to and fro
in the bracket f, which is pivoted by means of a stud f to a pillar (or lug pro-
jecting from the under side of the bed plate.
The cylinder or shuttle K comprises 'the saddle N (see Figs. 15 and 16) which
rests and swivels upon the fixed bar or bearing L, the cradle and loop former O
(see Fig. 12) which fits into and is carried by the saddle N, the cylinder P (see
Figs. 13 and 14) fitting into the cradle O which carries the spool or bobbin of under
thread and the lifter R (see Figs. 17, 18, 19) which rests upon the saddle N, and
surrounds the cradle and loop former O.
The saddle N is preferably formed rectangular at one end and semi-circular at
the other with a pin or stud n projecting from the under side. It rests upon the
bar L and the pin n passes through and has affixed thereto on the under side,
a disc S carrying an eccentric pin s to which the crank or eccentric M is connected
and through which the rotary motion is imparted from the reciprocating con-
necting rod F. The disc S is fixed to the stud n by a pin or cotter s passed
through both, and the relative positions of these can be adjusted by altering the
position of the pin s¹. The rectangular end of the saddle Ñ is provided with an
adjustable plate n secured by a set-screw which can be moved to take up any
wear between it and the cradle O. The circular end of the saddle N is provided
with a flange with two holes n to receive the guide pins r of the lifter R.
The cradle O fits into the saddle N, and is formed at one end with a hook or
loop carrier o, and at the other end with a curved side with an inclined slot o¹
through which the thread passes. Beneath the hook or loop carrier o is a pro-
jection which fits into a corresponding recess in the saddle N. Between the
two ends the cylinder or carrier P fits.
The cylinder or bobbin, carrier P is of tubular form with a spindle p for the
bobbin, and a slide pl to fit into a corresponding groove o in the cradle 0. On

page_text: the top of the cylinder is a slot p" for the thread to pass through, and a tension
plate 3 secured with a regulating screw, and a cover p with a guide eye 15 at
one end, prevents the thread passing in the wrong direction.
The liftor R is of horse shoe shape with guide pins r which fit into the holes "l
of the saddle N. On its under edge it is fitted with runners r which traverse the
cam plate T, which is so shaped as to lift it and raise the cradle O out of contact
with the saddle N, to allow the thread to pass under it to form the locking loop
of the stitch. To one edge is fitted a small guide plate to guide the loop of
the thread between it and the cradle O, and prevent the thread passing down tho
outside of the lifter. A spring U is attached to one side of the lifter R to keep
the cradle or lapper O in position, and a spiral spring a draws the lifter R down
again after it has been raised.
The cam plate T (see Figs. 20 and 21) is stationary, and is attached by a
lug to the projection or pillar on the under side of the bed plate.
In operation two spools or hobbins of thread V and W are employed, the top
one placed upon a spindle on the top of the frame and the under one W ou
the spindle in the spindle or bobbin carries P. The top thread V passes from
the spool or bobbin around an ordinary tension, then down through the front
guide eye on the centre of the take up wheel G, and thence through the slot
in the rim around the groove of the take up wheel G, and afterwards through the
guide eye on the face plate and the eye of the needle. The under thread W
passes from its spool or hobbin in the bobbin carrier or cylinder P through the
slot p over the tension spring or catch 73. back under the slot cover 7 and through
the guide eye 5 in the end of the cylinder, and then through the inclined slot
or notch at the end of the saddle or looper O. The two threads are then brought
together above the plate, and are held when the machine is set in motion, until the top
thread V has caught or looped the under thread W, and brought it above the bed plate.
The material to be stitched is placed in position in the ordinary way, and the needle
carries the top thread V down through the material and through the slit in the
thread lever H. The needle remains stationary until the hook or looper on the
end of the cradle O of the shuttle K catches the thread and the needle then rises.
The lever H descends to draw the thread downward after the shuttle has moved
half a revolution. At the same time the take up wheel G is rotated and releases
sufficient thread to pass under the cradle of the shuttle. As soon as the thread
is drawn down by the lever H, the lifter I traversing the cam plate T raises the
cradle or looper O, and permits of the thread being drawn under it, thus forming
the desired locking loop with the under thread W. The rotation of the take up
wheel G in the opposite direction, winds up the slack firead and completes the
stitch. The saune cycle of operations is repeated at each stroke of the needle and
needle bar.
Having now particularly described and ascertained the nature of the said in-
vention and in what manner the same is to be performed, I declare that what
I claim is..
1. A sewing machine constructed with a rotating cylinder shuttle, capable of
carrying an ordinary spool or bobbin of thread with a rotary take up device to
release and take up the desired quantity of thread, substantially as described.
2. A sewing machine constructed with a rotary cylinder shuttle provided with
loop former and bobbin carrier a lifter to raise the loop former to allow the
thread to pass under, a thread lever to carry the top thread down around the loop
former, and a take up wheel to release and take up the desired length of the top
thread, substantially as described.
3. In a sewing machine the combination with the shuttle of a thread lever
to carry the top thread down as the needle rises to form a loop through which the
shuttle passes, substantially as described.
4. In a sewing machine the combination with the shuttle and top tension of
a rotary take up wheel or device by which the thread is released, to permit of the

page_text: formation of a loop for the shuttle to pass through and take up to complete the
stitch substantially as described.
5. A rotary shuttle for a sewing machine capable of carrying a spool or bobbin of
thread, having the several parts constructed and arranged in combination sub-
stantially as described.
6. A sewing machine constructed and arranged, substantially as and for the
purposes described and shown.
Dated this 17th day of September. 1897.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester,
Patent Agents.