DEVICE AND METHOD FOR TRANSPORTING PREFORMS IN THE REGION OF A BLOW-MOLDING MACHINE

Abstract

The invention relates to devices and to methods for transporting preforms in the region of a blow-molding machine, in particular a sorting device (10) for transporting preforms (20) composed of a thermoplastic material in the region of a blow-molding machine for the blow-molding of containers, comprising a transportation wheel (12), which has a plurality of accommodating recesses (18) for accommodating and conveying the preforms (20), which accommodating recesses are arranged on the circumference of the transportation wheel in such a way that the accommodating recesses are distributed in the circumferential direction, a guide collar (16), which extends circumferentially around the transportation wheel (12) in some regions in such a way that the guide collar is radially spaced apart from the transportation wheel, wherein the preforms (20) are transported in suspension between the transportation wheel (12) and the guide collar (16) in the region of the sorting device (10), and a selection unit for selectively removing a respective individual preform (20) transported in one of the accommodating recesses (18) of the transportation wheel (12), wherein the selection unit comprises a pivotable ejecting star (14) with a plurality of ejecting arms (31), which ejecting star, when in the idle position, reaches into the peripheral region of the transportation wheel (12) by means of a first ejecting arm (31) immediately adjacent to the guide collar (16) in the transportation direction of the preforms (20), in such a way that the preforms (20) in the accommodating recesses (18) that are transported past the first ejecting arm (31) are secured against unintentionally falling out, wherein the ejecting star (14), in the event of a rotational motion, pushes an individual preform (20), which is marked for removal, out of one of the accommodating recesses (18) of the transportation wheel (12) by means of a second ejecting arm (32) following after the first ejecting arm (31), and wherein, in a recurring manner after the preform (20) marked for removal has been pushed out, the second ejecting arm (31) takes on the securing of the preforms (20) transported past the second ejecting arm against falling out of the accommodating recesses (18).

Claims

1. A sorting device for transporting preforms composed of a thermoplastic material in a region of a blow-molding machine for blow-molding the preforms into containers, comprising: a transportation wheel, which has a plurality of accommodating recesses for accommodating and conveying the preforms, which accommodating recesses are arranged on a circumference of the transportation wheel in such a way that the accommodating recesses are distributed in a circumferential direction; a guide collar, which extends circumferentially around the transportation wheel in some regions in such a way that the guide collar is radially spaced apart from the transportation wheel, wherein the preforms are transported in suspension between the transportation wheel and the guide collar in the region of the sorting device; and a selection unit for selectively removing a respective individual preform transported in one of the accommodating recesses of the transportation wheel; wherein the selection unit comprises a pivotable ejecting star with a plurality of ejecting arms, which ejecting star, when in the idle position, reaches into a peripheral region of the transportation wheel by means of a first ejecting arm immediately adjacent to the guide collar in a transportation direction of the preforms, in such a way that the preforms in the accommodating recesses that are transported past the first ejecting arm are secured against unintentionally falling out of the accommodation recesses, wherein the ejecting star, in the event of a rotational motion, pushes the individual preform, which is marked for removal, out of one of the accommodating recesses of the transportation wheel by means of a second ejecting arm following after the first ejecting arm, and wherein, in a recurring manner after the preform marked for removal has been pushed out, the second ejecting arm secures the preforms transported past the second ejecting arm against falling out.

2. The sorting device according to claim 1, wherein in the transportation direction of the preforms, immediately adjacent to the ejecting star, a second guide collar is spaced radially from the transportation wheel, such that the preforms that are secured during transportation against falling out by the idle ejecting arms are received from the ejecting star, and are transported further in suspension between the second guide collar and the transportation wheel in suspension, at least partially in the circumferential direction of the transportation wheel.

3. The sorting device according to claim 1, wherein an axis of rotation of the ejecting star and an axis of rotation of the transportation wheel lie in planes that are at an angle with respect to each other.

4. The sorting device according to claim 1,wherein the ejecting star has at least three ejecting arms, wherein each of said at least three ejecting arms has a guide segment with a holding section for securing one of said preforms transported in the holding section of said ejecting star.

5. The sorting device according to claim 1,wherein the ejecting star has at least three ejecting arms, wherein each of said at least three ejecting arms has a guide segment with an ejection section for ejecting one of said preforms transported in the election section of said ejecting star.

6. The sorting device according to claim 1, wherein rotational movement of the ejecting star is synchronized with rotational movement of the transportation wheel.

7. A method for feeding preforms composed of a thermoplastic material to a blow-molding machine for blow molding the preforms into containers, wherein lined up and aligned preforms are transferred to a first separation unit having a sorting device for sorting individual preforms, wherein the preforms in the separation unit are inspected by means of an inspection device, and wherein the preforms are subsequently transferred to an accumulation segment configured to hold and/or to close gaps resulting from removals of preforms.

