Year: 1892

page_text: Date of Application, 12th Apr., 1892
Complete Specification Left, 7th June, 1892-Accepted, 12th May, 1893
1, GUSTAV LANGENBERGER, of 44 Fischersand, Erfurth, Germany, Mechanician,
do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in lockstitch sewing machines in which
the underthread is drawn from an ordinary thread reel that is to say in which
there is employed in place of a shuttle, a reel which is enclosed in a reel carrier.
In the accompanying drawings,
Fig. 1 is a longitudinal section of so much of a lockstitch sewing machine as is
necessary to illustrate this invention and
Fig. 2 is a plan of the same.
Fig. 3 a cross section on the line A A Fig. 1, and
Fig. 4 a cross section on the line B B Fig. 1.
Figs. 5 to 31 inclusive illustrate the formation of the stitch and the seam
produced by a sewing machine constructed according to this invention and will be
hereinafter referred to.
The under thread reel a which is of the ordinary commercial size, is surrounded
by a reel carrier b of flat wire or sheet metal bent to the form shewn in Fig. 1,
which engages by means of pins or projections c with and holds the reel, and is
provided at top with a number of holes, d for adjusting the tension of the under
thread. This reel carrier which also acts as a tension device is held between two
knobs which are moved to and fro simultaneously in a uniform manner,
and so
move the reel carrier and the under thread reel to and fro.
P
fis a rotating looper which is of drum form and is provided with a looper
hook. The hook projects to a slight extent beyond the circumference of the
looper and has for object to spread the under thread into the form of a loop.
The looper is actuated, by suitable means, such as a toothed wheel 9 mounted
on it, in such a manner that the hook f¹ will, when in a suitable position, engage
with the under thread, spread it, and then, after the under thread reel a with the
reel carrier b has passed through the loop, will release the same. The looper fis
hollow and is capable of containing the reel a together with the reel carrier b.
The prolongation of the hollow of the looper f forms a wide casing h in which the
reel carrier b and reel a can move to and fro.
The needle of the sewing machine operates in combination with the looper
hook and the under thread reel a as follows:-
In Figs. 5, 6 and 7 which show parts in the initial position and the under thread
reel a on the right entirely within the looper f, and the needle in its highest
position. The upper thread is marked k, and the under thread is marked 1. The
looper hook is assuming its highest position after throwing off the previously
looped upper thread. Then the machine being in motion the reel carrier 6 with
the under thread reel a will move towards the left into the casing h, whilst the
looper hook f¹ will remain at rest. This second position is shewn in Figs. 8, 9
and 10, the needle having reached its lowermost position, whilst the movement of
the under thread reel a towards the left is not yet finished.
Upon the further movement of the under thread reel a into its extreme left hand
position shewn in Figs. 11, 12 and 13, the looper f with hook f¹ will move towards
the needle through approximately 60 degrees whilst the needle eye will remain at
The needle will still remain at rest while the looper will move further
towards the left into the fourth position (Figs. 14 and 15), sliding with its hook fi
past the rear side of the needle, thereby engaging with the upwardly moving upper
rest.

page_text: thread k, which passes at its upper end through the material, having formed the
preceding stitch, and at its lower end through the eye of the needle.
The needle will then move upward into the 5th position shewn in Figs. 16, 17,
and 18, and the looper hook f¹ will move into its lowermost position, and engage
with the upper thread k fed by the thread-feeding device and spread the same
into the form of a loop, one side of which will move across the front of the
looper, and the other side of which will enter the approximately semicircular
groove m in the looper f.
The under thread reel a with the reel carrier will then begin to move into the
right hand position, Figs. 19, 20, and 21 (the 6th position), whilst the looper
hook will still further spread the loop of the upper thread k, so that one side of
this loop can pass between the reel carrier 6 and the right hand knob e. When the
looper, by further rotation, assumes the position shewn in Figs. 22, 23 and 24, the
looper hook will stop, after the upper thread k has been spread to form a complete
loop. The under thread reel a, together with its reel carrier device will then
pass through this loop, which lies in the groove m on the circumference of the
looper. The groove m terminates at the edge of the looper fat a point n
approximately diametrically opposite the looper hook f¹, as shewn in the several
figures.
