WO1993004960A2

WO1993004960A2 - Process and device for transporting items in a continuous transport flow, process and device for determining the position of a mark by means of said transporting process

Info

Publication number: WO1993004960A2
Application number: PCT/CH1992/000167
Authority: WO
Inventors: Martin Lehmann
Original assignee: Martin Lehmann
Priority date: 1991-08-29
Filing date: 1992-08-21
Publication date: 1993-03-18
Also published as: JPH06501907A; EP0558705A1; AU2406592A; DE4128733C2; WO1993004960A3; DE4128733A1

Abstract

In order to allow certain operations to be carried out more at standstill and thus more easily at a work station (9, 84, 27) that works on continuously moving items, for example plastic bottles (1), the individual items (1) are transported by a feed screw (5), the pitch of which increases in the transport direction, in the direction of the work station (9, 84, 27), are intermittently transported within the work station (9, 84, 27) then are brought back to the continuous transport flow by another feed screw (5a), the pitch of which decreases in the transport direction.

Description

_ τ_ _

Transport method for piece goods occurring in a stream, transport device therefor, method for determining the position of a marking by means of such a transport method and system therefor

The present invention relates to a transport method for piece goods occurring in a stream to and from at least one work station for at least one piece goods, the piece goods being continuously conveyed before and after the work station, further relates to a transport device for carrying out the method and a A method for determining the position and / or for reading and / or applying a marking from or to goods (s) accumulating or accumulating in a stream and a system therefor further relates to a method for applying a code marking Plastic bottles in which a laser beam is divided into a laser beam by a beam splitter and a relative movement is created between the laser beam and the plastic bottle.

There are a large number of work processes which are to be carried out on piece goods, which occur in a continuous stream, piece goods behind piece goods, and are to be conveyed further. Up to now, the piece goods processing to be carried out at a work station has either been carried out in such a way that the work was carried out during the created relative movement between the work station and piece goods or by moving the work station with the continuously conveyed piece goods. On An example of the last-mentioned technique is known from EP-A 0 295 371, according to which plastic bottles are conveyed as piece goods, inter alia by means of star wheels, and, for carrying out work on the plastic bottles, working stations on the star wheel with sensors and corresponding evaluation electronics ¬ tronics are attached so that the desired work is carried out by means of workstations, which, as a reference system, rest on the star wheel. The continuous flow of the piece goods to be processed is maintained.

This procedure is disadvantageous insofar as sensors, generally the workstations mentioned, are moved with respect to an absolutely stationary reference system, namely are moved with cen piece goods and therefore complex and fault-prone connections to the workstations have to be created, such as by means of sliding contacts, such as this is performed in the above-mentioned EP-a 0,295,371, and in that the air for Be¬ industrial operating in rough actually schaf¬ fenden arrangements for _ensuring a zuver¬ transmitting data acquisition selected very difficult on the ge, moving with the piece goods "Vehicle" can be built.

In one of its aspects, the present invention is based on a method of the abovementioned type and aims to remedy the disadvantages mentioned.

For this purpose, a transport method according to the invention of the above-mentioned type is distinguished by the wording of the characterizing part of claim 1. The above-mentioned problem is solved in a very simple manner in that the conveying takes place at least by the work station in conveying steps, discontinuously. The continuous conveying movement on at least one conveying section, in a further conveying section along or through the work station, is therefore converted into a discontinuous step conveying, whereby it is ensured that the continuity conditions with regard to the general cargo flow are maintained.

It is now possible to equip the workstation absolutely at rest and with all the necessary precautions to ensure data security. There are no vibration problems as they occur with moving workstations, and no connections and taps are required which would have to take up a relative movement. In stoppage ^phases' of the step support can, under quasi "Laborbedingun¬ gen", a highly accurate work can be taken vorge on cargo, even though this piece goods, continuously conveyed stream is part of the er¬ mentioned.

A transport device for carrying out the method mentioned is distinguished according to the wording of claim 2.

A very simple possibility on the transport device mentioned to implement the continuously operated first conveying device and, as will be explained below, synchronization for the transfer or takeover of the piece goods to or from the second intermittently operated conveying device. To create a direction arises in the case of a procedure according to the wording of claim 3, namely in that the first conveyor device comprises a conveyor screw arrangement.

Often the piece goods mentioned occur in a practically uninterrupted sequence, on their continuous conveying path, which is unfavorable for the work to be carried out subsequently, since this requires a certain time and a certain space, which would require a predetermined spacing of the piece goods .

Using the above-mentioned screw conveyor arrangement, this problem can now be easily solved in that, according to the wording of claim 4, the piece goods are deliberately accelerated or decelerated along the screw conveyor by varying the screw auger pitch, which means that there is no problem in front of the work station and thereby increasing the Screw pitch, there is a continuous increase in the distance of the piece goods, after the work station, if necessary, again a continuous unlocking of the piece goods with a decreasing conveyor pull pitch of the screw.

