EP1392486A1

EP1392486A1 - Method and device for inserting inserts while guiding and encapsulating the same by injection molding

Info

Publication number: EP1392486A1
Application number: EP02740588A
Authority: EP
Inventors: Richard Herbst; Jakob c/o Herkuma GmbH KAMMERLOHER; Kenneth Evan Johnson; Alexander Timothy Chenvainu; Thomas Aurele Christman
Original assignee: Hekuma GmbH
Current assignee: Hekuma GmbH
Priority date: 2001-05-14
Filing date: 2002-05-10
Publication date: 2004-03-03
Also published as: CA2447117A1; WO2002092315A1

Abstract

The invention relates to a method and device for injection molding plastic articles, particularly blade heads for wet shaving devices. Before the injection molding process, an insert, preferably a blade holder (50), is placed inside a cavity of a tool (12, 14) of a plastic injection molding machine. The insert is at least partially encapsulated by injection molding during the injection molding process. The insert is fed to the tool (12, 14) by first means (60) and is then placed inside the cavity by second means (22) while being guided (24) on the tool (12).

Description

METHOD AND DEVICE FOR INSERTING INSERTIONS UNDER GUIDE AND INJECTION

The invention relates to a method for injection molding plastic articles, in which an insert is inserted into a cavity of a tool of a plastic injection molding machine before the injection molding process and the insert is at least partially encapsulated during the injection molding process.

The invention further relates to a device for injection molding plastic articles, with a tool containing at least one cavity and with an arrangement for inserting an insert into the cavity prior to the injection molding process, which comprises first means for feeding the insert, the insert at least partially encapsulating during the injection molding process becomes.

A method and a device of the aforementioned type are known.

In plastic injection molding, it is known to insert so-called inserts into the cavity of the tool of the plastic injection molding machine or, in the case of a multiple tool, a corresponding number of inserts into the plurality of cavities of the tool before the injection molding process. The inserts can serve a wide variety of purposes. It is known to inject inserts for mechanical reinforcement of the plastic article. In the case of other plastic articles, electrical or electronic assemblies are injected into the plastic article. However, it is also known to only partially overmold insert parts so that portions of the insert part protruding from the finished plastic article can be used for mechanical or electrical purposes.

So-called blade heads are used in certain wet shavers. These blade heads are mounted on a holder of the wet shaver, usually movably, and can be exchanged for a new blade head after a certain number of shaves if the blades have become blunt. In these essentially flat, rectangular blade heads, a more or less solid plastic injection molded cheek is provided on the right and left side. Between these two cheeks extend a plurality of blades arranged one above the other and at a distance from one another, which are attached to the cheeks with their free ends. For reasons of stability, a plastic beam connecting the two cheeks is provided above and below the blades, which is referred to in technical terms as "soap strip" or "finguard".

In some conventional blade heads, the aforementioned plastic parts are manufactured by injection molding as a common, one-piece structure. The blades are then loosely inserted into this structure and then fixed with a metal clip. However, this process is complicated and takes a long time.

Now it would be conceivable to produce such blade heads similar to other known plastic parts, in which the insert parts are inserted into the cavity and then partially overmolded during the injection molding process. Then it is necessary during the injection molding process to keep the section of the insert not to be overmolded so tightly in the mold, ie to cover that this section does not come into contact with the injected liquid plastic. This is a very difficult matter because, as is known, the liquid plastic is injected into the cavity under very high pressure during injection molding, so that even with the smallest gaps between the section of the insert to be covered and the complementarily shaped wall of the cavity surrounding it. desired plastic can reach this section to be covered. This is particularly disadvantageous in the case of the use mentioned in the case of blade heads for wet shavers, because the plastic which has reached the blade area in an undesirable manner forms a type of film and thus the sharpness of the blade edge can be removed.

