Device and method for heating plastic preforms and holding device for holding plastic preforms during transport of the plastic preforms

Abstract

Device (1) for heating plastic preforms (10) comprising a transport device (2) which transports the plastic preforms (10) along a predetermined transport path (P), a first transport section (22) along which at least one first heating device (4) is arranged which heats the plastic preforms (10) during their transport along the first transport section (22), and a second transport section (24) along which at least one second heating device (8) is arranged which heats the plastic preforms (10) during their transport along the second transport section (24), characterized in that the device (1) has an alignment device (6) which aligns the plastic preforms (10) with respect to a rotational position with respect to their longitudinal axes (L).wherein this alignment device (6) is arranged along the transport path (P) of the plastic preforms (10) between the first transport section (22) and the second transport section (24).

Description

[0001] The present invention relates to a method and a device for forming plastic preforms into plastic containers. Such methods and devices have long been known from the prior art. In this case, plastic preforms are usually heated in an oven and then formed into the plastic containers using a blow molding machine, such as a stretch blow molding machine. Containers are also known from the prior art which have cross-sections that deviate from circular cross-sections, such as oval cross-sections. For the production of such containers, it is known from the prior art according to document DE 196 08 570 A1 that they are first uniformly heated and then certain regions of the peripheral wall are cooled again in order to ensure that the less warm sections of the wall of the plastic preforms are stretched less.However, this procedure usually requires an additional module that effects this cooling or contact of the plastic preforms.

[0002] A similar manufacturing process of the above-mentioned type is known from the document WO 01 / 68350 A1.

[0003] Furthermore, containers are known from the prior art in which not only the base bodies have a shape deviating from a circular shape, such as an oval shape, but also the corresponding container closures. The closures of oval containers are designed in the same way as those of round bottles. Since the threads of the plastic preforms are usually already in their final shape before the stretch blow molding process, it is necessary to align the plastic preforms in a specific way before they are expanded. Ideally, this alignment is therefore achieved indirectly via the thread, since this is already in its final state and can no longer be deformed.

[0004] The present invention is therefore based on the object of enabling the production of such containers, whereby in particular a special cooling module can be dispensed with.

[0005] This object is achieved according to the invention by the subject matter of independent claims 1, 8 and 9. Advantageous embodiments and further developments are the subject matter of the subclaims.

[0006] A device according to the invention for heating plastic preforms comprises a transport device that transports the plastic preforms along a predetermined transport path. Furthermore, the device comprises a first transport section, along which at least one first heating device is arranged, which heats the plastic preforms during their transport along the first transport section. Furthermore, the device comprises a second transport section, along which at least one second heating device is arranged, which heats the plastic preforms during their transport along the second transport section.

[0007] According to the invention, the device comprises an alignment device that aligns the plastic preforms with respect to a rotational position relative to their longitudinal axes. This alignment device is arranged along the transport path of the plastic preforms between the first transport section and the second transport section. In addition to the term "longitudinal axis," the term "longitudinal direction" is also used below.

[0008] It is therefore proposed within the scope of the invention that such uneven heating of the plastic preforms is not generated by a downstream cooling device acting partially on the preforms, as is known in the prior art, but rather already in the oven that heats the plastic preforms. Since, as mentioned above, alignment of the plastic preforms may be necessary, it is proposed that this be carried out in the aforementioned alignment section, which is located between a first and a second transport section. In this way, it is possible for the plastic preforms to initially be transported along a first transport section and to be heated evenly with regard to their circumferential direction. After alignment has been achieved, the plastic preforms are then heated in a manner that varies along the circumferential direction.

[0009] As explained in more detail below, individual drives can be used to align the plastic preforms. However, since the alignment is only carried out in a limited area of ​​the device, preferably in the area of ​​a deflection wheel, the number of such drives can be reduced. Preferably, the plastic preforms are guided between the first transport section and the second transport section through a deflection area which changes and in particular reverses a transport direction of the plastic preforms. For this purpose, the alignment device can be arranged, for example, on a carrier wheel which reverses the direction of movement of the plastic preforms. Preferably, at least the first transport section or the second transport section runs in a straight line, and particularly preferably both the first transport section and the second transport section run in a straight line.

