Improvements in Lock Stitch Sewing Machines.
Year: 1893

page_text: Date of Application, 21st June, 1893
Complete Specification Left, 13th Dec., 1893-Accepted, 10th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Lock Stitch Sewing Machines.
GEORGE HARRY SCETRINI of No. 1 Lesley Street Barnsbury, London North,
Mechanic GEORGE CADE of No. 12, Cumberland Street Barnsbury London
Mechanic and HERBERT KYNASTON BRIDGER of Falcon Court, Fleet Street,
City of London, Gentleman, do hereby declare the nature of this invention to be
as follows:-
This invention has for object
1. A novel arrangement of known parts of sewing machines in which waxed or
plain threads are used for sewing leather such as the soles of boots and shoes,
harness and the like or other comparatively hard substances.
2. A new or improved method of or appliances for freeing the loop thread from
the needle hook while passing around the spool.
3. A novel method of forming the pocket in which the spool is held to enable
the loop to escape the stop just prior to or simultaneously with the first motion of
the "take up."
4. An improved method of or means for operating the "awl" appliances and
for effecting the piercing and the feeding motions thereof.
5. A novel method of and appliances for operating the presser leg.
The machine consists of a base with back uprights at the side for carrying the
main shaft and the operating cams said uprights having as part of same front or
forwardly projecting arms to carry the top operative detail mechanism by a dummy
shaft and the base has a front slot or recess for the lodgment of the lower operative
detail mechanism, all of which receive motion from the cams on the rear shaft,
levers being so arranged therefrom that the various movements follow in regular
order but subject to adjustment to suit the class of work intended for the machine.
All the motions are positive and the retirement of the parts are not dependent
upon springs as with machines at present employed for the purpose.
The needle affixed to a quadrant on the dummy shaft moves downwardly
circularwise under the action of a lever which in the return causes the needle to
pause and then to go a slight distance up to release its claw or hook from the loop
which it had previously brought down for the "shuttle hook to draw in round
the spool instead of the "take up dragging the loop off the needle as at present
and by which the thread gets chafed and the fibres torn out and shredded.
"
"
The pocket of the spool holder is excentric at part of its inner periphery to
permit of the spool being lifted by the tension of its thread, and then to fall as the
thread passes the vertical centre, the spool by this means will clear the stop for a
free pull on the thread by the take up.
The awl appliance is controlled by a lever and cam which lift it with a forward
action to pierce the leather, then with a straight forward motion to feed, then
downwardly for release, and finally a straight back travel to its first position.
The presser leg is operable from a back sliding pivot, or a slot over a stud when
a head piece is forced on it.
T
1000

page_text: Improvements in Lock Stitch Sewing Machines.
We, GEORGE HARRY SCETRINI, of No. 1 Lesley Street, Barnsbury, London,
North, Mechanic, GEORGE CADE, of No. 12 Cumberland Street, Barnsbury,
Loudon, Mechanic, and HERBERT KYNASTON BRIDGER, of Falcon Court, Fleet
Street, City of London, Gentleman, 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 object :—
1. A novel arrangement of known parts of sewing machines, in which waxed or
plain threads are used for sewing leather, such as the soles of boots and shoes,
harness and the like, or other substances.
2. A novel method of forming the pocket in which the spool is held to enable the
loop to escape the stop just prior to or simultaneously with the first motion of the
"take up."
"
3. An improved method of or means for operating the "awl" appliances, and for
effecting the piercing and the feeding motions thereof.
4. A novel method of and appliances for gripping the presser bar or foot to
temporarilly fix the work.
The machine consists of a base with back uprights at the side for carrying the
main shaft and the operating cams, also front or forwardly projecting arms to
carry the top operative detail mechanism by a dummy shaft, and the base has a
front slot or recess for the lodgment of the lower operative detail mechanism, all of
which receive motion from the cams on the rear shaft, levers being so arranged
therefrom that the various movements follow in regular order but subject to
adjustment to suit the class of work intended for the machine.
All the motions are positive and the retirement of the parts are not dependent
upon springs as with machines at present employed for like purposes.
The needle affixed to a quadrant on a dummy shaft moves downwardly circular-
wise under the action of a lever, and cam the latter of which is formed to allow the
needle to pause and then to go a slight distance up to release its claw or hook from
the loop which it had previously brought down for the "spool hook
" to draw in
round the spool instead of the "take up" dragging the loop through the needle
as at present, by which the thread gets chafed, and the fibres torn out and
shredded.
The pocket of the shuttle is eccentrically formed at part of its inner periphery to
permit of the spool carrier being lifted by the tension put upon the loop by the
take up and then to fall as the loop passes the vertical centre, the spool carrier
projection by this means will clear the stop for a free pull on the thread by the
take-up."
The awl appliance is controlled by levers and cams which lift it with a forward
action to pierce the leather, then move it with a motion to feed straight
forwardly, then downwardly for release, and finally a straight travel back to its
first position.
Our invention is indicated on the annexed drawings.
Figure 1 is an elevation from the right hand of the machine.
Figure 2 an elevation of the left hand of the machine with the side frame
removed.
Figure 3 front elevation.
Figure 1 nontial alan akom

