APPARATUS AND METHOD FOR EXPANDING AND SIMULTANEOUSLY FILLING CONTAINERS

Abstract

Provided is an apparatus for expanding plastics material parisons into plastics material containers by a liquid medium having at least one transforming station, which fills and expands the plastics material parisons with the liquid medium with at least one delivery device, which delivers the liquid medium to a filling device of this transforming station, wherein this filling device is suitable and intended to fill the liquid medium into the plastics material parisons, and wherein the apparatus has a pressure generating device which delivers the liquid medium under pressure to the filling device. According to embodiments of the invention the pressure generating device has at least two pressure generating units which are suitable and intended to provide the liquid medium under pressure to the filling device.

Claims

1. An apparatus for expanding plastics material parisons into plastics material containers by a liquid medium having at least one transforming station, which fills and expands the plastics material parisons with the liquid medium with at least one delivery device, which delivers the liquid medium to a filling device of this transforming station, wherein this filling device is suitable and intended to fill the liquid medium into the plastics material parisons, and wherein the apparatus has a pressure generating device which delivers the liquid medium under pressure to the filling device, wherein the pressure generating device has a pretensioning device which pretensions at least one element of the pressure generating device.

2. The apparatus according to claim 1, wherein the pressure generating device has a receiving chamber for the liquid medium as well as a piston device which is movable relative to this receiving chamber in order to force the liquid medium to the filling device by a piston movement.

3. The apparatus according to claim 2, wherein the pretensioning device acts indirectly on the piston device and forces this in a predetermined direction.

4. The apparatus according to claim 1, wherein the pretensioning device pretensions the element of the pressure generating device in a translational direction.

5. The apparatus according to claim 1, wherein the pretensioning device has a pretensioning element, which is selected from a group of pretensioning elements which includes mechanical springs, permanent magnet springs, pneumatic springs, hydraulic elements, linear motor-powered elements, combinations thereof.

6. The apparatus according to claim 1, wherein in the interior of a receiving chamber for the liquid medium the pretensioning device generates a pressure which is at least one of greater than 2 bar, greater than 4 bar, greater than 6 bar and/or that in the interior of a receiving chamber for the liquid medium the pretensioning device generates a pressure which is at least one of less than 40 bar, less than 30 bar and less than 20 bar.

7. The apparatus according to claim 1, wherein the pretensioning can be changed and/or switched off.

8. The apparatus according to claim 1, wherein the pressure generating device has a driving device and this driving device has a spindle device.

9. The apparatus according to claim 1, wherein the pressure generating device has a toggle lever.

10. A method for expanding plastics material parisons into plastics material containers by a liquid medium, with at least one transforming station, which fills and expands the plastics material parisons with the liquid medium, wherein with at least one delivery device the liquid medium is delivered to a filling device of the transforming station, wherein the filling device fills the liquid medium into the plastics material parisons, and wherein a pressure generating device delivers the liquid medium under pressure to the filling device, characterised in that at least one element of the pressure generating device is pretensioned at least intermittently by a pretensioning device.

Description

BRIEF DESCRIPTION

[0078] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0079] FIG. 1 shows a rough schematic representation of an apparatus;

[0080] FIG. 2 shows a representation of a transforming station according to the internal known art of the applicant;

[0081] FIG. 3 shows a representation of a transforming station;

[0082] FIG. 4 shows a further representation of a transforming station;

[0083] FIG. 5 shows a representation of a pressure generating device with a toggle lever;

[0084] FIG. 6 shows a representation of a transforming station with a pretensioning device; and

[0085] FIG. 7 shows a representation of a transforming device with a hydraulic or pneumatic driving device.

DETAILED DESCRIPTION

[0086] FIG. 1 shows a schematic representation of a machine according to embodiments of the invention for transforming and filling containers. This has a rotatable carrier 12 on which a plurality of transforming/filling devices are arranged. As mentioned above, these transforming devices serve to fill and to expand the plastics material parisons simultaneously with a container. By means of a delivery device 15, such as for instance a delivery star, plastics material parisons are delivered to the apparatus and the finished and filled containers are then transported away from the apparatus by means of a discharge unit 17.

