This invention relates to a filler device for a flexible bag. In the packaging industry, a conventional device for filling a bag with a product is an auger filler. The auger filler includes an auger screw communicating with a product feed hopper. As the auger screw rotates, it displaces a quantity of product along its axis into the bag. The user may vary the quantity of product displaced by the auger screw by varying the volume between the auger screw's flights and the number of revolutions of the screw.

There are problems with the auger filler. The auger screw contacts the product and is therefore particularly dangerous when used with ingestible products due to the likelihood of contamination. As the packaging industry opts for a more sustainable approach to packaging, flexible bags have become a more popular medium than the conventional rigid containers (such as jars) and the non-rigid containers (such as plastic bottles) as they use less material. However, the contamination issue associated with the auger filler is a major concern in the industry. It is therefore desirable to alleviate the problems associated with auger fillers.

According to a first aspect of the invention, there is provided a filler device, for filling a flexible bag with a solid fluent product, comprising a product feeder, for feeding the solid fluent product; a first chamber, for receiving the solid fluent product from the product feeder at a first end, and having an aperture at a second end; and a second chamber, for communication with the second end of the first chamber at a first end, and for communication with the flexible bag at a second end; wherein the second chamber includes a flap at the second end, the flap configured to move between a first state, wherein the second end of the second chamber is sealed, to a second state, wherein the second end of the second chamber is open.

Therefore, the filler device of the present invention may apply a vacuum to the second chamber when the flap is sealed in the first state, such that the solid fluent product flows through the aperture in the second end of the first chamber into the second chamber. Therefore, the second chamber fills up with the solid fluent product.

Once the second chamber contains a predetermined quantity of the solid fluent product, the flap may then move to the second state, such that the second end of the second chamber is opened, and the solid fluent product may flow out into the flexible bag.

Thus, the filler device of the present invention employs non-contact technology to fill flexible bags with a controllable volume of product. Flexible bags have not been used with conventional vacuum filling devices as they deform as the vacuum is applied. The present invention therefore alleviates the problem of contamination by virtue of contact technology, such as the auger screw.

Preferably, the second end of the second chamber is angled between 35° and 55° to the second chamber's longitudinal axis. Therefore, as the flap moves from the first state to the second state, there is less chance of particles escaping the main body of the solid fluent product. Therefore, in the event the bag is to be sealed after the solid fluent product has been introduced, the amount of particles caught in the seal may be reduced.

Advantageously, the second end of the second chamber is angled at 45° to the second chamber's longitudinal axis. This further decreases the likelihood of particles escaping the main body of solid fluent product.

The second chamber may have an internal taper, such that the second end of the second chamber is wider than the first end of the second chamber, the internal taper being between 1 ⁰ and 5°. With such an internal taper, the solid fluent product is more likely to flow out of the second chamber as a unit. Thus reducing the likelihood of particles moving out of the unit and, for example, being caught in the bag sealing process.

Advantageously, the second chamber has an internal taper, such that the second end of the second chamber is wider than the first end of the second chamber, the internal taper being 3 °. This further decreases the likelihood of particles moving out of the unit of solid fluent product and, for example, being caught in the bag sealing process.

Preferably, the filler device includes a seal groove on a face of the second end of the second chamber.

Embodiments of the invention will now be described, by way of example, and with reference to the drawings in which: Figure 1 is a front perspective view of a filler device of an embodiment of the present invention, where a left door and a front-left pillar in a first housing portion have been removed for illustrative purposes;

Figure 2 is a rear perspective view of the filler device of Figure 1 ;

Figure 3 is a rear perspective view of the filler device of Figure 1 , where a rear wall and a rear cabinet have been removed for illustrative purposes;

Figure 4 is a cross-sectional view of the filler device along line A-A of Figure 1 ;

Figure 5 is a cross-sectional view of the filler device along line B-B of Figure 1 ;

Figure 6 is a perspective view of a metering chamber of the filler device of Figure 1 ; and Figure 7 is a cross-sectional view of the metering chamber along line C-C of Figure 5.

A first embodiment of a filler device 1 of the present invention will now be described with reference to Figures 1 to 7. The filler device 1 includes a first housing portion 3, a second housing portion 5, a hopper 10, a vacuum chamber 20, a metering chamber 30 and a funnel 40. As shown in the cross sectional views of Figures 4 and 5, the hopper 10, vacuum chamber 20, metering chamber 30 and funnel 40 are disposed axially such as to define a path from the hopper 10 to the funnel 40.

