Abstract:
A plastic material injection molding machine comprises a mold having at least two mold portions and a handling system adapted to be inserted between the mold portions when the mold is in its open position, for transferring an article between the handling system and a predetermined mold portion. The handling system, moreover, comprises a transfer plate supported loosely therein. The handling system, further, is adapted to approach the predetermined mold portion such that prior to the transfer of the article a first reference means on the predetermined mold portion can be brought into a registering position with a second reference means on the transfer plate. A clutch is provided for bridging the loose support.

Description:
FIELD OF THE INVENTION 
     The invention is related to the field of injection molding plastic material articles. 
     More specifically, the invention is related to a plastic material injection molding machine comprising a mold having at least two mold portions and a handling system adapted to be inserted between the mold portions when the mold is in its open position, for transferring an article between the handling system and a predetermined mold portion, the handling system, moreover, comprising a transfer plate supported loosely therein, the handling system, further, being adapted to approach the predetermined mold portion such that prior to the transfer of the article a first reference means on the predetermined mold portion can be brought into a registering position with a second reference means on the transfer plate. 
     The invention is, further, related to a handling system having means for transferring an article between a handling system and a predetermined position, the handling system comprising a transfer plate supported loosely therein and being adapted to approach the predetermined position such that prior to the transfer of the article a first reference means on the predetermined position can be brought into a registering position with a second reference means on the transfer plate. 
     The invention, moreover, is related to a method for transferring an article between a handling system and a predetermined mold portion of a plastic material injection molding machine having a mold with at least two mold portions, the handling system being adapted to be inserted between the mold portions when the mold is in its open position, the handling system, moreover, comprising a transfer plate supported loosely therein, the handling system, further, being adapted to approach the predetermined mold portion such that prior to the transfer of the article a first reference means on the predetermined mold portion can be brought into a registering position with a second reference means on the transfer plate. 
     Finally, the invention is related to a method for transferring an article between a handling system and a predetermined position, the handling system comprising a transfer plate supported loosely therein, the handling system, further, being adapted to approach the predetermined position such that prior to the transfer of the article a first reference means on the predetermined position can be brought into a registering position with a second reference means on the transfer plate. 
     BACKGROUND OF THE INVENTION 
     A plastic material injection molding machine, a handling system as well as methods of the types specified before are known in the art. 
     In connection with the plastic material injection molding machines, so-called handling systems are used which, when the mold is open, are inserted between the mold portions which are then at a distance from each other, for executing various objectives. 
     The most important objective of a handling system is to pick up the finished injection-molded plastic material articles from the hollow cavities of the mold after the opening of the mold, when the plastic material articles are ejected from the hollow cavities by means of ejector pins. For that purpose the handling systems are provided with an arm adapted to be inserted between the mold portions, the arm being equipped with corresponding receiving means. The receiving means may be configured mechanically, pneumatically or otherwise. 
     These configurations are basically independent of how the mold of the injection molding machine is configured in detail, i.e. whether the mold consists only of two mold portions or whether the mold is configured as a so-called stack mold comprising a center platen and laterally adjoining mold portions. For these various applications the handling system needs only to be configured correspondingly by multiplication or otherwise. 
     A further objectives of handling systems consists to insert certain parts into the hollow cavities of the mold prior to the beginning of the injection cycle. These parts or devices are subsequently immersed in liquid plastic material when the mold is closed so that the finished plastic material articles are provided with inserts embedded therein. 
     Such inserts may be so-called “labels” as are utilized as cover surfaces for smart cards or the like. Inserts, however, may also be electrical connector elements, i.e. contact pins or the like, as an example being embedded into a socket of an electrical component during the injection process. Moreover, such inserts may be reinforcing devices, hinges, mechanical fasteners or the like. Insofar, the invention is in now way restricted. 
