Improvements in Overhead Sewing Machines.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improvements in Overhead Sewing Machines.
I JULIUS KOBLER of Limbach, Saxony, Manufacturer of sewing machines do hereby
declare the nature of my invention for IMPROVEMENTS IN OVERHEAD SEWING
MACHINES and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement and accompanying
drawings:—
My said invention relates to certain improvements in overhead sewing machines
and in order that my said invention may be more fully described and understood I
have annexed hereto a sheet of drawings to which reference will be hereinafter made.
In the said drawings the same letters in the different figures refer to corresponding
parts. One part of my said invention relates to a mode of supporting the feed dises
with the object of doing away with the disadvantages attending the present mode of
supporting the said feed discs.
Figure 1 is a sectional elevation of an overhead sewing machine and Fig. I is a
plan thereof with the cover-plate Z removed. In machines of this type the fabric to
be sewn is fed past the needle by a pair of feed dises a b. As is well understood the
back feed disc is caused to rotate by a suitable driving dise 2, and by means of a.
toothed wheel gearing into a corresponding toothed wheel f¹ on the axis of
the front feed disc 6 the latter is also caused to rotate. The front feed disc b
is sometimes supported by a lever capable of being raised or depressed by a
pedal to enable the front feed dise to be displaced in order to allow the fabric
to be introduced. This arrangement is subject to the disadvantage that where the
article to be sewn is bulky it cannot pass easily through the opening k, for which
reason the front feed roll is frequently suspended in a curved bracket or arm
the manner illustrated in Fig. 2. In this arrangement the feed disc rotates on a
stud carried by the bracket and to enable the fabric to be inserted the axis of the
back feed disc is connected with a lever on the depression of which the feed disc a
is moved backwards and assumes the position shewn in Fig. 2.
in
When making the overhead stitch (Fig. 3) the loop catcher is depressed in order
that the needle may enter the loop as is well understood, and as this depression takes
place close behind the projecting rim of the back feed disea the attendant can only
move the latter when the loop catcher is up; otherwise either the feed dise or the loop
catcher would suffer injury. This disadvantage of the last described arrangement
is not of much importance in the case of machines which are worked by hand or by
foot inasmuch as the machine can be readily stopped with the loop catcher in the
proper position, but in the case of machines driven by steam or other similar motive
power it is a serious drawback to obviate which I support the feed dises in such a
manner that while the back feed disea is fixed similarly to the arrangement shown in
Fig. 1 provide means for displacing the front feed dise for the purpose of
admitting the fabric to be sewn. Referring to Fig. 4 B is a curved bracket support-
in the front feed dise and provided with a plate A to which two bolts C C ure
attached. The bolls CC, which may be of any suitable section, slide in the body 1)
of the machine. The spring E acts in such a manner as to pull the bracket B
backwards or towards the machine thereby causing the front feed dise to press against
the back feed dise a. For removing the front feed disc from the back feed disc a I
employ a bell crank lever F F commerted to the sliding bolt C. By the use of the
above described arrangement of parts the motion of the front feed disc is rectilinear
and horizontal. Although two sliding bolts C C are shown this is merely a matter of
convenience; a single bolt of for instance a square section could be used.
modification of this part of my said invention is shown in Figs. 5 and 5 a of which
the former is an elevation parily in section and the latter a plan with the cover plate
removed. In this case the bracket B is rigidly secured to the body of the machine
en
A

page_text: and in its outer end a long stud is screwed on which fits loosely a hollow bush or
sleeve G provided with two projections G G the former carrying the front feed
dise and the latter being connected to a bar H which can be slid backwards and
forwards by means of a bell crank lever F F¹. When the end of the bell crank-
lever is pressed upwards in the direction of the arrow F the front feed disc 6 will be
withdrawn from the back one, and when the pressure on the bell crank lever is
removed. the resilience of the spring E will bring the feed disc ở back again to the
feed disc .
Another part of my said invention consists in the improved construction of the
loop catcher bar shown in detail in Figures 6, 6 and 66 and represented in its
proper position in the machine in Fig. 1. The said loop catcher bar is pivoted on
a pin passing through the hole »,. The front end of is slightly raised and contains a
slot in which the socket fits, so as to be capable of lateral adjustment by the
screw as shown in Fig. 6a. In the socket p is fitted the loop-catcher holder g
capable of being secured in the proper position by the set screws. The loop
catcher itself can be adjusted vertically in the head of the holder 7 and can be
secured where desired by the set screw q¹.
