This application claims priority to Italian Patent Application no. 102021000032888 filed on Dec. 29, 2021, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a handling unit for moving a mold closing element of a forming machine for producing hollow glass articles.
As is known, forming machines, universally known as IS machines, are used to form hollow glass articles.
Such machines comprise a plurality of forming sections arranged side by side, into each of which a succession of drops of glass enters and from each of which a succession of formed hollow glass articles exits.
Each molding section comprises a blank mold and a finishing mold arranged downstream of the blank mold. Both molds can have a single forming cavity or a plurality of forming cavities arranged next to one another.
Regardless of the number, each forming cavity is open in an upward direction and must be closed fluid-tight at the top during the forming phase of the glass article.
Each cavity is accordingly provided with a related closing element which extends vertically and closes the related cavity completely in the case of blank molds, or partially in the case of finishing molds, thus allowing a flow of compressed forming air to be introduced into the finishing molds from above.
The closing elements of a same mold are carried by a dedicated supporting head, which is connected to a free end of an arm. The arm extends in a cantilever manner from a motorized vertical drive shaft, and is coupled to said shaft by means of a respective attachment clamp fixed to the column by means of clamping screws.
The vertical shaft and, together with the latter, the related arm are vertically movable in order to move the related closing elements between a raised resting position and a lowered operating position, in which the related closing elements are coupled to the respective mold in a fluid-tight manner.
As is known, IS machines are set up to be provided with different molds depending on the article to be produced. These molds have different dimensions and, in particular, different heights.
Therefore, at each mold change, the height position of the closing elements must be adjusted according to the height of the mold that will be mounted on the machine and so that the closing elements are always coupled tightly to the mold when arranged in their lowered operating position.
Adjustment is currently carried out manually by a team of responsible operators, who, at each mold change, demount the closing elements and mount the respective setting templates, known in the jargon as “callipers” or “face mold”, in their stead.
Each face mold is dimensioned so as to couple with the mold on the machine in exactly the same way as the related closing element and has a height that is less than the height of the related closing element so as to take into account the inevitable deformations of the handling unit under working conditions.
The use of face molds is rendered necessary and indispensable by the fact that the closing elements end, at the bottom, in sharp edges that would be damaged during the manual adjustment in the event of an accidental contact or collision of the closing elements with the new mold, and in any case if they are not arranged exactly in the intended correct operating position.
Once the face molds are mounted, still manually, the clamping screws of the clamp are loosened under the control of one of the responsible operators and the arm and the related head lowered or raised until the face molds are coupled to and in abutment with the related mold underneath.
Once this position has been reached, which is assumed as the new reference height position, the clamp is, still manually, tightened again on the vertical shaft, effectively rendering the arm integral with said vertical shaft, after which the face molds are demounted and, in their stead, the closing elements dedicated to the new mold are mounted on the machine.
As mentioned above, the foregoing steps are repeated manually at each mold change and for both molds in each of the forming sections.
Although universally implemented, the above-described manner of setting the closing elements is hardly satisfactory for the following reasons.
First of all, it is immediately obvious how this makes it necessary, for each mold that can be mounted on the machine, to have on hand a plurality (one for each mold cavity) of face molds, with imaginable costs both in terms of the manufacture as well as the storage and handling of said face molds.
Moreover, the setting of the closing elements of the entire forming machine requires, at each mold change, extremely large amounts of time which increase with the number of sections due to the aforementioned mounting, demounting and remounting operations, with inevitable losses in terms of production.
As mentioned above, the foregoing operations require, for each mold in the section, at least a pair of responsible operators. This is because at least one of the operators has to support the arm-head assembly while the other operator loosens the clamping screws of the clamp and both accompany the arm and related head during the vertical repositioning. The loosening of the screws, the accompanying of the head and the correct positioning and coupling of the face molds to the related mold are operations that require experience and considerable coordination between the operators inasmuch as they must be conducted so as to avoid a jamming of the clamp on the shaft due to the fact that the arm and the head protrude in a cantilever manner from the vertical shaft.
