DEVICE FOR TESTING A CONNECTION OF A GUARANTEE STRIP OF A SECURITY SEAL OF A CLOSURE LID HAVING A LID MAIN BODY

Abstract

The invention relates to a device (100) for testing a connection of a guarantee strip (3.1) of a security seal of a closure lid (1.1) having a lid main body (2.1), which device comprises a driver element (180) for gripping the guarantee strip (3.1) and a stop element (780) for the lid main body (2.1). The driver element (180) and the stop element (170) are movable relative to each other such that a tear-off force can be exerted on the guarantee strip (3.1). The device (100) also comprises a force-measuring device (171), for measuring the tear-off force during the relative movement of the guarantee strip (3.1) and the lid main body (2.1), and a separating device (191, 192) for severing the guarantee strip (3.1) after it has been tom off from the lid main body (2.1). This allows the guarantee strip (3.1) to be severed and thereby results in a considerable simplification of the removal of the guarantee strip (3.1) from the testing device, in particular if the testing device is designed such that the tom-off guarantee strips (3.1) are slid onto the stop element (170). The device (100) can be operated in a fully automatic manner and can be integrated in a system for producing closure lids having guarantee strips.

Claims

1. A device for testing a connection of a guarantee strip of a security seal of a closure lid having a lid main body, comprising a) a take-along element for gripping the guarantee strip; b) a stop element for the lid main body, wherein the take-along element and the stop element are movable relative to each other in such a manner that a tear-off force can be exerted on the guarantee strip and wherein the stop element is formed on the end side of a mandrel; c) a force-measuring device for measuring the tear-off force during the relative movement of the guarantee strip and the lid main body; d) a cutting device for severing the guarantee strip, wherein e) the take-along element surrounds the mandrel in a sleeve-shaped manner and is movable linearly relative to the mandrel along a longitudinal direction of the mandrel; and e) the cutting: device is adapted to severing the guarantee strip after the latter has been torn off from the lid main body.

2. (canceled)

3. The device as claimed in claim 1, wherein the cutting device comprises at least one slitting knife which is arranged in the circumferential region of the mandrel and is designed in such a manner that the guarantee strip is severed as it moves over the slitting knife, along the longitudinal direction of the mandrel.

4. The device as claimed in claim 3, wherein the cutting device comprising at least two slitting knives which are arranged in such a manner that the guarantee strip is severed at two circumferentially spaced-apart points.

5. The device as claimed in claim 3, wherein the sleeve-shaped take-along element having at least one groove in the longitudinal direction of the mandrel, said groove interacting with the at least one slitting knife.

6. The device as claimed in claim 1, wherein the longitudinal direction of the mandrel has an angle of at least 30° with respect to a horizontal plane, wherein a movement in the longitudinal direction of the mandrel for measuring the tear-off force takes place upward and wherein the device comprises a collecting apparatus for the lid main body and the torn-off guarantee strip, said collecting apparatus being movable below the mandrel temporarily into a collecting position.

7. The device as claimed in claim 6, wherein the collecting apparatus having a collecting surface which is inclined in the collecting position, and therefore the collected lid main body and the collected guarantee strip are automatically conveyed further owing to gravity.

8. The device as claimed in claim 7, wherein the longitudinal direction of the mandrel has an inclination of 10-80° with respect to the horizontal plane and in that the supporting surface of the collecting apparatus in the collecting position is perpendicular to the longitudinal direction of the mandrel.

9. The device as claimed claim 6, wherein the collecting apparatus is movable into the collecting position by rotation about an axis parallel to the longitudinal direction of the mandrel.

10. The device as claimed in claim 1, further comprising an evaluation unit for receiving measurement values of the measurements of the tear-off force, for determining with reference to said measurement values whether the connection of the guarantee strip to the lid main body meets predetermined properties and for outputting results of this determination.

11. The device as claimed in claim 10, wherein it can be determined by the evaluation unit with reference to a plurality of received measurement values for the same connection whether one of a plurality of bridges of the connection has a considerably reduced or increased tear-off force in comparison to other bridges of the connection.

12. The device as claimed in claim 1, comprising d) a feed apparatus for automatically feeding the closure lid to the take-along element and to the stop element; and e) an outfeed apparatus for automatically removing the lid main body and the torn-off guarantee strip from the take-along element and/or the stop element.

13. An installation for slitting a guarantee strip for the security seal of a closure lid, comprising a slitting apparatus for producing circumferential cuts in order to form the guarantee strip on a lid main body of the closure lid; a device as claimed in claim 12, which is arranged downstream of the slitting apparatus, for testing a connection of the guarantee strip to the lid main body, wherein the closure lid is automatically fed by the slitting apparatus to the device for testing.

