Method and apparatus for bale weight control

The total weight of fibrous material delivered to a packaging device, such as staple textile fiber delivered to a baling press, is controlled so as to facilitate achieving more uniform package weight in accordance with a method and through the use of an apparatus in which material is successively accumulated into batches, each of which is a fractional portion of a desired package weight. Batches are accumulated and released as the actual weight of each delivered batch is determined and registered and the registered actual weights of the successive batches are totaled. The weight of at least certain batches in the succession is then adjusted in such a manner as to closely control the total weight. A weigh container having an inlet and an outlet is interposed between and operatively communicates with a source of supply of fibrous material, such as a tow cutter, and a packaging device, such as a baling press. A load cell is provided which signals the weight of material supported by the weigh container.

Certain fibrous materials which are sold primarily by weight measure are 
processed or manufactured in substantially continuous processes. One 
example of such a material is staple textile fiber, which is commonly sold 
by fiber processors or producers to textile manufacturers on a weight 
basis. Staple textile fiber includes natural fibrous materials such as 
cotton, wool and flax as well as man-made or synthetic fibrous materials 
such as nylon, cellulose acetate, rayon, acrylics, polyester and 
polypropylene. Particularly with regard to man-made fibrous materials, the 
manufacture of the fiber is a substantially continuous process in which a 
tow is spun. Substantial effort has been denoted to the development of 
methods and apparatus for producing tow and cutting that tow into staple 
textile fiber in a substantially continuous manner. 
As is true with other fluent or flowing materials sold by weight measure, 
it is desirable if not necessary for sellers and buyers of staple textile 
fiber to know substantially the exact weight measure of each package or 
bale and the total weight of material transferred in any particular 
transaction. Heretofore, particularly with staple textile fiber, the 
practice has been to package material and subsequently weigh the package 
of material to determine the actual weight of the package or bale. The 
package or bale is then marked with the actual weight and, if the bale 
weight is outside predetermined limits for weight variation tolerance, the 
bale is taken apart and reprocessed into other packages or bales. 
As can be appreciated, substantial variation in bale or package weight from 
bale to bale introduces significant difficulty of inventory control in 
filling orders which may be expressed in terms of specific desired total 
weights. Further, and particularly with staple textile fiber, bales of 
significantly varying weights present difficulty for textile manufacturers 
seeking to blend fibers in a particularly desired weight ratio or 
percentage. In the specific instance of staple textile fiber, it has 
become common to encounter variations in bale weight on the order of sixty 
to one hundred pounds above or below a desired package weight, in 
circumstances where the desired package weight is in a range of from about 
four hundred fifty pounds to about eight hundred pounds. The percentage 
fluctuation represented can be appreciated as contributing to the 
difficulties encountered prior to development of the present invention. 
With the aforementioned difficulties and deficiencies in mind, it is an 
object of this invention to facilitate achieving more uniform package or 
bale weights in the processing and handling of fibrous materials such as 
staple textile fiber. In realizing this object of the present invention, a 
continuing flow of fibrous material is divided into a succession of 
batches, each of which is a fractional portion of a desired package or 
bale weight. Batches are accumulated and released as required to deliver a 
total weight of material substantially equal to a desired package weight, 
while the actual delivered weights of successive batches are determined, 
registered and totaled. The weight of at least certain batches in the 
succession is adjusted as required for closely controlling the total 
weight of material delivered. 
Another object of this invention is to package fibrous materials in 
packages of consistently substantially equal weight. In realizing this 
object of the present invention, successive packages formed are each 
formed to have the same weight, within close tolerances. Thus, transfer of 
a desired total weight of fiber in any transaction is simplified in that 
packages or bales of standardized weight may be selected at random rather 
than requiring careful selection of packages totaling the desired weight. 
A further object of this invention is to take into account, in achieving a 
desired total package weight, quantities of staple textile fiber which may 
for various reasons and varying lengths of time be delayed in movement to 
a baling press or packaging means. More particularly, in the event that a 
given quantity of fiber for some reason is inadvertently trapped or hung 
up in the flow path of material being batched and weighed, the arrangement 
of the present invention determines and takes into consideration the 
weight of such fiber. In realizing this object of the present invention, 
control circuitry responds to load cell signals indicative of the weight 
of a weigh container and material supported thereby, with the response of 
the controller being such as to add or adjust subsequent weights as 
necessary to compensate for "in-flight" fiber and fiber inadvertently 
retained, all as described more fully hereinafter. 
Yet a further object of this invention is to facilitate blending of fibrous 
materials delivered into a further manufacturing process. More 
particularly, the divison of a continuing flow of fibrous material into a 
succession of batches and adjustment of weight of such batches is 
contemplated as accomplishing substantially continuous, on-going process 
control capable of delivering continuing flows of each of a plurality of 
different fibrous materials, thereby accomplishing blending of the 
materials in predetermined ratios.