[0010] In a further advantageous embodiment, the transport device has a rotating carrier and a plurality of transport devices arranged on this carrier. For example, it would be possible for the transport device to have a rotating chain on which a plurality of holding elements for holding the plastic preforms are arranged. These holding elements can be, for example, holding mandrels which are inserted into a mouth of the plastic preforms and can transport the plastic preforms held in this way, in particular through frictional contact. The transport device advantageously transports the plastic preforms individually and preferably also at a constant distance from one another.

[0011] Advantageously, the first and second transport sections are each designed as heating lanes through which the plastic preforms are transported. As mentioned above, the plastic preforms are preferably heated evenly in the first transport section and unevenly in the second transport section. These heating lanes can, for example, have a plurality of heating elements, for example in the form of infrared tubes, which are arranged laterally next to the transport path of the plastic preforms. On the other side of the transport path, reflector elements could be provided, which reflect the infrared radiation back onto the plastic preforms. Such reflector elements could also be provided below the transport path of the plastic preforms.

[0012] In a further advantageous embodiment, the device described here for heating plastic preforms is followed by a blow molding machine and in particular a stretch blow molding machine, which is suitable for blowing or expanding containers which have a cross-section deviating from a circular cross-section.

[0013] In a further advantageous embodiment, the alignment device comprises a carrier rotatable about a predetermined axis of rotation, by means of which the plastic preforms are transported in sections along the transport path and in particular through said deflection area. A plurality of drive devices is preferably arranged on this carrier, with these drive devices particularly preferably each serving to rotate the plastic preforms relative to their longitudinal axis. Therefore, this carrier preferably transports said holding elements along a circular transport path.

[0014] In a further advantageous embodiment, the device comprises a rotational position detection device which detects a rotational position of the plastic preforms relative to their longitudinal axis. This rotational position detection device is advantageously a device which detects a rotational position of the plastic preforms in a contactless manner. For example, this rotational position detection device can comprise a camera or the like. Advantageously, this rotational position detection device is also aligned, in particular, with a threaded region of the plastic preforms and / or a support ring of the plastic preforms and / or detects, in particular, a rotational position of a thread of the plastic preforms or a marking which can be provided, for example, on the support ring.

[0015] This rotational position detection device advantageously outputs at least one signal that is characteristic of a rotational position of the plastic preforms or their threads. In response to this signal, a further element of the alignment device can preferably adjust the rotational position of the plastic preforms. Advantageously, the transport device transports the plastic preforms such that their longitudinal direction runs vertically.

[0016] In a further advantageous embodiment, the device, and in particular the alignment device, comprises a rotating device suitable and intended for effecting individual rotation of the plastic preforms with respect to their longitudinal direction, in particular while the plastic preforms are being transported by the alignment device. In this embodiment, the device comprises at least one rotating device that precisely enables individual rotation of individual plastic preforms.

[0017] In particular, the aim is to create a possibility for different plastic preforms to be rotated by different angles of rotation relative to their longitudinal axis. Advantageously, the rotation device can adjust the rotation of the plastic preforms in response to an output signal from the position detection device. Advantageously, the device further comprises a processor unit that determines a rotation angle by which the individual plastic preforms are rotated relative to their longitudinal direction based on at least one result output by the position detection device.

[0018] In a further advantageous embodiment, the rotating device comprises a plurality of rotary drives, which are arranged in particular on a deflection wheel, in particular on the above-mentioned rotatable carrier. In this way, the individual rotary drives enable individual rotation of individual plastic preforms, in particular depending on the output signal of the position detection device.

[0019] In a further advantageous embodiment, the rotating device comprises a rotary drive and at least one switchable coupling device for transmitting a rotary movement of the rotary drive to holding elements for holding the plastic preforms and / or to an alignment body. This coupling device is preferably arranged between the rotary drive and the holding element so that the rotation of the holding element (with the plastic preform arranged thereon) can be decoupled from the rotation of the rotary drive.

