Device and method for reducing the speed of a container flow in a container treatment plant

Abstract

Transport device for reducing the speed of a container stream in a container treatment plant with at least one dividing screw (150), wherein the dividing screw (150) has a free rotation (155) in its inlet; comprising a conveyor belt (130) or a conveyor chain (130) which is arranged at least along the entire length of the dividing screw (150) in such a way that containers (105) engaging with the dividing screw (150) stand thereon; a drive for the conveyor belt (130) or the conveyor chain (130) and a control and / or regulating device which is designed to control and / or regulate the drive in such a way that the conveyor belt (130) or the conveyor chain (130) rotates synchronously with a speed of the containers (105) at the outlet of the dividing screw (150); comprising a transfer star (114, 214), wherein the transfer star (114, 214) is arranged at the inlet of the dividing screw (150) in such a way that containers (105) in engagement with the transfer star (114, 214) are brought into engagement with the freely rotating part (155) of the dividing screw (150) and placed on the conveyor belt (130) or the conveyor chain (130).

Description

Field of the InventionThe present invention relates to a transport device and a method for reducing the speed or separating delay of a container stream in a container treatment plant having a separating screw.Prior ArtIn container treatment installations, containers, such as bottles, cans or the like, are treated in one or more successive process steps. A subunit of a container treatment plant, a so-called block, can comprise, for example, a filling unit for filling the containers, a labeling device, an inspection unit and / or a packaging unit for forming and packaging container containers. In this case, the containers to be treated are generally transported and treated in the various treatment units as continuous container streams at different speeds, which are predefined by the design and technology of the respective treatment unit.Thus, in order to guarantee the continuity of the entire container flow through the subunit, the containers must be transported at different pitches, i.e. intervals of successive containers, in different sections of a transport device connecting the treatment units, due to their different speeds.For example, when individual containers, such as filled bottles, are combined and packaged, these containers are generally conveyed one after the other over a predefined transport path by a treatment unit, for example a filling unit or a labeling device, in order to be further treated and / or combined into bundles and / or packaged in another way in subsequent processing stages. The high transport speed present at the outlet of the filling unit or labeling device requires a relatively complicated container handling and / or container handling, which can easily lead to errors or disturbances of the process sequence. The transport of the containers per se is also relatively susceptible to problems.In order to avoid the above-described problems, the containers are therefore generally decelerated from an inlet pitch corresponding to the upstream treatment unit to an outlet pitch corresponding to the downstream treatment unit by means of a dividing screw with decreasing pitch, i.e. decreasing distance between adjacent thread notches, whereby a speed reduction or a division delay of the container stream passing through the dividing screw is achieved. The division worm must be longer the greater the difference between the inlet division and the outlet division. Particularly when fanning out a single-track container stream, for example by means of a sorting device, into a plurality of container streams and subsequently combining the containers of the respective container streams to form bundles, considerable separation differences can arise, which can only be insufficiently bridged by a single dividing screw. In this case, constructions with brake elements or passage locks are frequently proposed in the prior art in a complicated manner in order to bridge such division differences. The published patent application DE 41 28 733 A1 shows a transport method for piece goods occurring in a stream, a transport device for this, a method for determining the position of a marking by means of such a transport method and a system for this. A bottle is conveyed forward linearly by a screw, while a starwheel shortly thereafter from a standstill phase with a conveying step will take over the bottle at the transition from a thread draw into a pin. However, the pin is located at the outlet of the screw. An output star wheel, which delivers the bottles individually to the conveying screw, transfers the bottles directly to the thread so that no single bottle comes into contact with the spindle. US 48 34 826 A describes a method and an apparatus for melt-cutting a label by blowing hot air against the label, which consists of a heat-shrinkable tube closely adhering to the periphery of a bottle or the like. European patent application EP 0 798 262 A1 is directed to a machine for filling containers with liquids. The machine consists of a housing in which are accommodated drive means with cantilevered support means projecting from the housing. These supporting means carry a conveyor line for moving the containers to be filled and a separating device for the same containers, which is located downstream of the conveyor line. The laid-open specification DE 34 19 039 A1 describes an apparatus for separating, inverting and arranging elongated articles of goods which emerge from a production machine in a longitudinal or transverse manner. Two adjacent conveyor screws are tapered on their inlet side so that the pieces of goods can easily pass between the two screws. This entry of the screw flights simultaneously causes the individual items to be removed from the stock of items in the pile. The pieces of goods are guided linearly between the