IMPROVEMENTS IN SEWING MACHINES
Year: 1885

page_text: I EWALD BRUNCKER Civil Engineer of Sieglar near Troisdorf in the German
Empire do hereby declare the nature of my said invention for "IMPROVEMENTS IN
SEWING MACHINES" and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
These improvements are shown in the accompanying drawings in which Fig. 1
shews a longitudinal section. Fig. 2. a plan after taking away the upper parts.
Fig. 3 is a front view Fig. 4 a transverse section and Figs. 5 to 10 single details.
A. Fig. 1 is the driving axle on whose front end the means for the motion of the
needle rod N are placed. On A is placed the projection B, with the groove b for
the motion of the thread feeder, which consists of a lever C, with the arm C¹; upon
the front end of C, is placed the friction pulley c, in the thread protector c¹, which
on the front part, is cut out in the form of a semicircle, and is bent back so as to
press against the pulley. On the revolving axle C is placed the thread spring c³.
In Figs. 1 to 3 the upper thread goes from the thread reel D, through the hooks g
and gl, situated on the arm G¹, then over to the eye o³ on C, from thence over
the friction pulley g³ situated on the head G, to the pulley c and to the needle N.
c and g are of the same construction and the latter is in Fig. 1' drawn with its
thread protector g³ By this means the thread will be threefold, and therefore the
stroke of the thread lever will be shorter, for the same supply of thread than by
the usual arrangements The height of the stroke of b will also be smaller and
therefore the transmission on C surer, and the whip motioned stroke of the same
avoided.
The thread protectors c¹ and g³ allow the hooking of the thread upon the pulleys,
but prevent the falling off of the same.
Under the base plate G³ lies the axle E whose rotary motion can be received
from A by means of wheels or belts. In Figs 1 and 4 the following arrangement is
shewn. Both parts A and A¹ of the above axle are joined by means of the crank A'
and the pin A Around this is fastened the eye P₁ of the connecting rod P whose
fork P' slides upon the slide block P³ This turns upon the fixed pin P* in the
arm G¹. Upon the axle E. is placed the crank Q¹ which is joined moveable to the
under end of P by means of the joint piece Q'. As is evident E turns itself also after
this manner, if not so uniformly as A still this circumstance can be advantageously
used, as shewn below. Upon E the feeder and the rotary stitch are moved For

page_text: the latter a crank axle F is suitably placed in the front, whose rotation is caused
by E in the following manner Upon one axle is placed a crank W₁ whose
axis W X passes through the point of intersection x of both axles E and F. On
the other hand, upon the other axle, either a circular link v Fig. 1 constructed
with x as centre, or a crank U Figs. 8, 8, 8b, 80, 8d, whose pin axis ux passes
through and whose pin u is fixed to the pin w by means of the joint piece T.
In Fig. 1 the concave link is situated upon E and the crank W on F, on the other
hand in Fig. 7 the convex link is made fast on F and the crank W on E. In
both cases the slide block W situated upon the pin w. is led into the link.
The transmission by means of two cranks W and U by means of the link piece T,
is shewn in Figs. 8° to 8d By means of W and V or W U and T, F receives an
irregular motion, by the regular rotation of E, which is used for the stitch forming
motive apparatus driven by means of F. If as shown in Fig. 1 E be driven
irregularly from A by the motion of the cranks; then this irregularity can be
regulated by means of the position of the crank Q to the transmitting organ
situated on the front end of E in a manner favourable for the motion of the stitch
forming apparatus.
The fastening of the needle rod in the needle rod N is shewn in Figs. 9 and 10
The rod N has a slot N with a needle groove n¹. n is partly filled by the
cylindrical segment n³. In order to hold the same the ring n with the screw n is
placed around N; situated between N and n¹, and by the screwing fast of n³
against the needle N¹ which is thus pressed in its groove whereby it will be
held fast.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The thread lever C in connection with the leading eye situated on it at the
head G, and the friction pulley provided with a covering for the lessening of the
falling off of the thread. By means of the eyes, friction pulleys and the above
named thread tension the thread is led so that a threefold folding of the same
ensues, by means of which for the same supply of thread the whipping motion of
the thread lever is avoided.
2. The transmission of the rotary motion of the above axle A to the lower
axle E, by means of the cranks A' and Q1 situated upon them with the connecting
rod P sliding on the fixed pin P₁, and the joint piece Q.
3. The transmission of the rotary motion of the axle E to axle F serving for the
motion of the rotary stitch forming apparatus, since upon one of the axles, the
crank W is placed, whose pin axis goes through the point of intersection of both
axles, while upon the other axle is either :-
a) a circular link constructed with the point of intersection as centre, or
b) a crank U whose pin centre goes through the point of intersection of both
axles and is joined to W by means of a joint piece T.
4th The fastening of the needle N¹ in the rod N by means of a cylindrical
segment n held in the slot n' by means of a ring n³, which is pressed by means of
the screw n' in n³ against the needle in the groove n.