Apparatus and method for calibrating a thermoplastic spacer

Abstract

An apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass comprises translation and support means (30) adapted to translate at least one glass plate (2') along a direction (x), and lateral support means (35) adapted to sustain a glass plate (2') in a substantially vertical position. The apparatus further comprises at least one calibration device (10) adapted to modify the shape of a thermoplastic spacer arranged on a glass plate (2') and positioning means (36) adapted to position the calibration device (10) with respect to the plane defined by the lateral support (35) along the direction (x) and along a substantially vertical direction (y). The calibration device (10) comprises a calibration element (38' ) movable at least along the substantially vertical direction (y) between a lowered resting position and a raised operating position in which it is adapted to interact with the thermoplastic spacer (3) along the substantially vertical direction (y).

Description

APPARATUS AND METHOD FOR CALIBRATING A THERMOPLASTICSPACERDESCRIPTIONFIELD OF APPLICATION

[0001] The present invention relates to an apparatus and method for calibrating a thermoplastic spacer for insulating glass. In particular, the present invention relates to a device and a method for correcting the deformation due to the action of gravity on the thermoplastic spacer after the application on the glass and prior to the assembly with the subsequent glass plate.BACKGROUND ART

[0002] As is known, insulating glass in the simplest configuration thereof consists of two glass plates separated by a spacer which can be rigid, i.e., consisting of metal material, rigid polymer material or mixed metal-polymer material, or flexible supplied on coils, or finally made of thermoplastic material supplied in drums and extruded directly onto the glass through automated machines.

[0003] The present invention relates to the case of use of the thermoplastic spacer, for which its depositing onto a glass plate is known, and the subsequent coupling to another glass plate, to then seal the assembly on theentire outer periphery with a secondary sealant to form the so-called insulating glass.

[0004] It is known that a multiple operation can be involved to obtain, for example, an insulating glass consisting of three glass plates and two spacers, as well as "n" glass plates and "n-1" spacers.

[0005] In order to easily comprehend the disclosure below, it is useful a brief description of the solutions commonly implemented for applying, by means of automated machines, the thermoplastic material for making the insulating glass.

[0006] According to the indications of the manufacturers, the extrusion of the thermoplastic material must occur at a temperature close to 130°C.

[0007] Preferably, the section of the spacer profile, at the time of its extrusion onto the glass, is rectangular, and in order to ensure an adequate adhesion between the spacer and the glass, it is prescribed for the application to occur so that the dimension of the strip deposited onto the glass, in the direction perpendicular to the glass itself, be about 10% (up to 12%) greater than the final dimension desired, which height is achieved with the steps of assembling and pressing the insulating glass. Therefore, the section of the spacer in the final configuration takes the typical, slightlybulged shape of the sides not in contact with the glass, as shown in the diagrammatic and emphasized depiction in Figure 1A.

[0008] The features of the materials used for making the thermoplastic spacer and the need to perform the extrusion of such materials at specific temperatures to utilise the lesser viscosity thereof implies that there is a limit to the maximum size obtainable from the spacer in terms of distance between the two glasses of the end product. Remembering that the glass plate to which the strip of thermoplastic material is applied is placed in an almost vertical position, i.e., generally inclined by 6° with respect to the vertical, due to the force of gravity, the result is that the horizontal sections of the spacer just extruded are subject to deflect downwards given the tendency of said materials under high temperature conditions to creep. All this results in a maximum distance limit between the two insulating glass plates obtainable using thermoplastic spacers. Such a limit, stated by the manufacturers of the materials and the manufacturers of the insulating glass production lines, is around 20 mm, while the market often requires much greater measurements, up to even 32 mm, which to date are easily obtainable only with other types of spacers.

[0009] The so-called vertical sections, considering the most frequent production case of a rectangular-shaped insulating glass, are not obviously subject to such a problem, while those partially inclined with respect to the horizontal are so, although to a lesser extent then the merely horizontal segments, in the case of shapes other than the rectangular shape.

[0010] The problem disclosed above is introduced in US2022 / 0186551A1, where the suggested solution consists in applying two separate strips of thermoplastic material, each for each of the two glass plates forming the insulating glass, which are positioned facing each other in the assembly step using a specific conveyor rotating around a vertical axis. The next assembly and pressing station is also configured to have two facing operating planes positioned in a "V", each adapted to accommodate one of the two glass plates. The assembly and pressing operations occur by closing the "V" defined by the two planes of the machine, with a combined rotation and translation movement. With such a solution, it can be stated that thermoplastic spacer sizes of 32 mm can be achieved.