The foregoing operations are also rendered difficult by the fact that the operators are forced to work while standing above the base of the machine and straddling the related molds and thus in awkward and dangerous working conditions.
In all cases, a significant and prolonged physical effort is required of the operators and, in general, the aforementioned operations inevitably involve a very long downtime of the machine.
The aim of the present disclosure is to provide a handling unit for moving a mold closing element of a forming machine that allows the problems set out above to be solved in a simple and cost-effective manner.
A particular aim of the present disclosure is to provide a handling unit that allows an adjustment of the closing elements to be carried out quickly, extremely safely and precisely while eliminating operator discretion.
A further aim of the present disclosure is to provide a handling unit that allows drastically reducing or at least simplifying manual operations, reducing or eliminating the physical effort required of operators, as well as reducing the number of operators responsible for such adjustments so as to minimize operating costs and machine downtime.
A last aim of the present disclosure is to provide a handling unit which is simple and cost-effective to produce, compact and which can be inspected and operated from the outside.
According to the present disclosure, a handling unit for moving at least one mold closing element in a machine for forming glass articles is provided, as defined in the appended claims.
The disclosure will now be described with reference to the accompanying drawings, which illustrate a non-limiting embodiment thereof, wherein:
In
The machine 1 comprises a plurality of forming sections 2, only one of which is visible in the attached figures.
Each forming section 2 comprises a blank mold 3 comprising, in this specific case, four forming cavities 4 arranged side by side and open in an upward direction and a finishing mold 5 also comprising four finishing cavities 6 open in an upward direction.
According to variants not illustrated, the molds 3 and 4 comprise a different number of cavities 4,6.
Regardless of the number of cavities 4,6, the machine 1 further comprises a closing assembly 8 for closing the cavities 4 of the blank mold 3 and a closing assembly 9 for closing the cavities 6 of the finishing mold 5 and configured to allow compressed air to be introduced into said cavities 6.
With reference to
Each closing element 11 is coupled to the head 10 in a manner known per se, protrudes vertically downwards and is configured to couple with the mold 3 in order to completely close the related cavity 4.
Each assembly 8 further includes a handling unit 13 for moving the head 10 and the related closing elements 11.
The unit 13 comprises a dedicated attachment frame 14 fixed to a structure 15 of the machine 1 in proximity of the blank mold 3 (
The unit 13 further comprises a related drive shaft 16, which has a vertical axis 18, a straight upper end section 19 projecting upwards beyond the frame 14 and a lower end section (not visible in the attached figures) coupled to a drive device K, known per se and not described in detail, for moving the shaft 16 with a roto-translatory motion along the axis 18.
The unit 13 finally comprises a slide 20 coupled to the section 19 so as to be slidable along the axis 18 in opposite directions, and an arm 21 that supports the head 10 and extends orthogonally to the axis 18.
Preferably, the slide 20 can be locked manually from the outside by means of a dedicated wrench acting, for example, on a screw 20A.
Alternatively, the slide 20 is locked on the section 19 by means of a motorized locking device, e.g., of a mechanical friction or magnetic type and in any event a device that can be controlled from outside the machine or remotely.
The arm 21 comprises a free end portion 22 firmly connected to the head 10 and an attachment end portion 23, opposite the portion 22 and coupled to the slide 20 by means of a releasable coupling 24 for the quick replacement of the arm-supporting head assembly.
Conveniently, the coupling 24 comprises a vertical guide 25 parallel to the axis 18 and firmly connected to the slide 20, and a slide 26 firmly connected to the attachment portion 23 and couplable from above to the guide 25. The slide 26 is clamped on the guide 25 in a releasable manner by means of a clamping screw 27, which can be actuated manually from the outside by means of a dedicated wrench. Alternatively, the slide 26 is locked on the guide 25 by means of a motorized locking device, e.g., of a mechanical friction or magnetic type and in any event a device that can be controlled from outside the machine or remotely.