The invention is therefore based on the object of developing a method, a device, a blade head and a use of the type mentioned in such a way that the disadvantages mentioned above are avoided. In particular, the aim of the invention is to ensure that the sections of the insert which are not to be extrusion-coated are inserted precisely and thus with a high degree of tightness into the complementarily shaped section of the cavity, so that this section of the insert does not come into contact with the injected plastic with high certainty.

In a method of the type mentioned, this object is achieved according to the invention in that the insert is fed to the tool and then inserted into the cavity by means of a part of the tool under guidance on the tool.

In a device of the type mentioned in the introduction, the object is achieved in that second means, guided in the tool, are provided for taking over the insert part from the first means and for inserting it into the cavity.

Within the scope of the present invention, it was recognized for the first time that the problems described at the outset are due to the fact that the inserts are not inserted into the cavity with the necessary precision. Contrary to general expectations, the problem therefore does not lie in the fact that the complementarily designed section of the cavity is not sufficiently precisely complementary to the outer contour of the insert parts or that the insert parts are not sufficiently true to shape. Rather, the plastic injection molding process often does not succeed in conventional methods even if the insert and the complementary section of the cavity for the section of the insert not to be overmolded are precisely paired with one another.

The lack of precision when inserting the inserts, in turn, is essentially based on the knowledge gained in the context of the present invention that the insertion process is usually carried out by a handling system - and only by this handling system - which moves from the side between the halves of the tool that have moved apart and then the insert is moved first to the cavity, whereupon the insert is then transferred into the cavity by means of ejector pins or the like. This insertion or transfer process cannot be carried out with the required high precision because the handling system moves over relatively long distances and usually also along several axes relative to the tool halves, which are also movable. The result of this is that during the transfer process from the handling system into the cavity, it is not possible to ensure a sufficiently precise relative positioning of the cavity on the one hand and of the transfer point of the handling system on the other. These problems can be solved by centering the handling Systems on the tool, as is known per se from DE 199 49 851 AI, also not fundamentally solve.

In practice, this leads to the fact that the insert part is not inserted precisely at the location in the cavity at which the section of the insert part to be covered would lie flush against the complementary surface of the cavity. Rather, the insert is often inserted in one or both of the axes of travel offset by a minimal distance, so that gaps are created in this way, through which plastic undesirably reaches the area of the section of the insert to be covered.

In the context of the present invention, it has therefore been recognized that this problem can basically be solved by the fact that the last section of the insertion process is no longer carried out by the handling system, but rather by a separate arrangement, which in turn is mounted on the tool as a tool part. This arrangement, which can be designed as an insert block, receives the insert parts, for example via corresponding insertion bevels, centers them and then transfers them exactly in the centered state to the position in which the contours of the insert part and the cavity wall mentioned lie flush against one another.

In preferred developments of the invention, for only partially encapsulating the insert part, the cavity is provided with a first contour which is complementary to a second contour of the insert part at the portion thereof which is not to be extrusion-coated, the contours being placed flush against one another or abutting one another during the injection molding process. This measure has the advantage that the exact centering or alignment of the insert part in the tool in conjunction with the contours can be used to ensure that plastic cannot enter the covered area with certainty.

In a preferred development of this exemplary embodiment, the contours along a parting plane between halves of the tool are only partially provided in at least one sealing section.

This opens up the possibility, in a further development of the invention, of providing an insert section between two sealing sections in which the insert part is closed, in such a way that the insert section remains free of plastic during injection.

The aforementioned measures have the advantage that the seal with its exact requirements for the shape accuracy of the contours and for the positioning accuracy of the insert only has to be guaranteed in certain, for example, narrow zones, namely the sealing sections, while on the side facing away from the injected state of the Sealing section or between two such sealing sections, the insert can be more or less exposed and no further sealing functions are required there.

In this case, it is further preferred if a side section is provided on the side of the sealing sections facing away from the insert section, into which free ends of the insert protrude, the side section being injected with plastic during injection. This measure has the advantage that a reliable fixation of the insert parts is made possible because they are injected with their free ends in the region of the side section, for example into cheek-shaped sections of the plastic article.

