GLASS FORMING METHOD WITH INDIVIDUALLY CONTROLLED PLUNGER END POSITIONS

Abstract

A glass forming machine and a method for manufacturing formed glass parisons. A glass forming machine includes a blank side for forming parisons from gobs of molten glass. The blank side includes a plunger and a blank mould. The plunger can be moved into the blank mould up to an end position. The plunger can be moved out of the blank mould up to a start position. The glass forming machine includes a glass feeding device which is configured to bring a gob of molten glass into the blank mould. The glass forming machine includes a measuring device which is configured to measure the end position of the plunger. The glass feeding device is configured such that the size of a gob of molten glass depends on the end position previously reached during operation. Parisons of good quality can be produced with a bigger tolerance of mould volumina.

Claims

1. Method for manufacturing formed glass parisons, comprising: performing a first cycle using a blank side having a plunger and a blank mould, the first cycle comprising the steps: i. bringing a first gob of molten glass into the blank mould by means of a glass feeding device, ii. moving the plunger up to an end position such that a first parison is formed from the first gob of molten glass, iii. measuring the end position of the plunger by means of a measuring device, and iv. removing the parison from the blank mould, performing a second cycle using the blank side, the second cycle comprising the steps: i. adjusting the glass feeding device in response to the measured end position of the plunger such that a size of a second gob of molten glass is set in response to the measured end position of the plunger, ii. bringing a second gob of molten glass with the set size into the blank mould by means of the glass feeding device, iii. moving the plunger up to an end position such that a second parison is formed from the second gob of molten glass, and iv. removing the parison from the blank mould.

2. Method according to claim 1, wherein adjusting the glass feeding device comprises moving a needle of the glass feeding device with respect to a discharge orifice of the glass feeding device by an electrical motor previously to and/or during bringing the second gob of molten glass into the blank mould.

3. Method according to claim 2, wherein the movement of the needle is controlled by means of a control device based on an information associated with a position of the needle detected by a sensor.

4. Method according to claim 1, wherein the size of the second gob is smaller or larger than the size of the first gob.

5. Method according to claim 1, wherein the method is performed using a glass forming machine which includes a blank side for forming parisons from gobs of molten glass; the blank side includes a plunger and a blank mould; the plunger can be moved into the blank mould up to an end position; the plunger can be moved out of the blank mould up to a start position; the glass forming machine includes a glass feeding device which is configured to bring a gob of molten glass into the blank mould; the glass forming machine includes a measuring device which is configured to measure the end position of the plunger.

6. Method according to claim 1, wherein the glass feeding device comprises: a feeder bowl adapted for containing molten glass, said feeder bowl having a discharge orifice, a movable needle, an electrical motor adapted to move the needle with respect to the discharge orifice, a control device being configured to control the movement of the needle, a sensor for detecting an information associated with a position of the needle in order to control the movement of the needle, and a shear mechanism which is configured to divide a stream of molten glass emerging from the discharge opening into gobs of molten glass.

7. Method according to claim 6, wherein the control device controls the movement of the needle such that the size of a gob of molten glass depends on the measured end position.

8. Method according to claim 6, wherein the diameter of the stream is increased and decreased in an oscillating and/or wave-like manner.

9. Method according to claim 1, comprising: receiving, by one of an input device and by an interface, an end position range, storing said end position range in a memory, comparing if the measured end position is within the end position range, if the measured end position is not within the stored end position range, adjusting the glass feeding device such that the size of the second gob of molten glass is within the end position range.

10. Method according to claim 9, wherein the range is less than 8 mm.

11. Method according to claim 9, comprising: storing said end position range for a plurality of cycles, and calculating a trend based upon end positions of a plurality of previous cycles, improving control of the glass feeding device based on the trend.

12. Method for manufacturing formed glass parisons, comprising: forming a first parison from a first gob of molten glass by means of a blank side having a plunger and a blank mould, including bringing the first gob of molten glass into the blank mould by means of a glass feeding device and moving the plunger up to the end position, measuring the end position of the plunger by means of a measuring device, forming a second parison from a second gob of molten glass by means of the blank side, including bringing the second gob of molten glass into the blank mould by means of the glass feeding device and moving the plunger up to the end position, such that the size of the second gob of molten glass depends on the measured end position.

13. Method according to claim 12, wherein a needle of the glass feeding device is moved with respect to the discharge orifice by an electrical motor previously to and/or during bringing the second gob of molten glass into the blank mould such that the size of the second gob of molten glass depends on the measured end position.

14. Method according to claim 13, wherein the movement of the needle is controlled by means of a control device based on an information associated with a position of the needle detected by a sensor.

