WO2004069511A1

WO2004069511A1 - Press apparatus for molding articles and relative method

Info

Publication number: WO2004069511A1
Application number: PCT/IB2003/004774
Authority: WO
Inventors: Mario Damo
Original assignee: G.M.P. Spa
Priority date: 2003-02-05
Filing date: 2003-10-28
Publication date: 2004-08-19
Also published as: ITUD20030026A1; AU2003274461A1

Abstract

Press apparatus and method for molding articles (31) covered by a covering film (32). The apparatus comprises a matrix (17) and a punch (24) and rotates between a first position facing towards the side of the plant and a second position facing towards the side of the operator (21). In the first position facing towards the side of the plant the matrix (17) is arranged in a low position, while in the second position facing towards the side of the operator (21) the matrix (17) is located in a high position in order to facilitate the removal of the article (31) and prevent any dirt or suchlike from falling inside it, and the punch (24) is arranged in a low position.

Description

"PRESS APPARATUS FOR MOLDING ARTICLES AND RELATIVE METHOD"

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FIELD OF THE INVENTION

The present invention concerns a press apparatus of the tilting type, and the molding method that uses said press apparatus, for molding articles, for example made of polyurethane material or other type, covered with a decorative film.

To be more exact, the present invention concerns a press apparatus of the so-called book type, wherein two components of the press, which- carry respective mold components, are movable from a first open position wherein the polyurethane material or suchlike is introduced, the molded piece is removed and the servicing operations are performed, to a second closed position wherein the material is polymerized and molded in order to obtain the desired final form.

BACKGROUND OF THE INVENTION Known procedures for molding articles differ from each other in the base material used and in the technique for finishing the surface of the article obtained.

In such processes, the introduction of the material can occur with the mold open or closed. When the introduction takes place with the mold open, one of the components can be opened with respect to the other with a book-like movement in order to allow the close-up positioning of a casting head that introduces the material, or mixture, into the matrix element. When the introduction of the material is complete, the mold is closed and, when the molding is complete, the two components are opened, the piece is removed and the mold is cleaned and made pristine again for the subsequent cycle.

Press apparatuses of the traditional type are either of the type that can be translated to move between various positions, in each of which one step of the operating cycle is carried out, or of the type substantially fixed to the ground. Presses of this second type have the disadvantage that they oblige the operator, at least during some steps, to- stand inside the working area of the operating systems and members of the plant during the operations to remove the piece, cleaning operations and other possible servicing operations. This entails the risk that the operator might come into contact with moving mechanical members and in any case might not be in a condition of safety.

Traditional presses, moreover, normally have the matrix located underneath and the punch located above. Therefore, at the end of the molding step, after the press has been opened, the punch is in a high position, which is inconvenient for the cleaning and servicing operations that the operator has to carry ou .

Moreover, the use of chemical products for cleaning the punch can lead to the formation of dirt inside the matrix, which can create rejects in production or a lowering of quality in the subsequent cycle.

Examples are known of tilting presses, for example mounted on a drum as in FR-A-2.743.747 , or presses pivoting alternately with respect to two pins to which they can selectively be attached, as in EP-A-0.841.139.

Such solutions do not refer to molding cycles for articles covered with decorative films, transported and positioned by automated means. Moreover, such solutions do not provide a precise and systematic coordination between the positions that the elements of the mold, matrix and punch, alternately adopt, and the individual steps of the molding cycle, in particular the positioning of the film in the matrix, introduction of the molding material, extraction of the molded article, cleaning, restoration and replacement of the elements of the mold, etc. Furthermore, they have problems in terms of ease of access, removing the article, maintaining cleanliness, and other disadvantages. Applicant has devised, tested and embodied the present invention to overcome these shortcomings of the state of the art and to obtain f rther advantages .

One purpose of the present invention is to achieve a press apparatus for molding articles wherein, once the polymerization or molding is complete, the relative mold components are positioned so as to facilitate the intervention of an operator to carry out cleaning and/or restoration operations, and also the operations to apply possible inserts or other servicing operations.

Another purpose is to facilitate automated operations within the operating cycle, also achieving a press that puts the operator in a condition to perform all the operations while remaining in a position of substantial safety.

SUMMARY OF THE INVENTION The present invention is set forth and characterized in the main claims, while the dependent claims describe other innovative characteristics of the invention. The present invention comprises a press apparatus operating with mold means including at least matrix means and at least punch means, and provided with a first part functioning as a support for at least a matrix element, and a second part functioning as a support for at least a punch element.