From the foregoing description it will be seen that the object of this part of my
invention is to enable the loop catcher to be adjusted either laterally, longitudinally
or vertically. When knitted fabrics are being sewn in an overhead sewing machine
it is not possible with the guides hitherto employed to feed the fabric forward to such
an extent as that the needle shall pass through the unrolled edge, and the object of
another part of my said invention is to apply a mesh holder to the feed discs. The
said mesh holder consists of a thin piece of steel or other suitable metal M,
Figs. and S. fitting on the inner surface of the feed dise a; at the right hand side
of the needle where the fabric is fed in the part M projects above and over the rim
of the feed disc as shown in section in Fig. 8. By this means the last row of meshes
is held up vertically between the part M and the needle block N' (Fig. 7) and is fed
in this position to the needle. The needle block N fits on a square or other suitably
shaped shoulder of the vertical shaft or stud carrying the feed dise and does not
partake of the rotation thereof. For regulating the height of the fabric passing
between the feed rolls there is usually employed a flat steel spring fastened to the
needle block N' by means of screws and the attendant regulates the height of the
fabric by bending the said spring upwards or downwards. In lieu thereof I employ
a projection P of the form shown in Figs. 7 and 9 provided with a heel at right
angles to the top part: a slot is further provided in the heel of the part P to permit
of vertical adjustment and through the said slot passes a set screw for the purpose of
securing the part P at any desired height.
My said invention also relates to the formation of the loop. Immediately the
needle draws back the thread as is well known must be held in some manner so that a
loop may be properly formed for the loop catcher to seize.
For this purpose al
lever R (Fig. 10) fitting in a groove in the needle bar has hitherto been used.
The
front end of the lever R is made to clamp the thread against the head of the needle
bar by means of a spring R. When this arrangement is used the thread always
passes at the same place between the end of the lever R and the head C¹ of the
needle bar wearing a groove therein until at last it becomes so deep that it is no
longer possible to clamp the thread.
According to this part of my said invention I employ the arrangement shown in
Figures and 11 consisting of a stud S with a head the said stud is free to rotate
and can also slide longitudinally in the head of the needle bar.
A spring T continually tends to pull the stud inwards and to cause the head thereof
to clamp the thread. A suitably shaped bar is bolted to the body of the machine.
The point of the stud S travels against the shaped edge of this bar and as the point
of the stud is pressed in or out by the configuration of the bar and the action of the
spring the thread is clamped or released. Owing to the stud being able to rotate the
thread does not wear in and no special provision need be made on the main shaft
of the machine for actuating the stud S.

page_text: 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. An overhead sewing machine having in combination with the usual parts of
such a machine the bereinbefore described arrangements of mechanism for supporting
and displacing the suspended feed disc b, the loop catcher bar with the means of
adjustment as described, the mesh holder m projecting above and over the rim of the
back feed roll, the height regulator and the clamping stud S governed by the
configuration of the edge of the bar C substantially as herein before described and
shown.
2. A sliding bracket B (Fig. 4) supporting the front feed dise at one end and
provided at the other end with one or more bolts for the purpose of sliding the front
feed disc horizontally in and out of contact with the fixed back feed disc a
substantially as and for the purpose hereinbefore described and shown.
3. A fixed bracket B (Fig. 5) having a support working on a stud at its outer end
for the purpose of carrying the front feed dise and provided with means for causing
the said feed dise to move in and out of contact with the other feed disc in a
curved horizontal path substantially as herein before described and shown.
4. A loop catcher bar with the means for vertical, lateral, and longitudinal adjust-
ment substantially as hereinbefore described and shown in Figures 6, 67 and 66.
5. A mesh holder M projecting above and over the rim of the feed dise substantially
as and for the purpose hereinbefore described and shown,
6. A projection P vertically adjustable on and secured to the needle block for the
purpose of regulating the height of the fabric passing between the feed dises
substantially as hereinbefore described and shown.
7. A clamping arrangement for the needle thread consisting of a headed stud
mounted so that it can turn and slide in the needle bar in combination with a fixed
bar the configuration of which regulates the action of the clamping stud sub-
stantially as hereinbefore described and shown.
Dated this Thirteenth day of August, 1889.
JULIUS ALLMANN & Co..
70, Deansgate, Manchester, Agents for the Applicant.