IMPROVEMENTS IN SEWING MACHINES FOR ELASTICS FOR BOOTS AND " SHOES
Year: 1878

page_text: LETTERS PATENT to Carl Pieper, of Dresden and Berlin, for the Invention
of IMPROVEMENTS IN SEWING MACHINES FOR ELASTICS FOR BOOTS AND
"
SHOES." A communication by Nicolaus Dürkopp, of Bielefeld, Prussia.
PROVISIONAL SPECIFICATION left by the said Carl Pieper at the Office
of the Commissioners of Patents on the 22nd January 1878.
CARL PIEPER, of Dresden and Berlin. "IMPROVEMENTS IN SEWING MACHINES
FOR ELASTICS FOR BOOTS AND SHOES." A communication by Nicolaus Dürkopp, of
Bielefeld, Prussia.
This Invention relates to certain improvements in sewing machines, and especially
to machines adapted for sewing elastics for boots and shoes.
Hitherto the feed motion of sewing machines has been placed either above or
below the cloth plate. In some cases however it may be advantageous to have a
feed motion above and another one below, so that either may be used according to
desire.
In many systems of sewing machines the introduction of such an arrange-
ment would not present any difficulty, but in machines for elastics, which require
a long and narrow arm for slipping the piece of work over whilst being sewn, and
which have hitherto been provided with a top feed motion only, the arrangement of
a bottom feed is difficult on account of the very limited space at disposal for the
purpose.
According to this Invention they may however be fitted with a bottom feeding
device in the following manner :-To the present cam disc actuating the needle bar
a bevel wheel is fixed gearing into a similar wheel on a shaft placed in the said arm

page_text: of the machine. On the end of this shaft a small eccentric is fixed, which actuates
a slide moving in a horizontal dovetailed slot. This slide is shifted in one direction
by the eccentric, and in the other by a spring. In a vertical dovetailed slot of the
slide a serrated cloth propeller moves up and down, being raised by the same
eccentric and depressed by a presser foot actuated by a suitable spring. By the
action of the eccentric on the slide and on the propeller the latter receives a com-
bined horizontal and vertical motion, as required in sewing machines, for the pur-
pose of propelling forward at every stitch the material to be sewn.
For regulating the length of the stitch there is a screw opposite to the end of the
slide which by being screwed further in prevents the latter from being drawn back
to the full amount of its course by the spring attached to it.
This feeding device may be used independently, or it may be combined with a
top feed motion. When in the latter case the bottom feed is to be used the top
feed must be put out of operation by any suitable means; the presser bar is pre-
vented from oscillating by passing a cotter through the head of the machine and
behind the presser bar, and a smooth presser foot, the new serrated cloth propeller is
slipped into its groove, and a cloth plate having an opening for the latter to pass
through is put into the place of the ordinary one.
For the purpose of better regulating the tension of the upper thread a tension
lever pivoted to a bracket in the head of the machine passes through a fork on the
needle bar, and a screw acting on a spring fixed to the end of the said lever serves
to regulate the tension of the thread.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Carl Pieper in the Great Seal Patent Office on the 19th July
1878.
CARL PIEPER, of Dresden and Berlin.
"IMPROVEMENTS IN SEWING MACHINES
FOR ELASTICS FOR BOOTS AND SHOES." A communication by Nicolaus Dürkopp, of
Bielefeld, Prussia.
This Invention relates to certain improvements in machines for sewing elastics in
the manufacture of boots and shoes.
Hitherto the feed motion of sewing machines has been placed either above or
below the cloth plate. In some cases however it may be advantageous to have a
feed motion above and another one below.
In many systems of sewing machines the introduction of such an arrangement
would not present any difficulty, but in machines for sewing elastics and certain
Machines intended for this purpose
other parts of boots and shoes this is different.
are provided with a long and narrow arm, over which the piece of work is slipped,
and which contains the shuttle and its driving gear. This arm presenting a very
limited space for any further mechanism, the said machines have hitherto always
been provided with a top feed motion only.
Whenever delicate materials, such as japanned leather, are sewed by a machine of
this arrangement the serrated driving foot is very apt to make impressions in the
material which are visible when the work is finished. It is therefore of great
advantage to have a bottom feed by which this inconvenience is obviated.
The object of this Invention is now to provide the said sewing machine with a
bottom feed in addition to the top feed motion, so that the one or the other may be
used according to desire.
The mechanical arrangement which I have designed for the said purpose is repre-
sented on the annexed two Sheets of Drawings.
Fig. 1 is a front elevation of the entire sewing machine; Fig. 2, a back view of
the same; Fig. 3, a horizontal section on line C, D; Figa 4 and 5 are vertical
sections according to the lines A, B, and J, K; Fig. 6 represents several parts in
detail; Fig. 7 is a horizontal section on line G, H; Fig. 8 shows the two cam disks b
and c; and Fig. 9, the take-up lever R.
On the main shaft a of the machine two cam disks b and c are fixed, the disk b
actuating the needle bar by means of the lever M, and the disk c driving the
shuttle gear as usual. To the boss of the disk b a small bevel wheel d is fixed
On the other end of the latter there is
which gears into the wheel fon the shaft e.
a small eccentric g, Figs. 3 and 6, which actuates the new feeding device, consisting
of the slide h, and the serrated cloth propeller i. The slide h, moving in a hori-
zontal dovetailed groove h', is shifted in one direction by the eccentric g, and drawn
back by a spring q¹ lying in a perforation of the slide. In a vertical dovetailed
groove of the said slide the serrated cloth propeller i moves up and down, being
raised by the eccentric g and depressed by the smooth presser foot k actuated by a
spring attached to the head of the machine and to lover B, Fig. 2. By the section
of the eccentric g on the slide h and on the propeller i, the latter receives a com-
bined horizontal and vertical motion as required in sewing machines for the purpose
of propelling forward at every stitch the material to be sewed.
act on the ends of
The screw m serves to regulate the length of the stitch. By being screwed
further in it prevents the slide h from being drawn back to the full amount of its
While the
course by the spring 7', thereby causing the stitch to become smaller.
ordinary top feeding mechanism is being used the cams r and
the levers A and B in the ordinary manner. The lever A raising the cone, Figs. 5
and 7, causes it to oscillate the presser bar p so as to move the cloth forward.
Previously however the lever B must have acted on the bar p from above for
the purpose of making the presser foot bear on the cloth. Moreover, in this