     With all these objectives of handling systems a basic problem exists in that during the insertion of the handling system or of the handling system arm, respectively, between the mold portions a coordination in position between the handling system or the arm, respectively, on the one hand and that predetermined mold portion on the other hand must be established that shall be approached by the handling system. Considering that handling systems, in particular as used in connection with highly complex injection molding machines with corresponding external dimensions have correspondingly long cantilevered arms, it is not always possible to achieve a precise coordination of the movements even if precise position drives are utilized. 
     The afore-mentioned problems also arise outside of the mold when the handling system with its arm is displaced into a position outside the plastic material injection molding machine. At this external position, for example, those finished injection-molded plastic material articles that had been unloaded from the mold before, are transferred to further stations or, in the case of inserting parts, these inserts are picked up at those external positions for being subsequently transferred into the hollow cavities of the mold. In any event, it is necessary to approach that position outside of the mold exactly when it is in a station outside of the machine. However, even there is no such station outside of the machine, a precise positioning is also mandatory because a precise initial position for the arm of the handling system must be established in order to enable a precise displacement towards its end position between the mold portions. 
     The afore-discussed problems are also of importance for handling systems as used in general applications, i.e. as are used outside the field of plastic material injection molding machines. The invention is, hence, not limited to this particular application but is related to all conceivable applications of handling systems irrespective of the particular technical field. 
     It is known in the art to provide the predetermined mold portion on the one hand and its opposed side of the handling system on the other hand with a reference means or mark which have to be brought into engagement with one another in order to ensure that during the transfer of the article an exact relative positioning between the handling system and the mold portion prevails. This, too, is independent of whether the term “transfer of the article” is to be understood to mean the un-loading of a finished injection-molded plastic material article or the deposition of an insert or the like. 
     In the simplest case the reference means on the mold portion on the one hand and on the handling system on the other hand are complementary mechanical elements, for example a bore and a pin. Preferably, the bore is provided with a canted or beveled insertion surface and the pin is pointed at its front tip. When the handling system is inserted between the mold portions in a radial direction (relative to the axis of the injection molding machine) and then approaches the predetermined mold portion in an axial direction and, further, when the reference means are not exactly flush with one another, the afore-mentioned canted or beveled insertion surface of the bore or the also above-mentioned pointing of the pin effects that the pin will be inserted into the bore even if there is a certain offset between the two. 
     However, one will easily appreciate that such a correction movement within a radial plane will effect a mechanical constraint within the handling system because the handling system is forced to move out of the nominal position that it had just attained. 
     It is, therefore, also known in the art to provide a separate transfer plate for the transfer of the article within the handling system or within the inserted arm of the handling system and to support the transfer plate loosely, for example elastically movable within that radial plane, in the handling system or its arm. 
     Accordingly, during a correction movement out of the attained nominal position in the meaning of what was discussed above, only the transfer plate is slightly shifted within the range of movement of its movable support whereas no mechanical constraint is exerted on the handling system. 
     However, this prior art handling system has the disadvantage that the movable support of the transfer plate within the handling system causes problems during a fast displacement of the handling system, in particular when the handling system is strongly accelerated or strongly decelerated. The movably supported transfer plate with its movable support will hit against its mechanical stop in these cases, wherein this will happen several times during a handling process, namely during each acceleration and each deceleration. One has to bear in mind insofar that in the interest of a minimum cycle time of the plastic material injection molding machine, it is desired to move the handling system as quickly as possible, i.e. with the highest possible accelerations and decelerations. 
     The uncontrolled oscillatory movement of the transfer plate within the handling system will not become apparent only acoustically but will result in a significant wear of the elastic support and, hence, in its breakdown within a very short period of time. This, again, results in downtimes of the plastic material injection molding machine so that the resulting productivity of the plastic material injection molding machine may get lost entirely or partially in spite of minimum cycle times. 
     It is, therefore, an object underlying the invention to provide a plastic material injection molding machine as well as a method of the kind specified at the outset such that the above-discussed disadvantages are avoided. 
     In particular, it shall become possible to make a correction in position also in a wrong positioning of the transfer plate when it has attained its nominal position without substantial mechanical reactions on the handling system. Moreover, this shall become possible without the need of limiting the velocity of displacement, in particular the accelerations and the decelerations of the handling system. 