[0020] It would thus be possible for the holding elements to be components of holding devices, for example, rotatable holding spindles, wherein these holding devices preferably also comprise the aforementioned couplings. These holding devices preferably also comprise orientation bodies that are rotatable relative to the longitudinal axis of the plastic preforms, and rotation of these orientation bodies can preferably be decoupled from rotation of the holding elements by means of the aforementioned coupling. Preferably, the aforementioned rotary drives can in turn be mechanically connected to the orientation bodies in order to rotate them (in particular by individual angles of rotation).

[0021] In this way, it is possible for the holding elements to remain connected to the plastic preforms assigned to them even during transport through the alignment device, but the rotational position of the individual holding elements can be individually changed by decoupling. It is possible for this coupling device to effect a coupling and decoupling of the holding element from the rotary drive and / or a coupling and decoupling with the aforementioned orientation bodies by moving at least one coupling element in a longitudinal direction of the plastic preforms.

[0022] In a further advantageous embodiment, the rotating device has an alignment device or an alignment element for aligning the rotating device and / or components of the rotating device, such as in particular but not exclusively the orientation body, in a predetermined rotational position. In addition, an alignment device can also be provided for aligning the holding element or elements, on which the plastic preforms are arranged, in the predetermined rotational position. For example, the orientation body can have a cam, and the alignment device can have a rail element that brings the cam into a specific rotational position. This alignment into a specific rotational position can also be achieved by utilizing the transport movement of the plastic preforms or the transport device.The rail element can, in particular, be a guide rail that runs in sections along the transport path of the plastic preforms. Guide grooves could also be provided through which the cam runs in sections along the transport path.

[0023] In a further advantageous embodiment, the alignment device comprises a plurality of motor drives for rotating the plastic preforms and / or the orientation bodies with respect to their longitudinal direction. These motor drives can be, for example, electric motor drives or servo motors. Advantageously, each plastic preform is assigned such a rotating device (during transport with the alignment device).

[0024] Preferably, rotating devices are arranged in the region of the first transport section and / or in the region of the second transport section, which rotate the plastic preforms about their longitudinal axis. This can involve a uniform rotation of the plastic preforms in the region of the first transport section and an uneven rotation in the region of the second transport section (which thus also enables uneven heating of the plastic preforms in the circumferential direction and thus a temperature profile in the circumferential direction of the plastic preforms).The rotating device in the region of the first transport section can be a (stationary) rack which engages with a gear located on the holding device so that this gear rotates during the transport of the plastic preforms and thus also the holding elements coupled to the gear in this transport section (on which the plastic preforms are arranged) rotate.

[0025] In some cases, prior art devices perform purely mechanical alignment of the plastic preforms. While this may be satisfactory in individual cases, such solutions require additional setup time, for example when changing a die. Furthermore, these solutions are inflexible because, even when alignment is not required, mechanical or manual intervention is required. Furthermore, these known solutions impair performance and are inaccurate. In addition, trim parts are required, and PET abrasion occurs, for example, due to gripping the plastic preform. The reject rate for such solutions is relatively high. Furthermore, the plastic preforms can only be processed reliably if they have a certain notch shape or a certain cam shape (nose).

[0026] Within the scope of an advantageous embodiment, the invention therefore proposes, in particular, optical detection in a deflection region of the device. In addition, as mentioned above, a slip clutch can be provided in order to achieve alignment with a separate motor, in particular a servo stepper motor. In addition, a switchable clutch can also be provided. In addition, the device preferably has an attachable alignment bell as an orientation body, which in turn is driven by the stepper motor or a servo motor. Preferably, as mentioned above, pre-alignment also takes place within the heating device, for example via a cam arranged on the holding device. Furthermore, fine alignment of the rotational position can also be carried out if the thread of the plastic preforms needs to be precisely aligned.

[0027] The present invention is further directed to a holding device for holding plastic preforms during transport of the plastic preforms through a device for heating the plastic preforms. This holding device comprises a holding element which can be inserted into a mouth of the plastic preforms in order to hold them, wherein the holding element is rotatable with respect to a longitudinal direction or longitudinal axis of the plastic preforms, as well as an orientation body which is rotatable with respect to the longitudinal direction or longitudinal axis of the plastic preforms, wherein the orientation body has an alignment element which, during a transport movement of the holding device along a predetermined transport path, enables the orientation body to be aligned with respect to a rotational position with respect to the longitudinal direction of the plastic preforms.

