Apparatus and a method for expanding and simultaneously filling containers

Abstract

An apparatus for expanding plastic preforms into plastic containers by a liquid medium using at least one forming station that fills and expands the plastic preforms used in the liquid medium using at least one supply device that supplies the liquid medium to a filling device of this forming station, wherein this filling device is configured to fill the liquid medium into the plastic preforms, and wherein the apparatus has a pressure generation device that supplies the liquid medium under pressure to the filling device. The pressure generation device has at least two pressure generation units that are configured to provide the liquid medium under pressure to the filling device.

Claims

1. An apparatus for expanding plastic preforms into plastic containers using a liquid medium having at least one forming station that fills and expands the plastic preforms using the liquid medium using at least one supply device that supplies the liquid medium to a filling device of this forming station, wherein said filling device is configured to fill the liquid medium into the plastic preforms, and wherein the apparatus has a pressure generation device that supplies the liquid medium under pressure to the filling device wherein the pressure generation device has at least two pressure generation units configured to provide the liquid medium under pressure to the filling device.

2. The apparatus as claimed in claim 1, wherein the two pressure generation units are connected in parallel in such a way that they each supply the liquid medium to the filling device.

3. The apparatus as claimed in claim 1, wherein the two pressure generation units are each connected to the filling device via liquid lines.

4. The apparatus as claimed in claim 1, wherein the filling device has a collection space for receiving the liquid medium, which collection space is in fluid communication, at least temporarily, with each of the pressure generation units.

5. The apparatus as claimed in claim 1, wherein the pressure generation units each have drive units.

6. The apparatus as claimed in claim 1, wherein the pressure generation units each have a liquid chamber and a piston unit configured to be moved relative to this liquid chamber.

7. The apparatus as claimed in claim 1, wherein at least one pressure generation unit is a pump unit and in particular a pump unit that is selected from a group of pump units consisting of a hydraulic pump, a sinus pump, an axial piston pump, a bellows pump, a diaphragm pump, a scroll pump, a rotary piston pump, an eccentric screw pump, a screw conveyor, an impeller pump, a chain pump, an annular piston pump, a hose pump, a screw spindle pump, a shake pump, and a tooth belt pump.

8. The apparatus as claimed in claim 1, wherein the filling device comprises a closure element that blocks the flow of the liquid into the container in at least one position and allows this flow in at least one position.

9. The apparatus as claimed in claim 1, wherein the pressure generation device has a toggle lever.

10. A method for expanding plastic preforms into plastic containers by a liquid medium using at least one forming station that fills and expands the plastic preforms using the liquid medium, wherein the liquid medium is supplied to a filling device of the forming station using at least one supply device, wherein the filling device fills the liquid medium into the plastic preforms and wherein a pressure generation device of the forming station supplies the liquid medium under pressure, wherein the pressure generation device has at least two pressure generation units that provide the liquid medium under pressure to the forming station.

11. The apparatus as claimed in claim 1, wherein the pressure generation units drive units are configured to be controlled independently of each other.

Description

[0076] According to the invention, at least one element of the pressure generation device is prestressed, at least temporarily, by means of a prestressing unit. Further advantages and embodiments will become evident from the attached drawings, wherein:

[0077] FIG. 1 shows a grossly schematic representation of an apparatus according to the invention;

[0078] FIG. 2 shows a representation of a forming station according to the applicant's internal prior art;

[0079] FIG. 3 shows an representation of a forming station according to the invention;

[0080] FIG. 4 shows a further representation of the forming station according to the invention;

[0081] FIG. 5 shows a representation of a pressure generation device with a toggle lever;

[0082] FIG. 6 shows a representation of a forming station with a prestressing unit;

[0083] FIG. 7 shows a representation of a forming station with a hydraulic or pneumatic drive unit.

[0084] FIG. 1 shows a schematic representation of an apparatus according to the invention for forming and filling containers. This apparatus comprises a rotary carrier 12 on which a multiplicity of forming/filling devices is disposed. These forming devices are used, as mentioned above, for filling and expanding the plastic preforms at the same time with a container. Plastic preforms are supplied to the apparatus via a supply device 15 such as a supply star, and the finished and filled containers are subsequently transported off from the apparatus via a discharge device 17.

