Method for automatically compensating density or thickness variations of fiber material at textile machines, such as cards, draw frames and the like

For the automatic compensation of density or thickness variations of fiber material at textile machines there is measured the density of a fiber material mass fed to a fiber feed device and the density of the fiber material mass at the textile machine outlet. The resultant measurement signals are delivered to a control for regulating the rotational speed of a feed roll of the fiber feed device in accordance with both measured density signals. The fiber feed device comprises the feed roll and a coacting feed plate. The feed roll, although rotatable, is spatially stationary and is pivotal from a starting position in the absence of the fiber mass into an operative position into contact with an abutment when there is present a fiber mass whose density variations are to be detected. By positionally fixing the feed plate during the detection operation different forces arise, depending upon the thickness or density of the fiber mass, in the nipping zone between the feed roll and the feed plate. These different forces can be detected by different measuring elements which produce the measurement signals delivered to the control. Due to the rotational speed variation of the feed roll there are compensated irregularities in the thickness or density of the mass of fiber material in the nipping zone during transfer of the fiber mass from the feed plate to a coacting element such as a licker-in roll in the case of a card constituting the textile machine.

CROSS-REFERENCE TO RELATED APPLICATION 
This application is related to our commonly assigned, co-pending U.S. 
application Ser. No. 07/132,204 filed, Dec. 10, 1987 and entitled "METHOD 
AND APATUS FOR DETECTING THE DENSITY OR THICKNESS AND VARIATIONS 
THEREOF OF FIBER MATERIAL AT THE INFEED OF A TEXTILE MACHINE AS WELL AS 
METHOD AND APATUS FOR EVENING THE DENSITY OR THICKNESS VARIATIONS Of 
FIBER MATERIAL AT THE INFEED OF A TEXTILE MACHINE" 
BACKGROUND OF THE INVENTION 
The present invention relates to a new and improved method of, and 
apparatus for, automatically compensating or evening the thickness or 
density fluctuations or variations at textile machines, such as cards, 
drawing frames and the like. 
In the context of this disclosure the terms evening or compensating the 
"density" or "thickness" variations of the fiber or fibrous material, or 
equivalent expressions, are generally intended to mean essentially or 
substantially evening out or compensating such density or thickness 
variations or irregularities so that the fiber or fibrous material 
delivered by the textile machine possesses an essentially or substantially 
uniform weight per unit length or density. 
Generally speaking, the method for automatically compensating or evening 
thickness or density fluctuations in a fiber mass at textile machines, 
such as cards or carding machines, draw frames and the like, comprises 
deriving signals at the infeed or input side of the textile machine which 
are dependent upon the momentary density or thickness of the mass of fiber 
material, such as a batt or sliver, located in a fiber feed device and 
deriving signals at the output of the textile machine which are dependent 
upon the momentary thickness or density of the delivered mass of fiber 
material, such as a web or sliver at the output of the textile machine. 
These derived signals are processed in order to control the infeed speed 
of the mass of fiber material to the textile machine as a function of such 
derived signals. 
Not only is the invention concerned with the aforementioned method aspects, 
but also the invention pertains to a new and improved apparatus for the 
performance of the method aspects. 
In its broader aspects, the apparatus for accomplishing the method is 
manifested by the features that there is provided a fiber infeed means or 
device comprising at least one driven or driveable rotatable feed roll for 
feeding the fibrous material or fiber mass to the textile machine. A fiber 
feed element, typically but not exclusively a fiber feed plate, coacts 
with this driven rotatable feed roll and forms therebetween a nipping zone 
or region or gap for the fiber material. There is also provided a device 
or apparatus at the outlet or output side of the textile machine for 
determining the thickness or density of the delivered mass of fiber 
material, such as the delivered web or sliver. Such device may be of the 
type disclosed in the European Patent No. 78,393, published May 14, 1986 
and the cognate U.S. Pat. No. 4,539,729, granted Sept. 10, 1985, the 
disclosure of which is incorporated herein by reference. Measuring or 
sensing means detect the fiber density or thickness variations prevailing 
in the nipping zone or region or gap --hereinafter usually simply referred 
to as the nipping zone or region--. Likewise, the measuring or sensing 
means detect the thickness or density of the delivered mass of fiber 
material. Each such measuring or sensing means deliver respective output 
signals in accordance with the detected or measured density or thickness 
of the corresponding mass of fiber material. To correct the variations in 
the fiber density or thickness infed into the textile machine the 
respective measuring or sensing means can deliver the detected or derived 
measuring signals to a control device or control for the evening or 
compensation of the density or thickness variations of the infed fiber 
material. 
Evening or compensation of the density or thickness of fiber material at 
the input or input side of a textile machine, it being noted that in the 
case of a card such fiber material or mass is typically termed a fiber 
batt or lap, is an important prerequisite for the uniformity of the fiber 
product, again in the case of a card typically termed a web or sliver, 
delivered by the textile machine. This prerequisite or precondition 
assumes an even greater importance with increasing processing speeds of 
the textile machine because fewer machines are employed for the same 
quantity of fiber material, such as the batt or lap, which is to be 
processed, so that there is reduced the possibility of doubling throughout 
a larger number of machines. 
Because of the importance of this problem there has evolved a considerable 
amount of patent documentation and literature proposing solutions 
attempting to fulfill such objectives. In the following description there 
will be enumerated, by way of example, a number of such patents. 
For instance, in the U.S. Pat. No. 4,275,483, granted June 30, 1981, there 
is disclosed a fiber infeed means for a carding machine or card. The fiber 
infeed means comprises a stationarily arranged feed plate and a driven and 
movable feed roll arranged above the stationary feed plate. This driven 
and movable feed roll is pressed at both of its ends by means of springs 
against the fiber batt located between the driven and movable feed roll 
and the stationary feed plate. 
The movements or displacements of the driven and movable feed roll, caused 
by the irregularities or unevenness in the fiber batt, are detected by 
displacement sensors or transducers provided at both ends of the driven 
and movable feed roll. These displacement sensors deliver signals 
representative of the irregularities in the fiber batt to a control device 
which computes therefrom the requisite change in the rotational speed of 
the driven and movable feed roll in order to compensate the unevenness or 
irregularity of the infed fiber batt as far as possible. 
What is construed to be a notable shortcoming of this prior art system 
resides in the fact that the driven and movable feed roll, which infeeds 
the fiber material, is also used for sensing the unevenness of the fiber 
batt. This automatically leads to disturbances or deviations in the 
measuring signals, even then if measures are undertaken in the arrangement 
and construction of the drive system for the driven and movable feed roll 
in order to obtain directions of the drive forces at the driven and 
movable feed roll essentially perpendicular to the direction of movement 
of such driven and movable feed roll during the batt thickness sensing 
operation. 
The aforementioned shortcoming or problem is considered to be eliminated by 
the apparatus disclosed in the French Patent No. 2,322,943, published Apr. 
1, 1977, which proposes using a stationary but rotatable feed roll and 
sensing the unevenness or irregularities of the infed fiber material, 
namely the batt or lap delivered to the card, by means of a movable feed 
plate structure or unit which is preferably composed of a plurality of 
contiguous pedals or plates. The feed plate structure or unit, and 
specifically the pedals or plates thereof are mounted to be pivotable or 
swivelable, so that they can move towards and away from the stationary but 
rotational feed roll, to thereby sense unevenness or irregularities in the 
infed fiber material or batt. 
A shortcoming which is thought to exist in this prior art system does not 
pertain so much to the actual measuring principle involved, but to the 
manner of transfer of the fibers to a subsequent licker-in cylinder or 
roll. Due to the aforementioned pivotability of the trough-like feed 
pedals or plates in relation to the stationary licker-in cylinder or roll 
the fiber transfer position or location at the feed plates or pedals, 
moves or shifts. Consequently, the position of the fiber transfer location 
of the fiber batt from the feed plates or pedals to the licker-in cylinder 
or roll likewise alternately moves in the direction of rotation of the 
licker-in cylinder or roll and in the opposite rotational sense or 
direction. This produces disturbances in the transfer of the fibers to the 
licker-in cylinder or roll. 
A further state-of-the-art system which has been proposed, in order to 
eliminate or alleviate the initially explained drawbacks or shortcomings, 
has been described in the German Published Patent No. 2,912,576, published 
Oct. 31, 1979. In this prior art apparatus a sensor element which is 
provided near to or bordering the stationary trough-like feed plate 
detects the density of the fiber batt which is in contact with the 
trough-like feed plate and delivers an appropriate signal to a control 
device in order to regulate the rotational speed of the feed roll. 
What is perceived to be a shortcoming in this prior art system resides in 
the fact that the measurement of the density of the fiber batt occurs 
prior to entry thereof between the trough-like feed plate and the feed 
roll. This too early or incipient fiber density sensing operation allows 
for variations in the density of the fiber batt to still occur up to the 
point of entry of the fiber batt between the trough-like feed plate and 
the feed roll. These fiber density variations then no longer coincide with 
or are no longer faithfully represented by the measured values. 