[0028] According to the invention, the holding device has a switchable coupling device in order to couple a rotational movement of the holding element to a rotational movement of the orientation body and / or in order to decouple a rotational movement of the holding element from a rotational movement of the orientation body.

[0029] The holding device described here is particularly suitable in conjunction with the device described above. These holding devices allow the plastic preforms to be aligned without having to remove them from the holding elements, such as holding mandrels, or without having to hold the preform in place.

[0030] The coupling device preferably has two coupling elements which are movable relative to one another in the longitudinal direction of the plastic preforms and which serve to couple and uncouple the rotational movement of the holding element, on the one hand, and of the orientation body, on the other. The orientation body can preferably be coupled to a rotary drive. The orientation body can preferably be coupled to this rotary drive in a defined rotational position, so that the rotational movement of the rotary drive is transmitted to the orientation body. The alignment element described above advantageously also serves to align a rotational position of the orientation body relative to the rotary drive. For example, this alignment element can engage in a corresponding recess in the rotary drive. The holding device advantageously also has a carrier in order to hold the holding element and / or the alignment body rotatably relative to the above-mentioned longitudinal axis of the plastic preforms.to store.

[0031] The present invention further relates to a method for heating plastic preforms. The plastic preforms are first transported along a first transport section and heated during this transport. The plastic preforms are then transported along a second transport section and also heated during this transport. The plastic preforms are heated unevenly with respect to their circumferential direction, at least during their transport along the second transport section.

[0032] According to the invention, the plastic preforms are aligned with respect to a rotational position with respect to their longitudinal direction in an alignment section or an alignment device located between the first transport section and the second transport section.

[0033] Therefore, it is also proposed in the process that the individual plastic preforms be rotated with respect to their longitudinal direction for the purpose of aligning them. Advantageously, individual plastic preforms are individually aligned, so that at least two plastic preforms are rotated by different angles with respect to their longitudinal direction.

[0034] Advantageously, the rotational position of the plastic preforms is detected. Particularly preferably, this rotational position of the plastic preforms is detected optically. Advantageously, alignment occurs after a first heating section or after transport along the first transport section.

[0035] Uneven heating of the plastic preforms with respect to their circumferential direction means that, in particular, the base body of the plastic preform, which is usually arranged below a thread, is heated differently in the circumferential direction. This means that after passing through the heating device, the plastic preforms do not have a constant temperature in their circumferential direction, but rather a temperature profile, i.e., colder and warmer spots. These plastic preforms, heated with a profile in this way, are preferably subsequently fed to a device for forming plastic preforms into plastic containers, which is in particular a stretch blow molding machine.

[0036] Within this device, the more heated areas of the plastic preforms are preferably stretched more strongly, while the less heated areas of the plastic preforms are stretched less strongly. The temperature profile applied during transport is preferably adapted to the position of the mouth or thread of the plastic preforms.

[0037] Advantageously, the rotational position of the plastic preforms and in particular the rotational position of the threads of the plastic preforms and / or another area of ​​the plastic preforms (but in particular an area or a marking whose position is always the same compared to the position of the threads of the plastic preforms) is detected before the actual alignment. It would be conceivable for a marking to be arranged on the support rings of the plastic preforms, which is always characteristic of the rotational position of the threads. However, it would also be possible for holding elements to be aligned with respect to a rotational position first and for the plastic preforms, which are then arranged on the holding elements, to be rotated only subsequently in response to a detected rotational position.

[0038] In a further advantageous embodiment, it is possible for the alignment area to be tapered in one direction, in particular to accommodate an image recording device or a camera. Furthermore, this area can have access means, such as a door, to enable maintenance of the camera, for example.

[0039] The inventive procedures ensure that no reduction in performance is necessary. Furthermore, corresponding systems are very flexible. In a preferred method or a preferred embodiment, the alignment device can be switched off. This means that—if alignment is not required—it can simply be turned off.