In the aforementioned variant of the invention, it is also advantageously possible for a non-dimensionally stable plastic, for example an elastomer, to be injected at least into the side section.

As has already been explained above, it is known in the prior art to first insert loose parts loosely into the finished molded plastic article and then to fix them mechanically in a separate process. However, this procedure requires the use of a dimensionally stable plastic because the above-described joining process is only possible on a dimensionally stable plastic. But this means that the inserts are rigidly attached to the plastic article.

According to the last-mentioned procedure according to the present invention, however, a non-dimensionally stable plastic can also be used for the extrusion coating of the free ends of the insert part, because the insert parts are already fixed in the tool and therefore no joining forces are exerted on the section of the plastic article injected in the side areas ,

If the finished parts are then injected into a non-dimensionally stable plastic on the finished plastic article, they are resiliently supported, which is advantageous for many applications, in particular with wet shaving heads. In embodiments of the invention, it is particularly preferred if the insert is fed to the tool by means of a handling system or the first means are designed as a handling system.

These measures have the advantage that a quick and automated manufacturing process can be achieved.

It is particularly preferred in the context of the present invention if the insert is fed to an insert block that can be stored in the tool or the second means are designed as an insert block that can be stored in the tool.

These measures have the advantage that a relatively small element stored in the tool first transfers or takes over the insert part in an advanced position of the insert block and this is then moved back into the tool with the insert part being carried along in order to precisely insert the insert part there position.

In this respect, two variants are provided within the scope of the present invention:

In the first variant, the insert block is always in the tool and takes over the insert, for example from a handling system, while it is in the tool.

This procedure is advantageous when it comes to relatively manageable tools with only one or very few cavities and a total of only a few inserts to be inserted. In the case of complicated arrangements, so-called multiple tools, which may have dozens of cavities, into which several insert parts may have to be inserted, a second procedure is preferred.

In this second procedure, a plurality of insert blocks are used, these insert blocks being designed as interchangeable parts. These interchangeable blocks can then be equipped in an external circulation system. In the case of a multiple tool with 32 cavities and three inserts to be inserted, a total of 96 inserts have to be inserted. Since this insertion process takes some time, the external circulation system would also act as a buffer. The exchangeable blocks are then e.g. inserted into the tool by means of a handling system, namely in their guidance there on the tool.

Overall, this measure would have the advantage, given the complicated boundary conditions mentioned, that the time-consuming insertion process on the insert block takes place outside the injection molding machine and therefore the cycle time of the injection molding machine itself can be kept short.

In any case, it is preferred if the insert block is guided in the insert section of the tool.

It has already been mentioned that the inevitable inaccuracies in the positioning of the feed device, that is to say for example the handling system, are compensated for by the fact that the inserts during the transfer, for example from the Handling system in the insert block, centered or aligned, ie positioned exactly.

This centering preferably takes place only outside the sealing section, because conventional centering means, such as insertion bevels and the like, are undesirable in the region of the sealing section, since they would form an access for the plastic.

In a preferred embodiment of the device according to the invention, the tool has at least two tool halves which can be moved relative to one another along a common first axis, and the cavity is accessible when the tool halves are in the expanded state. It can thus be tools with two tool halves or so-called stack tools with three or more tool halves.

The first means, that is to say in particular a handling system, are more preferably movable between the tool halves when the tool halves are moved apart along a second axis which is essentially perpendicular to the first axis.

It is particularly preferred if the insert part can be transferred from the first means to the second means in the direction of the first axis.

A particularly good effect is achieved in this case if the second means can be moved along a guide in a tool half along the first axis. This measure has the advantage that the second means, for example the insert block, can “move” towards the retracted handling system, so to speak, and take over the insert part, in order to then return to the mold half. On this return path, the insert is then centered and brought precisely to the intended location in the cavity.