While the present invention will be described hereinafter with more 
particular reference to the accompanying drawings, it is to be understood 
at the outset that the following more detailed description of this 
invention and the accompanying drawings are directed to the persons 
skilled in the applicable arts. It is anticipated that such persons 
skilled in such arts will be able, from the illustration and description 
of a presently preferred mode and arrangement of the present invention, to 
modify methods and apparatus while embodying the substance of the present 
invention. Accordingly, the following description is to be read as a broad 
teaching of this invention, and not as being restrictive on the scope of 
protection to which this invention of properly entitled. 
The present invention contemplates that fibrous material to be packaged or 
delivered to a subsequent manufacturing process such as a blending process 
is supplied in a continuing flow. More particularly, such material in the 
form of staple textile fiber results from the delivery of a filamentary 
textile tow from any appropriate and desired process and apparatus. The 
manufacture of such filamentary textile tow forms no part of the present 
invention and is well known to persons skilled in the applicable fiber 
producing arts. As is known to such persons, filamentary textile tow is 
commonly delivered to cutter means for cutting the filamentary textile tow 
into staple textile fiber. Again, the specific structure and operation of 
a tow cutter is known to persons skilled in the applicable arts and 
accordingly will not be here described in great detail. Interested readers 
may refer to relevant prior patents directed specifically to inventions 
relating to tow manufacture and cutting. Staple fiber cut by any such tow 
cutter is, in the apparatus of FIG. 1, delivered to a holding chute 10 by 
any suitable means. 
Heretofore, staple textile fiber produced on a substantially continuous 
basis by cutting filamentary textile tow has been delivered to a packaging 
means in the form of a baler means or baling press. One form of baling 
press has been generally indicated at 11 in FIG. 1, but will not be here 
described in detail as detailed disclosures of baling presses are 
available to interested readers from prior patents issued in relevant 
arts. Similarly, blending apparatus suitable for receiving continuing 
flows of each of a plurality of different fibrous materials are known to 
skilled persons. 
In accordance with the present invention, fibrous material in the form of 
staple textile fiber passes from the tow cutter to the baler 11 or to a 
blending apparatus (not shown) in a succession of batches accumulated in a 
weigh container generally indicated at 12. The weigh container 12 has an 
inlet 14 and an outlet 15, each with respective means for opening and 
closing to respectively control admission of material into the weigh 
container from the tow cutter 10 and delivery of material from the tow 
cutter to the baler 11. The weigh container 12 is supported by an 
appropriate arrangement of balance beams 16, including a load cell 18 
which responds to imposition of weight or force by the weigh container and 
its contents by signaling the load or weight imposed. Preferably, and as 
described more fully hereinafter, the load cell 18 produces an analog 
electrical signal indicative of force loading or weight to which the load 
cell 18 is subjected. 
In accordance with the present invention, a programmed control circuit 
means preferably at least in part in the form of an electronic 
microprocessor indicated at 20 is operatively connected with the load cell 
18 for receiving signals therefrom and with the inlet and outlet 14, 15 of 
the weigh container 12 for controlling the opening and closing thereof. 
The programmed control means additionally is connected with certain 
operator set input devices and certain digital display devices, as 
described more fully hereinafter. As will be described hereinafter, the 
programmed control means functions for determining the actual weight of a 
batch of fiber delivered to the baler, for registering the actual weight 
of the delivered batch, for opening and closing the inlet and outlet in 
sequence as required to accumulate and deliver successive batches having a 
total weight of fiber substantially equal to a desired bale weight, for 
determining and registering the actual weights of the successive batches 
while totaling the registered actual weights, and for adjusting the weight 
of at least certain batches in the succession for closely controlling the 
total weight of material delivered. 
The present invention contemplates that the programmed control means may 
take a number of specific forms and may be selected from among available 
devices or by assembly of a plurality of such devices by persons skilled 
in the applicable arts, once an understanding of the present invention has 
been obtained by reading this description thereof. Accordingly, and due to 
the rapid rate of change of commercial products offered as programmed or 
programmable control means and as components thereof, the following 
description will not specifically indicate precise commercial devices to 
be employed. Instead, the functions sought will be described in a manner 
sufficient to inform the persons skilled in the appropriate art. 
As illustrated in FIG. 2, separate memory areas are provided for certain 
recording functions to be described more fully hereinafter. As will be 
appreciated by knowledgeable persons, such memory areas are not usually 
readily definable in terms of specific hardware or components but are 
commonly defined by programming or "software". As a result, what has been 
shown and will be described as separate memory means can be and usually 
are accommodated within varying numbers and types of chips, magnetic 
devices and the like. The present description will not, for the reasons 
given above, attempt to fully review the range of such choices available 
to the skilled computer technologist. Similar input-output devices, 
sensors and the like will not be fully reviewed. 