By way of clarification, it is here mentioned that fundamentally a 
trough-like feed plate and a feed plate constitute comparable or the same 
type of elements and a feed cylinder and a feed roll likewise constitute 
comparable or the same type of elements. Therefore in the context of this 
disclosure this equatability, as stated above, should be kept in mind and 
is intended to be encompassed by the disclosure and teachings of the 
invention set forth herein. 
The previously mentioned examples, as already discussed, relate to 
important but not however all of the preconditions or prerequisites for 
the uniformity or evenness of a mass of fiber material, such as a web or 
sliver, delivered by a textile machine. 
A likewise essential precondition or prerequisite for the automatic 
compensation or evening of irregularities in a mass of fiber material, 
such as a fiber sliver, particularly in the case of a card or carding 
machine resides in the fact that the delivered mass of fiber material is 
controlled or checked in order to determine fiber loss between the point 
of infeed of the mass of fiber material, in the case of the card, the batt 
or lap, and the condensing of the fiber web at the outlet of the card. 
The already heretofore mentioned German Patent No. 2,912,576, discloses and 
illustrates the combination of the already discussed compensation or 
evening of the infed fiber batt or lap, in conjunction with the control or 
checking of the fiber sliver at the outlet of the card or the drafting 
arrangement. However, this combination is likewise associated with the 
drawbacks heretofore considered in conjunction with such patent. 
SUMMARY OF THE INVENTION 
Therefore, with the foregoing in mind it is a primary object of the present 
invention to provide a new and improved method of, and apparatus for, 
automatically compensating density or thickness variations of fiber 
material at textile machines, such as by way of example but not 
limitation, cards, draw frames and the like, in a manner not afflicted 
with the aforementioned drawbacks and shortcomings of the prior art. 
Another and more specific object of the present invention aims at the 
provision of a new and improved method of, and apparatus for, 
automatically compensating density or thickness variations of fiber 
material at textile machines, such as by way of example but not 
limitation, cards, draw frames and the like in a highly reliable and 
accurate manner. 
Yet a further important object of the present invention is to devise a new 
and improved method of, and apparatus for, automatically detecting and 
compensating density or thickness variations of fiber material at textile 
machines, such as by way of example but not limitation, cards, draw frames 
and the like, in a relatively simple yet extremely accurate and reliable 
fashion without having to tolerate the aforenoted drawbacks or 
shortcomings of existing equipment. 
Still a further significant object of the present invention is directed to 
a new and improved method of, and apparatus for, automatically detecting 
and compensating density or thickness variations of fiber material at 
textile machines, such as by way of example but not limitation, cards, 
draw frames and the like, not only in a highly accurate and reliable 
fashion, but without the need for utilizing fiber feed elements which are 
movable relative to one another and which thus distinctly visibly alter 
the size of the nipping zone or region during the fiber density or 
thickness variation detection operation. 
Yet a further prominent object of the present invention aims at providing a 
new and improved method of, and apparatus for, the detection of density or 
thickness variations of fiber material at a textile machine, wherein there 
is utilized during the density or thickness detection or measuring 
operation an essentially invariable size nipping zone or region through 
which the fibrous material moves, so that fluctuations or variations in 
the density or thickness of the infed fibrous material exert forces 
representative or indicative of such density or thickness fluctuations or 
variations in the infed fibrous material and which forces can be reliably 
sensed and detected and signals representative thereof produced as well as 
there being produced signals representative of the density or thickness or 
weight of the mass of fiber material at the outlet of the textile machine, 
and these signals are then fed to a control which serves to essentially 
even or correct such density or thickness fluctuations or variations at 
the inlet of the textile machine to produce a product of uniform density 
or weight per unit length at the outlet of the textile machine. 
A further pertinent object of the present invention aims at providing a new 
and improved method of, and apparatus for, ascertaining and controlling in 
a highly reliable and weight per unit area, of fiber material, such as 
fiber material infed to a textile machine, as well as the weight or 
density of the delivered fiber material, in order to thereby control the 
production of the textile machine so that it delivers a product of 
essentially uniform density. 
Now in order to implement these and still further objects of the invention, 
which will become more readily apparent as the description proceeds, the 
method for detecting and automatically compensating density or thickness 
variations of fiber material at a textile machine, comprises infeeding the 
fiber material to a fiber infeed device having, during the fiber density 
or thickness variation detection operation, a so-to-speak stationary 
nipping zone or gap, in other words, a stationary nipping zone or gap of 
predeterminate and essentially invariable or unchanging size. The fiber 
material or mass is infed through the stationary nipping zone or gap and 
acts upon one of the elements or components of the fiber infeed device 
such that there are obtained signals as a function of the density or 
thickness of the fiber material in the stationary nipping zone or gap. The 
succession of these signals, each of which are dependent upon or 
correlatable to the instantaneous or momentary density or thickness of the 
infed fiber material and which thus are indicative of variations or 
changes of the density or thickness of the infed fiber material, enable 
reliably detecting or sensing such density or thickness variations. At the 
outlet of the textile machine there is sensed or detected the density or 
weight of the delivered mass of fiber material, such as, for instance a 
web or sliver and signals are produced representative thereof. The signals 
representative of the density or thickness variations of the infed mass of 
fiber material and the signals representative of the density or weight of 
the delivered mass of fiber material are fed or delivered to a control or 
control device which processes such signals to derive output signals. 
These output signals act upon a feed roll of the fiber infeed device in 
order to control the rotational speed thereof and thus compensate or even 
out irregularities in the thickness or density of the infed mass of fiber 
material so that there can be obtained at the outlet of the textile 
machine a mass of fiber material, such as a web or sliver, of essentially 
uniform weight or density. 
At this juncture it is to be noted and appreciated that the terms 
"stationary nipping zone or region or gap", or equivalent expressions, as 
used herein are intended to encompass a nipping zone or region or gap 
through which there is infed the fibrous material whose density or 
thickness variations are to be compensated or evened out. Such nipping 
zone or region can be construed to be stationary inasmuch as none of the 
fiber feed elements defining the nipping zone or region, such as the feed 
roll and feed plate are movable relative to or towards and away from one 
another, even though it is to be appreciated that the feed roll is a 
rotatable feed roll but otherwise constitutes a spatially fixed or 
immovable element. Stated in another way, the nipping zone or region is 
defined by two fiber feed elements which form therebetween such nipping 
zone or region which is of essentially invariable or unchanging size 
during the density or thickness variation detection operation. 
Irrespective how the nipping zone or region is defined, what is important 
is that during the time that there occurs the detection of the density or 
thickness variations of the infed fiber material the elements defining or 
bounding such nipping zone or region do not move relative to one another 
to alter the size or dimensions of the nipping zone or region as is 
contemplated in prior art systems typically as described heretofore, where 
there is intentionally detected through the provision of suitable 
expedients alterations or variations in the actual size of the nipping 
zone or region by sensing or detecting discernible movements of one of the 
elements defining or bounding the nipping zone or region relative to the 
other element. 
In a preferred embodiment of the method the fiber infeed means utilizes a 
stationary or spatially fixed but rotatably driven feed roll, in other 
words a feed roll which is simply driven to perform rotational movements 
but cannot otherwise alter its posture or spatial orientation. This 
stationary and rotatable feed roll coacts with a feed plate, which 
although preferably pivotably mounted, is in fact and must be immobile or 
stationary during the actual detection of the fiber density or thickness 
and variations thereof of the throughpassing or infed fiber material in 
order to obtain useful measuring signals. The immobility of the feed plate 
is imparted thereto by, for instance, continually or continuously biasing 
such feed plate against a stop or abutment so that during the 
afore-explained detection operation this feed plate constitutes a 
stationary feed plate. There is thus formed the aforenoted stationary or 
essentially invariable or fixed-size or unchanging size nipping zone or 
region through which the infed fiber material moves. In a preferred 
embodiment, the throughpassing or infed fiber material exerts forces upon 
the immobile feed plate during the fiber thickness sensing or detection 
operation and these forces are sensed or detected at appropriate measuring 
or sensing elements, typically strain gauges, which produce signals 
representative or indicative of the density or thickness fluctuations or 
variations of the infed fiber material. 
In order to even out or compensate the density or thickness of the fiber 
material at the infeed to the textile machine and thus the density or 
weight of the product delivered by the textile machine, the thus obtained 
signals along with the signals obtained as a function of the density or 
weight of the delivered mass of fiber material at the outlet of the 
textile machine are inputted to a suitable control device which produces a 
control signal or signals for appropriately controlling the rotational 
speed of the spatially fixed but rotatable feed roll to even out the 
detected density or 
Other possibilities exist, as will be explained more fully hereinafter, to 
detect variations in the density or thickness of the infed fiber material 
by using the unique essentially invariable or unchanging size nipping zone 
or region defined by the coacting feed elements. For instance, there can 
be sensed alterations in the throughflow of a pressurized fluid medium, 
typically air flowing through the compressed fiber material in the nipping 
zone or region, which are then indicative of variations in the density or 
thickness of the throughflowing or infed fiber material. Another technique 
which can be beneficially used is to detect, with the aforedescribed 
essentially invariable or unchanging size nipping zone or region, the 
forces exerted by the throughpassing fiber material upon one or more force 
measuring cells provided at one of the feed elements, thus providing an 
indication of alterations in the density or thickness of the 
throughpassing or infed fiber material. 
