An Automatic Thread Regulator for Sewing Machines.
Year: 1888

page_text: Date of Application, 14th Jan., 1888
Specification Accepted, 17th Feb., 1888
An Automatic Thread Regulator for Sewing Machines.
I ERNST BÖTTCHER of 59 Stallschreiberstrasse, Berlin in the Empire of Germany,
Sewing Machine Manufacturer 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 relates to an automatic thread regulator or tension apparatus applicable
to all kinds of Sewing Machines, such thread regulator being so connected with
the presser foot bar, that it partakes of every movement of the same, and gives off to
the sewing instruments such an amount of thread as exactly corresponds with the
thickness of the material underneath the presser foot, and as is necessary for the
secure tightening of the stitches, without any breakage of the thread occurring.
In the accompanying Drawings is represented the automatic thread supply
mechanism or thread regulator, adapted to a sewing machine for sewing over the
edge of the work.
Fig. 1 shews the machine in side view.
Fig. 2 in back view, and
Fig. 3 in front view.
Fig. 4 is a sectional elevation of the head of the machine, the section being taken
on the line y of Fig. 1.
Fig. 5 is a plan view of the machine; the other Figures are details.
Upon the main driving shaft a, which is provided with a driving pulley a', is
arranged an excentric a³, which, by means of a rod f (Figs. 1 and 2) and an arm g,
transmits a rocking motion to a shaft h. This shaft h, by means of a second arm gi
and a link g², imparts the requisite reciprocating motions to the needle bar i. Near the
needle bar i is arranged, so as to be capable of an up and down motion, the presser
bark. This bar carries a clamp 2 (Figs. 3 and 4), to which is rigidly fixed an arm k³.
This arm carries a pin k*, which takes into the slot of an arm k³ keyed to a shaft ko,
which is mounted below, and parallel with, the rock shaft h on the bracket arm.
shaft carries, at its rear end, the thread regulator 7 (Figs. 1 and 2), which passes
completely through a slot in the bracket arm A of the framing of the machine, and
is provided, at its free end, with an eye through which the thread will be drawn. The
aring (of the shaft h), which stands adjacent to the thread regulator k³, is provided on
This

page_text: its upper edge with an adjustable screw tappet g*, which, when the arm g is at its
highest position, comes into contact with the centre pin which carries the upper disc
of the thread tension arrangement o (Fig. 2), and lifts that disc at every rocking of
the shaft h. This raising of the upper disc allows the thread held by the thread
regulator to pass freely through the tension apparatus. In addition to this, the arm g
is furnished with a hook-shaped extension 93, which is provided with a hole through
which the thread passes. The thread coming from the bobbin m (Figs. 1 and 2),
passes through a fixed guide eye m¹ on the bracket arm, between the ordinary tension
discs n, then through the eye of the thread regulator k' and the eye in the extension g³
of the arm g, then upwards between the discs of the automatic thread tension device o,
and thence through the fixed guide eye p carried by the bracket arm.
From this eye,
the thread passes to a spring slip q (Fig. 3) fitted to the head of the machine, thence
through fixed guide eye r, and so to the needle.
The presser, in the case here represented, will, by means of a spiral spring k",
arranged within a recess in the step A¹ of the head of the sewing machine, always
have a downward tendency. The said spring presses upon a rod ko, also arranged
within this recess, into which rod is screwed a pin k³, which passes through the presser
bar. This pin 48 carries at its front end a cam k provided with a handle, the said
cam pressing, with its periphery, against the part A2 of the sewing machine head.
On turning the cam by hand, the presser bar will be raised.
The operation of the thread regulator k is as follows:-
On turning the shaft a, the excentric a2 will, through its rod f, impart a rocking
motion to the arm g of the shaft h. If, now, the thread were not passed through the
eye of the thread regulator k, the arm g (in other words, its extension g³), in every
downward motion thereof, would always draw off the same amount of thread from
between the tension discs n, and, on its next upward movement, pass on this amount
of thread to the sewing instruments, the automatic tension o being meanwhile slackened.
In consequence of the same amount of thread being always delivered to the sewing
instruments, it would follow, that only material of a certain thickness could be
properly sewn, or such as will take up the thread drawn off at each time for the
formation of a stitch.
If, now, on the other hand, the thread is drawn through the eye of the thread regu-
lator k², as represented in the Drawing (which, instead of being provided with the eye,
might be bent into a hook shape at its end, in which case the thread lies under the
hoop), the sewing instruments will receive the necessary amount of thread, regulated
by the thickness of the material to be sewn.
As already mentioned, the thread regulator k is so connected with the presser
bar k, that the former must rise and fall with the latter. If, now, a material of any
desired thickness, to be sewn, is laid upon the sewing plate D (Fig. 3), underneath
the presser foot k¹, and the thread regulator k is so placed upon the shaft 48 (upon
which it is adjustably secured by means of the screw k¹², Fig. 2), that the eye k
stands at such a height above the lowest point reached by the eye in the arm extension g³,
that the distance between the eye in k and the one in g³ is equal to the length of
thread required to form a stitch, then the thread regulator is properly adjusted, in
order, without further trouble, to deliver exactly the necessary length of thread for
every thickness of work. For, when a thinner material is employed, the presser
falls, and with it the thread regulator k', whereby the distance between the eyes in k
and in g is diminished, whilst in the case of a thicker material, the presser rises, and
with it the thread regulator k', whereby the distance between the eyes in k' and in g³
is increased.
Figs. 6 and 7 shew in diagram the position of the presser k and of the thread
regulator k, both in the case of a thin and of a thick material; whilst Figs. 8 and 9
show the positions of 7 and 93 in the case of thin and thick materials. The length
of the thread shewn in the two latter Figures between the eye in k' and the eye in g³,
is the amount of thread required for the particular stitch in question, and will, on the
upward movement of the arm g with its extension 93, become slack, and slip, at the
end of the upward movement of the arm g, through the slackened tension device o.

page_text: By means of the described connection of the thread regulator with the presser k,
a breakage of the thread is rendered impossible, because the thread regulator itself
accompanies the movement of the presser, and only allows so much thread to pass
through the tension device o, as will be loose between k and g³ upon the upward
movement of the arm g.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, 1 declare that what
I claim is
A thread regulator for sewing machines constructed and operating as above set
forth, such thread regulator being so controlled in its action by the rise and fall of
the presser, as to impart to the sewing instruments that amount only of thread which
is necessary for a firm tightening of the stitch in varying thicknesses of work, without
risk of breakage of the thread.
NEWTON & SON,
Agents for the Applicant.