Spinning machine with sliver-feed interrupter

A spinning machine for the production of yarn in which at each spinning station, a yarn break sensor is provided in conjunction with a sliver-stopping unit. The latter is electrically actuated and to reduce peak current draw upon simultaneous thread breaks, a time-delay circuit, e.g. using shift registers, is provided to time-stagger the operation of the stopping units.

FIELD OF THE INVENTION 
Our present invention relates to a spinning machine, and more particularly, 
to a spinning machine having a multiplicity of spinning stations each of 
which is provided with a yarn-breakage sensor and with a 
sliver-feed-stopping element intended to respond to that sensor for 
interrupting sliver feed in the event of the detection of a yarn break. 
BACKGROUND OF THE INVENTION 
Spinning machines of this type can include, inter alia, ring-spinning 
machines, open-end (OE) spinning machines and bell-cup spinning machines. 
Such spinning machines can have a large number of spinning locations or 
stations and, as a rule, several hundred spinning stations and even in 
cases of a thousand spinning stations. Each such spinning station can be 
provided with a spindle or other means for taking up a spinning bobbin or 
spool and for driving the spinning means at this station to impart a twist 
of the sliver which is fed through a drafting frame and between the 
drafting rollers thereof to the spinning location so that the sliver is 
twisted to form the yarn. 
The sliver-feed-stopping unit which may be provided for each such station, 
generally in the form of a clamp engageable with the sliver upstream or at 
least some of the drafting rollers of the drafting frame serve, in the 
case of a thread break, to prevent further intake of the sliver at the 
respective station thereby interrupting sliver feed until the defect is 
corrected. This eliminates unnecessary consumption of the sliver and 
prevents sliver which is fed undesirably and under conditions in which it 
cannot be spun into yarn, from detrimentally affecting the moving parts of 
the spinning station and creating a situation requiring clearing of the 
sliver fibers. 
When there is a yarn break, moreover, continued feed of the sliver through 
a drafting frame may cause the sliver which continues to be fed 
uncontrollably to wind up on an upper or lower drafting roller so that the 
drafting frame can be detrimentally affected. 
In OE spinning machines, in addition, the uncontrolled feed of the sliver 
following a unit break can plug the spinning unit at the spinning station. 
As a consequence, a variety of yarn feed interrupters have been provided 
heretofore and in general such devices have been electrically operated, 
i.e. tripped by an electric current pulse. The current pulse energizes a 
solenoid or magnet coil which can release or actuate a mechanical device 
for preventing further in-feed of the sliver at each location suffering a 
yarn break. 
A simple sliver-feed interrupter can be a normally open clamping device 
which has an element provided for each station so that the element is 
released upon detection of a yarn break at each station to clamp off 
further advance of the sliver. 
Each clamping element is associated with an electromagnet which can 
displace a member retaining the clamping element in its open position when 
the coil of that device receives a current pulse, the element moving into 
its closed position. 
When the yarn break is cured by the operator or by the automatic yard-tying 
carriage, the drafting frame is again closed and/or the clamping device 
reopened so that the sliver or slivers will once more be fed to the 
respective spinning stations and will be drawn and spun. 
Each electrically actuatable sliver-stopping-device requires for its 
respective actuation, the electrical energy for a brief time. This energy 
consumption is in the form of a current pulse which has a duration of, for 
example, 10 to 20 milliseconds. 
Thread breakages arises relatively seldomly and are distributed 
statistically over the spinning frame. In normal operations of a spinning 
machine, it is not a problem to have available sufficient electrical 
energy from even a comparatively low power source for operation of the 
sliver-feed-stopping units which may simultaneously be actuated because of 
such statistically distributed yarn breakages. 
However, under certain operating conditions, problems arise. 
These operating conditions include restarting of a machine from standstill, 
operation of a part of the machine, where only some of the spinning 
stations are activated, and like conditions which tend to place excessive 
stress on the yarns and either require a large number of sliver-stopping 
elements to be actuated simultaneously because of the nature of the 
operation or because an excessively large number of yarn breakages may 
occur. 
