CN214294404U

CN214294404U - Blow mold structure

Info

Publication number: CN214294404U
Application number: CN202023201693.0U
Authority: CN
Inventors: 陈艺力; 高寿; 关红民
Original assignee: Foshan Gongzheng Packaging Equipment Technology Co ltd
Current assignee: Foshan Gongzheng Packaging Equipment Technology Co ltd
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2021-09-28
Anticipated expiration: 2030-12-25

Abstract

The utility model discloses a blow mould structure, which comprises at least one group of blow mould components; the blow mold assembly comprises a blow mold, a first fixing plate, a second fixing plate, two first bearing plates, two second bearing plates and a third fixing plate, and the supporting mechanism comprises a fixing seat and a guide structure; the fixed seat is positioned below the third fixed plate and is fixedly arranged on the first fixed plate; the guide structure comprises a shaft sleeve and a guide shaft, and the shaft sleeve is fixedly arranged on the bottom surface of the third fixing plate; the lower end of the guide shaft is arranged on the fixed seat, and the upper end of the guide shaft is inserted in the shaft sleeve; the jacking mechanism comprises a transverse push plate, a plurality of vertical jacking rods and a plurality of vertical connectors, wherein the transverse push plate is positioned below the fixed seat; the upper end of the vertical jacking rod is a free end, and the lower end of the vertical jacking rod is fixedly connected with the top surface of the transverse push plate; the upper end of the vertical connector is fixedly connected with the bottom surface of the transverse push plate, and the lower end of the vertical connector is used for being connected with the output end of the power mechanism. The utility model has the characteristics of easy dismounting, atress are even and long service life.

Description

Blow mold structure

Technical Field

The utility model relates to a mould, concretely relates to blow mould structure of blow molding machine.

Background

The rotary transfer blow molding machine includes an injection molding step, a temperature adjusting step, a blow molding step, and a taking-out step. In a rotary transfer type blow molding machine, an injection molding station, a temperature adjusting station, a blow molding station, and a take-out station are provided in each of 4 sections of a transfer area of 360 ° in one revolution. Each station is provided with 4 transfer plates which are intermittently and rotationally conveyed. The transfer plate is intermittently transferred to the injection molding station, the temperature adjusting station, the blow molding station, and the take-out station in this order. The blow-molding station arranged downstream of the tempering station in the conveying direction has two rows of blow molds. In the blow molding station, a plurality of preforms are blow molded into a plurality of containers in two blow molds that are clamped together, each blow mold having a pair of blow cavity split molds and a male mold.

In the prior art, patent application No. CN201080062534.7 discloses a blow mold unit mounted on a base of a blow molding machine, which has a blow mold including 1 st and 2 nd blow cavity split molds and a plurality of male bottom molds. The blow mold unit further has: the 1 st fixed plate is used for fixing the 1 st blow molding cavity combined die; the 2 nd fixed plate is used for fixing the 2 nd blow molding cavity combined die; a plurality of 1 st pressure bearing plates which are configured at one side of each two side surfaces of the 1 st blow molding cavity combination die and the 2 nd blow molding cavity combination die and are respectively fixed on the 1 st fixing plate and the 2 nd fixing plate; a 3 rd fixing plate disposed between the 1 st and 2 nd fixing plates and fixing the plurality of raised bottom molds to the 1 st surface; a plurality of shaft parts hanging from the No. 2 surface of the No. 3 fixing plate, and the lower ends of the shaft parts are free end parts; and a plurality of 2 nd bearing plates fixed to the 1 st and 2 nd fixing plates below the 3 rd fixing plate, respectively. The blow mold unit of this structure has the following problems: a plurality of shaft portions are provided, and hang down from the 2 nd surface of the 3 rd fixing plate, and the lower end is a free end portion, and when a drive lever is raised by a bottom die raising and lowering portion (raising and lowering device), four shaft portions are pushed up via the 1 st and 2 nd connecting portions, and a plurality of convex bottom dies fixed to the 3 rd fixing plate can be closed. The four shaft portions are abutted against the upper ends of the four drive levers of the raised bottom die lifting portion (lifting device), and can bear pressure when the raised bottom die is closed. The shaft part has a fixed end part and a free end part which are fixed on the 3 rd fixing plate, so that the shaft part has the defect of troublesome disassembly and assembly, and the shaft part can be stressed by the pressure of the convex bottom die after the die assembly and the die stripping, thereby reducing the service life. In addition, the free ends of the plurality of shaft portions are driven by the lifting devices, and if one lifting device fails, the stress is uneven.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model aims to provide a blow mold structure which has the characteristics of convenient disassembly and assembly, uniform stress and long service life.