15. Method according to claim 12, wherein in a plurality of blank sides a plurality of first parisons are formed from a plurality of first gobs of molten glass and subsequently, in said plurality of blank sides, a plurality of second parisons are formed from a plurality of second gobs of molten glass such that the size of each of the second gobs of molten glass depends on the previously measured end position of the plunger of the respective blank side during formation of the first gobs of molten glass.

16. Method according to claim 12, wherein the glass feeding device is influenced by the measured end position of the plunger such that the size of the second gob of molten glass depends on the end position.

17. Method according to claim 12, wherein the size of the second gob is smaller or larger than the size of the first gob.

18. Method according to claim 12, wherein the glass feeding device comprises: a feeder bowl adapted for containing molten glass, said feeder bowl having a discharge orifice, a movable needle, an electrical motor adapted to move the needle with respect to the discharge orifice, a control device being configured to control the movement of the needle, a sensor for detecting an information associated with a position of the needle in order to control the movement of the needle, and a shear mechanism which is configured to divide a stream of molten glass emerging from the discharge opening into gobs of molten glass.

19. Method according to claim 18, wherein the control device controls the movement of the needle such that the size of a gob of molten glass depends on the measured end position.

20. Method according to claim 12, wherein the end position of the plunger is kept within a predefined range, wherein the predefined range is a range of less than 12 mm.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0054] The invention is further illustrated with the aid of the following examples, with reference to the appended drawings in which:

[0055] FIG. 1 is a schematic representation of a blank side at the beginning of the production of a parison;

[0056] FIG. 2 is a schematic representation of the blank side during the production of a parison;

[0057] FIG. 3 is a schematic representation of the blank side at the end of the production of a parison;

[0058] FIG. 4 is a schematic representation of an invert mechanism at the beginning of a transfer of the parison;

[0059] FIG. 5 is a schematic representation of the invert mechanism at the end of a transfer of the parison;

[0060] FIG. 6 is a schematic representation of a blow station at the beginning of the production of a glass bottle;

[0061] FIG. 7 is a schematic representation of the blow station at the end of the production of the glass bottle;

[0062] FIG. 8 is a schematic representation of the glass bottle:

[0063] FIG. 9 is a schematic representation of a glass feeding device and a plurality of blank moulds; and

[0064] FIG. 10 is a schematic representation of another configuration of the glass feeding device.

DETAILED DESCRIPTION OF THE INVENTION

[0065] The FIGS. 1 to 8 illustrate the production of a glass bottle. FIGS. 9 and 10 relate to the glass feeding device and to details of the method according to the invention.

[0066] FIG. 1 refers to a blank side of a glass forming machine. FIG. 1 shows one blank mould 1 of the blank side. The blank mould 1 consists of two blank mould halves 2 and 3. The blank mould halves 2 and 3 are in a closed position. The two blank mould halves 2 and 3 are closed up on a neck ring 5 at the lower end of the blank mould 1.

[0067] There is an annular recess 6 formed by the two halves 2, 3 when the two halves 2 and 3 are in their closed position. The neck ring 5 comprises an upper annular projection 7. The upper annular projection 7 extends into the annular recess 6 when the two halves 2, 3 are in their closed position. In the closed position of the two halves 2, 3, these are then fixed by positive locking with the neck ring 5.

[0068] The inner wall of the neck ring 5 can have a bulge 8. A parison can be held by this bulge 8, as shown in FIG. 3.

[0069] As shown in FIG. 1, a gob of molten glass 9 can be brought into the blank mould from above by means of a glass feeding device which is not shown here. This can be in particular assisted by gravity.

[0070] The blank side includes a plunger 10. According to FIG. 1, the plunger 10 is in a start position being a retracted position. The plunger 10 reaches through the neck ring 5. The plunger 10 tapers in the direction of the blank mould 1. When the plunger 10 is in the start position, the plunger 10 ends close to the bottom of the blank mould 1 as well as above the bottom of the blank mould 1 as shown in FIG. 1.

[0071] The blank mould 1 has an upper opening 11 on the upper side such that the glass feeding device can bring a gob of molten glass 9 into the blank mould 1.

[0072] The neck ring 5 can include a flange 12 on which the blank mould 1 can rest. Further, the neck ring 5 can include a lower annular projection 13 in order to be able to connect the neck ring 5 positively with an arm of an invert mechanism.

