Improvements in Lock-stitch Sewing Machines.
Year: 1894

page_text: Date of Application, 2nd Mar., 1894-Accepted, 28th Apr., 1894
COMPLETE SPECIFICATION.
Improvements in Lock-stitch Sewing Machines.
I, JOHN GRAHAM, of 8, Palmer Crescent, Kingston-on-Thames, Surrey,
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 reference to two-reel lock-stitch sewing machines. In such
such a machine according to this invention I provide a take-up lever formed
with a hook and operated by means of a special cam so as to take up the thread
between the point of the needle and the material being sewn, after each stitch,
thus preventing the continual friction on the thread caused by its passage through
the eye of the needle which occurs in most machines as hitherto constructed. I
also combine with the reel-holder or shuttle a thread carrier consisting of a pivoted
lever formed with a hooked end, which latter is kept in contact with a groove formed
on the outer surface of the shuttle, by means of a spring so as to carry the thread
loop over and free of the shuttle as the latter is reciprocated below the bed-plate
of the machine; or instead of the aforesaid spring and groove
I may use a guide,
forming part of the shuttle carrier, and construct the thread carrier so that in
combination with the said guide it shall remain in contact with the shuttle during
such time only as the latter is commencing to pass through the thread loop.
In order that my invention may be the more fully understood, I will now proceed
to describe same with reference to the accompanying two sheets of drawings in
which
Fig. 1 is a side elevation, partly in section, of so much of a two reel lock-stitch
sewing machine as is necessary to illustrate the application of my invention,
Fig. 2 is a cross section taken on line xx of Fig. 1 and
Figs. 3 & 4 are plans showing the mechanism underneath the bed-plate.
Figs. 5, 6, 7, 8, & 9, are diagrammatic views illustrating various positions of the
parts at different points of the stroke of the needle,
Figs. 10 & 11 are views showing the modification of the thread carrier.
a is the main driving shaft mounted in the usual manner in the frame b and
operating the reciprocating shuttle carrier bar or lever c by means of the can a³,
shaft a, and crank or lever a³. d is the shuttle and reel holder and c¹ the shuttle
carrier provided with a catch c³ capable of being turned on the pin c³ for removing
the shuttle from or replacing it within the carrier. e is the take up lever or arm
pivoted at e' to the frame b and formed on its lower end with a hook 2. The lever
or arm e is provided with a pin which takes into the path of a cam f fixed to
the driving shaft a being kept in engagement therewith by means of a spring e.
g is the thread carrier hooked at its end g¹ and pivoted at 2 to the bed-plate of
the machine. The shuttle d is formed with a groove d' on its lower outer surface
and the hook g¹ of the thread carrier is kept in contact with the said groove by
means of the spring g³. The path of the cam f is formed with a curved portion f
so as to cause the take up hook e' to travel in a circular direction between the
presser bar and the needle n and between the material being sewn and the point of
the needle when the latter is raised to its highest position.
The operation is as follows; Upon the thread loop being formed in the usual
manner the point or nose d² of the shuttle enters it and the hook g¹ of the thread
carrier carries it round and free of the shuttle as the latter makes its forward
stroke as shown clearly in Figs. 3 & 4. When the needle has completed a stitch
and is raised into its highest position the hook e² is brought down, by means of the
curved path of the cam f, between the point of the needle and the material

page_text: being sewn, and hooks on to the slack portion t¹ of the thread t, the continued
revolution of the cam f forcing the arm e outwards into the position shown in
Fig. 2 thereby drawing the slack thread out with it and keeping it taut until
again required for forming the stitch.
I may provide a guard over the take up lever e, as shown in dotted lines at €³
(Fig. 2) for preventing the cloth getting caught by the thread lifter.
Referring to the diagrammatic views Figs. 5, 6, 7, 8, and 9, Figs. 5 & 6 represent
the shuttle commencing to pass through the loop and the thread carrier g gripping
the loop so as to hold it whilst the shuttle makes its forward stroke, Fig. 7
showing the loop drawn by the carrier g over and clear of the shuttle when the
latter has completed its forward stroke. Fig. 8 shows the needle in its highest
position and the take up hook e brought underneath the point of the needle by
means of the cam f¹ and hooking on to the slack thread. Fig. 9 shows the slack
thread drawn out by the hook e² and the shuttle ready to commence its forward
stroke.
and
In the modification shown in Figs. 10 & 11 I dispense with the spring
construct the thread carrier g of a bent shape as shown. I also provide the
shuttle carrier with a slotted guide h shown more clearly in the end elevation
(Fig. 11,) through this guide h passes the thread carrier 9 which, during the
movement of the shuttle is acted upon by the guide so as to draw the hook g¹
away from the shuttle during the forward stroke of the latter as shown in dotted
lines in Fig. 10, and with it the thread loop whilst during the backward stroke of
the shuttle the hook g' is gradually brought nearer the shuttle until its point
is in the position to engage with a fresh loop as it is entered by the nose of the
shuttle.
My improved machine containing fewer working parts than ordinary two-reel
machines is less liable to get out of order and cheaper in construction, stronger
work is also accomplished by it as the thread is not damaged by friction as in other
machines.
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 :-
1. In a two-reel lock-stitch sewing machine the take up lever or arm e operated
by the cam fso as to take up the slack thread between the point of the needle and
the material being sewn substantially as described and shown.
2. In a two-reel lock-stitch sewing machine the combination with the shuttle d
formed with a groove d' of the pivoted thread carrier g provided with a hook g¹
and a spring g³ substantially as described and for the purposes specified.
3. The modification as described and shown with reference to Figs. 10 & 11 of
the drawings annexed.
4. The improved two-reel lock-stitch sewing machine, combined arranged and
operating substantially as described and shown.
Dated this 1st day of March 1894
F. G. CASSELL,
Of Cassell & Co.,
22, Glasshouse Street, Regent Street, London, W.,
Agent for the Applicant.