WO2025126034A1 - An interface plate for converting an injection blow moldingmachine for plastic containers from a two-row configurationto a single-row configuration of seats for neck molds ofpreforms, or vice versa, and related converting method - Google Patents

Abstract

An interface plate (9) adapted to be fastened at a respective through-opening (3)of a rotary table (2) of a blow molding machine for plastic containers including atleast one preform injection molding station and one container blow moldingstation, wherein the rotary table (2) includes at least two through-openings (3) andis adapted to intermittently rotate so that each of the at least two through-openings(3) sequentially moves from one molding station to the other at the same time;said interface plate (9) comprising- a central through-opening (12);- a single-row support apparatus (5') configured to support a single row of neckmolds, arranged on a first surface (13) of said interface plate at said central through-opening (12);- first through holes (8') arranged at two first reciprocally opposite ends (14) of theinterface plate, suitable for fastening and centering said interface plate (9) on afirst surface (17) of the rotary table (2) at said through-opening (3).

Description

AN INTERFACE PLATE FOR CONVERTING AN INJECTION BLOW MOLDING MACHINE FOR PLASTIC CONTAINERS FROM A TWO-ROW CONFIGURATION TO A SINGLE-ROW CONFIGURATION OF SEATS FOR NECK MOLDS OF PREFORMS, OR VICE VERSA, AND RELATED CONVERTING METHOD ***********

Field of the invention

The present invention relates to an interface plate for converting an injection blow molding machine for plastic containers from a two-row configuration to a singlerow configuration of seats for neck molds of preforms, which are to be blown in the machine itself to become containers. The invention also relates to a kit for such conversion, to an injection blow molding machine and to the related converting methods from two-row to single-row configuration and vice versa.

Background art

Injection blow molding machines for plastic containers are known on the market which include at least one injection molding part for preforms and one blow molding part for containers, starting from said preforms.

Such machines comprise

- a fixed base plate;

- a rotary table, arranged below and movably supported by said fixed base plate,

- at least two support apparatuses configured to support at least one row of neck molds and fixed to a lower surface of said rotary table; wherein the rotary table is adapted to intermittently rotate about the vertical axis thereof to sequentially transport each support apparatus at least at a first station for injection-molding plastic preforms and at a second station for blow-molding containers from said preforms.

In the case of a single-row configuration of the machine, each single-row support apparatus is configured to support a single row of neck molds at a respective through-opening of said rotary table so that the neck molds are accessible.

In the case of a two-row configuration of the machine, each two-row support apparatus is configured to support two parallel rows of neck molds at a respective through-opening of said rotary table so that the neck molds are accessible. Unfortunately, current injection blow molding machines do not allow a change of configuration of the machine from two-row to single-row, or vice versa.

Therefore, the need is felt to create an innovative solution which allows overcoming the aforesaid drawbacks.

Summary of the invention

It is the main object of the present invention to provide an interface plate, applicable to a rotary table of an injection blow molding machine, which allows a simple and quick conversion of the machine from a two-row configuration to a single-row configuration of seats for neck molds.

It is another object of the invention to provide a kit for performing the aforesaid simple and quick conversion of the machine from a two-row configuration to a single-row configuration.

It is a further object of the invention to provide an injection blow molding machine configured for the aforesaid conversion.

It is another object of the invention to provide a method for converting the aforesaid injection blow molding machine from a two-row configuration to a singlerow configuration of seats for neck molds, and vice versa.

The present invention, therefore, offers to achieve at least one of the objects discussed above by providing an interface plate adapted to be fastened at a respective through-opening of a rotary table of an injection blow molding machine for plastic containers including at least one preform injection molding station and one container blow molding station, wherein the rotary table includes at least two through-openings and it is adapted to intermittently rotate so that each of the at least two through-openings moves sequentially from one station to the other at the same time; wherein said interface plate comprises

- a central through-opening;

- a single-row support apparatus configured to support a single row of neck molds and arranged on a first surface of said interface plate at said central through- opening;

- first through holes arranged at two first reciprocally opposite ends of the interface plate and suitable for fastening and centering said interface plate on a first surface of the rotary table at said through-opening. A second aspect of the present invention relates to a kit for converting said injection blow molding machine from a two-row configuration to a single-row configuration of seats for neck molds of preforms, or vice versa, said machine comprising a rotary table provided along the periphery thereof with at least two through-openings; wherein said rotary table is provided, on a first surface thereof, at two reciprocally opposite ends of each through-opening, with respective side guides configured to laterally insert or extract, parallel to said first surface, a two-row support apparatus configured to support two parallel rows of neck molds at said through-opening; wherein said rotary table is provided with respective second through holes, at two further reciprocally opposite ends of each through-opening which are transverse to the aforesaid ends; said kit comprising:

- a number of interface plates, as described above, equal to the number of through-openings of the rotary table;

- removable fastening and centering means for removably fastening and centering each interface plate at the respective through-opening, by means of cooperation with said first through holes and said second through holes.

