Method and device for controlling the amount of filling material in a weight-responsive filling machine.

MEMORY

MCG, ρ "· -79,130 ​​toj« »nim

The present invention relates to container filling installations, and; more especially, a method and a device for dosing container filling material in a weight-filling filling machine.

The weighting is increasingly imposed in filling facilities with liquid or divided materials, for example in the food or pharmaceutical industries, due to obtaining more accurate and more reliable results with respect to the volumetric dosing facilities. This technique requires the provision, for each filling head, of a weighing scale associated with detection means for actuating the filling head according to the weight of the filling material actually supplied. Up to now, due to the severe conditions of use of such materials, a means of detecting the type of proximity detection was envisaged, associated with a mobile element of the balance, as described in French Patent No. 2,098,780 a name of the inventor.

07121 p- · '79 «15O _sa η2 78/1737 3 name of the applicant.

The purpose of the present invention is precisely to propose a method and a device for dosing container filling material in weight-filling filling machines, obviating the aforementioned drawbacks, which offers, while retaining a high reliability in use, a great flexibility of utilization, integrating programmable logic components, and allowing to modulate the operating conditions of the installation, already injecting image data of specific parameters, already automatically in operation.

To this end, the method according to the present invention, carried out in a filling machine, which comprises at least one filling / weighing station with a filling head, a weighing machine in parallelogram, with detection means associated therewith. The weighing device for actuating the filling head consists in mechanically coupling a mobile element of the balance device, a force sensor, and in continuously transmitting the output signal of the sensor to a programmable logic memory unit, that supplies a signal of command^-at the filling head, when the detected weight value reaches a value deducted and corrected from the registered nominal value.

According to another characteristic of the present invention, the dosing device for said filling machine, more especially but not exclusively of the type of rotating platform or carrousel with multiple posts, comprising at least one filling station with a

07121

79,130

IhijH ηιΊπΓ2 "',

- Operable filling head and a weighing scale of equipment in paralyogram, with detection means being associated to the weighing balance to provide a control signal to the filling head, comprising a force sensor mechanically coupled to a mobile element of equipment the balance, and linked to a first input of a programmable logic memory unit, comprising a second command and memory entry, and whose output is linked to the filling head.

In addition to the problems of severe conditions of use, as regards temperature and humidity, filling machines, mainly of the carousel type, have so far proved rebellious. The integration of electronic components, mainly due to the high levels of vibration in wide ranges of frequency found in such machines. The applicant, by virtue of his experience of several years in the field of the dosage ponderal, and after numerous experiences, has verified that the use of a force transducer, for example of the type of tension indicator, could only be carried out in association with a weighing machine balance in paraelomogram, whose robustness and ability to fit the parasite pairs inevitably induced on the measuring plate in high-speed installations, however, authorized, thanks to the small inertia of these scales, equipped with articulation bearings, extremely fine measuring capacities. Indeed, mainly in the filling carousels, in addition to the inertial problems due to the rotating character of the installation, the containers,

07121

79.150 i Íojh núm ** *

I <

for example, the bottles, to be correctly positioned below the filling heads, are dynamically located, in the course of their loading, on the filling carousel, by centering flanges, such as those shown in figure 1, and then transmit Pairs important and variable parasites to the weighing equipment, which make illusory, due, in addition, to the important variations of location of the center of gravity of the container, a direct mechanical coupling between the receiving / weighing plate and a force transducer.

According to another characteristic of the present invention, since the force sensor -ύθΐ ΐίρο of sensitive sheet and of voltage indicator, the mechanical coupling between^- the sensor and the mobile element or beam of the equipment of the balance, is made by a traction cable.

In fact, due to the aforementioned vibration percentages, the applicant has verified that the output signal of a transducer operating in compression was almost unusable in a filling machine, while the tension in tension, more especially by a flexible cable, allows decrease the effects of vibrations on the sensitive sheet of the sensor by a factor of 10.

Other features and advantages of the present invention will be apparent from the following description of an embodiment, given by way of illustration but not limiting, made in connection with the accompanying drawings, in which:

Fig. 1 is a schematic sectional view of a weighing station of a filling carousel with a dosage of weight, equipped with a device according to the

07121

Ρr> f> τ ύ5 · -> Ε present invention; Y

Figure 3 is a plan view of said filling installation, which allows to appreciate the sequences of the dosing control procedure with the device of figure 1.