[0073] As soon as the gob of molten glass 9 is completely within the blank mould 1, the upper opening 11 of the blank mould 1 is closed by a baffle 33 as shown in FIG. 2. After the upper opening 11 has been closed, the plunger 10 is moved upwards, i.e. further into the blank mould 1, towards its end position or extended position. This upward movement of the plunger 10 is illustrated in FIGS. 2 and 3. The gob of molten glass 9 thus becomes a parison 14. The parison 14 is shown in FIG. 3. Here, the plunger is in its end position. Then, the cavity of the blank mould is completely filled with glass.

[0074] Once the parison 14 has been formed and in particular at least partly solidified, the blank mould 1 is opened. The baffle 33 and the two halves 2 and 3 of the blank mould 1 are removed from the parison 14. The parison 14 remains on the neck ring 5. Further, the parison 14 is held by the bulge 8 of the neck ring 5. For example, the baffle 33 is pulled out of the parison 14. After that the two halves will be moved away.

[0075] A gripper 15 of an invert mechanism 16 then grips for example the lower projection 13 of the neck ring 5 as illustrated in FIG. 4. The gripper 15 is attached to an L-shaped arm 17 of the invert mechanism 16. The L-shaped arm 17 can be rotated about one axis 18. The rotation is done by means of a motor. The motor is not shown in FIG. 4.

[0076] After the gripper 15 has gripped the neck ring 5, the L-shaped arm 17 is rotated 180° around the axis 18. FIG. 5 shows this rotated state. The parison 14 is thus brought to a base 19 of a blow station 20. The parison 14 is then located above this base 19.

[0077] The blow station 20 comprises a blow mould which consists of two blow mould halves 21 and 22. After the parison 14 has been brought to the base 19, the two halves 21 and 22 are moved towards the parison 14. Subsequently, the parison 14 is inside the blow mould 21, 22 as shown in FIG. 5.

[0078] When the parison 14 is inside the blow mould 21, 22, the neck ring 5 is removed. To do this without damaging the parison 14, the neck ring 5 also consists of two halves. The two halves of the neck ring 5 can therefore be removed from each other to remove the neck ring 5 from the parison 14 as illustrated in FIG. 6.

[0079] The two halves 21 and 22 consist of a double wall. A gap 23 remains between the two walls of the double wall. The inner wall of the double wall is perforated or otherwise air-permeable. The base 19 comprises ducts 24 through which air can be sucked out of each gap 23.

[0080] A blow head 25 is then placed on the two halves 21 and 22 of the blow mould. Air is then pumped through the blow head 25, inflating the parison into a bottle 26, as shown in FIG. 7. Inflating can be supported by sucking air through the ducts 24.

[0081] After the bottle 26 has been inflated, the blow head as well as the two halves 21 and 22 of the blow mould are removed. The bottle 26 can then be gripped by a take out 27 and placed on a conveyor belt 28, for example, as illustrated in FIG. 8.

[0082] FIG. 9 schematically shows a glass feeding device 60, also referred to as feeder, and a plurality of blank moulds 1. FIG. 9 also refers to the blank side. The glass feeding device comprises a feeder bowl 62 which contains molten glass 40. On the lower side it comprises two discharge orifices 61 to simultaneously discharge two streams 42 of molten glass 40. On the lower side of the feeder bowl 62, the discharge orifices are integrated into an orifice ring. On the left hand side, the feeder bowl 62 is connected to a furnace (not shown here) from which molten glass is guided to the discharge orifices 61 as indicated by arrows 41 and 42. Below the discharge orifices 61, the glass feeding device 60 comprises a shear mechanism (not shown here) for dividing the resulting streams 42 of molten glass 40 emerging from the feeder bowl 62 into separate gobs of molten glass 9 as schematically depicted. The shear mechanism may comprise a shear blade for cutting individual gobs.

[0083] Within the feeder bowl 62 there is a tube 43 made of ceramic material. By upward or downward movement of the tube 43, the streams 41 of molten glass 40 can be increased or decreased. This affects all streams 41 in the same way.

[0084] In order to control the size of the streams 42 emerging from the discharge orifices 61, the glass feeding device 60 comprises two needles 50 each of which is associated with one discharge orifice 61. Each of the needles 50 is individually movable with respect to the respective discharge orifice 61, as indicated by arrows 51 and 52. Each needle 50 can be moved upwards and downwards along its respective longitudinal direction. This movement individually influences the size of the respective stream 42 of molten glass emerging from the respective discharge orifice 61 and, thus, the size of the gob of molten glass 9.

[0085] Below the feeding device 60, a set of blank moulds 1 is schematically shown. The set shown here in exemplary fashion comprises two rows h, v, and ten sections S1, S2, . . . S10 in the form of columns, each section comprising two blank moulds and two associated plungers. The respective plungers are not shown here. The glass feeding device comprises two discharge orifices 61 and two movable needles 50. The feeder bowl 62 is adapted to provide molten glass 40.

