Method for handling individual parts, handling systems, and grouping unit

Abstract

A handling system and/or a grouping unit of a handling system and a method for handling individual parts that have to be removed from a preceding production process, in particular injection-molded parts in the form of pipette tips that are produced in groups in an injection molding machine with a multiple tool and must be removed from the multiple tool for the further handling, the multiple tool including at least one distributing star having a plurality of mold cavities, whereby a removal arrangement is defined by the multiple tool for the further handling of the injection-molded parts. The method includes removing the finished injection molded parts, loading the parts into a grouping unit to produce a grid arrangement, and removing the parts from one grouping unit with a second grouping unit.

Claims

1. A method for handling individual parts which have to be removed from a preceding production process, in particular injection molded parts in the form of pipette tips (2), which are produced in large numbers in an injection molding machine (3) using a multi-cavity mold (4) and have to be removed from the multi-cavity mold (4) for further handling, wherein the multi-cavity mold (4) has at least one radial runner system with a plurality of mold cavities, whereby a removal assembly is provided by the multi-cavity mold (4) for further handling of injection molded parts, the method comprising: a) removing the finished injection molded parts from all existing mold cavities of the multi-cavity mold (4) at once in a single method step and delivered to a transfer unit (13), which, in the subsequent course of the method, transfers the injection molded parts into a first grouping unit (14), b) loading the injection molded parts into the first grouping unit (14) in the form of a two-dimensional grid, wherein the grid has at least two rows each with two injection molded parts, c) when loaded, moving with the first grouping unit (14) the injection molded parts of parallel mutually adjacent rows (R1, R2) toward one another, so as to produce a more compact grid arrangement of the injection molded parts in a first coordinate direction, d) then removing the injection molded parts from the first grouping unit (14) with a second grouping unit (24), wherein the distance between the rows in the second coordinate direction is likewise reduced using the second grouping unit (24), so as to produce a more compact, tighter grid in both coordinate directions.

2. The method according to claim 1, wherein the removal assembly specified by the multi-cavity mold (4) for the injection molded parts has a regular convex polygon with an even number (n) of vertices on a circumcircle (7, 8, 42, 44, 46, 48, 50, 52), wherein the injection molded parts lie at the vertices of the polygon with a midline C that divides the number of injection molded parts symmetrically and in the case of a number greater than four vertices/injection molded parts the following intermediate step is performed between method steps a) and b): a.sub.1) moving innermost injection molded parts relative to the midline (C) are moved outward until they are aligned in the same line with the outlying injection molded parts, such that two parallel rows (R1, R2) are formed from all (n) injection molded parts.

3. The method according to claim 2, wherein the midline (C) is defined in the first grouping unit (14) and/or in the second grouping unit (24), which midline lies symmetrically between the parallel adjacent rows of injection molded parts, and in that the adjacent rows of injection molded parts are moved symmetrically toward the midline (C).

Description

(1) The invention is illustrated below by way of example in drawings and described in detail with reference to several figures, in which:

(2) FIG. 1 is a schematic representation a handling system according to the invention for injection molded parts,

(3) FIG. 2 shows a portion of the handling system according to FIG. 1 with depicted removal unit and transfer unit,

(4) FIG. 3 shows a portion of the handling system according to FIG. 1, with the transfer unit and a first grouping unit,

(5) FIG. 4 shows the first grouping unit according to FIG. 3, comprising support strips, depicted in the spread-out state thereof,

(6) FIG. 5 shows the first grouping unit according to FIG. 3 with its support strips in the closed state,

(7) FIG. 6 shows the first grouping unit according to FIG. 5 and a second grouping unit for receiving suspended injection molded parts,

(8) FIG. 7 is a view from below onto the second grouping unit with the support strips thereof in the spread-out state,

(9) FIG. 8 shows the second grouping unit according to FIG. 7 with its support strips in the closed state,

(10) FIG. 9 shows a finished part holder loaded with injection molded parts in a grid arrangement,

