Device for Steadying Plastics Containers

Abstract

A device for steadying parisons for plastics containers, in particular PET bottle parisons, in the entry region of an entraining device of an inspection unit having an overlaid part that has at least a first functional portion and a second functional portion. The second functional portion is arranged downstream of the first functional portion. The first functional portion damps, in particular, vertical disruptive movements of a parison that has been taken up by the entraining device such that the second functional portion comes into a substantially form-fitting guiding engagement with the parison, this guiding engagement bringing about complete steadying of the parison.

Claims

1. A device for steadying parisons for plastics containers, in particular PET bottle parisons, in the entry region of an entraining device (1) of an inspection unit, comprising: an overlaid part (10) that has at least a first functional portion (11a) and a second functional portion (11b), wherein the second functional portion (11b) is arranged downstream of the first functional portion (11a), wherein the first functional portion (11a) damps in particular vertical disruptive movements of a parison (2) that has been taken up by the entraining device (1) such that the second functional portion (11b) comes into a substantially form-fitting guiding engagement with the parison (2), this guiding engagement bringing about complete steadying of the parison (2).

2. The device as claimed in claim 1, wherein the overlaid part (10) has a cover plate (12) that extends over the first and the second functional portion (11a, 11b).

3. The device as claimed in claim 1, wherein the cover plate (12) has a length (L) that corresponds to at least twice the support ring diameter (D.sub.T) of a parison (2) and a width (B) that corresponds at least to once the width of the support ring diameter (D.sub.T).

4. The device as claimed in claim 1, wherein two side walls (13) jut from the cover plate (12), in particular in the region of the second functional portion (11b), and preferably each have at their lower end an inwardly directed projection (14), such that the second functional portion (11b) has a cross section substantially in the shape of a C-profile.

5. The device as claimed in claim 4, wherein the inwardly directed projections (14) jut substantially horizontally from the side walls (13).

6. The device as claimed in claim 4, wherein the side edges (14a) of the projections (14) run parallel to the side walls (13), or they have a curvature.

7. The device as claimed in claim 1, wherein there is arranged, at least on a side wall (13) of the overlaid part (10), a mounting portion (15) by means of which the overlaid part (10) may be secured to a guide device (3) of the inspection unit.

8. The device as claimed in claim 7, wherein the mounting portion (15) has a bore (15b) for a securing device (15a).

9. The device as claimed in claim 7, wherein the mounting portion (15) has on its underside a three-point bearing (16).

10. The device as claimed in claim 9, wherein the three-point bearing (16) is constructed such that in the mounted condition the inwardly directed projections (14) of the side walls (13) jut by means of their underside from the upper side of the guide device (3) of the inspection unit, wherein preferably the corresponding spacing (A) corresponds at least to the thickness of the support ring (2a) of a parison (2).

11. The device as claimed in claim 1, wherein the cover plate (12) has a shoulder (17) on its underside, in the region of the second functional portion (11b), wherein the spacing from the mouth opening (2b) of the parison (2) to the underside of the cover plate (12) is larger in the region downstream of the shoulder (17) than in the region upstream of the shoulder (17).

12. The device as claimed in claim 1, wherein the cover Plate (12) has a chamfer (18) on its underside, in particular in the region of the first functional portion (11a).

13. The device as claimed in claim 1, wherein the overlaid part (10) is milled out of a block.

14. The device as claimed in claim 1, wherein the cover plate (12) has a viewing opening (19).

15. The device as claimed in claim 1, wherein the entraining device includes a star wheel (1).

Description

[0025] In the drawings:

[0026] FIG. 1 shows a detail view comprising an inspection unit having a device according to the invention that is arranged in the entry region of the star wheel;

[0027] FIG. 2 shows a perspective view of a device according to the invention;

[0028] FIG. 3 shows a front view of a device according to the invention, according to FIG. 2;

[0029] FIG. 4 shows a sectional view of the device according to the invention, along the line A-A according to FIG. 3;

[0030] FIG. 5 shows a bottom view of a device according to the invention, according to FIG. 2; and

[0031] FIG. 6 shows a top view of a device according to the invention, according to FIG. 2.