Further advantages result from the description and the attached drawing.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination indicated in each case, but also in other combinations or on their own without departing from the scope of the present invention.

An embodiment of the invention is shown in the drawing and is explained in more detail in the following description. Show it:

Figure 1 is a plan view of an embodiment of a tool of a plastic injection molding machine with two mold halves that can be used in the context of the present invention, shown in the expanded state;

Fig. 2 is a sectional view taken along the line II-II of Fig. 1; Fig. 3 is a sectional view taken along the line III-III of Fig. 1;

Fig. 4 is a sectional view taken along the line IV-IV of Fig. 1;

5 shows an illustration, similar to FIG. 1, but on a somewhat enlarged scale and only with one tool half, which is opposite a handling system in a starting position, in a first operating position;

Fig. 6 is a sectional view taken along the line VI-VI of Fig. 5;

FIG. 7 shows an illustration, similar to FIG. 5, but in a second operating position;

Fig. 8 is a sectional view taken along the line VIII-VIII of Fig. 7;

FIG. 9 shows a further illustration, similar to FIG. 5, but in a third operating position;

Fig. 10 is a sectional view taken along the line X-X of Fig. 9;

11 shows a further illustration, similar to FIG. 5, but in a fourth operating position; Fig. 12 is a sectional view taken along the line XII-Xii of Fig. 11;

13 shows a further illustration similar to FIG. 5, but in a fifth operating position;

Fig. 14 is a sectional view taken along the line XIV-XIV of Fig. 13;

15 shows a sectional illustration, similar to FIG. 14, but in a sixth operating position;

FIG. 16 shows a further sectional illustration, similar to FIG. 14, but in a seventh operating position;

FIG. 17 is a sectional view, in the plane II-II of FIG. 1, but with the tool closed;

Fig. 18 is a sectional view, similar to Fig. 17, but in the plane III-III of Fig. 1; and

19 shows a further illustration similar to FIG. 17, but in the plane IV-IV of FIG. 1.

In Fig. 1, 10 denotes a tool of a plastic injection molding machine. The tool 10 has a first tool half 12 and a second tool half 14, which lie against one another in the closed state along a common parting plane 15. The two tool halves 12 and 14 are relative to each other along a common axis 16, the so-called Z- Axis, movable. It goes without saying that this arrangement is only to be understood as an example and that other types of tools, in particular so-called stack tools, can also be used within the scope of the present invention.

1 to 4 show the tool 10 in the open state, in which the tool halves 12, 14 have moved apart. In a second axis 18, the so-called X-axis, which runs perpendicular to the first axis 16, a handling system can now move into the space between the two mold halves 12, 14 in order to remove finished plastic articles or insert inserts for a subsequent injection molding process. This will be explained in more detail below.

The first tool half 12 has side cheeks 20, between which an insert block 22 is located. The insert block 22 is mounted with a precision guide 24 in the first tool half 12, specifically in the direction of the first axis 16. The horizontal part of the precision guide 24 is indicated in FIG. 1 with 24a and the vertical part in FIG. 4 with 24b. This is to express that the insert block 22 is precisely supported and guided in the first tool half 12 both in the vertical and in the horizontal direction.

The tool halves 12, 14 are provided with a complex-shaped cavity, which is formed by numerous cavity sections and projections in order to produce a plastic article with a complex shape, into which an insert part is also to be injected, but only partially. A typical example of such a plastic article is a so-called blade head for wet shavers. With these blades heads are held one or more blades between two side cheeks made of plastic, the blades being exposed over the major part of their length so that shaving cream and cut off whiskers can get through between the blades. A bracket running parallel to the blades at a distance from them and connecting the two cheeks, which can also be arranged on both sides (so-called "soap strip" and "finguard"), gives the blade head the required stability. The blade head itself can in turn be articulated in a holder of the wet shaving apparatus which is to be guided by hand.