The purpose of the utility model is realized by adopting the following technical scheme:

a blow mold structure comprising at least one set of blow mold assemblies; the blow mold assembly comprises:

the blow molding die comprises a first blow molding half die, a second blow molding half die and a plurality of convex bottom dies, and parting surfaces of the first blow molding half die and the second blow molding half die are abutted with each other to form a plurality of cavities; the number of the convex bottom dies is consistent with that of the cavities and is positioned below the cavities;

a first holding plate for holding a first blow-molding half-mold;

a second holding plate for holding a second blow mold half;

the two first bearing plates are respectively arranged on one side of two side surfaces of the first blow-molding half die and are fixed on the first fixing plate;

two second bearing plates which are respectively arranged on one side of two side surfaces of the second blow-molding half mold and are fixed on the second fixing plate;

the third fixing plate is arranged between the first fixing plate and the second fixing plate, and the plurality of convex bottom dies are arranged on the top surface of the third fixing plate;

characterized in that the blow mold assembly further comprises:

the supporting mechanism comprises a fixed seat and a guide structure; the fixed seat is positioned below the third fixed plate and is fixedly arranged on the first fixed plate; the guide structure comprises a shaft sleeve and a guide shaft, and the shaft sleeve is fixedly arranged on the bottom surface of the third fixing plate; the lower end of the guide shaft is arranged on the fixed seat, and the upper end of the guide shaft is inserted into the shaft sleeve;

the jacking mechanism comprises a transverse push plate, a plurality of vertical jacking rods and a plurality of vertical connectors, wherein the transverse push plate is positioned below the fixed seat; the upper end of the vertical jacking rod is a free end, and the lower end of the vertical jacking rod is fixedly connected with the top surface of the transverse push plate; the upper end of the vertical connector is fixedly connected with the bottom surface of the transverse push plate, and the lower end of the vertical connector is used for being connected with the output end of the power mechanism.

In an optional embodiment, the supporting mechanism further includes a buffer structure, and the buffer structure is connected between the third fixing plate and the fixing seat.

In an optional embodiment, the buffer structure comprises a first connecting piece, a second connecting piece, a connecting shaft and a spring; the first connecting piece comprises two first vertical connecting plates and a first transverse connecting plate connected to the bottoms of the two first vertical connecting plates, the upper ends of the two vertical connecting plates are fixedly connected with the third fixing plate respectively, and the first transverse connecting plate is provided with a through hole; the second connecting piece comprises a second vertical connecting plate and a second transverse connecting plate connected to the top of the second vertical connecting plate, the bottom of the second vertical connecting plate is fixedly connected with the fixed seat, and the free end of the second transverse connecting plate extends into the space between the two first vertical connecting plates; one end of the connecting shaft is fixedly arranged on the free end of the second transverse connecting plate, and the other end of the connecting shaft is inserted into the through hole; the spring is sleeved on the connecting shaft, the upper end of the spring is abutted against the free end of the second transverse connecting plate, and the lower end of the spring is abutted against the first transverse connecting plate.

In an optional implementation mode, the number of the buffer structures is two, and the buffer structures are symmetrically distributed at the left end and the right end of the fixed seat; the number of the guide structures is two, and the guide structures are symmetrically distributed at the left end and the right end of the fixed seat and are positioned at the inner side of the buffer structure.

