WO2001031990A1

WO2001031990A1 - Actuating rod for mould-carrying plate

Info

Publication number: WO2001031990A1
Application number: PCT/EP2000/002927
Authority: WO
Inventors: Jader Pavanetto; Massimo Rossi
Original assignee: SIPA Industrializzazione Progettazione e Automazione SpA
Current assignee: SIPA Industrializzazione Progettazione e Automazione SpA
Priority date: 1999-11-03
Filing date: 2000-05-02
Publication date: 2001-05-10
Anticipated expiration: 2002-05-03
Also published as: IT248150Y1; ITPN990044U1; ITPN990044V0

Abstract

Actuating rod (7) for a moving plate (3) supporting a half-mould assembly, comprising: a knockout table (1), a half-mould (2), a moving plate (3), a preform removing plate (4), a plurality of forming or moulding cores (5), a plurality of respective sliding cylinders (6), a respective plurality of actuating rods (7) which act on the sliding cylinders (6) and are provided in the form of two mutually, firmly and releasably joinable sections (10, 11). They are provided with respective extended members adapted to be coupled with each other (12) so as to enable them to be correctly reassembled between the respective sections of the respective actuating rod.

Description

ACTUATING ROD FOR MOULD-CARRYING PLATE

DESCRIPTION

The present invention refers to an improved bar for imparting and controlling the movement of appropriate devices, which will be referred to as sliding cylinders m the following description, and which are used in processes for moulding plastic articles

In particular the invention applies m a preferred manner to machines adapted to contemporaneously mould a plurality of plastic articles, the so-called preforms or parisons, whicn are intended to be then blow-moulded for transformation into appropnate fin a. containers, especially bottles, of plastic material

Although reference is made in the following description, owing also to reasons of greater descriptive simplicity and convenience, to a machine for moulding preforms of plastic materials, as used m combination with the preliminary melting and extrusion of said plastic material, it will be appreciated that the present invention equa_y applies to other kinds of uses, as long as these fall within the scope of the appended claims

As everyone m the art is well aware of, the process for moulding the preforms is generally carried out with the use of a moulding machine that is substantially formed by a fixed or stationary half- mould, which is integral or firmly joined with the structure of the same machine, and a moving half-mould adapted to move in a vertical direction and to be selectively closed into an appropnate position against said stationary half-mould

The moving haif-mould, the specific charactenstics of which are not descnbed here owing to their being well-known in the art, is associated externally to a moving mould-carrying or bolster plate and, internally, to a plate which is provided to remove the preforms from the mould as soon as the moulding operation is completed and to the outside of which there are applied a plurality of moulding or forming cores for said preforms

The motion of said plate away of the half-mould is ensured by a plurality of cylinders adapted to slide in respective cylindrical housings provided inside said half-mould, m wnich said cylinders are m turn dnven slidably by respective actuating rods that are partially contained in said moving plate and partially protruding on the opposite side with respect to said preform removal plate

Said actuating rods, in the external portion thereof, releasably engage a so- called knockout table which develops rectilmearly and the motion of which is transmitted by an appropnate actuating or dnvmg cylinder, usually of a hydraulic type

During operation after the moving half-mould has been moved away and before the preforms are knocked out, said actuating cylinder is appropriately operated and the thereby generated motion is transmitted m the given order, but at the same time, to said knockout table and, from this, to said actuating rods and, therefore, to said sjding cylinders and, from these, to said preform removal plate which owing to its being in this way displaced with respect to the moving half- mould, causes the preforms to be knocked out All this is anywav well-known to all those who are skilled in the art and has been reminded here to ^τhe sole purpose of more effectively introducing the technical context which the p: esent invention is actually referred to During the use of the moulding machine, operating conditions generally prevail or occur that make it necessary either for the mould to be changed or replaced or the operator to intervene on the forming cores in order to replace and/or repair them; m short, whenever the moving half-mould is disassembled, regardless of the reasons or circumstances, the same must obviously be then reassembled or a new one must be installed

Now, such an operation requires all of the above cited component pans to be duly realigned with respect to each other, in particular, disassembling of the moving half-mould calls for the sliding cylinders, which are contained m said half- mould, to be released and separated from the respective actuating rods Owing to the latter being usually screwed on to the respective sliding cylinders, it becomes necessary for these actuating rods to be acted upon in view of unscrewing said sliding cylinders therefrom

