Device for dosing a fill product into a container to be filled

Abstract

A device for dosing a fill product into a container is described. The device includes a dosing unit with a dosing cylinder, a dosing piston displaceably disposed in the dosing cylinder between an upper center and a lower center of the dosing cylinder, and an intake valve with a valve seat for sucking the fill product from a rotatable product reservoir. The valve seat is disposed above a level formed by a base of the dosing piston at the lower center.

Claims

1. A device for dosing a fill product into a container comprising: a dosing unit with a dosing cylinder; a dosing piston displaceably disposed in the dosing cylinder between an upper center and a lower center of the dosing cylinder; an intake valve with a valve seat and a valve disk sitting on the valve seat configured to suck the fill product from a rotatable product reservoir, wherein the valve seat is disposed above a level formed by a base of the dosing piston at the lower center and the intake valve is configured to be opened by lifting the valve disk out of the valve seat into the rotatable product reservoir, wherein the rotatable product reservoir is configured to provide the fill product to the intake valve; a product channel that connects the intake valve and the dosing cylinder, wherein a longitudinal axis of the product channel is inclined in relation to a longitudinal axis of the dosing piston; and an outlet valve configured to eject the fill product from the dosing cylinder, wherein the outlet valve is in fluid connection with the dosing cylinder, the intake valve and the outlet valve are switchable using mechanical switching cams, and the mechanical switching cams are pneumatically controlled.

2. The device of claim 1, wherein the valve seat is disposed substantially horizontally.

3. The device of claim 2, wherein the valve seat is connected horizontally to the rotatable product reservoir.

4. The device of claim 1, wherein the intake valve and the dosing cylinder are in fluid communication with each other via the product channel.

5. The device of claim 4, wherein the product channel extends with an upward inclination to the intake valve.

6. The device of claim 1, further comprising a bellows to seal moveable parts of the intake valve against the fill product.

7. The device of claim 1, wherein the dosing unit is disposed on an underside of the rotatable product reservoir.

8. The device of claim 1, wherein the valve seat is mounted on a base plate of the rotatable product reservoir.

9. The device of claim 1, wherein the dosing unit has a modular construction and is configured to be connected to the rotatable product reservoir as a ready-to-function unit.

10. The device of claim 1, wherein the mechanical switching cams are switchable using switching means that are fixed or activatable, the switching means disposed on a stationary part of the device, as the switching cams make passing contact.

11. The device of claim 1, wherein the rotatable product reservoir comprises a base plate, and the dosing unit is fixedly attached to the base plate such that the intake valve is substantially flush with an inner side of the base plate.

12. The device of claim 11, wherein the valve seat of the intake valve is substantially flush with the inner side of the base plate.

13. The device of claim 1, wherein a direction of operation of the intake valve is along an axis that is parallel to a stroke axis of the dosing piston and parallel to an axis of rotation of the rotatable product reservoir.

14. A device for dosing a fill product into a container comprising: a dosing unit with a dosing cylinder; a dosing piston displaceably disposed in the dosing cylinder between an upper center and a lower center of the dosing cylinder; an intake valve with a valve seat and a valve disk sitting on the valve seat configured to suck the fill product from a rotatable product reservoir configured to provide the fill product to the intake valve, wherein the valve seat is disposed above a level formed by a base of the dosing piston at the lower center, the intake valve is configured to be opened by lifting the valve disk out of the valve seat into the rotatable product reservoir, and the valve seat is disposed horizontally on a side of the rotatable product reservoir; a product channel that connects the intake valve and the dosing cylinder, wherein a longitudinal axis of the product channel is inclined in relation to a longitudinal axis of the dosing piston; and an outlet valve configured to eject the fill product from the dosing cylinder, wherein the outlet valve is in fluid connection with the dosing cylinder, the intake valve and the outlet valve are switchable using mechanical switching cams, and the mechanical switching cams are pneumatically controlled.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Further embodiments and aspects of the present invention are more fully explained by the description below of the figures.