In an alternative embodiment, a positioning hole is formed in the bottom surface of the third fixing plate, and the top of the guide shaft can penetrate through the shaft sleeve to be inserted into the positioning hole.

In an alternative embodiment, the number of the vertical lifting rods is more than two.

In an optional implementation mode, be provided with on the fixing base and supply the groove of dodging that vertical jacking rod passed, the quantity of vertical jacking rod is three, two of them vertical jacking rod symmetric distribution in both ends about horizontal push pedal, the remaining one vertical jacking rod is located the middle part of horizontal push pedal, its free end runs through dodge the groove.

In an optional embodiment, the first fixing plate, the first blow-molding half mold and the two first bearing plates are of an integrally formed structure, and the second fixing plate, the second blow-molding half mold and the two second bearing plates are of an integrally formed structure.

In an alternative embodiment, the number of the blow mold assemblies is two, and the first fixing plates of the two sets of blow mold assemblies are oppositely arranged.

In an alternative embodiment, the blow molding machine further comprises two fixing blocks for fixing to a base of the blow molding machine, the two fixing blocks are respectively fixed to one side of two side surfaces of the first blow molding half mold, and each fixing block is respectively and fixedly connected to the two first bearing plates located on the same side.

Compared with the prior art, the beneficial effects of the utility model reside in that:

the supporting mechanism of the blow mould structure of the utility model comprises a fixed seat and a guiding structure; the jacking mechanism comprises a transverse push plate, a vertical jacking rod and a vertical connector; the upper end of the vertical jacking rod is a free end, and the lower end of the vertical jacking rod is fixedly connected with the top surface of the transverse push plate; in the die assembly process, a plurality of power mechanisms drive a plurality of vertical connectors to ascend, the plurality of vertical connectors drive a transverse push plate and a vertical lifting rod to ascend, and after the vertical lifting rod abuts against the bottom surface of a third fixing plate, the third fixing plate, a convex bottom die and a shaft sleeve are driven to ascend until the convex bottom die and a cavity are assembled; in the demolding process, a plurality of vertical connectors are driven by a plurality of power mechanisms to descend, the plurality of vertical connectors drive the transverse push plates and the vertical jacking rods to descend, the third fixing plate, the convex bottom die and the shaft sleeve descend along the action of gravity, when the shaft sleeve slides along the guide shaft and descends to be in contact with the top surface of the fixing seat, the third fixing plate is supported by the fixing seat, demolding is completed, and the vertical jacking rods can continue to descend to be separated from the bottom surface of the third fixing plate. In the die assembly process, as the plurality of power mechanisms drive the vertical jacking rods to ascend through the transverse push plate, when a certain power mechanism breaks down, the uniform stress of the vertical jacking rods can be ensured; after demoulding, the vertical jacking rod is separated from the bottom surface of the third fixing plate, so that the novel mould has the advantages of convenience in disassembly and assembly and long service life; therefore, the novel bearing has the characteristics of convenience in disassembly and assembly, uniform stress and long service life.

Drawings

FIG. 1 is an exploded view of a blow mold structure according to a first embodiment;

FIG. 2 is a perspective view of a neck mold structure according to the first embodiment;

FIG. 3 is a schematic structural view of a second blow mold half, a second stationary plate, and a second bearing plate according to the first embodiment;

FIG. 4 is a schematic structural diagram of a supporting mechanism and a jacking mechanism according to the first embodiment;

FIG. 5 is a schematic cross-sectional view of a blow mold structure according to a first embodiment;

fig. 6 is a perspective view of a blow mold structure according to a second embodiment.

