Title of Invention

A YARN DELIVERING APPARATUS FOR KNITTING MACHINES HAVING A YARN RETURN OPERATING MODE

Abstract A yarn delivering apparatus (1) comprises a yarn delivering wheel (4) having a drive (3), as well as a yarn storing device (22) having a yarn laying device (21) which is provided with its own yarn layer drive (27). A control device (11) controls both drives (3, 27), providing for a pure positive operation of the yarn delivering wheel (4) on the one hand, and a yarn return delivery during shuttling of the knitting machine, on the other hand. Further, such a configuration improves the dynamics of the yarn delivering apparatus (1).
Full Text 10
October 21, 2004
MEMM P 144 abet
15 Memminger-IRO GmbH, Jakob-Mutz-StraBe 7, 72280 Dornstetten
Yarn delivering apparatus having a Yarn Return Operating
Mode
20 The invention relates to a yarn delivering apparatus
which is adapted particularly for use in knitting machines
or other yarn consuming machines which return yarn from
time-to-time. Such machines are, for example, flat knitting
machines having a reciprocating carriage; at least at one
25 of the reversal points of the carriage a short yarn return
delivery may take place. Yarn return delivery may also
occur in flat knitting machines which have several knitting
cams and yarns and where individual cams may be switched to
idling for one or several strokes.
30
Further, frequent yarn return deliveries may occur in
circular knitting machines, particularly when using the


"fully-fashioned" technique. In such a technique not only
are yarns inserted and dropped, but for certain knitted
sections it may be required to rotate the knitting cylinder
once or several times in the reverse direction to a greater
5 or lesser extent. Such an operation, in which the knitting
cylinder is rotated repeatedly forward and backward, is
referred to as "shuttling". A yarn return delivery of 0.5
meter or more may occur. The yarn delivering apparatuses
must take into account such yarn return deliveries.
10
German Patent Document DE 40 32 402 C2 describes a
storage feeder for use in flat knitting machines, and
combined with a separate dynamic yarn storing device. The
yarn discharged by the storage feeder is guided to the flat
15 knitting machine by a yarn storing device. The latter is
formed by a long lever to which a torque is applied and
which has a yarn eyelet at its free end. The lever is
pivotally supported. Further, in the yarn path a yarn brake
and a yarn tension sensor are arranged. The yarn quantity
20 delivered back upon carriage reversal is taken up by first
applying the controlled yarn brake, so that no further yarn
can be withdrawn from the yarn storage feeder. Thereafter a
torque is applied to the pivotal lever, as a result of
which the lever takes up the yarn, delivered back by the
25 flat knitting machine, by pulling lengthwise a yarn loop
which has an acute angle.
Upon the subsequent carriage reversal, first the yarn
reserve is consumed, and then the yarn brake is released
3 0 for withdrawing yarn from the yarn storage feeder.


Such a mode of yarn storage is adapted particularly
for yarn storage feeders where the knitting machine takes
the yarn from the yarn storage feeder. This, however, is
counter to the principle sought for the positive feeders to
5 allocate a predetermined yarn quantity to the knitting
machine.
An intermediate yarn storage is also feasible with the
yarn delivering apparatus according to German Patent
10 Document DE 37 32 102 C1 which disc1oses an electronically
controlled positive feeder having a yarn delivering wheel
around which the yarn is looped. The yarn running to the
knitting machine is guided over a yarn storing device which
inc1udes a lever supported for a pivotal motion through
15 almost 360°. The yarn passes through the eyelet of the
lever. Within the circ1e described by the yarn eyelet,
several yarn supporting elements are arranged which define
a polygonal yarn storing device. In case between the yarn
delivering wheel and the adjoining machine yarn remains
20 which is not taken up by the machine, such a yarn quantity
is deposited by the lever on the yarn supporting elements.
Such a mode of yarn delivery is adapted in particular
for yarn delivery at a constant yarn tension.
25
Further, German Patent Document DE 34 2 9 193 C1
describes a device for unwinding yarns from a yarn spool
and winding yarns thereon, wherein the yarn is guided by a
30 winder finger on the yarn spool. The winder finger is
mounted on a shaft which is concentric to the yarn spool
and which is driven by an electric motor. The winder finger


circulates about the outer periphery of the yarn spool. The
electric motor may be controlled according to requirements
in such a manner that the yarn is unwound from the yarn
spool or wound back thereon. For the control, a yarn
5 tensioning roller is provided by means of which the yarn
tension is monitored. When yarn return delivery is
required, the winder finger rewinds the yarn until the yarn
tensioning roller is reset into its normal position by the
tensioned yarn.
10
Yarn spools are, as a rule, combined on spool creels
from which the yarns, as needed, are withdrawn only in a
passive manner even for long sections. To involve the yarn
spools in the active winding and unwinding steps is
15 undesirable in many cases and is not even possible for
larger distances between the yarn spools and the knitting
machine.
It is accordingly an object of the invention to
20 provide a yarn delivering apparatus which may process
occasionally occurring yarn return deliveries in up-to-date
knitting machines and other textile machines.
The above object is achieved with a yarn delivering
25 apparatus as defined in c1aim 1 or c1aim 20.
The yarn delivering apparatus according to c1aim 1
inc1udes a yarn delivering wheel which, by means of a
drive, may be rotated in two opposite directions for
30 delivering the yarn. The yarn run is essentially
tangential. A first direction of rotation serves as forward
rotation in the normal operation for yarn delivery in a