8. The method according to claim 7, wherein the separating unit comprises a transportation wheel which transfers the preforms to the inspection device and then to a selection unit of the sorting device for selective removal, prior to transfer of the preforms to the accumulation segment.

9. The method according one of claim 7, wherein the accumulation segment comprises a conveyor having a transportation line, and wherein the preforms are transported along the transportation line in a substantially horizontal direction.

10. The method according to claim 7, wherein a feed force for transportation of the preforms along the accumulation segment is generated by means of compressed air flow.

11. The method according to claim 7, wherein the preforms in region of the sorting device are inspected by means of the inspection device contactlessly for material irregularities.

12. The method according to claim 7, wherein the sorting device comprises: a transportation wheel, which has a plurality of accommodating recesses for accommodating and conveying the preforms, which accommodating recesses are arranged on a circumference of the transportation wheel in such a way that the accommodating recesses are distributed in a circumferential direction; a guide collar, which extends circumferentially around the transportation wheel in some regions in such a way that the guide collar is radially spaced apart from the transportation wheel, wherein the preforms are transported in suspension between the transportation wheel and the guide collar in the region of the sorting device; and a selection unit for selectively removing a respective individual preform transported in one of the accommodating recesses of the transportation wheel; wherein the selection unit comprises a pivotable electing star with a plurality of electing arms, which electing star, when in the idle position, reaches into a peripheral region of the transportation wheel by means of a first electing arm immediately adjacent to the guide collar in a transportation direction of the preforms, in such a way that the preforms in the accommodating recesses that are transported past the first ejecting arm are secured against unintentionally falling out of the accommodation recesses, wherein the ejecting star, in the event of a rotational motion, pushes the individual preform, which is marked for removal, out of one of the accommodating recesses of the transportation wheel by means of a second electing arm following after the first electing arm, and wherein, in a recurring manner after the preform marked for removal has been pushed out, the second ejecting arm secures the preforms transported past the second ejecting arm against falling out.

13. The method according to claim 7, wherein the preforms coming from the accumulation segment are transferred to a second separation unit and transported individually without gaps after successful separation.

14. A transportation device for feeding preforms to a blow-molding machine for blow molding containers made from thermoplastic material, wherein the transportation device is configured and equipped to perform a method according to claim 7.

15. A transportation device according to claim 14, wherein the transportation device comprises a sorting device comprising: a transportation wheel, which has a plurality of accommodating recesses for accommodating and conveying the preforms, which accommodating recesses are arranged on a circumference of the transportation wheel in such a way that the accommodating recesses are distributed in a circumferential direction; a guide collar, which extends circumferentially around the transportation wheel in some regions in such a way that the guide collar is radially spaced apart from the transportation wheel, wherein the preforms are transported in suspension between the transportation wheel and the guide collar in the region of the sorting device; and a selection unit for selectively removing a respective individual preform transported in one of the accommodating recesses of the transportation wheel; wherein the selection unit comprises a pivotable electing star with a plurality of electing arms, which electing star, when in the idle position, reaches into a peripheral region of the transportation wheel by means of a first electing arm immediately adjacent to the guide collar in a transportation direction of the preforms, in such a way that the preforms in the accommodating recesses that are transported past the first electing arm are secured against unintentionally falling out of the accommodation recesses, wherein the electing star, in the event of a rotational motion, pushes the individual preform, which is marked for removal, out of one of the accommodating recesses of the transportation wheel by means of a second ejecting arm following after the first ejecting arm, and wherein, in a recurring manner after the preform marked for removal has been pushed out, the second electing arm secures the preforms transported past the second electing arm against falling out.

16. A blow-molding machine for blow molding containers from preforms made of a thermoplastic material into containers, wherein the blow-molding machine comprising a sorting device comprising a transportation device according to claim 14.

17. The method according to claim 11, wherein contactless inspection of the preforms for material irregularities is performed optically in the region of the sorting device.

Description

[0066] FIG. 1 shows an isometric view of a sorting device 10 according to the invention with a transportation wheel 12 rotating in a plane, and with an ejecting star 14 arranged on the perimeter of the transportation wheel 12. The ejecting star 14 is mounted on a rotational axis and rotates in a plane at an angle, or specifically, perpendicularly to the rotation plane of the transportation wheel 12.

[0067] In the variant shown, the transportation wheel 12 is sectionally surrounded by a guide collar 16. The transportation wheel 12 has pocket-like accommodation recesses 18, which are designed for accommodating and transporting preforms 20. In the variant shown, preforms 20 are transported in free suspension between the guide collar 16 and the transportation wheel 12 in the circumferential direction of the transportation wheel 12. For that purpose, the preforms 20 are forcibly moved in the direction of rotation of the transportation wheel 12 by trailing edges of the pocket-shaped molded accommodation recesses 18.