Following the wording of claim 5, a takeover or transfer starwheel is also preferably provided for the transfer or transfer of the piece goods from or to the first continuously conveying conveyor. The latter takes over or transfers the piece goods, but is driven for this intermittently, ie in steps, and takes of a respective receptacle brought into the correct position, or delivers a respective piece goods from the first conveyor device.

Although in the case of some piece goods to which the transport method mentioned is applied with the aid of the transport device mentioned, mechanical impact stress can certainly be accepted, it is essential in the case of other piece goods to be treated in this way Lich, as for example in the case of plastic bottles, glass containers, etc., that the change from continuous to discontinuous conveying or vice versa takes place essentially without mechanical impact stress. This is ensured on the transport device of the type mentioned, which is designed according to the wording of claim 6.

A batch of the second conveyor, that is to say the intermittently moving one, which comes into contact with a particular piece of goods, referred to as the takeover, is moved in the same way as a batch of the first conveyor, ie the continuously conveying, which latter batch is the continuous one Feed occurs immediately before and during the takeover phase for the general cargo. For a short period of time and viewed from the piece goods, the two conveying devices move in the same way as far as their areas of application are concerned, and the second conveying device then removes the piece goods from the first, by a steady acceleration away from the Conveyor path of the first conveyor, ie the continuous conveyor. Following the wording of claim 7, the transport device according to the invention or the transport method mentioned is particularly suitable for conveying plastic bottles as general cargo, on which test work, such as volume testing, density testing, is to be carried out at the work stations. In particular, however, work stations are addressed which contain markings with information such as about the contents of the bottle, the manufacturer of the bottles or the number of use cycles which such a bottle has lived and which are found, read, interpreted and found on the bottle if necessary, as with the usage cycle count, must be changed.

The above-mentioned problems, which arise when work stations with a continuously conveyed flow of piece goods have to be moved in order to carry out the work, arise to an increased extent if, as mentioned, such markings, a code, to work on such piece goods. A falsification of information or a loss of information should be ruled out as much as possible in the case of such work, which requires a very substantial outlay in the case of moving work stations.

In order to solve this problem when determining the position and / or for reading and / or applying a marking to piece goods occurring in electricity, the wording of claim 8 is used in such a way that, very specifically for this delicate pro ¬ problem that the transport procedure discussed above is set and in particular the position determination and / or the application of the marking and / or its reading is carried out during at least one standstill phase of the conveying steps. In the case of such a method in particular, the realization of almost "laboratory conditions" during the work phases is of crucial importance and considerably reduces the effort to be taken to ensure data security.

If one takes into account that it is precisely for position determination and / or for reading and / or for attaching the markings mentioned on the piece goods, which marking is located on the surface of the piece goods somewhere and to a predetermined extent or is to be applied it can be seen that the construction effort is fundamentally reduced by the fact that the equipment for performing the work mentioned acts on a limited effective window and a relative movement is created between the equipment and the piece goods, as mentioned to find the marking position for the Le ¬ the marking or to apply, including a change, the mentioned marking.

This requirement would now be met by a procedure according to claim 8 with the above-mentioned method. According to the wording of claim 9, this is now solved, however, by creating a relative movement between general cargo and the arrangement for carrying out the work mentioned in the standstill phase of the step promotion. It is clearly preferred that the arrangement for carrying out the mentioned To leave work absolutely stationary and to create the relative movement mentioned by moving the respective piece goods.

In the vast majority of cases, for example and in particular in the case of containers, bottles, plastic bottles, etc., it is determined in advance on which wall areas the mentioned marking is to be provided, be it on the floor, in the opening area and / or on a specific wall area, such as the bottle coat. Taking this into account, there is now a very simple possibility of creating the relative movement mentioned, by proceeding according to the wording of claim 10, namely by moving the piece goods ^' around an axis, in the aforementioned standstill phase.

In view of the fact that on the one hand the highest possible throughputs of processed piece goods can be achieved and that the effort for carrying out the work mentioned is further minimized, it can be seen that in a preferred embodiment variant according to the wording of claim 11 above to be dealt with, which consists in particular in determining the position of a certain marking and applying a marking in the same standstill phase of the step conveyance and preferably, with rotation of the piece goods, within at most two revolutions. It is often necessary to change an already existing marking on a piece goods. This, for example, and in particular in the case of the plastic bottles mentioned, in which, in the context of reuse, after completion of a cycle of use, via the consumer, back to the new filling, how often such a cycle has been completed. It is a number of cycles marking, for example by one, for each newly started or ended cycle. If one wants to avoid the effort of applying such an incremental marking to bring the piece, such as the plastic bottles, with respect to the application station into a predetermined absolute position, the position of an already existing marking is first recorded as one Reference point on the piece goods, such as the plastic bottle, with respect to which the marking change can then be made.

Therefore, according to the wording of claim 11, the position determination and the marking applied are carried out in the simplest manner in the same standstill phase of the step promotion, which also ensures that without extensive data backup and conversions directly after the position determination the position for applying the marking can also be determined.