[0085] FIG. 2 shows a forming station 2 according to the applicant's internal prior art. Here, the actual filling device is provided, which has an application device 25 that can be applied to a mouth 10a of the plastic preform to be expanded, in order to fill and shape in this way the plastic containers 10. To this end, the forming device has an expansion mould 11, within which the plastic preforms are expanded into the plastic bottles or plastic containers. Reference numeral 26 identifies a filling housing, within which a closure device 24 such as a closure plug is provided. As a result of a movement of this valve body in the longitudinal direction L of the container, the supply of liquid into the container 10 can be regulated.

[0086] Reference numeral 22 identifies a so-called stretching rod that can be introduced into the inside of the containers, in order to stretch the latter in this way in the longitudinal direction thereof. To this end, the apparatus includes a drive unit 27 that is suitable and destined for moving the stretching rod in the longitudinal direction thereof.

[0087] Reference numeral 4 identifies in its entirety the pressure generation device that supplies the liquid under pressure to the plastic container. Here, the pressure generation device has only one pressure generation unit. This pressure generation means, more specifically the pressure generation unit, has a reception space 45, within which the liquid 47 to be filled in is provided. Apart from that, also supply lines may be provided which (for example starting from a reservoir, not shown) supply the liquid to the reception space 45.

[0088] Reference numeral 43 identifies a piston unit that is movable in the direction x, in order to transport in this way the liquid via a connection line 35 to the actual filling head (referred to above also as a filling device). Reference numeral 62 identifies the drive unit in particular in the form of a servomotor 63 that drives the movement of the piston unit 43. To this end, the drive unit generates a rotary movement that is output via an output shaft 64. Reference numeral 65 identifies a transmission unit, here a planetary gear, and reference numeral 66 shows a further output shaft. This output shaft in turn drives a linear spindle 67, which moves rod elements 68 and 69 which are connected to each other via a coupling and on which in turn the piston unit is mounted.

[0089] Therefore, in the embodiment shown in FIG. 2, the apparatus only has one single pressure generation device that has to apply the pressure for filling and expanding the containers. Reference numeral 32 identifies a pressure measuring device that measures a pressure occurring in the filling housing 26.

[0090] FIG. 3 shows an embodiment of an apparatus or a forming station 2 according to the invention. Here, the actual filling head is designed in a way similar to the embodiment shown in FIG. 2 and will therefore not be explained in more detail. Contrary to the embodiment shown in FIG. 2, however, two pressure application units 42 and 44 are provided here. These may be designed in the same way and have already been described above, so that this will not be repeated. It is possible for these pressure application units to operate simultaneously, however, they may also fill the containers with a liquid medium with a temporal offset. Apart from that it would also be possible for these two pressure application units 42 and 44 to receive different liquids in the respective reception spaces 47, so that for example a product mix may be supplied to the container 10.

[0091] FIG. 4 shows an embodiment in which a total of four pressure application units 42 to 44 are present, which are again connected to the actual filling device via connection lines. These four pressure generation units may contain several different products, for example four different products. In this case it would be possible that the drive force is again minimised and a product mix is filled in. It would be possible here that one product is present in each of these pressure generation devices, which is pressed into the plastic preforms to be formed either at the same time or sequentially. Here, the required drive output for one of these four pressure generation units may be significantly reduced compared to the power requirement where just one single pressure generation unit is used.

[0092] Apart from, or instead of, the above-described drive devices, however, also hydraulic drive units or motors with a nut integrated in the rotor and a spindle may be provided, which is for example implemented as a hollow shaft.

[0093] FIG. 5 shows a further embodiment of the present invention. In this embodiment, again two pressure generation units 42 and 44 are provided, however only the actual filling devices are shown here. In this embodiment, just one drive of the above-identified type, but in addition a lever means 50 is provided, which transfers the forces thus generated to the piston unit 43. This lever unit is here implemented as a so-called toggle lever that is hinged onto the two piston units 43 so as to move the latter. In this case, the required forces are applied using a toggle lever. The pressure profile during the forming of the containers requires here a rapid moulding process and, when the bottle is nearly finish-formed, a short travel path and large holding forces.

[0094] FIG. 6 shows a further embodiment of the present invention. In this embodiment, the actual filling device is designed in a way similar to the above-mentioned filling device. Also, the drive device 62-69 is designed in a way similar to the one above and will therefore not be described here. Additionally, however, the apparatus shown in FIG. 6 has a prestressing unit or a preloading unit 7, which prestresses the piston device 43 downwards in the direction x. In the embodiment shown here, this prestressing unit has a reservoir 72, in which for example air can be stored under a predetermined pressure. This air can be fed into the space 78 via a connection line 74 and a valve 76. In this reception space, the pressurised air can additionally load the piston means 43, so that this is urged downwards.