(11) FIG. 10 shows a portion of the first grouping unit according to FIG. 4 with support strips in the spread-out state,

(12) FIG. 11 shows a pusher element of the grouping unit according to FIGS. 4, 5 and 10,

(13) FIG. 12 shows a portion of the first grouping unit according to FIG. 5 with support strips in the spread-out state,

(14) FIG. 13 shows a portion of the first grouping unit according to FIG. 5 with driver elements provided on the support strips,

(15) FIG. 14a shows a 4-sided removal assembly based on a multi-cavity mold for injection molding with two radial runner systems,

(16) FIG. 14b shows a 6-sided removal assembly based on a multi-cavity mold for injection molding with two radial runner systems,

(17) FIG. 14c shows an 8-sided removal assembly based on a multi-cavity mold for injection molding with two radial runner systems,

(18) FIG. 14d shows a 10-sided removal assembly based on a multi-cavity mold for injection molding with two radial runner systems,

(19) FIG. 14e shows a 12-sided removal assembly based on a multi-cavity mold for injection molding with two radial runner systems,

(20) FIG. 15 shows a repositioning device for an 8-sided removal assembly of injection molded parts, for which a polygonal starting position on a circumcircle is provided,

(21) FIG. 16 shows the repositioning device according to FIG. 15 in a repositioned position for a two-row arrangement of in each case four injection molded parts.

(22) FIG. 1 is a schematic diagram of a handling system 1 for individual parts, which have to be removed from a preceding production process, the individual parts here being pipette tips 2 which are produced in large numbers in an injection molding machine 3 using a multi-cavity mold 4.

(23) For further handling, these injection molded parts (pipette tips) must be removed from the multi-cavity mold 4, wherein the multi-cavity mold has at least one radial runner system with a plurality of mold cavities, whereby a removal assembly is fixedly specified by the multi-cavity mold 4 for further handling of these injection molded parts.

(24) Right at the end of the handling steps, the pipette tips should be arranged compactly and be capable of being delivered to a finished part holder 5. The injection molding machine 3 and the finished part holder 5 are depicted in FIG. 1 for the sake of completeness. However, they are not part of the handling system.

(25) The multi-cavity mold contains a systematic arrangement of the mold cavities. According to FIG. 1, the pipette tips come from such a multi-cavity mold 4, which has eight radial runner systems, wherein each radial runner system comprises four mold cavities. In the present example, the eight radial runner systems are arranged in two rows one above the other. The top row comprises four radial runner systems, each of which forms a group of 4 pipette tips arranged on a circumcircle 7. A bottom row comprises a further four radial runner systems with groups of 4 pipette tips, which are arranged on a circumcircle 8. In this way, the removal assembly according to FIG. 1 forms an array of 64 pipette tips, which lie in a vertical plane.

(26) The removal unit 6 serves to transfer all 64 pipette tips in the stated vertical array out of the multi-cavity mold 4. In the present example, the multi-cavity mold is formed of two mold parts 4a and 4b. The two mold parts may open and close at a vertical parting plane. To this end, one mold part 4a is arranged stationarily and the other mold part 4b movably, so as by this movement to bring about opening and closing of the multi-cavity mold 4.

(27) The removal unit 6 is moved toward the multi-cavity mold 4 when the latter is opened, in order then to accept finished produced pipette tips 2.

(28) On its stationary mold part 4a, the multi-cavity mold comprises a mandrel 9 for each pipette tip, which mandrel is part of the mold cavity and serves to shape the inner contour of the pipette tip 2. When the multi-cavity mold 4 is in the open state, finished injection molded pipette tips may initially remain on the projecting mandrel 9 and are then pushed down from the mandrel using an ejector (not shown) and into receiving openings 10, which are provided in the removal unit 6. The removal unit is moved for this purpose between the open mold parts into an exact position in which their receiving openings and the mandrels of the multi-cavity mold are brought exactly into congruence. Then the ejector is actuated to push the pipette tips 2 off the mandrels 9 in the direction of the receiving openings 10 of the removal unit 6. The ejector stroke is of such magnitude that in each case the free end of the pipette tip can be moved somewhat into the receiving opening with one ejection stroke. Acceptance of the pipette tips is assisted by providing the removal unit 6 with a suction air device (not shown). The suction air device is connected with the receiving openings 10 and may, if need be, generate in the receiving openings 10 a negative pressure relative to the ambient pressure, to attach the pipette tips 2 by suction and hold them firm.