A third aspect of the present invention relates to an injection blow molding machine for plastic containers, including at least one preform injection molding station and one container blow molding station, the machine further comprising

- a rotary table provided along the periphery thereof with at least two through- openings and adapted to intermittently rotate so that each of the at least two through-openings moves sequentially from one station to the other at the same time;

- at least two interface plates, removably fastened to a lower surface of said rotary table, each interface plate being fastened at a respective through-opening of said rotary table; wherein each interface plate comprises

- a central through-opening;

- a single-row support apparatus configured to support a single row of neck molds and arranged on a lower surface of said interface plate at said central through-opening; - first through holes arranged at two first opposite ends of the interface plate; wherein said rotary table is provided, on said lower surface thereof, at two, reciprocally opposite, ends of each through-opening, with respective side guides configured for a possible lateral insertion, parallel to said lower surface, of a two- row support apparatus replacing a respective interface plate with a single-row support apparatus, said two-row support apparatus being configured to support two parallel rows of neck molds at said through-opening; wherein said rotary table is provided with respective second through holes, at two further, reciprocally opposite, ends of each through-opening which are transverse to the aforesaid ends; wherein removable fastening and centering means are provided that removably fasten and center each interface plate at the respective through-opening, by means of cooperation with said first through holes and said second through holes; whereby when the rotary table intermittently rotates, each single-row support apparatus, or each two-row support apparatus replacing the respective single-row support apparatus, moves sequentially from one molding station to the other at the same time.

A fourth aspect of the present invention relates to a method for converting the aforesaid molding machine from a two-row configuration to a single-row configuration of seats for neck molds of said preforms, the method comprising the following steps:

- providing a two-row support apparatus supporting two rows of neck molds at each through-opening of the rotary table;

- laterally extracting each two-row support apparatus, sliding it on the respective side guides;

- removably fastening an interface plate to the lower surface of said rotary table at each through-opening so that each single-row support apparatus, configured to support a single row of neck molds, is at a respective through-opening.

A fifth aspect of the present invention relates to a method for converting the aforesaid molding machine from a single-row configuration to a two-row configuration of seats for neck molds of said preforms, the method comprising the following steps:

- providing an interface plate removably fastened to the lower surface of said rotary table at a respective through-opening so that each single-row support apparatus, configured to support a single row of neck molds, is at said respective through-opening;

- removing each interface plate at each through-opening;

- laterally inserting, at each through-opening, a two-row support apparatus supporting two rows of neck molds, sliding it on the respective side guides.

The dependent claims describe preferred embodiments of the invention.

Brief description of the Figures

Further features and advantages of the invention will become more apparent in the light of the detailed description of a preferred but not exclusive embodiment of a technical solution partially illustrated, by way of non-limiting example, with reference to the accompanying drawing tables, in which:

Figure 1 shows a bottom perspective view of an interface plate according to the invention;

Figure 2 shows a top perspective view of the interface plate of Figure 1 ;

Figure 3 shows a top perspective view of a rotary table provided with two-row support apparatuses, associated with a fixed base plate of a molding machine;

Figure 4 shows a top perspective view of a rotary table provided with interface plates according to the invention, with single-row support apparatus, and associated with a fixed base plate of a molding machine;

Figure 5 shows a bottom perspective view of the rotary table of Figure 3;

Figure 6 shows a bottom perspective view of the rotary table of Figure 4;

Figure 7 shows a bottom plan view of the rotary table of Figure 3;

Figure 8 shows a bottom plan view of the rotary table of Figure 4;

Figure 9 shows a top perspective view of the rotary table alone;

Figure 10 shows a top perspective view of a plurality of interface plates according to the invention, to be associated with the rotary table of Figure 9;

Figure 11 shows a bottom perspective view of the rotary table of Figure 9;

Figure 12 shows a bottom perspective view of a plurality of interface plates according to the invention, to be associated with the rotary table of Figure 9;

Figures 13a and 13b show a bottom perspective view of a single-row support apparatus of neck molds in the normally closed position and the open position, respectively;

Figures 13c and 13d show a top perspective view of said single-row support apparatus of neck molds in the normally closed position and the open position, respectively.

