FR2650527A1 - MACHINE FOR MANUFACTURING CONTAINERS IN THERMOFORMABLE SYNTHETIC MATERIAL - Google Patents

Abstract

The machine comprises a station (11) for loading preforms for hollow parts to be moulded in thermoforming material, two ovens (13, 14) for heating said preforms, a first blow moulding press (15), a second blow moulding press (16) and two stations (17, 18) for recovering or removing products following moulding. The preforms are arranged on pallets A which move on a circuit including chiefly a central rail section (29) having the loading station (11) located therein and lateral rail sections (19, 20) on which are located the heating ovens and the blow moulding presses. The pallets may be rectangular or square. The presses (15, 16) are coupled and actuated by a known device such as, for example, a hydraulic or pneumatic jack (52).

Description

MACHINE FOR MANUFACTURING CONTAINERS IN THERMOFORNABLE SYNTHETIC MATERIAL
The present invention relates to a machine for manufacturing containers of the type bottles, cans, etc., of thermoformable synthetic material, according to a blowing process, comprising means for loading preforms, means for heating these preforms and means for blowing these pre-heated preforms.

Known machines of this type usually include a station for loading preforms, a station for heating these preforms, a blowing press and finally a station for unloading molded products.

One of the problems with these machines is that of the difference in time required for processing at each station. It turns out that in these equipments the heating of the preforms takes significantly longer than their loading, the evacuation of the finished products and the blowing proper.

To increase productivity, it is of course possible to double the line by multiplying all the stations by two. Theoretically this solution is able to double the production rate, but in practice it is expensive, bulky and unreliable. Managing two complete lines in parallel proves to be complex and creates disturbances that are difficult to control.

The invention therefore proposes to overcome these drawbacks by offering a machine which allows a noticeable increase in the production rate without its cost being disproportionately increased and without its management being made significantly more complicated.

For this purpose, the machine according to the invention is characterized in that the means for loading the preforms comprise at least one loading station, in that the means for heating these preforms comprise at least one heating oven and in that said blowing means comprise at least a first and a second blowing press and control means for simultaneously actuating said presses.

According to a preferred embodiment, said presses can each be provided with two half-molds respectively associated with said control means, these control means being arranged to bring the corresponding half-molds in and out cyclically in order to alternately close and open the molding cavities defined by each pair of half-molds.

Preferably, each half-mold of the first blowing press is mechanically linked to a half-mold of the second blowing press and the control means are arranged to simultaneously actuate at least one half-mold of the first press and a second mold half mold.

Advantageously, the control means may comprise a first device arranged to actuate simultaneously a half-mold of the first press and a half-mold of the second press, these two half-molds being mechanically linked, and a second device arranged to actuate the other half-mold of the first press and the other half-mold of the second press simultaneously, these two half-molds also being mechanically linked together.

Preferably said first device arranged to simultaneously actuate a half-mold of the first press and a half-mold of the second press comprises a toggle articulated on the one hand to a movable plate in a direction perpendicular to its plane and carrying said half mold of said first press, and on the other hand to an axially movable element, and said second device arranged to simultaneously actuate the other half-mold of the first press and the other half-mold of the second press also comprises a toggle articulated on the one hand to a second movable plate in a direction perpendicular to its plane and- carrying said half-mold of the second. press, and on the other hand to said axially movable element. Said axially movable element is associated with a control member which may be a hydraulic cylinder, a pneumatic cylinder, an electric motor, or an electromagnetic device.

Each movable plate in a direction perpendicular to its plane and carrying respectively a half-mold of one and the other of said blowing presses is advantageously associated with another movable plate in a direction perpendicular to its plane and carrying respectively another half-mold of the two blowing presses. These mobile plates are mutually parallel and connected two by two by rigid rods.