(29) When the removal unit 6 is loaded with the pipette tips 2, it retains its vertical orientation and is moved out of the region of the injection molding machine 3. In the present exemplary embodiment, a linear guide 11 and a linear motor 12 are provided for moving out the removal unit. The removal unit 6 can thus not only be moved in a precisely positioned manner into the multi-cavity mold 4, but also moved out when loaded and conveyed to a transfer unit. At the same time, the removal unit 6 continues to retain its vertical orientation.

(30) The object of the transfer unit 13 illustrated in FIGS. 2 and 3 is to accept the array of pipette tips 2 in vertical orientation from the removal unit 6 and then transfer it into a first grouping unit 14.

(31) To this end, the transfer unit 13 is provided with transfer mandrels 15 for each pipette tip 2. The transfer mandrel fits in each case into the opening in the pipette tip. Furthermore, a movement device is assigned to move the transfer mandrels 15 into the openings in the pipette tips 2. With the pipette tips situated thereon, the transfer mandrels 15 are moved in the opposite direction fully out of the receiving openings 10 of the removal unit. So that the pipette tips 2 are firmly held on the transfer mandrels, the latter are connected to a suction air device (not shown). If need be, the suction air device generates a negative pressure relative to ambient pressure. The negative pressure sucks the pipette tip onto the transfer mandrel 15 and holds it firmly thereon.

(32) The array of pipette tips 2 is then rotated out of their vertical orientation into a horizontal orientation. Each transfer mandrel 15 is then oriented suspended vertically downward and the pipette tips 2 are firmly held suspended on the transfer mandrels 15 using the connected suction air device, which generates an appropriate negative pressure.

(33) Below the horizontally oriented array of pipette tips is located the stated first grouping unit 14, which has eight support strips 16 next to one another, wherein in each support strip a row of eight receiving openings 17 is provided for pipette tips 2. In this case, the receiving openings 17 of all the support strips are arranged congruently with the horizontally oriented array of pipette tips 2 still located in the transfer unit. In order to transfer the pipette tips into the receiving openings 17 of the support strips 16 of the first grouping unit 14, the suction air device is switched off. Either the pipette tips fall down and into the receiving openings 17 or the transfer unit 13 is lowered until the pipette tips project somewhat into the receiving openings 17, the suction air device then being switched off and the pipette tips being received securely in the receiving openings 17.

(34) The first grouping unit 14 receives pipette tips only when they are already present in a row arrangement with an identical number of pipette tips per row, as in the exemplary embodiment in FIGS. 1-3, which all provide a grid arrangement or array with 8 rows with 8 pipette tips per row.

(35) If, on the other hand, the multi-cavity mold has radial runner systems with mold cavities in a 6-sided, 8-sided, 10-sided or 12-sided polygonal arrangement, then this arrangement must firstly be changed into a two-row arrangement with 2 rows each with 3 pipette tips (23) or 24, 25 or 26 pipette tips. To this end, a further developed transfer unit is proposed further below with reference to FIGS. 15 and 16.

(36) The first grouping unit 14 is shown separately in FIG. 4. Here, the eight support strips 16 are again visible, arranged parallel to one another. Each support strip 16 contains one row with eight receiving openings 17, which are in each case arranged at identical positions in the support strip 16 and with identical spacings within the row. In FIG. 4, the receiving openings 17 are each loaded with a pipette tip 2. Each pipette tip 2 rests in the receiving opening. It may be held upright in the receiving opening 17 or a circumferential shoulder or a conical circumferential region of the pipette tip 2 is held at the edge of the receiving opening 17.