[0011] In any case, the drawbacks of the solution suggested by US2022 / 0186551A1 are:- the need to perform two separate applications of thethermoplastic spacer rather than only one, with an increase in the cycle time of the line or with the need to use two applicators which can work simultaneously, one for each plate;- the need to use much more complex and costly machines than conventional ones; and- the non-optimal results in terms of appearance due to the presence of the inevitable and apparent junction line between the two thermoplastic spacer strips after assembly and pressing.OVERVIEW OF THE INVENTION

[0012] Therefore, it is the object of the present invention to at least partially solve the drawbacks of the prior art.

[0013] It is a first task of the present invention to overcome the limits attributed to the prior art with an apparatus and method capable of allowing the extrusion of the thermoplastic spacer without the deformation thereof occurring due to the force of gravity prior to the assembly step.

[0014] At the same time, the goal is to not increase the cycle time of the insulating glass production line.

[0015] In such a context, the overall costs of the production line are to be curbed, avoiding the implementation of complicated and costly technicalsolutions.

[0016] Finally, the solution must ensure an appearance of the end product which is in line with the expectations and habits of the market.

[0017] Such needs are met, at least partially, by an apparatus for calibrating a thermoplastic spacer for insulating glass according to claim 1, and by a method for calibrating a thermoplastic spacer for insulating glass according to claim 15.DESCRIPTION OF THE DRAWINGS

[0018] Further features and advantages of the present invention will be more comprehensible from the following description of preferred, non-limiting embodiments thereof, in which:- Figure 1A diagrammatically shows the section of an insulating glass 1 close to the peripheral edge, highlighting the glass plates 2 and 2', the thermoplastic spacer 3, and the secondary sealant 4;- Figure 2A diagrammatically shows the section view of a thermoplastic spacer 3 extruded onto the glass plate 2', in the ideal geometrical shape thereof after application;- Figure 2B shows the same view as Figure 2A, but with the spacer which underwent the bending deformation due to the force of gravity in a horizontal segment;- Figure 3A diagrammatically shows a device forcalibrating the thermoplastic spacer 3, in a retracted position;- Figure 3B shows the device in Figure 3A in the approaching position to the thermoplastic spacer;- Figure 3C shows the calibration device in Figure 3A in the active position thereof;- Figure 3D shows the calibration device in Figure 3A in a further active configuration;- Figure 4A shows a different configuration of the calibration device for a thermoplastic spacer, in the retracted position thereof;- Figure 4B shows the device in Figure 4A in the approaching position to the thermoplastic spacer, after the movement along axis Z;- Figures 4C show the device in Figures 4A and 4B in the active position, after the movement along axis Y;- Figure 5A shows a further different configuration of the calibration device for a thermoplastic spacer, in the retracted position thereof;- Figure 5B shows the device in Figure 5A in the approaching position to the thermoplastic spacer;- Figure 5C shows the solution in Figure 5A, but with the device in the active position;- Figure 6A shows a device for calibrating the thermoplastic spacer 3 in a retracted position in thespecific case in which the segment of interest of the thermoplastic spacer is close to the lower edge of the glass plate 2', i.e., that used for moving the plate itself through translation means 30;- Figure 6B shows the same view as Figure 6A, but with the translation means 30 in a release position and the calibration device 10 in the active position;- Figure 7 diagrammatically shows a side view of an apparatus for calibrating a thermoplastic spacer according to a possible embodiment; and- Figure 8 diagrammatically shows a side view of an apparatus for calibrating a thermoplastic spacer according to an alternative embodiment.

[0019] The elements or parts of elements common to the embodiments described below will be indicated by the same reference numerals.DETAILED DESCRIPTION

[0020] Figure 1A shows the peripheral section of an insulating glass consisting of two glass plates 2 and 2', a thermoplastic spacer 3, and a secondary sealant 4. The entire following disclosure obviously also applies to the cases in which more than two glass plates and more than one spacer are employed to make insulating glasses with more than one chamber. This type of embodiments is not shown, however they are well known to those skilled inthe art.

[0021] Figure 7 shows an apparatus for calibrating a thermoplastic spacer for insulating glass which is indicated by reference numeral 200 as a whole.