As already heretofore explained, the invention is not only concerned with 
the aforementioned method aspects but also pertains to a new and improved 
construction of apparatus for detecting and compensating density or 
thickness variations of the fiber material at a suitable textile machine, 
such as typically although not exclusively, a carding machine or card. To 
that end the density or thickness detection and compensation apparatus of 
the present development is manifested by the features that there is 
provided a fiber infeed means or device to which there is delivered the 
fiber material. The fiber infeed means comprises two coacting fiber infeed 
elements or fiber infeed components. One of the fiber infeed elements or 
fiber infeed means can be constituted by at least one driveable or driven 
rotatable feed roll for delivering the fiber material to a downstream 
located textile machine. Coacting with the at least one driveable or 
driven feed roll is a fiber feed plate. The at least one driveable or 
driven fiber feed roll and the feed plate, during the fiber density or 
thickness detection operation, define therebetween a stationary nipping 
zone or region, in other words, a nipping zone or region of essentially 
invariable or unchanging size, through which the infed fiber material 
passes. The throughpassing or infed fiber material acts upon at least one 
of the fiber infeed elements or components in the stationary or 
essentially invariable size nipping zone or region such that the 
variations in the density or thickness of the infed fiber material passing 
therethrough are detected by suitable measuring or sensing elements 
responsive to the action of the throughpassing or infed fiber material 
upon such one fiber infeed element or component which together with the 
other fiber infeed element or component forms the stationary or 
essentially invariable or unchanging size nipping zone or region. 
At the outlet or delivery side of the textile machine, there is detected or 
measured the density or weight (mass) of the delivered mass of fiber 
material, such as in the case of a card, the web or sliver, and there are 
produced signals representative of such density or weight. A conventional 
device can be used for this purpose, for instance as disclosed in the 
aforementioned European Patent No. 0,078,393 and the cognate U.S. Pat. No. 
4,539,729. 
The signals representative of the density or thickness variations in the 
throughpassing or infed fiber material along with the signals 
representative of the density or weight of the delivered mass of fiber 
material at the outlet or outlet side of the textile machine are delivered 
to a suitable control device or control which produces appropriate control 
signals for controlling the rotational speed of the driven but stationary 
feed roll so as to even out or compensatingly control the detected density 
or thickness variations of the infed fiber material. 
According to a preferred embodiment of the invention the one fiber infeed 
element or component is constituted by a preferably pivotable feed plate 
which, however, during the actual fiber density or thickness detection 
operation, is continually or continuously urged against a stop or abutment 
by the action of the throughpassing or infed fiber or fibrous material. 
This throughpassing or infed fibrous material exerts forces on the 
immobile feed plate which are sensed by suitable measuring or sensing 
elements, typically strain gauges, to produce signals representative or 
characteristic of the density or thickness variations in the 
throughpassing or infed fiber material which moves through the stationary 
or essentially invariable or unchanging size nipping zone or region. 
It should be appreciated that through the practice of the method and 
through the provision of apparatus constructions useful for the 
performance thereof, there can be reliably detected with extreme accuracy 
the density or thickness and variations thereof of the fiber material 
infed into the textile machine without being confronted with the 
aforementioned drawbacks or shortcomings of the prior art and there can be 
automatically compensated such density or thickness variations so as to 
produce an extremely uniform product having an essentially uniform weight 
or density at the outlet of the textile machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Describing now the drawings, it is to be understood that for purposes of 
simplification of the illustration thereof, only enough of the apparatus 
for automatically compensating the density or thickness variations of 
fiber material at a suitable associated textile machine and details of the 
construction of such associated textile machine, have been portrayed in 
the drawings as are needed to enable those skilled in the art to readily 
understand the underlying principles and concepts of the present 
development. Turning attention now to FIG. 1 of the drawings, there has 
been illustrated therein only by way of example and not limitation, as a 
possible type of textile machine with which the density variation 
compensating apparatus can be beneficially used a carding machine or card 
1. This carding machine or card 1 will be seen to comprise, looking from 
the left to the right of the showing of FIG. 1, at the card inlet a fiber 
processing means, here a fiber infeed means or device, generally indicated 
in its entirety by reference numeral 2, and various embodiments of which 
will be discussed in detail in conjunction with other figures of the 
drawings, as well as a licker-in cylinder or roll 3, a main carding 
cylinder 4 provided with suitable carding flats 5 or the like, a doffer 
cylinder 6, also referred to in the art as a doffer roll, and a fiber web 
condensing unit or condenser 7 for forming a card sliver 8. 
The fiber infeed means or fiber infeed device 2 comprises two coacting 
fiber feed or infeed elements or components 9 and 10. One of these 
coacting fiber feed elements 9 and 10, here the fiber feed element 9, 
comprises a driveable or driven rotatable feed roll or roller 9, also 
referred to sometimes in the art as a feed cylinder. The other fiber feed 
or infeed element 10 coacting with the rotatable feed roll 9, is here 
constituted by a fiber feed plate 10, also sometimes referred to in the 
art as a trough-plate or trough-like feed plate. This fiber feed plate 10 
is pivotably mounted for swivel or pivotal motion about a pivot shaft or 
axis 11. It is to be understood, however, that during the actual detection 
of the density or thickness variations in the density or thickness 
--hereinafter usually simply conveniently referred to as density 
variations--of the infed fiber material 15, here shown as a fiber batt or 
lap, the pivotably mounted feed plate 10 is in fact stationary or 
immobile. This will be explained shortly in greater detail. 
The feed roll 9, although constituting a rotatably or rotatable driven feed 
roll, is otherwise stationarily or fixedly arranged, in other words is 
spatially fixed in relation to the feed plate 10 during the detection of 
the fiber density variations of the infed or incoming fiber batt or lap 
15. Since, as explained, the feed plate 10 is stationary during the actual 
fiber density variation detection operation there is provided a suitable, 
preferably adjustable stop or abutment 12 against which this pivotable 
feed plate 10 is forced, for instance, by the incoming batt or lap 15 
during the measurement of the density variations of such incoming or infed 
batt or lap 15. This stop or abutment 12 can be constituted, for instance, 
by a suitable adjustment screw or equivalent element against which there 
is firmly contactingly forced the feed plate 10 in a direction away from 
the feed roll 9 by the throughpassing or infed batt or lap 15. 
In this way there is formed a stationary fiber throughpass zone or nipping 
zone or region 23, in other words a nipping zone or region 23 of 
essentially invariable or unchanging size, between the thus or otherwise 
appropriately . immobilized feed plate 10 and the rotatable but spatially 
fixed feed roll 9 during throughpassage of the batt or lap 15 between this 
stationary feed plate 10 and the rotatably driven feed roll 9. Stated 
another way, the outer surface or circumference 9a of the rotatably driven 
but spatially fixed feed roll 9 forms a first nipping surface which coacts 
with the confronting surface 10a of the stationary or immobilized feed 
plate 10 which forms a stationary nipping surface. The feed plate 10 is 
only here pivotably mounted to allow it to move towards the rotatably 
driven feed roll 9 in the event of depletion of the incoming batt or lap 
15 or should the same fall below a predeterminate minimum thickness, in 
which event the otherwise immobilized feed plate 10 then can move, 
downwardly in the showing of FIG. 1, towards the rotatably driven feed 
roll 9 against a further stop or abutment, such as the stop or abutment 27 
depicted in FIGS. 2 and 4, as will be explained more fully hereinafter. 
This stationary nipping zone or region 23 is here shown to possess, for 
instance, a substantially wedge-shaped converging configuration in the 
direction of travel of the mass of fiber material 15. 
The rotatably driven feed roll 9 can be driven by any suitable drive means 
or drive motor, for instance, a gearing or transmission motor 13 as is 
well known in this technology. 
During operation of the equipment or system, the fiber infeed means or 
device 2 has delivered thereto the fiber material, here the batt or lap 15 
as the same moves along an infeed plate or plate member 14 or equivalent 
fiber material supporting structure. Due to the rotation of the rotatably 
driven feed roll 9 in the rotational direction U, and as is well known in 
this art, the fiber batt or lap 15 is delivered in the form of a 
compressed batt or lap to the licker-in cylinder or roll 3 which rotates 
at a appreciably greater rotational speed. 
The fiber material which is processed between the main carding cylinder 4 
and the carding flats 5 is removed by the doffer cylinder or roll 6 and 
delivered to the fiber web compaction or condensing device 7 in which the 
fiber web is compacted or condensed to form a card sliver 8. The ratio of 
the circumferential velocity of the doffer cylinder 6 with respect to the 
circumferential velocity of the rotatably driven feed roll 9 constitutes 
the so-called drafting ratio of the carding machine or card. 