14. The installation as claimed in claim 13, comprising a device as claimed in claim 12, wherein the evaluation unit is coupled in terms of signals to a control apparatus of the installation such that the results of the determination can be transmitted to the control apparatus.

15. The installation as claimed in claim 14, wherein the control apparatus is designed in such a manner that a processing parameter of the slitting apparatus, in particular a temperature of a slitting knife of the slitting apparatus, can be influenced according to the transmitted results.

16. The installation as claimed in claim 14, wherein a tested closure lid is assigned to a part-tool of the slitting apparatus, which part-tool has interacted with the closure lid during the slitting of the guarantee strip, and/or to a cavity of an injection mold such that malfunctions determined with reference to the measurements of the tear-off force can be assigned to said part-tool and/or to the cavity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In the drawings used for explaining the exemplary embodiment:

[0050] FIG. 1 shows a schematic depiction of a closure lid with a guarantee strip;

[0051] FIG. 2 shows a first oblique view of a device according to the invention for testing the connection of the guarantee strip to the lid main body;

[0052] FIG. 3 shows a second oblique view of the device;

[0053] FIG. 4 shows a cross-sectional illustration of the mandrel, the take-along sleeve and the slitting knife;

[0054] FIG. 5 shows an oblique image of the take-along sleeve;

[0055] FIG. 6-10 show schematic illustrations of the device according to the invention for explaining the testing method carried out with the device;

[0056] FIG. 11 shows a force-displacement diagram of a testing operation; and

[0057] FIG. 12 shows a block diagram of an installation for producing guarantee strips with a testing device according to the invention.

[0058] In principle, identical parts are provided with the same reference signs in the figures.

Ways for Implementing the Invention

[0059] FIG. 1 shows a schematic depiction of a closure lid with a guarantee strip. The closure lid 1 comprises a lid main body 2, which is formed from a circular-cylindrical casing 2a and a base 2b, and a guarantee strip 3 with a strip-shaped part which is connected to the casing 2a of the lid main body 2 via a plurality of bridges 3a. The strip-shaped part is inwardly thickened, thus resulting in an undercut behind the strip-shaped part in the direction of the base 2b. In connection with the described exemplary embodiment, it is assumed that the closure lid 1 is produced from plastic (in particular polyethylene PE or polypropylene PP) and, in a manner known per se, has an internal thread for screwing onto a bottle, in particular a beverage bottle made from PET or glass. The closure lid 1 is manufactured by injection molding, the guarantee strip 3 is produced subsequently by slits 3b being introduced between the remaining bridges 3a by means of a slitting apparatus, and by a lower section of the strip-shaped part being folded up inward, thus resulting in the thickening.

[0060] The invention can also be used with different types of lids, for example with those made from metal sheet or with those in which the guarantee strip is already formed during the injection molding without an additional slitting process.

[0061] FIG. 2 shows a first oblique view of a device according to the invention for testing the connection of the guarantee strip to the lid main body, and FIG. 3 shows a second oblique view from the opposite side.

[0062] The testing device 100 comprises a base plate 101 on which a feeder 110, an outfeed 120 and a testing unit 150 in between are arranged. The feeder 110 comprises a base part 111 which is arranged obliquely with respect to the baseplate 101 of the testing device 100 and has a flat upper surface. The feeder 110 furthermore comprises two side parts 112, 113, the mutual distance between which can be changed by means of an adjustment device 114. Together with the base part 111, the two side parts 112, 113 form a guide channel 115 for the closure lids, in which guide channel said closure lids are conveyed toward the testing unit 150 owing to gravity. The channel can be adapted to different lid sizes by adjustment of the lateral position of the side parts 112, 113.

[0063] The outfeed 120 comprises a table 121 which is mounted rotatably at an axis 122. The axis 122 is perpendicular to the table plane and also to the plane of the base part 111 of the feeder 110. The table 121 has an eccentric projection to which the end of a piston rod of a pneumatic cylinder 123 is connected via a pivotable bearing. By actuation of the pneumatic cylinder, the table 121 can be pivoted about the axis 122. The outfeed 120 furthermore comprises an opening 125 in the base plate 101 of the device 100, and an inclined outfeed plate 126 which adjoins the opening 125.