conveying screws. The published patent application DE 38 02 463 A1 discusses a device in which the respective vessels can be brought to a large distance from one another with relatively simple means for the purpose of a specific inspection and, for the further examinations, in which a smaller distance from one another is sufficient, can be guided through the machine much closer to one another. For this purpose, the bottles are fed to a metering screw in a closed and / or certain spaced-apart row formation and are brought therein to an enlarged distance from one another and fed at this distance to an inspection device and subsequently again continuously reformed in an inversely oriented metering screw to the other distance required for the further treatment or the further transport. In JP S58-162 423 A, a plurality of stages of timing screws in the height direction of an object are installed in a feeding and unloading apparatus. The bottles conveyed on a conveyor are fed into the timing screws which are successively synchronously driven, and the side portion of the bottle is engaged with the guide grooves of the timing screws and separately held at the guide groove pitch and conveyed at a prescribed speed. Since the guide grooves of the control screws are separated in the vertical direction, the bottles are held at two positions in the vertical direction.It is therefore the object of the present invention to provide a device and a method for transporting containers in a container treatment plant which makes it possible to bring containers as quickly as possible to a low transport speed and to transport them largely without problems from a first treatment unit, for example a labeling device, to a further treatment unit, for example a packaging device.DESCRIPTION OF THE INVENTIONThe invention provides a transport device for reducing the speed of a container stream in a container treatment plant according to claim 1. Preferred embodiments are described in the dependent claims.Single-screw feeders as means for adjusting a pitch of a generally single-track container stream are well known in the art. In this case, containers are fed to the dividing screw at their inlet at a predetermined inlet division and inlet speed. The containers are generally received individually by a thread of the dividing screw and, due to a rotation of the dividing screw, are guided at a predetermined rotational speed along the dividing screw to the outlet thereof. Due to a decreasing or increasing division or pitch of the dividing screw, the division of the container stream is increased or decreased. Decisive for the division of the discharged container stream is the division of the last pass of the indexing screw at its outlet.Here and in the following, a pitch of a thread of a dividing screw is to be understood as a distance between adjacent thread notches. The pitch is understood to mean the path of the thread which is covered by one revolution. In the case of single-start threads, the pitch corresponds to the pitch. For multiple-start, such as the double-start threads used for sorting, the pitch is divided by the number of turns. The embodiments described below can be realized with single-start as well as multiple-start single-screw devices. When multi-speed single-feed screws are used, the rotational speed of the single-feed screw may have to be reduced due to the correspondingly greater pitch in order to obtain a desired discharge speed of the containers. For the sake of simplicity of illustration, it is assumed below without restriction that the single-screw elements used are single-screw single-screw elements.Unlike in the case of known single-part screws which completely implement the speed reduction by means of a decreasing division, the single-part screw according to the invention has a free rotation at its inlet, i.e. a section without a thread. In this part of the indexing screw, the indexing screw can rotate freely without receiving a container. Likewise, containers that engage, i.e., are in mechanical contact, with the indexing screw can be freely slid along a longitudinal axis of the indexing screw. In particular, an entering container can slide along the freely rotating part of the indexing screw at its entry speed, in order to then abruptly lose its excess kinetic energy when it strikes the flanks of the first pass, i.e. the first thread turn. Here, the excess kinetic energy denotes the kinetic energy to be associated with the speed difference between the inlet speed and the outlet speed. A portion of this energy can be dissipated by friction by selecting materials with suitable coefficients of friction for the surface of the freely rotating part of the indexing screw, such as low-wear plastics, even before they strike the flanks of the first pass.The cross-sectional shape of the freely rotating part of the single-part screw is arbitrary as long as it is rotationally symmetrical about the longitudinal axis of the single-part screw, i.e. in particular has no thread. In the simplest case, it can be a cylindrical free rotation, wherein the diameter of the cylinder preferably corresponds to the core diameter, i.e. the minimum diameter, of the subsequent first pass. However, a cone shape, the shape of a half hyperboloid, a bell shape or the like is also conceivable. The corresponding shape is preferably arranged such that its increasing or decreasing diameter continuously merges into the core diameter of the first pass. When using a transfer star for transferring the containers to the freely rotating part of the indexing screw (see below), for example a cone or hyperboloid with decreasing diameter can be used for shortening the minimum length of the freely rotating part (see also below). Conversely, a freely rotating part with a diameter increasing along the free rotation, in particular when using lateral counter-clamping elements along the free rotation, for example laterally spring-mounted guide elements, can be used for braking the container movement along the free rotation.The