yarn delivering direction to a yarn consuming station. The
reverse rotation serves in the yarn return operation for
retrieving the yarn which returns from the yarn consuming
station in the yarn return direction. Such yarn portion is
5 then wound back onto the yarn delivering wheel. The yarn
becoming free at the intake side of the yarn delivering
wheel is intermediately buffered in a yarn storing device
which, as viewed in the normal yarn delivering direction,
is positioned upstream of the yarn delivering wheel between
10 a yarn brake (if such is provided) and the yarn delivering
wheel. The arrangement of the yarn storing device upstream
of the yarn delivering wheel and in the immediate vicinity
thereof preserves, on the one hand, the direct delivering
conditions between the yarn delivering wheel and the
15 knitting machine, so that the yarn delivering wheel may
allocate the desired yarn quantity to the knitting machine
or withdraw such quantity therefrom. On the other hand, the
yarn is stored without having an appreciable influence on
the tension in the wound yarn and in the portion between
20 the yarn delivering wheel and the yarn consuming station.
The yarn storing device has preferably a yarn storing
surface which is concentric to the yarn delivering wheel
and which may be either a coherent, uninterrupted surface
25 or an interrupted surface composed, for example, of several
individual surfaces. Such individual surfaces may be, for
example, supporting regions of pins or the like. The
arrangement concentric to the yarn delivering wheel makes
possible a uniform winding and unwinding, at a uniform
30 tension, of the yarn delivered back from the yarn
delivering wheel at its intake side. Preferably, with the
yarn storing device a yarn laying device is associated


which deposits the yarn, emanating from the yarn delivering
wheel, on the yarn storing surface and withdraws the yarn
therefrom. The yarn laying device may be a yarn guiding
eyelet which is guided, for example, by a suitable lever
5 along a path concentric to the yarn delivering wheel. Such
an arrangement ensures a uniform winding and unwinding of
the yarn without any appreciable tension fluctuations.
Particularly in case of elastic yarns, the latter are
prevented from being intermediately stored in different
10 extended states. Further, the yarn, when it is again guided
onto the yarn delivering wheel from the yarn storing
device, is prevented from running onto the yarn delivering
wheel with different, that is, with fluctuating tensions in
the yarn winding. Thus, in an overall sense, the above-
15 described concentric arrangement enhances the quality of
the knitted fabric.
With the yarn laying device preferably a yarn layer
drive is associated which is independent from the drive of
20 the yarn delivering wheel. Both drives may be, for example,
electric motors controlled by a control device which moves
the yarn laying device and the yarn delivering wheel
coordinated with one another. The control device
distinguishes preferably among several operating
25 conditions, for example, as defined in c1aim 10, according
to which the control deice causes the yarn laying device
and the yarn delivering wheel to move in the reverse
direction at coordinated rpm's, so that the returned yarn
is deposited on the yarn storing device without pulling new
30 yarn into the yarn storing device. When resuming normal
operation, first the thus-formed yarn reserve is used up as
the yarn delivering wheel and the yarn laying device rotate


in the forward direction with coordinated rpm's. When the
yarn reserve is consumed, the yarn laying device stops, for
example, in a fixed position, and the yarn delivering wheel
continues its forward rotation at unreduced speed. From the
5 moment the yarn laying device stops, the yarn delivering
wheel takes the yarn from the yarn spool.
The advantage of the above-described device resides in
that an associated knitting machine may shuttle as
10 frequently as desired without consuming any yarn. During
each shuttle step the yarn is wound on the yarn storing
device and then unwound therefrom. The speed of the yarn
laying device and that of the yarn delivering wheel are
coordinated with one another such that during the shuttle
15 operation no yarn is supplied from the yarn spool and thus
the total yarn quantity present in the yarn delivering
apparatus does not increase. In the shuttle operation of
the knitting machine, the yarn quantity of the yarn
delivering apparatus oscillates between a maximum value and
2 0 a minimum value which may differ from one another by more
than 1 meter.
The drive for the yarn delivering wheel and that for
the yarn laying device are constituted by respective
25 electric motors, particularly by position-regulated
electric motors. As an alternative, it is, however,
feasible to provide a drive and a c1utch arrangement
between the yarn delivering wheel and the yarn laying
device for connecting the yarn laying device with the yarn
30 delivering wheel with fixed rpm's in each instance during
charging and discharging the yarn storing device. In such a
case the drive for the yarn laying device is composed of a

7

drive/c1utch/brake combination. Because of a better
possibility of control, however, it is preferred to provide
the yarn laying device with its own electric motor drive.
5 During normal operation the yarn delivering wheel is
driven preferably with a predetermined speed which may be
derived from the operating speed or rpm of the knitting
machine. The yarn delivering wheel and the knitting machine
are sought to be driven in synchronism in a given rpm
10 ratio. Such an operation is referred to as a positive
operation. In such an operation the yarn delivering wheel
allocates the desired yarn quantity to the knitting machine
and thus determines the loop size of the knitted fabric. To
compensate for dynamic occurrences during starting and
15 stopping of the yarn delivering wheel, between the yarn
delivering wheel and the knitting machine a yarn storing
device with a small storage capacity may be provided. Such
a yarn storing device, however, does not serve for the
intermediate storage of the returned yarn; for such a
20 purpose its capacity is definitely insufficient. It is
provided merely for buffering tension peaks which may
otherwise appear during switch-on steps (starting and
stopping of the yarn delivering wheel). As the simplest
solution,.such a yarn storing device is formed by a thin,
25 light and resilient lever which holds a yarn loop.
The yarn return delivery may likewise be performed
with a predetermined rpm of the yarn delivering wheel. It
is, however, preferable to effect the yarn return delivery
30 with tension control, that is, by controlling the yarn
tension. In such an operation, during the shuttling of the
knitting machine, the yarn delivering apparatus is


continuously switched between positive drive and tension-
controlled drive (positive drive for the normal operation
and tension control for the yarn return operation).
5 The yarn laying device as well as the yarn delivering
wheel are preferably coupled to angular position sensors.
The control device is preferably provided with a counter or
another monitoring device which counts the angular steps
traveled by the yarn laying device, and preferably also
10 counts the angular steps traveled by the yarn delivering
wheel, particularly during the yarn return operation. In
the alternative, the angle traveled by the yarn laying
device as well as the yarn delivering wheel may be
registered in a different manner. The control device thus
15 monitors the quantity of the yarn intermediately buffered
in the yarn storing device. The control device may switch
over to normal operation with the yarn laying device at
rest, when the entire forward-registered path has been
traveled in reverse, or, in the alternative, when the yarn
20 laying device has reached a fixed position. As the yarn
laying device approaches its fixed position, its normal
speed may be gradually braked to zero to prevent abrupt
tension changes at the intake side of the yarn delivering
wheel. In this manner the yarn running onto the yarn
25 delivering wheel is relieved of stress. In cooperation with
the pattern storing device of the knitting machine care can
be taken that such a gradual braking takes place only when
the shuttling operation is terminated, in order to avoid a
gradual filling of the yarn storing device which would
30 otherwise occur.

