EP0416534A1 - Sleeve for a filling pipe to fill valve bags - Google Patents

Abstract

A sleeve for a filling pipe for filling valve bags has a spreading nozzle with preferably two nozzle segments (12) which are movable in relation to one another. With two nozzle segments, one of the nozzle halves (2) is arranged in a stationary manner while the other nozzle half (1) is pivotable. A movable clamping jaw (7) is provided for pressing one valve bag side against the outside of the stationary nozzle half (2).

Description

The invention relates to a filler neck for filler pipe for filling valve sacks with an expanding beak with two beak segments movable relative to one another.

Filling tubes, also called downpipes, are used to fill meterable materials, especially granular products, into valve bags. Plastic granules and fertilizers are primarily considered as materials, and to a lesser extent also granular products such as food, provided that they only contain a small amount of dust. The downpipes are usually arranged vertically in order to use gravity as a transport drive. However, there are also centrifugal valve filling machines, e.g. so-called centrifugal belt filling machines.

The valve sacks into which the products have to be filled are essentially rectangular when filled and have a filling opening, a so-called valve, adjacent to one end. Manually or with automatic slip-on machines, the empty valve bags are pulled with the valve onto a filler neck, which also forms the lower end of the filler pipe. A predetermined amount of the meterable material is then filled into the valve bag via the filling tube.

It is important that the valve bag is filled as completely as possible, i.e. a tight packing. Furthermore smooth filling must be made possible, since any smallest jam in an area of the filling pipe or in the area of the valve immediately leads to a build-up of material in the filling pipe. Any jam stops the further transport and the acceleration process of the material in the direction of the valve bag due to gravity must begin again. As a result, the packing density becomes insufficient and the filling speed also deteriorates considerably. It should be borne in mind that this is a process that must be repeated continuously and in which the filling times are in the range of approximately 5 seconds per filling process.

Known filler nozzles have an expanding beak with two movable halves. The two halves of the beak are moved symmetrically to each other. When at rest, they form a closed beak shape; a valve sack is pulled with its valve opening over the beak, then the expanding beak is opened, causing the outside of the two halves of the beak to strike against stops and clamping the valve sack on both sides.

A disadvantage of such a concept is that a filler neck is fixed to a certain diameter. If an attempt is made to pull a valve bag with a smaller valve diameter onto such a filler neck, the valve tears when it is opened. However, if the valve diameter is larger than the diameter of the filler neck in the open state, secondary air is created and the material to be filled is dusted out from the side. In addition, a clean, stable attachment and optimal, complete filling of the valve bag is then not possible

However, valve bags come in different sizes. The valve width, which is measured in practice with the valve laid flat, is approximately 100 to 180 mm, which inevitably results in the valve diameter. In addition, even with valve bags with a predetermined valve width, there are still certain manufacturing-related margins, which occasionally lead to valve bags of the correct size also not being able to be filled properly. The valve width must be variable so that product-specific tolerances given by the material to be filled can be taken into account.

The object of the invention is therefore to propose a filler neck for a filling tube for filling valve sacks with an expanding beak, preferably with two beak segments movable relative to one another, with which it is possible to react better to variable valve diameters.

This object is achieved in that one of the beak segments is arranged in a fixed manner and the other beak segments are pivotable, in that the opening angle between the beak segments of the filler neck is limited by the opening size of the valve of the valve bag, and in that a movable clamping jaw for pressing a valve bag side against the Outside of the fixed beak segment is provided.

With such a construction, the following sack attachment process is possible (based on a filler neck with exactly two beak segments or halves):

The valve bag is placed on the still closed filler neck (manually or automatically). Now the filling process is started. The movable beak half of the filler neck swivels about its axis and opens the valve of the sack so that the valve is open to the maximum. This means that the opening of the filler neck is influenced and determined by the size of the valve. The pneumatics or other opening controls can be set on a movable half of the beak to operate up to a predetermined maximum resistance. In the case of two halves which are movable relative to one another and which are moved symmetrically to one another in accordance with the prior art, this is not possible or is only possible with difficulty.

This means that almost all valve sizes of conventional dimensions can be processed with one and the same filler neck. It is no longer a question of any manufacturing tolerances for the valve widths. The diameter of the opening of the opened filler neck is round for the smallest valve diameters, and a round oval, elongated shape is formed as the valve diameter increases.

The movable clamping jaw can act with greater forces against the outside of the fixed half of the beak, since this can offer good resistance here. In conventional filling nozzles according to the prior art, the stop against which the movable half of the beak meets must be fixed or at least assume a predetermined maximum stop position, since otherwise unfavorable forces, which form torques about undesirable axes, would result from the various pneumatic cylinders which occur at different points on the filling nozzle would attack. Corrections to this disadvantage are only possible with complex, costly, complicated and therefore relatively error-prone lever-joint constructions.