(37) Each support strip 16 of the first grouping unit 14 is mounted in each case by way of a pair of guide rails 18 and on the guide rails a pair of guide carriages 19 is arranged. The ends of the support strip are connected with the respective guide carriage 19. In the present exemplary embodiment, overall three pairs of guide rails 18, 20 and 21 are provided, although in principle one pair could suffice for all the support strips. In the present case, however, this would disadvantageously lead to the support strips 16 not being able to be moved as close together as desired. The reason for this lies in the size of the available guide carriages 19. If the guide carriages of all the support strips were to run on just one guide rail, then the size of the guide carriages 19 would specify how close the support strips 16 could be pushed together. Since the support strips are narrow, excessively large gaps would arise between the individual support strips. This is remedied by providing the stated three pairs of guide rails 18, 20 and 21, which allows the outer, longer support strips to be provided with cutouts for the guide carriages 19 of the adjacent inner support strips. In this way, it is ensured that the guide carriages of the inner support strips have space and can pass through the cutout in the longer support strips. In this manner, all the support strips 16 can be moved really close together.

(38) As is clear from looking at FIGS. 4 and 5 together, the support strips 16 are movable transversely of their longitudinal extent and provision is made to move the eight support strips symmetrically relative to a midline C. In each case, four support strips are moved on the one symmetrical side and the other four support strips are moved on the opposing symmetrical side. The support strips may be moved apart from one another, as is shown in FIG. 4 and denoted spread-out state. To adjust the exact end position for each support strip 16 in the spread-out state, in each case one outer limit stop 22 is provided, which limits the movement.

(39) In FIG. 5, the grouping unit 14 is shown with its support strips 16 in the closed state. All the support strips have been moved close together. This brings about a compact arrangement of the pipette tips 2 in a first direction. The exact position of each support strip 16 in the depicted closed state is in turn adjusted or specified by way of a respective limit stop. In the present example, the limit stops for all the support strips are combined for the closed state and configured as a limit stop element 23 provided with pairs of steps.

(40) Movement of the support strips 16 is driven in a particular way, as is described further below with reference to FIGS. 10 to 13.

(41) Firstly, however, the next method step is explained with which the pipette tips 2 are likewise compactly arranged in a second direction. For this purpose, the handling system 1 is provided with a second grouping unit 24, which is depicted in FIG. 6 together with the first grouping unit 14. The second grouping unit 24 is located above the first grouping unit, because it is intended to receive the pipette tips 2, which are still located in the first grouping unit, therefrom.

(42) To this end, the second grouping unit 24 in turn also has eight support strips 25, which are mounted movably on pairs of guide rails. Here too, three pairs of guide rails 26, 27 and 28 are provided. The principle of operation of the second grouping unit 24 is largely identical to the principle of operation of the first grouping unit 14. There is a difference in that, in the first grouping unit 14, the pipette tips 2 are arranged within receiving openings of the support strips, while the second grouping unit 24 is set up so to speak to lift the pipette tips 2 in each case using a downwardly projecting receiving element 29 which extends into the opening of the pipette tip 2. The support strips 25 of the second grouping unit 24 are to this end arranged suspended on the associated pair of two guide rails, as can best be seen from FIG. 7. When the suspended support strips 25 are in the spread-out state, outer limit stops 30 are provided, which exactly define the position of the support strips 25. Moreover, the suspended support strips 25 are visible, with said downwardly projecting receiving elements 29, which in each case engage in the opening of the pipette tip 2.

(43) The suspended support strips 25 of the second grouping unit 24 are arranged in the handling system offset by 90 relative to the support strips of the first grouping unit 14. The grid arrangement of 88 pipette tips, already moved together compactly with the first grouping unit in one direction, is moved together compactly with the suspended support strips 25 in the second direction, as shown in FIG. 8. For this closed state of the suspended support strips 25, inner limit stops are also provided, which are likewise configured as an integral limit stop element 31. In this way, the precise end position of each support strip 25 is defined therefor.