The first and second parts have a first position of reciprocal opening and a second position of reciprocal closing. For example, in the case of a mold with a book- type opening, the two parts are pivoting together and the second part rotates with respect to the first part by about 90° or more, to pass from the first open position to the second closed position. According to one characteristic of the present invention, the press apparatus is able to be rotated from at least a first position facing towards the plant, wherein, when the mold is open, at least the introduction of the material into the matrix element takes place, to at least a second position facing towards a servicing zone, or the operator's zone, wherein, when the mold is open, at least the removal of the article takes place and the components of the mold are restored for the subsequent cycle. In a preferential embodiment, the press can rotate continuously for an angle of 180° and more, advantageously for at least 150°, to be arranged in a plurality of different angular positions according to the progress of the cycle to mold the article. In the case where articles covered with a film are produced, in the first position facing towards the plant the film is also positioned on one of the elements of the mold and formed.

According to^' the invention, the second position is substantially tilted with respect to the first position so that, when passing from one position to the other, the two parts of the mold invert their reciprocal position, that is, the part that in the first step of the cycle is in the lower position is taken above, and vice versa. A first advantage of the present invention is that the operator can always maintain a position such that he does not come into contact with moving members of the plant.

In fact, since the apparatus can be tilted during the operating cycle, it is presented to the operator open towards the outer side of the production plant in order to discharge the piece and perform the servicing operations; during the first steps, on the contrary, it is arranged open towards the other apparatuses of the plant in order to cooperate with the various mechanical members, possibly automated, functional to the cycle.

Another advantage is given by the fact that, at the start of the cycle to form a new piece, the matrix is held in a low position in order to facilitate the operations to introduce the material and to position and form the covering film. Thanks to this tilting, at the end of the cycle the matrix moves to a high position whereas the punch goes low; this facilitates the operations to discharge the molded piece from the matrix, and also the cleaning and application of possible inserts, or of the anti-adhesive material, in the punch, without running the risk of dirtying the surface of the matrix which is high, for example with detergent substances, with the anti-adhesive material itself or with possible flashes that can become detached from the punch.

This is particularly important since the surface of the matrix defines the aesthetic side of the article. Therefore, even small fragments of impurities that might remain on the bottom of the matrix can mark the covering film in the subsequent molding cycle and entail a decline in quality of the article obtained, which can even lead to the need to eliminate it. With the present invention this problem is avoided since, as we have said, during the step when the article is removed the matrix is up high and the punch is down low.

The molding method that uses the tilting press as described above provides a first step, with the mold open and facing towards the plant, wherein a film is applied and thermoformed on the surface of one of the components, matrix or punch, and the base material is cast or injected by means of one or more introduction members; a second step wherein the mold is closed and the material is polymerized and molded; a third step, which can be at least partly superimposed temporally with the first, wherein the press is tilted, thus inverting the reciprocal position of its components; a fourth step wherein the mold is opened, towards the servicing zone, or the operator's zone, and the piece is discharged; and a fifth step wherein the components of the mold are at least cleaned and restored for the subsequent cycle and all the servicing operations necessary to start the subsequent cycle are carried out. According to a variant, it is possible to provide at least a specific angular position of the press in order to facilitate the operations to change at least part of the mold elements. In a further variant, at least a specific angular position is provided, with the matrix - slightly inclined with respect to the horizontal, in order to facilitate the distribution of the material over the whole surface of the matrix and also the discharge of air during the introduction or casting step.

BRIEF DESCRIPTION OF THE DRAWINGS These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein: - figs. 1 to 8 show in sequence, with a partly sectioned side view, the sequence of the operating steps of the method that uses a press apparatus for molding articles according to the present invention. DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF EMBODIMENT With reference to the attached figures, an apparatus 10 for molding articles comprises a book-type press 11 mounted rotatable on a supporting structure 12. The apparatus 10 can be an integrating part of a plant for the production of articles, for example made of polyurethane and covered with an aesthetic film 32.

The book- ype press 11 is provided with a first part, or base plane, 13 and a second part, or cover, 14 pivoting together and reciprocally movable, due to the presence of an opening/closing actuator 25 associated with the cover

14, from a first open position to a second closed position.

In this case, the function of the base plane 13, as will be seen in more detail later, is to support and move the matrix element 17 of the mold, while the function of the cover 14 is to support the punch element 24.

Inside the base plane 13 a first movable plane 15 is mounted, associated with a relative pressing actuator 26, the function of which is to move the elements 17, 24 of the mold together/apart during the molding and polymerization cycle .

On the first movable plane 15 a second movable plane 16 is also mounted, which in turn supports the matrix element 17. The second movable plane 16 is associated with linear actuators 18 that can be selectively activated, having a travel that can be regulated according to the height of the mold, and is driven during the step when the molded article 31 is discharged, as will be seen in more detail later. ^■ The book-type press 11, furthermore, is rotatable, around a substantially horizontal axis, in this case by means of a tilting mechanism 27 of the type comprising a toothed wheel 29 and a corresponding toothed track 30. The tilting mechanism 27 allows to make the book-type press 11 adopt substantially any angular position whatsoever between two limit positions, respectively a first position with the open mold facing towards the plant and a second position with the open mold facing towards the operator 21, according to the specific step in progress of the polymerization and molding cycle.