[0022] The apparatus 200 for calibrating a thermoplastic spacer 3 for insulating glass comprises translation and support means 30 adapted to translate at least one glass plate 2' along a direction x, and lateral support means 35 adapted to sustain a glass plate 2rin a substantially vertical position.

[0023] The lateral support means are diagrammatically shown in Figures 7 and 8, and considering that the structures are known per se, are not further discussed in detail.

[0024] The apparatus further comprises at least one calibration device 10 adapted to modify the shape of a thermoplastic spacer arranged on a glass plate 2', and positioning means 36 adapted to position the calibration device 10 with respect to the plane defined by the lateral support 35 along direction x and along a substantially vertical direction y.

[0025] The calibration device 10 comprises a calibration element 38 movable at least along the substantially vertical direction (y) between a lowered resting position and a raised operating position in which it is adapted to interact with the thermoplastic spacer 3 along thesubstantially vertical direction y.

[0026] Advantageously, the apparatus can comprise two calibration devices 10, 10' adapted to act on opposite edges of a glass plate 2'.

[0027] In other words, the apparatus 200 for calibrating a thermoplastic spacer 3 for insulating glass is an apparatus for bringing the two faces of the thermoplastic spacer 3, which are not intended to come into contact with the glass during the step of assembling the insulating glass, back to a position substantially perpendicular to the glass. Such an operation is referred to as the calibration of the thermoplastic spacer herein, meant as the reshaping to the original and desired shape thereof (rectangular with the largest size substantially perpendicular to the glass), after it underwent the deformation described in the paragraphs above due to the action of the force of gravity.

[0028] According to a possible embodiment, the translation and support means 30 can comprise motorised rollers or a conveyor belt.

[0029] The movement means 20 of the glass plate can comprise a carriage with suction cups which, combined with the means 30, allows an accurate and controlled movement of the glass plate 2' along direction X and the accurate positioning thereof.

[0030] Advantageously, the apparatus can comprise a positioning device 40. The positioning device 40 is a member which comes into contact with the glass plate when it needs to be positioned accurately and it sends data to a control unit through a measuring instrument (for example, a linear potentiometer), and thus is capable of accurately knowing where the glass plate is. It is thus possible to synchronize the movement of the glass plate with the intervention of the calibration devices.

[0031] According to a possible embodiment, the positioning means 36 can comprise a vertical guide 14 on which the at least one calibration device 10 can translate.

[0032] The positioning means 36 can comprise at least one motorisation 15 and 15' for positioning the calibration device 10 at the desired height along the substantially vertical axis Y.

[0033] According to a possible embodiment shown in Figures 4A-4C, the calibration device 10 can comprise an actuator 11, 11' of the linear type for moving the calibration element 38, 38' along a direction z substantially perpendicular to the plane defined by the lateral support means 35.

[0034] In this case, the switching from the retracted position to the extracted (active) position of the calibration element 38 is implemented through thetranslation movements along Y and Z. A first positioning along Y allows the subsequent approaching along Z, and finally a further upwards translation allows obtaining the desired results, as shown in sequence in Figures 4B and 4C. By way of example, in the configuration in Figures 4A, 4B and 4C, the calibration element 38 is advantageously conical in shape, but a similar result could be obtained with the aforesaid cylindrical roller.

[0035] According to a first embodiment shown in Figures 3A- 3C and 5A-5C, the actuator 11, 11' can be a rotary actuator adapted to rotate the calibration element 38 between the resting position and the operating position in which it is adapted to interact with the thermoplastic spacer 3 along the substantially vertical direction y.

[0036] The rotation allows the calibration element 38 to switch from the retracted position in Figure 3A to the extracted position in Figure 3C. By doing this, the thermoplastic spacer 3 is brought back to the desired position of perpendicularity to the glass plate 2'. Such a condition is kept by spacer 3 also after the calibration element 38 has returned to the retracted position thereof should a sufficient time have passed between the application of the spacer and the intervention of the calibration element 38. Indeed, the material of the thermoplastic spacer has thus had achance to cool sufficiently and to reach a viscosity such as to make it resistant to the stress of the force of gravity. The tests performed with the various specific thermoplastic materials for making spacers of this type have shown that a cooling time between 3 and 10 minutes is sufficient to obtain the desired behaviour from the material, also depending on the room temperature. Preferably, this time interval is of about 5 minutes.