(44) The 88 pipette tips moved together compactly in two directions are then delivered by the second grouping unit 24 into a finished part holder, as shown in FIG. 9. The finished part holder has further empty receiving spaces for pipette tips, such that further grid arrangements each of 88 pipette tips can be placed on the finished part holder with the handling system.

(45) How the movement of the support strips of the two grouping units is driven is described below with reference to FIGS. 10 to 13. By way of example, the functionality of the drive is explained with reference to the second grouping unit, which has suspended support strips. FIG. 10 shows a portion of the second grouping unit 24. The support strips 25 thereof are subdivided into two symmetrical sides, each with four of the support strips 25. An integral limit stop element 31 is provided for the closed state of the support strips and outer stops 30 are provided for the spread-out state. The outer limit stops 30 and the inner limit stop element 31 function in the same way as those explained with reference to FIGS. 4 and 5.

(46) FIG. 10 shows one symmetrical side of the second grouping unit, and reveals a pusher element 32, which is driven translationally by a pneumatic cylinder P1. The other symmetrical side is constructed as a mirror image, the pusher element used and the pneumatic cylinder being identical.

(47) FIG. 11 shows just the pusher element 32, which is set up in such a way that its movement can be transmitted to all four support strips 25 of the one symmetrical side. This takes account of the fact that all the support strips 25 have to be moved by different amounts. If the support strips 25 are moved to and fro between the spread-out and the closed states, then the inner support strip, which is closest to the midline C, has to travel the shortest distance and the outlying support strip, which is furthest from the midline C, has to travel the longest distance.

(48) When the support strips 25 move apart from the closed state into the spread-out state, once the first, inner support strip has reached its limit/end stop, the remaining three support strips 25 have to continue moving. Once the second support strip 25 has reached its end stop, the third and fourth support strips 25 have to continue moving, and as soon as the third support strip 25 reaches its limit/end stop, just the fourth support strip 25 continues moving on to its end stop.

(49) To implement the above-described movement of the support strips mechanically, adjoining movement paths 33a, 34a, 35a are provided with individual movement end points for the support strips, specifically in the form of pusher face pairs 33, 34, 35 and 36 respectively.

(50) The pusher faces of the pusher face pairs are in each case aligned facing one another and define the ends of the corresponding movement path. The movement paths are oriented parallel to the translational direction of movement of the pusher element 32.

(51) A driver element 37, which interacts with the associated pusher face pairs of the pusher element 32, is arranged on each support strip 25. Depending on the direction of movement, the driver element 37 is pushed by one or the other pusher face in the corresponding direction.

(52) For the outlying support strip 25, which has to travel the furthest distance between the spread-out and closed states, the pusher face pair is configured as a hole 36a in the pusher element 32. The two pusher faces lie close to one another in the hole. This is the case because the maximum stroke of the pusher element 32 corresponds to the distance by which the outlying support strip 25 has to be moved between the spread-out and the closed states.

(53) FIG. 12 shows the closed state of the four support strips 25. The inner one of the four support strips 25 lies against the midline C and the others are arranged compactly against one another.

(54) If more than four support strips are provided per symmetrical side, these may be moved using a correspondingly adapted pusher element, which has additional pusher face pairs for each additional support strip.

(55) FIG. 13 shows the support strips 25 of both symmetrical sides in the closed state and the position of the midline C. The respectively inner support strip 25 has been moved up to the midline C and the other support strips lie compactly next to one another. FIG. 13 shows the driver elements 37. Each driver element 37 is held in a hole 38 in the support strip 25, and has a driver foot 37a, which sits in the hole 38 and a driver head 37b, which projects from the support strip. The driver foot 37a is of yielding construction, so as to have an elastically resilient action. When the driver head 37b comes into contact with one of the pusher faces of the pusher element, the elastically resilient action is accompanied by a degree of damping. It is moreover possible, in this way, to move the support strips to their end positions against the respective limit stops (30, 31) and bring about a distinct end position. Due to the yielding nature of the driver elements 37, high pressure against the limit stops (30, 31) is avoided and on the other hand it may be ensured that the support strip 25 does not stop moving before reaching the limit stop (30, 31), with the attendant risk of imprecise positioning.