With the preferred rotation of the piece goods mentioned, in particular for reasons of time optimization, the position is determined and the marking is applied within a maximum of two piece goods revolutions. This is two, because it is often not ensured that the marking position can be detected with the relative rotation mentioned before - within one revolution - a location determined in this regard for the application of the marking on the corresponding Aufbriπggerät has passed. If it is ensured that the position determination is always completed before the piece goods or bottle area on which a marking is to be applied has passed the corresponding device, then it is entirely possible to determine the position and the application within a single rotation deal.

Following the wording of claim 12, in the procedure described here, for reasons to be explained, marking with a highly desired effect is carried out by means of a laser.

A laser marking method has been known for a long time from EP-A 0 079 473, in which a laser beam is divided into a beam of parallel beams by means of a beam splitter, such as a splitter matrix, the latter for applying marking to a piece good such as on glass containers or plastic containers. This beam distribution results in an incident radiation diffusely reflecting surface on the surface of the corresponding piece goods; the incident individual rays burn a pattern of small recesses. According to this document, it was recognized and subsequently also confirmed that a substantially increased uniformity of the baked-in pattern mentioned is achieved when, in the marking application phase, a relative movement is given between the bundle of individual jets and the piece goods being treated becomes. According to the document mentioned, this is achieved in that the beam splitter is moved during the marking. If a movement of the piece goods is created, for example when conveying piece goods occurring in a stream, the result is the extremely simple possibility of moving the beam splitter instead of, as is known, the movements already provided for other reasons, in particular for the purpose of conveying ¬ use of the piece goods also for generating a relative movement between the beam and piece goods.

According to the wording of claim 13, this is used consistently in the above-mentioned method and, according to the wording of claim 22, results in a considerably simplified method per se for applying code marking to moving plastic bottles; a separate drive device for the beam splitter does not have to be provided.

In a highly simple manner, in accordance with claim 14, the piece goods are set into the aforementioned rotational movement in that the piece goods are in frictional engagement with an already rotating rotation plate before the standstill phase of the step-by-step conveying, in particular in the acceleration phase is brought into engagement and the relative rotational movement of the rotation plate and the applied piece goods is reduced when the frictional engagement is created, so as to reduce the frictional load on the piece goods and the plate.

A system for performing the above-mentioned process For the determination of position and / or reading and / or for applying a marking - be it a new application or a modification of an existing marking - on piece goods occurring in a stream is distinguished by the wording of claim 15.

Preferred embodiment variants of this system are distinguished according to claims 17 to 21.

The invention is subsequently explained, for example, using figures.

Show it:

1 is a plan view of a simplified system according to the invention, which carries out a method according to the invention for determining the position and / or for applying a marking and / or for reading it, in which system the transport method according to the invention and, accordingly, is carried out which are realized according to the transport device according to the invention,

2 to explain the takeover or transfer criteria for general cargo from continuous conveyance to step conveyance or vice versa, representations of the displacement path of respective conveyor device points as a function of time during a transfer phase,

Fig. 3 is a simplified, partially sectioned Side view of part of the system according to FIG. 1, namely the step conveyor with a position detection device and marking application device,

4 in the form of a simplified function block diagram, a controller used in the system according to FIG. 1, with which, based on a position detection of a marking already present on a piece goods, the position for the new application of a marking on the piece goods is determined and, by means of a laser source at the correct position, a change of marking or a new marking is carried out.

1 schematically shows a top view of an arrangement according to the invention which operates according to the method according to the invention and by means of which testing and treatment processes are carried out on plastic bottles as piece goods to be treated. At the same time, the system presented initially comprises or works according to a conveying method according to the invention, according to which a piece of general cargo, namely the plastic bottles, which is generated in a stream, is provided for carrying out more precise work along a conveying section, which is considered as being continuous is along which the piece goods are conveyed intermittently, ie in steps. The work or test procedures which require the aforementioned precision are therefore carried out in the standstill phases of the intermittent funding along the mentioned funding section. taken.

Plastic bottles 1, standing on a schematically indicated conveying plane 3, are continuously conveyed forward in the direction indicated by the arrow p by means of a feed screw 5. The screw 5 with the conveyor thread 7, in which the bottles are pushed forward, has an increasing pitch of the thread 7 downstream of the conveyor section 9 with intermittent conveyance, as a result of which the bottles 1 are continuously accelerated towards the conveyor section 9 mentioned. At the downstream end of the screw 5, the thread 7 continuously merges into a cylindrical journal 11. The screw conveyor 5 is driven by a motor 13 at a constant rotational speed via transmitters such as toothed belts.

The conveying section 9 for intermittent conveyance primarily comprises an input-side star wheel 15 and an output-side 17 which is followed by a further conveyor screw 5a, constructed in the same way as the screw 5. A threaded pull 7a continuously emanates from an axle pin 11a, the slope of which decreases in the direction of conveyance, whereby the bottles 1, which are in turn continuously advanced, are retarded and their distances are reduced. Due to the above-mentioned increase or decrease in the conveying thread 7 or 7a, the bottles 1 which are essentially flush, for example conveyed by a conveyor belt, are spaced apart in front of the conveying section 9 or are spaced apart on the output side of the conveying section 9 Relation moved together again, for example before forwarding to another conveyor belt, not shown here.