In this embodiment, the hopper 10 is a gravity feed hopper of tapered conical form. The hopper 10 stores a quantity of solid fluent product therein, such as powdered or granulated product. The hopper 10 is substantially disposed outside the first housing portion 3. The hopper 10 has an opening at a first end thereof such that the product may be introduced to the filler device 1 . The hopper 10 also has an opening at a second end thereof, communicating with the vacuum chamber 20 in the first housing portion 3, such that the product may flow from the hopper 10 to the vacuum chamber 20 under gravity. The hopper 10 may also include a lid (not shown) to close the opening at the first end thereof, to ensure no contaminants enter the filler device 1 .

As shown in more detail in the cross-sectional views of Figures 4 and 5, the vacuum chamber 20 includes an opening at a first end thereof, communicating with the second end of the hopper 10 in order to receive the flow of product. The vacuum chamber 20 includes an aperture 22 and a vacuum gauze 24 at a second end thereof.

In this embodiment, the vacuum gauze 24 also communicates with a vacuum means (not shown), via an air conduit 26, in order to increase or decrease the pressure inside the metering chamber 30. When the air pressure inside the metering chamber 30 is substantially at atmospheric pressure, the product flows down to the second end of the vacuum chamber 20 and bridges the aperture 22. However, as the air pressure inside the metering chamber 30 is reduced to a vacuum, the 'powder bridge' across the aperture 22 is broken and the product may flow through the aperture and into the metering chamber 30.

The metering chamber 30 includes an opening at the first end, communicating with the vacuum chamber 20 at the second end thereof, for receiving the product. The metering chamber 30 also includes a flap 35 at a second end thereof. The flap 35 is moveable from a first state, wherein the flap 35 seals the second end of the metering chamber 30 such that a vacuum may be applied therein, and a second state, wherein the flap 35 breaks the seal and opens the second end of the metering chamber 30 such that the product may flow out into the funnel 40 in the second housing portion 5. The second end of the metering chamber 30 includes a sealing groove 32. As shown in more detail in Figures 6 to 7, the metering chamber 30 includes an internal taper a, such that the cross sectional area of the first end of the metering chamber 30 is smaller than the cross sectional area of the second end of the metering chamber 30. In this embodiment, the angle of the internal taper from the first end to the second end is around 3°. Therefore, if a quantity of product is stored within the metering chamber 30, and then drops out under gravity, the quantity of product is more likely to fall out as a single body, i.e. there is less chance of individual particles of the product escaping from the body. In the event that the quantity of product falls into a bag, which is to be sealed (as described below), there is therefore less chance of escaping particles of product being caught in the bag sealing process.

Furthermore, in this embodiment, the second end of metering chamber 30 is angled at around 45° to the metering chamber's 30 longitudinal axis. As shown in Figure 4, the flap 35 seals the second end of the metering chamber 30 at this angle when in the first state. Therefore, as the flap 35 moves to the second state, such that the second end of the metering chamber 30 is open, it is more likely that the powder within the metering chamber 30 will fall out as a single unit (compared to a metering chamber having a second end angled at 90° to the metering chamber's longitudinal axis). This is because, in this embodiment, the flap 35 moves away from the opposing and adjacent sides of the metering chamber 30 (i.e. the left and right sides respectively as shown in Figure 4) at substantially the same time (or at least more effectively than when the second end of the metering chamber is angled at 90 ° to the metering chamber's longitudinal axis).

Thus, the angle of the second end of the metering chamber 30 ensures that the powder may tumble out of the metering chamber 30 substantially as a single unit. Therefore, again, if the powder drops out of the metering chamber 30 under gravity, there is less chance of individual particles of the product escaping from the single unit. In the event that the quantity of product falls into a bag, which is to be sealed (as described below), there is less chance of escaping particles being caught in the bag sealing process.

The skilled person will therefore understand that the internal taper and the angle of the second end of the metering chamber 30 both have the effect of reducing the likelihood of individual particles of product being caught in a bag seal. Thus, the quality of the bag is improved.

In this embodiment, the flap 35 is connected to a first motor 37. The first motor 37 is configured to cause the flap 35 to move between the first and second state. As shown in Figure 4, the flap 35 is rotated about a rotation point 39 adjacent the metering chamber 30. The funnel 40 includes a first cylindrical portion at a first end thereof, and a second cylindrical portion at a second end thereof, surrounding a tapered portion. In this embodiment, the first cylindrical portion is wider than the second cylindrical portion and includes a catch to removably attach the funnel 40 to an underside of the first housing portion 3. The funnel 40 ensures that any particles escaping the flow of product is guided down towards its second end, or at least sticks to the side of the funnel 40.