(56) FIGS. 14a to 14e are schematic representations of specific preferred removal assemblies, as may be specified by multi-cavity molds. Corresponding radial runner systems with mold cavities may specify such a removal assembly.

(57) According to FIG. 14a, a removal assembly is shown which is based on two radial runner systems 39 and 40 each with four mold cavities. The removal assembly is shown in a vertical plane. Here, injection molded parts from the two radial runner systems lie next to one another. The positions of the four mold cavities or injection molded parts 41 of a radial runner system are indicated by small circles, which are uniformly distributed about a circumcircle 42. According to FIG. 14a, the injection molded parts 41 are arranged square relative to one another. Each two injection molded parts 41 lie symmetrically relative to a vertical midline C. The two injection molded parts to the left of the midline C lie on an outer line and form a row R1 and the two injection molded parts to the right of the midline C lie on an outer line and form a row R2. Since this removal assembly already has two rows and identical numbers of injection molded parts 41 per row, the removal assembly here allows injection molded parts to be delivered directly into the first grouping unit.

(58) FIG. 14b shows a removal assembly which is likewise in a vertical plane, wherein this assembly is based on a radial runner system with six mold cavities or injection molded parts 43 which lie on a circumcircle 44. Each three injection molded parts 43 are arranged symmetrically relative to a vertical midline C. The midline C itself remains free of injection molded parts. The three mold cavities on one side of the midline C are not as yet arranged in a row. One injection molded part lies to the outside on the circumcircle and is at the greatest distance from midline C. The other two injection molded parts lie closer to the midline C. To produce a row arrangement, the two injection molded parts located closer to the midline C are pushed outward until they are in a vertical row R1 with the outlying injection molded part. The inner two injection molded parts to the right of the midline C are pushed into R2.

(59) In order to be able to bring about the above-described two-row arrangement of injection molded parts, the transfer unit is further developed. To this end, the transfer unit is provided with a repositioning device, which can modify the position of specific injection molded parts. A correspondingly further developed transfer unit or the repositioning device thereof is explained further below with reference to FIGS. 15 and 16.

(60) FIG. 14c shows a removal assembly, again in a vertical plane, wherein this assembly is based on a radial runner system with eight mold cavities or injection molded parts 45, which lie uniformly spaced on a circumcircle 46. According to the diagram of FIG. 14c, each four injection molded parts lie symmetrically relative to a vertical midline C. The midline C itself remains free of injection molded parts. The four injection molded parts on one side of the midline are not as yet arranged in a row. Two of the injection molded parts are already aligned to the outside in a row R1 and are at the greatest distance from the midline C. The other two injection molded parts lie closer to the midline C and are pushed outward until they are in the same row R1 as the other two outlying injection molded parts, so as to bring about a row arrangement. This happens in mirror image on the other side of the midline C. A grid arrangement of 24 injection molded parts in parallel rows is thus obtained, which may be delivered into the grouping unit.

(61) FIG. 14d shows a further removal assembly, again in a vertical plane, wherein this assembly is based on a radial runner system with ten mold cavities or injection molded parts 47, which lie uniformly spaced on a circumcircle 48. Each five injection molded parts lie symmetrically relative to a vertical midline C. The midline C itself again remains free of injection molded parts. The five injection molded parts on one side of the midline C are not as yet arranged in a row. One injection molded part is at the greatest distance from the midline. There are four other injection molded parts, two of which are a short distance from the midline C and the other two of which are a medium distance from the midline C. To bring about a row arrangement, the injection molded parts at a short and medium distance from the midline are all pushed outwards until they are in one and the same vertical row R1 as the outlying injection molded part and correspondingly symmetrically in one and the same vertical row R2. This results in a grid arrangement of 25 injection molded parts in parallel rows, which may be delivered into the grouping unit.