Directly after the aforementioned compaction or condensing device 7, viewed 
in the direction of travel of the fiber sliver, a measuring device 110, 
for instance of the type disclosed in the aforementioned European Patent 
No. 0,078,393 and the cognate U.S. Pat. No. 4,539,729, to which reference 
may be readily had, determines or detects the density or weight (mass) of 
the fiber sliver and delivers to a control or control device 17 by means 
of the line or conductor 111 signals representative or indicative of the 
density or weight of the delivered fiber sliver 8. 
Moreover, in the exemplary embodiment under discussion due to the initial 
infeed of the fiber batt or lap 15 the feed plate 10 is pivoted away from 
the feed roll 9 to such an extent until this feed plate 10 firmly abuts 
against the stop or abutment 12, here depicted as the adjustable stop or 
abutment screw or equivalent structure. This position of the feed plate 10 
where it is essentially immobilized against any further upward movement, 
will be conveniently referred to as the operating position of the thus 
immobilized or stationary feed plate 10. 
With the aid of the adjustable abutment screw 12 or the like there can be 
determined the desired degree of compaction of the batt or lap 15 which is 
located between the thus immobilized or stationary feed plate 10 and the 
rotatably driven but spatially fixed feed roll 9, in other words the fiber 
batt compaction in the nipping zone or region 23. Through the provision of 
the adjustable stop or abutment 12 the desired size or dimension of the 
nipping zone or region 23 can be initially set in accordance with the 
nature and properties of the mass of the fiber material which is intended 
to be processed. 
The nipping or clamping action which is exerted by the nipping surfaces 9a 
and 10a of the feed roll 9 and stationary feed plate 10, respectively, in 
the essentially invariable or unchanging size nipping zone or region 23 
located between these elements 9 and 10 and extending over the machine 
cross-width or length of such elements 9 and 10 produces, as will be 
described more fully hereinafter, detectable or measurable values 
representative of the density or thickness variations of the infed batt or 
lap 15 at the fiber infeed means 2, by means of which there can be 
continuously obtained a signal or sequence of signals 16, each 
representative of the instantaneous or momentary density or thickness of 
the so-to-speak "clamped" fiber batt or lap 15. 
The signal 16 or, as the case may be, an average value of each of the thus 
momentarily obtained signals 16, for instance derived at opposite ends of 
the feed plate 10 as will be considered more fully hereinafter, is fed to 
the control device or control 17 together with a predeterminate desired 
set or reference value signal 18 for the desired density or weight of the 
delivered sliver 8 or fiber material, a rotational speed signal 19 
representative of the rotational speed of the doffer roll 6 and a 
rotational speed signal 20 representative of the rotational speed of the 
gearing or transmission motor shaft 21 of the drive motor 13 as well as 
the previously discussed signals appearing on the line or conductor 111 
representative of the actual density or weight (mass) of the delivered 
fiber sliver 8. The rotational speed signal 19 represents the rotational 
speed of the doffer roll 6 and is a desired preset signal as is well known 
in this art. 
The control device or control 17 appropriately processes the aforementioned 
inputted signals so as to derive output or control signals 22, by means of 
which the rotational speed of the gearing or transmission motor 13 can be 
controlled in accordance with the deviations in the thickness or density 
of the mass of fiber material 15 in the essentially invariable size 
nipping zone or region 23 and the deviations of the outputted sliver mass 
or density determined by the device or apparatus 110 in such a manner that 
the density of the fiber sliver 8 or the like, departing from the card 1 
is essentially uniform, in other words, there is delivered a product of 
substantially uniform weight per unit length. 
Although, as stated, control devices for controlling the rotational speed 
of a driven feed roll are well known in this art there will be explained, 
by way of example, and not limitation, a possible construction of the 
essential components of the control device or control 17. This control 
device 17 may basically comprise a commercially available microcomputer, 
type 990/100MA, readily available from the well known firm Texas 
Instruments and equipped with a required number of EPROM's likewise 
commercially available under the type designation TMS27l6 from Texas 
Instruments for programming desired control functions. The control device 
17 also contains a commercially available regulator procurable under the 
designation type D 10 AKN RV 419D-R from the West German firm AREG 
Corporation, located at Gemrigheim, West Germany, this regulator 
amplifying the signals delivered by the microcomputer so as to produce the 
output or control signals 22 as a function of the rotational speed signal 
20 delivered thereto. These output or control signals 22, as explained, 
serve for the continuous control and regulation of the rotational speed of 
the feed roll 9. Since in the depicted arrangement, the control device 17 
takes into account the actual density or weight of the card sliver 8 at 
the output or delivery side of the carding machine or card 1, the system 
in question is a so-called closed loop control system with error feed 
forward. Also prior known closed loop systems with error feed forward, but 
with a quite different fiber infeed device for detecting thickness 
variations or fluctuations of the infed fiber material, have been 
previously used on commercially available Rieter cards of the Assignee of 
the instant application, known in the market under the designation "Rieter 
C-4 card". Also as will be evident to those skilled in the art there could 
be used an electrical control instead of an electronic control. 
Continuing, it should be evident that the nipping zone or region 23 is 
defined by the coaction of the feed roll 9 and the feed plate 10 in that 
in this wedge-shaped converging nipping zone or region 23 the infed batt 
or lap 15 is compressed from its original thickness D to a lesser 
thickness which such compressed batt or lap 15 possesses directly prior to 
departure from the nipping zone or region 23. The nipping zone or region 
23 thus terminates at a location of narrowest size at the region of the 
edge or nose of the feed plate 10, designated as the fiber delivery or 
release edge or nose or nose member 24, where the batt or lap 15 is no 
longer clamped or nipped by the stationary feed plate 10. 
The direction of rotation of each of the rotatably driven feed roll 9, the 
licker-in cylinder 3, the main carding cylinder 4, and the doffer cylinder 
6 have each been conveniently designated by the associated arrow U. The 
fiber material travels through the carding machine or card 1 in accordance 
with the direction of rotation U of the aforementioned individual 
components or elements 9, 3, 4 and 6. 
Now in FIG. 2, there has been illustrated on an enlarged scale and in 
somewhat greater detail the fiber infeed means or device 2 of the textile 
machine, namely the exemplary card 1 of the arrangement of FIG. 1, 
wherefore the same elements or components have been generally conveniently 
designated with the same reference characters. 
By inspecting FIG. 2 it will be apparent that the there depicted pivot 
shaft or axis 11 for the feed plate 10 is mounted in a stationary bearing 
housing 26 which is part of the machine housing 25, only schematically 
depicted in such FIG. 2. It is of course to be appreciated that the feed 
plate 10 is preferably mounted at opposite ends or sides thereof at a 
related pivot shaft or journal 11 (see also FIGS. 31 and 33) in an 
associated stationary bearing housing 26 at each such opposite end of the 
feed plate 10, but as shown in the drawings by way of example a single 
throughpassing pivot shaft 11 also can be used. 
Furthermore, at the machine housing 25 there is secured a stop or impact 
member or abutment 27, as previously mentioned, which prevents the feed 
plate 10, when the fiber batt or lap 15 has depleted or has a thickness 
below a permissible thickness, from dropping onto and undesirably coming 
into contact with the rotatably driven feed roll 9. 
Equally apparent in the showing of FIG. 2 is a mounting or support element 
28 for receiving the preferably adjustable stop or abutment member 12, 
here the adjusting or adjustment screw 12. The drive motor 13, here the 
gearing or transmission motor, for the rotatably driven feed roll 9 is 
likewise secured at the machine housing 25, as has been shown in FIG. 2. 
In FIG. 3 there is depicted a variant embodiment of the fiber infeed means 
or device 2.1 from that shown with reference to FIGS. 1 and 2 previously 
discussed, so that again the same or analogous elements or components have 
been generally conveniently designated with the same reference characters. 
This modified construction of the fiber infeed means or device 2.1, as 
will be observed by inspecting FIG. 3, will be seen to comprise a feed 
plate 29 having a nipping surface 29a and which, however, in this case is 
arranged below the rotatable driven feed roll 9. The feed plate 29 is 
pivotably mounted by means of a pivot shaft or axis 31 in a bearing 
housing 30 secured at the machine housing 25. 
In this case, the stop or abutment 32 is constituted by an adjusting or 
adjustment screw engaging with the lower face or surface 29b of the feed 
plate 29. This adjusting or adjustment screw 32 or equivalent structure 
limits the pivotal movement of the feed plate 29 in a direction away from 
the coacting feed roll 9. A further stop or abutment 33 prevents the feed 
plate 29 from moving in the direction towards the feed roll 9 and 
undesirably coming into contact with this feed roll 9. This possible 
motion of the feed plate 29 upwardly towards the feed roll 9 can be 
precipitated by the compression or pressure spring 34 which is here 
likewise provided as a safety feature to urge the feed plate 29 towards 
but not into contact with the feed roll 9 in the event of depletion or 
undesirable thickness reduction of the fiber material 15. 
The adjusting or adjustment screw 32 is mounted by means of a suitable 
mounting or support element 35 carried by the machine housing 25. Equally, 
the compression or pressure spring 34 is supported by a mounting or 
support element 36 likewise carried by the machine housing 25. 