Control of the yarn delivering apparatus occurs
preferably by the machine control, particularly its pattern
storing device. The latter supplies data relating to the
yarn quantities to be delivered which correspond to the rpm
5 of the yarn delivering wheel, as well as relating to the
moments of delivery start and delivery termination. The
yarn delivering apparatus converts these values in a
possibly error-free manner. It is also feasible to operate
the yarn delivering apparatus in a self-learning manner.
10 For this purpose, for example, the yarn tension is, in a
test run, held at a nominal value by tension control. In
such a proceeding the rpm's of all the yarn delivering
wheels of all the active yarn delivering apparatuses are
monitored and a suitable mean value is determined as the
15 nominal value for the subsequent positive operation.
During the positive operation, it is furthermore
feasible to monitor the self-setting yarn tensions by a
yarn tension sensor and if such tension deviates from a
20 nominal value, to effect a follow-up setting of elements of
the knitting machine. Such follow-up settings may also be
limited to instances where the deviation exceeds a
threshold value. Elements of the knitting machine to
undergo follow-up setting may be the knitting cams or the
25 product pull-off device. It is also possible to dispense
with the follow-up setting of the knitting machine or its
elements, and in case the yarn tension exceeds or falls
below the threshold values of the yarn tension, to generate
an alarm signal or a switch-off signal.
30
The yarn laying device may further be utilized for
significantly improving the dynamics of the yarn delivering

10

wheel. In this connection it has been found that in case of
a sudden yarn requirement from zero speed to a high
delivery speed, not only the drive and the yarn delivering
wheel, but the entire yarn length from the yarn spool to
5 the yarn consuming station have to be accelerated. In this
procedure the yarn has to be accelerated and furthermore,
the friction of adhesion has to be overcome. The yarn
running onto the yarn delivering wheel on its intake side
brakes the yarn delivering wheel. The acceleration of the
10 yarn delivering wheel can be significantly improved by
providing that the yarn laying device, shortly before such
an acceleration phase, produces a small yarn reserve on the
yarn storing device. Further, the yarn laying device, upon
starting of the yarn delivering wheel, is also accelerated
15 for supplying the yarn delivering wheel first with yarn
from the yarn storing device and for delivering yarn to the
yarn delivering wheel from the yarn spool only when the
yarn laying device approaches its fixed position. The yarn
storing device serves in this connection to positively
20 disconnect the yarn delivering wheel, during its
acceleration phase, from the yarn spool.
It is also feasible to effect an early start or stop
of the yarn delivering wheel in anticipation of an abrupt
25 increase or decrease in the yarn requirement (pattern in
advance). In this manner the inertia of the yarn delivering
wheel and connected components may be compensated for up to
a certain degree, and yarn tension peaks or yarn tension
drops may be reduced at the beginning or the end of yarn
30 delivery.
11

Further details of advantageous embodiments or further
developments are disc1osed in the drawing, the description
or the c1aims. In the drawing, which illustrates
embodiments of the invention,
5
Figure 1 is a front elevational view of a yarn delivering
apparatus according to the invention,
Figure 2 is a longitudinal sectional and partially
10 schematic view of the yarn delivering apparatus
according to Figure 1,

15

Figure 3 is a schematic perspective view of the yarn
delivering apparatus according to Figures 1 and
2,

Figure 4 is a schematic illustration of the yarn
delivering apparatus of Figures 1 to 3 in normal
operation,

20

Figures
5 to 9

show the yarn delivering apparatus of Figure 4 in
different positions in the yarn return delivery
operation,

25
Figure 10 shows a modified embodiment of the yarn
delivering apparatus, and
Figure 11 shows the yarn delivering apparatus of Figure 4
30 in a phase of start preparation before normal
operation.
12

Figure 1 shows a yarn delivering apparatus which
serves, for example, for delivering hard (poorly elastic)
or elastic yarns to flat knitting machines or circular
5 knitting machines. The yarn delivering apparatus 1 is
particularly adapted for delivering yarn to knitting
machines which have a strongly fluctuating yarn requirement
over time and/or which occasionally perform yarn return
delivery. The yarn delivering apparatus 1 has, as also
10 shown, for example, in Figure 2, a carrier 2 on which a
drive 3 is mounted for a yarn delivering wheel 4 shown as a
hexagonal structure. In practice the yarn delivering wheel
4 may have several wings which form, for example, a
hexagon. The drive 3 is, for example, an electric motor 5,
15 whose armature 6 is connected with a drive shaft 7 carrying
the yarn delivering wheel 4. For example, at its other end,
the armature 6 may be coupled with an angular position
sensor 8 which serves for detecting the actual angular
position of the armature 6. The electronic circuit 9 of the
20 angular position sensor 8 is connected to a control device
11 which serves for controlling the stator windings 12 of
the electric motor 5.
The yarn delivering wheel 4 has a particularly low-
25 inertia construction for permitting large rotational
accelerations thereof. For this purpose, the yarn
delivering wheel 4 has a number of identically structured,
radially differently oriented wire yokes 13, 14, 15 (and
additional, un-numbered yokes) which are supported by a hub
30 16 mounted on the drive shaft 7. The wire yokes are
generally U-shaped having a central portion 17 for the yarn
winding and further having, particularly at their sides

13

oriented toward the drive 3, a radially outward directed
projection 18 for the yarn winding. The projection 18
constitutes the intake side 19 of the yarn delivering wheel

