DE2344302A1 - PROCEDURE AND DEVICE FOR DETERMINING THE MAXIMUM SAFETY VALUE OF THE DECLARATION WEIGHT OF OBJECTS - Google Patents

Description

PATENT LAWYERS

DR. ING. VAN DER WERTH DR. FRANZ LEDERER

2t HAMBURG 9O 8 MUNICH SUN

WILSTOiPH ST «. S3 · TEL. «Mill 770861 LUCUE-CRAHN-STR. 33 · TEL. CQe !!> - t729 * 7

August 28, 1973

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W 163

Applicant: Unilever NV, Burgemeester s ^f Jacobplein 1, Rotterdam, Netherlands

"Method and device for determining the maximum safety value of the declaration weight

of objects

The invention relates to weight control for a number of objects with a nominal declaration weight.

The expression "nominal declaration weight" is used in the context of this Description used to define the weight declared to the customer, usually that indicated on the packaging Weight is. It is known that in the machine filling of packs to a predetermined weight, i.e. a target or Target weight, a range around this target or target weight to be observed, since individual packs are lighter and individual packs are more severe, and it can also be observed that this deviation usually follows a normal distribution curve. Good business conduct and, in some cases, legal requirements require that a large proportion of the packs be at least that Weight indicated on the packaging and generally slightly more for safety reasons. For this reason, means of the filling machines filled to a target or target weight, the

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is greater than the nominal declaration weight. In some cases is the minimum difference between the target or target weight and the nominal declared weight effectively through laws or regulations set as the standard deviation of the normal distribution curve.

In practice, during the operation of a machine, result in one specified target or target weight, fluctuations in external parameters, errors, deviations of the products with regard to their components etc. to a deviation in the spread of the normal distribution curve. To eliminate this source of error and always be on the safe side Side work, the target or target weight is usually set slightly higher than necessary. Thus, more product is in the Packs filled as absolutely necessary and this extra quantity is given "free of charge" to the customer. Thus, higher production costs result from this "free" charge.

Ideally, the target or target weight would be set so that between the target weight, the target weight and the nominal weight stated on the package Declaration weight is always the optimal minimum difference. However, this requires the calculation of the standard deviation, and in practice it tends to be difficult to do so quickly and easily enough for deployment to use.

The invention relates to a method suitable for these purposes and a device for carrying out the same.

To this end, the invention provides a method for determining the maximum safety value of the declared weight of a number of objects with the nominal declared weight, which is carried out by the following steps:

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a) formation of a sample group from a predetermined number of objects in the row,

b) Subdivision of the objects of the group into subgroups of the same kind Number,

c) Determination of the heaviest item and the lightest item in each subgroup,

d) Arrangement of all lightest objects at a first weighing station a scale,

e) Arrangement of all heaviest objects at a second weighing station the scales,

f) Carrying out a weighing with the aid of the scales to determine the difference between the product of the total weight, which represents the maximum reference value of the declaration weight

ζ + 0 5 of the lightest objects and ( '· -) and the product of the

ζ - 0 5 total weight of the heaviest objects and (-),

where η is the number of objects in the sample group in the Row and ζ one of the tolerated difference between the declaration weight and the average weight of the objects is the constant dependent on the series.

Usually the constant ζ lies between 1.5 and 3, and it is proportional to the number of standard deviations tolerated between the average weight and the declared weight; this will continue explained in more detail below. It is set by the operator depending on the legislation or requirements relating to the weights of the weighing inspectors or inspections and the degree of safety required during weighing.

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By finding the difference between the two stated math products becomes the average sample area reached and from this the standard deviation and thus the maximum Safety of the declaration weight. The mathematical conversion of the average sample area to the standard deviation is Part of the standard theory of statistics (see "Facts from Figures", M.J. Morone, Penguin Books Ltd., page 155).

It should be noted that the expression of the maximum safe value of the declared weight used is often referred to as the "hazard point" or defined or limited percentage of the normal distribution curve and does not represent the same as that on the
Nominal declared weight specified in the package. It is the maximum value at which the nominal declaration weight can be secured without violating regulations or practical requirements.

For example, in the United Kingdom of Great Britain, for certain products, this is how the legislation dealing with weights in practice becomes
interprets that 97.5 % of a production must be above the declared weight (the relevant legal requirements differ from country to country). This means that the average or target or target weight must be 1.96 standard deviations above the declared weight. The two constants must be selected with a view to fulfilling this requirement and after the procedure has been carried out
To achieve the maximum safety value of the declared weight, the answer received is the same as the one on the package
the specified nominal declaration weight.

If the nominal declaration weight stated on the package is greater than that achieved by way of the method according to the invention

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Value of the declaration weight, it means that the packs are underweight and should not be sold.