In these conditions and in others, several hundred sensors may detect 
simultaneous thread breakages and substantially simultaneously energize 
the respective electromagnets of the sliver-stopping units. 
While these occurrences are infrequent, the times at which they recur 
result in an inordinately high current demand, especially if all of the 
sliver-feed-stopping solenoids are simultaneously actuated to create a 
significant problem with respect to continued operation of the spinning 
machine. It is therefore desirable to abate the high-peak current demand 
presented by such a phenomenon. 
OBJECTS OF THE INVENTION 
It is the principal object of the present invention to provide, in a 
spinning machine of the type described, conditions under which the 
instantaneous or peak current resulting from simultaneous operation of a 
plurality of sliver-feed-stopping elements can be reduced. 
Another object of the invention is to provide an improved method of 
operating a spinning machine with this result. 
Yet another object of the invention is to provide a method of and an 
apparatus for the spinning of sliver into yarn whereby high current draw 
resulting from simultaneous operation of sliver-stopping elements is 
precluded. 
SUMMARY OF THE INVENTION 
These objects and others which will become apparent hereinafter are 
attained, in accordance with the invention, in a spinning machine of the 
type described provided with means such that the triggering of the 
sliver-feed-stopping elements is affected, in the case of a large number 
of thread breaks simultaneously, only with a time delay so that actuation 
of the respective elements is effected in a time-staggered relationship. 
Time-delay means is thus provided for the actuation of these stopping 
elements. 
The instantaneous total current amplitude resulting from simultaneous 
current supply to a multiplicity of stopping elements can thereby be 
reduced to a level not substantially higher than the level which results 
from the statistically occurring simultaneous thread breaks. 
Because the peak current which must be supplied is thereby reduced to a 
very significant extent, advantages are gained where high-current or even 
low-current sources are provided and the current supply network for the 
sliver-stopping elements of the machine can have relatively small 
dimensions. The electrical network and harness can be simplified and 
reliability and safety increased. 
It is especially advantageous to initiate a time-staggered triggering of 
the sliver-feed-stopping elements only when so many stopping elements must 
be energized simultaneously that the total current required for such 
energization exceeds a predetermined level. This means that for the normal 
statistically arising triggerings of these elements, no time staggering is 
effected and a time staggering only is provided when there is a danger 
that the simultaneous current demand will exceed a predetermined level. 
The time-delay means can be any conventional time-delay device and, for 
example, each sliver-feed-stopping element can be provided with a 
respective time-delay unit, for example, an RC (resistance capacitance) 
network, a delay clock or the like. The stop elements can be divided into 
groups, with the several groups being time-staggered in operation but all 
of the elements of a given group operated simultaneously, i.e. without 
time-staggering. A particularly preferred circuit arrangement for the 
actuation of the sliver-stopping devices includes a time-delay means with 
various time delays and having at least one shift registering and at least 
one pulse generator for generating a shift-stepping pulse. A respective 
memory cell of the shift register can be provided and for each stopping 
element or an individual memory cell can control several stopping units. 
To reduce the number of connecting conductors, several shift registers can 
be used, either in parallel operation and/or in a sequential operation. 
For sequential operation one shift register or a group of shift registers 
can trigger the next shift register or group of shift registers in 
cascade, or the sequential operation of the shift registers can be 
effected by a master shift register for controlling the subsidiary shift 
register.

SPECIFIC DESCRIPTION 
FIG. 1 shows a spinning station 10 of a spinning machine which can have 
hundreds to in excess of a thousand such stations, each of which includes 
a drafting section 11 through which the sliver with a slight twist can be 
passed for drawing in accordance with the usual practice. The drawn sliver 
passes through a yarn-guiding eye 16 and is spun by means of a spindle 14 
and, in the particular case of this spinning machine, with the aid of a 
spinning ring upon which a traveller 17 entrained by the yarn as it is 
twisted, is entrained. A bobbin of the spun yarn is wound on the spindle. 