     SUMMARY OF THE INVENTION 
     In a plastic material injection molding machine of the type specified at the outset, this object is achieved according to the invention in that a clutch is provided for bridging the loose support. 
     In a handling system specified at the outset, the object is achieved according to the invention in that a clutch is provided for bridging the loose support. 
     According to the first method mentioned at the outset, the object is achieved according to the invention in that the loose support is bridged by means of a clutch at least during the insertion of the handling system between the mold portions. 
     Finally, according to the second method specified at the out-set, the object is achieved according to the invention in that the loose support is bridged by means of a clutch at least before the approachment to the predetermined position. 
     The object underlying the invention is thus entirely solved. 
     If the movable support of the transfer plate is blocked at any time when it is not needed during the bringing into engagement of the reference means, one has no limiting side conditions with respect to the velocity, acceleration or deceleration of displacement. Instead, the handling system may be displaced with the maximum velocity, acceleration and deceleration as is possible for the particular design of the handling system with-out any influence on the mechanical stability of the transfer plate which is mechanically locked to the handling system during these movements because the clutch is closed. 
     The invention, therefore, has significant advantages in particular when large transfer plates are required as is the case for multiple tools having a very large number of hollow cavities for the simultaneous manufacture of a plurality of typically small plastic material articles. Such large transfer plates have correspondingly large masses. Also in such applications the invention allows to operate with very quick movements. 
     In a preferred embodiment of the invention, the movable support is configured by an elastic support. 
     This measure has the advantage that the movable transfer plate after having effected an elastic movement, will automatically return essentially into the same initial position so that no large corrections in movement are necessary, however, it is also possible to configure the support plastically or braked or otherwise. 
     In a preferred embodiment of the inventive injection molding machine, the transfer plate is supported in an arm of the handling system. 
     This measure, known per se, has the advantage that only a narrow arm has to be inserted between the mold portions so that the mold portions need only to be opened by a relatively small amount. However, according to the invention it is also possible to configure the transfer plate as the arm of the handling system as a whole, i.e. to support the entire arm movably within the handling system, for example elastically or otherwise. 
     In another preferred embodiment of the inventive machine, the predetermined mold portion has an open surface when the mold is in its open position, the transfer plate being supported to move elastically within the plane defined by the open surface. 
     This measure has the advantage that the transfer plate is not only supported elastically along an axis but along a plane instead defined by two axes, and may correspondingly be latched by means of the clutch so that also complex motional sequences may be effected while entering or leaving a particular position. 
     In another embodiment of the inventive machine and the inventive method the clutch is adapted to be opened overlapping in time with the bringing into a registering position of the reference means and to be closed overlapping in time with the bringing out of a registering position of the reference means. 
     This measure has the advantage that the mechanical latching or locking of the transfer plate may be transferred automatically from the handling system or its arm to the predetermined mold portion so that the transfer of the article between the mold portion and the transfer plate may be effected while these elements are precisely aligned relative to one another. This enhances, for example, the precision of embedded contact elements of electrical components being an essential quality feature of such components. 
     Moreover, these measures have the advantage that the elastic support of the transfer plate is set free effectively for the absolute minimum in time, i.e. the transfer step for the article between the predetermined mold portion and the transfer plate, while otherwise the transfer plate is mechanically latched on the handling system or its arm at any time. 
     Correspondingly, for another variation of the inventive machine and the inventive method, respectively, the clutch is adapted to be opened automatically when the handling system approaches the predetermined mold portion. 
     This measure has the further essential advantage that a separate control for the clutch is not necessary at all because the corresponding clutch elements are actuated by the approaching movement itself so that the opening process and the subsequent closing process of the clutch is effected in an optimum way without the necessity of a complicated control. 
     In a mechanical embodiment of this variation, the clutch is adapted to be actuated by means of a rod being axially dis-placeable relative to the transfer plate in the direction of approachment of the handling system towards the predetermined mold portion, the rod protruding from a surface of the transfer plate opposite the predetermined mold portion. 