According to a preferred embodiment; the machine according to the invention comprises a series of blow molding presses mounted in parallel, each of these blow molding presses comprising a first and a second half-mold, all the first half-molds of all the blow molding machines being mechanically connected between them and all the second half-molds of all these blowing presses also being mechanically connected together. It may also include control means arranged to actuate simultaneously at least all the first or all the second half-molds of the series of blow molding presses. Said control means preferably comprise a first device arranged to actuate all the first half simultaneously -moulds of blowing presses and a second device arranged to actuate simultaneously all the second half-molds of blowing presses.

According to a particularly advantageous embodiment, all the first half-molds can be mechanically connected to each other by means of at least one rigid rod and in that all the second half-molds can also be connected to each other by means of at least one minus a rigid rod.

Said first device arranged to simultaneously actuate the first half-molds preferably comprises a first toggle joint articulated on the one hand to a control member and on the other hand to a plate coupled to all of said first half-molds of the series of blowing presses and said second device arranged to actuate all the second half-molds simultaneously comprises of. preferably a second toggle joint articulated on the one hand to this same control member and on the other hand to a plate coupled to all of said second half-molds of the series of blowing presses.

The invention will be better understood with reference to the description of a preferred embodiment and to the accompanying drawing in which: FIG. 1 represents a schematic view of a machine according to the invention shown in plan, FIG. 2 represents a view schematic illustrating the control means arranged to actuate the half-molds of the blowing presses, and FIG. 3 represents an advantageous form of construction of said control means.

With reference to the figures and in particular to Figure 1, the machine 10 represented comprises a loading station 11 for preforms, a heating oven 12 (shown in broken lines) which could also be replaced by two heating ovens 13 and 14 of these preforms, a first blowing press 15, a second blowing press 16 and at least one recovery station 17 and / or 18 or for discharging the finished products after their molding.

 In this embodiment, the preform routing circuit essentially consists of rails designed to support and guide pallets A of rectangular or square shape which are equipped with support means intended to receive the preforms of thermoformable synthetic material. As shown in the figure, the pallets A appear in the loading station 11, juxtaposed by their short sides and are then pushed back alternately on the rail section 30a by a pusher 30 and on the rail section 31a by a pusher 31, then after a rotation of 904, on the sections of rails 19 and 20, juxtaposed by their large ribs. It is in this relative position that they travel through the heating ovens 13 and 14 which makes it possible to increase the length of stay of the preforms in # ovens, in a proportion which depends on the ratio of the length and width of the pallets. At the exit of the ovens, the pallets A are pushed in the direction of their length respectively by pushers 21 and 22 on the rail sections 23 and 24, then pushed back respectively by appropriate pushers 25 and 26, after a pivoting of 900, on rectilinear sections 27 and 28, pressed against each other by their short sides. The first press 15 is located on the rail section 27 and the second press 16 is located on the rail section 28. In the preferred embodiment described, the two presses are double and allow each to mold two objects in each cycle. After molding, the products are respectively discharged through stations 17 and 18. The pallets are recycled in pairs on a central rectilinear section 29 towards the loading station. This path along rectilinear sections arranged symmetrically with respect to a central axis on which the pallet recycling circuit is located is particularly advantageous because it allows a very compact construction of the machine and allows efficient integration of this machine into a line. use of molded products.

This pallet circulation scheme is most common when each pallet carries a preform and when the pallets are passed through the pallets only once in a heating oven. Various modifications or variants are possible. The ovens 13 and 14 can be replaced by a single oven 12 which partially covers the three straight sections 19, 20 and 29. In this case, each pallet passes through the oven for the first time on the central section 29 and a second time either on the lateral section 19, ie on the lateral section 20.

We can still consider another route, namely a double pass through the presses. The pallets are loaded at 11, pass through either the oven 12 (twice) or one of the ovens 13 or 14, then enter the press 15 (or 16) for the first time. They are directly recycled without being discharged, pass through either the oven 12 (twice), or one of the ovens 14 or 13f then enter the press 16 (or 15) or in the other part of the press if it is double , before being discharged and then recycled.

