Apparatus for Filling Containers According to Weight

Abstract

The invention relates to an apparatus for the weight-dependent filling of containers, especially bottles (3), which comprise a tubular neck section (7) and which consists of a fill nozzle (8), a weighing device (5) and a holding element (6) for holding the container (3) under the fill nozzle (8). In that regard the weighing device (5) includes a force uptake element (14), a force introduction element (15) and a deformation body (17, 18) that is arranged therebetween and that is provided with strain gages (24) applied thereon. In that regard, the force uptake element (14) is secured on a machine frame (2) and the holding element (6) is secured on the force introduction element (15). The invention is characterized in that the force uptake element (14) is embodied as an outwardly lying ring element (14) and the force introduction element is embodied as a coaxially inwardly lying ring element (15), between which at least one radially spring-elastic connecting web (17, 18) is arranged as the deformation body. In that regard, the holding element (6) is secured on the inwardly lying ring element (15) therebelow.

Description

The invention relates to an apparatus for the weight-dependent filling of containers, especially bottles according to the preamble of the patent claim 1.

In the beverage industry, large quantities of containers, especially bottles of glass or plastic, are filled with beverages or other liquid foodstuffs in very short time segments. Also in other branches of industry it is often necessary to fill determined quantities of liquids into containers with screwable fill openings. For that purpose, mostly automatic filling equipment stations are used, which are embodied as carousel or rotational filling machines especially in the beverage industry. In that regard, the containers or bottles are directed from a supply belt onto a circulating path or track on the circumference of the rotational filling machine, on which a plurality of filling nozzles or filling stubs are arranged uniformly distributed above the circulating containers. During the circulation on this rotational filler, then valves located in the filling nozzles are opened and again closed upon reaching a prescribed fill level. Thereafter, the filled and closed containers leave the circumferential area of the rotational filler and are further conveyed with a relatively high uniform speed via an outlet conveyor belt.

Such a rotational filling equipment station is known from the EP 0 893 396 B1, which is provided for the automatic filling of plastic bottles with a liquid. In that regard, the bottles are directed onto the circulating path on the circumference of the filling equipment station respectively under a filling nozzle with a fill valve, whereby the bottle neck is fixed by a holding element under the filling nozzle. During the rotational circulation or revolution, now the fill valve is opened and the liquid is let into the bottle until apparently a prescribed quantity is filled-in. In this regard, it apparently relates to a volumetric filling, which is not suitable for all liquids or bottles.

A weight-dependent filling is known from the DE 698 08 118 T3, which provides an outwardly flaring or collared weight determination and holding support of a bottle under a filling nozzle. Thereby similarly a filling equipment station of a carousel type is provided, which discloses a rotatable platform for the filling of the bottles. This filling apparatus is provided exclusively for plastic bottles that comprise a laterally protruding circumferential collar around the cylindrical neck under their pipe-shaped or tubular fill opening. For this, a weighing device is provided, which includes a bending beam weighing or load cell. This is embodied as a double bending beam, which consists of an elongated square-section rod, into which two throughgoing horizontal bored holes are laterally let-in, and are connected with one another by a recess lying therebetween. The lateral horizontal bored holes form two thin locations at the beam upper side and beam lower side, which represent a deformation body, onto which strain gages for determining the weight force are applied. In that regard, the one horizontal end of the clamped-in bending beam represents a force output element, which is connected with the frame of the rotating filling equipment station. The oppositely lying end of the bending beam thereby represents the force introduction element, onto which a holding element is secured. In that regard, the holding element extends laterally outwardly flared or collared away from the bending beam and from the frame of the filling apparatus. In that regard, the holding element consists of two horizontal, laterally rotatably supported flat jaws, which are held together by means of a spring and which comprise a round opening on its outwardly flared or collared end. Regarding the supplied bottles, these are guided with their neck or throat into the opening in such a manner, so that the collar lies on the upper jaw surface, so that the bottles are fillable while freely suspended in the holding element. For filling the bottles, a filling nozzle is arranged above the opening, and after opening a valve the liquid is filled into the bottle through the filling nozzle. Due to the support of the collar on the jaws of the holding element, during the rotating filling process, the weight force is introduced into the force introduction element of the weighing device, which is rigidly clamped-in relative to the frame of the filling equipment station. Thereby a strain is produced in the deformation body, which is proportional to the weight of the bottles, and which is detected by the strain gages. Upon reaching a prescribed fill weight, then the inflow through the filling nozzle is stopped and the filling process is ended. Such a filling apparatus has the disadvantage, that it is only suitable for the filling of plastic bottles with a collar that extends around the neck, and requires a laterally large structural space for the arrangement of the rod-shaped load cell.