     This measure has the advantage that the clutch is actuated in a very simple manner by actuating the corresponding elements during the approachment of the handling system by making mechanical contact. 
     According to an improvement of this embodiment, the rod has a front side being flush with the second reference means as viewed in the direction of approachment. 
     This measure has the advantage specified above that the bringing into engagement of the reference means on the one hand and the actuation of the clutch on the other hand are effected synchronously as is also the case for the corresponding opening process. 
     In this respect it is preferred when the rod is journalled within the arm to be displaced in a longitudinal direction, that the clutch is configured by a section of the rod and by a seat surface in the transfer plate associated to the rod section, the clutch immobilizing the rod section on the seat surface in a plane transversal to the direction of approachment when the rod is in a first operational axial position and letting the rod section move freely when the rod is in a second operational axial position. 
     This measure has the advantage that the clutch is configured mechanically in an extremely simple manner in that only a rod is shifted to and fro in an axial direction between two operational positions. 
     This holds true in particular if, according to another improvement of this variation, the rod section and the seat surface are configured as complementary cones. 
     This measure has the advantage that when the cones adjoin each other, a reliable mechanical lock is guaranteed within the plane whereas on the other hand when the cones are axially off-set from one another, a sufficient clearance is guaranteed along the two axes defining the plane. 
     In this regard it is further preferred when the rod is held in the first operational axial position under the action of a spring, the spring being compressed during the transition from the first to the second operational axial position. 
     This measure has the advantage that during the entire movement of the handling system into and out of the gap between the mold portions, the spring holds the clutch in its closed state so that the transfer plate is mechanically latched to the handling system or its arm, respectively. Only during the short period of time of transfer to the predetermined mold portion, the spring is compressed and the clutch is thereby opened, which, again, activates the elastic support of the transfer plate. 
     Moreover, the machine according to the invention is preferred when the transfer plate is fixed to the handling system in the direction of approachment of the handling system towards the predetermined mold portion. 
     This measure has the advantage that clutches of simple design may be operated by axially displacing the handling system, as well already explained in connection with the above-mentioned embodiments. A relative movement between the transfer plate and the handling system must be only be guaranteed within the plane. 
     In this connection, a design is preferred according to which the transfer plate is surrounded by a flange of the handling system in the direction of approachment. 
     This measure has the advantage that the afore-mentioned axial fixation may be achieved in a particular simple manner. 
     According to embodiments of the inventive machine, reference means are preferred which, when brought into the registering position, come to engage one another in a form-fitting relationship. This may be effected, as known per se, in that the reference means are configured as a bore, in particular a blind bore, and as a pin, respectively, as is known in the art and as has already been discussed above. 
     As already mentioned, the invention is not restricted to the application in plastic material injection molding machines. All of the afore-mentioned examples and advantages hold likewise true for general applications of handling systems as well as for the indicated methods for transferring an article. 
     Further advantages will become apparent from the description and the enclosed drawing. 
     It goes without saying that the afore-mentioned features and those that will be explained here and after may not only be used in the particularly given combination, but also in other combinations or alone without leaving the scope of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention are shown in the drawing and will be explained in the subsequent description. 
     FIG. 1 shows a schematic side elevational cross-sectional view of an embodiment of a plastic material injection molding machine according to the present invention, having its mold in the open position and a handling system inserted therein; and 
     FIGS. 2 and 3 show a detail of a portion of FIG. 1 for further embodiments of the invention, in two different operational positions. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1, reference numeral  10  as a whole indicates a plastic material injection molding machine of conventional design. 
     Plastic material injection molding machine  10  has a first mold portion  12  as well as a second mold portion  14 . Mold portions  12  and  14  are at a distance from each other in the depiction of FIG. 1 so that the mold is in its open position. 
     Second mold portion  14  in the embodiment shown is a stationary mold portion. In FIG. 1, a conventional extruder  16  is connected thereto from the right hand side. Liquid plastic material is fed to a hollow cavity  20  via a channel  18 . In the embodiment shown, hollow cavity  20  is only configured within second mold portion  14 . On first mold portion  12 , dashed lines and reference numeral  20 * indicated where hollow cavity  20  is located when the mold is closed. 