When now the under thread reel a has passed completely through the loop of
the upper thread k, as shewn in Figs. 25-27, in the 8th position, the looper with
its looper hook f¹ will commence its final movement into the position shewn in
Fig. 9, or Figs. 5-7, whereby the end n of the annular groove m will be caused
to rotate further to the right, so that the loop of the upper thread k can fall off,
which is then automatically drawn up by a thread tension device, the under thread
being engaged by the loop and drawn tight.
The 9th or final position is shewn in Figs. 28, 29 and 30, and corresponds to the
initial position (Figs. 5-7). The under thread has been passed through the
loop of the upper thread, so that the under thread is thereby connected with
the upper thread by means of a flat open loop, in the manner shewn in Fig. 31.
Fig. 31 shows also the manner of the formation of a loop of this kind by means of
the downwardly carried upper thread k and the under thread 1.
Dated this 12th dev of Anril 1809
G. LANGENBERGER,
By L. W., per F. B.
COMPLETE SPECIFICATION.
Improvements in Lockstitch Sewing Machines.
I, GUSTAV LANGENBERGER, of 44 Fischersand, Erfurth, Germany, 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 :-
This invention relates to improvements in lock stitch sewing machines of the
kind in which the underthread is drawn from an ordinary thread reel, that is to
say in which there is employed in place of a shuttle, a reel which is enclosed in a
reel carrier, and it has for object to simplify the construction of such machines.
In the accompanying drawings,
Fig. 1 is an underside view of a lock stitch sewing machine showing the reel
carrier and looper and the mechanism for operating the same according to this
invention.
and
Fig. 2 is a longitudinal section on the line A B Fig. 1.
Figs. 3 and 4 are cross sections on the lines E F and G H respectively of Fig. 1;
Fig. 5 is a longitudinal section on the line C D of Fig. 1.
Figs. 6 to 20 inclusive which are drawn to a larger scale than Figs. 1 to 5

page_text: inclusive illustrate the formation of the stitch, and Fig. 21 the stitches made by the
machine, and will be hereinafter more particularly referred to.
The underthread reel a, which is of the ordinary commercial size, is surrounded
by a reel carrier b of flat wire or sheet metal that is bent to the form shown in
Fig. 1, and is adapted by means of pins or projections e to engage with and hold the
reel, and is provided at the top with a number of holes d for adjusting the tension
of the underthread. This reel carrier which thus also acts as a tension device, is
held between two knobs e which are moved simultaneously to and fro in a uniform
manner, and consequently move the reel carrier and the under thread reel to
and fro.
is a rotary looper of drum form provided with a looper or hook f. This hook f
projects to a slight extent beyond the circumference of the looper and has for object
to spread the upper thread into the form of a loop.
The
The looper drum f is actuated by suitable means, such as a toothed wheel
mounted on it, in such a manner that the hook f¹ will, when in a suitable position,
engage with the upper thread, spread it, and then, after the under thread reel a
with the reel carrier has passed through the loop, will release the same.
looper drum fis capable of receiving the reel a together with the reel carrier b.
h is a casing arranged in line with the hollow looper f and in which the reel
carrier b and the reel a can move to and fro. The knobs e e, which move the reel
to and fro, and the looper drum fare in the example shown operated by a recipro-
cating plate A that is mounted to slide in suitable guides B B and is actuated from
a crank disc C through the medium of a connecting rod D. The plate A is
constructed with two slots E and F of special form and inclination and into which
extend rollers G and H respectively. The roller G is mounted on a pin attached
to a sliding toothed rack I that is in gear with the toothed wheel on the looper
drum and the roller H is mounted on one arm of a bent lever K the other arm of
which is arranged to actuate by means of a connecting rod L the rod M to which
the knobs e are connected by means of the adjustable screw-pins N and O. The
inclination and shape of the slots E F are such that the intended action viz. the
forward and backward rotation of the drum f, and reciprocation of the underthread
reel a is effected to the required extent and at the required times.