From the DE 39 04 714 A1, however, also a force measuring ring is known, which requires only a small outwardly flaring or collared structural space. This force measuring ring consists of two ring elements that are arranged coaxially within one another, whereby the upper inner ring element is connected radially with the outer lower ring element by two movable bending springs as deformation bodies. For detecting the force introduced into the upper ring, the bending springs are equipped with strain gages. Even if this force measuring ring comprises a throughgoing hollow central opening, it is not apparent how it would be usable for the filling of containers according to weight.

Therefore, it is the underlying object of the invention to provide an apparatus for the weight-dependent filling of containers, which requires only a small outwardly flaring or collared structural space and is also usable for containers or bottles without collars.

This object is achieved by the invention set forth in patent claim 1. Further developments and advantageous example embodiments of the invention are set forth in the dependent claims.

The invention has the advantage that the central inner annular hollow space can be used for leading through the filling liquid, due to the ring-shaped or annular embodiment of the weighing device. Thereby a very compact filling apparatus can be achieved, which can be constructed short both in its axial length as well as in the outwardly flaring or collared area, and advantageously requires only a small structural space, which barely extends beyond the diameter of the container to be filled.

The invention further has the advantage that no lever arm acts on the measuring element due to the symmetrical arrangement of the holding element on the inner ring of the weighing device, so that the weighing device is not at the same time overloadable even with larger filling pressure jolts or peaks. The largely rotationally symmetrical embodiment of the weighing device additionally has the advantage that thereby a high weighing accuracy can be achieved, because due to the central holding support and filling of the liquid into the container, only small interfering bending moments can act on the measuring arrangement or compensate one another due to the symmetrical arrangement.

The invention additionally has the advantage that due to the central and axial arrangement of the holding element below the weighing device, thereby all containers with central filling openings are fillable in a weight-dependent manner, whereby it does not depend on the presence of a collar on the container.

Simultaneously, such a holding support centrally below the weighing device has the advantage that therewith also containers having various different lengths are fillable, without adjustments of the filling apparatus being necessary for that. With a correspondingly adapted holding element, therefore weight-dependent fillings of glass bottles with crown cap necks or threaded necks as well as of plastic bottles with only a threaded neck are also possible, and this with a high filling accuracy.

In a particular embodiment of the weighing device it is provided to enclose the radial internal area between the two ring elements at the top and the bottom by a simple flexurally soft cover. This has the advantage that thereby a hermetic sealing of the inwardly arranged sensitive measuring elements is possible, without a separate housing being necessary for that. With a particular embodiment of the flexurally soft cover, additionally still a coaxially encircling load relief groove is provided, whereby even small interfering force shunt effects are also reducible.

The invention is explained in more detail in connection with an example embodiment, which is illustrated in the drawing, wherein:

FIG. 1 shows a cutaway section of a filling equipment station with a filling apparatus mounted thereon;

FIG. 2 shows a perspective plan view onto an upwardly open weighing device;

FIG. 3 shows a perspective plan view onto a downwardly open weighing device; and

FIG. 4 shows a perspective sectional view through a hermetically sealed weighing device.

In FIG. 1 of the drawing, there is illustrated a cut-away section of a carousel filling equipment station 1 and mounted thereon, an apparatus for the weight-dependent filling of bottles 3 as containers. The apparatus includes a weighing device 5 screwed onto a rotor plate 4, on which weighing device, a holding element 6 is arranged thereunder and a fill nozzle or pipe stub 8 is guided from the top axially throughgoing to the bottle neck 7 centrally through the weighing device 5.

The carousel filling equipment station 1 includes a machine frame 2 which rotates during the filling operation, and on which a rotor plate 4 is arranged as a part in an overhanging or collar-protruding manner at the top. A fill pipe 9 is arranged from a liquid container, which is not shown, on the machine frame 2 to each filling apparatus spaced apart on the circumference of the rotor plate 4, whereby the fill pipe 9 is guided through the rotor plate 4 and centrally through the weighing device 5, and the fill nozzle or pipe stub 8 thereof ends above the fill opening on the bottle neck 7. The filling apparatus may, however, also be provided on a linear filling equipment station.