To be more exact, in the first position with the mold facing towards the plant, it is possible to carry out, for example using automated mechanical members 19 and 20, as will be seen hereafter, at least the operations to position the covering film 32 in cooperation with the surface of one of the mold elements 17 or 24, and to introduce the material into the molding seating. In the second position with the mold facing towards the operator 21, it is possible to carry out at least the operations to discharge the molded article 31 and to clean and restore the mold elements 17 and 24.

In this case, the book-type press 11 is arranged, in the first position, with the matrix element 17 in a low, substantially horizontal position, while the open cover 14 faces towards the zone where the operating members 19, 20 of the plant are moved.

To pass from the first to the second position the book-type press 11 rotates, in this case, by an angle of between about 120° and 150°, advantageously between 130° and 140°, inverting the positions of the matrix element 17 and the cover 14, with the open elements of the mold now facing towards the operator 21. According to a variant, from the first position wherein the lower plane 13 lies on a substantially horizontal plane a further rotation of the book-type press 11 is provided, for example by an angle of between about 10° and 20°, in order to adopt a position with the plane 13 slightly inclined and thus encourage both the correct distribution of the cast material in the matrix element 17 and also the discharge of air. According to another variant, a further angular movement of the book-type press 11 is provided in order to take the cover 14, when it is open on the operator's side, to a substantially horizontal position and thus facilitate the change-of-mold operations. It is clear that the angles indicated above are purely indicative and can vary according to the size of the book- type press 11, the position and size of the other operating members of the plant and the specific requirements of the operator 21. In this case, two mechanical arms, or robots, alternately cooperate with the book-type press 11, respectively a first 19 to deposit a covering film 32 in the matrix element 17, and a^' second 20 to introduce the material into the matrix element 17. The molding apparatus 10 as described heretofore is used as follows.

As shown in fig. 1, when the previous molding cycle has finished, the apparatus 10 is in its second position to discharge the piece, with the cover 14 open and facing towards the operator 21, and has been prepared for a new molding cycle. The book-type press 11 (fig. 2) is then made to rotate, in this case by about 135°, so as to move to the first operating position with the open cover 14 facing towards the production plant . As shown in fig. 3, in a loading step, by means of the first mechanical arm 19, a covering film 32 is laid on the matrix element 17, in this case by means of a movable plane 22 equipped with pneumatic retaining means. According to a variant, during the transfer step, the covering film 32 is heated and/or pre-formed by means of said movable plane 22. In a subsequent step (fig. 4) , or introduction step, the base plane 13 is rotated backwards, in this case by a further 15°, to arrange the matrix element 17 slightly inclined with respect to the horizontal. Then, by means of the second mechanical arm 20 that supports a casting head 23, the material is introduced inside the matrix element 17, above the covering film 32 previously laid. Once the material has been introduced (fig. 5) , the cover 14 moves to the position of reciprocal closure with respect to the base plane 13 and these elements are clamped together by means of hooks 28 to ensure the mold is closed. In this step, in known manner, the first movable plane 15 is driven upwards in order to displace the matrix element 17 towards the punch element 24 (fig. 6) .

While polymerization is in progress, the book-type press 11 is rotated by about 135° (fig. 7), to take it to the second position for the discharge of the piece, with the base plane 13 now up and the cover 14 down.

When the polymerization of the material is finished (fig. 8) , the cover 14 is taken to the first open position with respect to the base plane 13.

The second movable plane 16 is then driven to thrust the matrix element 17 and the article 31 outwards, through a travel in the range of 250-350 mm, and thus facilitate the removal and discharge thereof by the operator 21.

Thanks to this position of the base plane 13, the operator 21 is easily able to perform the operations to discharge and unload the article 31, while the low position of the cover 14 facilitates operations to clean and prepare the punch element 24.

The tilted position of the book-type press 11 also allows the operator 21 to perform all these operations in good safety conditions since, as can be seen from the figures, he is always in the same position, without ever needing to position himself towards the production plant, with the risk, for example, of coming into contact with the mechanical arms 19 and 20.

Moreover, the position of the book-type press 11 during the cleaning step allows the operator 21 to perform these operations with the punch element 24 lowered, and therefore without the risk of the material dripping or falling into the matrix element 17. This guarantees the cleanliness of the matrix element 17, which is thus immediately ready for the start of the subsequent molding cycle, and for the insertion into it of a covering film without any risk of the film being marked and/or ruined in any other way by impurities and fragments.