The same reference numerals in the Figures identify the same elements or components.

Detailed description of preferred embodiments of the invention

With reference to the Figures, parts of an injection blow molding machine are shown for making containers made of thermoplastic material such as PET, PEN or other suitable material, as well as mixtures thereof.

The injection blow molding machine for plastic containers, only partially shown, in a two-row configuration thereof (Figures 3, 5, 7) comprises:

- a fixed base plate 1 ;

- a rotary table 2, placed below and movably supported by the fixed base plate 1 , and provided along the periphery thereof with at least two through-openings 3 (Figures 9, 11 );

- at least two two-row support apparatuses 5 configured to each support two rows of neck molds 22 of a plastic container, the support apparatuses 5 being removably fastened to the lower surface 17 of the rotary table 2.

Figures 5 and 7, for simplicity, show only one neck mold 22 in each of the two rows of seats 24 for neck molds.

In particular, each two-row support apparatus 5 is fastened at a respective through-opening 3 of the rotary table 2.

As shown in Figure 11 , the rotary table 2 is provided on the lower surface 17 thereof, at two reciprocally opposite ends 18 of each through-opening 3, with respective side guides 4 configured to laterally insert or extract, parallel to said lower surface 17, a corresponding two-row support apparatus 5.

Each two-row support apparatus 5 comprises (Figure 7) two pairs of longitudinal split plates 6, 6’, each pair of plates 6, 6’ being adjacent to the other pair of plates 6, 6’ along a longitudinal axis X. In turn, each pair of plates comprises two plates 6, 6’ adjacent to each other and separable from each other transversely to said longitudinal axis X, and kept adjacent in a normally closed state by means of elastic means (not shown) defining a respective row of seats for respective neck molds.

In the normally closed state, the position of the two pairs of plates 6, 6' is shown in Figure 7. When the two-row support apparatus 5 passes from the normally closed position to an open position of the plates 6, 6' (not shown), in a first moment a pair of plates 6, 6' is moved away from the other pair adjacent thereto transversely to said longitudinal axis X, and subsequently the plates 6, 6' of each pair are moved away from each other, again transversely to said longitudinal axis X.

Therefore, if a force for reciprocally separating or opening the plates 6, 6' of each pair transversely, preferably orthogonally, to said longitudinal axis X is not applied, the plates 6, 6' of each pair are adjacent to each other, and therefore are in a closed state. For example, this force of separation can be applied to the respective two ends of each pair of plates 6, 6' by means of wedges which are inserted between two rollers (not shown), one roller for each plate end.

The elastic means, not described herein as they are known per se, comprise springs arranged on the outer longitudinal edges of the plates 6, 6' of the two pairs of plates, said springs being preferably arranged inside respective recesses of said outer longitudinal edges.

The two plates 6, 6' of each pair of plates, preferably rectangular-shaped, are provided, along an inner longitudinal edge, with a respective plurality of side recesses, that are substantially semi-circular and positioned so that, when the plates 6, 6’ of a pair of plates are in the normally closed state, the side recesses of the plates 6, 6’ of the pair of plates are two-by-two adjacent to each other defining corresponding seats 24, for example substantially circular seats, for accommodating a respective neck mold 22 (Figure 7).

The neck molds 22 each comprise a pair of split molds, each split mold being houseable in a side recess of a respective plate 6, 6’, whereby, when the plates 6, 6’ of each pair of plates are in the normally closed state, the two split molds are adjacent. In particular, at the two reciprocally opposite ends 18 of each through-opening 3 (Figure 11 ), a pair of side guides 4 is provided, transverse to the longitudinal axis X and fastened to the lower surface 17 of the rotary table 2; each side guide 4 being adapted to support from below, by means of a shoulder made thereon, a respective end of the set of the two pairs of longitudinal plates 6, 6' of the two-row support apparatus 5.

The side guides 4 are provided with a respective locking system 21 to lock to the pair of side guides 4, or unlock from the pair of side guides 4, the two pairs of plates 6, 6' so that in an unlocked position the two pairs of plates 6, 6' can be extracted transversely to the longitudinal axis X by sliding on the side guides 4, in particular by sliding on the horizontal surface of the shoulder provided on said side guides 4.

The plates 6, 6’ of each pair of plates, equal to each other, preferably are in the shape of a rectangular parallelepiped, with the longitudinal extension (along the axis X) being greater than both the width and the thickness of the plate.