[0068] The preforms 20 are transferred to the transportation wheel 12 in a lead-in region 22 exemplarily shown in FIGS. 2 and 4, and after this transfer they are transported further in free suspension between the guide collar 16 and the transportation wheel 12 on a retaining collar positioned below their outflow region.

[0069] In the variant of the sorting device 10 shown here, the guide collar 16 is embodied as an arc segment, with a trailing edge 24 and a leading edge 26 when viewed in the direction of rotation of the transportation wheel 12. Immediately after the leading edge 26, the guide collar 16 is followed by the ejecting star 14. The ejecting star 14, which rotates in the variant shown in a plane perpendicular to the plane defined by the transportation wheel 12, features ejecting arms 14 with guide segments 28, which are plate-shaped in the variant shown. The guide segments 28 each have a holding section 30 which secures the preforms 20 after their transfer from the guide collar 16 against falling out of the accommodation recess 18 of the transportation wheel 12, and which continues in the variant shown in the circumferential direction of the transportation wheel 12. In the present case, the holding section 30 is approximately collar-shaped, and when it supports the preforms 20 in a idle position, it complements the guide collar 16 in the region of the ejecting star 14.

[0070] The guide segment 28 with the holding section 30 is fastened to an ejecting arm 32 of the ejecting star 14. As shown, the guide segment 28 may be formed as a plate which is transversely, or specifically: perpendicularly attached to the ejecting arm 32 in a radial direction. In addition to a holding section 30 which secures the preforms 20 against unintentionally falling out of the accommodation recess 18, the guide segment 28 may also feature an ejection section 32.

[0071] When the ejecting star 14 is rotated, the guide segment 28 with the holding section 30 moves outward in a radial direction of the transportation wheel 12, and releases a preform 20 that had previously been secured by the holding section 30 for ejection.

[0072] In the illustrated variant, an edge of the ejection section 32 moving in the rotational direction of the ejecting star 14 pushes the preform 20 that was released at the holding section 30 radially outward, away from the transportation wheel 12.

[0073] A guide rail 34 arranged downstream from the ejecting star 14 accepts the preforms 20 transported by the transportation wheel 12 and leads them away from the transportation wheel 12 for onward transportation.

[0074] FIG. 2 shows a top view of the sorting device 10 of FIG. 1 with an inspection device 38 arranged in the region of the transportation wheel 12 for detecting preforms 20 unsuitable for the blow molding process, and a lead-in region 22 serving for the transfer of the preforms 20 to the transportation wheel 12. In FIG. 2, a second guide collar segment 16′ is shown, which is arranged downstream, immediately behind the ejecting star 14, when viewed in the transportation direction of the preforms 20. When the ejecting star 14 is in its idle position, the gap between the guide collar segments 16 and 16′ allows for an uninterrupted transportation of preforms 20 from the guide collar segment 16 to the guide collar segment 16′ is possible. As long as no ejection of a preform 20 is occurring, the guide segment 28 of the ejecting star 14 with the holding section 30 supports the preforms 20 transported in the accommodation recesses 18—at least in the variant shown here. The gap filled by the ejecting star 14 with the guide segment 28 between the guide collar segments 16 and 16′ has at least the width of a preform 20. In particular, the distance between the sections 16 and 16′ corresponds at the most to the mean distance between two consecutive accommodation recesses 18 of the transportation wheel 12. The direction of rotation of the transportation wheel 12 envisioned for the transportation of the preforms 20 is shown by the arrow T.

[0075] FIG. 3 is a sectional view of the sorting device 10 along the line 3-3 in FIG. 2. The preform 20 is clearly visible, freely suspended between the guide segment 28 of the ejecting star 14 and the peripheral region of the transportation wheel 12 from a retaining collar below the outflow region of the preform 20. As clarified by the sectional view and as can be seen in comparison with FIG. 1, the preform 20 is contacted for the transportation along the transportation wheel 12 by a trailing edge of the accommodation recess 18, and forcibly moved during the rotation of the transportation wheel 12 in the circumferential direction. The direction of rotation of the ejecting star 14 is indicated by the arrow A.

[0076] Below the transportation wheel 12, a drive 40 for the transportation wheel 12 is shown. As shown, the transportation wheel drive 40 may be used as a drive or as a supporting mounting for the transportation wheel 12.

[0077] As can be clearly seen in FIG. 3, the ejecting star 14 has several ejecting arms 32 which extend radially outward from the axis of rotation of the ejecting star 14. At the end segment of each radially outward oriented ejecting arm 32, a guide segment 28 is arranged with an ejection section 32 extending in the direction of rotation of the ejecting star 14, and with a trailing holding section 30. The ejection section 32 and/or the holding section 30 can each be formed by edges pointing in the circumferential direction of the transportation star 14.