However, owing to these rods being coupled in an adjustable manner to the knockout table, the need necessarily anses for said knockout table to be duly released from said actuating rods

Such an operation can be carried out quite easily, considering that the coupling between the actuating rods and the knockout table is brought about by threading the actuating rods in the portion with which they engage said table, and by applying two appropriate bolts on each rod, on the opposite sides of the knockout table

It is further generally well known that the actuating rods must be accurately and exactly adjusted with respect to the knockout table so as to ensure, with the movement of said table, not only a perfect parallelism of the movement of the rods, but also the orthogonality thereof with respect to the contact surface of the preform removal plate

However, disassembling, le separating said rods from the knockout table causes the very accurate adjustment existing between said elements, and which has to be ensured and carefully maintained under any operating condition of the moulding machine, to be lost.

When the assembly has eventually to be reassembled, after the moving half- mould has been so removed, it therefore becomes absolutely necessary to each time go through a phase of very accurate adjustment of the actuating rods relative to the knockout table.

These operations of very accurate adjustment are inherently time-consuming and delicate to perform. Now, if the fact is considered here that such an adjustment must be carried out not just a smgle time, but as many times as the actuating rods actually are, so that they may sometimes amount to even some dozens of them, it can be easily inferred how disassembling the half-mould can actually turn out to be a quite expensive handling owing to both the amount of man-hours required and the long downtime imposed to the machine.

If the fact is finally considered that, owing to production-related or market- driven reasons, it may be necessary for moulds to be changed even once a day, the extreme overall burdensomeness of each mould changing operation, the duration of which may typically amount to as many as approx. two hours, can be readily and clearly inferred

Based on the above considerations, it is therefore a main purpose of the present invention to provide a a type of actuating rods whose disassembly and subsequent reassembly are such as to enable the time required for the adjustment thereof relative to the knockout table to be drastically reduced; furthermore, such actuating rods shall be easily implemented with the use of materials that are readily available in the art and, therefore, low-cost.

Such an aim of The present invention, along with further features thereof, is reached in an appai'atus that is made and operates as recited in the appended claims.

The present invention may take the form of a preferred, although not sole embodiment such as the one that is described m detail below by way of non- limiting example with reference to the accompanying drawings, m which

- Figure 1 is a vertical-section view of a portion of a moulding machine according to the present invention,

- Figure 2 is an exploded view of two sections of an actuating rod and the related joining and securing device according to the present invention,

- Figures 3, 4, 5 and 6 are as many perspective views of the actuating rod and the joining device shown m Figure 2, m which

- the two sections are separated from each other,

- the two sections are joined to each other, whereas the related securing device is still open and separated, - the two sections are jomed to each other and said securing device partially engages the two sections, but is still open, and

- the two sections are joined to each other and said securing device is closed and locked m its final working position, respectively

Reference will be made m the following description to a moulding machine which develops and moves vertically and in which the moving half-mould lies on the upper vertical of the respective stationary half-mould It wul however be appreciated that the invention is advantageous also in connection with and f oily apply also to any other type of moulding machine, m particular also the so-called horizontal-type moulding machines, in which the moving half-mould moves with a horizontal motion

With reference to the above Figures, a vertical-type moulding machine provided with an upper half-mould adapted to produce preforms of plastic material comprises

- a knockout table 1

- a half-mould 2, - a movmg plate 3 adapted to support said half-mould,

- a plate 4 for the removal of the preforms,

- a plurality of moulding or forming cores 5 for respective preforms,

- a plurality of respective sliding cylinders 6, - a respective plurality of actuating rods 7 adapted to act on respective ones of said sliding cylinders through a rectilinear translational motion,

and further comprises of course all those auxiliary components and equipment parts that are needed in view of enabling the moulding machine to operate correctly

Substantially, the present invention consists m providing the actuating rod 7 and more specifically, the portion thereof that engages the related sliding cylinder with both

a) the possibility for it to be both disconnectable from and re-connectable to the knockout table, and

b) the feature according to which a re-connection thereof does not require any further adjustment, since the first performed adjustment is actually maintained once for all

According to the present invention, these two requirements, although seemingly incompatible are met by means of

- a separ ation of the actuating rod into two selectively separable sections, one of which le, the upper section 10, is coupled to the knockout table, whereas the other one, le the .ower section 11 , fits into the movmg plate 1 and engages, at its lower extremity, the i elated sliding cylinder 6,