The rotary table 2, for example in the shape of a disk, is adapted to intermittently rotate to sequentially move each of the at least two through-openings 3, and therefore each two-row support apparatus 5, from one workstation to another at the same time.

In the case of two two-row support apparatuses 5, the rotary table 2 intermittently rotates to move a first support apparatus 5 from a plastic preform injection molding station to a blow molding station for containers, starting from said preforms, and, at the same time, to move a second support apparatus 5 from said blow molding station to said injection molding station.

Four two-row support apparatuses 5 are provided in the example of Figures 3, 5, 7. In this case, the rotary table 2 intermittently rotates to sequentially move each of the four through-openings 3, and therefore each of the four two-row support apparatuses 5, from one workstation to another, at the same time.

In particular, each two-row support apparatus 5 is moved in sequence, from a first station for preform injection molding to a second station for adjusting the temperature of the preforms; from said second station to a third station for container blow molding; from said third station to a fourth station for container ejection; and from said fourth station to said first station. In this case, the two-row support apparatuses 5, in particular the centres of gravity of said apparatuses, are arranged on the rotary table 2 at an angular distance of 90° from one another.

The different workstations are not herein described because they are of the known type.

Advantageously, to convert the aforesaid machine from the two-row configuration to a single-row configuration, the solution of the invention provides for the use of a kit comprising:

- a number of interface plates 9 equal to the number of through-openings 3 of the rotary table 2; and

- removable fastening and centering means for removably fastening and centering each interface plate 9 at the respective through-opening 3.

Each interface plate 9, adapted to be fastened at a respective through-opening 3 of the rotary table 2 in place of a two-row support apparatus 5, comprises (Figures 1 and 2):

- a central through-opening 12;

- a single-row support apparatus 5’ configured to support a single row of neck molds and arranged on a lower surface 13 of the interface plate 9 at said central through-opening 12;

- first through holes 8’, arranged at two, reciprocally opposite, first ends 14 of the interface plate 9, and suitable for fastening and centering said interface plate 9 on the lower surface 17 of the rotary table 2.

Advantageously, the rotary table 2 is provided, at two further ends 19 of each through-opening 3, reciprocally opposite and transverse to the ends 18, with respective second through holes 8, whereby said removable fastening and centering means removably fasten and center each interface plate 9 at the respective through-opening 3, by means of a cooperation with said first through holes 8' and said second through holes 8.

In a preferred variant (Figures 9 and 11), the rotary table 2 is provided on the lower surface 17 thereof, at said two further ends 19 of each through-opening 3, with respective longitudinal recesses 11 in which said second through holes 8 are provided. Preferably, said removable fastening and centering means comprise fastening screws and collar screws 10 to respectively fasten and center each interface plate 9 with respect to the corresponding through-opening 3, passing through both the first through holes 8’ and the second through holes 8.

In particular, each fastening and centering means passes through a respective first through hole 8’ of the interface plate 9 and a corresponding second through hole 8 of the rotary table 2.

In the variant of Figures 1-2, 10 and 12, for example, there are shown only two collar screws 10 at the two through holes 8’ at two opposite edges of the interface plate 9, preferably in the shape of a rectangular parallelepiped, with the longitudinal extension (along the axis X’) greater than both the width and the thickness of the plate 9. At the remaining through holes 8’, the insertion of simple fastening screws is provided. This configuration ensures an optimal centering of the interface plate 9.

Each single-row support apparatus 5’ (Figure 1) comprises a single pair of longitudinal split plates 16, 16’ kept adjacent to each other along a longitudinal axis X’ in a normally closed state by means of elastic means 7’, defining a single row of seats 24 for respective neck molds. The two plates 16, 16’ are separable from each other transversely to said longitudinal axis X’.

This means that if a force for separating or opening the plates 16, 16’ to each other transversely, preferably orthogonally, to axis X’ is not applied, the plates 16, 16’ are adjacent to each other along axis X’, and therefore are in a closed state.

For example, this force of separation can be applied to the respective two ends of the pair of plates by means of a corresponding wedge (not shown) which is inserted between two rollers 25, one roller 25 being provided at each end of the plate 16, 16’.

The elastic means 7’, herein not described because inherently known, comprise springs arranged on the outer longitudinal edges of each plate 16, 16’.