[0064] The testing unit 150 comprises a bottom plate 151 on which a stop part 152 is mounted in a linearly displaceable manner. The bottom plate 151 of the testing unit 150 is oriented obliquely, parallel to the upper surface of the base part 111 of the feeder 110. In addition, the two parts are arranged relative to each other in such a manner that closure lids slipping downward on the base part 111 owing to gravity are conveyed onto the bottom plate 151 of the testing unit 150 and take up a predeterminable position there because of the side parts 112, 113 of the feeder 110 and the stop part 152 of the testing unit 150.

[0065] The testing unit 150 furthermore comprises a support plate 155 which is arranged on the base plate 101 of the testing device 100 and forms an oblique support surface, the plane of which runs perpendicularly to the plane defined by the bottom plate 151. A rail 161 of a linear guide 160 is fastened on the support surface of the support plate 155. A spindle 165 with the associated drive, a servomotor 166, is also mounted at its upper end on the support plate 155 and at its lower end on a bearing element connected to the base plate 101 of the testing device 100. The servomotor 166 (or alternatively a stepping motor) is arranged below the base plate 101 and is connected to the spindle 165 via a coupling 167. The longitudinal axis of the spindle 165 runs parallel to the support surface and therefore to the rail 161 of the linear guide 160.

[0066] The spindle 165 interacts with a ball circuit 168 (cf. FIG. 4) which is incorporated in a housing 169. The housing 169 is fixedly connected to guide elements 162, 163 which interact with the rail 161. By actuation of the spindle 165 by means of the servomotor 166, the housing 169 can be moved along the rail 161.

[0067] The testing unit 150 furthermore comprises a positionally fixed, circular-cylindrical mandrel 170 which is connected to the support plate 155 via a force-measuring unit 171. The longitudinal extent of the mandrel 170 runs parallel to the support surface, to the rail 161 and to the spindle 165. The force-measuring unit 171 measures compressive forces transmitted to the end surface of the mandrel 170.

[0068] A take-along sleeve 180 is arranged via a holder 181 on the housing 169 which is movable along the rail 161 with the aid of the linear guide 160. Said take-along sleeve is illustrated in detail in FIG. 5. The take-along sleeve 180 has a cylindrical section with a contact region 180a for a closure lid, in which contact region a bead 180b for gripping behind the guarantee strip is formed. The contact region 180a is adjoined to the rear by a shaft region 180c which merges into a fastening flange 180d. The take-along sleeve 180 is fastened exchangeably to the holder 181 by the fastening flange 180d. Furthermore, the take-along sleeve 180 has two axial grooves 180e, 180f which are arranged running opposite each other on the outer casing, from the fastening flange 180d via the shaft region 180c into the contact region 180a.

[0069] The take-along sleeve 180 surrounds the mandrel 170 coaxially. The take-along sleeve 180 can be moved along the mandrel 170 with the aid of the linear guide 160. This situation is illustrated inter alia in the cross section according to FIG. 4.

[0070] Furthermore, two slitting knives 191, 192, the cutting edges of which extend at a predetermined distance parallel to the casing of the mandrel 170, are arranged on the support plate 155 via a holder 193. The slitting knives 191, 192, like the mandrel 170, are arranged in a stationary manner and all three elements have a fixed location reference. The slitting knives 191, 192 and the take-along sleeve 180 are arranged in such a manner that the cutting edges of the slitting knives 191, 192 are received in the grooves 180e, 180f of the take-along sleeve 180 when the take-along sleeve 180 is moved over the region of the slitting knives 191, 192. The take-along sleeve 180 can therefore be moved from a position completely below the slitting knives 191, 192 into a position completely above the slitting knives 191, 192. If a guarantee strip is taken over by the take-along sleeve 180, by the bead 180b interacting with the inwardly protruding section or the thickening of the guarantee strip, the strip is cut at two diametrically opposite points by the two slitting knives 191, 192 such that two curved sections of 180° each are formed.

[0071] The testing method carried out with the device according to the invention will be explained with reference to the schematic illustrations of FIGS. 6-9. FIG. 6 shows the device 100 in a starting position. The feeder 110 and the bottom plate 151 of the testing unit 150 are provided with closure lids 1.1 . . . 1.4. The latter rest with the base of the lid main body 2.1 . . . 2.4 on the corresponding inclined surfaces, and the opening and the guarantee strip 3.1 . . . 3.4 face upward. The frontmost closure lid 1.1 lies on the stop part 152, and this, together with the side guides (not illustrated here) of the feeder 110 unambiguously determines the position of said closure lid.

[0072] The take-along sleeve 180 with the symbolically illustrated bead 180b is located in a partially retracted position in which it does not have any contact with the frontmost closure lid 1.1. The table 121 of the outfeed 120 is in the pivoted-back state (as is also illustrated in FIG. 3).