A U-shaped holding bail 10 is provided as the holding element 6, wherein the holding bail is open radially to the supply or infeed direction of the bottles 3 and comprises two horizontally oriented parallel shanks 11. In that regard, the upper shank 11 is tightly screwed onto the bottom side of the weighing device 5 and has a through passage opening for guiding through the fill nozzle 8. The lower shank 11 of the holding element 6 preferably comprises a recess that is open toward the front and that corresponds to at least the diameter of the bottle neck 7. However, embodiments with clamping jaws and adaptations for fixing on a threaded rim or on a crown cap rim are also usable as the holding element 6.

The illustrated embodiment with the recess open toward the front is provided for the resting contact of the collar 12 situated on the bottle neck 7, as it is typical in current commonly used plastic bottles. During the filling of the bottles 3 or other containers with a central upper cylinder-shaped fill opening, due to the weight of the bottle 3 and the respective contents thereof, the gravimetrically downwardly acting weight force F_G is introduced via the holding element 6 into the weighing device 5. Upon reaching a prescribed weight force F_G as the filling weight, then a valve, which is not shown but which is situated in the fill pipe 9, is closed so that the filling process is ended and, for example, a bottle 3 filled with a beverage can be further conveyed for closing it.

The weighing device, which is screwed from the bottom onto the rotor plate 4 of the machine frame 2, is shown in detail in FIG. 2 and FIG. 3 of the drawing. In that regard, FIG. 2 of the drawing shows a weighing device 5 open toward the top, with the four symmetrically arranged through-bores 13 provided for the screw-connection. In that regard, the weighing device 5 is embodied as an essentially rotationally symmetrical load cell that comprises, as a force uptake element 14, a radially outer ring element as a narrow outer ring. In that regard, the load cell 5 is machined as one piece out of a short massive round rod by a chip-removing machining process, and therefore has only a small hysteresis. In that regard, the base body 38 produced thereby preferably consists of a spring-elastic stainless steel alloy, aluminum or titanium. The base body could, however, also be produced of ceramic in PIM technology (Powder Injection Molding) or in MIM technology (Metal Injection Molding), which would have to be ground after the powder injection molding process so as to maintain accurate dimensions.

A radially inwardly lying ring element as a force introduction element 15 is arranged as an inner ring lying coaxially inwardly relative to the outer ring 14, wherein the inner ring surrounds or encloses a cylinder-shaped central hollow space 16, through which the fill nozzle 8 is guided through in a contact-less manner. Preferably two radial connecting webs 17, 18 are machined out of a previously remaining intermediate ring 19, between the outer ring 14 and the inner ring 15, on a horizontal center plane 31, wherein the connecting webs 17, 18 represent the two deformation bodies lying 180° radially opposite one another, by which the force uptake element 14 is connected with the force introduction element 15 of the load cell 5 in a spring-elastic manner.

For that purpose, an axially through-going outer ring groove section 20 is milled into the previously solid intermediate ring 19 in the area of the outer ring 14 on a circumferential range or region of approximately 235°, and lying 180° radially opposite thereto in the area of the inner ring 15 a further axially through-going inner ring groove section 21 of similarly approximately 235° is milled into the previously solid intermediate ring 19. Thereby, a first connecting web 17 and lying 180° radially opposite thereto a second connecting web 18 have arisen between the overlapping ring groove sections 20, 21, whereby the connecting webs connect the outer ring 14 and the inner ring 15 radially with one another and extend on a respective tangential ring web section 34 of approximately 60° concentrically to the inner ring 15. Two parallel transverse grooves 22 with a semicircular cross section are milled into these two oppositely located concentric ring web sections 34 of the connecting webs 17, 18 from the top side of the load cell 5. These respectively form two thin locations 23 in the connecting webs 17, 18, and respectively two strain gages 24 as sheer stress transducers are applied on the opposite planar web surface thereof, as this can be seen in more detail from FIG. 3 of the drawing.

In that regard, FIG. 3 of the drawing shows a side of the load cell 5 that is open toward the bottom. In that regard, the load cell 5 is embodied on its bottom side approximately symmetrically to the top side, whereby however no transverse grooves 22 are milled into the web bottom sides 25. Thereby the strain gages 24 can be applied very exactly on the planar surfaces of the thin locations 23.