(62) FIG. 14e shows a further removal assembly, likewise in a vertical plane, wherein this assembly is based on a radial runner system with twelve mold cavities or injection molded parts 49, which lie uniformly spaced on a circumcircle 50. Each six injection molded parts lie symmetrically relative to a vertical midline. The midline itself again remains free of injection molded parts. The six injection molded parts on one side of the midline C are not as yet arranged in a row. Two outlying injection molded parts are at the greatest distance from midline C and are already located aligned on a line parallel to the midline. There are four other injection molded parts, two of which are a short distance from the midline C and the other two of which are a medium distance from the midline C. To bring about a row arrangement, the injection molded parts at a short and medium distance from the midline are all pushed outward until they are in one and the same vertical row R1 or respectively one and the same vertical row R2 as the two outlying injection molded parts. This results in a grid arrangement of 26 injection molded parts in parallel rows, which may be delivered into the grouping unit.

(63) FIG. 15 clarifies how a further-developed transfer unit is configured. This further-development is needed when the multi-cavity mold, which specifies the removal assembly, has a number of 6 injection molded parts per radial runner system, distributed around a circumcircle, or a number of 8, 10 or 12 injection molded parts distributed around a circumcircle. In these cases, the injection molded parts arrive in the transfer unit without as yet any two-row arrangement with identical numbers of injection molded parts per row. Arrangement in rows with identical numbers of injection molded parts per row is, however, a prerequisite to be able to transfer the injection molded parts into the first grouping unit.

(64) The transfer unit proposed above is therefore further developed and specifically provided with a specific repositioning device 51, which may change the spatial arrangement of the injection molded parts in order to bring them into a two-row arrangement. The present further developed transfer device is based on a removal assembly, which corresponds in principle to the example of FIG. 14c, because it can in each case accommodate eight injection molded parts uniformly spaced around a circumcircle 52. In FIG. 15, eight projecting receiving elements 53 are provided for each of the eight injection molded parts originating from one radial runner system. The repositioning device 51 can handle injection molded parts from a total of eight radial runner systems. In the transfer unit, the spatial arrangement of the eight radial runner systems is mapped in two rows, an upper row L1 and a lower row L2 each with four radial runner systems.

(65) A vertical midline C runs in each case through a radial runner system of the upper row L1 and a radial runner system of the lower row L2. Each radial runner system has four receiving elements 53 for injection molded parts provided in each case to the left of the midline C and likewise four receiving elements 53 for injection molded parts to the right of the midline C.

(66) The repositioning device has a base element 54. The receiving elements 53 for those injection molded parts which do not have to be shifted, namely the outlying receiving elements 53 located in rows R1 and R2, are arranged stationarily on the base element.

(67) Furthermore, the other four receiving elements of the repositioning device are mobile, namely those which, according to FIG. 15, are located closer to the midline C.

(68) To obtain the mobile receiving elements of the repositioning device, pusher rods 55, 56, 57, 58, 59, 60, 61 and 62 are provided, which are capable of pushing the mobile receiving elements. Those mobile receiving elements which are identically aligned and have to be moved in the same direction interact with the same pusher rod. This applies, for example, to the mobile receiving elements 59, 60, 61 and 62 in row L2, which interact with the pusher rod 61 and have to be moved in the direction of arrow M. However, mobile receiving elements 67, 68, 69 and 70 identically aligned in row L2 are also present which have to be moved in the opposite direction, that of arrow N, and for this purpose are connected with pusher rod 62, which is moved in the direction of arrow N.

(69) For the pusher rods 56, 58, 60 and 62, coupling is provided via a coupling element 71 which connects these pusher rods together and moves them in the same direction. One receiving element, with the same direction of movement, from each radial runner system is connected to each of these pusher rods. A pneumatic cylinder 72 is provided on the coupling element 71 for joint drive of the pusher rods 56, 58, 60 and 62.