At the intake side 19 of the yarn delivering wheel 4 a
yarn laying device 21 is provided which forms part of a
yarn storing device 22. The yarn storing device 22 further
comprises a preferably frustoconical yarn storing surface
10 23 which tapers away from the yarn delivering wheel 4 and
which is concentric to the drive shaft 7. The yarn storing
surface 23 is preferably significantly shorter in the axial
direction of the drive shaft 7 than the portions 17 of the
wire yokes 13, 14, 15.
15
The yarn laying device 21 bridges the axial distance
between the yarn storing surface 23 and the intake side 19
of the yarn delivering wheel 4. For this purpose, the yarn
laying device 21 has a tubule 24 which is made, for
20 example, of ceramic and which constitutes a yarn eyelet.
The tubule 24 is carried by a circulating lever 25 which is
supported on the carrier 2 by at least one bearing 2 6 for
rotation about an axis concentric to the drive shaft 7.
25 With the circulating lever 25 a yarn layer drive 27 is
associated, comprising a position-regulated electric motor
28. The drive shaft 29 of the latter is connected with the
circulating lever 25 by a gearing composed of two gears 31,
32. The electric motor 28 is controlled by the control
30 device 11. For this purpose the control device 11 is
connected by means of signal-carrying conductors 33 and
control conductors 34 with the electric motor 28 for

14

controlling the windings thereof. Corresponding signal-
carrying conductors 35 and control conductors 36 are also
provided for the electric motor 5.
5 With the yarn layer drive a locking device 37 may be
associated for locking the circulating lever 25 in a fixed
position. The locking device 37 may be actuated by an
electromagnet 38 controlled by the control device 11. In
case the yarn laying device 21 executes more than one
10 revolution, the locking device 37 assumes its releasing
state. For this purpose, for example, an abutment pin 38a
is provided which is movable by the electromagnet 38
between a locking position and an abutting position.
15 Further, the carrier 2 supports a yarn tension sensor
39 for detecting the tension of the yarn running
therethrough. The yarn runs at an obtuse angle over a yarn
supporting pin 42 forming a part of the yarn tension sensor
39. The yarn supporting pin 42 is coupled with a force-
20 measuring device 43 which delivers a yarn tension measuring
value to the control device 11 or any other suitable
device. The yarn tension sensor 39 may be, as illustrated
in Figure 1, accommodated in a partial housing 44, on the
frontal face of which a display 45 and several operating
25 elements 46, 47 may be arranged. As may be observed
particularly in Figure 2, the yarn path defined by the
partial housing 44 and the yarn supporting pin 42 is
oriented at an obtuse angle to the rotary axis of the yarn
delivering wheel 4.
30
As shown in Figure 3, the yarn laying device 21 serves
in particular to wind the yarn 41 onto the yarn storing

15

surface 23 and to unwind the yarn 41 therefrom. In such an
operation the yarn 41 is guided by a yarn intake eyelet 4 8
before it reaches the yarn storing surface 23. The yarn 41
may first run through a yarn brake 49 shown schematically
5 only in Figure 4. The yarn brake 49 is preferably an
uncontrolled yarn brake which sets a constant yarn-pulling
force. If required, however, a controlled braking force may
be applied to the brake elements of the yarn brake 49. For
this purpose, the brake elements are provided, for example,
10 with an electric setting device (for example, an electric
motor, an electromagnet, a piezo setting device or the
like) controlled by the control device 11. The latter
controls the yarn brake 49 preferably in such a manner that
the braking force is increased when the yarn laying device
15 21 charges or empties the yarn storing device 22, whereas
the braking force is reduced when the yarn storing device
is empty and the yarn delivering wheel pulls yarn from the
yarn spool to the knitting machine in the positive
operational mode.
20
Preferably, upstream of the yarn brake 49 a non-
illustrated intake stopper is positioned which operates
preferably optically. However, a simple mechanical stopper
formed as a sensor lever may also be used. A yarn
25 monitoring ahead of the yarn delivering wheel 4 is
preferred to a monitoring after the yarn delivering wheel
4. The yarn tension sensor 39 is not well adapted for yarn
monitoring, since even in normal operation, occasionally
zero yarn tension magnitudes may appear. Further, it should
30 be prevented in any event, that a ruptured yarn is fed into
the machine.
16

It is further feasible to utilize the yarn laying
device 21 as a stopper, that is, for monitoring the yarn.
For this purpose, the force exerted by the yarn to the yarn
laying device is monitored. If, as the yarn delivering
5 wheel rotates, the force drops to an insufficient value or
to zero, such an event is evaluated as a yarn rupture. In
practice this may be realized, for example, by holding the
yarn laying device 21 by the yarn a few millimeters away
from the abutment (pin 38a), but elastically tensioned
10 theretoward. If the yarn laying device abuts the pin 38a,
such an event is detected by a suitable sensor and is
evaluated as a yarn rupture.
The yarn delivering apparatus of Figures 1 to 3
15 operates in accordance with the functional description
which follows.
The yarn delivering apparatus has several operational
modes. Figure 4, which is a substantially schematized
20 representation for a succinct showing of conditions,
illustrates the normal operation. The yarn storing surface
23 is shown only in broken lines for distinguishing it from
a surface with yarn and a surface without yarn. In Figures
4 to 9 only a single wire yoke 14 of the yarn delivering
25 wheel 4 is provided with a reference numeral for better
following the rotation of the yarn delivering wheel 4.
Further, the end of the referenced wire yoke 14 is shown
blackened. Also, of the yarn laying device 21 only the
tubule 24 is illustrated.
30
In the normal operational mode the yarn laying device
21 is at rest; it is in alignment with the yarn intake