[0078] In FIG. 3 it can be clearly seen that for the ejection of a preform 20 through the rotation of the ejecting star 14, first the holding section 30 is directed radially outward and moved away from the transportation wheel following the circular movement of the ejecting arm 32, upon which the preform 20 is ejected by the ejection section 32 of the transportation wheel 12.

[0079] FIG. 4 is an isometric view of the sorting device 10 with the inspection device 32 and the lead-in region 22 of FIG. 2.

[0080] FIG. 5 shows a highly schematically representation of a transportation device with an inventive sorting device 10. Illustrational details were not shown here for reasons of clarity. In this figure, a lead-in region 22 is shown, in which preforms 20 are transferred, for instance, to a sorting device 10 according to the invention. The lead-in region 22 receives aligned successive preforms from a lead-in rail 21, which is located upstream from the lead-in region 22 in the transportation direction of the preforms 20. Downstream from the lead-in region 22, the preforms 20 are transferred to the transportation wheel 12 of the sorting device 10. The preforms 20 are transported by the rotation of the transportation wheel 12 in the region of the sorting device 10 in the circumferential direction of the transportation wheel 12, in suspended between the transportation wheel 12 and a guide collar 16. The preforms can be accommodated in pocket-shaped recesses on the periphery of the transportation wheel 12 (not shown). Details of the transportation device, in particular of individual components, can be embodied as explained for the preceding figures.

[0081] An inspection device 38 inspects the preforms 20 transported on the transportation wheel 12. Upon detection of preforms 20 unsuited for further processing or for further transportation, an inventive ejecting star 14 is controlled such that the preforms 20 identified as unsuitable are individually removed or ejected from the transportation flow of the preforms 20.

[0082] When individual preforms 20 are discarded, gaps 46 are formed in the transportation flow, which must be filled before the transfer to the blow-molding machine. In the variant shown here, it is proposed that in order to fill the gaps 46, an accumulation segment 42 be added downstream from the sorting device 10. The accumulation segment may, for instance, be constructed as an air conveyor. In a conceivable alternative, the accumulation segment 42 may be constructed as an at least partially horizontal and/or sloping feed rail. The accumulation segment 42 is followed by a further lead-in region 22, which receives the preforms 20 and transfers them to a separation device 44. Details about a conveyor device used in the accumulation segment may be embodied as described in the documents WO 2006/058512 and/or DE 10 2010 028 500 A1. For configuration details, reference is made expressly to these documents.

[0083] By means of the separation device 44, the preforms 20 are separated for further transportation in the region of a blow-molding machine, for instance for being fed into a heating segment. One possibility might be, for instance, that the preforms 20 be transferred to a lead-out region 50 in the region of the separation device 44, in particular of a transportation wheel associated with a separation device, which then transfers the preforms 20 sequentially to an individual conveyor line 48. Details of the shown transportation wheel of the separation device 44 can be embodied like the transportation wheel 12 of the sorting device 10. In the variant shown, there is a purely schematic indication that the individual conveyor line 48 can be embodied as a circulating belt with attached conveyor forks for the transporting of separated preforms 20. In addition, other commonly used conveyor lines for the transportation of individual preforms 20 are conceivable as well.

[0084] The transportation device shown here makes it possible to sort out preforms 20 that are identified as unsuitable, and it provides for the closure of the gaps 46 resulting from the removal of preforms 20, so that a continuous and uninterrupted transportation flow of preforms 20 to a blow-molding machine, in particular to a heating device of a blow-molding machine is possible despite the reduced device complexity

[0085] List of Reference Numbers

[0086] 10 Sorting device

[0087] 12 Transportation wheel

[0088] 14 Ejecting star

[0089] 16 Guide collar

[0090] 18 Accommodation recess

[0091] 20 Preform

[0092] 21 Lead-in rail

[0093] 22 Lead-in region

[0094] 24 Guide collar trailing edge

[0095] 26 Guide collar leading edge

[0096] 28 Guide segment

[0097] 30 Holding section

[0098] 31 Ejecting arm

[0099] 32 Ejection section

[0100] 34 Guide rail

[0101] 36 Ejection drive

[0102] 38 Inspection device

[0103] 40 Transportation wheel drive

[0104] 42 Buffer zone

[0105] 43 First separation unit

[0106] 44 Second separation unit

[0107] 46 Gap

[0108] 48 Individual transportation line

[0109] 50 Lead-out region

[0110] T Rotational direction of the supporting wheel

[0111] A Rotational direction of the ejecting star