The aforementioned stop or abutment 33, in this case, is constituted by the 
end surface 33a of the fiber infeed plate 37 which likewise is 
appropriately attached at the machine housing 25. In this embodiment the 
region of the nipping zone or region 23.1 corresponds to the region of the 
nipping zone or region 23 depicted with reference to FIGS. 1 and 2. 
In the description to follow there will be considered with reference to 
further figures of the drawings the measuring or sensing expedients or 
means which can be advantageously employed in order to generate the 
signals 16 delivered by the fiber infeed means or the fiber infeed device 
2 o 2.1 heretofore considered. 
At this point it is remarked that FIGS. 4, 8, 12 16, 20 and 24 depict 
elements of the fiber infeed means or device 2 of the arrangement of FIG. 
2, whereas FIGS. 6, 10, 14, 18 and 22 depict elements of the fiber infeed 
means or device 2.1 of the modified embodiment of FIG. 3. Therefore, in 
the aforementioned figures of the drawings there have again been generally 
conveniently used the same elements to designate the same or analogous 
components. 
From the illustration of FIG. 5, which is a top plan view of the 
construction of fiber infeed means or device depicted in FIG. 4, it will 
be seen that there is provided the feed plate 10, the pivot shaft or axis 
11 and the bearing housing 26 as well as a second bearing housing 26.1 at 
the opposite end or side of the feed plate 10 which likewise receives the 
associated pivot shaft or axis 11, as has been previously considered when 
explaining the arrangement of FIG. 2. In the arrangement shown by way of 
example in FIG. 5 there is depicted a single throughgoing pivot shaft 11, 
by way of example. 
The feed plate 10 possesses two bearing brackets or collars 38 by means of 
which the feed plate 10 can be pivotably mounted at its opposite ends at 
the pivot shaft or axis 11. In the intermediate space between the bearing 
brackets or collars 38 and the bearing housing 26 and 26.1, respectively, 
the pivot shaft or axis 11 is provided with a respective surface 39, as 
also particularly well seen by referring to FIGS. 32 and 33. At each such 
surface 39 located at opposed ends of the feed plate 10 there is mounted 
an associated sensing or measuring element, here a strain gauge 90 (see 
FIGS. 32 and 33). These strain gauges 90 are arranged in such a manner 
that the strain gauges 90 arranged at opposite ends of the feed plate 10 
each generate a signal in accordance with the magnitude of a force F (as 
shown in FIGS. 4, 31 to 33) which momentarily arises during the density or 
thickness variation detection operation due to the action of the infed 
fibrous material, such as the batt or lap 15 acting upon the feed plate 
10. Both of these derived signals detected or sensed at the strain gauges 
90 then can be conventionally converted in an appropriate average or mean 
value former so as to obtain the previously mentioned signals 16 
representative of the momentary density or thickness variations or 
fluctuations of the infed fiber material 15. 
It is to be understood the force F is composed of two force components, and 
specifically, on the one hand, a force component which emanates from the 
compression or pressure forces generated by the so-to-speak spring-action 
of the fibrous material, for instance, the infed fiber batt or lap 15, in 
the nipping zone or region 23 between the feed plate 10 and the feed roll 
9 and, on the other hand, a force component which results from the 
frictional forces arising in the nipping zone or region 23 by virtue of 
the movement of the throughpassing fiber material. 
The optimum direction of the force F can be determined empirically and this 
is possible by determining, for instance, at what orientation of the 
strain gauges 90 the same will generate the greatest response signal. It 
is, however, here noted that an approximation to such optimum direction is 
generally sufficiently accurate for density or thickness variation 
detection purposes. It has been found that an orientation of the strain 
gauges 90 so as to essentially lie in a horizontal plane as shown in FIG. 
32 is quite advantageous. 
At this point reference will be made to FIG. 31 which further illustrates 
that the force F which acts upon the related pivot shaft or axis 11 (or 
pivot journal) corresponds to a force F.sub.H which need not be, however, 
located in the same plane as the force F. This force F.sub.H, in turn, 
constitutes a component of the resultant force F.sub.R resulting from the 
aforenoted compression or pressure and frictional forces exerted by the 
fiber or fibrous material upon the feed plate 10. 
By way of example, there has been depicted in a somewhat enlarged scale in 
FIGS. 32 an 33 and thus in greater detail than in the illustration of, for 
instance, FIG. 5, that the surfaces 39 which are provided with the strain 
gauges 90 can each constitute, for instance, a planar base surface of a 
related first bore 91 and by means of a further or second bore 92, 
arranged in mirror image relationship to the aforementioned first bore 91, 
there can be formed a web 93 constituting the weakest location of the 
associated shaft or journal defining the pivot shaft or axis 11 of the 
related feed plate 10. The strain gauges 90 mounted in the aforementioned 
manner are commercially available and, for instance, obtainable from the 
Swiss firm REGLUS Corporation, located at Adliswil, Switzerland. 
Furthermore, in FIG. 33 there have been illustrated the compensation or 
reaction force F.sub.K1 and F.sub.K2 which prevail by virtue of the force 
F. The forces F and F.sub.K1 act in such a manner that the strain gauges 
90 are deformed essentially in accordance with the shear or transverse 
forces appearing at the related web 93. The force F.sub.K2 is applied to 
prevent the occurrence of an undesired turning moment on the feed plate 
10. The forces which have been illustrated in FIG. 33 have been portrayed 
simply for explanatory purposes and are not drawn to scale or proportion 
or in the precise direction in which they act. 
It will be recognized that the density or thickness variations of the infed 
fiber or fibrous material, such as those of the batt or lap 15 of the 
exemplary arrangement of, for instance, FIGS. 1, 2 and 4 or for that 
matter that of the fibrous material infed into the fiber infeed means or 
device 2.1 of FIG. 3 heretofore described, are detected by employing a 
force measuring technique. This is possible because, during operation, the 
one coacting fiber feed element, such as the feed plate 10 or 29, is held 
stationary with reference to the other coacting fiber feed element, namely 
the feed roll 9 so as to form a stationary nipping zone or region 23 or 
23.1, in other words, a nipping zone or region which does not vary in 
size. The fibers act upon the stationary feed plate 10 or 29 associated 
with the force measuring elements, here the strain gauges 90, so that 
depending upon the variation in density of the fiber material 15 infed 
through the stationary nipping zone or region 23 or 23.1, such density 
variations of the infed fiber or fibrous material 15 can be reliably and 
exceedingly accurately detected and there can be generated the signals, 
such as the signal 16 shown in FIGS. 1 and 4 representative of the density 
variations of the fibrous material 15. This force measuring technique is 
utilized throughout a great many of the other embodiments herein 
described. At this point it is specifically mentioned that the use of such 
force measuring technique is employed in the embodiment of FIGS. 6 and 7 
now to be described. 
Thus, attention now is directed to this modified embodiment of the fiber 
infeed means or devices as depicted in such FIGS. 6 and 7. FIG. 7 shows in 
top plan view the arrangement of FIG. 6, and specifically portrays the 
feed plate 29, the pivot shaft or axis 31 and the bearing housing 30 as 
well as a second bearing housing 30.1 which likewise receives the pivot 
shaft 31. Likewise, the feed plate 29 will be seen to comprise two bearing 
brackets Or collars 40 which receive the pivot shaft 31. In analogous 
fashion as has heretofore been described with reference to FIGS. 4 and 5, 
and also FIGS. 31 to 33, the pivot shaft 31 contains at the intermediate 
spaces between the bearing brackets 40 and the bearing housing 30 and 
30.1, respectively, a respective surface 39 for the reception of an 
associated strain gauge, like the strain gauges 90 depicted in FIGS. 32 
and 33 but not here specifically shown to simplify the illustration. 
Just as was heretofore the case, also with the embodiment of FIGS. 6 and 7 
the strain gauges are arranged in such a manner that each of these strain 
gauges generates a respective signal corresponding to the magnitude of the 
force F.1 (FIG. 6) which during operation of the system acts upon the feed 
plate 29 of the fiber infeed means or device, and again both of these 
generated signals are converted, for instance, in an average or mean value 
former to produce the signals 16 which are representative of density 
fluctuations of the infed fibrous material. It is also here mentioned that 
the force F.1 is generated in analogous fashion to the force F described 
with reference to the embodiments of FIGS. 4 and 5. Here also the optimum 
direction of the force F.1 is determined empirically as previously 
explained, and it is likewise usually sufficiently accurate to have such 
force direction simply approach the optimum direction. 
In the embodiments depicted in FIGS. 8 and 9, 12 and 13, 16 and 17, 20 and 
21 as well as 24 and 25, with the exception of the measuring or sensing 
means for deriving or generating each signal 16, there have been generally 
illustrated the same elements or components as illustrated with reference 
to the embodiment of FIGS. 4 and 5. Hence once again the same reference 
characters have been used for designating the same or analogous components 
as a matter of convenience. The same also holds true for the embodiments 
of FIGS. 10 and 11, 14 and 15, 18 and 19 as well as 22 and 23 with respect 
to the analogous elements or components depicted in the embodiment of FIG. 