The bobbin core or sleeve can be doffed from the spindle in the usual 
manner. 
The spinning rings of the respective station is carried on ring bench or 
platform 18 which can be raised and lowered and upon this member each 
spinning station can be provided with a respective yarn-break sensor 19. 
In the embodiment illustrated, these sensors monitor the passage of the 
traveller 7 inductively and, as long as there is a uniform circulation of 
the traveller in front of the sensor 19, the sensor considers that there 
is no problem requiring interruption of the sliver feed, i.e. there is no 
yarn breakage. 
However, should the passage of the traveller 17 be delayed, the sensor 
determines that there has been a yarn breakage. Of course other types of 
spinning machines may make use of other yarn-breakage sensors and any 
yarn-breakage sensor conventional in the art may be used. 
As long as there has been no yarn break, the sensors 19 and their signal 
generators 20 supply no yarn-break signal. When, however, the yarn 16 does 
break, the signal generator delivers for a very brief period a pulse or 
even a continuous signal to the control circuitry 21 of an electromagnet 
28' adapted to retract a pin 33 and release the sliver-stopping element. 
Each circuit 21 thus forms part of a sliver-stopping unit 22 for the 
respective station, the circuits 21 of all or groups of these units being 
provided with a time-delay circuit as represented at 29. 
Consequently, each spinning station 10 is provided with a respective 
yarn-break sensor 19, a signal generator 20 outputting a signal which 
serves to interrupt sliver feed, and the aforementioned sliver-stopping 
unit 22 with its control circuit 21. When a thousand stations 10 are 
provided in a given spinning machine, a thousand each of the components 
19, 20, 21 and 22 and time-delay means 29 can be provided for each of the 
stations or for groups of stations which can have their stopping units 
simultaneously operated without difficulty. Each unit can be provided with 
a respective time-delay circuit or a given time-delay circuit can be 
provided for a number of units, a minimum number of units operating by a 
time-delay circuit being one. 
The units 22 each comprise an element 30 movable upwardly and downwardly 
along an inclined path as represented by the double-headed arrow A and 
adapted to clamp the respective sliver against a stationary anvil 31 
disposed between the drafting frame 11 and a supply can or spool for the 
sliver 13. 
A coil spring 32 biases member 30 into its clamping position and a detent 
formed by the pin 33 normally holds the member 30 in its open position 
against the force of spring 32. When the electromagnet or coil 28' is 
energized, it retracts the pin to release the detent and permit the spring 
to press the sliver against the anvil. 
The output of the signal generator 20 is connected by a conductor 34 to the 
electronic or electromagnetic switch 26 of the circuit 21 to close the 
latter in response to a yarn-break signal when the time-delay circuit 29 
simultaneously provides an output to the circuit 21. As can be seen from 
FIG. 2, this is ensured by an AND-gate 40, one of whose inputs is 
connected to the time-delay circuit 29 whereas the other input derives 
from the signal generator 20. 
The output of the AND-gate 40 controls the electronic switch 26 which has 
an input current terminal 41 connected to a current source 25 (FIG. 1), to 
connect this source to the electromagnet 28'. The source 25 may be an AC 
source or a DC source, on the spinning machine or removed therefrom. 
As can be seen from FIG. 2, the time-delay circuit 29 is formed as a shift 
register 42 which has m storage or memory cells and correspondingly n 
outputs where n corresponds to the number of sliver-stopping units 22 or 
circuits 21 controlled by the shift register. 
When the machine has a large number of spinning stations and hence a very 
large number of sliver-stopping units, a number of commercially available 
shift registers can be connected serially in cascade to provide the 
requested number of outputs. To simplify the illustration, only the 
connection between the No. 1 output of the shift register 32 with its 
circuit 21 has been illustrated. The remaining outputs are connected to 
correspond to circuits 21 of the other sliver-stopping unit 22 of the 
spinning machine. 