The needle of the sewing machine acts in combination with the looper hook f¹
and the underthread reel a, as follows:-
The plate A is moved to and fro for each revolution of the crank C, that is to
say, during one upward and downward movement of the needle i. On the down-
ward movement of the needle, the slot E acts to rotate the looper drum so far back
that the looper hook f' passes behind the needle. On the next following upward
movement of the needle, the looper drum f is again rotated forwards, so that the
looper hook f by passing behind the needle, draws the upper thread into a loop,
and lays the same around the part annular groove m in such a manner that the
under thread reel a can pass through the loop thus formed. The slot serves to
move the underthread reel in such a manner that the said reel first passes outside
the looper drum, and then only after the loop of the upper thread has been formed
by means of the looper hook, does the reel again pass into the looper drum.
k is the upper thread and the under thread.
Assuming that a stitch has been made, that the machine is in action and about
to make a fresh stitch that the needle has assumed its highest position, and that
the under thread reel a is in the position shown in Figs. 6, 7, 8 . inside the
looper drum, and that the plate A is moving to the right, then the action is as
follows:-
The outer bent end E¹ of the slot E will act in such a manner that the looper
drum will be rotated back to some extent, this latter operation having an object
that will be hereinafter described. Then the looper drum will remain stationary
by reason of the straight part of the slot E in which the roller G then moves
and the inclined part F' of the slot. F will come into action. The position of the
parts when the outer end of the portion F' of the slot F commences to act is shown

page_text: in Figs. 6, 7 and 8 which are respectively a longitudinal section, a front or end
elevation looking towards the needle and a plan of the looper mechanism. As the
plate A continues to move the portion of the slot Facts to move the under-
thread reel a out of the looper drum F and into the position shown in Figs. 9
and 11. Then the underthread reel will remain stationary by reason of the
straight portion F, of the slot in which the roller H then works, whilst the looper-
drum will be rotated back by the inclined portion E³ of the slot E in the direction
of the arrow I, Fig. 7 and into the position shown in Fig. 10.
The needle will then arrive at the end of its downward stroke and into the
position shown in Fig. 10. Then by the further rotation of the crank C, the
plate A will be moved in the direction of the arrow III, Fig. 1. The looper drum
will then advance in the direction of the arrow IV Fig. 13, so as to engage with
the upper thread (Fig. 13) and draw it into a loop. The underthread reel a at
this time remains stationary and in the extreme left-hand position shown in
Figs. 12 to 14 corresponding to the position in which the looper hook fengages
the upper thread k, and in Figs. 15 to 17, corresponding to the position in which
the upper thread k is opened out into a loop.
The roller H then begins to pass into the portion F¹ of the slot F whilst the
roller G will rub along the end of the inclined portion E3 of the slot E. The loop
of the upper thread k will be opened out a little more, because of the looper drum f
being rotated to a further small extent; and then the underthread reel a will be
carried through the opened out loop, whilst the needle will rise to a further extent,
see Figs. 18, 19 20.
Finally the roller G will enter the outer part E¹ of the slot E whereby the
looper hook will be rotated to a further extent and release the thread lying in
the groove m, by reason of the exit end n of
moving further towards the left Figs. 18-19.
have been passed by the action of the inclined
roller H through the loop of the upper thread
thread-tightener.
the groove m in the looper drum
The underthread will at this time
portion F1 of the groove F on the
which is tightened by the upper
The groove m in the looper drum is suitably rounded at a point below the
looper hook so that it readily gives off the loop of the upper thread k, and is led
at n to the edge of the said drum.
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 :-
A sewing machine constructed with a large under thread reel embraced by a
carrier that serves also as a thread tension device, a hollow looper drum formed
or provided with a looper hook and thread groove m and arranged to inter-
mittently rotate, and a fixed casing h, the arrangement being such that the said
under thread reel can be moved to and fro within the hollow looper drum and
casing by two connected knobs or parts such as e, so that the upper thread & when
widened out by the looper hook f¹ into a loop, can be engaged by the under
thread which passes through such loop substantially as described and shown in
the drawings.
Dated this 7th day of June 1892.
G. LANGENBERGEK,
By L. W., per F. B.