WO2015033272A1

WO2015033272A1 - Swarf collecting element for mould holder station

Info

Publication number: WO2015033272A1
Application number: PCT/IB2014/064217
Authority: WO
Inventors: Ettore Bordin; Stefano PELLIZZARI
Original assignee: Stemma Srl
Priority date: 2013-09-04
Filing date: 2014-09-03
Publication date: 2015-03-12
Also published as: ITTV20130141A1; DE112014004030T5

Abstract

The present invention relates to a mould-holder station (10) for a machine for moulding polymer material by casting or injection inside a mould (14) mounted in the mould- holder station (10), the mould (14) comprising at least a base (15) and two side rings (16), The mould-holder station (10) comprises at least one mould-holder block (11) for fixing the two side rings (16) of the mould (14), and an actuating unit (12) for moving the support plate (17) for the base (15) of the mould (14); the actuating unit (12) being arranged underneath the mould-holder block (11); In accordance with the invention the mould-holder station (10) is characterized in that a collection element (20) is removably provided in a space defined by a bottom surface (31) of the mould-holder block (11) and by a top surface (32) of the actuating unit (12), said collection element being separate from and independent of the mould-holder block (11) and suitable for collecting any machining waste and/or release agent sprayed outside of the mould (14) mounted in the mould-holder station (10).

Description

SWARF COLLECTING ELEMENT FOR MOULD HOLDER STATION

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DESCRIPTION

The present invention relates to a mould-holder station for machines for moulding polymer material, in particular by means casting or injection.

More particularly, even though not exclusively, the present invention relates to a mould-holder station for a static or rotary machine for moulding polymer material by casting or injection for obtaining articles such as soles and footwear.

It is known to use rotary machines with several stations for the production of single or multi-component soles in one or more colours. It is also known to use rotary machines for the production of footwear by means of direct injection, onto the upper, of single or multi- component soles made of polymer material.

These rotary machines are generally composed of one or more injection units and a robust base on wliich a rotating carousel suitable for supporting a plurality of mould-holder stations is mounted.

Each injection unit has an injection/casting head by means of which the polymer material is injected or cast inside moulds housed inside the various mould-holder stations of the rotating carousel.

The known mould-holder stations usually comprise a mould-holder block and an actuating unit wliich are joined by means of a suitable fixing system to die base of the rotating carousel. The two rings of the mould are mounted on the mould-holder block, while the actuating unit, wliich is arranged underneath the mould-holder block, allows movement of the support on which the mould base is mounted.

Each mould-holder station may also comprise a shoe last-holder or cover-holder unit which supports the lasts and/ or covers designed to cooperate with the other components of the mould mounted on the mould-holder block, during the various stages of injection of the polymer material inside the mould.

The type of machine described above briefly, being well-known to the person skilled in the art, is used in particular for the production of articles where at least one component is made of compressed or expanded polyurethane.

It is known that the use of this type of material involves the use of release agents for facilitating, once the moulding cycle has been completed, the extraction of the finished product from the mould. Characteristically, in fact, the polyurethane has a high force of adhesion to the inner walls of the mould into wliich it is injected or cast, such that it would be extremely difficult to extract the finished article if release agents were not used.

However, even tiiough now considered to be indispensable, the use of release agents involves certain drawbacks.

As mentioned, these release agents are generally sprayed onto the inner walls of die mould using ordinary spraying devices and not infrequendy some of die release agent is sprayed, due to error or imprecision, outside of the inner walls of the mould.

The release agent sprayed outside the mould may be deposited for example on the mould-holder block or on die structure of die actuating unit of die mould-holder station. From here the release agent may trickle down onto the od er components of the mould- holder station until, in some cases, it is deposited on the floor on which the rotary machine is standing.

The release agents are usually oily liquids and it is therefore clear tiiat it is important to prevent them from being deposited on the moving parts of die mould-holder station as well as on the floor.

In order to overcome diis drawback it is common practice to spread sheets/ cloths of absorbent material below the mould-holder stations of the machine. The cloths have die function of preventing the release agents from soiling the floor. It is also known to position underneath the mould-holder stations collection tanks, instead of the cloths of absorbent material.

It is clear, however, diat these solutions are makeshift solutions which are able to prevent soiling of the floor on which the machine is standing, but cannot prevent some of the release agent sprayed outside the mould from being deposited on parts and components of the mould-holder stations which are difficult to access.

These depositions, which accumulate over time, become difficult to remove and, being oily, retain die dust and impurities which are deposited on diem until they form widi time actual incrustations. The presence of such depositions makes it difficult to perform maintenance of die machine parts and components.