[0032] FIG. 1 shows a detail view comprising an inspection unit having an overlaid part 10 according to the invention that is arranged in the entry region of the star wheel 1. The parisons 2 are transported to the star wheel 1 of the inspection unit by way of a feed device 4 (that is to say, typically a feed rail) and are taken up there by a corresponding transport cutout 6 in the star wheel 1. The feed device 4 may moreover be converted to other sizes of parison by way of the likewise illustrated adjusting device 5.

[0033] The overlaid part 10 according to the invention is typically arranged very close to the point at which the parisons 2 enter the star wheel 1, in order to steady them as soon as possible for the camera of the inspection unit (which is not illustrated), which is arranged (relatively close) downstream. As can be seen, approximately two parisons 2 pass through the overlaid part 10 at the same time. By means of a mounting portion 15 and a corresponding securing device, the overlaid part 10 is arranged on a guide device 3 (typically a guide rail) on which there is guided a part of the support ring 2a of each parison 2 that does not lie on the upper side of the transport cutout 6.

[0034] The diameter D.sub.T of the support ring 2a is, as is conventional, larger than that of the mouth opening 2b of the parison 2. The guide rail 3 has a peripheral curvature that corresponds to that of the star wheel 1. The guide rail 3 is mounted, for example by means of screws 7, on a frame part of the inspection unit, it being possible to convert the guide rail 3 to another size of parison, similarly to the feed device 4. The arrow T moreover indicates the direction of transport.

[0035] The overlaid part 10 according to the invention is illustrated more closely in FIG. 2. From left to right, that is to say as seen in the direction of transport T, there are visible first the cover plate 12 with the entry edge 24 (cf. also FIG. 4), the chamfer 18 and the horizontal underside 20 adjoining it (or the outer part thereof that extends as far as the side walls 13) of the cover plate 12. This portion of the overlaid part 10 comprises the first functional portion 11a, which brakes or damps in particular initially vertical disruptive movements (that is to say wobbling or vibrational movements caused in particular by impact at relatively high transport speeds) of a parison 2 that has been taken up by the entraining device (that is to say that is coming from the feed device 4) by providing, in the vertical direction for the parison 2 or the mouth thereof, play that becomes smaller and smaller until it reaches the horizontal underside 20 and finally, in the horizontal region of the underside 20, remains at an initially constant small size (for example in the region of a few millimeters or even a few tenths of a millimeter).

[0036] The side walls 13, which jut vertically downward from the cover plate 12 and have the inwardly directed projections 14, then form the second functional portion 11b of the overlaid part 10 according to the invention. Here, the parison 2 comes into a substantially form-fitting guiding engagement that has the effect of holding the parison 2 completely down or steady. The guiding engagement for the parison 2 or the support ring 2a thereof is, in the present case, constructed between the undersides of the projections 14 and the upper side of the guide rail 3 (cf. FIG. 1).

[0037] Provided on a side wall 13 of the overlaid part 10 (that is to say preferably on the outwardly directed side wall 13) is the block-shaped mounting portion 15, which may be mounted adjustably on the guide rail 3 by means of the mounting or elongate bore 15b and a suitable securing device. Provided on the underside of the mounting portion 15 is a three-point bearing 16. In the region of the second functional portion 11b, the cover plate 12, the side walls 13 and the projections 14 define the interior space 22 through which the mouths of the parisons 2 (that is to say the portions above the support ring 2a) pass.

[0038] FIG. 3 illustrates a front view of the overlaid part 10 according to the invention, according to FIG. 2. The cover plate 12 and the side walls 13 that jut therefrom and have the inwardly directed projections 14 define the interior space 22, as stated above. Moreover, in the upper region of the interior space 22 there is visible a shoulder 17, whereof the purpose will be explained in more detail below in conjunction with FIG. 4. In the central region of the cover plate 12 there is also arranged an opening 19. This may be a viewing opening for monitoring operation, or indeed a threaded bore for attaching further structural elements or for further securing of the overlaid part 10.

[0039] Once again, the mounting portion 15 is visible, with the elongate bore 15b and the three-point bearing 16 that is arranged on its underside, for twist-free mounting of the overlaid part 10 on the guide rail 3. The side edges 14a of the projections 14 are conventionally constructed to be perpendicular, as can be seen. They ensure lateral guidance of the parisons (that is to say in the region of the mouth, above the support ring 2a) and moreover contribute to damping or suppressing lateral disruptive and rotary movements.