type of thread of the metering screw, in particular the shape of the threaded notch or of the thread turn and of the thread flanks, can be predefined as a function of the container shape to be conveyed. For example, trapezoidal threads, rounded trapezoidal threads or round threads are conceivable. Depending on the shape of the thread, the thread of the screw-in part can be brought into engagement with a rotationally symmetrical section of a container, for example a closure cap, a bottle neck, a can cross section or the like, or else, with a corresponding orientation of the container during the feed to the screw-in part, with a non-rotationally symmetrical section of the container, for example with a section with an oval cross section. For conveying bottles or bottle-like containers, the indexing screw can generally be brought into engagement with the tapered portion of the bottle. It must be taken into account here that the pitch of the indexing screw must not fall below the maximum diameter of the containers in engagement in the conveying direction. The pitch of each thread turn further corresponds at least to the diameter of the engaged portion of the container in the conveying direction.From the above it follows that the dividing screw is generally used specifically for a container shape and size to be transported as well as a specific outlet division. In the event of a product change which requires a different container type, the dividing screw generally has to be changed. Due to the free rotation in the inlet of the dividing screw, however, a certain flexibility arises with regard to the inlet division or inlet speed. A dividing screw provided with a free rotation can thus convey an incoming container stream with an inlet division lying in a predetermined range.According to a further development, the dividing screw can have a constant division. In this case, the speed reduction between the incoming container stream and the outgoing container stream takes place completely in the region of the freely rotating part of the indexing screw. In this further development, the containers are thus guided at a constant speed only along the thread of the dividing screw, so that this part of the dividing screw can be shortened considerably. For example, a dividing screw with a length of typically 700-1100 mm can be shortened to 250-350 mm without free rotation due to the development according to the invention with free rotation. As a result, the entire system can be designed more compact or the single-part worm can also be used at locations at which the previously known single-part worm, whether its length could not be used.According to an alternative development, the dividing screw can also have a division decreasing from its inlet to its outlet. Thus, in addition to the speed reduction or pitch distortion due to the free rotation of the single-part screw, a further pitch distortion takes place along the thread of the single-part screw. The combined pitch delay can thereby bridge considerable differences between the inlet pitch and the outlet pitch, as can occur, for example, when fanning out a single-track container stream onto a plurality of container streams and in sorting methods. For example, with such a single-part screw, a pitch delay of 300 mm inlet pitch to 100 mm outlet pitch is possible without high susceptibility to faults.According to a further development, the dividing screw can be designed to reduce a division of an incoming container stream from an inlet division to an outlet division of an outgoing container stream, wherein a length of the free rotation, along the longitudinal axis of the dividing screw, is at least one length which is calculated from the sum of the difference of the inlet division minus the outlet division and a diameter of the containers to be transported. The diameter of the containers to be transported corresponds to the maximum diameter of the containers to be transported in the conveying direction. The minimum value indicated above can be reduced if the dividing screw has a thread with decreasing pitch, as in the preceding embodiment. In this case, the minimum value corresponds to the sum of the difference of the lead-in pitch minus the pitch of the first thread and the diameter of the containers to be transported. The container diameter is taken into account in the minimum values mentioned, since the container, when transferred by a transfer star to the freely rotating part of the indexing screw, must first be released by further rotating the transfer star before a indexing draft can begin. Such a release occurs by further turning the transfer star by 10° to 15°, which approximately corresponds to the container diameter. As already mentioned above, this minimum value can be further reduced if instead of a cylindrical free rotation with a constant diameter a free rotation with a decreasing diameter, for example in the form of a half hyperboloid, is used. As a result of the decreasing diameter, the container in engagement with the transfer star is released already at a smaller angle than in the case of a cylindrical free rotation.According to a further development, a length of the free rotation can be at least 80 mm, preferably at least 100 mm, particularly preferably at least 120 mm. A greater length allows to cover a greater range of lead-in pitches compatible with the desired lead-out pitch according to the formula described above. With a suitable selection of the length of the free rotation, the same dividing screw can be used for a predetermined inlet division and twice this division, whereby it is possible to switch flexibly between a simple container flow and a sorting. In order to transition from a further transport of the entire incoming container stream by the dividing screw to a sorting in which only every other container is to be transported further by the dividing screw, the rotational speed of the transfer star, with which the containers are transferred to the dividing screw, can be doubled, for example, while the