     In FIG. 1, a handling system indicated at  22  is inserted between mold portions  12  and  14 . Handling system  22  at its front end is configured as an arm  24 . By means of arm  24 , an insert  26  may be transferred from arm  24  to first mold portion  12 , by placing insert  26  on a surface  27  facing arm  24 . 
     In FIG. 1, the necessary axial movement of arm  24  is designated with a double arrow z symbolizing the direction of approachment and the direction of moving away arm  24  relative to first mold portion  12 . A radial plane extending under right angles thereto is indicated by a double arrow x. Radial plane x is the plane along which arm  24  is inserted between mold portions  12  and  14  or retracted therefrom, respectively. 
     It should again be mentioned at this instance that within the scope of the present description of embodiments, the application with plastic material injection molding machines is solely to be understood as an example. The invention may be utilized beyond that application also in other fields. Insofar, the handling system with its arm must not necessarily be approached to a mold portion but, speaking in more general terms, may also be approached to a predetermined position. 
     Moreover, it should also be emphasized that the movements of approachment also in the case of application with a plastic material injection molding machine are not limited to a movement of the arm of the handling system into the gap between the opened mold portions into the area of the hollow cavities. 
     The same problems namely arise also when the handling system is retracted from the mold and assumes a predetermined final position outside the injection molding machine. Further stations may be located there to which the finished plastic material articles shall be transferred or from which inserts for a subsequent injection molding process shall be picked up. In any event, a precise initial position outside the injection molding machine helps to make the entering movement reproducible. 
     In FIG. 1, dashed lines on surface  27  of first mold portion  12  likewise indicate where insert  26 * comes to lie within hollow cavity  20 * in the closed state of the mold. 
     It should be briefly mentioned at this instance that the case of application of inserting an insert  26  described here shall also be understood only as an example because the invention as a whole may be utilized advantageously when it is only intended to unload finished injection-molded plastic material articles from the hollow cavity. 
     Moreover, it should be mentioned that the term “insert” shall be understood to mean any part or device as already mentioned above. Insert  26  may, for example, be a set of contact elements for an electrical plug connector or something else. 
     As will be easily appreciated, it is essential for the quality of the plastic material article injection-molded within hollow cavity  20 * that insert  26 * is positioned at a predetermined location within the finished plastic material article. For that reason it is mandatory to make sure that insert  26  is placed onto surface  27  at a precisely determined nominal position. 
     For that purpose, a simple mechanical control is provided because for technical reasons and due to the fact that the design of the handling system may for practical reasons not be too complicated, it is hardly possible to make the trajectory control of arm  24  so precise that through an external control the required precision in position with respect to insert  26  may be guaranteed. 
     The simple mechanical control consists of an assembly comprising a first reference means within surface  27 , being, for example, configured as a blind bore  28 , the axis of which is designated at  29 . Arm  24  carries a pin  30  being designed complimentary to blind bore  28  and utilized as a second reference means. The axis of pin  30  is designated at  31 . 
     In order to simplify a positive engagement of blind bore  28  and pin  30  in a situation where axis  29  and  31  are not flush one with another, as indicated by Δx in FIG. 1, blind bore  28  is provided with a canted or beveled insertion surface  32  and pin  30  may likewise be pointed or beveled at its front end. 
     Arm  24  is now approached to first mold portion  12  in the z-direction. Simultaneously, pin  30  is inserted into blind bore  28 , wherein, however, arm  24  would have to be shifted by offset Δx in the x-direction which would impose a mechanical constraint on arm  24 . 
     For that reason, that area of a surface  33  of arm  24 , from which pin  30  protrudes with a front side  34 , is configured as a movably or loosely supported transfer plate  40 . This is symbolized in FIG. 1 by the fact that, for example, springs  42  as an elastic support or bearing are provided between transfer plate  40  and surrounding arm  24 . Springs  42  support transfer plate  40  movably or loosely within the entire radial plane x, i.e. also in a vertical direction relative to the plane of FIG.  1 . The term “elastic” shall be understood only as an example in this context. Also other types of support or bearing may be provided, for example a plastic support, a frictional or braked support or a support having no influence at all on the sequence of motions. 
