Improvements in Sewing Machines.
Year: 1892

page_text: Date of Application, 11th Mar., 1892
Complete Specification Left, 12th Dec., 1892-Accepted, 11th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in Sewing Machines.
I, CARL RICHARD MÜNCH, Mechanical Engineer, of 36, Sophienstrasse, Leipzig,
in the Kingdom of Saxony, do hereby declare the nature of this invention to be
as follows:-
This invention relates more particularly to double lock stitch sewing machines,
the principal features of novelty being a special manner or means of holding
the shuttle, and the arrangement of the bobbin holder in the interior of the
shuttle.
The shuttle is of the revolving circular type, placed horizontally and supported
at its circumference by a divided ring. The bobbin holder or casing is placed in
the vertical axis of the shuttle and stationary.
The cloth feeder is a double armed vertical lever secured to the side of the
column or stand which contains and supports the shuttle, the upper arm of the
lever being serrated to serve as cloth feeder, while the lower and shorter arm
has a rectangular foot or end piece, which is in contact with a pair of cams
mounted on the horizontal driving shaft and acting on two contact faces of the
said foot. As the said cams turn on their axis, the said lever is lifted and at the
same time turned on its fulcrum, the latter being formed by a horizontal stud
mounted on a vertical plate adapted to slide up and down between a pair of
vertical guide cheeks.
A special thread guide and tension apparatus is employed, in order to impart to
the thread the necessary tension, without removal of the shuttle bobbin. This
apparatus comprises a radial arm or cover plate placed at the open top of the
shuttle and extending radially from its centre to the circumference of the same,
the said arm being provided near the inner end with a vertical stud or pivot which
is guided in an axial socket of the shuttle pivot, while the outer end of the said
cover plate is provided with a plate or strip extending downward parallel to the
axis of the shuttle. The said vertical strip is slotted horizontally, both at the top
and near the middle of its height, the two slots extending from opposite edges of
the strip (right and left) to the middle of its width.
The radial arm or cover plate has a vertical perforation immediately outside the
vertical strip, and an oblique slot extending from the said perforation to the right
or left edge of the same, so that the mouth of the slot is nearer to the shuttle axis
than the vertical perforation.
The top of the radial cover plate has a radial groove, in which is placed a flat
spring secured at or near the axis (of the bobbin and shuttle) by means of a vertical
set screw with slotted head, which can be turned and thereby the screw tightened,
without touching any other parts. The thread is conducted through the slot into
the vertical perforation of the cover plate (which passes over the shuttle bobbin)
and thence led off underneath the flat tension spring (between the latter and the
cover plate).
Dated this 10th day of March 1892.
FAIRFAX & WETTER,
Agents for the Applicant.