In the figure: 11. a first blow-molding half-mold; 12. a second blow mold half; 13. a convex bottom die; 20. a first fixing plate; 30. a second fixing plate; 40. a first bearing plate; 50. a second bearing plate; 60. a third fixing plate; 61. positioning holes; 70. a support mechanism; 71. a fixed seat; 711. an avoidance groove; 72. a guide structure; 721. a shaft sleeve; 722. a guide shaft; 73. a buffer structure; 731. a first connecting member; 7311. a first vertical connecting plate; 7312. a first transverse connecting plate; 732. a second connecting member; 7321. a second vertical connecting plate; 7322. a second transverse connecting plate; 733. a connecting shaft; 734. a spring; 80. a jacking mechanism; 81. a transverse push plate; 82. a vertical jacking rod; 83. a vertical connector; 90. and (5) fixing blocks.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that the embodiments or technical features described below can be arbitrarily combined to form a new embodiment without conflict. Except as specifically noted, the materials and equipment used in this example are commercially available. Examples of embodiments are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. In the description of the present application, "a plurality" means two or more unless specifically stated otherwise.

In the description of the present application, it should be noted that unless otherwise specifically stated or limited, the terms "connected," "communicating," and "connected" are to be construed broadly, e.g., as meaning a fixed connection, a connection through an intervening medium, a connection between two elements, or an interaction between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

The terms "first," "second," and the like in the description and in the claims of the present application and in the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The first embodiment is as follows:

referring to fig. 1-5, a blow mold structure includes a set of blow mold assemblies; the blow mold assembly includes:

the blow mold comprises a first blow mold half 11, a second blow mold half 12 and a plurality of convex bottom molds 13, and parting surfaces of the first blow mold half 11 and the second blow mold half 12 are abutted with each other to form a plurality of cavities; the number of the convex bottom dies 13 is consistent with that of the cavities and is positioned below the cavities;

a first holding plate 20 for holding the first blow-moulding half-mould 11;

a second holding plate 30 for holding the second blow mold half 12;

two first pressure bearing plates 40, which are respectively disposed at one side of both side surfaces of the first blow-molding mold half 11, and which are fixed to the first fixing plate 20;

two second pressure-bearing plates 50, which are respectively provided on one side of both side surfaces of the second blow mold half 12, and which are fixed to the second fixing plate 30;

a third fixing plate 60 disposed between the first fixing plate 20 and the second fixing plate 30, the plurality of male bottom molds 13 being disposed on a top surface of the third fixing plate 60;

the supporting mechanism 70, the supporting mechanism 70 includes the permanent seat 71, the guide structure 72; the fixing base 71 is located below the third fixing plate 60 and is fixedly mounted on the first fixing plate 20; the guide structure 72 includes a shaft sleeve 721 and a guide shaft 722, the shaft sleeve 721 is fixedly installed on the bottom surface of the third fixing plate 60; the lower end of the guide shaft 722 is arranged on the fixed seat 71, and the upper end thereof is inserted into the shaft sleeve 721;

the jacking mechanism 80 comprises a transverse push plate 81 positioned below the fixed seat 71, a plurality of vertical jacking rods 82 and a plurality of vertical connectors 83; the upper end of the vertical jacking rod 82 is a free end, and the lower end of the vertical jacking rod is fixedly connected with the top surface of the transverse push plate 81; the upper end of the vertical connector 83 is fixedly connected with the bottom surface of the transverse push plate 81, and the lower end of the vertical connector is used for being connected with the output end of the power mechanism. In this embodiment, the power mechanism is a cylinder or an oil cylinder.

In the die assembly process, the plurality of power mechanisms drive the plurality of vertical connectors 83 to ascend, the plurality of vertical connectors 83 drive the transverse push plate 81 and the vertical lifting rod 82 to ascend, and after the vertical lifting rod 82 abuts against the bottom surface of the third fixing plate 60, the convex bottom die 13 and the shaft sleeve 721 are driven to ascend until the convex bottom die 13 and the cavity are assembled; in the die assembly process, as the plurality of power mechanisms drive the vertical lifting rod 82 to ascend through the transverse push plate 81, when a certain power mechanism breaks down, the uniform stress of the vertical lifting rod 82 can be ensured.