With these plastic articles, it is important that the sections of the inserts, i.e. in the example mentioned, the cutting edges of the razor blades, never come into contact with plastic during the injection molding process, because otherwise the sharpness of the cutting edges would be lost.

In the tool 10 shown in FIG. 1, both tool halves 12 and 14 are provided with a plurality of cavity sections 26 and 28 to 37, some of which have insertion bevels, as indicated at 27. In a corresponding manner, projections 38 to 42 are also provided, which are located in the cavity sections. The shape of this cavity or of the cavity sections and the associated projections depends on the shape of the plastic article to be produced, as can also be seen in FIGS. 2 to 4.

1 shows three sections on the first tool half 12 along the common parting plane 15. In the middle there is an insertion section Y symmetrical to the z-axis 16. These are bordered on both sides by narrower sealing sections X, which in turn are laterally delimited by side sections w. The meaning of these sections Y, X and W is as follows:

In the middle insertion section Y, the blades to be inserted should remain free of injected plastic, because this is the area of the blade head to be produced, which later forms the shaving area.

In order to prevent the injection of injected plastic into the insertion area Y, the sealing section X is provided on both sides, which must be made correspondingly tight. The inserted blades run through the sealing section X.

In the laterally delimiting side sections W, the lateral cheeks of the blade head are formed, into which the free ends of the blades are to be injected.

2, 3 and 4 are sectional views along the lines II-II, III-III and IV-IV of Fig. 1. They therefore represent the side portion W (Fig. 2), the sealing portion X (Fig. 3) or the insertion section Y (Fig. 4).

1 that the cheeks of the blade head are produced in the region of the side sections W by spraying out the cavities 26 and 33.

From Fig. 3 it can be seen that when the tool is closed, the protrusion 41 moves into the cavity 28, so that in the closed state, only the protrusion above the protrusion 41 then the partial cavity remaining in the cavity 28 remains together with the cavity 34. This total cavity forms the transition to the so-called "soap strip".

The same applies to the lower area, in which, when the tool is closed, the cavity 29 remains on the left side and the lower part of the cavity 35 on the right side, where it forms the transition to the "finguard".

Fig. 4 shows the insertion section Y. There, the "soap strip" is formed by the cavity 30 and the upper region of the cavity 36, and the "finguard" by the cavities 32 and 37. The region in between, in which the blades are located , is hermetically sealed, namely upwards by the projection 39, which engages in a recess 43 on the right in the cavity 36, and downwards by the projection 42, which enters the cavity 31 on the left. This means that the blades in this intermediate area are located within a cavity (see FIG. 17 below), but that this cavity is closed on all sides, so that access to liquid plastic is not possible.

With 44, 46 and 48 three so-called sealing contours are designated. This means the contours on cavity or protrusion sections of the tool halves 12, 14, which are complementarily adapted to surface sections of an insert part 50 that are not to be extrusion-coated. As will be shown (see FIG. 19), these sealing contours 44, 46, 48 are selected so that the sections of the inserts in question are completely sealed when the tool 10 is closed, that is, under none Circumstances can come into contact with the injected plastic.

It has already been said that the insert 50 in the illustrated embodiment is a blade holder for the blade head of a wet shaver mentioned above.

In the exemplary embodiment shown, two blade holders 50a, 50b are used for one blade head, that is to say they are inserted into the tool 10 in pairs.

Each blade holder 50 has a holding part 52 in which a blade 54 is located. The holding part 52 has a shoulder 56 on which a slider can engage in order to move the blade holder 50, as will be shown.

5 shows the first tool half 12 on the left-hand side and a handling system 60 on the right-hand side, which has been moved laterally into the position shown in the direction of the second axis 18.