It is clear however that modifications and/or additions of parts and steps can be made to the apparatus 10 and method as described heretofore, without departing from the field and scope of the present invention.

For example, the matrix element 17 and the punch element 24 can have two or more impressions. Further angular positions of the book-type press 11 can also be provided in order to carry out other preparation operations that are not mentioned here. Furthermore, the plane 13 and the cover 14 can open and close with respect to each other in a different manner from the book-type manner described here.

It is also clear that, although the present invention has been described with reference to specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of press apparatus for molding articles and relative method, all of which shall come within the field and scope of the present invention. For example, the press could at least partly rotate on a substantially vertical or inclined axis instead of with respect to the horizontal axis as described here.

Claims

1. Press apparatus for molding articles (31) covered by at least a covering film (32), comprising a first part, or base plane, (13) supporting a matrix element (17), and a second part, or cover, (14) supporting a punch element (24), said matrix element (17) and said punch element (24) reciprocally having a first open position and a second closed position, said press apparatus (11) being able to rotate between a first position facing towards a first side, or side of the plant, where there are positioning means (19, 22) to position said film (32) and/or introduction means (20, 23) to introduce the molding material, and a second position facing towards a second side, or side of the operator (21) , where at least the removal of the article (31) occurs, characterized in that in said first position facing towards the side of the plant said base plane (13) and the relative matrix element (17) are arranged in a low position in order to cooperate with said positioning means (19, 22) to position the film (32) and with said introduction means (20, 23) to introduce the molding material, and in that in said second position facing towards the side of the operator (21) said base plane (13) and the relative matrix element (17) are located in a high position in order to facilitate the removal of the article (31) and prevent any dirt or suchlike from falling inside it, and said cover (14) and the relative punch element (24) are arranged in a low position.

2. Press apparatus as in claim 1, characterized in that it is able to rotate in a substantially continuous manner through an angle of 180° and more, to be arranged in a plurality of different angular positions functionally associated with the progress of the cycle to mold said article (31) .

3. Press apparatus as in claim 1 or 2 , characterized in that it comprises a first movable plane (15) associated with said base plane (13) and able to be selectively driven to displace said matrix element (17) towards said punch element (24) .

4. Press apparatus as in claim 3, characterized in that it comprises at least a second movable plane (16) associated with said first movable plane (15) and able to be selectively driven at least during the step when said article (31) is removed.

5. Press apparatus as in any claim hereinbefore, characterized in that it is able to adopt at least a specific angular position with the base plane (13) inclined with respect to the horizontal and facing towards the side of the plant at least during the step when the molding material is introduced in order to facilitate the distribution thereof on the surface of said matrix element (17) and the discharge of air.

6. Press apparatus as in any claim hereinbefore, characterized in that it is able to adopt at least a specific angular position with the cover (14) arranged substantially horizontal and facing towards the side of the operator (21) in order to perform operations to change the mold elements.

7. Press apparatus as in any claim hereinbefore, characterized in that it is pivoting according to a substantially horizontal axis to a supporting structure (12) .

8. Press apparatus as in any claim hereinbefore from 1 to 6 inclusive, characterized in that it is pivoting according to a substantially vertical or inclined axis to a supporting structure (12).

9. Press apparatus as in claim 7 or 8 , characterized in that it comprises a tilting mechanism (27) able to rotate said parts (13, 14) by an angle of 180° and more with respect to said supporting structure (12).

10. Press apparatus as in any claim hereinbefore, characterized in that said first position is rotated by an angle of between 120° and 150° with respect to said second position.

11. Method for molding articles (31) covered by a film (32) in a press apparatus (11) comprising a first part, or base plane, (13) supporting a matrix element (17) and a second part, or cover, (14) supporting a punch element (24), said parts (13, 14) having reciprocally a first open position and a second closed position, said press apparatus (11) cooperating with positioning means (19, 22) to position said film (32) and/or with introduction means (20, 23) to introduce the molding material, characterized in that it provides :

- a first step with said parts (13, 14) reciprocally open, wherein said film (32) is positioned by said positioning means (19, 22) in cooperation with said matrix element (17) and the molding material is introduced by said introduction means (20, 23) inside said matrix element (17), arranged in a low position, and above said film (32);

- a second step wherein said parts (13, 14) are closed and the molding material is polymerized;

- a third step wherein the press apparatus (11) is tilted by at least 90°, taking said matrix element (17) to a high position and facing towards the side of the operator (21) ;

- a fourth step wherein said parts (13, 14) are opened and the article (31) is discharged from said matrix element

(17) ;

- and a fifth step wherein at least the matrix (17) and punch (24) elements are cleaned and prepared for the subsequent cycle.