[0040] With a procedure using cams, for example, it is possible to configure them once and then call them up again, for example, during a recipe change. In addition, the present invention allows for greater orientation accuracy and reliable alignment, which can also reduce the scrap rate.

[0041] In addition, such a device operates virtually wear-free, as the lifting mechanism occurs during orientation, thus preventing PET abrasion. Since there is no gripping of the plastic preform, damage to the heated support ring can also be avoided. Furthermore, no fittings are required, allowing for changeovers within a very short time.

[0042] The motorized orientation system described here also allows for easy adjustments and readjustments, resulting in a high level of user-friendliness.

[0043] In a preferred embodiment, a feed mechanism for the plastic preforms is also provided, such as a sawtooth inlet. The switchable clutch described here also prevents friction and wear, and advantageously, it also eliminates the need for the belts to engage with a spindle rotation of at least 360°.

[0044] Further advantages and embodiments can be seen from the attached drawings: Showing: Fig. 1 is a schematic representation of an apparatus according to the invention for heating plastic preforms; Fig. 2 a detailed view of the Fig. 1 device for illustrating the orientation of the plastic preforms; Fig. 3 a further detailed representation of the Fig. 1 shown device; Fig. 4 a diagram illustrating a clutch engagement process; Fig. 5 shows a further illustration to illustrate a coupling process; Fig. 6 two representations of holding devices; and Fig. 7 two representations of the coupling device.

[0045] Fig. 1 shows a schematic representation to illustrate the present invention. The reference numeral 1 refers to the device for heating plastic preforms 10. This device 1 has a transport device 2, along which the plastic preforms 10 are transported, more precisely along the transport path P. For this purpose, the plastic preforms 10 are first fed via a feed chute 32 and a synchronizing starwheel 34, then pass through the transport device 2 and are finally taken over by a transfer starwheel 36 and transferred to a blow molding machine (not shown). The transport path P has a first transport section 22 and a second transport section 24. An alignment device 6 is arranged between these two transport sections 22 and 24.

[0046] A plurality of first heating devices 4 are arranged along the first transport section 22, and a plurality of second heating devices 8 are arranged on the second transport section 24. These heating devices can, in particular, be infrared heating elements, such as tubes, which extend in sections along the transport path of the plastic preforms.

[0047] It can be seen from the small arrows that the plastic preforms are also rotated with respect to their longitudinal axis during transport along the first transport section. Such a rotation of the plastic preforms also takes place in the region of the second transport section. However, in the region of the first transport section 22, a uniform rotation of the plastic preforms takes place, i.e., they are heated uniformly in the circumferential direction, and in the region of the second transport section 24, an uneven rotation preferably takes place, so that the plastic preforms are heated unevenly in a circumferential direction with respect to the longitudinal direction of the plastic preforms. The reference numeral 80 designates a holding device or a spindle, which serves to hold the plastic preforms. The longitudinal direction of the plastic preforms runs in Fig. 1 perpendicular to the figure.

[0048] Fig. Figure 2 shows a more detailed illustration of the deflection area and the alignment area. Roman numerals indicate sections of the alignment process, and Arabic numerals, as usual, indicate components of the device. First, the holding devices 80 exit the first transport section. This is represented by reference symbol I. Reference symbol 26 refers to a rotary drive that serves to rotate the plastic preforms about their longitudinal axis. The plastic preforms are—as explained in more detail below—arranged on spindles (serving as holding devices 80). In the area of ​​section I, this spindle leaves the heating lane and also the rotary drive, which can in particular be a linear drive.

[0049] From this point on, the holding device 80 or the spindle (with the plastic preform arranged thereon) can rotate freely. A guide pin 96 serving as an alignment element (see FIG. Fig. 3). Roller bearings and cam rollers are also provided here. Reference numerals 54, 52, and 56 refer to an alignment device that aligns this alignment element or guide pin 96. As shown in Fig. 2 and Fig. 3, this guide pin 96 is guided over the alignment element 54 with its inclined surface 54a (cf. Fig. 3). This guide element 54 is adjoined on the opposite side by a brush element 52, which further aligns the guide pin 96. This will be explained with reference to Fig. 3 explained in more detail.

