Improved Feed Mechanism for Sewing Machines.
Year: 1898

page_text: Date of Application, 15th Feb., 1898-Accepted, 18th June, 1898
COMPLETE SPECIFICATION.
Improved Feed Mechanism for Sewing Machines.
I, WENZEL HLAVACEK, of No. 64, Thal Strasse Meissen, in the Kingdom of
Saxony, Mechanician, 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:-
In the construction of double quilting stitch sewing machines much effort has
been devoted of late to obtain an arrangement of the mechanism in such a
manner that the machine is rendered capable of sewing both forwards and back-
wards. In order to attain this result a reversing mechanism must be provided
which forms the operative part for the reversing motion of the feed mechanism.
Almost all reversing mechanisms devised for this object hitherto have however
not reached the position of practical use. Those few mechanisms which have
hitherto been brought upon the market still possess very great drawbacks, in
that they (firstly) cannot be operated suddenly during the most rapid speed of
the machine without thereby interrupting and damaging the other mechanisms
in their work, and (secondly) because their construction renders necessary very
considerable deviations from the established construction of the other parts of
the sewing machine.
The object of the present invention is a reversing feed mechanism adapted to
such double quilting stitch sewing machines which have a feed mechanism of
the "Singer" type. The above mentioned drawbacks are avoided in this new
construction.
The characteristic distinction of the present invention consists in that at any
convenient point, by the actuation of a correspondingly constructed drawbar,
the fulcrum of a reversing lever inserted in the feed mechanism can be removed
over its point of engagement. In consequence of this, the said lever can act at one
time as a one-armed lever, and at another time as a double armed lever, and
will in consequence act upon the feeder in opposite directions.
Referring to the accompanying drawing in which three modifications of the
invention are illustrated by way of example:-
Figure 1 shews the simplest modification in the normal position.
Figure 2 shews the same in the reverse position.
Figure 3 shews a longitudinal section on the line, Figure 1.
Figures 4 and 5 and Figures 7 and 8 shew respectively two other modifications
in the normal position and in the reverse position.
Figures 6, 9, and 10 shew details of the mechanism.
In the construction shewn in Figures 1 to 3, the lever A which moves the feeder
is divided into two parts A, A¹ which are pivotally connected with one another
by means of the reversing lever H above mentioned with its adjustable fulcrum.
The part A, movable as usual by means of an eccentric E, is supported at its
other end in a guide F secured to the bed plate and attached to H by means of
the pin g. The one end of H is connected to A¹ by means of the pin g¹, the other
somewhat broader end e is supported and guided whilst the apparatus is in the

page_text: normal position as shewn in Figure 1 by means of the piece S in the U-shaped or
slotted end of the arm S¹.
Between the two pins g g¹ the piece H is correspondingly widened at e¹. In
the position shewn in Figure 1 the fulcrum of the connecting lever H is its end e
supported adjustably in S. As the same in this position comes to lie outside
the two pivots g g¹, the lever H acts as a one-armed lever at g' upon A¹, and
nioves the said part A exactly as it would be moved if it formed as usual a single
piece with A, because H is compelled by the pivot g to share the motion of the
part A in the same direction. The feed mechanism consequently when in this
position pushes the material forwards in the usual manner. If, however, the
picce S be displaced to the left by means of a pedal or a handle accessible to
the operator, the end e ceases' to be the fulcrum of the lever H, and this service
is taken by the part el. As, however, e lies between the points g and g¹, the
piece H now operates as a two armed lever, and it consequently moves the lever A¹
which is supported as usual in the stitch adjusting joint G in the opposite
direction, because must follow the motion of A in like manner as before. The
raising and lowering of the feeder is not hereby affected, because it can be pèr-
formed as usual by means of the projection on the lever A¹. The piece S as
well as its guide piece can of course be constructed in various forms, and it is
only essential that the length of the track which S¹ has to make upon the reversal
should be equal to the distance from the point e to the point e¹.
In this con-
struction, moreover, the parts S S and Hand the respective guide pieces are
the only novel portions of the mechanism.
It will be clear from this description than any ordinary double quilting stitch
machine, the feeder of which corresponds to the "Singer" type, can be provided
without much difficulty, and at a slight cost with the reversing mechanism. In
*his advantage, as well as in the noiseless operation of this reversing mechanism,
which, moreover, cannot influence injuriously the action of the machine even at
the quickest speed, the great practical value of this machine may be easily
recognised. It should however be remarked that the parts above described caus-
ing this new technical effect should not be attached directly at the place shewn
in the Figures 1 to 3, but preferably be placed immediately before or behind the
presser foot T, and act upon it directly or indirectly.
ד י'
Figures 4 to 10 illustrate two examples of the construction in this manner,
which render necessary slight alterations in the shape of the presser foot T and
of the lever A.
In the construction according to Figures 4 and 5 the presser foot T is prefer-
ably shaped as shewn in Figure 6. Through the slot i is inserted the end of the
lever A which is connected with H by means of the pivot g and correspondingly
lengthened. This part is not visible in Figures 4 and 5. The width of the slot i
corresponds to the thickness of the lever A, in order that the part T may always
follow the up and down motion of A caused by the projection, whilst it. is not
dependent upon the two and fro motion of the lever A, because this latter motion
is conveyed to it indirectly through the lever H, the end g₁ of which is connected
pivotally with a guide piece b, which piece slides in the suitably shaped end c
of a guide lever C revolving upon the fixed pivot el. The slide c is inserted in
a hollow a of the piece T, the length of which corresponds to the width e, conse-
quently will receive a two and fro motion by aid of the part of the lever, H,
(which itself receives the motion by means of the pivot g from A,) and thereby
causes the foot T to share the same. It results from this that the depth of the
hollow a must correspond to the height of the projection of the feed mechanism,
because the lever C does not share in the rising and falling of the lever A. In
like manner the length of the slot i must correspond to the greatest length of
the stitch because A must not hinder in any way the two and fro motion of the
piece T. The part S is of course correspondingly prolonged, and the arm Si
is so attached thereto, that T is not hindered thereby in its motion. The spring D