[0087] FIG. 2 shows a transforming station 2 according to the internal known art of the applicant. In this case the actual filling device is provided here, which has an application device 25 which can be placed onto a mouth 10a of the plastics material parisons to be expanded, in order thus to fill and to shape the plastics material containers 10. For this purpose, the transforming device has an expansion mould 11, inside which the plastics material parisons are expanded to form the plastics material bottles or plastics material containers. The reference numeral 26 designates a filling housing, inside which a closure device 24, such as for instance a closure stopper, is arranged. The delivery of liquid into the container 10 can be regulated by a movement of this valve body in the longitudinal direction L of the container.

[0088] The reference numeral 22 designates a so-called stretching rod which can be introduced into the interior of the containers, in order also to stretch them in their longitudinal direction. For this purpose, the apparatus has a driving device 27 which is suitable and intended for moving the stretching rod in its longitudinal direction.

[0089] The reference numeral 4 designates the pressure generating device as a whole which delivers the liquid under pressure to the plastics material container. Here this pressure generating device only has one pressure generating unit. In this case the pressure generating device, more precisely the pressure generating unit, has a receiving chamber 45, inside which the liquid 47 to be filled is provided. In addition, feed conduits can also be provided which deliver the liquid to the receiving chamber 45 (for instance from a reservoir which is not shown).

[0090] The reference numeral 43 designates a piston device which is movable in the direction x, in order thus to transport the liquid by means of a connecting conduit 35 to the actual filling head (also designated above as a filling device). The reference numeral 62 designates the driving device in particular in the form of a servomotor 63 which drives the movement of the piston device 43. For this purpose, the driving device generates a rotary movement which is output by means of an output shaft 64. The reference numeral 65 designates a transmission device, such as in this case a planetary gear transmission, and the reference numeral 66 designates a further output shaft. This output shaft in turn drives a linear spindle 67 and this moves rod elements 68 and 69, which are connected by means of a coupling and on which in turn the piston device is arranged.

[0091] Therefore, in the embodiment illustrated in FIG. 2 the apparatus merely has one single pressure generating device, which must supply the pressure for filling and expanding the containers. The reference numeral 32 designates a pressure measuring device which measures a pressure occurring in the filling housing 26.

[0092] FIG. 3 shows an embodiment of an apparatus or transforming station 2 according to embodiments of the invention. Here the actual filling head is structured in a similar manner to the embodiment shown in FIG. 2, and therefore is not explained in greater detail. Here, however, in contrast to the embodiment shown in FIG. 2, two pressure application units 42 and 44 are provided. These can be constructed in a similar manner and have already been described above, so that the description is not repeated. In this case it is possible that these pressure application units operate concurrently, but they can also fill the containers with a liquid medium in a staggered manner. In addition, it would also be possible that these two pressure application units 42 and 44 receive different liquids in their respective receiving spaces 47 and so for example a mixed product can be delivered to the container 10.

[0093] FIG. 4 shows an embodiment in which the total of four pressure application units 42 to 44 are provided, which likewise again are connected by means of connecting conduits to the actual filling device. In this case these four pressure generating units can contain several different products, for example four different products. In this case it would be possible that in turn the driving force is minimised and a product mixture is filled. In this case it is possible that in each of these pressure generating devices a product is provided which, either simultaneously or successively, is pressed by means of the actual filling device into the plastics material parisons to be transformed. In this case the necessary drive power for one of these four pressure generating units could be substantially reduced relative to the power required when only one single pressure generating unit is used.

[0094] In addition to or instead of the driving devices described above, however, hydraulic driving devices could also be provided, or also motors with a nut integrated in the rotor and a spindle, which is designed for example as a hollow shaft.

[0095] FIG. 5 shows a further embodiment of embodiments of the present invention. In this embodiment likewise two pressure generating units 42 and 44 are provided, wherein, however, the actual filling devices are not illustrated here. In this embodiment only one drive of the type designated above is provided, but in addition there is a lever device 50 which transmits the forces thus generated onto the piston devices 43. This lever device is configured here as a so-called toggle lever which is articulated on both piston devices 43 in order to move them. Thus, in this case the required forces are supplied by a toggle lever. The pressure profile during shaping of the containers necessitates a fast moulding process and, in the case of almost moulded bottles, a short path distance and high retaining forces.