(2) FIG. 1 is a schematic sectional representation of a first embodiment of a device for dosing a fill product;

(3) FIG. 2 illustrates a second embodiment of a device for dosing a fill product; and

(4) FIG. 3 is a representation of a detail of a dosing unit mounted on the product reservoir according to FIG. 2.

DETAILED DESCRIPTION

(5) Examples of embodiments are described below with the aid of the figures. In the figures, elements which are identical or similar, or have identical effects, are designated with identical reference signs, and repeated description of these elements is in part dispensed with in the description below, in order to avoid redundancy.

(6) FIG. 1 shows a device 1 for dosing a fill product into a schematically shown container 100 that is to be filled. The device 1 serves in particular to dose viscous and/or paste-like fill products into the container 100, in order to introduce a predetermined volume of the fill product into the container 100 within a specified time.

(7) The fill product to be dosed is held in a product reservoir 2, and dosed into the container 100 by means of a dosing unit 3.

(8) The dosing unit 3 has a dosing cylinder 30, in which is displaceably disposed a dosing piston 32 which can be moved upwards and downwards in the dosing cylinder 30 by means of a linkage 34 between an upper center and a lower center T.sub.u. The upward and downward movement of the dosing piston 32 in the dosing cylinder 30 thereby creates a cavity that is variable in size below the base 320 of the dosing piston 32. When the dosing piston 32 is raised, a partial vacuum is created by the cavity, and by means of this the fill product is sucked from the product reservoir 2. When the dosing piston 32 moves downwards, the fill product is ejected into the container 100 that is to be filled.

(9) The supply of fill product from the product reservoir 2 is achieved by means of an intake valve 4, which is directly connected to the base plate 20 of the product reservoir 2. The intake valve 4 has a valve seat 40, which is disposed substantially horizontally in operation. The valve disk 42 for sealing or opening the intake valve 4 sits on the valve seat 40. In the example embodiment shown in FIG. 1, the horizontally disposed valve seat 40 is substantially flush with the base plate 20 of the product reservoir 2. Accordingly, fill product that is held in the product reservoir 2 can pass via the intake valve 4 through the valve seat 40 and via a product channel 5 to reach the underside of the dosing piston 32, by means of which it is sucked into the dosing cylinder 30.

(10) In order to dose a fill product accommodated in the product reservoir 2, the intake valve 4 is first opened. (In the example embodiment shown, this is carried out by lifting the valve disk 42 out of the valve seat 40.) The dosing piston 32 is then raised in the dosing cylinder 30, causing the fill product in the product reservoir 2 to be sucked through the intake valve 4 and the product channel 5 into the dosing cylinder 30.

(11) At the upper center of the dosing piston 32, the intake valve 4 is again closed by lowering the valve disk 42 into the valve seat 40. When the dosing piston 32 is subsequently lowered, the volume of fill product in the dosing cylinder 30 is ejected via the fill product outlet 60 into the container 100. An outlet valve 62 is provided in the form of a double-acting pneumatic cylinder, by means of which the fill product outlet 60 can be opened and closed. When the fill product is being sucked out of the product reservoir 2 and the intake valve 4 is open, the outlet valve 62 is closed, so that the suction created by the rising dosing piston 32 can act to full effect on the fill product in the product reservoir 2.

(12) When the fill product accommodated in the dosing cylinder 30 is being ejected by lowering the dosing piston 32, the intake valve 4 is closed and the outlet valve 62 is open, in order to direct the stream of fill product exclusively through the fill product outlet 60.

(13) The intake valve 4 and in particular the valve seat 40 are disposed at a level E.sub.1, which, when the dosing unit 3 is in its installed state, lies above the level defined by the base 320 of the dosing piston 32 at its lower center T.sub.U. Consequently, an air cushion or gas cushion that has formed below the base 320 of the dosing piston 32 can be pushed, at least at the lower center T.sub.U of the dosing piston 32, via the product channel 5 and the intake valve 4 back into the product reservoir 2. The air or gas thus flows away from this lower center T.sub.U of the base 320 of the dosing piston 32 and via the product channel 5 and the intake valve 4 into the product reservoir 2.