rotational speed of the dividing screw remains constant.The transport device further comprises a transport belt or a transport chain which is arranged at least along the entire length of the single-part screw in such a way that containers which are in engagement with the single-part screw stand thereon. The transport belt or transport chain is designed to be revolving, wherein the containers stand with their container bottom on the upper run of the transport belt or transport chain during transport by the dividing screw. For this purpose, the transport belt or transport chain can be arranged parallel to the indexing screw at a distance which depends on the height of the containers to be transported and the location of the containers at which the thread of the indexing screw engages. In order to be able to handle different container types or heights, the transport belt or the transport chain and / or the dividing screw can be designed to be displaceable relative to one another. Preferably, the containers are thus transported upright along the dividing screw. The transport belt or transport chain extends at least over the entire length of the dividing screw. Thus, containers can be placed on the conveyor belt or the conveyor chain immediately when they are brought into engagement with the dividing screw. The surface or the material of the transport belt or of the transport chain can be selected in such a way that the containers to be transported can slide or slide along the free rotation of the dividing screw over the transport belt or the transport chain without tilting. For example, a non-slip-resistant plastic surface or a metal surface is conceivable. In the case of metal surfaces, a lubricant can additionally be used (dry or wet lubrication).The transport device further comprises a drive for the transport belt or the transport chain and a control and / or regulating device which is designed to control and / or regulate the drive in such a way that the transport belt or the transport chain rotates synchronously at a speed of the containers at the outlet of the dividing screw. Drives and control and / or regulating devices for conveyor belts or chains are well known in the art and will therefore not be explained in further detail here. Driven by the regulated or controlled drive, the transport belt or transport chain rotates according to this development at a constant speed which corresponds to the speed of the containers at the outlet of the dividing screw. The control and / or regulating device can also control and / or regulate a drive which rotates the dividing worm. In this case, either the rotational speed of the transport belt or of the transport chain is adapted to the rotational speed of the indexing screw, or conversely the rotational speed of the indexing screw is adapted to the rotational speed of the transport belt or of the transport chain. In any case, the rotational speed of the conveyor belt or of the conveyor chain corresponds to the discharge speed of the containers due to the rotation of the indexing screw, so that the containers can be released from the indexing screw without the risk of tilting.Alternatively to the above-described developments, an inverted single-part worm is also conceivable, which, instead of a free rotation at its inlet, has such a free rotation at its outlet. In this case, the transport belt or transport chain can rotate at a greater speed than the speed of the containers at the outlet of the indexing screw, so that the containers are accelerated along the free rotation of the indexing screw in the outlet by means of friction with the transport belt or transport chain. In this way, a discharge pitch of the indexing screw can be moved apart along the free rotation. This can be effected, for example, in an inlet to a labeling device.Since the transport belt or transport chain rotates according to the above development at a speed which corresponds to the speed of the containers at the outlet of the dividing screw, the speed of the transport belt or transport chain is thus lower than the speed of the containers at the inlet of the dividing screw. The transport belt or transport chain thus acts in a delaying manner on the container movement at the inlet of the dividing screw due to the friction with the containers standing on the transport belt or transport chain. By sliding or sliding the container bottoms over the surface of the conveyor belt or of the conveyor chain, a portion of the excess kinetic energy of the containers is thus already dissipated before the containers are braked to the respective pitch of the first pass by abutting the first pass of the indexing screw. In this case, the surface can be selected, as described above, in such a way that tilting of the containers can be avoided.The transport device further comprises a transfer star, which is arranged at the inlet of the indexing screw in such a way that containers in engagement with the transfer star can be brought into engagement with the freely rotating part of the indexing screw and placed on the transport belt or the transport chain. Transfer stars for transferring containers from a treatment unit such as a rotary machine to a dividing screw are known in the prior art. The transfer stars are arranged in such a way that the respective dividing worm is arranged tangentially on the circumference of the transfer star. In the present development as well, this is the case, wherein the transfer star is additionally arranged with respect to the indexing screw in such a way that the containers transported by the transfer star can be brought into engagement with the freely rotating part of the indexing screw. Preferably, the transfer to the freely rotating part of the indexing screw can already take place at the beginning, with respect to the inlet of the indexing screw, of the freely rotating part. The transfer star can furthermore be arranged in such a way that the bases of the containers transported by it are level with the transport belt or the transport