It must also be noted how, during moulding of polymer materials such as both compressed and expanded poiyurethane and similar materials, it frequently happens that small amounts of polymer material escape from the mould. In this case also die polyuretiiane which comes out of the mould may also be deposited on the floor or enter into the spaces present between the various components of die mould-holder stations of the machine.

Bodi in the case of die release agent and in the case of die poiyurethane, any machining residues which are deposited for example between the block-holder zone and the various mechanical operating parts of the mould-holder station may be difficult to reach both because the space available for an operator to insert a hand or tool, as necessary, in order to remove manually these residues, is very small, and because the mould-holder station has a plurality of components which during normal operation are in movement.

Any machining waste, which has become lodged in parts of the mould-holder station of the machine which are difficult to access, may sometimes be removed only by disassembling the various components of die mould-holder station and/or the rotating carousel. In order to avoid undesirable stoppage of the machine, this cleaning operation is performed only when a general maintenance of die machine is performed. However, in extreme cases, some waste may become lodged in moving parts of the mould-holder station, affecting operation of die machine before the general maintenance is carried out.

The object of die present invention is therefore to solve at least partially the aforementioned longstanding drawbacks affecting machines of die known type for moulding polymer material by casting or injection and in particular the mould-holder stations of these machines.

In particular a task of the present invention is to provide a mould-holder station of a machine for moulding polymer material by casting or injection suitable for collecting any release agents sprayed outside of the surfaces of the mould mounted in the mould-holder station, the portion of release agent which naturally trickles down from the surface of the mould, and/ or any machining waste.

Furthermore, a task of die present invention is to provide a mould-holder station of a machine for moulding polymer material by casting or injection suitable for collecting any release agents sprayed outside of the surfaces of the mould mounted in the mould-holder station, the portion of release agent which naturally trickles down from die surface of the mould, and/ or any machining waste in a simple and low-cost manner.

Yet anodier task of the present invention is to provide a mould-holder station of a machine for moulding polymer material by casting or injection suitable for collecting any release agents sprayed outside of the surfaces of the mould mounted in die mould-holder station, die portion of release agent which naturally trickles down from the surface of die mould, and/or any macl ining waste, so as to not interfere with the normal operation of the mould-holder station.

The aforementioned object and tasks are achieved by a mouid-hoider station of a machine for moulding polymer material by casting or injection according to Claim 1.

The characteristic features and the further advantages of die invention will become clear from the description hereinbelow of a number of examples of embodiment provided by way of a non-limiting example witii reference to the accompanying drawings in which:

Figure 1 shows schematically a mould-holder station of a moulding machine of the known type;

Figure 2 shows schematically a partially exploded view of a mould-holder station of a moulding machine according to the invention;

Figure 2A shows schematically a cross-sectional view, not to scale, along a generic transverse plane, of a detail of a mould-holder station according to the invention and die mould mounted therein;

Figure 3 shows schematically view similar to that of Figure 2, but in a different operating configuration;

Figure 4 shows a schematic perspective view of a mould-holder station according to the invention;

Figure 5 shows a schematic view of the mould-holder station according to Figure 4, but from a different perspective;

Figure 6 shows a schematic view of the mould-holder station according to Figure 4, but from a different perspective.

As already mentioned, the present invention relates to a mould-holder station for a machine for moulding polymer material by casting or injection.

In particular, although not exclusively, the present invention relates to a mould-holder station of a static or rotary moulding machine comprising a plurality of mould-holder stations.

An example of such a type of machine consists of the rotary machines for performing direct injection, onto an upper, of single or multi-component soles, for example soles with a tread or midsole made of polyurethane, or soles widi a tread made of rubber or some other thermoplastic material, and a polyurethane midsole.

Another example of a rotary machine comprising a plurality of mould-holder stations consists of rotary machines used for producing single or multi-component soles.

In these machines the mould-holder stations may be moved (automatically) or the injection/casting unit of tlie machine may be moved (manually or automatically).

Figure 1 shows by way of example a known mould-holder station 10 of a multi-station automatic rotary machine for direcdy injecting soles onto an upper.

The mould-holder station 10 may comprise at least one mould-holder block 1 1 , an actuating unit 12 and a shoe last-holder or cover-holder unit 13.

The actuating unit 12 is arranged underneadi the mould-holder block 11 , while the shoe last-holder or cover-holder unit 13 is arranged above the mould-holder block 1 1.

With specific reference to Figure 2A, a mould 14 which may comprise in turn a base 15, two side rings 16 and a cover may be mounted in the mould-holder station 10.

The base 15 may be fixed to a support plate 17 which is moved along a direction perpendicular to the direction of extension of the base 15 by means of an actuating stem 18 operated by the actuating unit 12. This direction of movement is indicated in Figure 2A by the arrows F.