The handling system 60 has a carrier 62 in which a slide 64 is mounted. In the illustration according to FIG. 5, the slide 64 has a pair of plungers 66a, 66b, 66c, 66d at the top and bottom, as can also be seen from the sectional illustration according to FIG. 6. The plungers 66a-66d run at their front free end in the region of clamping jaws 68a, 68b, 68c, 68d, between which the two lateral ends of the two blade holders 50a, 50b are held in a resilient manner. The carrier 62 is delimited on its left side in FIGS. 5 and 6 by a front edge 70. Two cheeks 72 protrude to the left over this front edge 70, in which the clamping jaws 68a-68d are located. There is therefore sufficient space between the cheeks 72 to hold the blade holders 50a, 50b there.

6 shows in the area of the right end of the insert block 22 two slots 74a and 74b with insertion bevels, which are aligned with the holding parts 52a, 52b of the blade holders 50a, 50b in the position of the handling system 60 shown, as indicated by 76.

5 and 6 characterize a first operating position, namely an initial position in which the handling system 60 has just been retracted laterally (second axis 18).

In a second operating position, the insert block 22 now moves to the right in its precision guide 24, as indicated by an arrow 78 in FIGS. 7 and 8. A front side 80 of the insert block 22 thus runs to the right.

It should be mentioned at this point that all of the movement processes described below do not necessarily have to take place sequentially, as is described below for the sake of clarity. Rather, some of the movement processes can also run in parallel or at least partially overlap in time, as the person skilled in the art will recognize from the description. A third operating position is now shown in FIGS. 9 and 10. In this operating position, the handling system 60 is moved to the left along the first axis 16, as indicated by an arrow 82. The travel path is dimensioned such that at the end of the travel path the front side 80 of the insert block 22 is just opposite an opposite front side 84 of the carrier 62 or the holding part 52.

11 and 12 now show the following fourth operating position, in which the slide 64 advances to the left, as indicated by an arrow 86. The plungers 66a-66d engage on the shoulders 56 of the holding parts 52 and push the holding parts 52 out of the clamping jaws 68 into the slots 74 of the insert block 22. This can already be done completely during this phase, i.e. until the stop at the bottom of the slots 74 or initially only partially. In any case, in this third operating position according to FIGS. 11 and 12, the front side 80 of the insert block 22 is still in the advanced position.

13 and 14 now show a fifth operating position, in which on the one hand the insert block 22 moves back to the left, as indicated by an arrow 88, but on the other hand the slide 64 "moves" as it were, as indicated by a further arrow 90. In this way, it is achieved that the blade holder 50 is held at both ends at the latest in this phase, that is to say in the X direction, and moved together with the insert block 22 to the left into the first tool half 12. At the end of this process, the blade holder 50 has reached its precise end position in the first tool half 12. Fig. 15 shows in a sixth operating position that the slide 64 returns to the right with the carrier 62 remaining stationary (arrow 91).

Fig. 16 shows in a seventh operating position that the slide 64 moves all the way back to the right and the handling system 60 also moves away from the first tool half 12 to the right, the starting position (first operating position) according to FIG. 6 having been reached again at the end of this process and the handling system 60 can be moved along the second axis 18 out of the space between the two tool halves 12 and 14.

The tool halves 12 and 14 are now moved towards each other, so that in the three cutting planes according to FIGS. 17, 18 and 19, which correspond to the axes II-II, III-III and IV-IV of Fig. 1, there shown relationships result.

It can be seen that the cavities already explained above are now formed, in which the plastic sections of the blade head are injection molded, which are required laterally to accommodate the blade holder 50 and over the length of the blade head to stabilize it.

What is important in the present context is the representation according to FIG. 18, which shows the sealing section X of the blade holder 50, in which the blades should be completely free of plastic. This works particularly well in the present case because the sealing contours 44, 46 and 48 fit together so closely as a result of the precise positioning of the blade holder 50 in the first tool half 12 that no gap remains, into which the liquid plastic could penetrate during injection.

It follows from the above description of the exemplary embodiment that the positional inaccuracy when feeding the blade holders 50 is compensated for only by the fact that the blade holders 50 are inserted exclusively within the insertion section Y and exclusively on the insertion block 22 and are thus centered and aligned. This takes place at the slots 74 with a corresponding insertion bevel, as can be seen in particular from FIGS. 10 and 12.