chain, so that the containers in engagement with the transfer star can be placed on the transport belt or the transport chain without problems.According to a further development, a curved guide element can be arranged on the circumference along a segment of the transfer star in such a way that containers which are in engagement with the transfer star can be guided along the curved guide element as far as the freely rotating part of the indexing screw. The segment of the transfer star can be a quarter circle segment which extends 90° from the freely rotating part of the indexing screw along the circumference of the transfer star opposite to the direction of rotation thereof. Thus, between the guide element arranged along this segment and the transfer star, the containers in engagement with the transfer star can be safely guided until they are transferred to the freely rotating part of the dividing screw. Guide members which can be used are, for example, guide rails, guide plates or other guide elements known in the prior art. The guide element can be arranged in such a way that its edge running out to the dividing screw lies in a plan view in alignment with the surface of the freely rotating part of the dividing screw.According to a further development, the transport device can furthermore comprise a rectilinear guide element which is arranged parallel to the indexing screw, wherein the rectilinear guide element can extend in particular at least over the freely rotating part and a first pass of the indexing screw. The rectilinear guide element can be arranged in such a way that the containers transported by the dividing screw can be guided stably between the dividing screw and the guide element. Since inertial forces act on the container in the region of the freely rotating part of the indexing screw, in particular because of the speed difference between the transport belt or transport chain and container, the use of such a guide element increases the stability of the container guide. In particular, the rectilinear guide element can be arranged along the entire length of the dividing screw. Here too, guide rails, guide plates or other guide elements known in the prior art are conceivable. In a special development, a straight guide element can be arranged parallel to the indexing screw at the height of the indexing screw itself, in order to be able to stably guide the section of the container which is in engagement with the indexing screw.According to a further development, the transport device can furthermore comprise at least a first and a second metering screw, wherein the second metering screw likewise has a free rotation and has the same pitch as the first metering screw, but a thread width different from a thread width of the first metering screw, and wherein the second metering screw is arranged parallel to the first metering screw in such a way that the free rotations of the first and the second metering screw overlap at least partially and a container which is in engagement with the first metering screw and which has a first container section can be in engagement with the second metering screw and has a second container section.In the simplest embodiment, the transport device described above comprises only one dividing screw according to the invention. For better stabilization of the transported containers, the transport device can however comprise at least one further, second indexing screw which is constructed similarly to the first indexing screw. The second metering screw likewise has a free rotation in its inlet and is arranged parallel to the first metering screw. In particular, the second single-part worm can be arranged vertically, with respect to a contact surface of the transport device, displaced with respect to the first single-part worm. The free rotations of the two single-part screws overlap at least partially, so that a container which is in engagement with both the first single-part screw and the second single-part screw can slide or slide along the overlapping free rotations. Preferably, the second free rotation relative to the common transport path of the two single-part screws starts at the same point as the first free rotation, so that a container to be transferred to the single-part screws can be brought into engagement with the two free rotations approximately simultaneously.According to this further development, the second metering screw has the same division as the first metering screw so that containers which are in engagement with both metering screws can be transported synchronously and are not sheared during transport. However, the thread width of the second single-part screw according to this refinement is different from the thread width of the first single-part screw. Thread width is to be understood here and in the following as a maximum width, measured in the conveying direction, of the engagement formed by the thread for the container to be transported. For the case of straight or concave, i.e. exclusively positively curved, flanks, the thread width is given by the maximum spacing of the flanks of the respective thread. In other words, single-flighted worms of greater threadline width can accommodate containers of greater cross-sectional diameter.Such an arrangement is particularly suitable for the stable speed reduction of containers, such as bottles, which taper along a longitudinal axis. For example, a first single-part screw having a small thread width may be engaged with the bottle necks or closures, while a second single-part screw having a larger thread width may be engaged with the bottle cups. Thus, the bottle is securely held at two locations during transport so that it cannot tilt. It should be noted that equal pitches but different thread widths can be realized by correspondingly different flank widths. A larger thread pitch width of the second metering screw can also lead to a correspondingly shortened free rotation in the inlet of the second metering screw.According to a further development, the transport