The star wheel 15 on the input side is driven by the motor 13 itself, like the worms 5, 5a, via a belt connection 18 and a step mechanism 21 with predetermined step characteristics, synchronously with the worms 5 and 5a, while others still to be described Star wheels and in particular also the star wheel 17 on the output side are driven by the input 15 via a further toothed belt 23.

A bottle la which has reached the downstream end of the screw conveyor 5 is essentially free of bumps, i.e. transferred to the star wheel 15 and conveyed away from the linear conveyor path of the screw 5 by the latter.

In FIG. 1 the bottle 1 a is moved into one of the conveyor recesses 25 provided regularly on the star wheel 15 and is, however, initially fed linearly by the screw 5, while the star wheel 15 only shortly afterwards, in a manner to be described below, from the standstill phase shown with a conveying step the bottle la, at the transition from the thread 7 in the pin 11, will take over.

With reference to FIG. 2, without claiming to be exact, a simplified model is used to show more heurally how the conveying speed by means of the worm 5 in the transfer area and the step control of the star wheel 15 are to be designed in order to make the shock-free as possible Transition from continuous Chen, linear conveyor path - along the screw 5 - in the conveyor section 9 or in its star-side 15 on the input side with intermittent step operation.

A recess 25 of the star wheel 15 is shown schematically at the top left in FIG. 2, with a considered point A of its leading flank and a considered point B of its trailing flank. The linear conveying direction of the screw 5 is represented by X, based on the axis center 0 of the star wheel 15. Between & and the expansion of a bottle considered in the X direction is shown schematically.

In the diagram further shown in FIG. 2, the path coordinate x is plotted over time t as it was just defined.

As is known, the projection of a circular movement results on a right-angled coordinate system placed through the center of the circle for each phase-shifted sinus curve, and correspondingly a circular path results from the composition of such orthogonal sinus curves according to the Lissajou system.

With the curve A ¹ Bewegungspro is ection to the X-axis of the point A is represented, with the phasenver¬ pushed curve B * that of the trailing point B. The phase shift corresponding to T corresponds to the opening angle * 9 schematically illustrated ^• Einnehmung 25, under Taking into account the rotational speed CJ of the wheel 15. During the last movement phase of a bottle 1a to be taken over on the screw 5, as shown in FIG. 1, the star wheel 15 stands still. At the moment which is arbitrarily set as the zero point in time, the star wheel 15 is immediately set into a constant rotational movement in accordance with the simplified view. Taking into account the standstill mentioned, the curve profiles x and x shown in solid lines for the two

AB sought points A and B. If the bottle 1 with the extension rt, ß enters the area of the star wheel 15 or the receiving recess 25, its leading point O may be the X coordinate of point A on the leading recess flank do not reach, since otherwise there is a collision between the bottle and the leading intake flank. The leading point & of the bottle 1 must therefore be in the

Load diagram in an area below curve x

A because of and may at most reach x. This self-

A is understandable only until the bottle is taken over by the star wheel 15.

The area mentioned below the curve x is

A hatched. The takeover of the bottle, viewed in simplified terms, takes place by contacting the lagging point β of the bottle 1 by the

Point B of the trailing intake flank 25. The Y coordinate of point B, which is not further considered here, must be in the idle phase of the star wheel

15 and while the bottle la is entering the

Recess 25 obviously be dimensioned so that the bottle la contactlessly lagging

Star wheel flank, corresponding to B, can happen. Now, while the bottle la continues to be conveyed by the screw 5, but is already in the position shown in FIG. 1, the trailing flank, corresponding to point B, of the recess 25 should catch up with the trailing point P of the bottle and its propulsion as far as possible take over bumpless. Impact resistance is ensured if, for simplicity's sake only in the X direction, the trailing intake flank point B touches the bottle 1 at P when the speed of the point B in the X direction is still the same as that the conveyor screw 5 is the conveying speed of the bottle 1a. In the diagram shown, this means that the conveying line xß of point r should tangentially touch the movement curve x of the trailing intake flank. At the moment of contact T, the p conveying action of the screw 5 must stop, ie the screw conveyor 7 must continuously pass into the pin 11.

In the diagram, the steepness of the conveying straight line xß represents the conveying speed of the bottle la on the

Auger 5 in the transfer area. This straight line must not be below the

Curve x lie, because this would mean that point ι * the

B bottle 1 the trailing flank according to point

B catches up and not the other way around, as requested. At the moment t, the bottle point ß passes through the x coordinate value of the point B which has just stopped.