When there is no severe condition requiring the time delay, all of the 
outputs of the shift register have potentials or L-signals which gate the 
respective outputs from the signal generators 20 directly through for 
operation of the respective sliver-stopping elements without time delay. 
Under these circumstances the thread breaks which statistically occur and 
may or may not overlap to a limited extent, seldom result in a critical 
current draw and indeed generally 4 to 10 thread breaks can occur 
simultaneously without any difficulty. The current drawn from the source 
25 can then be 5 to 10 times the current draw for a single sliver-stopping 
unit. 
According to the invention, however, a current-level sensor 43 is provided 
in circuit with the source 25 and can respond, for example, when more than 
3 thread breaks occur simultaneously or even on a threshold equivalent to 
a far larger number if the circuit arrangement can withstand the 
additional draw, to trigger the shift register 42 at its reset input R to 
establish that all of the outputs of the shift register, an O signal 
blocking the respective gates, until with a time delay determined by the 
stepping of the shift register, each output is brought to the level L 
again at a clock frequency T determined by the pulse generator 50 which 
acts to deliver the stepping pulses to the shift register. 
A status signal S corresponding to the L signal is continuously impressed 
on the status-input terminal 44 of the shift register. The time delay for 
a given sliver-stop unit will depend, of course, on the delay time built 
into the delay line formed by the shift register since the outputs 1 . . . 
n are supplied with the gating potentials in succession and with an 
interval between them equal to the time constant of the shift register. 
The L signal can have a value "1". 
As each "1" signal develops at the respective output of the corresponding 
shift register cell, the respective AND-gate 40 is enabled and should 
there be a signal at this AND-gate from the respective signal generator, 
the output of the AND-gate will trigger the respective electromagnet 28 or 
28' for its switch 26. 
If it is assumed that each shift register will thereby deliver enabling 
signals in succession to 10 stopping units, only one-tenth the maximum 
current draw will be experienced even if all these units require operation 
of the respective sliver-stopping elements. 
Of course each shift-register cell can operate a number of such units in 
parallel corresponding to the maximum permissible current draw. 
If the clocking frequency T is low, it is possible that only a single 
sliver-stopping unit will be operated at each instant. However with 
increasing frequency T, it is impossible that there will be overlap in 
operation or a greater number of units energized simultaneously and the 
current source 25 should be diminished accordingly. 
Alternately the shift register 42 can operate in the so-called ignition 
distributor mode. Here the status signal S is varied to modify the L 
signal in the cadence of the clock signal from output to output so that 
all remaining outputs have an O signal. In this case, the clock frequency 
can be held so low that the current drain from the source 25 is at a 
maximum until the current required for a single stop unit. At higher 
frequencies each switch 26 can be held closed for a sufficient period and 
is then reopened. 
The current-monitoring unit 43 can be eliminated when the shift register 42 
continues to operate cyclically in the ignition distributor mode in a 
uninterrupted manner. These various possibilities can be employed also 
with the embodiments described below so that repetition as to how the 
shift register can be used alone or in combination with others to achieve 
various modes of time-delayed operation of the sliver-clamping elements 
need not be described. 
Furthermore, while the use of the current detector or an equivalent for 
bringing into play the time-delay units when a potential excessive current 
drain may arise is preferred its use or omission are possible with each of 
the embodiments described and hence need not be separately discussed. 
FIG. 3 shows four shift registers 42 connected in parallel, i.e. the status 
bus 44 is connected with the status inputs of all of the shift registers 
while the clock bus 45 is connected with the clock inputs of all of the 
shift registers. In this embodiment, with each step of the parallel shift 
registers, four stop units 22 can be simultaneously enabled so that the 
switching time over the entire assembly of stop units can be reduced to 
one-quarter of each of the four shift registers need have only n/4 
outputs. 