17

eyelet 48. The yarn delivering wheel 4 rotates, for
example, counterc1ockwise, in the direction of arrow 50.
The yarn 41 runs to a yarn consuming station in a yarn
delivery direction as indicated by the arrow 52
5 tangentially away from the yarn delivering wheel 4 over a
yarn tension sensor 39. As particularly well seen in Figure
3, the yarn is looped several times around the yarn
delivering wheel 4 and is thus fed in an essentially slip-
free manner. However, slip-causing means, such as yarn
10 lifting pins or the like may also be provided. Yarn
slippage may also be effected by a slip c1utch arranged
between the drive shaft 7 and the yarn delivering wheel or
by reducing the extent of yarn loop-around on the yarn
delivering wheel 4. For example, slippage may be generated
15 by merely positioning very few yarn turns about the yarn
delivering wheel 4. It is also feasible to have the yarn
contact the yarn delivering wheel 4 by less than an entire
loop (for example, a 3/4 loop-around). The control device
11 determines the rpm of the yarn delivering wheel 4 and
20 thus sets the speed of yarn delivery and the quantity of
the yarn delivered. This mode of operation is termed as the
positive operational mode (with tangential yarn take-off) .
When the yarn requirement of the associated knitting
25 machine drops to zero, the yarn delivering wheel 4 stops,
and thus no more yarn is delivered. From a stopped state a
normal operation may be resumed at any time according to
Figure 4.
30 When the knitting machine or other machine begins to
release the yarn 41, that is, it begins to feed it back,
the yarn delivering apparatus begins its return delivery

18

operation. The yarn delivering apparatus immediately
determines a reduction in the yarn tension at the yarn
supporting pin 42 and attempts to reinstate the yarn
tension by reversing the drive 3. The latter thus executes
5 a c1ockwise reverse rotation as indicated by arrow 53 shown
in Figure 5, and the yarn delivering wheel 4 takes up the
yarn 41 in the return delivery direction as indicated by
the arrow 54. The yarn 41 runs tangentially onto the yarn
delivering wheel 4. As depicted in Figure 5, the yarn
10 delivering wheel 4 has already executed a 30° reverse turn
which may be observed by comparing the positions of the
wire yoke 14 in Figures 4 and 5. For preserving the yarn
tension before the yarn delivering wheel 4, the control
device 11 has triggered the operation of the yarn laying
15 device 21, so that the tubule 24, as shown in Figure 5, has
been moved approximately 15° c1ockwise. In this manner the
yarn length shown in Figure 5 between the intake eyelet 4 8
and the wire yoke 14 exactly equals the sum of the yarn
length present according to Figure 4 between the intake
20 eyelet 48 and the wire yoke 14 plus the back-fed yarn
length. The motion of the yarn laying device 21 is
effected preferably not with tension control, but
"positively", that is, in accordance with a computed travel
path determined from the detected reverse rotation of the
25 yarn delivering wheel. No means are provided for detecting
the yarn tension at the yarn laying device 21. If required,
however, a tension-controlled actuation of the yarn laying
device 21 is also possible.
30 Upon a continued return feed of the yarn 41 the
conditions according to Figures 6 to 9 prevail. As seen in
Figure 6, the tubule 24 of the yarn laying device 21

19

deposits the yarn 41 on the yarn storing surface 23. During
yarn return delivery, the yarn laying device 21 runs
significantly slower than the yarn delivering wheel 4. As
depicted in Figure 6, the yarn laying device 21 has
5 executed an approximately one-quarter turn, while the wire
yoke 14 and thus the yarn delivering wheel 4 have turned by
more than one-half revolution.
As shown in Figure 7, a continued return delivery
10 results in a gradual circulation of the yarn laying device
21 about the yarn storing surface 23 as the yarn delivering
wheel 4 rotates, and the yarn storing surface 23 first
receives one turn of yarn (Figure 8) and further turns
(Figure 9), if required. Based on the conicity of the yarn
15 storing surface 23, the yarn turns are deposited in the
yarn storing device 22 side-by-side and are thus preferably
not superposed. The rpm ratio of the yarn laying device 21
to the yarn delivering wheel 4, that is, the respectively
traveled angles are computed by the formula


25 where a is the angle traveled by the yarn laying device,
(3 is the angle traveled by the yarn delivering wheel,
r1 is the diameter of the yarn storing device and
30
r2 is the diameter of the yarn delivering wheel.
20

This arrangement ensures that no yarn is pulled
through the yarn intake eyelet 48. In addition, the yarn
brake 4 9 may be applied for preventing such yarn pull-off.
5 xxx
When the knitting machine stops the return delivery of
yarn, the return delivery operation is terminated; this may
occur, for example, in the position of the yarn laying
10 device 21 and the yarn delivering wheel 4 shown in Figure
9. If the knitting machine starts to take yarn, the yarn
delivering apparatus changes into a modified normal
operational mode in which yarn is no longer taken back in a
tension-controlled manner, but rather, yarn is delivered to
15 the knitting machine again in a guantity-controlled manner,
that is, by means of predetermined rpm's set for the yarn
delivering wheel 4. During this operation the directions
indicated by arrows in Figures 9 to 5 are reversed. The
yarn laying device 21 and the yarn delivering wheel 4 thus
20 rotate c1ockwise in accordance with the above-defined angle
and rpm ratio, whereby the yarn laying device 21 takes yarn
off the yarn storing surface 23 and supplies it to the
intake side 19 of the yarn delivering wheel 4. Again, no
yarn is pulled through the yarn intake eyelet 48. This
25 modified operational mode continues until the yarn storing
device 22 is emptied, that is, until the tubule 24 has
assumed its position in the vicinity of the yarn intake
eyelet 48, as shown in Figure 4.
30 Upon reaching this point, the yarn laying device 21
stops, while the yarn delivering wheel 4 continues to
rotate unchanged. Thus, first a true normal operation is