According to the invention, however, only two drives, preferably pneumatic cylinders, are provided which operate independently of one another, namely one drive for the movable jaw half and the other drive for the movable jaw for pressing a valve bag side against the outside of the stationary jaw half.

With such a construction, the mechanics of the filler neck drive are fundamentally simplified. Coupling mechanisms are no longer required, which previously had to coordinate the movement of the two halves of the beak in a complicated manner, which took place in different directions. Instead, two very simple drives are used.

However, there are still further advantages with the construction according to the invention. Previously, it was necessary to attach the valve bag so that the two halves of the beak pulled the valve apart into the two sides adjacent to the flat sides of the valve bag and clamped the bag there. The reason for this is as follows: There is only a possibility of clamping where the valve skin and the bag wall are directly adjacent. Since the valve is arranged parallel to a corner parallel to the longitudinal edge of the valve bag, the bag wall can theoretically be clamped against three sides of a filler neck located in the valve; namely from the long side next to the valve or from the two side surfaces. No access can be made from the theoretical fourth side, since the valve bag itself is arranged there with its interior, which is supposed to be filled during the filling process.

Two divergent halves of the beak, which are connected to ge meet and pinch the valve skin and in particular the valve bag wall between themselves and these stops, can therefore only access from the two side surfaces. This is also done in the prior art. Clamping from one side only was not possible with the resulting weights and forces, since the force exerted by the beak halves against the stops is limited if deformation of the movable beak halves or overloading of the pneumatic cylinders is to be avoided.

This problem no longer arises according to the invention. The separately driven jaw can act against the fixed half of the beak with great force, and it is therefore possible to make do with a single clamping side. This can be done from the long side of the valve bag.

This has the following very important advantage: During the filling process, the center of gravity of the valve bag shifts. Since it is suspended adjacent to its one corner, the portion of the valve bag located on the longitudinal side adjacent to the valve moves in the direction of this longitudinal side, so that a kink of the bag wall is formed in the region of the valve. If the bag is clamped to the filler neck from both sides, an area of the valve bag is created that cannot be filled. Although this area is not particularly large in relation to the total volume of the valve bag, it is, however, a constant endeavor in all such filling processes to achieve the best possible filling of the valve bag, in order to accelerate the filling process in this way and to ensure that the filled valve bags are available for storage Fill rooms particularly well. It also depends on small improvements to meet the demands of the bottling plants.

Clamping from the longitudinal side of the valve sack allows the sack side walls to move past the filler neck to a small extent, but is available. The interior of the valve bag in this area can therefore also be occupied by the filling material. Only the area occupied by the clamping jaw adjacent to the long side is required to hold the valve bag. However, this room is much smaller.

This is accompanied by another advantage. When the sack falls off by loosening the clamping jaw and moving the two halves of the beak together, a rather approximate circular radius of the valve remains in the sack walls due to the lower clamping forces. The sack comes off more easily without any lateral movements.

Valve bags are generally filled using suction hoods, since a certain amount of dusting cannot be avoided. When the valve sacks were attached manually, the operator had been exposed to a certain amount of dust-like filling material in the air despite the suction hoods. When attaching, he had to stand in front of the filler neck so that the two stops on the left and right were in front of him. He could only pull the valve sack over the nozzle from the front, as this was prevented from the side by the stops. Now the valve bag closed tightly on the side of the stops, but the material could escape to a certain extent on the front facing the operator, especially since the two halves of the beak have their overlap zone on this side. Attempts are being made to achieve tightness here by overlapping beak halves, if only to optimize the filling process, however, this area is the most likely to release secondary air.

According to the invention, however, the operator can pull the valve bag onto the filler neck such that it is on the side facing away from the clamping jaw. There is now no disturbing mechanics, stops or the like. In addition, there is the back of the movable half of the beak. Any secondary air that would now be generated would at best be able to escape from the valve bag opening on the left and right in front of the operator and would therefore no longer flow directly to him. The nuisance can therefore be extracted through the extraction hoods before it reaches the operator.

The jaw is preferably provided with a pneumatic cylinder. This drive option is particularly reliable and, because it is common parts, also inexpensive.

The clamping jaw pressing against the fixed half of the beak or the fixed beak segment can be provided with several buffers if valve bags with sensitive, relatively thin-walled bag walls are to be provided, for example in the case of paper bags. This increases the total pressure area and also the angular pressure range of the jaw on the fixed half of the beak with the valve bag side part in between and prevents tearing or damage when the valve bag approaches its optimal filling level.