device can furthermore comprise a synchronous drive of the first and second metering worm, which is designed to drive the first and second metering worm at the same rotational speed. Since different rotational speeds of the first and second dividing worm would inevitably lead to a warping and possibly to breakage of the conveyed containers due to the same division, according to this refinement the transport device preferably has a common, synchronous drive of the first and second dividing worm. Such a synchronous drive can be realized, for example, by means of a common drive motor and gears with fixed transmission ratios.The above-mentioned object is also achieved by a container treatment system for treating containers in the beverage processing industry, which comprises a first treatment unit, in particular a labeling device, for treating a container stream and a second treatment unit, in particular a shrink sleeve assembly, for further treatment of the container stream, wherein a transport device according to the above-described developments for transporting the containers is arranged between the first and the second treatment unit, and wherein the transport device is configured to adapt an inlet division of the container stream, which is predetermined depending on the first treatment unit, to an outlet division of the container stream, which is predetermined depending on the second treatment unit.The same variations and refinements, which were described above in connection with the transport device, can also be used here. In particular, the transport device can be designed to reduce a container division of a labeling machine to a container division of a subsequent shrink sleeve assembly. By means of the transport device, containers can thus be supplied to the shrink sleeve assembly at a pitch required for the application of shrink sleeves. Other combinations of treatment units with different machine parts, such as a filling station and a labeling device, can be linked analogously to the transport device according to the invention.The object is likewise achieved by a dividing screw for dividing a container stream, which is characterized in that the dividing screw has a free rotation, in particular a free rotation with a length of at least 80 mm, preferably at least 100 mm, particularly preferably at least 120 mm, in its inlet. Here too, the same variations and developments as described above in connection with the single-screw feeder of the embodiments of the transport device can be used.Finally, the above-mentioned object is also achieved by a method for the division-draft of a container stream by means of a division screw, which comprises the steps:supplying the container stream at a predetermined inlet pitch to an inlet of the dividing screw configured with a free rotation;controlled rotation of the indexing screw at a rotational speed determined in dependence on a predetermined discharge speed of the conveyed containers and a discharge pitch of the indexing screw; andsynchronously driving a revolving transport belt or a revolving transport chain at the predetermined discharge speed,wherein the conveyor belt or the conveyor chain is arranged at least along the entire length of the indexing screw such that containers engaging the indexing screw stand thereon.Again, the same variations and developments described above in connection with the transport device according to the invention can also be applied to the method for dividing a container stream. In particular, the feeding of the container stream can be effected by means of a transfer star which, as described above, is arranged at the inlet of the dividing screw. The pitch of the indexing screw can be constant or variable, wherein in the last case the discharge pitch is determined by the pitch of the last pass of the indexing screw. The delivery speed and the delivery pitch are given by the requirement of the subsequent treatment unit.With the described devices and methods, a container stream can be merged extremely effectively and without problems from a larger inlet division to a smaller outlet division. In this case, the kinetic energy of the containers, which is excess due to the correspondingly higher inlet speed, is dissipated over a short distance by means of the free rotation of the dividing screw and of the transport belt or of the transport chain, which enables a more compact construction of the plant. In addition, installation costs are lower due to the shorter and simpler single-part worms. Furthermore, an exchange of the dividing screw is only required when the discharge pitch changes, which reduces the operating costs.Further features and exemplary embodiments and advantages of the present invention are explained in more detail below with reference to the drawings. It should be understood that the embodiments do not exhaust the scope of the present invention. It is furthermore understood that some or all of the features described below can also be combined with one another in another manner. FIG. 1 illustrates an exemplary embodiment of a container treatment plant with a transport device according to the present invention. FIG. 2 illustrates an exemplary embodiment of a free-wheeling single screw according to the present invention in plan view.In the figures described below, like reference numerals designate like elements. For clarity, like elements will be described only at their first instance. However, it is understood that the variants and embodiments of an element described with reference to one of the figures can also be applied to the corresponding elements in the other figures.FIG. 1 illustrates an exemplary embodiment of a container treatment plant 100 having a transport device for the division delay of a container stream. In this non-limiting embodiment, the transport device connects a rotary machine 110 to a shrink sleeve assembly 160. Along the rotary machine 110, the containers 105 rotate at a machine speed V M which is predetermined by a processing speed of a labeling device 116 