In Figure 2, a multi-station filling carousel 1 is recognized, fed from containers to be filled by an upstream transfer carousel?, Which takes the containers 3 onto a linear conveyor 4-, the containers being filled in the carousel of filling 1, stolen to the latter, and spare parts in circulation on the linear conveyor by an output transfer carousel 5 »The filling carousel 1 is provided with a certain number of weighing stations (typically 12 or 24-) of the type shown in FIG. Figure 1

In this figure 1, the filling head 6 is recognized, for example of the electromagnetic valve control type, arranged vertically of a dish or receiver 7 of a weighing scale of the parallelogram equipment type, generally designated with the reference 8

The balance 8 is composed of a carrier column 9, mounted on a frame 10, integral with the hollow shaft 11 of the carousel, a floating column 11, and a lower shaft 12, the parallelogram being completed by an upper crossbeam 13, these being different elements articulated with respect to one another by means of ball bearings, such as that shown at 14-. According to the present invention, the balance 8 'has a particularly compact configuration, with the average height of the upper or double columns of the length of the sleepers. The plate

07121 p_ 79 »190 • 20

07121

Nîtrn sheet- »Q« ·· * «· i

_7 is linked to the floating column 11 by a hollow tubular pillar 15 ·

at the level of the neck of these bottles and inducing the problems of parasite pairs mentioned. If balance equipment 8 can be completed by a counterweight 24, mounted on an extension of the shaft 12, although this counterweight induces problems of inertial torques, which require a mass compensation to the other side of the balance, said counterweight not being necessary with the force sensor according to the present invention.

The force transducer 25, comprising a sensitive sheet 26 of tension indicator, is mounted on a stirrup 27, which is sensitive to the extension of the upper cross-piece 13, the stirrup 27 being fixed, by the inner ends of its lateral arms, to him ρ_ 79,130

07121

<img file="ES8300057A1_D0001.tif" />

i

- support column 9. According to the present invention, this support column 9 is, furthermore, fixed to the frame 10, with interposition of elastic elements in elastomer 23, for example of the type called Silent-Slock.

The sensitive sheet 26 of the sensor 25 is mechanically coupled to the outer end of the shaft 12, by a cable 28, which normally exerts traction on the sensitive sheet, in a direction perpendicular to the plane thereof. According to one aspect of the present invention, the cable 23 passes through the hole of the sensitive sheet 26 and a helical spring 29, at the upper end of the neck is connected the adjacent end of the cable 28, the spring 29 being supported by a profiled bowl on the sheet 26.

The spring 29 is of the high stiffness type and is designed to begin to crush, under the application of a compression force of the order of 20 kg, ie, widely greater than the normal weight of the containers filled to weigh by the balance. For weights of measuring vessels of the order of 2 to 5 kg, the sensor 26 is chosen with a sensitive sheet of the class of 20 kg. To avoid any accidental deterioration of the sensitive sheet, the angular displacement towards the lower part of the shaft 12 is limited by an adjustable stop 20. FIG. .

According to the present invention, the output of the force sensor 25 is routed by a line 31 to a measurement input 32 of a microprocessor programmable logic unit 35 »housed in a support with a shock absorber below the balance equipment 8. logical memory unit 35 comprises, at least, a second input 34-, which allows the injection into the data memory

Ρ- 79,150

07121 determined, and the enrollment of certain program steps. A calculation output 55 of the logic unit 55 is connected by a line 57.3 to the filling head 6, for selectively actuating the opening and closing according to conditions developed by the logic unit 55, typically when the weight value measured by the sensor, converted to numeric, reaches an internal value displayed.

The procedure, of. Dosage control according to the present invention will now be explained more in detail, with reference to the implementation scheme of figure 2. At the beginning of a filling cycle, the data of this cycle, mainly the desired weight values according to the type of products to be filled, and the dimensions of the containers, they are injected by the input 54- in the logical units 55 of the scales of the different filling positions of the carousel 1. Let us suppose, for example, that the desired weight of the Container filling material is 1000, -gives. With the method of the invention, there is no concern to carry out in advance an average determination of the sizes of the containers to be filled, nor that of the average value of the column of liquid or of. split product mentioned in the introduction part of the description. A desired initial value less than the required weight, for example 900 grams, is simply adapted to the logic units 55}. A first step of containers supplied by the linear conveyor 4 allows, for the successive filling stations, that the associated sensors 25 transmit to the corresponding logical units 55, in the course of the first phase of p-79,150

07121 ^one 1 slab no. J \

- angular transfer AB from loading area A, (angle AB of the order of 15 3 202), measurement signals that make them take into account the tare weight constituted by each container, which allows to adjust the records of the logic unit 53 psra which can carry out a continuous measurement in net weight in the course of the angular transfer phase BC, upstream of the discharge zone B, that is, before structural elements of the transfer carousel 5j begin. get in contact with the containers. If angle 0% is chosen in the order of 10 to 15- · Depending on the voluntarily reduced calibration of this starting cycle, the logic unit 53 will have supplied, by its output 55, a closing signal of the head 6,

Ρ_ -79-3-30!

ίο

II «jh nítnf * ν '^-»« · A 5 grams.

The method according to the present invention allows, in addition, to take into account the undesired quantities of materials on the plates 7, coming, for example, from leaks of previous containers and to actuate, for an outlet 57? an alarm and / or display device, which signals the malfunction of a head, as detected during the comparison phase, in the transfer phase.

Although the present invention has been described in relation to special embodiments, it is not limited to them, but is, on the contrary, susceptible to modifications and variants that will arise for the technician.

07121 kij «m'tm-H-