Improved Feed Motion for Overhead Sewing Machines.
Year: 1889

page_text: Date of Application, 27th July, 1889-Accepted, 7th Sept.,
1889
COMPLETE SPECIFICATION
Improved Feed Motion for Overhead Sewing Machines.
"
'I JULIUS KOHLER of Limbach, Saxony, Manufacturer of Sewing Machines, do
bereby declare the nature of my invention for "Improved feed MOTION FOR OVERHEAD
SEWING MACHINES and in what manner the same is to bo. performed to be particularly
described and ascertained in and by the following statement and accompanying
drawings: :-
My said invention relates to an improved method of intermittently rotating the
feed discs of overhead sewing machines and in order that my said invention may be
more fully understood I will at once proceed to describe the same with reference to
the accompanying sheet of drawings in all the figures of which the same letters refer
to corresponding parts.
Fig. 1 is a sectional elevation of so much of an overhead sewing machine as is
necessary to show the object of my said invention. In such machines there is a
horizontally moving needle c and underneath the said needle are two feed dises a
and b between which the fabric to be sewn is fed past the needle by the intermittent
rotation of the feed dises a b. The feed disc a derives its motion from the vertical
shaft driving the feed disc b in the usual manner as is well understood.
When operating on knitted fabrics 15 of importance that the intermittent forward
progress of the materials shall correspond to the distance of the meshes from each
other to enable them to be stitched mesh by mesh. This is of particular importance
in the case of shaped goods which are knitted to the desired form and have a perfect
edge or selvage. In order to accomplish this I cause the intermittent rotation of the
feed disc 6 to be effected in such a manner that the extent of the intermittent move-
ments is under control and can be adjusted to the pitch or distance of the meshes
from each other.
Fig 3 of the accompanying sheet of drawings is a vertical section of the device I
employ for carrying my said invention into effect. Fig. 4 is a plan of the same.
Fig. 5 is a front elevation thereof and in Fig. 6 are shown detached parts of the
mechanism I use for effecting the rotation of the feed discs Fig. 2 is a plan as seen
from below showing how the device illustrated in Figures 4, 5, and 6 is applied to an
overhead sewing machine.
To the upper end of a vertical shaft e is secured the feed disc b and to the lower
end of the said vertical shaft is fastened a block d in the plane faces of which are
formed annular recesses, each of which receives a dog g, g' the said dogs being
secured to the carriers h h².
The upper carrier les loosely on the face of the block d being held in position
by a collar e¹ while the lower carrier his held loosely against the bottom face of the
block d by means of a cover plate e. A spiral spring (Fig. 4) attached to one end
of the carrier h exercises a continual pull in the direction of the arrow A. The other
end of the spring is connected to a bracket lying in an annular groove in the
cylindrical surface of the block d and pivotted at k on the carrier h so as to follow
the movements thereof. The spring is thus not stretched by every movement of the
carrier but merely serves to continually bring the dog 9 into position for bearing
against the vertical faces of the annular recess f
If by suitable mechanism such as for instance an arrangement of lovers actuated by
an excentric or cam the back end, viz. :-that end of the carrier h to which the
bracket is pivoted, is moved in the direction of the arrow B the dog g will bind
against the vertical faces of the annular recess and the block d will be rotated in the
direction indicated by the arrow E. The greater the force acting on the carrier h
the more firmly will the dog g bind against the sides of the annular recess f. Lf
subsequently the direction of motion of the back end of the carrier his reversed so as

page_text: to correspond to-that-of the arrow-C the dog g-will assuine-the-position represented
by the dotted centre line mn and will free itself. The resilience of the spring h³
will pull the front end of the carrier in the direction of the arrow A until the
dog is again caused to bind. The extent of the movement of the dog g which
is controlled by the distance which the carrier is moved at each stroko regulates
the amount of rotation which the block a receives at each movement of the carrier h
and thus -determines the distance the material to be sewn is fed forward for each
stitch. Since the bracket is attachen at k to the carrier has herein before described
it also partakes of the movement in the direction of the arrow A and the spring *
is therefore not stretched by such movement
In order to prevent the retrogression of the block d on the backward stroke of
the carrier or by the drag of the fabric which is being sown thero is provided on
the under face of the block d--a corresponding carrier ', also provided with a dog gl
h³ and a bracket acting together in a similar manner to the parts indicated
by the same letters but with different indices connected with the upper cariter h.
One end of the botton carrier is provided with a slot through which passes a
bolt screwed to the body of the machine.
a spring
Should the block d have any tendency to a retrograde movement in the direction
of the arrow 1) the dog g' will bind against the vertical sides of the annular
rocess and prevent any backward rotation of the block d.
On the forward movement of the block that is to say in the direction indicated
by the arrow E the dog g¹ frees itself so as to allow the block d to be advanced by
the forward movement of the dog g.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1. The use combination and arrangement of parts constituting a device for
intermittently driving the feed discs of overhead sewing machines substantially
herein before described and shown.
2. The use combination and arrangement of the carriers h h provided with dogs g g'
binding on the faces of annular recesses formed in a block d for the purpose of
imparting to the discs of an overhead sewing machine an intermittent notation corre-
sponding in extent to that of the lateral movement of the carrier h the whole acting
substantially as herein before described and shown.
3. The carriers ' acting in combination with the brackets i 1 carrying the
springs h² h³ substantially as and for the purpose herembefore described and
shown.
Dated this The
1000
-
JULIUS ALLMANN & Co.,
70, Deansgate, Manchester, Agents for the Applicant.