Since the four shift registers can be located at four different positions 
along the row or rows of stop units, the number of conductors and 
corresponding conductor lengths can be reduced. Of course the number of 
parallel-connected shift registers can also deviate from four, i.e. can be 
greater or less, the number depending upon the peak current load which is 
tolerable and the number of sliver-stop units which can be operated by 
this mechanism permissible peak current without overlapping. 
The embodiment shown in FIG. 4 comprises a plurality of groups, each of 
four shift registers 42. Of course the number of such shift registers can 
deviate from four. The status bus 44 is connected to the inputs of the 
respective shift registers via electronic switches 46, the first of which 
is triggered by an input signal E while the others are triggered from the 
preceding group of shift registers. 
The clock bus 45 is connected in parallel to all of the shift registers as 
represented by the arrows 45' used to avoid excessive conductors which may 
obscure the circuit. 
The signal E can be generated by a current-monitor circuit 43 or, when a 
simple cycling system is used, the output from the last shift register of 
the last group, or the last cell of a shift register of one of the groups 
when, as shown, the shift registers of each group are connected in 
parallel. 
If overlap is to be permitted, the trigger signals for the next group can 
be branched from an earlier storage cell as shown in dot-dash lines. 
In this embodiment the total switching time across the outputs of the shift 
register can be reduced to one-quarter of the time for switching through 
the shift register in the first embodiment and to the extent overlap of 
simultaneous actuations of the sliver-stopping mechanism may be permitted, 
still further reductions may be made. 
The number of outputs per shift register in this embodiment is reduced 
still further by comparison with the embodiment of FIG. 3 as a result of 
the grouping of the shift registers. The wiring harnesses are also reduced 
in complexity by comparison with the latter embodiment. 
In the embodiment of FIG. 5, each shift register output is connected in 
parallel to four sliver-stopping units, again reducing the total number of 
outputs required by the shift register by the factor of the number of 
stopping units connected to each output. 
The switching time is likewise reduced by a factor of 1/m where m is the 
number of circuits 21 connected to each shift register output. 
In the embodiment of FIG. 6, each of the shift registers 42 is connected to 
the status line 44 by a respective electronic switch 46 operated from the 
six outputs, for example of a command shift register 47. The shift 
registers 42 are stepped as previously described with a clock frequency T1 
while the shift register 47 receives a statistic signal S and another 
clock frequency T2 which is lower than the clock frequency T1. 
In this embodiment, the shift registers 42 are enabled one after another, 
in accordance with the reduced clock frequency T2. By selecting the clock 
frequencies and the number of outputs per shift register, a certain number 
of sliver-stopping units can be operated simultaneously and hence this 
number is selected to be, for example, four, or a number which will not 
provide an excessive peak current. 
During starting of the machine when numerous thread breaks may be expected, 
the clock frequencies can be adjusted to reduce the overlapping or 
eliminate it entirely. 
After startup and several cycles of the shift registers, the clock 
frequency T2 can be increased to allow significantly more overlapping, 
thereby reducing the delay time for operation of any of the 
sliver-stopping units to an extremely small value. This latter mode of 
operation, of course, can coincide with a purely statistical occurrence of 
thread breaks. 
The system can be operated cyclically in the manner of an ignition 
distributor and here again there is a reduction in the number of outputs 
per shift register and to the extent that the number of outputs can be 
reduced, the complexity of the wiring can be reduced as well. 
It can also be provided that one or more of the switches 46, after being 
closed at the beginning of the startup of the spinning machine, remains 
closed to the next shutdown of the spinning machine so that the shift 
register 47 becomes effective only during startup, while the ignition 
distributor function is effected thereafter. 
Another embodiment utilizing this principle but wherein the shift register 
47 resets the shift registers 42 or enables them directly has been shown 
in FIG. 7. This circuit which can also operate with an ignition 
distributor function, can make use of commercially available shift 
registers with 16 outputs each.