[0037] According to a possible embodiment, the calibration element 38 can be a cylinder. An embodiment of this type is shown in Figures 3A-3C, for example.

[0038] According to a possible alternative embodiment, the calibration element 38 can be a cone or a truncated cone.

[0039] Alternatively to the configuration in Figure 3C, it is possible to proceed as indicated in Figure 3D, in which the cylindrical calibration element 38 is brought to the active position while remaining at a certain angle of inclination with respect to the horizontal. In this case, the final position of the calibration element 38 is reached by means of a further upwards translation, along Y. As seen in Figure 3B, the contact surface is thus reduced between calibration element 38 and the thermoplastic spacer 3, also reducing the risk for the action of the calibration element 38 to leave unattractive defects on the surface of the spacer.

[0040] The calibration element 38 can be adapted to rotate around the rotation axis c thereof. Advantageously, the calibration device 10 can comprise motor means for rotating the calibration element 38.

[0041] Therefore, the rotation of the roller does not occur by dragging through contact with the thermoplastic material, rather autonomously by the roller itself, thus reducing the stresses on the thermoplastic material.

[0042] Advantageously, the calibration element 38, or the outer surface thereof, is made of and anti-adherent material.

[0043] A further configuration alternative is shown in Figures 5A and 5B, where the calibration element is a plate. The operation is similar to the preceding cases, with the difference of acting for one spacer segment at a time, at the longitudinal dimension of the plate used.

[0044] According to a possible embodiment, the translation and support means 30 can be adapted to rotate around an axis substantially parallel to the axis y to be released from the lower edge of the glass plate 2'.

[0045] Figures 6A and 6B show a side view of glass 2' close to the lower edge thereof, i.e., that usually used for the translation of the glass through the translation means 30. As shown in Figure 6A, in this area, the close position of the translation means 30 with respect tospacer 3 may not allow adequately positioning the calibration device. The solution consists in providing, at least in the segment involved by the intervention of the calibration device 10, the translation means 30 with rotation kinematics 42, allowing such translation means to be positioned in a released position, as shown in Figure 6B.

[0046] In Figure 8, the calibration device 10 is provided with translation along axis X by means of the actuators 17 and 17'. In such a configuration, it is no longer the glass to be moved through the translation and support means 30 and the movement means 20, rather the calibration device 10 actuates such a movement.

[0047] The apparatus 200 can be also used in the case of shaped glasses comprising inclined edges with respect to the substantially vertical direction, or curved edges. According to a possible embodiment, the calibration device 10 can be positioned due to the interpolation of the means described for interpolating the positions and following a predetermined trajectory.

[0048] In this respect, the apparatus can comprise a control unit (not shown) which, through an operator interface, can allow programming a determined trajectory according to the shape of plate 2'.

[0049] The method, in the essential form thereof, thuscomprises the following steps:(a) providing an apparatus (200) according to any one of the preceding claims;(b) inserting a plate (2') on which a thermoplastic spacer (3) is arranged inside the apparatus (200);(c) approaching the calibration device (10, 10') to a portion of the thermoplastic spacer (3) to be calibrated;(d) moving the calibration element (38, 38') at least along the substantially vertical direction (y) between a resting position and an operating position in which it is adapted to interact with the thermoplastic spacer (3) along the substantially vertical direction (y).

[0050] Step (c) can be performed by means of a translation or a rotation of the calibration element 38.

[0051] According to a possible embodiment, in the case of cylindrical, conical, or frustoconical calibration elements 38, in step (d), the calibration element 38 in the operating position can be rolled onto the thermoplastic spacer 3.

[0052] Advantageously, step (d) can be repeated, gradually increasing the height of the calibration element 38 with respect to the translation and support means. In essence, the desired shape of the thermoplastic spacer can be achieved with subsequent and incremental passages.

[0053] Therefore, the advantages achievable with thepresent invention are now apparent.

[0054] Firstly, an apparatus and a method have been provided, which are capable of allowing the extrusion of the thermoplastic spacer without the deformation thereof occurring due to the force of gravity prior to the assembly step.

[0055] At the same time, the cycle time of the line for producing the insulating glass has remained substantially the same.

[0056] Finally, the solution is adapted to ensure an appearance of the end product which is in line with the expectations and habits of the market even in the case of a thermoplastic spacer with thicknesses equal to or greater than 20 mm.