(70) The other pusher rods 55, 57, 59 and 61 are likewise connected together via a coupling element 73 for the purpose of being jointly driven. A piston rod 74 of the pneumatic cylinder 72 is connected to the coupling element 73. For correct positioning of the receiving elements which are movable to and fro, limit stop elements are provided on the pusher rods, such as for example limit stop element 75 on pusher rod 56. One limit stop element is sufficient per pusher rod for each direction of movement. The limit stop element then interacts with one of the receiving elements of these pusher rods. None of the other receiving elements needs its own limit stop elements.

(71) FIG. 16 shows the final state, in which all the mobile receiving elements have been moved outward relative to the midline, such that now the limit stop element 75 has come into contact with the nearest receiving element of the pusher rod 56, thereby limiting movement in this direction. Furthermore, in FIG. 16, a second limit stop element 76 is provided on the pusher rod 56, which limits movement in the opposite direction. In the present exemplary embodiment, the limit stop element 76 interacts with two receiving elements, which move symmetrically toward one another and stop on both sides, when they come into contact with the limit stop element 76.

(72) In FIG. 15, the two receiving elements are in contact with the stated limit stop element 76; however, the perspective of FIG. 15 means that the limit stop element is concealed. The mobile receiving elements are then situated in one row R1 or R2 with the two outer stationary receptacles. In this way, a total of 88 injection molded parts have been repositioned from a virtually circular arrangement into a grid arrangement with parallel rows. As a result, eight vertical rows are formed, each row of which comprises four receiving elements. With this grid arrangement, a total of 64 injection molded parts may be delivered by the transfer unit into the first grouping unit.

LIST OF REFERENCE SIGNS

(73) 1 Handling system 2 Pipette tip 3 Injection molding machine 4 Multi-cavity mold 4a Mold part (stationary) 4b Mold part (mobile) 5 Finished part holder 6 Removal unit 7 Circumcircle 8 Circumcircle 9 Mandrel 10 Receiving opening (removal unit) 11 Linear guide 12 Linear motor 13 Transfer unit 14 First grouping unit 15 Transfer mandrel 16 Support strip 17 Receiving opening (support strip) 18 Guide rail (pair) 19 Guide carriage (pair) 20 Guide rail (pair) 21 Guide rail (pair) 22 Outer limit stop 23 Limit stop element 24 Second grouping unit 25 Support strip 26 Guide rail 27 Guide rail 28 Guide rail 29 Receiving element 30 Outer limit stop 31 Limit stop element 32 Pusher element 33 Pusher face pair 33a Movement path 34 Pusher face pair 34a Movement path 35 Pusher face pair 35a Movement path 36 Pusher face pair 36a Hole 37 Driver element 37a Driver foot 37b Driver head 38 Hole (support strip) 39 Radial runner system 40 Radial runner system 41 Injection molded part 42 Circumcircle 43 Injection molded part 44 Circumcircle 45 Injection molded part 46 Circumcircle 47 Injection molded part 48 Circumcircle 49 Injection molded part 50 Circumcircle 51 Repositioning device 52 Circumcircle 53 Receiving element 54 Base element 55 Pusher rod 56 Pusher rod 57 Pusher rod 58 Pusher rod 59 Pusher rod 60 Pusher rod 61 Pusher rod 62 Pusher rod 63 Receiving element 64 Receiving element 65 Receiving element 66 Receiving element 67 Receiving element 68 Receiving element 69 Receiving element 70 Receiving element 71 Coupling element 72 Pneumatic cylinder 73 Coupling element 74 Piston rod 75 Limit stop element 76 Limit stop element C Midline L1 Row L2 Row M Arrow N Arrow P1 Pneumatic cylinder R1 Row R2 Row S1 Mobile receiving element S2 Mobile receiving element S3 Mobile receiving element S4 Mobile receiving element P1