With reference to
The transmission 30 comprises a screw 31 arranged outside the section 19 of the vertical shaft 16 and coupled to the vertical shaft 16 in a rotatable manner about its axis 31A and in an axially fixed position, and a nut screw 32 engaged by the screw 31 and coupled to the slide 20 in a vertically and angularly fixed position with respect to said slide 20.
Again with reference to
Conveniently, the motor 35 extends upwards from the attachment portion 38, to which it is firmly attached.
Still with reference to
The unit 40 comprises a memory block 40A storing, for each mold 3,5 that is installable on the machine 1, a respective reference position of the closing elements 11, i.e. their correct height position, and a command and control block 40B for controlling the motor 35 and moving the closing elements 11 into the reference or operating positions depending on the mold currently mounted on the machine 1.
Conveniently, each unit 40 communicates with a general machine unit 41 that synchronizes the position adjustment activities of all relevant closing elements 11 by controlling all of said closing assemblies in response to a mold change program.
Again with reference to
The closing elements 45, also known per se, differ from the elements 11 in that they couple to each cavity 6 fluid-tightly and respectively define a respective compressed air supply duct within the related cavities 6. The head 43 further differs from the head 10 in that it carries ducts 45A for supplying compressed air to the respective closing elements 45.
In the variant illustrated in
It is evident from the foregoing that the use of a slidable slide along the section 19 of the vertical shaft 16 and the presence of the transmission 30 allow a single operator responsible for the section 2 to correctly position the closing elements 11,45 at each mold change in an extremely short period of time, simply by acting from the outside on the shaft 46 by means of a common crank or manoeuvring wrench or by controlling the motors 35 via the units 40, and without the need to intervene on the device K that drives the shaft 16.
In any case, the precision and continuity with which the arms 21, and with them the related heads 10,43, are moved, allow a single operator to carry out the height adjustment at a mold change without the need to demount and remount the closing elements 11,45 from the related heads 10,43 and, above all, compared to known solutions, to be able to adjust the height of the closing elements 11 and 45 without having to use “face molds”, which can consequently be completely eliminated, thus fundamentally solving all the problems linked with the handling and storage of the same.
In particular, during the adjustment performed by the transmission 30, the arms 21 only move with a translatory motion, i.e. they translate while remaining parallel to themselves, so that the spatial orientation of the closing elements 11,45 is not altered.
Using the 35 motors also practically eliminates the physical effort required of operators inasmuch as they can operate remotely on the individual section 2 or simultaneously on the entire machine in response to an issued mold change command.
Compared to known solutions, the physical effort is reduced even without the motors 35 inasmuch as the adjustment is limited to the mere rotation of a crank or wrench couplable to the shafts 46 that protrude at the front and thus in an area easily accessible from the outside and without the need to climb up onto or down from the surface supporting the molds, i.e. while remaining outside the forming section, with considerable advantages in terms of safety.
Again compared to known solutions, the presence of the drive motors 35 and the presence of the related command and control units eliminate the arbitrariness of the movement as there is a transition from little more than a visual control on the part of the operator to a fully automatic control of the individual section 2 or of the entire machine 1 on the basis of information stored in memories or databases, for example in said command and control unit.
The presence of the motors 35 and the screw-nut screw transmission 30 facilitates an extremely precise and gradual positioning of the closing elements 11,45, thus preventing any damage to said closing elements during the mold change phase.
It is also evident from the foregoing that the provided handling units 13 are simple in design, cost-effective and, above all, extremely compact as well as being immediately inspectable from the outside.
The compactness and simplicity of the design also allow the described closing assemblies 8,9 to be used on existing forming machines without requiring any particular modifications or adaptations of said machines.
It is evident from the foregoing that the described closing assemblies 8,9 can be modified and varied without departing from the scope of protection defined by the independent claims as a result.
In particular, the arms 21 and heads 10,43 can have different shapes and geometries from those indicated, for example in order to support a different number of closing elements.
In addition, the transmissions 30 could be provided with both motors 35 and transmissions 47 so as to be capable of manual operation in any operating condition including failures of the electrical control.
Number | Date | Country | Kind |
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102021000032888 | Dec 2021 | IT | national |