(14) The product channel 5 is in various embodiments inclined upwards towards the intake valve 4, in order also to prevent an air cushion or gas bubbles from accumulating in the product channel 5. Instead, these will also be ejected through the intake valve 4 back into the product reservoir 2.

(15) In this manner it is also possible, at the start of production, to carry out the full ventilation of the dosing cylinder 30, such that no gas or air remains below the base 320 of the dosing piston 32. During production, it is further possible to eject at the lower center T.sub.U via the intake valve 4 any accumulations of gas or air that would form an air cushion below the dosing piston 32.

(16) In this manner, the dosing accuracy of the dosing unit 3 is increased, since the dosing volume thereby consists to a high degree, or even completely, of the fill product, and inaccuracies due to the presence of an undefined volume of air or gas (which is furthermore compressible) are avoided.

(17) The valve disk 42 of the intake valve 4 is raised and lowered by means of a valve rod 44, which is itself actuated by means of a pneumatic valve actuator 46. The moveable parts of the intake valve 4 are sealed against the fill product and/or the environment by means of a bellows 48.

(18) As is immediately clear from FIG. 1, a product stream flows around the bellows 48 of the intake valve 4 such that the product stream impinges on the bellows 48 in an axial direction. The flow around and/or over the bellows 48 is therefore in a longitudinal direction. The bellows 48 is in several embodiments composed of polytetrafluoroethylene (PTFE), or else it is designed as a metallic bellows. The orientation of the bellows 48 such that the flow around the bellows 48 is in a longitudinal direction enables lower-wear operation, since it avoids the substantially transverse flow around the bellows that is known from the state of the art, in which the intake valve is arranged radially. Accordingly the bellows 48 in the example embodiment shown is subject to significantly reduced transverse mechanical loads. Furthermore, it is more difficult for, for example, fibrous components of the fill product to become trapped between the folds of the bellows, since they are flushed out during the outflow of the product, and are also more easily captured during cleaning. The flow around the bellows 48 that is shown thus leads to reduced stress due to alternating load conditions in comparison with the substantially perpendicular incident flow according to the state of the art. The use of suitable materials for the bellows 48, for example the use of PTFE, reduces the thermal and/or chemical components of the wear parameters.

(19) The arrangement of the valve seat 40 in a horizontal position and in some embodiments, substantially flush with the base plate 20 of the product reservoir 2 further enables the loss of product at the cessation of production to be reduced compared to the conventional radial arrangement of the intake valve. In particular, the intake of fill product can continue for as long as the intake valve 4 is still covered by fill product. Premature sucking in of air, such as was known with the radial intake valves in their upper valve area, does not occur with the intake valve 4 due to its horizontal orientation. Residues in the product reservoir 2 can accordingly also be substantially emptied via the dosing units 3.

(20) Removal of residues can, for example, be carried out if a collection device, into which the product residues from the product reservoir 2 are pumped, is disposed specifically for this purpose below the product outlet 60.

(21) In the example embodiment shown, both the actuator 46 of the intake valve 4 and the actuator of the outlet valve 62 are pneumatically controlled. The compressed air required for this is conveyed to the dosing unit 3 via a pressurizing medium channel 22 incorporated in the base plate 20 of the product reservoir 2, with the connection provided by means of suitable drilled holes in the body which forms the dosing unit 3. It is thereby possible to dispense with elaborate tubing or ducting, since the insertion of the dosing unit 3 in itself typically results in the connection of the applicable connecting holes with the pressurizing medium channel 22.

(22) The intake valve 4 and the outlet valve 62 are switched by means of mechanical switching cams 70, 72, which are actuated by control elements (not shown in FIG. 1) that are fixedly attached to, or can be pneumatically activated on, the non-rotating part of the device 1. Thus at certain rotational positions or at certain working angles of the device 1 as it rotates, the applicable switching cam 70, 72 is actuated such that either the intake valve 4 is opened or closed, or the outlet valve 62 is opened or closed. The mechanically controlled switching cams 70, 72 enable a simpler mechanical construction, which dispenses with elaborate control of the intake valve 4 and/or the outlet valve 62 in the rotating part of the device 1.