[0073] The take-along sleeve 180 is now moved downward with the aid of the linear guide 160 until its contact region 180a with the bead 180b has penetrated the frontmost closure lid 1.1. The bead 180b in this case temporarily presses the inwardly protruding part of the guarantee strip 3.1 radially outward. Owing to its elasticity, said part snaps back inward again immediately after the passage of the bead 180b, such that the bead 180b is positioned behind a corresponding undercut. The situation shown in FIG. 7 arises.

[0074] The take-along sleeve 180 is now moved upward with the aid of the linear guide 160. The frontmost closure lid 1.1 is taken along by the bead 180b of the take-along sleeve 180, the bead being held behind the guarantee strip 3.1. As soon as the frontmost closure lid 1.1 has opened up the path, the following closure lid 1.2 slides down as far as the stop part 152 because of gravity. After a corresponding movement of the take-along sleeve 180, the situation shown in FIG. 8 arises, in which the base 2.1b of the lid main body 2.1 makes flat contact with the end side of the mandrel 170. Before forces are transmitted between the mandrel 170 and the closure lid 1.1, a first force measurement takes place with the aid of the force-measuring unit 171. The corresponding value forms a reference value for subsequent measurements by the difference between subsequently measured values and this reference value indicating the tear-off force resulting because of the interaction between mandrel 170 and closure lid 1.1.

[0075] The table 121 of the outfeed 120 is now pivoted in under the mandrel 170 by means of the corresponding pneumatic cylinder. The pivoting-in movement can be triggered by the take-along sleeve reaching a predetermined height.

[0076] During a further movement of the take-along sleeve 180 upward, an increasing tear-off force arises between the lid main body 2.1, which is supported on the mandrel 170, and the guarantee strip 3.1 held on the bead 180b. During this further movement, the tear-off force is measured by the force-measuring unit 171, and the corresponding force values are transmitted to a processing unit. Upon a certain displacement of the take-along sleeve 180 and a corresponding certain tear-off force, the guarantee strip 3.1 tears off from the lid main body 2.1. It then drops onto the pivoted-in table 121 of the outfeed 120 owing to gravity. Owing to gravity, it slides on the table 121 as far as the lower end thereof and then drops through the opening 125 onto the outfeed plate 126 and from there into a receiving container (cf. FIG. 3).

[0077] The take-along sleeve 180 is moved further up from the situation illustrated in FIG. 9, the take-along sleeve with the guarantee strip 3.1 held on the bead 180b passing the slitting knives 191, 192. The guarantee strip 3.1 is cut into two parts 3.1c, 3.1d by the two slitting knives 191, 192. Since said parts are no longer held back by the bead 180b, they drop downward, owing to gravity, onto the table 121 of the outfeed 120, cf. FIG. 10. They also slide on the table 121 as far as the lower end thereof and then drop through the opening 125 onto the outfeed plate 126 and from there into the receiving container. The movement of the take-along sleeve 180 is now reversed, i.e. the latter now moves downward again. In addition, the table 121 of the outfeed 120 is pivoted back by means of the pneumatic cylinder. The starting position shown in FIG. 6 arises again.

[0078] The speed of the linear movement of the take-along sleeve 180 can be selected differently in the various phases of the described circular process. For example, the following sequence is possible:

TABLE-US-00001 Phase Start position End position Speed 1 - Entry  15 mm  0 mm −v.sub.1 2 - Lifting  0 mm  75 mm v.sub.2 3 - Measuring  75 mm  80 mm v.sub.3 4 - Slitting  80 mm 120 mm v.sub.4 5 - Making available 120 mm  15 mm −v.sub.2

[0079] In this case, as a rule v.sub.3 (measuring speed)<v.sub.1 (entry speed)<v.sub.4 (slitting speed)<v.sub.2 (rapid motion). The measuring speed is as a rule predetermined by a standard and is, for example, 2 mm/s, and the other speeds can be optimized in respect of high process reliability and rapid running Between the measuring and the slitting, it is optionally possible for a further phase to be run at a higher speed than the slitting speed (for example at rapid motion v.sub.2).

[0080] The positions are referenced here from the maximally extended position in which the end surface of the mandrel 170 is only at a small distance of a few mm from the surface of the bottom plate 151.

[0081] For adaptation to different geometries of the closure lid, elements of the described testing device can simply be exchanged, namely the front part of the mandrel, the sleeve, the slitting knives and optionally the stop part. As mentioned, the width of the channel of the feeder can be adjusted. This is also true of the position of the stop part, and therefore the latter generally does not have to be exchanged.