page_text: pressing against the part S prevents an automatic springing back of the piece S
in case its guides have become somewhat worn. The feeder spring d can in
this case be done away with, because the piece T finds a resistance at every speed.
The method of operating is precisely the same in this modification as in that
previously described.
In the normal position (Figure 4) the piece H acts as a one armed lever, and
moves the material forwards. In the other position shewn in Figure 5 H acts
as a two armed lever and moves the material backwards. In the above described
cases, the lever H is not adjustable, and its connecting points are pivot-bolts,
whereas its fulcra rest adjustably in fixed bearings St. The arrangement can
obviously also be reversed as is shewn by Figures 7 to 10. In this case the
lever H possesses only one fulcrum constructed as a pivot e and is therefore moved
together with the part S, so that in the normal position, as shewn in Figure 7,
the point e lies outside the attaching point, whereas in the other position shewn
in Figure 8 it lies inside the said point. In order to obtain this effect it is of
course necessary to cause the presser foot to share in the two and fro motion of
the lever A in an indirect manner, for which purpose there is secured besides
the guide n of the feed mechanism T a second guide m fixed on the bed plate,
and in this latter a sliding piece q is placed, shewn in Figure 9 in side view.
This sliding piece is constructed with a cavity k in which the end of the lever A
engages, and another cavity in which the lever H engages. The presser
foot T (Figure 10 in side view) possesses a cavity which also engages the
widened part of H and a step y with which it rests upon A. The up and down
motion will consequently be transmitted to T in this manner from A, and the
two and fro motion by aid of the sliding piece q and reversing lever H. It is
advisable to cut out somewhat the lever A at the point where it makes contact
with T so that even at the greatest length of stitch the feeder will not be hindered
in its to and fro motion. As in this case the arrangement of a second sliding
piece q becomes necessary, the lever C (Figure 4) may be done away with, if the
piece S and the piece H are constructed in the manner shewn in Figures 7 and 8.
In this construction the piece H simply rests with its whole under surface upon the
upper surface of S, and is connected with S by means of the bolts e, the heads
of which are preferably countersunk. In this construction the sliding arm S
of the piece S is done away with. In this case, moreover, the lever H possesses
three engaging points g g and g2 of which g and gl act in the normal position
shewn in Figure 7, and g¹ and g² act in the other position shewn in Figure 8.
The method of operating is the same as with the modifications previously
described.
The above described three modifications are only intended to serve as examples
of the invention set forth in this application. All other possible modifications are
claimed as within the scope of this patent, if they possess the characteristics set
forth in the following claim. Thus for instance the sliding arm S might be
constructed like the part G or the lever H might be formed as a slide throughout
its whole length, in which slide a revoluble piece attached to S¹ would engage
and so forth.
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:-
The improved reversing feed mechanism for sewing machines, having feeders
of the "Singer" type characterized by the arrangement that at any suitable
point of the same a reversing lever H interposed in the feed mechanism is so
arranged that its fulcrum (e or e) is adjustable by means of a sliding piece S
or S¹ either outside of both its connecting points g g or g² or between the same
at will, so that during the quickest motion of the machine the same is capable of
being noiselessly adjusted without interfering with the other moving parts, in

page_text: such a manner that it can either act as a one-armed or as a two-armed lever, and
thus convey the two and fro motion imparted to it by the eccentric rod A. either
directly or indirectly to the feed mechanism, also directly or indirectly, substan-
tially as described.
A
1000
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.