(23) When control elements are used which can be activated pneumatically to engage with the switching cams 70, 72, it is possible additionally to achieve the exclusion of specific dosing units 3, which can then, for example, be activated or deactivated selectively. Furthermore, by this means one or more dosing units can be selectively opened to empty residues from the product reservoir 2 at a specific position.

(24) In the base plate 20 of the product reservoir 2, not only a pressurizing medium channel 22 but also an air outlet channel is generally provided, by means of which the used compressed air from the valve actuators of the intake valve 4 and the outlet valve 62 can be intercepted before it reaches the areas where it would come into contact with the product.

(25) In the example embodiment shown, the valve rod 44, which lowers or raises the valve disk 42 of the intake valve 4 in the valve seat 40, is oriented parallel to the direction of stroke X of the dosing piston 32. The direction in which the outlet valve 62 is opened and closed is also arranged in the direction of stroke X. The direction of stroke X is also parallel to the axis of rotation R of the product reservoir 2 during the production process.

(26) The fact that the valve rod 44, and the direction in which the intake valve 4 is opened and closed, are oriented parallel to the direction of stroke X of the dosing piston 32 also makes it possible in a simple manner to achieve the removal of residues from the product reservoir 2, as well as the reliable ejection of gas residue below the base 320 of the dosing piston 32. This is in particular the case if the valve seat 40 is above the lower center of the base 320 of the dosing piston 32.

(27) The dosing unit 3 in an exemplary embodiment has a fully modular construction, such that the dosing unit 3 can be attached to the base plate 20 of the product reservoir 2 as a ready-to-function unit, and forms a self-contained functional unit. In order to replace it, for example in the event of a defect, the entire dosing unit 3 can be removed and replaced by another. By this means, maintenance and/or repair times can be reduced.

(28) The outlet valve 62 can be designed as a diaphragm valve, as a pinch valve, or as a seat valve.

(29) The valves can be controlled by electropneumatic, pneumatic, electromagnetic or electromotive means, using for example servomotors, pneumatic actuators or stepper motors.

(30) The outlet valve 62 can be designed, for example, in the form of a pneumatic cylinder, wherein the stroke of the outlet valve 62 is variable by mechanical means, for example stroke limiters that can be inserted and replaced manually, or by pneumatic means, for example a double-stage cylinder.

(31) FIG. 2 shows a further device 1, which again has a product reservoir 2, a dosing unit 3 with a dosing cylinder 30, and a dosing piston 32. An intake valve 4 is also provided, whose valve seat 40 is again disposed at a level E.sub.1, which lies above the lower center T.sub.U of the dosing piston 32. The intake valve 4 is connected with the dosing cylinder 30 via a product channel 5 which is inclined upwards. An outlet valve 62 is also provided.

(32) The design shown in FIG. 2 corresponds substantially to the design that is also known from FIG. 1.

(33) In FIG. 2 it can also be seen that a plurality of dosing units 3 are provided, which are disposed on the periphery of the product reservoir 2.

(34) The linkage 34, which is connected with the dosing piston 32, is controlled by means of a positive guide in the form of a cam control system with a cam roller 36, which runs in a corresponding control curve 38. The control curve 38 is retained on the stationary frame 8 of the device 1.

(35) In the example embodiment shown, the switching cams 70, 72 are controlled at the applicable angular positions by mechanical switching means 74, which are disposed on the stationary frame 8.

(36) FIG. 3 shows a schematic enlargement of a detail of a dosing unit 3 with a connection to the product reservoir 2 according to FIG. 2.

(37) The valve seat 40 is disposed substantially flush with the base plate 20 of the product reservoir 2, so that almost all residues of fill product can be removed from the product reservoir 2. It can be seen particularly clearly here that the product channel 5 is inclined and the base 320 of the dosing piston 32 is disposed at a level below that of the valve seat 40.

(38) It can further be recognized that the design of the bellows 48, 64 of the intake valve 4 and the outlet valve 62 is such that the flow around these is in a longitudinal direction.

(39) To the extent applicable, all individual features described in the individual embodiments can be combined with each other and/or exchanged, without departing from the field of the invention.