As shown in Figures 13a-13d, each plate 16, 16’, preferably rectangular-shaped, is provided, along an inner longitudinal edge, with a respective plurality of substantially semicircular side recesses, positioned so that, when the plates 16, 16’ of the pair of plates are in the normally closed state, the side recesses of the plates 16, 16’ are two-by-two adjacent to each other along said longitudinal axis X’ defining corresponding seats 24, for example substantially circular, to house a respective neck mold 22.

The neck molds 22 each comprise a pair of split molds 23, each split mold 23 being houseable in a side recess of a respective plate 16, 16’, whereby, when the plates 16, 16’ of said pair of plates are in the normally closed state, the two split molds 23 are reciprocally adjacent along the axis X’.

The central through-opening 12 of each interface plate 9 has a substantially longitudinal shape along the axis X' (Figure 2).

Preferably, two side guides 20 (Figure 1) are provided on the lower surface 13 of each interface plate 9 at two second ends 15 of said interface plate, opposite to each other and transverse to the first ends 14.

These side guides 20 are configured to laterally insert or extract, parallel to the interface plate, in particular parallel to the lower surface 13 thereof, the respective single-row support apparatus 5’.

In particular, a pair of side guides 20 is provided transverse to the longitudinal axis X’ and fastened to the lower surface 13 of each interface plate 9; each side guide 20 being adapted to support from below, by means of a shoulder 26 made thereon, a respective end of the pair of longitudinal plates 16, 16’.

The side guides 20 are provided with a respective locking system (not shown) to lock or unlock the pair of plates 16, 16' to/from the pair of side guides 20, so that in an unlocked position, the pair of plates 16, 16' can be extracted transversely to their longitudinal axis X' by sliding on the side guides 20, in particular by sliding on the horizontal surface of the shoulder 26 provided on said side guides.

The plates 16, 16’ of each pair of plates, equal to each other, preferably are in the shape of a rectangular parallelepiped, with the longitudinal extension (along the axis X’) being greater than both the width and the thickness of the plate.

Described below is a method according to the invention for converting the aforesaid molding machine from a two-row configuration to a single-row configuration of seats for neck molds of preforms, the method comprising the following steps:

- providing a two-row support apparatus 5 supporting two rows of neck molds at each through-opening 3 of the rotary table 2 so that the neck molds are accessible;

- laterally extracting each two-row support apparatus 5, said two-row support apparatus sliding on the respective side guides 4;

- removably fastening an interface plate 9 to the lower surface 17 of the rotary table 2 at each through-opening 3 so that each single-row support apparatus 5’, configured to support a single row of neck molds, is at a respective through- opening 3 so that the neck molds are accessible.

Conversely, the method according to the invention for converting the aforesaid molding machine from a single-row configuration to a two-row configuration of seats for neck molds of preforms comprises the following steps:

- providing an interface plate 9 removably fastened to the lower surface 17 of the rotary table 2 at each through-opening 3 so that each single-row support apparatus 5’, configured to support a single row of neck molds, is at said respective through-opening 3 so that the neck molds are accessible;

- removing each interface plate 9 at each through-opening 3;

- laterally inserting, at each through-opening 3, a two-row support apparatus 5 supporting two rows of neck molds, said two-row support apparatus sliding on the respective side guides 4.

Claims

1 . An interface plate (9) adapted to be fastened at a respective through-opening (3) of a rotary table (2) of a plastic container blow molding machine at least including one preform injection molding station and one container blow molding station, wherein the rotary table (2) includes at least two through-openings (3) and it is adapted to intermittently rotate so that each of the at least two through- openings (3) sequentially moves from one molding station to the other at the same time; said interface plate (9) comprising

- a central through-opening (12);

- a single-row support apparatus (5’) configured to support a single row of neck molds and arranged on a first surface or lower surface (13) of said interface plate at said central through-opening (12);

- first through holes (8’) arranged at two first, reciprocally opposite, ends (14) of the interface plate and suitable for fastening and centering said interface plate (9) on a first surface (17) of the rotary table (2) at said through-opening (3).

2. An interface plate according to claim 1 , wherein side guides (20) are provided on said first surface (13), at two second ends (15) of said interface plate, opposite to each other and transverse to the first ends (14); said side guides (20) being configured to laterally insert or extract, parallel to said interface plate, said singlerow support apparatus (5’).

