EP1387812B1 - Device for screwing screw-type closures onto containers - Google Patents

Abstract

A device for screwing a screw cap onto a container with a magnetic coupling arranged between a spindle which can be driven and the closing head, and in the circumferential area of permanent magnets connected to the closing head, an inductive detector for determining the state of motion is provided. As a result, the simplest means are provided to allow the monitoring of the number of revolutions of the closing head, and defects, such as incorrect container clamping, incorrect closing cone and incorrect threadings, can be readily detected.

Description

The invention relates to a device for screwing on Screw caps on containers according to the preamble of Claim 1.

Such a device is described by DE 32 45 966 C2 known. It allows through the magnets and a ring formed from a material of high magnetic permeability Slip or hysteresis clutch a sensitive and reproducible setting of the spindle on the Closing head transferable torque. This works too after tightening a screw cap on the thread the container mouth for safety reasons still a certain Time continues and leads e.g. with faulty threads or insufficient container clamping to a further turn of the Screw head, indicating a faulty closing process is. A monitoring of this process is included the known device is not provided.

Next are already devices for screwing Screw caps on containers known in which the Closing head directly with its own motor adjustable torque can be driven (DE 40 11 398 C2). In this case, the rotational speed of the capping is through monitors its own angle of rotation sensor. This Rotary angle sensor controls for a drive motor for Closing head and generates the other in conjunction with a Evaluation device an error signal when the Locking head rotates at certain points or does not turn. This leads to a rejection of the corresponding faulty sealed container.

Finally, EP 0 467 091 A1 already discloses a Device for screwing on screw caps on containers a torque limiter by a slip clutch or the like. known, at the periphery of the circulating on a circular path Screw heads optically, electrically or magnetically acting Markers are arranged. These marks will be through registered a stationary sensing device, depending on Number of pulses when passing a screw head between a rotating and a non-rotating screw head a distinction is made. The distinction according to the number of pulses requires a variety of markings and a high one Measuring accuracy and thus a high cost.

The invention is based on the object in a device of the aforementioned type with simple means a To allow monitoring of capstan rotation.

This object is achieved by the characterizing in the Claim specified features 1 solved.

In a device according to the invention are anyway existing permanent magnets of the slip or Hysteresis coupling for rotation monitoring of the capping head used. Due to this dual function according to the invention the magnet results in an extremely low constructive Effort. The magnets are generally well protected in a housing arranged so that a microbiological advantageous construction of the closing device not is impaired. The detector has a coil, possibly with a soft iron core, opposite the lock head fixed. In a relative movement between the coil and the Magnet is induced in the coil, a voltage in a connected detection circuit in a simple manner can be recycled. Depending on whether the capping heads perform a self-rotation in addition to the orbital motion or does not result in a different voltage or Waveform.

a) Behälter dreht durch wegen fehlerhafter oder verschlissener Klemmung;

b) Verschließkopf dreht durch wegen verschlissener Verzahnung des Verschließkonus;

c) Schraubverschluss dreht durch wegen fehlerhaftem Gewinde am Verschluss oder Behälter.

The detector may or may not cover the entire orbit of the capping heads. According to a preferred embodiment of the invention, it only monitors those areas in which, in the normal course of the closing operation after tightening the screw cap with the set torque of the magnetic coupling of the capping no longer performs its own rotation. However, if a self-rotation of the magnets is registered in this area, this is, among other things, an indication of one or more of the following faults or faults:

a) container rotates due to faulty or worn clamp;

b) capping head rotates due to worn teeth of the closing cone;

c) Screw cap rotates due to faulty thread on the cap or container.

All these cases leading to a faulty seat of the Can lead through the stationary screw Detected detector. By means of a to this connected evaluation device, it is then depending on Wish possible, e.g. to trigger an alarm, the container with the faulty closure automatically auszuschleusen and / or the locking head, the faulty seat caused to display.

Fig. 1

die schematische Draufsicht auf eine Verschließmaschine für PET-Flaschen, integriert in eine Abfüllanlage

Fig. 2

den senkrechten Schnitt durch eine einzelne Verschließvorrichtung der Verschließmaschine nach Fig. 1 im Bereich des Winkels R

Fig. 3

die Draufsicht auf die Magnetanordnung der Verschließvorrichtung nach Fig. 2

Fig. 4

die Draufsicht auf den Hysteresering der Verschließvorrichtung nach Fig. 2.