The side rings 16 may be fixed in the mould-holder block 1 1. The side rings 16 are divided from each other by a central longitudinal plane and, in a known manner, are displaced so as to move towards and away from each other by means of proper actuators which are arranged inside the mould-holder block 11. The direction of movement of the rings is indicated in Figure 2A by the arrows T.

The cover of die mould 14 may be fixed on the last-holder or cover-holder unit 13 of the station 10.

In the embodiment shown in die accompanying figures, the bottom surface of the last 19 acts as a cover of the mould 14, the upper of a shoe being mounted on said last in the case of direct injection-moulding onto an upper. This upper is dien completed with injection of the sole.

In a known manner, a cover fixed on the last-holder unit 13 and having a suitably shaped inner surface may also act as a cover of the mould 14.

The mould-holder station 10 according to die invention is characterized in diat a collection element 20 is removably arranged in a space defined by a bottom surface 31 of the mould-holder block and a top surface 32 of the actuating unit 12, said collection element 20 being separate from and independent of die mould-holder block 1 1 and being suitable for receiving and collecting machining waste and/or any release agent sprayed outside of the mould 1 mounted in the mould-holder station 10.

In one embodiment, this collection element 20 is a cleaning box.

Owing to its particular position underneath the mould-holder block 1 1 and the support plate 17, the collection element 20 is able to collect the machining waste and any release agent sprayed outside of the mould 14, or spilling from the mould 14, before it is deposited on the floor supporting the machine or before it becomes lodged in zones of the mould-holder station which are difficult to reach.

Moreover, die collection element 20, being positioned between the mould-holder block 1 1 and the actuating unit 12, occupies a space in die mould-holder station 10 which can be easily accessed by an operator, and therefore removal of the collection element 20, where necessary, is facilitated and may be performed by merely removing any protective covers provided on the station 10. These protective covers are normally required by law in order to safeguard the operator.

Furthermore, the collection element 20, owing to its particular position, while ensuring effectively the collection of any machining waste and/or release agent, is independent of the opening and closing movements of die mould 14 due to the mould-holder block 1 1. The collection element 20, in fact, during normal use remains stationary.

Moreover, removal of die collection element 20 may be performed without interfering with parts of the mould 14 or the mould-holder block 1 1 or the support plate 17 and in turn replacement of the mould 14 is not hindered or conditioned by specific manoeuvring of the mould-holder block 1 1.

The collection element 20 may be removably fixed by means of guides 22 to the bottom surface 31 of the mould-holder block 11 or to die top surface 32 of the actuating unit 12.

The accompanying figures show schematically the embodiment in which the collection element 20 is removably fixed to the top surface 32 of the actuating unit 12.

In the case where the collection element 20 is removably fixed to the bottom surface of the mould-holder block 11 , the fixing guides will be arranged so as not to hinder the opening and closing movements of the mould-holder block.

Advantageously, in order to facilitate the collection of oily liquids, such as the release agents which are commonly used, preventing them from clinging to the surfaces of the collection element 20, the latter may be lined with a covering cloth 21 made of textile material or non-woven fabric.

This covering cloth 21 may be removably fixed to a top surface of the collection element 20.

Once the operator of the machine sees that the cloth 21 is no longer able to absorb the liquids with which it comes into contact, being duly impregnated with waste material, the collection element 20 may be removed from its seat and the cloth 21 replaced with a clean one.

As already mentioned, the collection element 20 may be a cleaning box 20 with dimensions similar to those of the bottom surface of the mould-holder block 1 1 , when in its closed position, i.e. when the rings 16 of the mould 14 are arranged in contact with each other.

As shown in the accompanying figures, the cleaning box 20 may be U-shaped. In this way the box 20 may be arranged inside its operating seat so as to surround at least partially the actuating stem 18 of the actuating unit 12. In greater detail, as can be clearly seen in Figure 2A, the cleaning box 20 may be arranged so as to surround the fixed base 23 of the actuating stem 18 operated by the actuating unit 12.

Advantageously, this embodiment therefore ensures that there is no interference with the normal operation of the mould-holder station and that the movements of the actuating stem 18 of the actuating unit 12 are not hindered.

As clearly shown in Figures 5 and 6, an inclined shelf 25 may be provided in the region of the bottom surface 31 of the mould-holder block 1 1. This inclined shelf 25 is preferably mounted on the side of the mould-holder block 1 1 opposite to that directed towards the operator if present, i.e. on the side which most difficult to access.

The surface 25 has the function of conveying into the collection element 20 any machining waste and/or release agent sprayed outside of the mould.

The arrangement of the inclined shelf 25 is such that the dimensions of the collection element 20 may be reduced.

As already mentioned, according to an alternative embodiment of the machine according to the invention, not shown in die drawings, since it may be easily imagined by a person skilled in the art, the access to die space in which the collecdon element 20 is provided is protected by a safety door. This safety⁷ door has die function of preventing an operator from accidentally making contact widi die zone occupied by die collection element 20 during operation of die machine.