The expanding beak preferably has exactly two beak halves or segments. In principle, it is also possible to work with, for example, three or four beak segments, which together form the lower end of the filler neck. This will increase the costs, of course, and the mechanics become correspondingly more complicated, although under certain circumstances a more even spreading of the valve in the valve bag can take place.

In particular with only two halves of the beak, it is preferred if each half of the beak has an approximately semicircular cross section in its upper part adjacent to the filling tube and in the lower region adjacent to the opening end changes into a U-shape, in which the U-bend is in relation to the U-sides is significantly extended. With such a cross-sectional shape of the beak halves, a much better spreading of the valve of the valve sacks is possible. The halves of the beak are still closed when they are inserted into the valve. If the half-cylinder shape continued to the tip of the beak halves, they would actually end there in a tip or at least in a cone-like stump, which would lead to an elongated thin opening when the valve was inserted and spread apart. However, this would severely hinder the filling flow and lead to congestion and, in extreme cases, to the inability of the filling nozzle.

The design according to this preferred embodiment, however, permits an approximately uniformly rectangular spreading of the valve and thus an unimpeded optimal filling of the valve bag.

The filling pipes are usually designed as vertical downpipes. However, the design of the filler neck according to the invention can also be used with inclined or horizontal and even with slightly upward-extending fill pipes. In this case, the fixed half of the beak or the fixed beak segment, which is to be secured with the clamping jaw, would be preferred arranged on the upper side of the horizontal or inclined filling tube. This advantageously accommodates the weight distribution and the forces exerted by the filling valve bag and in turn leads to an optimal filling of the valve bag.

Basically, with the invention, the valve bags can also be set up or opened with less work or more quickly and easily. So far, namely, the operator had to reach into the valve with both hands in order to open it and to be able to insert the two halves of the beak which are movable relative to one another. In the idle state, they had to be inserted into the valve so that they were inserted with their larger extension, i.e. parallel to the swivel axis, parallel to the two largest side surfaces of the valve bag, and that means that they were perpendicular to the normal folded opening of the valve had to be inserted. As a result, this had to be deployed before the filler neck could be inserted.

With the invention, this is no longer necessary. Now the filler neck in its rest position is inserted exactly into the slot of the folded valve and automatically expands it slightly during the insertion process. The final spread then arises with the spreading of the beak segments.

The valve bag can thus be attached with one hand by the invention, which was practically impossible in the prior art. In this way, when transferred to an automatic feeder, there is no mechanism for opening the valve beforehand.

An exemplary embodiment of the invention is described in detail below with reference to the drawing.

• Fig. 1 einen erfindungsgemäßen Füllstutzen im Ruhe­zustand;
• Fig. 2 den Füllstutzen aus Fig. 1 im Zustand während des Füllens, zur Verdeutlichung ohne Ventilsack;
• Fig. 3 eine schematische Darstellung einer Füllsta­tion mit Füllstutzen gemäß Fig. 1 im Ruhezustand;
• Fig. 4 die Station aus Fig. 3 mit angehängtem lee­rem Sack;
• Fig. 5 die Station aus Fig. 3 kurz vor Beendigung des Füllvorganges;
• Fig. 6 die Station aus Fig. 3 unmittelbar nach Been­digung des Füllvorganges;
• Fig. 7 die Füllstation aus Fig. 3 beim Abfallen des
• Ventilsackes und
• Fig. 8 die Füllstation aus Fig. 3 während des Abtranspor­tes des Ventilsackes.

Show it:

• 1 shows a filler neck according to the invention in the idle state;
• FIG. 2 shows the filler neck from FIG. 1 in the state during filling, for illustration without a valve bag;
• FIG. 3 shows a schematic illustration of a filling station with filling nozzle according to FIG. 1 in the idle state;
• FIG. 4 shows the station from FIG. 3 with an empty sack attached;
• FIG. 5 shows the station from FIG. 3 shortly before the filling process has ended;
• FIG. 6 shows the station from FIG. 3 immediately after the filling process has ended;
• Fig. 7, the filling station of Fig. 3 when the
• Valve bags and
• Fig. 8, the filling station of Fig. 3 during the removal of the valve bag.

A fill pipe, not shown, opens into a filler neck with an expanding beak, the core of which is two beak halves 1 and 2. The two halves of the beak are movable relative to one another. A valve bag can be opened at its lower end (see Fig. 4).