It is therefore determined that the straight line of motion xß the movement curve x after its zero crossing and

B the change of sign of their second derivative must take place there. This case is shown in FIG. where the line of motion xp tangent to the

Point of contact P with curve x runs, at which

Point P bump-free contact between point B on the trailing capture flank with the trailing one

Limiting point fi of bottle 1 takes place. Then the bottle point ß follows the movement curve of the

Point B, namely according to curve x.

B

As shown, the bottle point β has passed the X coordinate of point B immediately after the star wheel 15 has stopped. With the straight line x _w , parallel to the straight line x ^ with X -distance d, the movement path of the leading point Ci of the bottle 1 is shown, which, as can be seen, never reaches the X coordinate of the leading flank A of the recess 25 the latter is not involved in the takeover process at all. The point oi naturally follows after the takeover time t

P the course of the curve x.

B

Adherence to the shock-free bottle takeover is determined by the conveying speed of the screw in the transfer area, the phase of rotation of the receiving receptacle 25 in its standstill phase immediately before the takeover, and, as an important influencing variable, by the choice of the acceleration behavior of the star wheel

upon initiation of the takeover step.

Through such first approximate considerations, if necessary refined by taking into account the shape of the recess 25 ^ of pfXbroll processes in this recess in connection with considerations also in Y- Direction, an at least substantially impulse-free transfer of the bottle la to the star wheel 15 can be realized.

In this way, bottles 1, generally of conveyed piece goods, are continuously transferred from a continuous conveying path into the conveying section with step conveyance. The analog considerations show the conditions at the transition from star wheel 17 to an output screw 5a.

Up to now, the conveyor technology according to the invention has been explained with reference to FIGS. 1 and 2.

Now, specifically designed for the intended purpose, further inventive measures are shown in FIG. 1 and in the figures still to be discussed.

The purpose of the present system is to read and change a code marking provided on the cylinder wall of piece goods, in particular the bottles, in particular plastic bottles 1. A coding, which has to be read and changed, is present when the bottles 1 are bottles to be reused, which go through several use cycles, ie are filled, are introduced into the consumer circle, and are returned for filling after emptying. The purpose of the addressed code is to record the number of use cycles that have already been used and the code in accordance with the current newly completed or just started use cycle in the Change the meaning of an increment. The code addressed here can of course form part of an overall code, which overall code can also contain information about the filling substance, manufacturer, date of manufacture etc.

Such codes are applied in particular to plastic bottles using a laser. As mentioned at the beginning, EP-A-079 473, the content of which is explained as an integral part of the present description, describes a method in which a laser beam is divided into a plurality of beams by means of a matrix and by means of the divided one A surface field of the processed piece goods is scanned in order to form a surface structure similar to a reflector. Tests have also shown that a relative movement between the beam and the surface to be treated brings about a homogenization of the surface treatment, this relative movement being achieved in said patent by the movement of the beam-splitting grating in the laser beam, whereby there is obviously a shift of the individual jets with respect to the surface of the piece goods.

It has now been shown that if piece goods, such as the plastic bottles mentioned, are moved translationally past a sensor head for detection and subsequent decoding of the code or moved translationally and / or while a marking is being applied with such a laser arrangement, the required reading or decoding security or The required precision of application is or are much more difficult to achieve than if the piece goods, such as the plastic bottle mentioned, are translationally stationary during these operations, but a rotation of the piece goods, such as the bottles, about its axis both during reading for decoding, and also and in particular also for the precisely positioned laser code application is advantageous. This is particularly because the speed of the rotation mentioned can be selected independently of the conveying speed of the piece goods.

In FIG. 1, a star wheel 27 developed to a treatment carousel is now provided within the conveyor section 9 with step conveyance, which is driven synchronously with the star wheels 15 and 17 via the belt drive 23 mentioned and to which the star wheel 15 via further star wheels 29. 31 the bottles 1 are promoted.

The carousel star wheel 27 is shown in section in FIG. 3.

The carousel star wheel 27 comprises an axle shaft 33 which carries upper and lower star wheel parts 35, 35 o u. These star wheel parts 35 and 35 encompass the plastic bottles 1 shown above at their cylindrical central region and have the correspondingly dimensioned recesses 25 according to FIG. 1.

As already shown in FIG. 1 on the star wheel 15 with disk 39, these are shaped as shown here. bottles on the star wheels are preferably not only accommodated in star wheel recesses on their cylinder area, but are also held on their neck area with correspondingly shaped recesses. The plastic bottles processed here have a protruding collar 37 on their neck. When the star wheels 29 and 31 are transferred to the carousel star wheel 27, the bottle collars 37 are placed in a holding fork 40 with a recess 39, in which the bottles 1 hang. The holding forks 40 are connected in the same way as the star wheel parts 35 and 35 in a rotationally fixed manner to the above-driven axis 33, but a fork carriage 41 is displaceable along the axis 33.