In the following, an embodiment of the invention will be described with reference to the drawings. Show it:

Fig. 1

the schematic plan view of a capping machine for PET bottles, integrated in a bottling plant

Fig. 2

the vertical section through a single closing device of the closing machine of FIG. 1 in the region of the angle R.

Fig. 3

the top view of the magnet assembly of the closing device of FIG. 2nd

Fig. 4

the top view of the Hysteresering the closing device of FIG. 2.

The closing machine M of FIG. 1 to 4 is for continuous sealing of PET bottles 3 with conventional Screw caps made of plastic and set in a Filling plant integrated. This also includes a Filling machine 10, one filled with a drink Bottles 3 from the filling machine 10 to the capping machine M transferring transfer star 11 and a filled and sealed bottles 3 of the capping machine M taking over and handed over to a discharge conveyor 13 Outlet star 12. From the filling machine 10, the transfer star 11 and the outlet 12 are in Fig. 1, only the Subgroups shown.

The capping machine M has one about a vertical axis 14 continuously driven in the direction of the arrow rotor 15, at the evenly distributed over the circumference more similar closing devices 1 are arranged. in the The following is the structure of one of these Closing devices 1 with reference to FIGS. 2 to 4 closer explained.

The device 1 has a rotatably mounted in the rotor 15 Spindle 4 with vertical axis of rotation. The spindle 4 sets They are composed of several parts, the same one on the right are hatched in ascending order. In the lower, hollow end of the Spindle 4 is a closing head by means of two rolling bearings 16 5 freely rotatable with a likewise vertical axis of rotation stored. Also, the closing head 5 is made up of several Share together, the hatched uniformly rising left are. In the lower area, the closing head 5 in conventionally a resilient hold-down 17, a toothed sealing cone 18 and an elastic Retaining ring 19 for the screw caps, not shown.

On the outside of the capping head 5 are eight Permanent magnet 7 fixed with alternating polarity, such as in Fig. 3 is shown. The cylindrical on the outside Arrangement of the permanent magnet 7 is with a small air gap concentric of a hysteresis ring 2 made of material with high Permeability, e.g. Soft iron, surrounded at the Inside the spindle 4 at the level of the permanent magnet. 7 is attached. The permanent magnets 7 and the hysteresis ring 2 together form a magnetic coupling 6, more precisely a Hysteresis clutch, which in a wide speed range predetermined torque from the driven spindle 4 the relative to this rotatably mounted locking head. 5 transfers. The size of the torque is through Height adjustment of the hysteresis ring 2 adjustable; in Fig. 2 is on the left side the setting with maximum Torque and on the right side with the setting shown minimum torque. The permanent magnets 7 stay at the same height.

As shown in FIG. 2, is at the bottom of the rotor 15 for each closing device 1 by means of vertical bars 20th a horizontal support plate 21 for a to be closed Bottle 3 attached, which has a radially outwardly open U-shaped Has recess 22 for the bottleneck. At the Top of the holding plate 21 is one with several upwards directional tips provided pad 23 attached. On the Pad 23 and their tips is the occlusive Bottle 3 with its support ring on and is so in Cooperation with the spring-loaded down 17 applied contact force secured against rotation. Through a stationary guide arc 24, the bottle 3 in the Recess 22 held. The guide bow 24 sweeps the entire transport area of the bottles 3 in the area of Closing machine M and is equipped with several stationary columns 25 on not shown, non-rotating upper part of the rotor 15th attached. A bottom support for the bottles 3 is not intended.

During operation of the capping machine M with rotating rotor 15 are the spindles 4 by a not shown Planetary gear in self-rotation offset and that in the V and R marked angular range of their orbit. there is the designated V closure angle for a proper closure of the bottle 3 is required, wherein the spindles 4 and the hysteresis over the sixth entrained capping head 5 at usual Turn screw caps to a maximum of approx. 2.7 turns. Then the screw cap is set with the Torque firmly screwed onto the bottle 3 and this is properly sealed. Within the marked with R Residual angle of the orbit, the spindles 4 continue in Rotation offset; the Verschließköpfe 5, however, are here normally silent, with the slip through the Hysteresis 6 is added.