21

obtained. While in the modified normal operation only the
yarn wound on the yarn storing surface 23 is again taken up
and delivered to the yarn delivering wheel and thus to the
knitting machine, yarn is now pulled off against the effect
5 of the yarn brake 49. The yarn return operation and the
modified normal operation may alternate arbitrarily often.
No yarn is pulled from the yarn spool through the yarn
brake 4 9 either during the yarn return operation or during
the modified normal operation.
10
While according to the starting point in the preceding
description the yarn layer drive 27 operates in an accurate
position-regulated manner, it has to be noted that this
does not necessarily need to be the case. It is also
15 feasible to utilize an electric motor 28 which is not
position-regulated and to monitor merely the position of
one of the two gears 31, 32. In the simplest case it may
suffice to provide on the gear 32 or also on the gear 31
one or more markers (bore holes) or magnets which are
20 detected by optical sensors or, respectively, by magnetic
sensors (Hall sensors). When the yarn delivering wheel 4
rotates in the reverse direction, the position or rotation
of the yarn delivering wheel is detected, and the motor 28
is energized for moving the yarn laying device 21. The
25 motor 28 may be supplied with a controlled current for
generating a predetermined torque which should be smaller
than the torque required for pulling yarn through the yarn
brake 49. In this manner the yarn storing device 22 takes
up yarn only from the yarn delivering wheel 4. When the
30 yarn delivering wheel 4 reverses its direction of rotation
to again empty the yarn storing device 22, it works against
the slight tension of the yarn laying device 21. Such a

22

tension may also be reduced by reducing the current
supplied to the motor 28. When the yarn laying device 21
reaches its position (fixed position), for example, marked
by the Hall sensor and the magnets on the gear 31 (or also
5 on the gear 32), the yarn laying device 21 is braked to a
stop, that is, it is arrested in its fixed position,, and
the yarn delivering wheel 4 pulls off new yarn from the
yarn spool while overcoming the force of the yarn brake 49.
10 As a departure from the above description, it is to be
noted that the modified normal operation which consumes the
stored yarn reserve, as well as the normal operation which
pulls yarn off the upstream-arranged spool, may proceed in
a tension-controlled manner as controlled by the yarn
15 tension sensor 39.
A modified embodiment of the yarn delivering apparatus
1 is schematically illustrated in Figure 10. The
modification resides in the configuration of the yarn
20 storing surface 23 which, in this embodiment, is divided
into individual surfaces 55, 56. These surfaces are formed
by individual pins 57, 58 which are arranged as a crown in
the vicinity of the yarn delivering wheel 4. In other
respects the previous description applies.
25
The yarn delivering apparatus 1 makes possible a
particularly rapid start and stop of yarn deliveries. For
such a purpose a dynamic operational mode may be used which
will now be described in conjunction with Figure 11. As a
30 starting point of the dynamic operational mode, prior to
yarn delivery in the yarn storing device 22, a smaller yarn
reserve is built up, for example, as shown in Figure 11.
23

The yarn reserve may even be smaller. It could be built up
by rotating the yarn laying device 21 into the illustrated
position during standstill of the yarn delivering wheel 4,
for example, by a few degrees in a c1ockwise direction.
5 During such a step, the yarn 41 is pulled through the yarn
intake eyelet 48 and over the yarn storing surface 23. This
may always occur preventively when the yarn delivering
wheel 4 stops at the end of its normal operation. It may
occur, controlled by the pattern storing device of the
10 knitting machine, merely when a highly dynamic start, that
is, an abrupt increase in the yarn requirement is expected.
Figure 11 shows the yarn delivering apparatus in its
state of preparation for a high-dynamic start. If now a
15 starting signal is emitted by the knitting machine for the
yarn delivering apparatus 1, the yarn laying device 21 and
the yarn delivering wheel 4 are simultaneously accelerated
in a counterc1ockwise direction (arrows 50, 51a). By means
of the acceleration of the yarn laying device, the yarn
20 delivering wheel 4 is first temporarily, that is, during
its run-up phase, relieved of the load of the yarn which is
otherwise pulled by the yarn delivering wheel 4 and which
extends to the yarn spool. Thus, during the run-up phase,
the yarn delivering wheel 4 merely has to overcome its own
25 inertia and that of the yarn winding carried thereby. When
the yarn delivering wheel 4 reaches its nominal rpm, for
example, after a one-half or three-quarter revolution, the
yarn laying device 21 arrives in its fixed position
underneath the yarn intake eyelet 48 and is gradually, that
30 is, softly, arrested there, until it comes to standstill.
Such an operational mode avoids yarn tension peaks between

24

the yarn delivering wheel 4 and the knitting machine in
case of a sudden yarn requirement.
A yarn delivering apparatus 1 comprises a yarn
5 delivering wheel 4 having a drive 3, as well as a yarn
storing device 22 having a yarn laying device 21 which is
provided with its own yarn layer drive 27. A control device
11 controls both drives 3, 27, providing for a pure
positive operation of the yarn delivering wheel 4 on the
10 one hand, and a yarn return delivery during shuttling of
the knitting machine, on the other hand. Further, such a
configuration improves the dynamics of the yarn delivering
apparatus 1.
25

List of Reference Characters:
1 yarn delivering apparatus
2 carrier
5 3 drive

4 yarn delivering wheel
5 electric motor
6 armature
7 drive shaft
10 8 angular position sensor
9 circuit
11 control device
12 stator winding
13, 14, 15 wire yokes
15 16 hub
17 portion
18 projection
19 intake side
21 yarn laying device
20 22 yarn storing device
23 yarn storing surface
2 4 tubule
25 circulating lever
2 6 bearing
25 27 yarn layer drive
28 electric motor
29 drive shaft
31, 32 gears
33, 35 signal carrying conductors
30 34, 36 control conductors
37 locking device
38 electromagnet
26

38a abutment pin
39 yarn tension sensor
41 yarn
42 yarn supporting pin
5 43 force measuring device
44 partial housing
45 display
46, 47 operating elements
48 yarn intake eyelet
10 49 yarn brake
55, 56 individual surfaces
57, 58 pins
52 yarn delivery direction (arrow)
54 yarn return delivery direction (arrow)
15 51a, 50 forward rotation (arrow)
51, 53 reverse rotation (arrow)
27