By way of example, the inlet 14 and outlet 15 may be operated 
pneumatically, hydraulically, electrically or by other appropriate means. 
Accordingly, it is contemplated that the control means either be 
compatible with such varying modes of actuation or be interfaced to the 
selected mode by an appropriate input or output device. As will be 
appreciated, the same circumstances apply with regard to the load cell 
means 18, as it is known that load cells signaling in various appropriate 
manners are available. 
As indicated above, it is preferred that the programmed control means at 
least in part take the form of an electronic microprocessor 20. In such a 
form, appropriate input devices in the form of thumbwheel switches or the 
like are provided as a desired bale weight input device 21, a desired 
batch weight input device 22, and an adjusted weight input device 23. The 
input devices are mounted on or in a control cabinet, for access by an 
operator or supervisor as management may decide. Information manually set 
up or indicated on the input devices 20, 21, 23 is available to and may be 
employed by the microprocessor 20. The microprocessor operatively 
communicates with memory means either provided within the microprocessor 
or provided by selected auxiliary devices. In accordance with this 
invention, the memory means include a predetermined weight memory means 
24, a full container memory means 25, and empty container memory means 26, 
and an "in-flight" memory means 27. Interaction among the various inputs, 
outputs and memory means is controlled by a central processing unit or 
processing means incorporated within the microprocessor 20 and possibly 
forming substantially the only component thereof. 
The process of the present invention includes supplying a continuing flow 
of fibrous material, preferably by cutting filamentary textile tow into 
staple textile fiber through operation of the cutter 10 referred to 
hereinabove. Under the control of the microprocessor 20, which may be set 
in motion by means of a manual start signal or by a program step as 
described hereinafter, the inlet 14 to the weigh container 12 is opened 
and fiber is admitted thereinto while the load cell 18 signals the weight 
of the container and fiber supported thereby. Signals originating from the 
load cell means 18 are received as an input by the microprocessor, which 
has carried into the predetermined weight memory means 24 the desired 
batch weight indicated by the setting of the appropriate input device 22, 
when the preparation of an idividual bale has just been initiated. Upon 
the signaled weight increasing to a predetermined weight corresponding to 
the weight recorded in the predetermined weight memory means 24, the inlet 
14 is closed and the admission of fiber to the container 12 is stopped. 
As will be appreciated, the desired batch weight and the weight indicated 
by the predetermined weight memory 24 may be substantially less than the 
quantity of fiber or material required to occupy the entirety of the 
weight container means 12. Accordingly, upon closure of the inlet 14, some 
fiber or material may be "in-flight" within the weigh container 12 and not 
be supported thereby so as to contribute to the total weight then 
instantaneously being signaled by the load cell means 18. Accordingly, a 
predetermined interval of time is allowed by the program of the 
microprocessor 20 for such "in-flight" material to settle within and be 
supported by the weigh container means 12. Thereafter, the microprocessor 
20 records in the full container memory means 25 a signal originated from 
the load cell means 18 and indicative of the weight of the batch of fiber 
then supported within the weigh container means 12. The outlet 15 is then 
opened to release fiber from the weigh container means 12 to the baler 11. 
The batch of fiber thus released has a weight which is a fractional portion 
of a desired bale weight, as manually indicated by the setting of the 
appropriate input device 21. Thus, it is necessary that a plurality of 
such batches be accumulated and released, in succession, in order to 
supply to the baler 11 that quantity of fiber or material which is to be 
packaged together. However, the successive batches have weights which are 
for a number of reasons subject to variance. In order to assure that the 
final total weight of material delivered for packaging closely approaches 
the desired bale weight, provision is made for determining the actual 
weight of each delivered batch. More particularly, after closure of the 
outlet 15 and prior to opening of the inlet 14, the microprocessor 20 
again notes the weight of any fiber retained within the weigh container 
means 12 as signaled by the load cell means 18 and records a signal 
indicative of such weight in the empty container memory means 26. The 
availability of a recorded signal indicative of full container weight in 
the full container memory means 25 and a recorded signal indicative of 
empty container weight in the empty container memory means 26 permits 
comparison of the recorded signals so as to compute quite accurately the 
actual weight of the delivered batch of fiber. 