arranged in the periphery of the rotary machine 110. The labels applied by the labeling device 116 to the containers 105 are pressed onto the containers by a pressing station 118.In order to be able to feed the containers 105 from an incoming container stream, in which the containers are transported edge to edge on a conveyor belt 120, to the rotary machine 110, the container treatment plant 100 has an inlet star 112 and an upstream dividing worm 140 with increasing division. The upstream metering screw 140 receives the containers 105 and accelerates them in such a way that their distance at the outlet of the metering screw 140 corresponds to the division of the inlet star 112. In this case, the conveyor belt can rotate at a speed V E which corresponds to the machine speed V M or is greater than this.From the rotary machine 110, the labeled containers are transferred to an outlet star 114 in order to transport them further to a downstream shrink sleeve assembly 160. Shrink sleeves are shot onto the containers 105, in particular onto bottles, by means of the shrink sleeve assembly 160. For this purpose, however, the container stream treated by the aggregate must only move at an outflow speed V A which is, for example, half as great as the machine speed V M. Accordingly, the division of the container stream from the machine division of the rotary machine 110 must be reduced to a discharge division half as large. For this purpose, the transfer star 114 transfers the containers received by the rotary machine 110 to a dividing screw 150 which, according to the invention, has a free rotation 155 at its inlet. In the illustrated, non-limiting example, the free rotation 155 is cylindrical and has the length y, while the total length of the dividing screw 150 is given by x.The dividing screw is arranged at a tangential distance from the transfer star 114 in order to receive containers therefrom at the beginning of the free rotation 155. During the transfer, the containers received first continue to have the machine speed V M, wherein they are simultaneously placed on the conveyor belt 130 rotating at the discharge speed V A. Due to the speed difference, the containers slide or slide along the free rotation 155 over the surface of the conveyor belt 130, a part of their kinetic energy being dissipated by friction. Finally, however, the containers are braked to the discharge speed V A when they strike the flanks of the first pass of the thread of the indexing screw 150. Since the containers have thus already reached their final speed V A after the first pass, the dividing screw 150 can be formed substantially shorter than the dividing screw 140 known in the prior art. The dividing screw 150 illustrated here has a constant division. However, metering screws are also conceivable whose division decreases toward the outlet in order to bring about a further speed reduction.The rotational speeds of the conveyor belts 120 and 130 can be predetermined independently of one another, but depending on the throughput of the respective subsequent treatment unit. However, the transport path 130 and the dividing screw 150 are generally operated synchronously, so that the discharge speed of the containers in the last pass of the dividing screw 150 due to the rotation thereof corresponds to the rotational speed V A of the transport belt 130.FIG. 2 shows a detailed representation of a transport device with a single-part screw according to the present invention. From a rotary machine 210, the containers 105 are transferred by means of a first transfer star 213 and a second transfer star 214 to the free rotation 155 of the indexing screw 150. This illustration also shows the revolving transport belt or the revolving transport chain 130, it being clear that the transport belt or the transport chain extends beyond the entire length of the dividing screw 150. The dividing worm 150 is held in this embodiment by means of a holder 252 which is adjustable by means of adjusting screws 253 and 254.Furthermore, the figure shows two guide elements for the containers 105. A curved guide plate 270 is arranged along the quarter circle of the transfer star 214 before the transfer to the freely rotating device 155 and merges continuously in its extension into the surface of the freely rotating device 155. As a result, the containers which are in engagement with the transfer star 214 are reliably guided to the freely rotating device 155 and transferred to the latter. Furthermore, a guide rail 280 is arranged parallel to the dividing screw 150, and in particular parallel to its freely rotating part 155, in order to guide the containers securely along the dividing screw 150. The containers can be cans or bottles standing upright on the conveyor belt 130, the upper part of which, in particular the bottle neck, is in engagement with the indexing screw 150 and is guided between the latter and the guide rail 280.The exemplary indexing worm 150 illustrated here has a rounded trapezoidal thread with a constant pitch d. The flanks of the thread have a flat outer profile and have a flank width of length d 1. The thread width, i.e. the maximum distance between the two flanks of a thread 256, is denoted by d 2 in this case. The constant pitch d is obtained as the sum of the flank width d 1 and the thread pitch width d 2. In the present case, the shape of the thread is adapted to a circular container section. Other thread shapes and sizes are conceivable depending on the container type or container shape to be transported.The transport device with a single screw section 150 with a free rotation 155 shown permits a rapid and trouble-free speed reduction of the containers supplied by means of the transfer systems 214. The length of the cylindrical free rotation is at least the sum of the maximum container diameter in the conveying direction and the difference of the inlet pitch minus the outlet pitch. Because of the constant division, the dividing screw 150 can be shortened considerably compared to a known dividing screw.