[0050] There are two positions B and A in Fig. 3, wherein position A represents a drag position in which the guide pin 96 is already correctly oriented, and reference symbol B represents a position in which the guide pin 96 is still in a forward position and therefore incorrectly oriented. It can be seen that the brush element 52 (cf. Fig. 3) now correctly aligns this guide pin 96 so that it is always in the dragging position. Thus, the alignment element or the guide pin 96 is draggingly aligned via brushes and guide slots depending on the transport chain movement. Reference numeral 56 denotes a further guide element, which forms a guide groove with the alignment element 54, in which the alignment element or the guide pin 96 is precisely aligned. This process is described in Fig. 2 is provided with the reference symbol III. The described pre-alignment by the brush element 52 is provided with the reference symbol II. The alignment element or the guide pin 96 is arranged on an alignment body (also referred to as orientation body 92) (cf. Fig. 4 and Fig. 5).

[0051] Once the guide pin 96 is aligned, and thus also the orientation body 92 and, with it, the holding device 80 or the spindle on which the plastic preform is arranged, the plastic preform, along with the holding element, enters the actual deflection area. In this deflection area, a transport wheel 62 or deflection wheel is provided, which has a plurality of recesses 64 into which parts of the holding device can engage.

[0052] In this area, a plurality of rotary drives 42 or motors, such as servo and stepper motors, are attached to the transport wheel 62 (see Fig. 4, Fig. 5). This beginning of the deflection area is designated by reference numeral IV. More precisely, servo or stepper motors rotating with the deflection wheel 62 are mounted above the deflection wheel 62. Reference numeral 64, as mentioned above, designates recesses in the deflection wheel for partially accommodating chain links. These rotary drives or motors 42 can be adjusted vertically—as explained in more detail below—with this stroke preferably being controlled via a cam or also being achieved via a linear drive (rotary-lift motor).

[0053] Reference numeral 74 refers to a driver device, such as a driver bell, which is arranged on the rotary drive 42 and which serves to transmit the rotary movement of the rotary drive 42 to the orientation body 92. For this purpose, the alignment element 96 arranged on the orientation body 92 can engage in a recess 98 of the driver device. It is possible for the driver device to be spring-loaded (not shown), i.e., prestressed by a spring relative to the rotary drive 42. This can prevent damage to components or the machine (for example, in the event of a sensor failure).

[0054] The reference number 12 (cf. Fig. 2) refers to a position detection device which detects a rotational position of the plastic preforms or the threads (Section VI). In Section V, the individual drive devices are described in more detail with reference to Fig. 4 and Fig. 5 explained, coupled into the holding mandrels.

[0055] The position detection device or camera system detects the position, in particular of a thread or a mouthpiece marking, on the plastic preform and transmits this information to the control of the individual rotary drives or stepper motors 42, which can then rotate the plastic preforms and / or the orientation bodies 92. In step VII, the difference angle between the position of the guide pin and the mouthpiece marking can be determined via a software calculation. The motor then rotates the guide pin of the spindle to the correct position relative to the mouthpiece marking. These processes take place in sections VI and VII.

[0056] In section VIII, the coupling is re-engaged, and the guide pin 96 and the spindle shaft or retaining element 84 form a firmly connected unit. In this position, however, the position of the guide pin is aligned with a specific mark on the preform.

[0057] In Section IX (cf. Fig. 2) A further position calculation can now be performed to determine the actual angular position relative to a reference position. It is important to ensure that the guide pins 96 of the spindles are realigned to a defined drag position, since during this phase the guide pins 96 can be in any desired state depending on the initial position of the mouthpiece marking.

[0058] Finally, in Section X (cf. Fig. 2) is disengaged, and the motor unit or the drive bell lifts off, and the guide pin is transferred to another guide groove. Finally, the guide groove and thus also the plastic preform are transferred in the correct alignment to the second heating section 24 (section XI), where they are then subjected to a heating profile in the circumferential direction, particularly according to user specifications (step XII). Please note that the guide pin is now adjusted to the position of the thread of the plastic preform.