Above the fork carriage 41, a freely rotatable muzzle pin 44 is rotatably mounted on a likewise axially displaceable carriage 43. Fork carriages 41 - indirectly - and carriages 43 with muzzle pins 44 - directly - are driven axially by a pneumatic drive 46 which is connected in a rotationally fixed manner to the axis 33 on an axially fixed bearing plate 48. The positions of the bottle, fork carriage 41 and slide 43 with muzzle pin 44 are shown on the right in FIG. 3 when the bottle was taken over directly by the star 29 or 31 through the carousel star 27 or shortly before the bottle 1 from the carousel star wheel 27 the star wheel 17 on the output side of the conveyor section 9 is transferred. The corresponding positions during bottle treatment on the carousel star wheel 27 are shown on the left in FIG. 3. From this it can be seen that by means of the pneumatic drive 46 the carriage 43 is driven downwards until the freely rotatable mouth pin 44 rests in the mouth of the bottle 1 and over this the bottle 1 is pushed further down, which results in a corresponding displacement of the fork carriage 41 against the force of an upward acting tension spring 50 takes place. When the drive 46 is relieved of load, the slide 43 is lifted up, the pin 44 is removed from the mouth of the bottle 1, and the spring 50 drives the fork slide 41 with the bottle up again; this up to the stop 52.

The axis 33 is driven in steps by the belt 23 shown in FIG. 1.

At the bottom rides, rotatably, on the axis 33 a sun gear 54 which is continuously driven by the motor shown at 56 in FIG. 1 and a belt 58. A planet wheel carrier 60 is provided in a rotationally fixed manner with respect to the axis 33, with planetary gear plates 62, their axes A with the central axes of the recesses

62 25 or the forks 39 are aligned, so that when the bottles 1 are picked up, the latter hover centrally over the plates 62, as shown on the right in FIG. 3.

The planet wheel plates 62 are driven by planet gear wheels 64, which are in engagement with the sun gear wheel 54.

If a picked-up bottle 1, according to the position on the right in FIG. 3, is brought into the working position, namely by transition into the position shown on the left, then, as has been explained, it is lowered and comes into frictional engagement with the associated planet wheel plate 62, whereby it is rotated, resiliently supported on the muzzle pin 44, in rotation. The rotational movement of the planet wheel plates 62 is uniform and is independent of the intermittent, stepwise rotation of the plates about the axis of the shaft 33 with the star wheel arrangement. In order to reduce the frictional load on the bottle base when contact is made with the planetary wheel plate 62, the lowering movement of the bottle is carried out during a respective acceleration phase of the stepped axis 33, and the rotating movement of the sun wheel 54 and the rotating movement of the shaft 33 are rectified. If the rotational movement of the shaft 33 is aligned with the rotational movement of the sun gear 54, the rotational movement of the planet wheel disc 62 is reduced in this acceleration phase of the axis 33, which minimizes the abovementioned frictional load on the bottom of the bottle. If, in extreme cases, a planet gear rotates at the same rotational speed as the sun gear around shaft 33, the former no longer rolls on the sun gear, its own rotation becomes zero.

With the system shown, about 5 bottles per second are delivered or removed. Thus, the crotch conveyor arrangement 9 must also continue to convey five bottles per second, which, with a duty cycle of 1, results in downtimes of approximately 0.1 seconds for the step rotation movement.

On the carousel shown in FIG. 3, at least the position of a pre-applied code marking on the bottle periphery is now to be detected. and then the code marking can be changed at a further predetermined position in this regard by shooting a further marking. This is shown schematically with reference to FIG. 4.

On the bottle 1, every time it returns from a consumer cycle of use, a bit-like marking field, as shown schematically at 66, is shot with a laser according to the aforementioned EP-A 0 079 473. The bottle 1 shown in FIG. 4 and placed on the schematically drawn planetary wheel plate 62 has a marking field 66 and has thus already been filled once and put into circulation. It is now available a second time for further filling. In a standstill phase of the carousel star wheel 27, during which the bottle 1 is rotated via the planet wheel plate 62, be it by transmission measurement or reflection measurement, it is detected with a detector unit 68 when the marking 66 indicates a predetermined rotational angle position a goes through. The moment at which the applied marking 66 passes through the predetermined position, for example given by the position of the detector unit 68 or its window, is detected, and a laser source 72 is triggered via a time delay circuit 70, the beam 74 of which is triggered by a division measure - trix 76, as if divided by a grid, into a single beam bundle. This is set up directly or via a mirror arrangement 78 on the rotating bottle 1. At the time delay circuit 70, in accordance with the given rotational speed of the bottle 1 and the required relative position of the change marking with respect to the The marking 66 calculates the time difference which elapses from the detection of the field 66 until the position of the intended change marking 66 lies in a laser effective position.

Since the position of the mark 66 on the circumference of the bottle is not known, the bottle must make a full revolution to detect it. Now, when the predetermined position has passed 66 for labeling change a at detecting the position of 66 already on the laser effect region needs to La¬ serauslösung maximum of a further rotation of the Fla¬ be specific carried out, otherwise the laser in the first round can be triggered ^' become. Accordingly, at least one, preferably not more than two, bottle rotations are preferably required for the position detection of the reference mark 66 and the application of the change mark.