3 and that of FIGS. 6 and 7. 
The measuring means or measuring or sensing expedients depicted in the 
variant embodiment of FIGS. 8 and 9 constitute a force measuring cell 41 
or equivalent structure which is operatively associated with or 
constitutes a component of the stop or abutment 12, again depicted as the 
adjusting or adjustment screw or equivalent structure, such that this 
force measuring cell 41 delivers or generates a signal 16 which 
corresponds to the magnitude of the force F.2 (FIG. 8) applied by the 
fibers against the stationary feed plate 10 which abuts the adjusting or 
adjustment screw 12. This force F.2 constitutes a resultant force of the 
forces generated, during operation of the system, by the fiber material, 
like the fiber batt or lap 15 shown in FIG. 1 but not particularly 
depicted in FIG. 8, which is present in the region of the aforementioned 
essentially invariable or unchanging size nipping zone or region 23. This 
resultant force F.2 acts in the direction of the lengthwise axis of the 
adjusting or adjustment screw 12. This adjusting or adjustment screw 12 
is, for instance, here arranged at the central region of the machine 
cross-width or length L of the feed plate 10, as will be recognized by 
inspecting FIG. 9. Furthermore, by again reverting to FIG. 8 it will be 
seen that the essentially horizontal distance H of the aforementioned 
lengthwise axis of the adjusting or adjustment screw 12 to the fiber 
transfer nose or nose member or end portion 24 of the feed plate 10 is not 
particularly critical, although it is desirable to strive for or attain as 
small as possible spacing H. 
The same observations hold true for the force measuring cell 41.1 which is 
operatively associated with or a part of the adjusting or adjustment screw 
32 of the modified arrangement of FIGS. 10 and 11. Here also a force F.3, 
analogous to the force F.2 of the embodiment of FIGS. 8 and 9, acts upon 
the force measuring cell 41.1. Analogous to the prior described embodiment 
of FIGS. 8 and 9, in the arrangement of FIGS. 10 and 11, the adjusting or 
adjustment screw 32 acts, for instance, at the center of the machine 
cross-width or length L of the feed plate 29, and is arranged, as viewed 
in FIG. 10, at a horizontal spacing or distance H.1 from the fiber 
deflection nose or edge or end portion 44 of this feed plate 29 and with 
respect to the force F.3 which acts in the direction of the lengthwise 
axis of the adjusting or adjustment screw 32. 
FIGS. 12 and 13 as well as FIGS. 14 and 15, respectively, each depict a 
variant embodiment as concerns the use of the force measuring cells for 
determining the forces generated during operation of the fiber infeed 
system owing to the density or thickness variations of the fiber material 
at the region of the wedge-like nipping zone or region, like the nipping 
zones or regions 23 and 23.1, respectively, depicted in FIGS. 2 and 3 
(although not particularly referenced in each of FIGS. 12 and 14). 
The feed plate 10 of the embodiment of FIGS. 12 and 13 possesses at the end 
face or surface 42 which confronts the licker-in cylinder or roll 3 (FIG. 
2) a continuous groove or slot 43. This continuous groove or slot 43 
extends over the entire machine cross-width or length L (FIG. 13) of the 
feed plate 10 and has a depth T and a height B (FIG. 12). The groove or 
slot height B is selected such that the force measuring cells 41.2 can be 
inserted essentially free of play into the groove or slot 43 and can be 
fixedly retained therein in the position depicted in FIGS. 12 and 13. 
During operation, the fiber material, such as the batt or lap 15 shown in 
FIG. 1 but not particularly depicted in FIG. 12 and located in the region 
of the nipping zone or region, like the essentially invariable size 
nipping zone or region 23 of FIG. 2 but not here specifically referenced, 
between the feed plate 10 and the feed roll 9 exert forces which have the 
tendency to deform or flex a part or portion 60 of the feed plate 9 in the 
direction R about an inner groove edge 61. This part or portion 60 of the 
feed plate 9 is located between the continuous or through-going groove or 
slot 43 and the fiber release or delivery edge or nose or nose member 24 
of the feed plate 10. From these forces there results a force F.4 which is 
effective over the entire machine cross-width or length L of the feed 
plate 10 and which generates an appropriate signal in each of the force 
measuring cells 41.2. The signals of the individual force measuring cells 
41.2 are advantageously averaged or meaned in a suitable average or mean 
value forming circuit so as to produce each of the aforedescribed signals 
16. By appropriately selecting the number and arrangement of the force 
measuring cells 41.2 they each can receive a proportional or 
predeterminate part of the applied forces emanating from the 
throughpassing mass of fiber material. 
The variant embodiment depicted in FIGS. 14 and 15 functions, as far as the 
generation of each of the signals 16, essentially like the embodiment 
described with reference to FIGS. 12 and 13. Therefore, the elements 
required for generating each signal 16 have been conveniently designated 
in FIGS. 14 and 15 with the same reference characters as were employed for 
the embodiment of FIGS. 12 and 13, with the exception of the force F.5 
which, by virtue of the different manner of fiber transfer at the nose or 
nose member 44 of the feed plate 29 to the licker-in cylinder 3, possesses 
a different magnitude than the force F.4 of the arrangement of FIG. 12 in 
which the fibers are transferred in so-to-speak the same direction or 
unidirectionally from the feed roll 9 to the licker-in cylinder 3. This 
unidirectional fiber transfer arises by virtue of the fact that the feed 
roll 9 and the licker-in cylinder 3 exhibit the same direction of movement 
or rotation (here counterclockwise) at the fiber transfer location (see 
FIG. 1). However, other factors can play a role in the generation or 
formation of the force component F.5, such as for example the form of the 
feed plate 10 or 29, as the case may be, at the region of the nipping zone 
or region, which, as previously stated would be designated by reference 
characters 23 or 23.1, respectively, like indicated in FIGS. 2 and 3, as 
well as the spacing of the groove edge 61 from the surface 10a or 29a of 
the feed plate 10 or 29, respectively, guiding the fiber material 15. It 
is to be specifically understood that the invention is not limited in any 
way to the number and arrangement of the force measuring cells depicted in 
FIGS. 13 and 15. It should be understood that, for instance, depending 
upon the strength of the part of the feed plate 10 or 29 extending from 
the continuous groove 43 up to the fiber release edge or nose 24 (FIG. 12) 
or to the nose or nose member 44 (FIG. 14) there can be provided one, two 
or a greater number of force measuring cells 41.2. 
In the embodiment of FIGS. 16 and 17 the measuring means or expedients 
comprise three force measuring cells 41.3. These force measuring cells 
41.3 are arranged in a groove or slot 45 formed in the feed plate 10 and 
opening at the region or bounding surface of the nipping zone or region, 
like the nipping zone or region designated by reference numeral 23 in 
FIGS. 1 and 2 into such nipping zone or region. The force measuring cells 
41.3 here bear against the base or floor 45a of the groove or slot 45. 
In order to transmit the force components F.6 to the force measuring cells 
41.3, and which force components F.6 act over the entire machine 
cross-width or length L of the feed plate 10 and are generated by the 
fiber material located in the nipping zone or region, the force measuring 
cells 41.3 are here covered by a force transmitting beam or beam member 46 
or equivalent force transmission structure. This force transmitting beam 
or beam member 46 is completely adapted to fully close the associated 
groove or slot 45 and without causing disturbing bending to the form of 
the feed plate 10. The signals which are delivered by the individual force 
measuring cells or units 41.3 are again converted in a conventional 
average or mean value former to produce the respective signals 16 as 
heretofore described. The distribution of the aforementioned force 
measuring cells or units 41.3 in the groove or slot 45 is essentially 
accomplished in the manner depicted in FIG. 17. However, it should be 
understood that the number of force measuring cells or units 41.3 is not 
limited to the three depicted force measuring cells or units 41.3. For 
instance, when using a force transmitting beam or beam member which is 
designed to possess an appropriate strength there can be used only two 
force measuring cells or units 41.3, whereas if a finer or more precise 
detection of the force components over the length L of the feed plate 10 
(FIG. 17) is to be realized, there can be distributively arranged a larger 
number of force measuring cells or units 41.3. 
The measuring means of the embodiment of FIGS. 18 and 19 comprises a 
membrane or diaphragm 47 or equivalent structure which is incorporated 
into or installed at the feed plate 29, a pressure converter or transducer 
48 and a pressure fluid system 49 which interconnects the membrane or 
diaphragm 47 with the pressure converter 48. 
A force component F.7 (FIG. 18) analogous to the force F.6 of the 
embodiment depicted in FIGS. 16 and 17, causes a pressure to be exerted 
upon the membrane or diaphragm 47. As a result, there is transmitted a 
force by means of the pressure fluid system 49 to the pressure converter 
48 and which generates a signal 16 corresponding to the force F.7. 