The two beak halves 1, 2 are arranged on a fixed holder 3. The bracket 3 is in turn firmly connected to a structure 4 and a housing 5. A pneumatic cylinder 9 is articulated on the housing 5, which is supported on one side on the housing 5 and on the other side engages with its piston on a set-up lever 6. The lifting lever 6 is articulated at a distance from the point of application of the pneumatic cylinder 9 with a pivot axis 12. The pivot axis 12 runs approximately horizontally and through the holder 3. The pneumatic cylinder 9, which is below the bracket 3 is arranged, thus causes a pivoting movement of the positioning lever 6 about the pivot axis 12 by stretching. The positioning lever 6 is also connected to the movable half of the beak 1. When pivoting about the pivot axis 12, the beak half 1 is also pivoted in this way and moved relative to the fixed beak half 2.

The two possible extreme positions can be seen in FIGS. 1 and 2. In the case of Fig. 1, the pneumatic cylinder is retracted and the two halves of the beak are closed. This position is the rest position of the filler neck outside of the filling process. The valve bag can be opened in this position.

2 shows the position during the filling process with the halves 1 and 2 of the beak apart.

Another pneumatic cylinder 8 is provided, which is also supported on the housing. Its piston 7 ends in a buffer 10. This buffer, for example made of rubber or another elastic material, can be pressed against the outside of the fixed half of the beak 2 when the cylinder is actuated. A valve sack pulled over the two halves of the beak 1 and 2 is thus clamped. Figures 3 to 8 show schematically the sequence of a filling process. Below the filler neck there is a receiving device for the filled valve sack, for example equipped with a shaking device, as well as devices for tipping and conveying the filled sack. Initially, this support is still inoperative. An empty, largely folded valve bag will still stand together the two halves of the beak 1 and 2. The operator stands in the picture of the figures to the right of the filler neck and can attach the valve bag with one hand.

The filling process is then started, whereby the pneumatic cylinders 8 and 9 extend and the buffer 10 of the piston 7 presses the valve bag wall against the fixed half of the beak 2 and the pneumatic cylinder 9 pivots the lifting lever 6 with a fastening strap around the pivot axis 12, so that the half of the beak 1 moved away from the beak half 2 and the valve is spread.

The still empty valve sack is shown in FIG. 4 as a rectangle. During the filling process, of course, its weight increases and it moves in the direction of the arrow, that is to say clockwise in the image in FIG. 4, around the contact point of the buffer 10 against the outside of the fixed half of the beak 1.

Finally (Fig. 5) the valve bag is filled and is then supported on the bottom of the vibrator. Despite the now diagonal position of the valve bag, there are no more empty spaces shielded by kinks in the bag. The triangular spaces to the left and right of and slightly above the beak halves are also filled, as they are accessible to the filling materials.

Now the valve bag is separated from the filler neck by moving the two pneumatic cylinders 8 and 9 back again. The buffer 10 of the piston 7 thus releases the valve bag wall and the two halves of the beak 1 and 2 move back to their rest position and allow the valve of the valve bag to close again.

Due to its own weight, the valve bag according to FIG. 7 now falls counterclockwise around its lower support point and can be removed according to FIG. 8, for example by a conveyor belt. The type of release has the effect that the fastenings are loosened exactly in the desired direction of fall of the valve bag and thus facilitate falling. It should be taken into account that the halves of the beak are preferably designed such that they form a U at the bottom in cross section with a very wide U-shape and in this way assume the shape of a square to a rectangle with rounded corners when spread apart. When moving together, only the shape of this rectangle changes.

Claims (5)

1. Filling nozzle for filling tube for filling valve bags with an expanding beak with preferably two relatively movable beak segments, characterized in that one of the beak segments (2) is arranged in a fixed manner and the other beak segments (1) can be pivoted such that the opening angle between the beak segments the filler neck is limited by the opening size of the valve of the valve bag, and that a movable clamping jaw (piston 7) is provided for pressing a valve bag side against the outside of the fixed beak segment (2). 2. Filler neck according to claim 1, characterized in that the clamping jaw (piston 7) is provided with a pneumatic cylinder (8). 3. Filling neck according to claim 1 or 2, characterized in that the clamping jaw (piston 7) is provided with a plurality of buffers for increasing the pressure surface when pressing the valve bag side against the outside of the fixed beak segment (2). 4. Filling neck according to one of the preceding claims, characterized in that the filling pipe runs horizontally or slightly obliquely and the fixed beak segment (2) forms the top of the expanding beak. 5. Filler neck according to one of the preceding claims, characterized in that the beak segments (1,2) form the shape of a U in cross section, the arc of the U being longer than the sides.

Images