In the demolding process, the plurality of vertical connectors 83 are driven by the plurality of power mechanisms to descend, the plurality of vertical connectors 83 drive the transverse push plate 81 and the vertical jacking rods 82 to descend, the third fixing plate 60, the convex bottom die 13 and the shaft sleeve 721 descend along with the gravity, when the shaft sleeve 721 slides along the guide shaft 722 and descends to be in contact with the top surface of the fixing seat 71, the fixing seat 71 supports the third fixing plate 60 to complete demolding, and the vertical jacking rods 82 can continuously descend to be separated from the bottom surface of the third fixing plate 60. After demolding, the vertical lifting rod 82 is separated from the bottom surface of the third fixing plate 60, so that the advantages of convenience in disassembly and assembly and long service life are achieved.

In a preferred embodiment of the present invention, the supporting mechanism 70 further includes a buffering structure 73, and the buffering structure 73 is connected between the third fixing plate 60 and the fixing base 71. Through setting up buffer structure 73, can play effectual cushioning effect, can absorb, cushion the impact that the gravity of third fixed plate 60, protruding die block 13 and axle sleeve 721 formed fixing base 71, take place very big striking sound when avoiding axle sleeve 721 to contact with fixing base 71 to can reduce the striking noise effectively.

In a preferred embodiment of the present invention, the buffer structure 73 includes a first connecting member 731, a second connecting member 732, a connecting shaft 733, and a spring 734; the first connecting piece 731 comprises two first vertical connecting plates 7311 and a first transverse connecting plate 7312 connected to the bottoms of the two first vertical connecting plates 7311, the upper ends of the two vertical connecting plates are respectively fixedly connected with the third fixing plate 60, and the first transverse connecting plate 7312 is provided with a through hole; the second connector 732 comprises a second vertical connecting plate 7321 and a second transverse connecting plate 7322 connected to the top of the second vertical connecting plate 7321, the bottom of the second vertical connecting plate 7321 is fixedly connected with the fixing base 71, and the free end of the second transverse connecting plate 7322 extends into between the two first vertical connecting plates 7311; one end of the connecting shaft 733 is fixedly mounted on the free end of the second transverse connecting plate 7322, and the other end thereof is inserted into the through hole; the spring 734 is sleeved on the connecting shaft 733, and has an upper end abutting against a free end of the second transverse connecting plate 7322 and a lower end abutting against the first transverse connecting plate 7312. Design like this, when third fixed plate 60, protruding die block 13 and axle sleeve 721 follow the decline in-process under the action of gravity, provide cushioning effect by spring 734, because the free end of second horizontal connecting plate 7322 stretches into between two first vertical connecting plates 7311, can play limiting displacement, in addition, the other end of connecting axle 733 is pegged graft in the perforating hole, can play the guide effect.

In the preferred embodiment of the present invention, the number of the buffer structures 73 is two, and they are symmetrically distributed at the left and right ends of the fixing base 71; the number of the guide structures 72 is two, and the guide structures are symmetrically distributed at the left end and the right end of the fixed seat 71 and are positioned at the inner side of the buffer structure 73. By the design, the stress is more balanced, and the stability is good.

In the preferred embodiment of the present invention, the bottom surface of the third fixing plate 60 is provided with a positioning hole 61, and the top of the guiding axle 722 can pass through the axle sleeve 721 to be inserted into the positioning hole 61. Design like this, can guarantee that drawing of patterns back guiding axle 722 closely cooperates with third fixed plate 60, and the location is more accurate, avoids third fixed plate 60 slow-moving, improves stability.

The utility model discloses in the implementation of preferred, be provided with on the fixing base 71 and supply the groove 711 of dodging that vertical jacking rod 82 passed, the quantity of vertical jacking rod 82 is three, and wherein two vertical jacking rod 82 symmetric distributions are in both ends about horizontal push pedal 81, and remaining vertical jacking rod 82 is located the middle part of horizontal push pedal 81, and its free end runs through and dodges the groove 711. By the design, the third fixing plate 60 is more balanced in stress, and the yield of products is improved.

The utility model discloses in the implementation of preferred, first fixed plate 20, first blowing half 11, two first bearing plates 40 are the integrated into one piece structure, and second fixed plate 30, second blowing half 12, two second bearing plates 50 are the integrated into one piece structure. By the design, the processing precision can be improved, and the material and processing cost can be reduced.