The blade holders 50 then have a precise position relative to the insert block 22. When the insert block 22 then transfers the blade holders 50 into the cavity, the blade holders lie exactly in such a way that the sealing section X is realized in the region of the sealing contours 44, 46 and 48 when the tool is closed becomes. No centering takes place in the sealing section X itself.

In a variant of the exemplary embodiment described above, which is particularly suitable for multiple tools with a large number of cavities in the same tool, the corresponding multiple insert blocks are formed. These exchangeable blocks are fed to an external circulation system and fitted outside of the injection molding machine. For example, with 32 cavities, each with three blades to be inserted, are for insert a total of 96 blades per injection molding process, which takes some time.

This loading time can be compensated for in the external circulation system, which serves as a buffer.

In this case, the interchangeable blocks are inserted into the cavities of the tool by means of a corresponding handling system, as has already been described in principle above for the insertion process of the blades.

In some applications it is preferred if a plastic is injected which has special properties with regard to the objects to be inserted.

In the application of blade heads for wet shavers, according to the invention e.g. provided to form at least the lateral cheeks of the blade head, into which the free ends of the blades are injected, from a non-dimensionally stable plastic, preferably an elastomer.

Either the entire blade head can consist of such an elastomer or only the area of the side cheeks.

This would have the consequence that the blades are elastically supported at both ends, which would improve the shaving comfort when using the blade head.

Claims

claims

1. A method for injection molding plastic articles, in which an insert is inserted into a cavity (26, 28-36) of a tool (12, 14) of a plastic injection molding machine before the injection molding process, and the insert is at least partially overmolded during the injection molding process, characterized in that that the insert is fed to the tool (12, 14) and then inserted into the cavity (26, 28-36) by means of a part of the tool (12, 14) under guidance (24) on the tool (12).

2. The method according to claim 1, characterized in that for only partially encapsulating the insert part of the cavity (28 - 36) is provided with a first contour (44, 48) which is complementary to a second contour (46) of the insert part thereof is to be molded section, the contours (44 - 48) being placed flush against one another during the injection molding process.

3. The method according to claim 1 or 2, characterized in that the contours (44, 46, 48) along a parting plane (15) between halves of the tool (12, 14) are only partially provided in at least one sealing section (X).

4. The method according to claim 3, characterized in that two sealing sections (X) include an insert section (Y) between them, in which the insert part is removed. locks is such that when inserting the insert section remains free of plastic.

5. The method according to claim 4, characterized in that on the side facing away from the insert portion (Y) of the sealing portions (X) a side portion (W) is provided, protrude into the free ends of the insert part, and that the side portion (W) during injection is sprayed out with plastic.

6. The method according to claim 5, characterized in that a non-dimensionally stable plastic is injected at least into the side section (W).

7. The method according to claim 6, characterized in that the plastic is an elastomer.

8. The method according to one or more of claims 1 to 7, characterized in that the insert part of the tool (12, 14) is fed by means of a handling system (60).

9. The method according to one or more of claims 1 to 8, characterized in that the insert is supplied to an insert block (22) which can be stored in the tool (12).

10. The method according to claim 9, characterized in that the insert is fed to the insert block (22) when the insert block (22) is in the tool (12).

11. The method according to claim 8 and 10, characterized in that the insert is fed to the insert block (22) by means of the handling system (60).

12. The method according to claim 9, characterized in that the insert is fed to the insert block (22) when the insert block (22) is outside the tool (12, 14).

13. The method according to claim 12, characterized in that a plurality of insert blocks are fitted outside the tool and the fitted insert blocks are supplied in succession individually or in groups to the tool in groups with several cavities in the tool.

14. The method according to claim 4 and one or more of claims 9 to 13, characterized in that the insert block (22) is guided in the insert section (Y) on the tool (12).