As can be appreciated, the steps of opening and closing the inlet and 
outlet 14, 15 are repeated as required to deliver successive batches 
having a total weight substantially equal to the desired package weight, 
while the actual weights of the successive batches are determined and 
registered. As this occurs, the registered actual weights of the 
successive batches are totaled and preferably are displayed at some form 
of direct digital display device visible to an operator of the packaging 
system or the baler means 11. Repetition of the steps of delivering 
successive batches will, in accordance with the present invention, result 
in formation of successive packages of substantially equal weight. Thus, a 
succession of packages formed in accordance with this invention may be 
readily substituted one for another without unacceptably large fluctuation 
in the total fiber weight transferred. Similarly, repetition of the steps 
over more or less extended intervals of time result in delivery of fibrous 
material at a known rate of flow which facilitates other substantially 
continuous processes such as blending of different fibers. 
In accordance with important characterizing features of this invention, the 
weight of at least certain batches in the succession is adjusted by the 
microprocessor 20 in order to more closely control the total weight of 
fiber delivered to the packaging or baler means 11 and so as to facilitate 
achieving more uniform bale weight. The present invention contemplates 
that the programming of programmed control circuitry means such as the 
microprocessor 20 may be accomplished by persons skilled in the applicable 
arts once an understanding of the present invention has been gained from 
the descripion provided herein. As one example of a set of instructions 
for a programmed control means, FIG. 4 of the accompanying drawings sets 
out a programming flow chart in which the symbol B1 indicates a batch 
weight as may be manually set on the desired batch weight input device 22 
and the symbol B2 represents a desired bale weight as may be manually set 
at the desired bale weight input device 21. The symbol N1 represents the 
total number of batches required to deliver a total weight of fiber 
substantially equal to the desired bale weight, while the symbol NA 
represents the number of batches which have been previously delivered 
through the weigh container means in the process of delivering a desired 
bale weight of fiber. The symbol WT represents total weight actually 
delivered in a succession of batches, while .DELTA. WTOT represents a 
total of "in-flight" weights computed during processing of a succession of 
batches. The symbol W1 is employed to represent the predetermined weight 
of material or fiber to be admitted to the weigh container means 12, as 
recorded in the predetermined weight memory means 24 and as adjusted 
during the progress of the program. The symbol W2 represents the weight of 
material in the weight container means 12 immediately prior to opening of 
the outlet 15, as may for example be recorded in the full container memory 
means 25. The symbol W3 represents the weight of any material or fiber 
which may be retained in the weight container means 12 after discharge of 
a batch therefrom, as may be recorded in the empty container memory means 
26. The symbol .DELTA. W represents the weight of "in-flight" fiber which 
is passing in the weigh container 12 immediately after closure of the 
inlet 14 and is subsequently supported by the weigh container means 12 
prior to opening of the outlet 15, while the symbol .DELTA. WA indicates a 
computed average of .DELTA. W weights for successive batches. 
As will be apparent to knowledgeable persons from FIG. 3 of the 
accompanying drawings and the above elucidation of the symbols there 
employed, the signal recorded in the predetermined weight memory means 24 
may be adjusted during processing of each batch in the succession of 
batches, so that the accumulating total weight of fiber is continually 
adjusted to approximate an ideal staircase or stepwise increase to the 
desired total bale weight. An alternative program achieving substantially 
the same results may defer adjustment of the predetermined weight until 
the last few or one batch in a succession of batches. A program flow 
diagram for such an arrangement is indicated in FIG. 4, where symbols 
consistent with those described with reference to FIG. 3 have been used, 
with one exception. The program diagramed in FIG. 4 provides for the 
computation of a weight remaining to complete a desired bale weight, 
symbolized as WREM, which is compared with desired batch weight W1 in 
determining the programmed adjustment to be made to W1. 
As a further alternative, this invention contemplates that the desired 
batch weight W1 for a known, predetermined number of final batches in a 
succession may be taken from a manually set input device such as the 
adjusted weight input device 23. In accordance with such a procedure, 
program determination that the number of batches delivered was within two 
(or some other suitable integer) of the number required would be followed 
by setting W1 to be the manually determined weight rather than a computed 
weight. 
It has been determined that a succession of bales produced in accordance 
with the methods of this invention may be quite closely controlled as to 
the weight of each bale in the succession, thereby permitting any one bale 
in the succession to be substituted for any other one bale in warehousing 
or delivery of fiber. More specifically, a succession of bales having 
weights in the range of from about 450 pounds to about 800 pounds may be 
formed while holding the variation in bale weight of any given bale in the 
series to the range of from about 1 pound to about 8 pounds above or below 
the desired bale weight. Thus, the percentage fluctuation experienced will 
be in the range of no more than three percent of bale weight and 
preferably about one percent or less. 
In the drawings and specification, there has been set forth a preferred 
embodiment of the invention, and although specific terms are employed, 
they are used in a generic and descriptive sense only and not for purposes 
of limitation.