[0086] During operation, the gobs of molten glass 9 emerging from the discharge orifice 61 shown on the right hand side are fed into blank moulds 1 located in the front row v and the gobs of molten glass 9 emerging from the discharge orifice 61 shown on the left hand side are brought into blank moulds 1 of the back row h. Channels can be provided to guide the gobs of molten glass 9 into the cavities of the blank moulds 1. Firstly, gobs of molten glass 9 are brought into the blank moulds 1 of the first section S1, as indicated by the dotted arrows. Subsequently, gobs of molten glass 9 are brought into the blank moulds 1 if the second section S2. This is repeated until all blank moulds 1 are filled with gobs of molten glass 9. The channels can be adjusted to achieve this.

[0087] After filling the blank moulds 1 of the first section S1, the size of the gobs of molten glass 9 can be influenced by moving the needles upwards or downwards for the next section. The glass feeding machine is configured such that the size of a gob of molten glass 9 depends on the end position previously reached during operation. To this end, a measuring device (not shown here) measures the end position of the plunger, e.g. of the blank moulds 1 of the first section S1, and the needles 50 are moved along arrows 51, 52. In doing so they are controlled such that the end position of the plunger previously reached during operation of the glass forming machine is used. This is in order to influence the size of the gobs of molten glass 9. The position of a needle 50 may be readjusted after each production cycle. Before producing a gob for a specific section, the position of a needle 50 may be readjusted after each production cycle.

[0088] In one configuration, the memory of the glass forming machine stores end positions measured in each blank mould 1 of the shown set of blank moulds 1 and after bringing gobs of molten glass 9 into each blank mould 1 of the set and after releasing the produced parisons from the blank moulds 1 and before bringing subsequent gobs of molten glass 9 into each of the blank moulds 1, the glass feeding device moves the needles 50 in order to influence the size of the subsequently produced gobs of molten glass 9 based upon the stored end positions of the respective plungers. In other words, the gob sizes can be controlled individually and continuously from cut to cut. Thus, cavities having different sizes, e.g. due to repeated reprocessing, can be utilized in an optimal manner. In particular, the glass feeding device is configured to detect and store a movement profile of the plunger. The shear mechanism may be configured to divide the streams 42 of molten glass 40 at an earlier or later point of time with respect to the movement of the needle 50.

[0089] A glass feeding device can also have more than two discharge orifices 61 and more than two needles 50. So there can also be three needles 50 and three discharge orifices 61 or four needles 50 and four discharge orifices 61 and so on.

[0090] FIG. 10 schematically shows another configuration of the glass feeding device 60 in a detailed manner. In contrast to the glass feeding device 60 shown in FIG. 9, it comprises three discharge orifices 61 and three needles 50 associated with the respective discharge orifices 61. Each needle is connected to an electrical motor 63, a sensor 65 and a control device 64. Each of the needles 50 is movable individually with respect to the respective discharge orifice 61, as indicated by arrows 51, 52 and 53. This is realized by means of the electrical motor 63 being controlled by the control device 64 which uses information regarding the position of the needle 50 detected by the sensor 65. Each group of electrical motor 63, control device 64 and sensor 50 is connected to a central power and/or control unit (not shown) by an electrical and/or data connection 66.

LIST OF REFERENCE SIGNS

[0091] blank mould 1 [0092] blank mould halves 2, 3 [0093] neck ring 5 [0094] annular recess 6 [0095] upper annular projection 7 [0096] bulge 8 [0097] gob of molten glass 9 [0098] plunger 10 [0099] upper opening 11 [0100] flange 12 [0101] lower annular projection 13 [0102] parison 14 [0103] gripper 15 [0104] invert mechanism 16 [0105] L-shaped arm 17 [0106] axis 18 [0107] base 19 [0108] blow station 20 [0109] blow mould halves 21, 22 [0110] gap 23 [0111] ducts 24 [0112] blow head 25 [0113] bottle 26 [0114] take out 27 [0115] conveyor belt 28 [0116] baffle 33 [0117] molten glass 40 [0118] arrow 41 [0119] stream 42 [0120] tube 43 [0121] needle 50 [0122] arrows 51, 52, 53 [0123] glass feeding device 60 [0124] discharge orifice 61 [0125] feeder bowl 62 [0126] electrical motor 63 [0127] control device 64 [0128] sensor 65 [0129] electrical and/or data connection 66 [0130] sections S1, S2, . . . S10 [0131] front row v [0132] back row h

[0133] The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and fall within the scope of the invention.