In the region of the residual angle R is a stationary detector. 8 arranged to monitor the speed of the Verschließköpfe 5. Of the Detector 8 is rigid on the guide arc 24 or its Support pillars 25 attached and indeed at the level of Permanent magnet 7. He lies with his to the axis 14th pointing sensor surface with a small distance in the orbit spindles 4. In the area of the sensor surface is in the housing of the detector 8 an elongated coil 9 with good electrical Conducted liquid-tight, which with a Detection circuit 26 is connected. The coil 9 is aligned horizontally and covers in the embodiment exactly the residual angle R from.

Runs a capping head 5 without self-rotation at the detector. 8 over, so in the coil 9 depending on the angular position of the Permanent magnet 7 a more or less large, however constant voltage induced. Leads the other hand Locking head 5 when passing the detector 8 a Self-rotation, so by the at the coil. 9 vorbeidrehenden permanent magnet 7 a pulsating or AC voltage induced. This different voltage or waveform can by the detection device 26th be distinguished without doubt. This generates a Error signal if it has a pulsating or alternating voltage tracking. This error signal is sent to the detector 8 connected evaluation device 27 forwarded.

The evaluation device 27 solves in the simplest case Alarm signal, causing the operator on the is made aware by spinning closure head 5, the Signs for one of the in the description introduction described disorders a) to c) is. It is also possible that the evaluation device 27 upon receipt of a Error signal the sorting out of the spin Closing head 5 processed bottle 3 triggers. This can e.g. with the help of not shown controllable brackets in Outlet star 12 done, which the faulty bottles to sort out on a separate conveyor track 28. It is next expedient, the evaluation device 27 with a not Paired bottle sensor shown in the absence of a bottle 3 under a then spinning Sealing head 5 suppresses an erroneous error signal. Furthermore, it is possible that the evaluation device 27 the revolving through the capping head and indicating what For example, the exact angular position of the rotor 15th monitoring angle encoder is connected. This is also advantageous to the evaluation device 27 or the Detection circuit 26, the respective speed of the Rotor 5 or the spindles 4 to communicate.

In the present case is between the permanent magnet 7 am Closing head 5 and the detector 8 nor the hysteresis second the magnetic coupling 6 is arranged. The evaluation by the Coil 9 is thereby not disturbed, since the hysteresis 7 Although has a high permeability, but not even Magnetic field. The through the permanent magnet. 7 generated magnetic fields beat through the so to speak Hysteresis ring 2 through to the coil 9.

In contrast to the described embodiment, the Detector 8 also has a larger circumferential angle of Verschließköpfe cover 5 and it can also be several coils. 9 exhibit. Also it is possible in certain places too monitor whether a capping head 5 rotates and on Generate error signal if it does not self-rotation performs, e.g. in the closing angle V.

Claims (3)

1. Device (1) for screwing a screw closure onto a container (3), with a spindle (4) which can be driven and with a closing head (5) which can be rotated relative to the latter, a magnetic coupling (6) being arranged between the spindle and the closing head, the magnetic coupling (6) having a plurality of permanent magnets (7) that are connected with the closing head so as to be fast against rotation, and the closing head circulating along a circular track, characterised in that an inductive detector (8) is arranged fixed in position in the circular track of the closing head (5) in the circulation region of the permanent magnets (7), the inductive detector (8) capturing the state of movement of the permanent magnets (7), and in that the detector (8) has at least one electric coil (9) in which a voltage can be induced by the permanent magnets (7) as they rotate past, and in that the coil (9) is connected to a detector circuit (26) which can distinguish between a steady voltage when there is no rotation present of the closure head itself and a pulsating or AC voltage when there is rotation of the closure head itself.
2. Device according to claim 1, characterised in that the detector (8) is arranged in a residual angle (R) which follows the closing angle (V) of the circular track of the closing head (5), no rotation of the closing head (5) itself normally taking place in the residual angle (R) during a regular closing process.
3. Device according to claim 1 or 2, characterised in that an evaluation device (27) is connected to the detector (8), which, when the detector (8) registers a faulty state of movement of the permanent magnets (7), triggers an alarm and/or the removal of the container being processed by the closing head (5) that continues to turn and/or the identification of the closing head (5) that continues to turn.

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