The measuring means of the embodiment of FIGS. 20 and 21 is predicated upon 
the recognition that upon introducing the fiber material into the 
wedge-shaped converging nipping zone or region between the feed plate 10 
and the feed roll 9, that is to say, in the region of the essentially 
invariable or unchanging size wedge-shaped converging nipping zone or 
region, like the wedge-shaped converging nipping zone or region 23 shown 
in FIG. 2, air will be expelled or expressed out of the fiber material 15, 
such as the batt or lap 15, owing to the increasing constriction or 
narrowing of the wedge-shaped nipping zone or region 23. 
Expulsion or displacement of this air is counteracted by the resistance of 
the batt or lap 15, so that in the batt or lap 15 there arises an 
increasing excess pressure in the direction of the fiber transfer edge or 
region or nose 24. The resistance to air flow is representative of the 
momentary or instantaneous density or thickness of the fiber material, 
here the batt or lap 15, and the amount of air which is to be expelled. 
This excess pressure is detected by the measuring means depicted in the 
embodiment of FIGS. 20 and 21, in that a measuring groove or slot or 
channel 50 is appropriately formed in the feed plate 10. This measuring 
groove or slot 50 is connected within the confines of the feed plate 10 by 
means of a pressure line or conduit 51 and a pressure line or conduit 52 
connected with the feed plate 10 to a pressure converter or transducer 53. 
This pressure converter or transducer 53 converts the excess pressure 
determined at the measuring groove or slot 50 into the signal 16. 
As will be apparent from the illustration of FIG. 21 the measuring groove 
or slot 50 is not continuous over the entire machine cross-width or length 
L of the feed plate 10, that is to say, the length L.1 of the measuring 
groove or slot 50 is shorter than the length L of the feed plate 10. Thus, 
as far as the measuring groove or slot 50 is concerned, such constitutes a 
measuring groove or slot located in the region of the nipping zone or 
region 23 and which is only open towards such nipping zone or region. 
As depicted in FIG. 20, the measuring groove or slot 50 forms an acute 
angle .alpha. with an imaginary plane E. This imaginary plane E, as a 
tangential plane, contains the mouth edge 54 of the wall 55 of the 
measuring groove or slot 50 and which wall 55 is located on the side of 
the pivot shaft 11. By virtue of this arrangement there is avoided that a 
build up of fibers will occur within the measuring groove or slot 50. The 
angle .alpha. amounts at most to 30.degree.. 
FIGS. 22 and 23 show an embodiment wherein there is provided a measuring 
groove or slot 50.1 analogous to the measuring groove or slot 50 of the 
prior discussed embodiment of FIGS. 20 and 21. This measuring groove or 
slot 50.1 is provided with a therewith operatively connected pressure line 
or conduit 51.1 as well as a pressure line or conduit 52.1. 
In contrast to the measuring means or arrangement of FIGS. 20 and 21, with 
the measuring means or arrangement the modified embodiment of FIGS. 22 and 
23 there is not only measured the pressure which, as described, results 
from the expulsion or displacement of the air out of the mass of fiber 
material, typically the batt or lap 15, rather there is additionally 
forced into the fiber material which is undergoing compression or 
compaction a constant quantity of compressed air delivered by a suitable 
compressed or pressure air source 56 by means of the measuring groove or 
slot 50.1. The throughpassage of this predeterminate amount of compressed 
or pressurized air through the fiber material, the batt or lap 15, occurs 
against the resistance of such fiber material, so that a pressure, 
corresponding to the resistance against the throughflow of air through the 
fiber material, can be transmitted from the pressure lines or conduits 
51.1 and 51.2 to a pressure converter or transducer 53.1 connected with 
the pressure line or conduit 51.2. 
Since the resistance to the flow of air varies with the density or 
thickness of the fiber material, in other words, that of the batt or lap 
15 in the region of the essentially invariable or unchanging size nipping 
zone or region, like the nipping zone or region 23.1 of FIG. 3 but not 
here specifically referenced, there also is altered the pressure in the 
lines or conduits 51.1 and 52.1. The pressure converter or transducer 53.1 
converts such pressure variations or fluctuations into the signal 16. 
As will be also evident from the illustration of FIG. 22, here also the 
measuring groove or slot 50.1 exhibits the angle .alpha. described 
previously with reference to the embodiment of FIGS. 20 and 21. 
FIGS. 24 and 25 show a variant embodiment of the measuring means or 
measuring expedient from that depicted in FIGS. 22 and 23. Here, the 
constant quantity of compressed pressurized air delivered by the 
compressed or pressurized air source 56.1 is blown by means of a blow or 
blow-in groove or slot 58 into the fiber material located in the region of 
the essentially invariable or unchanging size nipping zone or FIG. 2 but 
not here specifically referenced. This blown-in air migrates in such fiber 
material in a direction W which is opposite to the rotational direction U 
of the feed roll 9 until it can escape into the atmosphere by means of a 
venting groove or slot 59 and a venting line or conduit 57 connected 
therewith. 
A pressure converter or transducer 53.2 is connected with the line or 
conduit 52.2. This pressure converter or transducer 52.2 converts the 
pressure prevailing in the pressure line or conduit 52.2 into the signal 
16. There can be defined or determined a resistance region between the 
blow-in or blow groove or slot 58 and the venting groove or slot 59 by 
appropriate selection of the distance M between these components 58 and 
59, as indicated in FIG. 24. 
FIGS. 26 and 27 illustrate a variant embodiment of the fiber infeed means 
or device 2.2 from that depicted in FIG. 2. In the arrangement of FIGS. 26 
and 27 the fiber feed plate 10 is not only pivotable about the pivot shaft 
or axis 11, but such is additionally pivotable or displaceable about a 
further pivot shaft or axis 62 which is coaxially disposed with respect to 
the rotational axis of the feed roll 9. This pivotability has been 
schematically represented by the radius arrow line or radius S shown in 
FIG. 26. 
To render this pivotal motion possible, there is provided a holder bracket 
or holder 63 or equivalent structure, which possesses two legs or leg 
members 64 (only one of which is visible in the showing of FIG. 26) and in 
which leg members there is mounted the pivot shaft or pivot means 11. 
These legs or leg members 64 are connected with a continuous web or strut 
member 65 extending beneath the feed plate 10 (as viewed with reference to 
FIG. 26). This web or strut member 65 serves for accommodating the 
previously discussed stop or abutment 27. 
Additionally, the legs or leg members 64 each have a guide slot or recess 
66, the lower guide surface 67 of which, as viewed with reference to FIG. 
26, possesses a curvature having the aforementioned radius S. The upper 
guide surface 68 which is disposed opposite to the lower guide surface 67 
is arranged substantially parallel to the lower guide surface 67. 
These guide slots 66 each serve for the reception of two guide bolts or 
bolt members 69 which are fixedly arranged in a machine housing portion or 
part 70. The spacing of these two guide bolts or bolt members 69 is 
selected in relation to the length of the associated guide slot 66 such 
that the holder bracket or holder 63 is pivotable through a predeterminate 
pivot length about the pivot shaft or axis 62. 
In order to fixedly retain the holder bracket or holder 63 in a selected 
pivotal position, this holder bracket 63 is fixedly held by means of two 
screws or threaded bolts 71 or equivalent structure threaded into the 
machine housing part 70 and extending through the associated guide slot 
66. 
Additionally, the adjusting or adjustment screw 12 is arranged at an end 
portion 63.1 of the holder bracket or holder 63 and which is directed or 
extends towards the licker-in cylinder or roll 3. 
It should be clearly understood that also with this embodiment there can be 
used and combined all of the elements needed for generating the signals 16 
as have been described with reference to the various embodiments depicted 
in FIGS. 4 to 25 inclusive. Therefore it is unnecessary to repeat the use 
of these elements in conjunction with this variant embodiment of the 
invention. 
FIGS. 28 and 29 show a further embodiment of the fiber infeed means or 
device 2.3 from that shown in FIG. 3. In the embodiment of FIGS. 28 and 29 
there is provided a feed plate 72 having a nipping surface 72a and which 
is fixedly connected with the machine housing 25, whereas the feed roll 9 
is movable throughout a given region or range. 
The mobility of the feed roll 9 is attained by virtue of the fact that the 
free ends 73 of the here not particularly referenced rotational shaft or 
axis of the feed roll 9 and which protrude at both sides from the feed 
roll 9 (in FIG. 28 there is shown only one such side) are received in a 
respective associated bearing bushing or block 74 or equivalent structure. 
Each such bearing bushing 74 is displaceably guided between two stationary 
slide guides or guide members 75 and 76, respectively. The displacement 
range of the feed roll 9 is limited, on the one hand, by a stationary stop 
or abutment member 77 as well as by an adjustable or adjustment screw 78 
or equivalent structure. The adjustment screw 78 is received in a support 
or carrier 79 which, in turn, is secured to the machine housing 25. The 
stop or abutment 77 has the same function as the previously described stop 
or abutment 27. 