[0095] Thus, in the embodiment shown in FIG. 6, the area of attack or the region of attack for the prestressing unit is the rear side of the piston means 43.

[0096] FIG. 7 shows a further embodiment of the apparatus according to the invention. In this embodiment, too, the actual filling device is designed in the way shown above. Here, too, a reception space 47 and a piston unit movable relative to this reception space are present. The embodiment shown in FIG. 7 is different with regard to the type of drive for the piston unit. As a drive unit, a hydraulic or pneumatic drive unit is used here. To this end, a hydraulic chamber 94 is provided again, in relation to which a piston element 92 is also movable in the direction x. Reference numeral 98 identifies a piston rod which in turn is coupled to the piston unit 43 by means of a coupling device.

[0097] Reference numeral 82 identifies a valve that can be switched in a controlled manner. By means of an accurate switching of this valve 82, a volume could be adjusted in a time-controlled manner. In addition, also mechanical stops or a modified volume flow of a pump could conceivably be provided within this drive unit 90. Reference numeral 84 identifies a corresponding hydraulic pump that is connected to the valve 82 via a connection line 86. The valve may be controlled here in such a way that it could pas a hydraulic medium both into the space section 96 and into the space section (or the hydraulic chamber) 94. It would also be conceivable here for the hydraulic drive unit 90 described here to have to be connected to the piston unit 43 only by means of a rod, and in this way intensively contaminated components would have no direct connection. Reference numeral 85 identifies a connection line.

[0098] As a hydraulic pump, the most varied pump types from the prior art may be considered. In addition, also the coupling device 95 between the piston rod 98 and the filling piston rod 69 may effect a real separation of the components.

[0099] Preferably, therefore, the apparatus has a coupling device that couples at least one element of the drive unit with at least the piston unit.

[0100] By means of the prestressing unit described here, which may also be achieved by means of the embodiment shown in FIG. 7 or the variant thereof, several objects are achieved. In this way, the costs of the drive unit are reduced compared to the case of a corresponding larger drive without a prestressing unit. Also, the use of a pressure connection could theoretically be eliminated.

[0101] The use of a hydraulic drive unit has the advantage that it usually has smaller dimensions. Apart from that, shorter switching times may often be realised, and it would be possible to partially use components known from the prior art or prefabricated components.

[0102] The applicant reserves the right to claim all of the features disclosed in the application documents as being essential to the invention, in as far as they are novel over the prior art either individually or in combination. It is further pointed out that features were described in the individual figures, which taken by themselves may be advantageous. A person skilled in the art will immediately recognise that a certain feature described in a figure may also be advantageous without adopting further features from this figure. A person skilled in the art will further recognise that advantages may be achieved also by combining several features shown individually or in various figures.

LIST OF REFERENCE NUMERALS

[0103] 1 Apparatus

[0104] 2 Forming station

[0105] 4 Pressure generation device

[0106] 6 Drive unit

[0107] 7 Prestressing unit, loading unit

[0108] 10 Plastic containers

[0109] 10a Mouth

[0110] 11 Expansion mould

[0111] 12 Rotatable carrier

[0112] 15 Supply device

[0113] 17 Discharge device

[0114] 22 Stretching rod

[0115] 24 Closure device

[0116] 25 Application device

[0117] 26 Filling housing

[0118] 27 Drive unit

[0119] 32 Pressure measuring device

[0120] 35 Connection line

[0121] 42, 44 Pressure generation unit

[0122] 43 Piston unit

[0123] 43a, b Pressure generation unit

[0124] 45 Reception space

[0125] 47 Liquid to be filled in

[0126] 50 Lever unit

[0127] 62 Drive unit

[0128] 63 Servomotor

[0129] 64 Output shaft

[0130] 65 Transmission unit

[0131] 66 Output shaft

[0132] 67 Linear spindle

[0133] 68 Rod element

[0134] 69 Rod element

[0135] 69 Filling piston rod

[0136] 72 Reservoir

[0137] 74 Connection line

[0138] 76 Valve

[0139] 78 Chamber

[0140] 82 Valve

[0141] 84 Hydraulic pump

[0142] 85 Connection line

[0143] 86 Connection line

[0144] 90 Hydraulic drive unit

[0145] 92 Piston element

[0146] 94 Hydraulic chamber, chamber section

[0147] 95 Coupling device

[0148] 96 Chamber section

[0149] 98 Piston rod

[0150] x Direction