[0082] In order to ensure reliable operation, there are a plurality of sensors present which are not described in more detail here. For example, it is expedient to detect the presence and position of a closure lid on the bottom plate (for example by means of an optical sensor) in order to avoid the testing operation being started if this is not (yet) the case. Similarly, the position of the table of the outfeed is intended to be detected, either by detection of the presence of the table in the space below the mandrel (or the take-along sleeve) and/or by detection of the position of the pneumatic cylinder. This avoids the take-along sleeve, as it is being lowered, colliding with the table which is not (yet) pivoted away.

[0083] FIG. 10 shows a force-displacement diagram of a testing operation. The displacement is plotted along the horizontal axis 10, and the measured tear-off force along the vertical axis 20. It is readily apparent that the tear-off force initially gradually increases after contact of the end side of the mandrel 170 with the base 2b of the lid main body 2. In this phase, in particular the bridges between the main body and the guarantee strip are stretched, which requires a certain application of force. As soon as the guarantee strip tears off, the tear-off force drops abruptly. Relevant variables which can be determined from the profile are the maximally measured force 21 and the corresponding displacement 11. They can be used for assessing the quality of the connection between guarantee strip and main body. If the force profile is considered in more detail, it is also visible when said force profile has, for example, a plurality of local maxima spaced apart in terms of displacement, as a rule in association with a greater displacement value at maximum force. This is an indication of a premature tearing off of a bridge or of some of the bridges. Other characteristics of the profile can indicate a defective clamping of the lid in the testing apparatus, whereupon the result can be rejected and the measurement automatically repeated at the next lid.

[0084] FIG. 12 shows a block diagram of an installation for producing guarantee strips with a testing device according to the invention. The installation comprises a folding/slitting machine 210. In the example illustrated, this comprises a turntable 211 with a plurality of clamping mandrels 212 (6 are indicated here by way of example) for closure lids and a stationary slitting knife 213 which interacts with the clamping mandrels 212 sector by sector and has a cutting edge in the form of a circular arc. The slitting knife 213 is heated by means of a controllable heater 214. The folding/slitting machine 210 also has a controller 215. Corresponding machines are provided, for example, by the applicant PackSys Global Ltd., for example the SPM 35 machine, which, with up to 16 clamping mandrels, reaches a throughput of up to 3,500 plastic caps per minute and both folds and also slits the guarantee strip starting from the injection molding blank (with a selectable sequence).

[0085] The folding/slitting machine 210 and the further components of the installation are controlled and monitored by an installation controller 230.

[0086] According to the invention, a rejection device 220 is now arranged on the output side of the folding/slitting machine 210, by means of which individual closure lids can be conducted to the testing device 100 while the remaining closure lids are conducted on to the next station. Corresponding rejection devices are basically known. An object to be rejected is selected therein, for example, by means of a blast of compressed air.

[0087] A camera 240 for visually detecting the closure lids is arranged between the folding/slitting machine 210 and the rejection device 220. The camera serves for creating images of the individual lids, these images then permit the installation controller 230 to assign the respective closure lid on the basis of impressed or engraved and visually detected identification information to a specific injection mold or cavity.

[0088] As described above, the connection between guarantee strip and lid main body is tested in the testing device 100. The lid main bodies and detached sections of the guarantee strip are conveyed after the measurement into a container 129. The results of the measurements undertaken at a closure lid are then transmitted from the evaluation unit 130 of the testing device 100 via an interface to the installation controller 230. If the results indicate that the tear-off force required for detachment is higher than a predetermined value, the heater 214 is instructed to increase the temperature of the slitting knife 213. If the maximum slitting knife temperature has already been reached or the results indicate a malfunction of the folding/slitting machine 210, an error message is passed to an operator. If the malfunction relates to an individual clamping mandrel 212 or to an individual injection molding cavity, the tested closure lid can be assigned to said clamping mandrel or to said injection molding cavity, which simplifies the repair. If the maximum temperature of the slitting knife is reached, a warning can already be output so that the exchange of the slitting knife can be prepared.

[0089] The invention is not restricted to the exemplary embodiment illustrated. In particular structural details of the individual components can be configured differently. Owing to the speed of the measuring operation and the reproducibility thereof, the testing unit can advantageously also be used in the manual mode. In this case, in particular the feeder can be simplified.

[0090] In summary, it should be emphasized that the invention creates a device for testing a connection of a guarantee strip of a security seal of a closure lid having a lid main body, the device permitting rapid testing.