For mounting the holding bail 10, the inner ring 15 is provided with a widened wall thickness toward the bottom side and with four symmetrically distributed threaded bored holes as securing bores 26. Furthermore, the outer ring 14 is flattened in a narrow area of its outer circumferential surface, where a sealed cable inlet 27 is arranged for the connection of the weighing electronics and the strain gages.

The connection to the weighing electronics via the cable inlet 27 is visible in detail from FIG. 4 of the drawing, which illustrates the load cell 5 as a side view in section. This FIG. 4 simultaneously shows a particular embodiment of the invention in which the weighing electronics 33 is integrated in the load cell 5 and the inner space is hermetically closed by two membrane-like covers 28, 29. In that regard, in FIG. 4 of the drawing, the load cell 5 is illustrated reversed relative to the installation position, whereby the bottom side of the load cell 5 is sealed by a flexibly elastic lower membrane-like cover 28, which is arranged between the outer circumference of the inner ring 15 and the inner circumference of the outer ring 14 and is hermetically tightly welded therewith. In a similar embodiment and arrangement, also the upper cover 29 is applied or installed on the oppositely lying load cell side. In that regard, the covers 28, 29 preferably consist of a membrane-like thin stainless steel sheet metal of approximately 0.1 mm thickness, which is well weldable with the edges or rims of the ring elements 14, 15. For improving the weighing accuracy, especially for reducing a possible force shunt effect, a concentric load relief groove 30 with a triangle-shaped or semi-circular cross section is impressed or embossed into each cover 28, 29, whereby the groove comprises a radial flexurally soft structure.

Moreover, still additionally a radially encircling holding ring 32 is applied on one side on the inner wall of the outer ring 14 above the horizontal center plane 31, and an electronic circuit board 33 with the weighing electronics is secured on this holding ring 32. Hereby the strain gages 24 are circuit-connected preferably to form a Wheatstone measuring bridge, are supplied with a supply voltage, amplify the measuring signals, digitize the measuring signals and modulate the measuring signals for transmission. The transmission can also be carried out with a bus system. In a different embodiment of the filling apparatus, the weighing electronics is integrated in the connecting cable.

The filling process in the filling equipment station 1 proceeds as follows.

In rapid succession, the bottles 3 are delivered from a supply belt to the carousel filling equipment station 1, and with their collars 12 are hung into the holding bail 10 of the holding element 6 in a manner freely suspended or floating under the fill nozzle 8. Then during the rotational turning of the rotor plate 4, by opening an inlet valve the bottle 3 is continuously filled. Thereby the weight is introduced via the holding bail 10 into the inner ring 15 as the force introduction element, of which the force effect produces a maximum strain in the thin locations 23 of the connecting webs 17, 18. This is proportional to the weight force F_G, and it is converted by the strain gages 24 into an electrical weight signal and transmitted to an evaluating circuit. There, during the filling process, this weight signal is compared with a prescribed filling weight, and upon reaching it the filling process is ended. The above described load cell 5 involves a highly accurate calibratable embodiment preferably with a nominal weight range of 10 kg and an accuracy of +/−0.5 g to +/−1.0 g.

With such a filling apparatus, preferably beverages are filled into plastic bottles having a 1.0 to 1.5 l content volume, whereby therewith also bottles 3 and containers from 0.33 to 5.0 l content volume are fillable with calibratable accuracy. The illustrated embodiment of the load cell 5 with a nominal load of 10 kg in that regard preferably has an outer diameter of approximately 90 mm and a height of approximately 40 mm. Thereby the load cells 5 can be arranged next to one another approximately at the bottle diameter of 1.5 l bottles 3 about the rotor plate 4, in order to be able to simultaneously fill the largest possible number of bottles 3 or containers.

The central hollow space 16 of the inner ring 15 preferably has a diameter of 27 mm, so that thereby typical fill nozzles 8 for conventional bottle openings can be guided therethrough, so that a rapid filling is ensured, without there being a danger of contacting the force introduction element 15. With such a load cell 5, with corresponding dimensioning of the deformation bodies 17, 18, it is, however, also possible to produce embodiments with smaller nominal loads of for example 2 kg and larger nominal loads of for example 50 kg. In that regard, the weight-dependent filling apparatus is not only usable for liquids, but also for friable or flowable or dust-type fill materials.

In the embodiment of the holding element 6, not only mechanical holding bails 10 for the resting contact of a bottle collar 12 are usable, but rather all embodiments in which the container is fixable symmetrically to the fill opening 8. Thus, also electrical, hydraulic, pneumatic or magnetic clamping systems are conceivable, by which the bottle necks, container threadings, or cans can be held centrally under the fill nozzle 8.