[0040] FIG. 4 illustrates a sectional view of the overlaid part according to the invention along the line A-A according to FIG. 3. Here there is again visible the construction of the first functional portion 11a, with the chamfer 18 (cf. FIG. 2), which forms an angle a of between 10 and 45, preferably between 15 and 40 and further preferably between 20 and 35. The transition from the first functional portion ha to the second functional portion 11b typically takes place at the point where the side walls 13 jut from the horizontal underside 20 of the cover plate 12. As can be seen, however, the horizontal underside 20 also extends somewhat further into the region of the second functional portion 11b, by about to of the overall length of the second functional portion 11b. At the point at which the horizontal underside 20 ends there is a shoulder 17, which gives the parison 2 and its mouth opening more play (that is to say by comparison with the horizontal underside of the cover plate 21 downstream of the shoulder 17) than before.

[0041] This serves the purpose of ensuring that when the parison 2 leaves the overlaid part 10 it does not catch by means of its mouth or its mouth opening 2b on the exit edge 23 of the cover plate 12 at the end of the second functional portion 11b and cause the parison 2 to tilt and possibly strike against the upstream or downstream parisons 2. By means of the shoulder 17, disruptions to operation of this kind can be reliably avoided. The horizontal underside of the cover plate 21 downstream of the shoulder 17 is typically somewhat longer than the diameter D.sub.T of the support ring 2a of a parison 2.

[0042] In the region downstream of the shoulder 17, the thickness D of the cover plate 12 is only around half the thickness it had in the region of the horizontal underside 20. Moreover, again visible is the opening 19, constructed as a threaded bore, and the side edge 14a of the projection 14 that juts inward from the side wall 13.

[0043] On the underside of the mounting block 15 there is again visible the three-point bearing 16 and the spacing A that is formed by the three-point bearing from the underside of the projection 14. This spacing A is dimensioned such that there may be formed with the support ring 2a of a parison 2 a substantially form-fitting guiding engagement that on the one hand reliably and entirely holds down or steadies the parison and on the other hand causes no jamming or wedging of the parison 2 during transport. An additional three-point bearing 16 (or a corresponding support) may where applicable also be provided on the underside of the opposing side wall 13.

[0044] FIG. 5 shows a bottom view of an overlaid part 10 according to the invention. Visible here are the dimensions of the cover plate 12, namely the length L and the width B. The ratio L:B is preferably around 5:2, particularly preferably around 5:3 and yet further preferably 5:4. Moreover, FIG. 5 shows that the projections 14 or the side edges 14a of the projections 14 may take a curved line. This line typically follows the peripheral curvature of the star wheel 1 and the guide rail 3 and where applicable serves to ensure unhindered passage of the parison 2 through the overlaid part 10. Finally, FIG. 6 shows a corresponding top view of an overlaid part 10 according to the invention, with curved projections 14 or side edges 14a.

[0045] In the present description, moreover, like reference numerals designate the same components throughout.

LIST OF REFERENCE NUMERALS

[0046] 1 Entraining device (star wheel)

[0047] 2 Parison

[0048] 2a Support ring

[0049] 2b Mouth opening

[0050] 3 Guide device (guide rail)

[0051] 4 Feed device

[0052] 5 Adjusting device

[0053] 6 Transport cutout (of star wheel)

[0054] 7 Screw

[0055] 10 Overlaid part

[0056] 11a First functional portion

[0057] 11b Second functional portion

[0058] 12 Cover plate

[0059] 13 Side walls

[0060] 14 Projections

[0061] 14a Side edges

[0062] 15 Mounting portion

[0063] 15a Securing device

[0064] 15b Mounting bore

[0065] 16 Three-point bearing

[0066] 17 Shoulder

[0067] 18 Chamfer

[0068] 19 Viewing opening

[0069] 20 Horizontal underside of cover plate (upstream of shoulder)

[0070] 21 Horizontal underside of cover plate (downstream of shoulder)

[0071] 22 Interior space

[0072] 23 Exit edge

[0073] 24 Front edge (entry edge)

[0074] A Spacing

[0075] B Width

[0076] D Thickness

[0077] D.sub.T Diameter of support ring

[0078] L Length

[0079] T Direction of transport

[0080] Angle of chamfer