15. The method according to one or more of claims 1 to 14, characterized in that the insert is centered when feeding on the tool (12).

16. The method according to claim 3 and 15, characterized in that the insert is centered only outside the sealing section (X).

17. The method according to claim 9 and 16, characterized in that the insert is centered on the insert block (22).

18. Device for injection molding plastic articles, with a tool (12) containing at least one cavity (26, 28 - 36) and with an arrangement for inserting an insert into the cavity (26, 28 - 36) before the injection molding process (12, 14), which comprises first means for feeding the insert, the insert being at least partially encapsulated during the injection molding process, characterized in that second means (24) guided in the tool (12) for receiving the insert from the first means and for inserting it are provided in the cavity (28-36).

19. The apparatus according to claim 18, characterized in that for only partially overmolding the insert, the cavity (26, 28 - 36) is provided with a first contour (44, 48) which is complementary to a second contour (46) of the insert which is not formed to the overmolded section, and that the contours (44 - 48) lie flush against one another during the injection molding process.

20. The apparatus according to claim 19, characterized in that the contours (44, 46, 48) along a parting plane (15) between halves of the tool (12, 14) are only partially provided in at least one sealing section (X).

21. The apparatus according to claim 20, characterized in that two sealing sections (X) include an insert section (Y) between them, in which the insert part is closed, such that the insert section remains free of plastic when injected.

22. The apparatus according to claim 21, characterized in that on the side of the sealing portions (X) facing away from the insertion portion (Y) a side portion (W) is provided, protrude into the free ends of the insert, and that the side portion (W) during injection can be sprayed out with plastic.

23. The device according to claim 22, characterized in that a non-dimensionally stable plastic can be injected at least in the side portion (W).

24. The device according to claim 23, characterized in that the plastic is an elastomer.

25. The apparatus of claim 23 or 24, characterized in that the first means are designed as a handling system (60).

26. The device according to one or more of claims 18 to 25, characterized in that the second means are designed as an insert block (22) which can be stored in the tool (12).

27. The apparatus according to claim 26, characterized in that the insert part of the insert block (22) can be fed when the insert block (22) is in the tool (12).

28. The apparatus of claim 25 and 27, characterized in that the insert part of the insert block (22) by means of the handling system (60) can be fed.

29. The device according to claim 26, characterized in that the insert part of the insert block (22) can be fed when the insert block (22) is outside the tool (12, 14).

30. The apparatus according to claim 29, characterized in that a plurality of insert blocks is designed as interchangeable parts, that means for populating the insert blocks outside the tool and means for feeding the fitted insert blocks to the tool alternately one after the other or in groups with several cavities in the tool are.

31. The device according to claim 21 and one or more of claims 26 to 30, characterized in that the insert block (22) is guided in the insert section (Y) on the tool (12).

32. Device according to one or more of claims 18 to 26, characterized in that the tool (12, 14) is provided with centering means.

33. Apparatus according to claim 20 and 32, characterized in that the centering means are provided only outside the sealing section (X).

34. Apparatus according to claim 26 and 33, characterized in that the centering means are provided on the insert block (22).

35. Device according to one or more of claims 18 to 34, characterized in that the tool has at least two tool halves (12, 14) which can be moved relative to one another along a common first axis (16), and in that the cavity (26, 28-36 ) is accessible when the tool halves (12, 14) are in the extended state.

36. Apparatus according to claim 35, characterized in that when the tool halves (12, 14) have moved apart, the first means can be moved between the tool halves (12, 14) along a second axis (18) which runs essentially perpendicular to the first axis (16).

37. Apparatus according to claim 36, characterized in that the insert part can be transferred from the first means to the second means in the direction of the first axis (16).

38. Apparatus according to claim 37, characterized in that the second means along a guide (24) in a tool half (12) can be moved along the first axis.

39. Apparatus according to claim 37 or 38, characterized in that the first means have a slide (65) acting in the direction of the first axis (16).