[0057] In order to meet specific needs, those skilled in the art may make changes to the embodiments described above and / or replace the elements described with equivalent elements without departing from the scope of the appended claims.

Claims

CLAIMS1. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass comprising translation and support means (30) adapted to translate at least one glass plate (2') along a direction (x), and lateral support means (35) adapted to sustain a glass plate (2') in a substantially vertical position; said apparatus further comprising at least one calibration device (10) adapted to modify the shape of a thermoplastic spacer arranged on a glass plate (2') and positioning means (36) adapted to position said calibration device (10) with respect to the plane defined by said lateral support (35) along the direction (x) and along a substantially vertical direction (y); said calibration device (10) comprising a calibration element (38, 38') which is movable at least along the substantially vertical direction (y) between a rest position and an operating position in which it is adapted to interact with the thermoplastic spacer (3) along the substantially vertical direction (y).

2. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to claim 1, characterised in that said translation and support means (30) are motorised rollers or a conveyor belt.

3. Apparatus (200) for calibrating a thermoplasticspacer (3) for insulating glass according to any one of the preceding claims, characterised in that it comprises movement means (20) which are adapted to grasp and move a glass plate (2'), preferably a carriage with suction cups.

4. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to the preceding claim, characterised in that the positioning means (36) comprise at least one motorisation (15, 15') for positioning at the desired height along the substantially vertical axis Y the calibration device (10, 10').

5. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of the preceding claims, characterised in that the calibration device (10, 10') comprises an actuator (11, 11') of a linear type for moving the calibration element (38, 38') along a direction (z) which is substantially perpendicular to the plane defined by the lateral support means (35).

6. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of the preceding claims, characterised in that the calibration device (10, 10') comprises an actuator (11, 11') adapted to rotate the calibration element (38, 38')between the rest position and the operating position, wherein it is adapted to interact with the thermoplastic spacer (3) along the substantially vertical direction (y).

7. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of the preceding claims, characterised in that the surface of the calibration element intended to come into contact with the thermoplastic spacer is made of anti-adherent material.

8. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of the preceding claims, characterised in that said calibration element (38, 38') is a cylinder.

9. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of claims 1-7, characterised in that said calibration element (38, 38') is a cone or a truncated cone.

10. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of claims 7-9, characterised in that said calibration element (38, 38') is adapted to rotate around a rotation axis (c) thereof.

11. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to thepreceding claim, characterised in that it comprises motor means for rotating said calibration element (38, 38').

12. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of claims 1-7, characterised in that said calibration element (38, 38') is a plate.

13. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of the preceding claims, characterised in that said translation and support means (30) are adapted to rotate around an axis which is substantially parallel to the axis (y) to release from the lower edge of the glass plate (2').

14. Apparatus (200) for calibrating a thermoplastic spacer (3) for insulating glass according to any one of the preceding claims, characterised in that it comprises actuators (17, 17') for translating along the X axis.

15. Method for calibrating a thermoplastic spacer comprising the steps of:(a) providing an apparatus (200) according to any one of the preceding claims;(b) inserting a plate (2') on which a thermoplastic spacer (3) is arranged inside the apparatus (200);(c) approaching the calibration device (10, 10') to a portion of the thermoplastic spacer (3) to be calibrated;(d) moving the calibration element (38, 38') at least along the substantially vertical direction (y) between a rest position and an operating position in which it is adapted to interact with the thermoplastic spacer (3) along the substantially vertical direction (y).

16. Method for calibrating a thermoplastic spacer according to the preceding claim, characterised in that said step (c) is performed by means of a translation or a rotation of the calibration element (38, 38').

17. Method for calibrating a thermoplastic spacer according to any one of claims 15-16, characterised in that in the event of cylindrical, conical or frustoconical calibration elements (38, 38'), in step (d) the calibration element (38, 38') in the operating position is rolled on the thermoplastic spacer (3).

18. Method for calibrating a thermoplastic spacer according to any one of claims 15-17, characterised in that step (d) is repeated, gradually increasing the height of the calibration element (38, 38') with respect to the translation and support means.

19. Method for calibrating a thermoplastic spacer according to any one of claims 15-18, characterised in that it comprises a step (c') prior to step (d) in which through the rotation kinematics (42), the translation and support means (30) are disengaged from the lower edge ofthe plate (2').

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