     Further, it shall be stressed that movable transfer plate  40 , too, shall only be understood as an example. Instead of utilizing a relatively small transfer plate, it would be within the scope of the present invention to support the entire arm of the handling system in the afore-mentioned manner. The invention, insofar, is not restricted. 
     Due to its loose support, transfer plate  40  may be shifted by offset Δx within the x-plane without imposing a mechanical constraint or stress onto arm  24 . 
     On the other hand side, the loose support of the transfer plate  40  within arm  24  has the disadvantage that transfer plate  40  within certain limits is loose within arm  24  also in dynamic situations so that when dynamic loads are exerted on the system, transfer plate  40  may move within the limits of springs  42 . In practice, this means that transfer  40  will hit against surrounding arm  24  within its loose support during each acceleration or deceleration step, resulting in damages on the loose support over a longer period of time. Due to that, transfer plate  40  will rattle within arm  24  when the latter is repeatedly displaced within a corresponding acceleration or deceleration when entering into the mold or being retracted therefrom. Insofar, one has to bear in mind that the movements of handling system  22  shall be made as quick as possible in order to make the cycle time of the plastic material injection molding machine  10  as short as possible. 
     According to the invention, a switchable clutch  44  is, therefore, provided between transfer plate  40  and arm  24 . Clutch  44  is held closed except a short period of time so that springs  42  and likewise the loose support of transfer plate  40  are bridged. When clutch  44  is closed, transfer plate  40  is, hence, rigidly connected to arm  24  and may be displaced together with the latter without any limits. 
     Only when pin  30  approached blind bore  28  and a compensation shall be effected with respect to a potential position offset Δx, clutch  44  is briefly opened so that transfer plate  40  for being transferred is itself put into the state of loose support for a short period of time. However, as soon as the transfer process is terminated and arm  24  may again be retracted from first mold portion  12 , clutch  44  is again closed so that transfer plate  40  is again rigidly connected to arm  24 . 
     By doing so, it becomes possible that arm  24  or the entire handling system  22 , respectively, may be displaced with the maximum possible velocity, acceleration and deceleration, however, no mechanical constraints on arm  24  may occur due to position errors Δx. 
     It had already been mentioned that the problems of position errors may also occur outside the mold when the handling system with its arm approaches an external final position. 
     FIGS. 2 and 3 show further details of embodiments of clutch  44 . 
     FIG. 2 shows a state where arm  24  is still distant from first mold portion  12  and clutch  24 , therefore, is still closed. 
     As one may take from FIG. 2, clutch  44  essentially consists of an axially displaceable rod  50  having a longitudinal axis  51 . In FIG. 2, a head  52  of rod  50  extends to the left hand side and protrudes over surface  33  of transfer plate  40 . The front side of head  52  is designated at  53 . A dash-dot line  54  further indicates that front side  53  of head  52  in that operational position is essentially flush with front side  34  of pin  30 , when viewed in the x-plane. 
     In FIG. 2, there is a thinner cylindrical section  55  at the right hand side of head  52  which, in the area of head  52  is provided with a thread. By doing so, head  52  may be moved in an axial direction for adjustment purposes. A nut  58  is provided for a fixing of head  54  on rod  50  in its adjusted position. 
     In the area of head  52 , transfer plate  40  is provided with a receiving recess  59  into which head  52  may be pushed back as will be explained further below. 
     On the right hand side of thin cylindrical section  55  in FIG. 2, there is a conical section  60  tapering down towards head  52 . Conical section  60  in the operational position of FIG. 2 is seated against a complementary conical seat surface  62  of transfer plate  60 . 
