Improvements in or relating to Take-up Mechanism for Sewing Machines.
Year: 1894

page_text: Date of Application, 20th Feb., 1894-Accepted, 14th Apr., 1894
COMI DEMIE DIEULTIVATION.
Improvements in or relating to Take-up Mechanism for Sewing
Machines.
I, REGINALD HADDAN, of the Firm of Herbert Haddan and Co., of
18, Buckingham Street, Strand, W.C. London, Patent Agent, do hereby declare
the nature of this invention, a communication to me from abroad by The Scott
Shoe Machinery Company, of 186, Grand Street, New York, in the United States
of America, and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
The object of this invention is aftake-up mechanism which by a comparatively
short movement of the take-up lever serves to draw the stitch tight and to
draw out a sufficient quantity of the sewing thread to form a loop which can be
drawn through the work by the needle and passed over the shuttle or bobbin
holder which carries the thread for locking the stitch in a lock-stitch sewing
machine.
My take-up mechanism is intended particularly for wax thread sewing machines
such for instance as described in Letters Patent of the United States No. 366,935
granted to Christian Dancel July 19, 1887, or in Letters Patent of the United
States No. 497,690 granted May 16, 1893, but it can be used with advantage for
other kinds of lock-stitch sewing machines.
In the accompanying drawing
Figure 1 represents a perspective view of the take-up mechanism detached.
Figure 2 is a front elevation of the same.
Figure 3 is a vertical section in the plane y y Fig. 2.
Figure 4 is a sectional side elevation of part of a wax thread sewing machine
embodying my invention.
:
Figure 5 is a transverse vertical section of the tension device in the plane xx
Fig. 4.
In these drawings the letter A designates the take-up lever which is mounted on
a stud a secured in a portion of the frame B and to which an oscillating motion is
imparted by a cam or other suitable mechanism in a manner well known to those
skilled in the art. In the free end of the lever A is secured a stud b which forms
the bearings for two pulleys C C₁ each provided with a groove c c¹ respectively and
which revolve freely one independent of the other on the stud b. In the frame B
is mounted a stationary bearing composed as here shown of a stud d which supports
two pulleys E E¹. These pulleys rotate freely one independent of the other on
the stud and they are provided with grooves e e¹ respectively.
The sewing thread T passes from the tension to the take-up mechanism and
thence to the work W in the following manner : The branch 10 passes from the
tension into the groove e of pulley E and over the outside portion of this pulley ;
the branch 11 of the thread passes from the groove e to the inside portion of the
groove c in pulley C and the branch 12 of the thread passes from the outside of
pulley C to the inside of pulley E' and into the groove e¹ of this pulley and the
branch 13 of the thread passes from the outside of the groove e' into the inside of
groove c' in pulley C¹ and the branch 14 runs from the outside of the groove c¹ to
the work W as seen in Fig. 1. By referring to Figure 1 it will be seen that in the
example illustrated in this figure the work W rests upon a support I and the locking
thread is situated above the work, the loop L of the sewing thread being represented
in the position which it occupies when it has been partially drawn up by the action
of the take-up mechanism.
In Figure 4 I have shown part of a sewing machine which is described in the

page_text: United States Patent No. 497,690 above mentioned in which I designates the work
table or support and L is the loop of the sewing thread after the same has been
drawn up through the work by the needle n. This needle is situated above work
support and is actuated as described in United States Patent No. 366,935 above
mentioned. F is the loop carrier which serves to spread the loop L and to pass
the same over the bobbin holder G and after the loop has passed over the bobbin
holder, it embraces the bobbin thread t as shown in Fig. 1 of the drawing.
*
The sewing thread T is drawn from the wax pot H round the tension roller R to
the take-up mechanism and this tension roller is exposed to the action of friction
disks which can be pressed up against its faces with more or less pressure as
shown in Fig. 5. The take-up lever A connects by a link 25 with a lever 26 which
has its fulcrum on a stud 27 fixed in the frame of the machine and which carries a
roller stud 28 that engages a cam groove 29 in a hub mounted on the main shaft of
the sewing machine.
When the working parts of the take-up mechanism are in the position shown
in Figure 1, the take-up lever A moves in the direction of arrow 1, and since the
strand 10 of the sewing thread T is held back by the tension R, the strand 14 is
drawn downward and the pulley C₁ which is rotated in the direction in which the
strand 14 travels, must rotate in the direction of arrow 2, the strand 13 moves in
the direction of arrow 4 and the strand 12 in the direction of arrow 6, so that the
pulley E¹ turns in the direction of arrow 5 and the strand 11 which connects with
the strand 10 of the sewing thread remains stationary. At the same time as the
pulleys C C move downward, all the strands 11, 12, 13 and 14 must be elongated
and since the thread required for this purpose must come from the strand 14, a
downward motion of the lever A for one quarter inch requires one inch thread.
Consequently by a comparatively small downward motion of the lever A the loop L
is drawn up tight and as the downward motion of the lever A continues, after the
stitch has been drawn tight, a sufficient quantity of the sewing thread is drawn out
from the wax pot H (the friction of the tension roller being overcome by the
lever A) to enable the needle n to draw the sewing thread up through the work
and to form the loop L (Fig. 4), and when the loop carrier F enters this loop and
draws it over the bobbin holder G, the lever A is carried up by its cam in the
manner illustrated in United States Patent No. 366,935 above mentioned, so that
the pulley C comes nearly in contact with the pulley E.
From this description it will be understood that all the thread required for each
stitch is drawn out of the wax pot by the action of the lever A and the stitch
forming devices have not to overcome the resistance of the tension, neither have
they anything to do with the operation of drawing the stitches tight. It will also
be seen that while the pulley E remains stationary during the downward movement
of the pulleys C C', each of the pulleys E', C, C₁ rotates but the pulley C' rotates
faster than the pulley E' and this pulley E' rotates faster than the pulley C and for
this reason it is desirable to mount the pulleys E E' and C C' in such a manner that
tbey can rotate one independent of the other.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is.
The combination with stitch-forming devices, a tension device, a pivoted take-up
lever, and means for actuating the lever, of a stationary bearing d carrying two
independently rotatable pulleys E and E¹, each having a peripheral groove, and a
stud 6 mounted on the free end of the take-up lever aud carrying two independently
rotatable pulleys C and C' each having a peripheral groove, substantially as and
for the purposes described.
בז
ليوم
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2004