However, the invention has further practical value, because it enables the target or target weight of the filling machine adjusted for optimal performance. This means that if the determined in the context of the method according to the invention the maximum safety value of the declaration weight is greater than the nominal declaration weight stated on the package, the filling machine fills more material than necessary into the pack and should be adjusted accordingly. In practice it is permissible change the target or nominal weight by almost the size of this difference, since the entire normal distribution curve is uniform is shifted and then the target or target weight is exactly above the minimum legally permitted difference from the nominal Declaration weight.

It should be noted that it is particularly useful to use a mathematical Product of a weight and a constant with another such mathematical product on a beam scale to be compared, since these products can be represented as moments around a pivot or support point. Thus, the weighing can be on a beam balance with a pivot point and three weighing stations at different, predetermined distances from the pivot point the first and second stations being arranged to act in opposition to each other, and the third Station forms a position for measuring the maximum safety value of the declaration weight.

Thus, the invention also provides a weighing device for determining the maximum safety value of the declaration weight for a Series of items with a nominal declaration weight,

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1M44302

the one beam balance with three weighing stations at different distances from a fulcrum, these distances from one another

in the ratio 1: (): f ), at which point

n ' ^K η'

ratio η is the number of objects in a sample group in the Series and ζ is a constant derived from the tolerated difference between the declared weight and the average weight of the Items depends on the series.

While it is in principle possible to use subgroups, which each consist of the same number, but otherwise any number of objects, it is easiest and most useful to have subgroups to use, which consist of only two objects.

As is well known, the accuracy and distinctiveness of the. the certain maximum safety value of the declaration weight "Larger, the larger the sample. If the subgroups consist of two items, at least four subgroups should be used to achieve of a significant result. The use of five subgroups is reasonable and reasonable Way significant, while five subgroups are still easy to handle. The value n, the number of objects in a sample group, ranging from eight to twelve, and preferably be at ten.

When the subgroups. Are twos, the spacing should be like this be selected so that the following relationship is fulfilled in the equilibrium position of the balance beam: maximum safety declaration weight = L (0, 5 + 0.8862 K) + S (0, 5 - 0, 8862 K), where K is a factor that determines the permitted number by the ge i et ζ ge or Practice of tolerated underweight items in units of the permitted standard deviations between the average weight

409812/0914 owginally inspected

and the declared weight and L and S are the average weights of the lighter and heavier items. The constants ( ^l -) and ( ^ί —-) are based on this relationship.

The derivation of the formula is further detailed in context explained with the example described.

An advantageous and expedient device can be a beam balance, as indicated and also a second scale, preferably one Have a beam balance with two equal pan arms for determining the lighter and heavier objects.

The following is an embodiment according to the invention Described with reference to the drawings; in this shows:

.Fig. 1 shows a perspective view of a balance, FIG. 2 shows a diagram for explaining the principle of this balance, and FIG

Fig. 3 is a graph showing the normal distribution of weight variation.

Figures 1 and 2 show a simple device for implementation the invention. First, however, reference is made to Figure 3, which graphically illustrates what the invention is made of Has.

The solid curve is a curve of a usual normal distribution the weight G over the number η of objects for a given weight. The top of this curve represents the average weight and in practice a filling machine will fill to a target or target weight ZG according to this average weight carry out. Then it will depend on the legal

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INSPECTED

According to requirements or accepted practice, there will be a point on this curve which indicates the maximum value of the weight that is on can be specified on the package (this weight can be such that 97.5% of the items are above the declared weight, as this is required in individual countries, or depending on the requirements in other countries, more or less many items above the declaration weight; however, the principle is each the same thing). This weight is entered on the curve as MWDG (maximum value of the declaration weight).

In practice, a special weight, here called the nominal declaration weight NDG, is usually on stated on the pack, and the purpose is to sell a product that comes as close to that weight as it is technically and is possible due to legal regulations.

In the example shown, the MWDG is above the NDG, so that the legal requirements or the requirements of practice are fulfilled, but the objects have a greater weight than necessary and the mode of operation is not economical Optimal takes place. To achieve the intended purpose, the target or target weight of the filling machine is therefore down to one new target or target weight ZGl shifted by an amount that shifts the MWDG down to a point where it is actually with NDG coincides and the entire normal distribution curve is shifted to the dashed line position.

The present invention uses a particular form of weighing scale, which automatically calculates or determines the position of MWDG for this group for a given group of objects and thus enables that the target or target weight or the nominal declaration

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weight is adjusted accordingly.

The weighing device has five weighing pans Wl, W2, L, S and DG. The mutual connection of these scales is shown in Figure 2, "where the points D each denote a fixed pivot point.

The weighing pans Wl and W2 stand over a simple beam balance only two beam arms of equal length on both sides of a pivot point Dl in connection and their task is to determine the heavier and at the same time the lighter object in each pair.