Example two:

referring to fig. 6, the present embodiment is characterized in that: the number of the blow mold assemblies is two, and the first fixing plates 20 of the two sets of blow mold assemblies are oppositely arranged.

The utility model discloses in the implementation of preferred, still including being used for fixing two fixed blocks 90 on the base of blow molding machine, two fixed blocks 90 are fixed respectively in one side of the both sides face of first blow molding half module 11, and each fixed block 90 respectively with lie in with two first bearing plate 40 fixed connection of one side.

The rest is the same as the first embodiment.

Other examples are as follows:

the utility model discloses a quantity of blow molding module subassembly is three or more groups, and the quantity of guide structure, vertical connector, vertical jacking rod can carry out corresponding adjustment according to actual conditions. While only certain features and embodiments of the application have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the scope and spirit of the invention in the claims.

Finally, it should be noted that: the above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention cannot be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are all within the protection scope of the present invention.

Claims

1. A blow mold structure comprising at least one set of blow mold assemblies; the blow mold assembly comprises:

a first holding plate for holding a first blow-molding half-mold;

a second holding plate for holding a second blow mold half;

characterized in that the blow mold assembly further comprises:

2. The blow mold structure of claim 1, wherein the support mechanism further comprises a cushion structure connected between the third fixing plate and the holder.

3. The blow mold structure of claim 2, wherein the cushion structure comprises a first connector, a second connector, a connecting shaft, a spring; the first connecting piece comprises two first vertical connecting plates and a first transverse connecting plate connected to the bottoms of the two first vertical connecting plates, the upper ends of the two vertical connecting plates are fixedly connected with the third fixing plate respectively, and the first transverse connecting plate is provided with a through hole; the second connecting piece comprises a second vertical connecting plate and a second transverse connecting plate connected to the top of the second vertical connecting plate, the bottom of the second vertical connecting plate is fixedly connected with the fixed seat, and the free end of the second transverse connecting plate extends into the space between the two first vertical connecting plates; one end of the connecting shaft is fixedly arranged on the free end of the second transverse connecting plate, and the other end of the connecting shaft is inserted into the through hole; the spring is sleeved on the connecting shaft, the upper end of the spring is abutted against the free end of the second transverse connecting plate, and the lower end of the spring is abutted against the first transverse connecting plate.

4. The blow mold structure according to claim 3, wherein the number of the buffer structures is two groups, and the two groups are symmetrically distributed at the left end and the right end of the fixed seat; the number of the guide structures is two, and the guide structures are symmetrically distributed at the left end and the right end of the fixed seat and are positioned at the inner side of the buffer structure.

5. The blow mold structure according to claim 3, wherein a positioning hole is provided on a bottom surface of the third fixing plate, and a top portion of the guide shaft can be inserted into the positioning hole through the shaft sleeve.

6. The blow mold structure of claim 1, wherein the number of vertical lift pins is two or more.

7. The blow mold structure according to claim 6, wherein the fixing base is provided with avoiding grooves for vertical lifting rods to pass through, the number of the vertical lifting rods is three, two of the vertical lifting rods are symmetrically distributed at the left end and the right end of the transverse pushing plate, the remaining vertical lifting rod is located in the middle of the transverse pushing plate, and the free end of the vertical lifting rod penetrates through the avoiding grooves.

8. The blow mold structure of claim 1, wherein the first stationary platen, the first blow mold half, and the two first bearing platens are integrally formed, and wherein the second stationary platen, the second blow mold half, and the two second bearing platens are integrally formed.

9. The blow mold structure according to any one of claims 1 to 8, wherein the number of the blow mold assemblies is two, and the first fixing plates of the two sets of blow mold assemblies are oppositely disposed.

10. A blow mold structure according to claim 9 further comprising two retaining blocks for securing to a base of the blow molding machine, the two retaining blocks being secured to one of the two sides of the first blow mold half, each retaining block being fixedly connected to a respective one of the two first bearing plates on the same side.