Claims

1. An apparatus for the weight-dependent filling of containers, especially bottles (3), having a tubular neck section (7), wherein the apparatus comprises a fill nozzle (8), a weighing device (5) and a holding element (6) for holding the container (3) under the fill nozzle (8), and in which the weighing device (5) includes a force uptake element (14), a force introduction element (15) and a deformation body (17, 18) arranged therebetween and with strain gages (24) applied on the deformation body, whereby the force uptake element (14) is secured on a machine frame (2) and the holding element (6) is secured on the force introduction element (15), characterized in that the force uptake element is embodied as an outwardly lying ring element (14) and the force introduction element is embodied as a coaxial inwardly lying ring element (15), between which at least one radially spring-elastic connecting web (17, 18) is arranged as the deformation body, whereby the holding element (6) is secured to the inwardly lying ring element (15) therebelow.

2. The apparatus according to claim 1, characterized in that the fill nozzle (8) is guided from the top through a central hollow space (16) of the weighing device (5) at least to the fill opening of the container (3).

3-16. (canceled)

17. The apparatus according to claim 1, characterized in that the weighing device is embodied as a rotationally symmetrical load cell (5), which includes a one-piece base body (38), which consists of the inner ring (15) and the coaxially surrounding outer ring (14) and the at least one connecting web (17, 18) arranged radially therebetween.

18. The apparatus according to claim 17, characterized in that the one-piece base body (38) consists of a spring-elastic stainless steel, aluminum, titanium or ceramic.

19. The apparatus according to claim 1, characterized in that the outer ring (14) and the inner ring (15) are connected with one another in a frictional or force-coupling manner by two connecting webs (17, 18) lying radially 180° opposite one another in a horizontal center plane (31).

20. The apparatus according to claim 1, characterized in that each connecting web (17, 18) consists of a first radial web section (35) that is connected with the inner ring (15) and a second radial web section (36) that is connected with the outer ring (14), and a tangential ring web section (34) lying therebetween.

21. The apparatus according to claim 20, characterized in that each tangential ring web section (34) comprises two tangentially spaced-apart transverse grooves (22), which form two spring-elastic thin locations (23), on which strain gages (24) are applied.

22. The apparatus according to claim 21, characterized in that the connecting webs (17, 18) are formed by two axially throughgoing ring groove sections (20, 21) that lie radially opposite one another, whereby an inner ring groove section (21) extends on the inner ring (15) and an outer ring groove section (20) extends on the outer ring (14).

23. The apparatus according to claim 22, characterized in that both ring groove sections (20, 21) extend on a radial angular range of the load cell (5) of approximately 235° and overlap one another on their ends on a range of approximately 60°, whereby the tangential ring web sections (34) extend on a tangential angular range of about 60°.

24. The apparatus according to claim 1, characterized in that the load cell (5), symmetrically to its longitudinal axis (37), comprises a throughgoing central hollow space (16), which serves for the contact-less through-guidance of the fill nozzle (8).

25. The apparatus according to claim 1, characterized in that the outer ring (14) and the inner ring (15) are hermetically tightly connected at their axial end areas with a lower cover (28) and an upper cover (29).

26. The apparatus according to claim 25, characterized in that the covers (28, 29) respectively consist of a membrane-like thin metal sheet, which is welded to the ring elements (14, 15).

27. The apparatus according to claim 25, characterized in that the covers (28, 29) comprise at least one load relief groove (30), which is impressed or embossed therein concentrically to the inner ring (15), and which has a radially flexurally soft structure.

28. The apparatus according to claim 1, characterized in that at least one holding ring (32), which is secured on one side on the outer ring (14), is provided in the inner space of the load cell (5) above or below a center plane (31), and an electronic circuit board (33) with a weighing electronics is secured on the holding ring.

29. The apparatus according to claim 1, characterized in that a sealed cable inlet (27) is arranged on a circumferential surface of the outer ring (14), which serves for the connection of the weighing electronics or regarding which the weighing electronics is integrated in the connection cable.

30. The apparatus according to claim 1, characterized in that the holding element (6) is embodied as a radially outwardly open U-shaped holding bail (10), of which the lower horizontally oriented shank (11) has a radially outwardly open recess that serves for receiving the bottle neck (7) and/or for vertically fixing the container.