Patent C1aims:
1. A yarn delivering apparatus (1), particularly for
knitting machines having a yarn return operating mode,
5 comprising
a yarn delivering wheel (4) having an intake side (19)
and a storing portion (17) for receiving a yarn
winding,
10
a drive (3) connected to the yarn delivering wheel (4)
and drivable in two opposite directions of rotation
for delivering a yarn in the yarn delivery direction
(52) to a yarn consuming station in a normal operation
15 during forward rotation (50.) , and for rewinding the
yarn (41), returned from the yarn consuming station in
the yarn return direction (54), on the yarn delivering
wheel (4) in a return delivery operation during
reverse rotation (53), and
20
a yarn storing device (22) which is arranged upstream
of the yarn delivering wheel (4) as viewed in the yarn
delivery direction (52) for intermediately storing the
yarn (41), returned by the yarn delivering wheel (4)
25 at its yarn intake side (19) during reverse rotation
(53) .
2. The yarn delivering apparatus as defined in c1aim 1,
characterized in that the yarn storing device (22) is
30 disposed between a yarn brake (49) and the yarn
delivering wheel (4).
28

3. The yarn delivering apparatus as defined in c1aim 2,
characterized in that the yarn brake (49) is a
controlled yarn brake, whose braking force may be
switched by an electric control signal between at
5 least two magnitudes.
4. The yarn delivering apparatus as defined in c1aim 1,
characterized in that the yarn storing device (22) has
a yarn storing surface (23) concentric to the yarn
10 delivering wheel (4).
5. The yarn delivering apparatus as defined in c1aim 4,
characterized in that the yarn storing surface (23)
has a coherent structure.
15
6. The yarn delivering apparatus as defined in c1aim 4,
characterized in that the yarn storing surface (23) is
divided into individual surfaces (55, 56).
2 0 7. The yarn delivering apparatus as defined in c1aim 1,
characterized in that a yarn laying device (21) is
associated with the yarn storing device (22).
8. The yarn delivering apparatus as defined in c1aim 7,
25 characterized in that the yarn laying device (21) has
a yarn guiding eyelet (24) which is guided in a
circular path concentric to the yarn delivering wheel
(4) .
30 9. The yarn delivering apparatus as defined in c1aim 7,
characterized in that a yarn layer drive (27) is
associated with the yarn laying device (21).
29

10. The yarn delivering apparatus as defined in c1aims 1,
7 and 9, characterized in that the drive (3) and the
yarn layer drive (27) are controlled by a control
5 device (11) which operates according the following
control scheme:
a) during normal operation without previous yarn
return operation the control device (11) causes
10 the yarn laying device (21) to dwell in a fixed
position and causes the drive (3) to rotate in
the forward direction (50),
b) during yarn return operation the control device
15 (11) causes the drive (3) to rotate in the
reverse direction (53) and causes the yarn laying
device (21) to rotate in the same reverse
rotational direction at a reduced speed, and
20 c) during normal operation with previous yarn return
operation, the control device (11) causes the
drive (3) to rotate in the forward direction (50)
and causes the yarn layer drive (27) to rotate
also in the forward direction, but at a reduced
25 rpm, until it travels the path covered under a)
and/or until it reaches its fixed position.
11. The yarn delivering apparatus as defined in c1aim 10,
characterized in that the yarn laying device (21) and
30 the yarn delivering wheel (4) run at rpm's which are
at a fixed ratio to one another during rotation both
in the forward and in the reverse direction.
30

12. The yarn delivering apparatus as defined in c1aim 11,
characterized in that the rpm ratio is set in such a
manner that the yarn length delivered by the yarn
5 delivering wheel at its yarn intake side (19) to the
yarn storing device (22) during yarn return operation
equals the yarn length deposited in the yarn storing
device (22).
10 13. The yarn delivering apparatus as defined in c1aim 1,
characterized in that the drive (3) is an electric
motor (5).
14. The yarn delivering apparatus as defined in c1aim 13,
15 characterized in that the drive (3) is a position-
regulated electric motor (5).
15. The yarn delivering apparatus as defined in c1aim 9,
characterized in that the yarn layer drive (27) is an
20 electric motor (28).
16. The yarn delivering apparatus as defined in c1aim 15,
characterized in that the electric motor (28) is a
position-regulated electric motor.
25
17. The yarn delivering apparatus as defined in c1aim 1,
characterized in that a yarn tension sensor (39) is
disposed between the yarn delivering wheel (4) and the
yarn consuming station.
30
18. The yarn delivering apparatus as defined in c1aim 1,
characterized in that the drive (3) is driven at a
31

predetermined rpm in the positive delivering
operational mode at least during normal operation.
19. The yarn delivering apparatus as defined in c1aim 18,
5 characterized in that the predetermined rpm is set to
be proportional to an rpm of the knitting machine.
20. A yarn delivering apparatus (1), particularly for
knitting machines having a yarn return operating mode,
10 comprising
a yarn delivering wheel (4) having an intake side (19)
and a storing portion (17) for receiving a yarn
winding,
15
a drive (3) connected to the yarn delivering wheel (4)
and drivable in two opposite directions of rotation
for delivering a yarn in the yarn delivery direction
(52) to a yarn consuming station in a normal operation
20 during forward rotation (50), and for rewinding the
yarn (41) , returned from the yarn consuming station in
the yarn return direction (54), on the yarn delivering
wheel (4) in a return-delivery operation during
reverse rotation (53) ,
25
a yarn tension sensor (39) disposed between the yarn
delivering wheel (4) and the yarn consuming station,
and
30 a control device (11) which drives the drive in normal
operation in the positive operation and in yarn return
operation in the yarn tension regulating operation.
32

21. The yarn delivering apparatus as defined in c1aim 20,
characterized in that during the positive operation
the rpm of the drive (3) equals to a predetermined rpm
5 at least within predetermined limits of the yarn
tension.
22. The yarn delivering apparatus as defined in c1aim 20,
characterized in that during the yarn return operation
10 the rpm of the drive (3) is set by the control device
(11) based on the yarn tension in such a manner that
the yarn tension remains possibly constant during the
yarn return operation.
15 23. The yarn delivering apparatus as defined in c1aim 1 or
20, characterized in that a dynamic yarn storing
device is provided between the yarn delivering wheel
(4) and the yarn consuming station.
20 24. The yarn delivering apparatus as defined in c1aim 1 or
20, characterized in that the yarn storing device
(22), its drive (28), the yarn delivering wheel (4)
and its drive (5) are carried by a common carrier.
25 25. The yarn delivering apparatus as defined in c1aim 24,
characterized in that the drive (28) of the yarn
storing device (22) and the drive (5) of the yarn
delivering wheel (4) are accommodated in a common
housing.
30
33