page_text: Figure 6 detached view of the bobbin box with the appliance for clearing the loop
thread for the "take-up" to draw the thread in without friction.
Figure 7 section of bobbin box and carrier.
A the base. B, B, side cheeks therefrom. C main shaft to be driven by hand or
power from either end, as convenient. D feed cam. E needle cam. F looper
cam. G cam for operating piercing awl. Htake up" cam.
I spur wheel.
jpart of cam E for effecting dip of needle all the cams being mounted on main
shaft C at back of machine. The spur wheel I gears into an intermediate
wheel K, and this gives motion to the pinion L in the shuttle race M for a double
rotation to that of the spur wheel I, so that the hook N shall only engage loop
of thread when presented at each alternate revolution; a plan which enables
the parts to be arranged in very compact order and reduces the depth of the
machine.
P, Q, are the forwardly projecting arms between which at the lower part thereof
is fitted the shaft T for carrying the awl lever R and quadrant S respectively.
The "take up" and tension mechanism is fitted upon the plate formed at the top
in a piece with the projecting arms, and this with a division plate between the
shaft 1 and the beforementioned top plate, forms a convenient bearing for carrying
the table V, thread guides and looper mechanism.
The intermediate gear wheel K and shuttle race M is secured to one of the
projecting arm sides, and the looper operating mechanism to the other.
The material U to be sewn or stitched is placed on the table V, when not sewing
aloft, the presser foot. W is placed in the channel previously made in the leather in
which it acts as a guide for the work as it is moved along.
The main-shaft C is then rotated for the piercing awl X to be moved upwardly
and laterally to feed the work by means of the cams G, D, and levers R, Z, a, b,
the awl X then lowers and retires sideways to leave the hole so made in the leather
over the needle c which now rises into and through said hole under the action of
its cam E and link S, the looper d now revolves under the control of the pinion e
and rack by the levers 9, 9, y, from the cam F, and wraps or curls the upper
thread around the needle just behind the barb and simultaneously with the needle's
descent, the looper d is reversed to clear itself from the upper thread, so that the
needle c can draw the thread down and form the loop, which when the needle c has
descended to the bottom, is in the path of the revolving hook N of the spool
carrier h, which under the action of the gear I, K, L, engages in the loop i at
which moment the needle e rises a little by its link S, being struck by the
projection of the cam E to free itself from the thread loop which the hook now
drags about half round the spool carrier h and then throws it off in the manner well
known in spool sewing machines, whereby the spool thread becomes locked in the
loop i. The "take up" k now comes into action to draw the loop back through
the work, the thread of the upper reel being held tight by teeth 7 of the lever m
engaging the teeth of the ratchet wheel n which is temporarily freed when the
lumpp strikes the lever m to withdraw the teeth from the wheel n and allow
the wheel n to rotate for the reel thread to be drawn while the loop is being made,
the pressure put upon the presser foot W by its spring being locked by the
roughened face gripper » under action of the bolt operated by the lever s and
cam t.
"
The "take up k is of the roller kind on the arm u and is operated by the link
on the main shaft C, the roller u being when necessary relieved by the spring to
prevent undue strain on the thread. At the moment the stitch is completed by the
"take up," the roughened or detent gripper is withdrawn ready for the work to
be pushed along by the feeding awl X.
The spool y is contained in the carrier h and its thread is led through a hole z in the
carrier from a point next where the nose of a stop a¹ presses, and it is against and
slightly under this stop that one side of the loop is temporarily held until the
"take up" puts a strain upon the loop to draw in the slack, said strain exerting a
pull on the spool carrier to lift it for the loop thread to pass freely up between

page_text: the lump 6' and the stop a', the pocket in which the spool carrier has its lodgment
being hollowed at the top, or its pocket is eccentrically formed to permit the lift of
the spool carrier, as particularly shown at Figures 6, and 7 of the accompanying
drawings.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed we declare that what we
claim is.-
1. The particular arrangement of appliances constituting a lock stitch sewing
machine, as shown on the annexed drawings, the several parts acting in the manner
and for the purposes described.
2. Specially in the machine shown, the means or appliance for freeing the loop
thread from the needle hook i.e. the internal cam lump for raising the needle, as set
forth.
3. Eccentrically forming a portion of pocket in which the spool is lifted by the
tension put upon the loop thread by the take up and then to fall as the said thread
passes the vertical centre, as described and substantially as shown on the drawings.
December 1902
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said George Harry Scetrini, George Cade, and
Herbert Kynaston Bridger.