     On the right hand side of conical section  60 , there is a cylindrical section  64  of rod  50  running in a cylindrical guide surface  66  of arm  24 . Seen as a whole, rod  50 , therefore, may be displaced along its axis  51  relative to transfer plate  40  and relative to arm  24 . 
     Arm  24  in the area of cylindrical guide surface  66  is configured as a sleeve-type extension  68  being open to the right hand side. A threaded cap  70  is screwed onto sleeve-type extension  68 . Threaded cap  70  may be rotated on extension  68  for adjustment purposes and is thereby displaced axially. A helical spring  72  is located between threaded cap  70  and cylindrical section  64  which, by appropriate rotation of threaded cap  70 , may be biased in different ways. 
     In FIG. 2, a flange  76  extending axially may be seen at the upper end of arm  24 . Flange  76  at its front end terminates in a protrusion  78 . Protrusion  78  surrounds transfer plate  40  so that a form-fitting receiving recess  80  for transfer plate  40  is configured in the terminal portion of arm  24 . An upper free end  82  of transfer plate is, hence, axially (z) fixed, however, may be displaced within the x-plane. 
     FIG. 2 clearly shows that transfer plate  40  in the position shown in FIG. 2 is also fixed within the x-plane. This is because conical section  60  is tightly seated against complementary conical section  62  and, hence, free end  82  of transfer plate  40  cannot move along a direction indicated with an arrow  84  because transfer plate  40 , as mentioned before, is coupled with rod  40  in the x-plane whereby transfer plate  40  is immobilized within the x-plane because rod  50  is seated within cylindrical guide surface  66  of arm  24 . In that position, clutch  44  is, therefore, closed and the radial distance of free end  82  from flange  76  is d 1 . 
     Whereas FIG. 2, as mentioned before, shows the open position already shown in FIG. 1 where arm  24  with transfer plate  24  is still at a distance from mold portion  12 , FIG. 3 shows the approached state. In FIG. 2, like elements are designated with like numerals. Elements that have been displaced are identified by an added apostrophe. 
     As one may easily appreciate by comparing FIGS. 2 and 3, due to the flush positioning  54 , head  52  of rod  50  comes to lie on surface  27  of first mold portion  12  when front side  34  of pin  30  enters into canted insertion surface  32  of blind bore  28 . 
     This means that clutch  44  is activated at the moment in time when the two reference means, i.e. blind bore  28  and pin  30  engage one another. It has already been mentioned that by turning head  52 , a certain axial adjustment my be provided insofar. 
     As soon as head  52  comes to lie on surface  27  and arm  24  continues its movement to the left hand side, rod  50  is shifted relative to transfer plate  40  and also relative to arm  24  to the right hand side against the action of spring  72 . As soon as that is the case, conical section  60  is lifted off complementary conical seat surface  62 . The fixation of transfer plate  40  to arm  24  in the x-plane is, thus, removed which had been active in the position of FIG.  2 . 
     In the position shown in FIG. 3, clutch  44  is, therefore, opened because the thinner cylindrical section  55 ′ may be displaced within certain limits in the x-plane, namely within an opening  86  of complementary conical seat surface  62  that is now lying free. For example, in the embodiment shown in FIG. 3, transfer plate  40 ′ was moved slightly downward relative to arm  24 ′ so that now the distance between free end  82 ′ from flange  76 ′ is d 2 , i.e. slightly larger as compared to distance d 1  in FIG.  2 . This has happened because pin  30 ′ had assumed an error position offset upwardly relative to blind bore  28  (cf. Δx in FIG. 1) with the consequence that transfer plate  40 ′ had to be slightly moved downwardly until pin  30 ′ could enter into blind bore  21 . 
     In that position, a transfer of insert  26 ′ onto surface  27  at a precise position is guaranteed. 
     If now arm  24 ′ is again moved to the right hand side from the position shown in FIG.  3  and pin  30 ′ slights out of blind bore  28 , conical surface  60 ′ will again be shifted onto complementary conical seat surface  62 ′ with the consequence that the initial position of FIG. 2 is again assumed and transfer plate  40  is again latched to arm  24  in the x-plane.