The second end of the funnel 40 is adapted to communicate with a bag.

The skilled reader will understand that the filler device 1 of the present invention will mostly be used on production lines for producing sealed bags containing the product. Preferably, the production line includes a load cell, for measuring the sealed bags weight after they have been filled using the filler device 1 . If the weight of the sealed bags is not within an allowable tolerance, then a signal is fed back to the filler device 1 to vary the amount of product. To vary the amount of product, the filler device 1 includes a second motor 28, which is configured to receive the signal from the load cell, and drive the vacuum chamber 20 up or down in response to the signal. This has the effect of raising or lowering the level of the vacuum gauze 24 respectively. The skilled reader will understand that this will vary the amount of product that flows into the metering chamber 30, as the flow of product stops as it reaches the level of the vacuum gauze 24. Therefore, to reduce the amount of product dispensed by the filler device 1 , the second motor 28 causes the vacuum chamber 20, and thus the vacuum gauze 24, to move down in response to the signal from the load cell, and vice versa. The skilled person will understand that other forms of varying the amount of product dispensed by the filler device 1 are possible.

A method of setting up the filler device 1 will now be described. Initially, the flap 45 is moved to the first state to seal and cover the second end of the metering chamber 30, wherein the pressure is at atmosphere. Fluent product is introduced to the hopper 10, which flows down to the second end of the vacuum chamber 20, where it bridges the aperture 22.

A method of using the filler device 1 will now be described. For the following description, the functioning of a web dispensing and a bag sealing device will also be described. However, the skilled reader will understand that the web dispensing and the bag sealing device are substantially conventional, and alternatives may be used. The web dispensing device dispenses a length of web underneath the second end of the funnel 40. The web is cylindrical, initially having a first and second open end, wherein the first end of the web communicates with the second end of the funnel 40. The web is sealed at the second end, a predetermined distance from the first end, thus forming a bag. Therefore, the product may flow out of the second end of the funnel 40, into the first end of the bag.

The flap 35 of the metering chamber 30 is moved to the first state and its internal pressure is at atmosphere (the skilled reader will understand that this is already the case following set- up). Therefore, the product bridges the aperture 22 at the second end of the vacuum chamber 20.

The vacuum means then decreases the pressure in the metering chamber 30 to substantially create a vacuum therein. Therefore, the powder bridge at the aperture 22 is broken and the product flows into the metering chamber 30. The product abuts the flap 35 at the second end of the metering chamber 30, and fills it up until it reaches the level of the gauze 24 of the vacuum chamber 20.

When the product reaches the level of the gauze 24, it blocks the vacuum and stops the flow of product. The product therefore re-bridges the aperture 22.

At this point, the first motor 37 causes the flap 35 to move to the second state. Thus, the second end of the metering chamber 30 opens and the product is able to flow out of the metering chamber 30. Therefore, in normal use, the product falls under gravity, through the funnel 40, and into the bag. The pressure inside the metering chamber 30 therefore returns to atmosphere.

The bag sealing device then seals the bag at the first end. A cutting device separates the bag from the remainder of the web, and the web dispensing device dispenses another length of web, to be sealed at the second end thereof, and the method is repeated. The skilled person will understand that this is a continuous process, forming a plurality of bags containing the fluent product. The skilled person will understand that the filler device could be adapted as a multi-head device, that is, the device could employ several vacuum chambers and metering chambers, working in conjunction with a single web dispensing and bag sealing device. In such an arrangement, the product would be dispensed sequentially from each metering chamber into a bag, whilst a separate metering chamber is being filled. Thus, the efficiency of the machine is increased. The 'multi-head' filler device may use a single hopper communicating with each vacuum chamber, or may employ several hoppers communicating with each vacuum chamber. Similarly, the 'multi-head' filler device may use a single funnel communicating with each metering chamber, or may employ several funnels communicating with each metering chamber.

The skilled person will also realise that the gravity hopper is not essential to the invention, and that other forms of product feeder may be used instead, for example, vacuum conveyors. The foregoing description describes a filler device for filling a flexible bag with a solid fluent product, such as a powder or granulated product. The skilled person would understand that this device is suitable for both free-flowing and non-free flow products. However, in the case of non-free flow products, the device may be adapted to speed up the rate of flow of the product. For example, vibration actuators may cooperate with the major components of the device.

The skilled person will also understand that the features of the metering chamber 30 having an internal taper and having an angled second end are non-essential. However, these features are preferable, as they improve the flow characteristics of the product as the flap opens and the product flows out.

The skilled person will understand that any combination of features is possible without departing from the scope of the invention, as claimed.