The weighing pans S, L and DG are connected to one another via a more complex connection. The weighing pan S is used to hold all heavy objects of a sample and is at a distance A from one Pivot point D2 arranged. The weighing pan L for the lighter items is at a distance B from the pivot point D2 to the other Side arranged. At a further distance C becomes an upward one Force from the weighing pan DG (for the declaration weight) brought into action on a Sehwenkverbindungen SV. This up Directed force is transmitted via a beam balance with two beam arms of equal length on both sides of a pivot point D3, however, in another embodiment, the weighing pan DG is arranged at the same distance C to the other side of the pivot point D2 and connected directly without the additional beam balance with beam arms of the same length.

The distances A, B and C depend on the permitted Tolerance and the size of the sample chosen. Appropriately and advantageously the sample group can consist of ten objects, the weighing procedure being carried out as follows: From the current Ten objects are removed from production, the first two of which are placed on the weighing pans W1 and W2, around the heavier one

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.. 10 -

and at the same time to determine the lighter object, after which the the heavier object is placed on the weighing pan S and the lighter object is placed on the weighing pan L; the latter two processes are repeated with the remaining objects in any pairs, after which five objects are placed on the scales S and L rest. After that, weights are finally placed on the weighing pan DG until the complex scale is in the Rest position is. The weight on the weighing pan DG then indicates the maximum safety declaration weight.

In practice, an empty package is used together with weights to achieve the nominal declared weight (i.e. the weight on the Pack specified weight) is first placed on the weighing pan DG, and then a weight correction is made to achieve of the equilibrium recorded or noted. This correction is the amount by which the target or target weight is increased for optimal operation should be set or corrected.

The weight compensation is based on the following relationship: A. 3ES = B-SL-C DG.

Where: A, B and C are constants,

S the sum of the heavy objects, L the sum of the light objects and .DG the maximum safety declaration weight.

This relationship applies as a result of the following relationship:

Declared weight = target or target weight (or average weight) - K standard deviations, where K is the factor defining the hazard level.

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The standard deviation can be derived from the average sample amount can be determined using the following standard formula:

S = i - / T (Sr - 1_) I - A _o ,

■ where A is a constant that depends on the number of objects from which the set is calculated, and m is the number of sets and S and L the heavier and lighter objects in each Amount are. The target or ball weight is from the relationship - ^ X where η is the number of packages in the sample and X is the weight of each item in the sample. "If a number of Samples are taken and each set simply consists of two objects, A = 0.8862. In this case can through Substitution and conversion the following relationship can be derived directly:

Declaration weight = L (0.5 + 0, 8862 K) + S (0, 5-0, 8862 K), this is the same as the relationship

A "Zs = B -JL - C · DG,

, _. λ 0.5-0.8862 K. ,. . , "■ ■ where A = - ', η is the number of heavy objects and K is the hazard factor, B = - ' - ■ is and

C = I.

For convenience, these constants A and B have been given in the claims as ( '■ -) and - ( ' ■ -);

however, it can be seen that this is the same as B and A when z = 0.8862 K and every set consists of two objects. Thus, in the example described, where is the sample groups consist of the objects ^ and if an approved one. Difference between the declaration weight and the mean weight of 1.96 standard deviations is worked that

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Ratio of arms like 1: 0.224: 0.124, where ζ = 1.74. if working with a greater degree of certainty, where K amounts to three standard deviations, ζ = 2.66 and is the ratio of arms 1: 0.316: 0.216.

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Claims (6)

8/28/1973 -Patent claims Method for determining the maximum safety value of the declaration weight of a series of objects with a nominal declaration weight, characterized by forming a sample group from a predetermined number, preferably ten, of objects in the series, subdividing the objects of the group into subgroups with an equal number, preferably two, of objects, determination of the heaviest object and the lightest object in each subgroup, arrangement of all lightest objects on a first station of a scale, arrangement of all heaviest objects on a second station of the scale and carrying out a weighing with the help of the scale to determine the The difference between the product of the total weight of the lightest objects and ( ^ί -) and, which represents the maximum safety value of the declared weight the product of the total weight of the heaviest objects and ζ - 0 5 ( '■ -), where η is the number of objects in the sample group in the series and ζ is a constant dependent on the tolerated difference between the declaration weight and the average weight of the objects in the series. 2. Weighing device for performing the method according to claim 1, characterized by a beam balance with three weighing stations at different effective distances from a pivot point, these ^108812/0914 «14 - Distances to each other are in the ratio 1: { '- -): ( ^l -), at what ratio η is the number of objects in a Sample group in the series and ζ is a constant that depends on the tolerated difference between the declared weight and the Average weight of the items in the series is dependent. 3. Weighing device according to claim 2, characterized in that it has a second set of scales, which is used to distinguish the lighter ones Objects (L) from the heavier objects (S) in the subgroups formed from the sample group of objects is determined. 4. Weighing device after. Claim 3, characterized in that the constant η is an even number in the range eight to ten. 5. Weighing device according to claim 4, characterized in that the constant η is 10. 6. Weighing device according to claim 3, 4 or 5, characterized in that that the constant ζ is between 1.5 and 3. 409812/0914 Blank page