- a securing oi locking device 12 adapted to firmly secure said two sections to each other a__ter the joining thereof If said two sections are m fact capable of bemg quickly separated from and rejoined to each other without losmg the adjustment thereof relative to the knockout table, and therefore without any need for such an adjustment to be restored, the desired aim can be considered as bemg effectively reached

For effectively lockmg the actuating rod against the knockout table 1 there are furthermore provided a pair of bolts 8 and 9 through which it is possible for the required adjustment in the coupling of said two members 1 , 7 to each other to be earned out

According to the present invention, therefore, the two requirements defined under a) and b) above are capable of bemg simultaneously met by means of a smgle actuating rod adapted to be separated mto two distinct sections that must be capable of bemg re-joined to each other so as to exactly restore the initial geometry of the actuating rod that has been disassembled by the separation thereof

Such a perfect reassemblability of said two sections of a same actuating rod is therefore the absolutely necessary pre-condition for ensuring the capability of the moulding machine to be quickly restored m its ongmal working conditions and, therefore, the regular correct utilization thereof

This reassemblability of the two sections of a same actuatmg rod is ensured by some preferred embodiments of those portions of the two sections which must be jomed, m combmation with appropriate devices for lockmg said two sections when appropnately connected to each other

According to a preferred embodiment, said sections 10, 11 are provided, at the portions thereof mtended for mutual coupling, with respective outwardly extended, preferably flat members 1 , 13, m such a manner that

- said members 12, 13 are capable of bemg coupled with each other so as to ensure the possibility for the ongmal geometry of the actuatmg rod to be univocallv and unmistakably restored and - said lockmg or securing devices are adapted to keep said sections selectively locked together by actmg on said extended members 1 and 1

With particular reference to Figures 2 et seq., said extended members can be noticed to be substantially comprised of two flat rings connected to the coupling extremities of the respective sections, m such a manner that it will be sufficient for said rings 12 and 13 to be appropriately brought close to each other m order to ensure a correct reassembly of the respective actuating rod

Preferably, said locking devices comprise

- a first rigid flange 21 provided with a recess 22 adapted to accommodate a first portion of said two coupled flat rings,

- a second rigid flange 23 provided with a respective recess 24 adapted to accommodate a second portion of said rings when said flanges are coupled to each other, said first and said second portions bemg distinct from each other and sharing no portion or part with each other, said two ngid flanges are capable of bemg jomed to each other by means of appropriate joining means so as to firmly and securely accommodate said first and said second portion of said rings when they are so univocally coupled on to the respective coupling surfaces, m such a manner as to be able to lock said two sections m their jomed position

In order to ensure a firm lockmg of said two sections m their jomed condition, it is required that said two nngs be not only correctly coupled, but also kept firmly secured in such a position

In order to meet such a requirement in a simple and cost-effective manner, as well as to ensure that the simple assembly of said lockmg devices is effective m firmly securing said two sections to each other in the correct position automatically, it is advantageous if the surfaces 25, 26 of said nngs, opposed to the surfaces thereof winch are not mutually jomable, are m the shape of a frustum of a cone, and said recesses 22, 24 are also m the shape of corresponding frustums of a cone, so that said opposite surfaces 25, 26 and the internal surfaces of said recesses are provided with respective surface portions m mutual contact, which are capable of bemg compressed and locked-in by said flanges when the latter are clamped together

With reference to the Figures, said appropnate means for joining said flanges comprise suitable holes 30 provided m said flanges, as well as a pm 31 adapted to engage one of said holes, so as to enable said flanges to be fastened together by means of a mutually rotary motion thereof relative to said pm

With reference to Figures 3 through to 6, it can be noticed that, m practical operation, it will be sufficient for said lockmg device 12 to be disengaged, le released, in order to be able to act on the lower section 11 without involving or affecting the upper section 10 that keeps engagmg the knockout table and, therefore, maintains the desired adjustment

Furthermore, m order to ensure a correct restorability of the ongmal mutual orientation of said two sections relative to each other, le the possibility for them to be re-assembled m the same position and setup with respect to the direction of movement, a suitable cavity 33, havmg preferably a regular shape, eg a hexagonal shape (as shown m the Figure), is advantageously provided m the inner coupling surface 34 of the section 11 , as illustrated m Figure 3