26. The yarn delivering apparatus as defined in c1aim 1,
characterized in that a control device (11) for the
drives (5, 28) is disposed in the housing.
5 27. The yarn delivering apparatus as defined in c1aim 1 or
20, characterized in that the yarn storing device (22)
comprises a circulating lever (25) which carries a
yarn guiding means (24) at its free outer end and the
pivotal or rotary axis of which is coaxial with the
10 rotary axis of the yarn delivering wheel (4).
28. The yarn delivering apparatus as defined in c1aim 1 or
20, characterized in that a slippage-causing device is
provided between the drive (3) and the yarn (41).
15
29. A method of driving a yarn delivering apparatus (1)
which comprises
a yarn delivering wheel (4) having an intake side (19)
20 and a storing portion (17) for receiving a yarn
winding,
a drive (3) connected to the yarn delivering wheel (4)
and drivable in two opposite directions of rotation
25 for delivering a yarn in the yarn delivery direction
(52) to a yarn consuming station in a normal operation
during forward rotation (50), and for rewinding the
yarn (41), returned from the yarn consuming station in
the yarn return direction (54), on the yarn delivering
30 wheel (4) in a return-delivery operation during
reverse rotation (53),
34

a yarn tension sensor (39) disposed between the yarn
delivering wheel (4) and the yarn consuming station,
wherein the drive (3) is driven in a positive
operation in the normal operation, and in a tension-
regulating operation in the yarn return operation.
?

£P MAJUMDARl
IT I- 8. DAVAR ft CC*.
APPLICANTS' A«EI«r
35

A yarn delivering apparatus (1) comprises a yarn
delivering wheel (4) having a drive (3), as well as a yarn
storing device (22) having a yarn laying device (21) which
is provided with its own yarn layer drive (27). A control
device (11) controls both drives (3, 27), providing for a
pure positive operation of the yarn delivering wheel (4) on
the one hand, and a yarn return delivery during shuttling
of the knitting machine, on the other hand. Further, such a
configuration improves the dynamics of the yarn delivering
apparatus (1).

Documents:

01221-kolnp-2007-abstract.pdf

01221-kolnp-2007-claims.pdf

01221-kolnp-2007-correspondence others 1.1.pdf

01221-kolnp-2007-correspondence others 1.2.pdf

01221-kolnp-2007-correspondence others 1.3.pdf

01221-kolnp-2007-correspondence others.pdf

01221-kolnp-2007-description complete.pdf

01221-kolnp-2007-drawings.pdf

01221-kolnp-2007-form 1.pdf

01221-kolnp-2007-form 18.pdf

01221-kolnp-2007-form 2.pdf

01221-kolnp-2007-form 26.pdf

01221-kolnp-2007-form 3.pdf

01221-kolnp-2007-form 5.pdf

01221-kolnp-2007-international publication.pdf

01221-kolnp-2007-priority document.pdf

1221-KOLNP-2007-ABSTRACT.pdf

1221-KOLNP-2007-AMANDED CLAIMS.pdf

1221-KOLNP-2007-AMANDED PAGES OF SPECIFICATION.pdf

1221-KOLNP-2007-CORRESPONDENCE-1.4.pdf

1221-KOLNP-2007-CORRESPONDENCE.1.3.pdf

1221-KOLNP-2007-CORRESPONDENCE.pdf

1221-KOLNP-2007-DESCRIPTION (COMPLETE).pdf

1221-KOLNP-2007-DRAWINGS.pdf

1221-KOLNP-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

1221-KOLNP-2007-EXAMINATION REPORT.1.3.pdf

1221-KOLNP-2007-FORM 1.pdf

1221-KOLNP-2007-FORM 18.1.3.pdf

1221-KOLNP-2007-FORM 2.pdf

1221-KOLNP-2007-FORM 26.1.3.pdf

1221-KOLNP-2007-FORM 3 1.1.pdf

1221-KOLNP-2007-FORM 3-1.2.pdf

1221-KOLNP-2007-FORM 3.1.3.pdf

1221-KOLNP-2007-FORM 3.pdf

1221-KOLNP-2007-FORM 5.1.3.pdf

1221-KOLNP-2007-GRANTED-ABSTRACT.pdf

1221-KOLNP-2007-GRANTED-CLAIMS.pdf

1221-KOLNP-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1221-KOLNP-2007-GRANTED-DRAWINGS.pdf

1221-KOLNP-2007-GRANTED-FORM 1.pdf

1221-KOLNP-2007-GRANTED-FORM 2.pdf

1221-KOLNP-2007-GRANTED-LETTER PATENT.pdf

1221-KOLNP-2007-GRANTED-SPECIFICATION.pdf

1221-KOLNP-2007-OTHERS-1.1.pdf

1221-KOLNP-2007-OTHERS.1.3.pdf

1221-KOLNP-2007-OTHERS.pdf

1221-KOLNP-2007-PETITION UNDER RULE 137.pdf

1221-KOLNP-2007-REPLY TO EXAMINATION REPORT.1.3.pdf

abstract-01221-kolnp-2007.jpg


Patent Number 248339
Indian Patent Application Number 1221/KOLNP/2007
PG Journal Number 27/2011
Publication Date 08-Jul-2011
Grant Date 05-Jul-2011
Date of Filing 09-Apr-2007
Name of Patentee MEMMINGER-IRO GMBH
Applicant Address JAKOB-MUTZ-STR.7, 72280 DORNSTETTEN
Inventors:
# Inventor's Name Inventor's Address
1 HUSS, ROLF KIRCHHOFWEG 5 72290 LOSSBURG
PCT International Classification Number D04B15/48;B65H51/22,
PCT International Application Number PCT/EP2005/010754
PCT International Filing date 2005-10-06
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10 2004 051 520.4 2004-10-21 Germany