In addition, one can consider not loading all the pallets and making the pushers 30 and 31 intelligent, that is to say controlled so as to generate a selective transfer of the pallets to the section 30a or the section 31a. case, we can provide that all the nth pallets are transferred to the section 30a while all the other pallets are pushed onto the section 3la. In other cases, it can be envisaged that the pallets are coded and that the pushers are controlled as a function of a control signal transmitted by a pallet identification member.

In fact, the pushers 30 and 31 constitute a switch which can be controlled by external information. Such a member makes it possible to envisage an extension of the concept of this machine which may include one or more ovens, one or more loading and recovery stations and several blow molding presses which are crossed individually or in groups one or more times by preforms or other articles to be molded, which are in the raw state or in the semi-finished state '.

The presses 15 and 16 are illustrated in more detail by Figures 2 and 3. Figure 2 illustrates the operating principle of these presses. The first press 15 consists of a half-mold 40 carried by a plate 41 and of a half-mold 42 carried by a plate 43. Similarly, the second press 16 consists of a half-mold 44 carried by a plate 45 and a half-mold 46 carried by a plate 47. The plates 43 and 45 are mechanically connected by two rigid rods 48 and 49 and the two plates 41 and 47 are mechanically connected by two rigid rods 50 and 51. The rods 48 and '49 freely cross the plate 41 and the rods 50 and 51 freely cross the plate 45.

The control means for actuating said presses comprise a pneumatic or hydraulic cylinder 52 which is coupled to a sleeve 53 sliding axially and two toggles respectively 54 and 55 whose arms 54a and 54b on the one hand and 55a and 55b on the other hand have one end coupled to said sliding sleeve 53 and their other ends respectively coupled to the plate 41 and to the plate 45. As the plate 41 is mechanically linked to the plate 47 and since the plate 43 is mechanically linked to the plate 45, the axial displacement of the sleeve 53 causes a transverse displacement of the plates 41 and 43 on the one hand and 45 and 47 on the other hand, in the opposite direction, which has the effect of closing the molding cavities defined by these pairs of half-molds.

The half-molds being linked two by two, the synchronization of the two presses is perfect and does not require any delicate adjustment.

Figure 3 is a view similar to that of Figure 2, but corresponds to an actual construction and no longer to a block diagram. The half-molds each have two indentations 60. Generally, the number of impressions depends on the applications and the dimensions of the objects to be molded. The plates are mounted on four fixed rods 61 which are rigidly fixed on a support 62 (partially shown). These plates are all provided with openings 63 and guide pieces in the form of sleeves 64 which allow their controlled movement along said guide rods.

The rods 48 and 49 are fixed by means of bolts 65 to the plates 43 and 45 'and the plate is provided with openings 66 which allow the free movement of the plate 41.

 For the other press, namely press 16, the components are completely symmetrical.

The principle described above can easily be generalized by extending the number of presses and the number of preform feed channels. All the presses have two half-molds and the half-molds are linked in pairs and actuated by a single and common control member. This control member is, as before, a pneumatic or hydraulic cylinder and the mechanical connection between the plates carrying the half-molds is ensured by rigid rods.

The invention is not limited to the embodiments described, but can undergo different modifications and come in various variants obvious to those skilled in the art. The number of presses is limited only by the size of the machines. In addition, the hydraulic or pneumatic actuator for controlling these presses can easily be replaced by another actuating device such as for example an electric motor or electromagnetic means. Finally, the dimensions of the pallets can be different depending on the applications or the final dimensions of the objects produced by molding in the presses. We can even consider loading only one out of two pallets or one out of three pallets or bringing only one out of two pallets into the presses, the other being recycled for a second heating pass in the oven then in the press, or for additional treatment (heat-marking, printing, attachment of an accessory such as a handle etc.).