[0096] FIG. 6 shows a further embodiment of embodiments of the present invention. In this embodiment the actual filling device has a similar structure to the above-mentioned filling device. The driving device 62-69 also has a similar structure to that mentioned above and therefore is not described further. In addition, however, the machine illustrated in FIG. 6 has a pretensioning device or a pre-loading device 7, which pretensions the piston device 43 downwards in the direction x. In the embodiment shown here this pretensioning device has a reservoir 72 in which for example air can be stored at a specific pressure. This air can be fed into the chamber 78 via a connecting conduit 74 and a valve 76. In this receiving chamber the pressurised air can additionally load the piston device 43 so that it is forced downwards.

[0097] Thus, in the embodiment shown in FIG. 6 the contact surface or the contact area for the pretensioning device is the rear side of the piston device 43.

[0098] FIG. 7 shows a further embodiment of the apparatus according to embodiments of the invention. In this embodiment the actual filling device is also formed in the manner shown above. Here too there is a receiving chamber 47 and a piston device which is movable relative to this receiving chamber. The embodiment shown in FIG. 7 differs in the type of drive for the piston device. A hydraulic or pneumatic driving device is used here as the driving device. For this purpose, here too a hydraulic chamber 94 is also provided, relative to which a piston element 92 is likewise movable in the direction x. The reference numeral 98 designates a piston rod which in turn is coupled to the piston device 43 by means of a coupling device.

[0099] The reference numeral 82 designates a valve which is switchably controlled. A time-controlled volume adjustment could be performed by precise switching of this valve 82. In addition, inside this driving device 90 mechanical stops or a changed volume flow of a pump would also be conceivable. The reference numeral 84 designates a corresponding hydraulic pump which is connected by means of a connecting conduit 86 to the valve 82. In this case the valve can be controlled in such a way that it can convey a hydraulic medium both into the chamber portion 96 and into the chamber portion (or hydraulic chamber) 94. In this case it is also conceivable that the hydraulic drive unit 90 described here would have to be connected only by a rod to the piston device 43 and in this way components which are pollution-intensive have no direct connection. The reference numeral 85 designates a connecting conduit.

[0100] The most varied types of pumps from the known art can be considered as a hydraulic pump. In addition, the coupling device 95 can also produce a real separation of the components between the piston rod 98 and the filling piston rod 69.

[0101] Therefore, the apparatus generally has a coupling device which couples at least one element of the drive unit to at least the piston device.

[0102] Several objects are achieved by the pretensioning described here, which can also be achieved by the embodiment shown in FIG. 7 or by the variant. In this way the driving device is more favourable than a corresponding larger drive without pretensioning. Theoretically a pressure connection can also be dispensed with.

[0103] The use of a hydraulic drive unit has the advantages that it usually has smaller dimensions. In addition, faster switching times can also often be implemented, and components which are in part known from the known art or are prefabricated can be used.

[0104] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0105] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements. The mention of a unit or a module does not preclude the use of more than one unit or module.

LIST OF REFERENCES

[0106] 1 apparatus [0107] 2 transforming station [0108] 4 pressure generating device [0109] 6 driving device [0110] 7 pretensioning device, loading device [0111] 10 plastics material containers [0112] 10a mouth [0113] 11 expansion mould [0114] 12 rotatable carrier [0115] 15 delivery device [0116] 17 discharge device [0117] 22 stretching rod [0118] 24 closure device [0119] 25 application device [0120] 26 filling housing [0121] 27 driving device [0122] 32 pressure measuring device [0123] 35 connecting conduit [0124] 42, 44 pressure generating unit [0125] 43 piston device [0126] 43a,b pressure generating unit [0127] 45 receiving chamber [0128] 47 liquid to be filled [0129] 50 lever device [0130] 62 driving device [0131] 63 servomotor [0132] 64 output shaft [0133] 65 transmission device [0134] 66 output shaft [0135] 67 linear spindle [0136] 68 rod element [0137] 69 rod element [0138] 69 filling piston rod [0139] 72 reservoir [0140] 74 connecting conduit [0141] 76 valve [0142] 78 chamber [0143] 82 valve [0144] 84 hydraulic pump [0145] 85 connecting conduit [0146] 86 connecting conduit [0147] 90 hydraulic drive unit [0148] 92 piston element [0149] 94 hydraulic chamber, chamber portion [0150] 95 coupling device [0151] 96 chamber portion [0152] 98 piston rod [0153] x direction