[0059] Fig. Figure 4 illustrates a coupling mechanism. Two coupling parts 92 and 93 are provided, whereby the coupling part 92 can be connected to the rotary drive 42 (via engagement of the bolt 96 in the recess 98). This coupling part 92 is also the orientation body 92, but it would also be conceivable for these elements to be formed separately. This rotary drive 42 is lowered—as illustrated by the arrow—and in this way the guide bolt 96 enters a recess 98, so that the two elements 92 and 94 are coupled together. Fig. 4 shows that the coupling parts 92 are positioned slightly higher in the left and right parts of the figure and are therefore not engaged. Reference numeral 90 refers to the coupling device as a whole. The rotary drive 42 is engaged only in the two right-hand parts of the figure, or offset downward by the stroke y.

[0060] In Fig. 5 shows that only in the middle part of the figure the coupling parts 92 and 93 are coupled. The reference number 40 in the Fig. 4 and Fig. 5 indicates the respective rotating device used for alignment. Therefore, in general, two coupling devices or coupling points are preferably located in the drive train between the rotary drive 42 and the holding element 84, namely, on the one hand, the coupling device 90 and, on the other hand, the connection between the driver device 74 and the orientation body 92. In other words, the orientation body 92 is preferably arranged between two coupling points, so that, by appropriately actuating the two coupling devices, it can be determined whether the rotating device rotates only the orientation body 92 or the orientation body 92 and the holding element 84. In a further advantageous embodiment (not shown), it is conceivable to also realize the coupling stroke via the coupling part 93 via the lifting movement Y of the rotating device 40.Here, the coupling part 93 is not designed as a claw with a circumferential groove, but as a pot whose upper edge protrudes beyond the coupling part 92. Thus, a separate or second stroke control of the coupling (also not shown) can be omitted (clutch stroke X is then part of stroke Y).

[0061] The Fig. 6 and Fig. 7 show representations to illustrate the holding device 80 according to the invention for holding the plastic preforms (not shown), wherein Fig. 6 shows the holding device 80 in its entirety in two different positions of the coupling and Fig. 7 a detailed view of the coupling device 90.

[0062] Reference numeral 84 designates the holding element, which is arranged on a guide body 85, which in turn is rotatably mounted by means of bearings 87 and 104. Reference numeral 86 designates a gearwheel which, during operation, can roll against a rack (not shown), thus generating rotation of the holding element 84 with respect to the longitudinal axis L. The holding element is biased downward by a spring device 88 and can be pulled upward against the spring force of this spring device to remove the plastic preform. Reference numeral 89 designates a support for the holding element 84.

[0063] The reference numeral 77 denotes a further spring device, which urges the holding device into a closed position of the coupling device 90. This closed or engaged position is shown in the right part of Fig. 6 shown.

[0064] Fig. 7 shows two enlarged views of the Fig. 6. This enlarged view also shows a bearing device 95 which rotatably mounts the coupling part 92 with the projection 96 relative to the carrier 89 and thus to the holding element 84, so that when the coupling is open, the projection 96 can be aligned with respect to the holding element 84 and thus with respect to the plastic preform arranged thereon with regard to its rotational position.

[0065] The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided they are novel, individually or in combination, over the prior art. It is further noted that the individual figures also describe features that may be advantageous in and of themselves. The skilled person will immediately recognize that a specific feature described in a figure may be advantageous even without adopting additional features from that figure. Furthermore, the skilled person will recognize that advantages may also arise from a combination of several features shown in individual or different figures. List of reference symbols 1 device 2 Transport device 4 first heating devices 6 Alignment device 8 second heating devices 10 plastic preforms 12 Position detection device 18 Holding element 22 first transport section 24 second transport section / heating section 26 Rotary drive 32 Feed chute 34 single-stroke star 36 transfer stars 40 Rotating device 42 rotary actuators or motors 52 Alignment device / brush element 54 Alignment device / guide element 54a Inclined surface 56 Alignment device / guide element 62 Transport wheel or deflection wheel 64 recess 74 Carrier device 80 Holding device or spindle 82 guide bolts 84 Holding element 87, 104 camps 88 spring element 89 carriers 90 Coupling device 92 Orientation body and coupling part 93 Coupling part 94 Coupling part / element 96 Alignment element or guide bolt 98 recess A Position A B Position B L Longitudinal axis P Transport path I The holding elements run out of the first transport section II Pre-alignment by the brush element III Alignment of the guide pin IV Beginning of the deflection area V Coupling the rotating devices VI Detection of the rotational position of the plastic preform VII Determination of the difference angle VIII Coupling IX further position calculation X Extract XI Transfer of the plastic preform with correct alignment XII Heating with profile