Claims (14)

Claims '1. Machine for manufacturing containers of the type bottles, cans, etc., of thermoformable synthetic material, according to a blowing process, comprising means for loading preforms, means for heating these preforms and means for blowing these preheated preforms, characterized in that the means for loading (11) the preforms comprise at least one loading station, in that the means for heating these preforms comprise at least one heating oven (12, 13, 14) and in that said blowing means (15, 16) comprise at least a first and a second blowing press and control means for simultaneously actuating said presses. 2. Machine according to claim 1, characterized in that said presses (15, 16) are each provided with two half-molds (40, 42; 44, # 46) respectively associated with said control means, these control means being arranged to bring cyclically close and apart the corresponding half-molds in order to alternately close and open the mold cavities (60) defined by each pair of half-molds. 3. Machine according to claim 2 characterized in that each half-mold (40, 42) of the first blowing press (15) is mechanically linked # to a half-mold (46, 44) of the second blowing press ( 16) and in that the control means are arranged to simultaneously actuate at least one half-mold of the first press and one half-mold of the second press. 4. Machine according to reve ication 3, characterized in that the control means comprise a first device arranged to simultaneously actuate a half-mold of the first press (15) and a half-mold of the second press (16), these two half -moulds being mechanically linked, and a second device arranged to simultaneously actuate the other half-mold of the first press and the other half-mold of the second press, these two half-molds being also mechanically linked together. 5. Machine according to claim 4, characterized in that said first device arranged to simultaneously actuate a half-mold of the first press and a half-mold of the second press comprises a toggle joint (54) articulated on the one hand to a plate movable (41) in a direction perpendicular to its plane and carrying said half-mold (40) of said first press (15), and on the other hand to an element (53) movable axially, and in that said second device arranged for simultaneously actuating the other half-mold of the first press and the other half-mold of the second press also comprises a toggle joint (55) articulated on the one hand to a second plate (45) movable in a direction perpendicular to its plane and carrying said half-mold (44) of the second press, and on the other hand said element (53) movable axially. 6. Machine according to claim 5, characterized in that said element (53) movable axially is associated with a control member (52). 7. Machine according to claim 6, characterized in that said control member (52) is a hydraulic cylinder, a pneumatic cylinder, an electric motor, or an electromagnetic device.  8. Machine according to claim 5, characterized in that each plate (41, 45) movable in a direction perpendicular to its plane and carrying respectively a half-mold (40, 44) of one and the other of said presses blowing is associated with another plate movable (47, 43) in a direction perpendicular to its plane and respectively carrying the other half-mold (46, 42) of the two blowing presses. 9. Machine according to claim 8, characterized in that the movable plates are mutually parallel and connected two by two by rigid rods (48, 49; 50, 51). 10. Machine according to claim 1, characterized in that it comprises a series of blowing presses. mounted in parallel, in that each of these blowing presses comprises a first and a second half-mold, in that all the first half-molds of all the blowing presses are mechanically connected together and in that all the second half-molds of all these blow molding machines are also mechanically linked together. 11. Machine according to claim 10, characterized in that it comprises control means, arranged to actuate simultaneously at least all the first or all the second half-molds of the series of blowing presses. 12. Machine according to claim 11, characterized in that said control means comprise a first device arranged to simultaneously actuate all the first half-molds of the blowing presses and a second device arranged to simultaneously actuate all the second half-molds of the presses blowing.  13. Machine according to claim 10, characterized in that all the first half-molds are mechanically connected to each other by means of at least one rigid rod and in that all the second half-molds are also connected to each other by means of '' at least one rigid rod. 14. Machine according to claim 12, characterized in that said first device comprises a first toggle joint articulated on the one hand to a control member and on the other hand to a plate coupled to all of said first half-molds of the series blowing presses and in that said second device comprises a second toggle joint articulated on the one hand to this same control member and on the other hand to a plate coupled to all of said second half-molds of the series of presses blowing.