During operation, the mass of fiber material, for instance, the batt or lap 
15, is slidingly moved upon the feed plate 72 by the action of the feed 
roll 9 into the substantially wedge-shaped converging nipping zone or 
region 23 between the feed roll 9 and the feed plate 72. Consequently, the 
feed roll 9 is lifted out of its starting or initial position, in which 
the bearing bushings 74 each bear upon an associated stop or abutment 77, 
until attaining the operating position. In such operating position the 
bearing bushings 74 each bear against an associated adjusting or 
adjustment screw 78 constituting a related stop or abutment and form the 
essentially invariable or unchanging size nipping zone or region, like the 
nipping zone or region 23.1 of FIG. 3 but here again not particularly 
referenced. 
It should be understood that with the variant embodiment described with 
reference to FIGS. 28 and 29 there again can be used the elements or 
components discussed previously with respect to FIGS. 8 to 25 inclusive 
for generating the signal 16, so that no further explanations are believed 
to be here warranted. 
Turning attention now to the embodiment depicted in FIG. 30, there is 
illustrated therein a drafting arrangement 100, in which there is likewise 
used the previously described method. In this drafting arrangement 100 
there is employed a variant construction of fiber infeed means or device 
2.4 from that depicted and described with reference to FIG. 1. In this 
variant construction of fiber infeed means or device 2.4 there is 
utilized, instead of the feed plate 10 illustrated in the arrangement of 
FIG. 1, a counter roll or roller 101. The counter roll 101 with its 
nipping surface 101a together with the feed roll 9 forms the nipping zone 
or region, here generally indicated by reference numeral 120. 
In contrast to the feed roll 9 in this case the counter roll 101 is not a 
driven roll, that is to say, it is a freely rotatable roll and is dragged 
by the entraining action of the mass of fiber material, for instance the 
sliver or band 15.1 or the like, which is located between the counter roll 
101 and the feed roll 9 arranged in confronting and coacting relationship. 
This counter roll 101 is mounted to be rotatable and also is pivotably 
mounted at the pivot lever or lever member 102. 
The further elements or components shown in the arrangement of FIG. 30 
generally correspond to the elements or components described previously in 
conjunction with the embodiment of FIG. 1. Hence, as a matter of 
convenience in illustration in this variant embodiment of FIG. 30 there 
have been generally used the same reference characters to denote the same 
or analogous components. It will be thus apparent that, for instance, the 
pivotal lever or lever member 102 is pivotably mounted by means of the 
pivot shaft 11 and the bearing housing 26. 
In order to generate the signals 16 there is used, for instance, as the 
measuring expedient or structure the force measuring cell or unit 41 
previously described in conjunction with the embodiment of FIGS. 8 and 9. 
Hence in this regard reference may again be had to the prior described 
arrangement of FIGS. 8 and 9. 
The roll or roller pair designated by reference characters 103 and 104 are 
well known types of rollers used in conventional drafting arrangements and 
thus need not be here further described. At this point it is only 
mentioned in conjunction with the function of the fiber infeed means or 
device 2.4 that both of the lower rollers of the roll or roller pair 103 
and 104, as viewed in connection with the showing of FIG. 30, are driven 
at a predetermined or fixed rotational speed which governs the draft in 
the drafting arrangement 100. The upper rollers of this roller or roller 
pair 103 and 104 are likewise dragged by the action of the mass of fiber 
material 15.1 which drags the roll or roller 101. 
The drafting relationship of the spinning machine depicted in FIG. 30 is 
governed by the circumferential velocity of the feed roll 9, dictated by 
the rotational speed of the shaft 21 of the drive motor, namely the 
gearing or transmission motor 13, and by the circumferential velocity of 
the lower roll or roller 104, dictated by the rotational speed thereof 
which generates the rotational speed signal 19.1. This signal 19.1 has the 
same function as the signal 19 of the embodiment of FIG. 1. Here also 
elements or components which have the same function as those previously 
considered have therefore been generally conveniently identified by the 
same reference characters. 
Furthermore, the device or apparatus 110 for determining or detecting the 
density of the delivered fiber sliver 8 or the like, and described 
previously with reference to FIG. 1 and known, for instance, from the 
aforementioned European Patent No. 0,078,393 and the cognate U.S. Pat. No. 
4,539,729, is provided directly after the fiber compaction funnel or 
condenser 112. 
In this device or apparatus 110, there is provided a pair of rolls or 
rollers 113 and 114 which can be pressed or urged towards one another, and 
the peripheral portions of which can interengage with one another such 
that there is formed a laterally limited clamping zone which guides the 
fiber sliver 8. The one roll or roller 113 is stationary and the other 
roll or roller 114 is movably arranged in order to carry out a movement 
corresponding to the fluctuations or variations of the density or weight 
or thickness of the delivered fiber sliver 8 or the like. These movements, 
in the field of application of such known device or apparatus 110, are 
scanned by a conventional proximity sensor or switch (not shown) or 
equivalent structure and there are then produced the signals, generally 
indicated by reference character 116, on the line or conductor 111 which 
correspond to the density or weight fluctuations or the like. 
Instead of using a proximity switch, as a modification of the invention, 
and as depicted with broken lines, the movement of the roll 114 can be 
limited in the manner analogous to the counter roll 101 by an abutment or 
adjustment screw 12.1 provided or coacting with a force or pressure 
measuring cell 41. In this case the roll 114 is rotatably mounted at a 
pivot lever 115 which in its function corresponds to the pivot lever 102, 
and the pivot lever 115 is pivotably mounted by means of a pivot shaft or 
axis 11.1 in a bearing housing 26.1 fixedly arranged at the machine 
housing 25. 
During operation the fiber sliver 8 opens the rolls 113 and 114 by a 
predeterminate amount, that is to say until the pivot lever or lever 
member 115 abuts against the abutment or adjustment screw 12.1. The 
different forces which thus arise in the stationary or invariable size 
nipping zone or region between the rolls or rollers 113 and 114, 
corresponding to the different density or weight of the fiber sliver 8, 
are detected by the force measuring cell 41 and delivered as the 
aforementioned signals 116 to the control or control device 17. 
Here also elements or components having the same function as previously 
described have been conveniently generally designated by the same 
reference characters. 
There are numerous advantages which arise by virtue of the teachings of the 
present invention. One advantage which is obtained by fixing the 
throughpass region for the fiber mass, typically the nipping zone or 
region, in other words providing a stationary nipping zone or region, 
i.e., a nipping zone or region which does not change in size during 
operation of the equipment, in order to measure density or thickness 
variations of the intermediately situated mass of fiber material, for 
instance the batt or lap or sliver or band, in contrast to the heretofore 
known measuring techniques and equipment of the prior art for 
accomplishing such measuring techniques and specifically relying upon 
distinct and visible and measurable alterations or variations in the size 
of the nipping zone or region resulting from variations in the density or 
thickness of the throughpassing fiber material, is that with the teachings 
of the present invention the measuring signals have an appropriately large 
amplitude owing to the intensive force variations which can be reliably, 
sensitively and quite accurately detected. A further advantage resides in 
the fact that when working with the force measuring technique or method 
and equipment of the present development the undesirable hysteresis 
effects which arise when using a displacement measuring technique in a 
changing or varying size nipping zone or region, as proposed in prior art 
constructions, are eliminated or at least appreciably suppressed, thus 
providing a more accurate or true measurement result. 
A further advantage obtainable with the teachings of the present invention 
is that when using the inventive force measuring technique there can be 
ascertained density or thickness variations of the infed mass of fiber 
material at a discrete location or region of a fiber feed element or 
equivalent or specific detection element at which the forces to be 
detected are exerted, such as the feed plate which is held stationary or 
immobile against the coacting stop or abutment during operation, resulting 
in a much more sensitive and precise detection of undesirable alterations 
or variations in the density or thickness of the fiber material. This 
detection location is advantageously near to but upstream of the fiber 
transfer nose of the feed plate considered with respect to the travel 
direction of the mass of fiber material. In other words, the determination 
of thickness variations of the fiber material, such as the batt or lap, is 
accomplished near to the narrowest location of the nipping zone or region 
between, for instance, the feed plate and the feed roll, that is, 
essentially near to that location at which the fiber material is received 
by the licker-in roll. Consequently, there is obtained an extremely short 
path between the measuring location and the fiber transfer location, or, 
stated in another way, the point in time at which there is accomplished 
the measurement is quite close to the point in time when there is 
undertaken the required rotational speed correction of the feed roll. 
Finally, it is mentioned that various modifications can be undertaken and 
will suggest themselves to those skilled in the art without departing from 
the underlying principles and teachings of the present invention. For 
instance, it is conceivable to use instead of a continuous feed plate a 
plurality of smaller feed plates or pedals arranged next to one another, 
each of which is then appropriately structured to sense the force of the 
mass of fiber material acting thereupon and to generate a corresponding 
signal which is appropriately processed to produce the signals infed into 
the control which are then ultimately utilized for producing the 
controlled speed variations of the driven feed roll. Also the stops or 
abutments can be arranged at any desired locations such as at opposite 
ends or end regions of the feed plate which is to be immobilized. 
While there are shown and described present preferred embodiments of the 
invention, it is to be distinctly understood that the invention is not 
limited thereto, but may be otherwise variously embodied and practiced 
within the scope of the following claims. Accordingly,