On the basis of die description provided above, it may therefore be understood how the arrangement of a collection element 20 in the space situated between die bottom surface 31 of the mould-holder block 1 1 and die top surface 32 of the actuating unit 12 is able to provide a solution to the aforementioned problems of the prior art.

In particular, it will now be clear how the solution proposed is simple to produce and low-cost. The collection element 20 may in fact be made of sheet metal which is not costiy and does not require particular machining operations.

Also the provision, where necessary, of the covering cloth 21 may be simply achieved and does not involve an excessive cost.

Moreover it is clear how, owing to its positioning undernead the working surface of the machine and owing also to the arrangement of the inclined collection shelf, the collection element 20 described above is able to niininiize the amount of machining waste and release agent which is deposited on the floor where the machine is standing or which remains trapped inside the mould-holder station.

On die one hand diis helps avoid, as described above, having to resort to extraordinary maintenance of die machine in order to eliminate any residue trapped in moving parts of die mould-holder station, while ensuring that there is also a cleaner working environment.

Moreover, the provision of die collection element 20 does not involve structural modifications to die mould-holder station 10, occupying a space which hidierto was not used in die known mould-holder stations 10.

Advantageously, therefore, the mould-holder stations 10 of existing moulding machines may be equipped with a collection element 20 such as that described above. It is in fact merely required to fix suitable guides to die bottom surface 31 of the mould-holder block 1 1 or to die bottom surface 32 of the actuating unit 12 in order to allow correct positioning of die collection element 20.

Furthermore, die solution described is simple to use. Once the operator sees that the collection element 20 is full of waste material, the mould-holder block may be removed from its seat and emptied and then put back into position.

As mentioned, in die case where the collection element 20 is provided with the covering cloth, it is sufficient to replace the covering cloth used up to then widi a new one.

The person skilled in die art may make modifications to the embodiments of the mould-holder station described above and/or replace the parts described with equivalent parts, without thereby departing from die scope of the accompanying claims.

For example, in place of tlie collection element /cleaning box, it is possible to provide two half-diaphragms which are movable laterally with respect to the front of die mould- holder station between an extracted position (utilisable for example in order to replace a sheet for collecting any machining waste and release agent sprayed outside of the mould), and a working position situated underneadi the mould-holder block, the adjacent edges of the two said half-diaphragms being provided widi semi-circular recesses so as to embrace die actuating rod 18.

For the purposes of application of die present invention, the combination of two side rings widi the base of the mould is not indispensable, since die essential characteristic feature is that die collection element 20 is arranged underneadi the base of the mould.

Claims

1. Mould-holder station (10) for a machine for moulding polymer material by casting or injection inside a mould (14) mounted in the mould-holder station (10), the mould (14) comprising at least a base (15) and two side rings (16),

the mould-holder station (10) comprising at least one mould-holder block (11) for fixing the two side rings (16) of the mould (14), and an actuating unit (12) for moving a support plate (17) for the base (15) of the mould (14); the actuating unit (12) being arranged underneath the mould-holder block (11);

the mould-holder station (10) being characterized in that a collection element (20) is removably provided in a space defined by a bottom surface (31) of the mould-holder block (1 1) and by a top surface (32) of the actuating unit (12), said collection element being separate from and independent of the mould-holder block (11) and suitable for collecting any machining waste and/or release agent sprayed outside of the mould (14) mounted in the mould-holder station (10).

2. Mould-holder station (10) according to Claim 1 , wherein the collection element (20) is lined with a covering cloth (21) made of textile material or non-woven fabric, said covering cloth (21) being removably fixed to a top surface of the collection element (20).

3. Mould-holder station (10) according to Claim 1 , wherein the collection element is a cleaning box (20), said cleaning box (20) being U-shaped so as to surround at least partially an actuating stem (18) of the actuating unit (12), the actuating stem (18) being fixed to the support plate (17).

4. Mould-holder station (10) according to Claim 1 , wherein the collection element (20) is fixed by means of guides (22) to the bottom surface (31) of the mould-holder block (11) or to the top surface (32) of the actuating unit (12).

5. Mould-holder station (10) according to Claim 1 , wherein an inclined shelf (25) for conveying the machining waste and/or the release agent sprayed outside of the mould (14) into the collection element (20) is provided in the region of the bottom surface (31) of the mould-holder block (11).

6. Mould-holder station (10) according to Claim 1 , wherein the access to the space in which the collection element (20) is provided is covered by a protection door.

7. Rotary machine for direcdy injecting single or multi-component soles onto an upper, comprising at least one mould-holder station (10) according to any one of Claims 1 to 6.