Claims

[1] Device (1) for heating plastic preforms (10) with a transport device (2) which transports the plastic preforms (10) along a predetermined transport path (P), with a first transport section (22) along which at least one first heating device (4) is arranged, which heats the plastic preforms (10) during their transport along the first transport section (22), and with a second transport section (24), along which at least one second heating device (8) is arranged, which heats the plastic preforms (10) during their transport along the second transport section (24), characterized bythat the device (1) has an alignment device (6) which aligns the plastic preforms (10) with regard to a rotational position with respect to their longitudinal axes (L), wherein this alignment device (6) is arranged along the transport path (P) of the plastic preforms (10) between the first transport section (22) and the second transport section (24). [2] Device (1) according to claim 1, characterized by that the alignment device (6) has a carrier (89) rotatable about a predetermined axis of rotation, by means of which the plastic preforms (10) are transported in sections along the transport path (P). [3] Device (1) according to at least one of the preceding claims, characterized by that the device (1) has a rotational position detection device (12) which detects a rotational position of the plastic preforms (10) with respect to their longitudinal axis (L). [4] Device (1) according to claim 1, characterized by that the alignment device (6) has at least one rotating device (40) which is suitable and intended to effect an individual rotation of the plastic preforms (10) with respect to their longitudinal axis (L) while the plastic preforms (10) are transported by the alignment device (6). [5] Device (1) according to claim 4, characterized by that the rotating device (40) has a rotary drive (42) and a switchable coupling device (90) in order to transmit a rotary movement of the rotary drive (42) to holding elements (84) for holding the plastic preforms and / or to an orientation body (92). [6] Device (1) according to claim 5, characterized by that the rotating device (40) has an aligning device (52, 54, 56) for aligning an orientation body (92) which can be coupled to holding elements (84) for holding the plastic preforms (10) in a predetermined rotational position. [7] Device (1) according to at least one of the preceding claims, characterized by that the alignment device has a plurality of motor drives for rotating the plastic preforms (10) with respect to their longitudinal axis (L) and / or for rotating an orientation body (92) with respect to the longitudinal axis (L). [8] Holding device (80) for holding plastic preforms (10) during transport of the plastic preforms through a device for heating the plastic preforms (10), with a holding element (84) which can be inserted into a mouth of the plastic preforms in order to hold them, wherein the holding element (84) is rotatable with respect to a longitudinal axis (L) of the plastic preforms (10), with an orientation body (92) which is rotatable with respect to the longitudinal axis (L) of the plastic preforms (10), wherein the orientation body (92) has an alignment element (96) which enables an alignment of the orientation body (92) with respect to a rotational position with respect to the longitudinal axis (L) of the plastic preforms (10) during a transport movement of the holding device (80) along a predetermined transport path (P), characterized bythat the holding device (80) has a switchable coupling device (90) for coupling a rotational movement of the holding element (84) to a rotational movement of the orientation body (92) and for decoupling a rotational movement of the holding element (84) from a rotational movement of the orientation body (92). [9] Method for heating plastic preforms (10), wherein the plastic preforms (10) are first transported along a first transport section (22) and heated during this transport and then transported along a second transport section (24) and heated during this transport, wherein the plastic preforms (10) are heated unevenly with respect to their circumferential direction at least during their transport along the second transport section (24), characterized bythat the plastic preforms (10) are aligned with respect to a rotational position relative to their longitudinal axis (L) in an alignment section arranged between the first transport section (22) and the second transport section (24). [10] Method according to claim 9, characterized by that a rotational position of the plastic preforms (10) with respect to their longitudinal axis (L) is detected.

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