Instead of a laser triggering due to the time conditions, it is also entirely possible to provide a position control for the laser, for example by angularly controlling a gimbal-mounted deflection mirror 78 via a position control unit 80, around the laser beam on the rotating bottle exact to apply. However, both techniques, ie taking into account the time delay .DELTA.i and position control, can be used in combination, in particular even if the marking configuration is not provided as a line, as shown in FIG. 4, on one circumferential end, but for example as a marking field, two-dimensional. Such two-dimensional coding systems are For example, known as data code matrices, such as developed and published by International Data Matrix Inc. 28050 US 19 North, Suite 100, Clearwater, Florida, USA.

The carousel star 27 stands still during the entire machining process, which is explained schematically with reference to FIG. 4, but this is only about 100 msec at the speeds mentioned above. Accordingly, the planetary wheel plate 62 must rotate at approximately 600 to 1200 revolutions / min.

Due to the fact that the bottle 1 rotates during code opening, the preferred principle known from the mentioned EP-A 0 079 473 is used in a very simple way, according to which the division matrix 76 and Bottle a relative movement is generated.

The position detection and shooting arrangement shown schematically in FIG. 4 is shown schematically in FIG. 3 at 82.

As has been mentioned, it is customary, in addition to the usage cycle code, to also encode further information on such bottles, such as with regard to the filling material, production data, etc. If such additional information is also applied along the surface of the bottle and not on the bottom or in the neck area of the bottle , it is easily possible, during the rotation of the bottle on the planet gear plate 62, not only the position of the last use cycles - 4, but to read the entire code running through and at the same time to detect where the change in information regarding the number of use cycles is to be applied. In certain cases, the additional information mentioned is applied to the bottle 1 on the bottom and / or collar 37. Such a code is then preferably read on another star wheel, as shown in FIG. 1 for example at 84, by means of reflection and / or transmission detection from below and / or above the bottle, depending on the marking and detection technique with non-rotating bottle. If the bottle also has to be moved past a reading head for this purpose, this is preferably also done on the carousel wheel 27.

Reading and interpreting the code with all possible information mentioned is preferably carried out today when the bottle is absolutely stationary, as at 84 in FIG. 1, and the position determination of the usage cycle code and its change during the bottle rotation on the planet wheel plate 62.

With the code detection at 84, damage to the bottle, such as cracks or impermissible contamination, is also detected and such a bottle is ejected later using a counting technique. A guide for the piece goods, such as the bottles, is shown at 86 in FIG. 1. Such guides are installed wherever the bottles are not guided on two sides by star wheels. This also along the Screw conveyors, as indicated schematically. The other guides are not shown in FIG. 1 for reasons of clarity.

In particular with regard to plastic bottles, such as PET bottles, it is essential to have controls and therefore information about how often such a bottle has been used again. For example, plastic tends to become brittle slowly after multiple sterilization or cleaning. This process arises because, in order to maintain a high transparency of a plastic bottle, the plastic must be processed or injected in the manufacture of the bottle so that it remains as amorphous as possible. During the repeated cleaning or sterilization processes at elevated temperature, the plastic is rearranged from amorphous to crystalline, which can reduce the transparency of the bottle after a certain time. The plastic also becomes brittle with increased crystallinity, so that certain properties, such as, for example, the minimum burst pressure of the bottle, impact strength, etc., are worsened. In practice, it has been found that plastic bottles of this type can pass through in the range between 30 to 50 use cycles before being sent for recycling, for example, where the plastic is melted down and processed into new bottles. Of course, the number of permissible usage cycles depends on various factors, such as the climate in which the bottle is used, the size of the bottle, the product filled into the bottle, etc. With reference to the sensor shown in FIG. 1 at 84, for example for a transmitted light code reading, it can preferably and, as mentioned, also be detected whether the bottle is damaged, contaminated or inadmissibly milky. If such an impermissible bottle is detected, this bottle is eliminated at any later point in time by means of a counter arrangement.

It is further a matter of course that the arrangement shown can also be made simpler, for example by the arrangement for the step promotion comprising only two star wheels and one carousel star wheel. It is also possible to arrange other test stations, for example for volume testing, density testing, residual content testing using a content gas analysis etc.

Claims

Claims:

1. Transport method for piece goods (1) occurring in a stream to and from at least one work station (84, 27) for at least one piece goods each, the piece goods being conveyed continuously before and after the work station (5, 5a), thereby ge ¬ indicates that funding is carried out discontinuously at least by the work station (9, 84, 27) in funding steps.

2. Transport device for carrying out the method according to claim 1, characterized in that before and / or after the work station (84, 27) a continuously operated first conveyor (5, 5a) is provided and this downstream and / or upstream a second conveyor device (15, 29, 31, 27, 17) synchronized with it and operated intermittently.

3. Transport device according to claim 2, characterized ge indicates that the first conveyor (5, 5a), the second (15, 29, 31, 27, 17) immediately upstream and / or downstream, a screw conveyor arrangement (5, 5a).