page_text: cavity d, always carried around free and unimpeded, without any risk of friction
and stoppage, and the loop is then drawn in or dissolved.
This is effected by the well known thread lever, situated on the side of the sewing
machine shead and set in motion by a cam, so as to draw up the thread at the
moment when the shuttle has thrown off the thread, and after the needle has
emerged from the fabric.
For correctly introducing or guiding the needle during its down motion, the
ring D is provided with a corresponding recess e, Fig. 10, and with a pair of
small cavities m, which has the object of safely. guiding the thread g the right
way, Figs. 10 and 17.
In order to fix the bobbin of the shuttle thread, the bobbin holder H is provided
with a raised part for guiding the thread, on which rests a removeable bridge k,
the ends of which are journaled in the shuttle holder B.
The bobbin holder H is held fast by means of its projection h (Figs. 14 and 15),
over which extends the bridge & (Figs. 9 and 10), and the bobbin is held by a
bridge'n,
likewise removeable.
The bobbin holder H contains a device for regulating the tension of the thread,
Figs. 13-16.
!
Acting in conjunction with the shuttle A, there is a cloth feeder S, which
receives its oscillating up and down motion in a special manner, as represented by
Figs. 2, 3, 6 and 7.
The cloth feeder consists of a lever S, which is pivotted to the sliding guide
block p carrying the pivots, and at its bottom end R it is provided with two sliding
surfaces and placed at right angles to each other. The contact faces are
acted upon by two cams C1 and C2, so that the upward motion of the lever S and
slide P is caused by the cam C', while the cam C2 through the contact face r²
produces the turning of the cloth feeding lever S on the pivot s.
In order to produce or ensure the backward and downward motion of the cloth
feeder, a spring fis employed, which acts on the corner of the foot piece R, and
thus works sideways, as well as downwards.
In order that the shuttle bobbin t may be as large as possible, and to effect the
threading of the shuttle thread and its tension, without being obliged to take the
shuttle apart, and also to produce the tension of the thread in such a manner, that
the working condition (ready for sewing) of the machine need not be interrupted
and the shuttle need not be taken out of its seat, the holder H of the bobbin is
dispensed with, and the mechanism for threading and tightening is placed on the
bobbin and the shuttle from the top, in consequence of which the mechanism is
given the following arrangement; The bobbin holder H is replaced by a plate E.
The plate E carries the pin l, by which it is mounted on the bored out spindle
of the shuttle A, Fig. 19, and it carries besides the plate projecting downwards
between the shuttle and the bobbin. The plate is provided with slots "and",
Figs. 24 and 27-29, of which reaches underneath the thread hole in the
plate E; the thread hole is rendered accessible by the slot from the edge
of the plate. The aperture for the thread is covered by a spring 9, which is
adjustable, so as to exert any desired pressure against the thread hole, by means of
a screw, and is situated in a groove of the plate E. This thread guide and
tension mechanism come into operation in the following way; After the bobbin t
has been placed on the shuttle spindle in the interior of the shuttle A, which may
be completely filled up by the same, the plate E is introduced with its pivot into
the socket of the shuttle spindle, so that it covers the bobbin and shuttle, and the
plate reaches over the outer edge of the bobbin, the shuttle thread having been
previously conducted from the slot 1, Figs. 28 and 29, to the slot 1, and by being
tightened, drawn through this and the slot and caused to pass under the spring q,
into the aperture l, and drawn out from under this spring at the front edge of the
plate E, whereby the threading is completed. The plate E is held in position by a
recess F in the stitch plate F, Figs. 19, 22, and 23, with so much clearance, that the
loop of the thread, Fig. 21, when being drawn off, may pass between the stitchplate F

page_text: and the plate E. The tightening of the thread also is evidently very simple, the
change of tension being capable of regulation at any time by the exposed screw g¹.
In this arrangement, the means of guiding and tightening the thread offer the
advantage, that a maximum size of bobbin may be employed, also that for intro-
ducing the thread it is only necessary to take out the thread guide E, and for
tightening, only to move the exposed screw q', and that consequently these mani-
pulations may be effected in the simplest and most reliable manner.
A sewing machine provided with the hereinbefore specified arrangement, works
with unusual ease and certainty, as a stopping or jamming of the thread or cutting
or tearing of the same is almost impossible.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A double lock stitch sewing machine, comprising in its construction a hori-
zontal revolving shuttle A, held at its sides by a divided ring D, and having in its
interior a stationary bobbin holder H, the shuttle holder B of the machine carrying
also a cloth feeder S, which receives its up and down and its oscillating motion
through cams C¹ C2 made in one piece, and a foot piece R provided with
contacts, in such a way, that the slide block p moves up and down, and with
it the feed lever S, which also oscillates on the pivot s, substantially as specified
and shown in the drawings.
2. In the shuttle arrangement specified by Claim 1, the construction of the thread
guide and tightening mechanism from a plate E, which is guided in the shuttle
spindle by the pin land covers the bobbin t and the shuttle A, and in this position
allows the introduction of the shuttle thread into the aperture 1, by means of the
plate having slots, and a slot, the said thread being then carried
under the spring q, which, by means of its exposed tightening screw q', may be
caused at any time without touching any other parts to press on the thread more or
less, according to requirements, the whole substantially as described and for the
purpose specified.
Dated this 10th dow of March 1802
FAIRFAX & WETTER,
433, Strand, London, Agents.