page_text: case the presser foot must be provided with serrations (see 9, Fig. 6), and the
cloth plate l, Fig. 6, has only a hole for the needle to pass trough.
When the bottom feeding device is to be used the levers A and B must be put
out of action. These levers are provided at their ends with screws, on which the
eccentrics or cams r and 8 act. By turning back the said screws so as to bring them
out of the reach of the eccentrics, the levers are prevented from being oscillated by
the latter. (Instead of these screws any other suitable device may be applied for
the same purpose.)
The lever B when put out of positive action is constantly pressed on the presser
bar by the spring shown in Fig. 2, so that the foot of the said bar is kept in contact
with the cloth, &c., while it follows the up-and-down motions of the propeller i
The presser bar must however be prevented from oscillating and from turning, and
for this purpose a cotter n is passed through an aperture in the head of the machine
and behind the presser bar (see Figs. 5 and 7). Moreover, the smooth presser foot k
is substituted for the serrated foot q, the cloth plate is detached, the cloth pro-
peller slipped into its groove in the slide h, and the cloth plate having an
opening for the propeller to pass through is screwed on. The machine being there-
upon put in motion, the lower feeding device will operate as stated above.
For the purpose of providing better means for regulating the strain on the upper
thread the take-up or tension lever R has been provided with a spring u and an
adjusting screw u, see Figs. 1 and 9. The lever R is pivoted to a bracket on the
head of the machine, and passes through a fork attached to the needle bar. The
said spring u, Fig. 1, is hooked with one end into an eye in the back arm of lever R,
and with the other to the screw u¹ passing through an arm of the bracket. By
turning the nut of this screw, which may be done while the machine is working, the
spring is more or less expanded, and the tension of the thread thereby regulated
according to desire.
I am aware that feeding mechanisms similar to the one described have been.
appplied heretofore in sewing machines, and these therefore I do not claim generally.
I am also aware that a spring has already been used in combination with the take-
up lever, and this consequently I neither consider as new; but I claim as my
Invention,-
1. In a sewing machine for elastics provided with the ordinary upper-feed motion,
the under feeding device consisting of a rotating shaft e, an eccentric g, a cloth
propeller i, and a slide h having the spring q¹, this feeding device being in combi-
nation with a smooth presser foot attached to the presser bar p of the upper feed
motion and with the cotter n, as and for the purpose described.
2. In combination with the take-up lever R, actuated by the needle bar and with
the spring u, the adjusting screw u¹, as specified and for the purpose set forth.
In witness whereof, I, the said Carl Pieper, have hereunto set my hand aud
seal, this First day of July, in the year of our Lord One thousand eight
hundred and seventy-eight.
CARL PIEPER. (L.S.)