Claims

Transport device for reducing the speed of a container stream in a container treatment plant having at least one indexing screw (150), wherein the indexing screw (150) has a free rotation (155) in its inlet; comprises a transport belt (130) or a transport chain (130), which is arranged at least along the entire length of the indexing screw (150) such that containers (105) which are in engagement with the indexing screw (150) stand thereon; comprises a drive for the transport belt (130) or the transport chain (130) and comprises a control and / or regulating device which is designed to control and / or regulate the drive such that the transport belt (130) or the transport chain (130) rotates synchronously with a speed of the containers (105) at the outlet of the indexing screw (150); a transfer star (114, 214) comprising, wherein the transfer star (114, 214) is arranged at the inlet of the single-part screw (150) such that containers (105) in engagement with the transfer star (114, 214) are brought into engagement with the freely rotating part (155) of the single-part screw (150) and are placed on the transport belt (130) or the transport chain (130).The transport device according to claim 1, wherein the dividing screw (150) has a constant pitch.The transport device according to claim 1, wherein the dividing screw (150) has a pitch decreasing from its inlet to its outlet.The transport device according to any one of claims 1 to 3, wherein the dividing screw (150) is configured to reduce a division of an incoming container stream from an inlet division to an outlet division of an outgoing container stream; and wherein a length of the free rotation (155) is at least a length calculated from the sum of the difference of the inlet division minus the outlet division and a diameter of the containers (105) to be transported.The transport device according to any one of claims 1 to 4, wherein a length of the free rotation (155) is at least 80 mm.Transport device according to claim 1, wherein a curved guide element (270) is arranged on the circumference along a segment of the transfer star (114, 214) in such a way that containers (105) in engagement with the transfer star (114, 214) can be guided along the curved guide element (270) as far as the freely rotating part (155) of the indexing screw (150).Transport device according to one of the preceding claims, further comprising a rectilinear guide element (280) which is arranged parallel to the indexing screw (150), wherein the rectilinear guide element (280) extends in particular at least over the freely rotating part (155) and a first pass of the indexing screw (150).Transport device according to one of the preceding claims, further comprising at least a first and a second metering screw, wherein the second metering screw also has a free turn and has the same pitch as the first metering screw (150) but a thread width different from a thread width of the first metering screw (150); and wherein the second metering screw is arranged parallel to the first metering screw (150) such that the free turns of the first and the second metering screw at least partially overlap and a container (105) with a first container section in engagement with the first metering screw (150) can be in engagement with the second metering screw with a second container section.The transport device according to claim 8, further comprising a synchronous drive of the first and second dividing worm (150), which is configured to drive the first and second dividing worm (150) at the same rotational speed.Container treatment plant for treating containers in the beverage processing industry, comprising a first treatment unit (116), in particular a labeling device, for treating a container stream and a second treatment unit (160), in particular a shrink sleeve assembly, for further treatment of the container stream, wherein the transport device according to one of the preceding claims is arranged for transporting the containers between the first and the second treatment unit (116, 160); and wherein the transport device is configured to adapt an inlet division of the container stream, which is predetermined depending on the first treatment unit (116), to an outlet division of the container stream, which is predetermined depending on the second treatment unit (160).A dividing screw (150) for dividing a container stream, characterized in that the dividing screw (150) has a free turn (155) with a length of at least 80 mm in its inlet.

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