On the corresponding coupling surface of the section 10 there is provided a protruding member (not shown), whose shape, arrangement and size are such as to make it adapted to exactly fit mto and engage said cavity 33, m such a manner as to as far as possible prevent said sections from bemg re-assembled m any other manner than the one that univocally and unmistakably ensures the correct ongmal assembly and adjustment of the actuating rod

In order to jom again the two sections with each other, it will therefore be sufficient for the two rmgs 12, 13 to be simply coupled again to each other, as this is practically allowed for by said cavity 33 and the correspondmg protrudmg member, and said lockmg device to be then clamped therearound , the frusto- conical shapes of both the surfaces 25 and 26 on the opposite side of the inner surfaces of said nngs, and the inner surface of the afore cited recesses, along with the appropnate selection of the dimensions of the various members mvolved, ensures that tightly clamping together said lockmg device 12, eg. by means of a threaded bolt 32 arranged as shown m the Figures, causes said nngs to get coupled m such a manner as to very accurately restore the ongmal setup, form and orientation of the related actuatmg rod

On the other hand, no remarkable force is required m this connection, smce said rod is only stressed axially, so that no risk actually exists for the two sections to loosen transversally owing to the work preformed by the respective actuatmg rod

When the actuating rod is re-assembled, the relative adjustment thereof is restored automatically, smce on the one side said adjustament of the upper section 10 relative to the knockout table 1 has actually never been altered and, on the other side, the position of the lower section 11 relative to the upper section 10 is restored exactly

Claims

1. Actuating rod for a moving plate for the support of a half-mould assembly, said assembly comprising:

- a knockout table ( 1 ) , - a half-mould (2),

- a moving plate (3) adapted to support said half-mould, - a plate (4) for the removal of the preforms,

- a plurality of moulding cores (5) for forming respective preforms,

- a plurality of respective sliding cylinders (6),

- a respective plurality of actuating rods (7) adapted to act on respective ones of said sliding cylinders through a rectilinear translational movement, characterized in that said actuating rods are provided in the form of two complementary sections (10, 11) adapted to be mutually, firmly and releasably joined with each other in the zone of mutual engagement thereof by means of appropriate locking devices (12).

2. Actuating rod according to claim 1, characterized in that said zone of mutual engagement of said two sections and said locking devices are arranged between said knockout table and said moving plate.

3. Actuating rod according to claim 2, characterized in that said two sections (10, 11) are provided with respective extended members adapted to be coupled with each other so as to enable the respective sections of a same actuating rod to be reassembled in their correct setup.

4. Actuating rod according to claim 3, characterized in that the coupling surfaces of said extended members are flat and preferably in an annular shape (12, 13), as well as orthogonal to the axis of the respective rod.

5. Actuating rod according to claim 3 or 4, characterized in that on the coupling surface of one of said sections there is provided an appropriate cavity (33) and on the coupling surface of the other section there is provided a protruding member adapted to engage said cavity (33) so as to ensure full restorability of the original mutual orientation of said sections forming the actuating rod.

6. Actuating rod according to any of the preceding claims 3 to 5, characterized in that said locking devices comprise;

- a first rigid flange (21) provided with a recess (22) adapted to accommodate a first portion of said two flat rings (12, 13) in their coupled condition,

- a second rigid flange (23) provided with a respective recess (24) adapted to accommodate a second portion of said rings when coupled to each other, said first and said second portion being distinct from each other and sharing no common parts; said two rigid flanges are joinable to each other by means of appropriate joining means so as to firmly accommodate said first and said second portion of said rings (12, 13) when univocally coupled on the respective coupling surfaces, so as to be able to firmly clamp said two sections in the joined position thereof.

7. Actuating rod according to claim 6, characterized in that

- the surfaces (25, 26) opposing the mutually joinable ones of said two rings are in the shape of a frustum of a cone, - said recesses (22, 24) are in the corresponding shape of a frustum of a cone, so that said opposite surfaces and the inner surfaces of said recesses have respective portions of surface in mutual contact.

8. Actuating rod according to claim 6 or 7, characterized in that said appropriate joining means of said first and said second flange (21 , 23) comprise a suitable hole

(30) provided in said flanges and a pin (31) adapted to engage said hole, so as to enable said two flanges to be clamped together by means of a mutually rotary motion thereof with respect to said pin (31).