4. Transport device according to claim 3, characterized ge indicates that the conveying speed of the piece goods (1) towards the second conveyor (15, 29, 31, 27, 17) and / or away from the latter by variation of the screw train (7) Slope is changed, in particular increased and reduced away.

5. Transport device according to one of claims 2 to 4, characterized in that the second conveying device of the first (5, 5a) is connected immediately after and / or upstream of a takeover (15) or transfer (17). Star wheel includes.

6. Transport device according to one of claims 2 to 5, characterized in that at least in ei¬ ner takeover and / or transfer phase during which a piece goods from the first conveyor (5) to the second (15, 29, 31, 27 is transferred, or, 17) taken from the first (5a) from the second (15, 29, 31, 27, 17), the feed rate ei¬ ner the unit load ^'the receiving (25) and / or überge¬ inputting (25) Batch of the second conveyor (15, 17) in a directional component and corresponding amount, at least substantially equal to a directional component or its amount, a transferring (7) and / or receiving (7a) batch of the first conveyor (5, 5a) is.

7. Use of the transport device according to one of claims 2 to 6 for plastic bottles as piece good,

8. A method for determining the position and / or for reading and / or applying a marking from or onto piece goods (1) (1) which are or are generated in a stream, characterized in that a transport method according to claim 1 is used is and the position determination, reading and / or applying the marking is carried out during at least one standstill phase of the funding steps.

9. The method according to claim 8, characterized in that for reading and / or attaching and / or for determining the position, the piece goods (1) and an arrangement therefor (72, 78, 68) at least in the standstill phase of the conveying steps into one Relative movement can be offset.

10. The method according to claim 9 for rotating body-shaped piece goods (1), characterized in that the relative movement is realized by rotating the piece goods (1) about their axis.

11. The method according to any one of claims 9 or 10, characterized in that in the same standstill phase, at least the position determination of a certain marking and a marking is carried out, with rotation of the piece goods, both within a maximum of two revolutions.

12. The method according to any one of claims 8 to 11, characterized in that a laser marking is carried out.

13. The method as claimed in one of claims 9 to 12, characterized in that a marking is carried out by means of a laser beam, which is divided into a beam by a beam splitter, such as a lattice-like matrix, and a relative movement by the relative movement is created between the beam and the piece goods.

-14. Method according to one of claims 10 to 13, characterized in that a respective piece goods before the standstill phase is brought into frictional engagement with a rotating rotary actuator (62) and the relative rotational movement of plate (62) and piece goods (1) is reduced when the frictional engagement is created.

15. System for performing the method according to one of claims 8 to 14, - characterized in that a transport device according to one of claims 2 to 6 is provided and at least one station for position determination and / or application and / or reading at least one is called work station.

16. Plant according to claim 15, characterized in that the second conveying device comprises a star wheel (27), with receptacles each for a piece goods (1), that further along the piece goods movement path caused by the star wheel (27) at least one work station (82 ) is provided, in a position that is assumed by a respective receptacle for the piece goods (1) in a respective standstill phase of the conveying steps of the star wheel (27), and that at least in this position a drive device (62, 64, 54) is provided for the piece goods (1) and / or the work station, which drives the piece goods relative to the work station, preferably in a rotational movement.

17. The system according to claim 16, characterized in that the drive device comprises a continuously rotating sun gear, coaxial to the star gear, with a number of planetary friction wheels (62) corresponding to the number of recordings, and- that A controllable .Lowering and .Lifting device (41, 43, 46) is provided for the engagement of piece goods (1) with a respective planetary friction wheel (62).

18. Plant according to claim 17, characterized in that the direction of rotation of the sun wheel (54) and the feed movement of the star wheel (27) are aligned and that the engagement of piece goods and planetary friction wheel (62) during a feed phase of the star wheel (27 ) he follows.

19. System according to one of claims 15 to 18, characterized in that the work station comprises a controlled laser source (72) with an output-side beam splitter for generating a laser beam, the laser beam being stationary with respect to the laser source and by means of the drive device creates a relative movement between the piece goods and the laser beam during the application of a marking.

20. System according to one of claims 15 to 19, characterized in that the work station comprises a position detection device and a laser source, on the one hand for position detection of an existing marking, on the other hand for applying a marking, and that for controlling the laser source via a Time control (70) and / or via a position control, preferably with a controlled, angle-variable deflection mirror for the laser beam (78), which is connected on the input side to the position detection device.

21. System according to claim 20, characterized in that the piece goods are set in rotary motion and a marking position detection and an application of a marking position direction takes place in at most two revolutions of the piece goods.

22. Use of the method or system according to one of claims 8 to 13 or 14 to 20 for plastic bottles, in particular PET plastic bottles.

23. A method for applying a code marking to a moving plastic bottle, in which a laser beam is divided into a laser beam bundle by a beam splitter and a relative movement is created between the laser beam bundle and the plastic bottle, characterized in that the bottle movement is used for this purpose.