3. A kit for converting a blow molding machine for blow molding plastic containers, including at least one preform injection molding station and one container blow molding station, from a two-row configuration to a single-row configuration of seats for neck molds of said preforms, or vice versa, said machine comprising a rotary table (2) provided, along the periphery thereof, with at least two through-openings (3); wherein said rotary table (2) is provided, on a first surface (17) thereof, at two reciprocally opposite ends (18) of each through-opening (3), with respective side guides (4) configured to laterally insert or extract, parallel to said first surface (17), a two-row support apparatus (5) configured to support two parallel rows of neck molds at said through-opening (3); wherein said rotary table (2) is provided with respective second through holes (8), at two further, reciprocally opposite, ends (19) of each through-opening (3) that are transverse to the ends (18); said kit comprising:

- a number of interface plates (9), according to claim 1 , equal to the number of through-openings (3) of the rotary table (2);

- removable fastening and centering means for removably fastening and centering each interface plate (9) at the respective through-opening (3), by means of cooperation with said first through holes (8’) and said second through holes (8).

4. A kit according to claim 3, wherein said removable fastening and centering means comprise fastening screws and collar screws (10) for fastening and centering each interface plate (9) with respect to the corresponding through- opening (3), respectively.

5. An injection and blow molding machine for plastic containers, at least including one preform injection molding station and one container blow molding station, the machine further comprising

- a rotary table (2) provided along the periphery thereof with at least two through- openings (3) and adapted to intermittently rotate so that each of the at least two through-openings (3) moves sequentially from one molding station to the other at the same time;

- at least two interface plates (9) according to claim 1 , removably fastened to a lower surface (17) of said rotary table (2), each interface plate (9) being fastened at a respective through-opening (3) of said rotary table (2); wherein said rotary table (2) is provided, on said lower surface (17) thereof, at two reciprocally opposite ends (18) of each through-opening (3), with respective side guides (4) configured for a possible lateral insertion, parallel to said lower surface (17), of a two-row support apparatus (5) replacing a respective interface plate (9) with a single-row support apparatus (5’), said two-row support apparatus (5) being configured to support two parallel rows of neck molds at said through-opening (3); wherein said rotary table (2) is provided with respective second through holes (8), at two further, reciprocally opposite, ends (19) of each through-opening (3) that are transverse to the ends (18); wherein removable fastening and centering means are provided which removably fasten and center each interface plate (9) at the respective through-opening (3), by means of cooperation with said first through holes (8’) and said second through holes (8); whereby when the rotary table (2) intermittently rotates, each single-row support apparatus (5’), or each two-row support apparatus (5) replacing the respective single-row support apparatus (5’), moves sequentially from one molding station to the other at the same time.

6. A machine according to claim 5, wherein said rotary table (2) is provided with respective recesses (11 ) on said lower surface (17), at said two further ends (19) of each through-opening (3); and wherein said second through holes (8) are provided in said recesses (11 ).

7. A machine according to claim 5 or 6, wherein each single-row support apparatus (5’) comprises a single pair of plates (16, 16’) which are adjacent to each other along a longitudinal axis (X’) and separable from each other transversely to said longitudinal axis (X’), and kept adjacent in a usually closed state, by means of elastic means (7’), defining a single row of seats for respective neck molds.

8. A machine according to claim 7, wherein each plate (16, 16’) is provided with a respective plurality of recesses positioned so that when the plates (16, 16’) of the pair of plates are in the usually closed state, the recesses of the plates (16, 16’) of the pair of plates are adjacent to one another along said longitudinal axis (X’), defining a plurality of seats for respective neck molds (22) each comprising a pair of split molds (23), each split mold (23) being houseable in a recess of a respective plate (16, 16’).

9. A method for converting a molding machine according to claim 5, from a two- row configuration to a single-row configuration of seats for neck molds of said preforms, the method comprising the following steps:

- providing a two-row support apparatus (5) supporting two rows of neck molds at each through-opening (3) of the rotary table (2);

- laterally extracting each two-row support apparatus (5), said two-row support apparatus sliding on the respective side guides (4); - removably fastening an interface plate (9) to the lower surface (17) of said rotary table (2) at each through-opening (3) so that each single-row support apparatus (5’), configured to support a single row of neck molds, is at a respective through- opening (3).

10. A method for converting a molding machine according to claim 5, from a single-row configuration to a two-row configuration of seats for neck molds of said preforms, the method comprising the following steps:

- providing an interface plate (9) removably fastened to the lower surface (17) of said rotary table (2) at each through-opening (3) so that each single-row support apparatus (5’), configured to support a single row of neck molds, is at said respective through-opening (3) of the rotary table (2);

- removing each interface plate (9) at each through-opening (3);

- laterally inserting, at each through-opening (3), a two-row support apparatus (5) supporting two rows of neck molds, said two-row support apparatus sliding on the respective side guides (4).