DE102010022126B4 - Automatic setting of the pitch of a conveyor chain - Google Patents

Abstract

Conveyor chain (14) for transporting articles (30) or containers in the food industry, the conveyor chain (14) consisting of chain links (16), with holding devices (18) for the articles (30) or containers being arranged on chain links (16) which have a defined distance from one another and wherein the distances between the chain links (16) are adjustable, characterized in that the conveyor chain (14) further comprises mechanically adjustable means (20, 40) for changing the distances between the chain links (16), wherein the mechanically adjustable means (20, 40) are each arranged between adjacent chain links (16).

Description

The present invention relates to a conveyor chain, a heating section with a conveyor chain and a method for changing the pitch in a conveyor chain according to the features of the preamble of claims 1, 6 and 12.

State of the art

When producing containers from a thermoplastic material, so-called preforms are used, which are brought into the desired shape by blow molding. The preforms are first thermally conditioned along a transport path in the area of a heating section. This means that the preforms are heated before the subsequent blow molding process is carried out, in which the preforms are formed into the desired container by the action of compressed air.

The preforms come out of the heating section at defined intervals and are generally transferred to the downstream blow molding machine via so-called transfer stars. The distance between the preforms may have to be adjusted prior to stretch blow molding according to the size and distance of the blow molds used.

Currently, for example, depending on the mouth diameter of the largest preforms transported by the customer, either a conveyor chain with a so-called oven chain division with 40 mm or 50 mm spacing between the transported preforms is used in the heating module of the blow molding machine.

It is desirable to use the smallest possible pitch, i.e. the smallest possible distance between the preforms within the heating section, in order to be able to move preforms through the furnace as quickly and space-saving as possible.

The disadvantage of using the small 40 mm pitch is in particular that only preforms with mouthpieces up to a certain size can be processed. If preforms with a larger mouth diameter are to be used, another heating module must be used or the existing heating module must be converted accordingly, which is labor-intensive and results in longer downtimes.

The US script US 7 435 076 B2 generally describes the conditioning of a preform while it is passing through heating and cooling sections. The preforms are arranged on a conveyor chain and pass through certain conditioning stations. The holders for the preforms are coupled to one another at a firmly defined distance via a joint.

DE 39 10 293 C2 discloses a transport device with at least one transport chain which moves the preforms intermittently past radiant heaters to the removal station. The rate of advance of the preforms can be adjusted according to the respective conditions. A holder is releasably attached to each two adjacent chain links of the transport chain, which should be easily dismantled when the transport device is converted for processing larger preforms. With such a conversion, the distance between the holders for the preforms in the transport direction can be changed, so that different diameters of preforms to be heated can be transported and the gaps are minimized during transport through the heating station. In particular, the transport chain can be converted in a simple manual manner in such a way that, using the same brackets, one chain link remains free between adjacent brackets, so that the center points of the brackets can have a distance of 66 mm.

The utility model DE 298 16 128 U1 describes a conveyor chain that can be adjusted in length, each chain link being equipped with a cylindrical bore for rigidly receiving a bolt and with an elongated hole for receiving a bolt in a longitudinally movable manner.

The patent DE 39 10 293 C2 describes this releasable arrangement of brackets on a conveyor chain, so that the distance between adjacent brackets can be changed accordingly by removing individual brackets.

The patent EP 0178324 B1 shows a device with a stationary guide track and a displaceable guide track, in which the distances between the holding devices can be changed.

The disclosure document CH 699597 A1 discloses a conveyor device for conveying and aligning flat products. Here, a distance between the sliding cams serving as a stop can be adjusted without parts of the device having to be replaced.

The object of the invention is to allow a simple adjustment of the distances between holders for articles on a conveyor chain, in order to easily adapt the conveyor chain to the given requirements, with preferably no manual retooling being necessary.

The above object is achieved by a device, a heating section and a method which include the features in claims 1, 6 and 12. Further advantageous refinements are described by the subclaims.

description

The invention relates to a conveyor chain for articles. Such a conveyor chain can be used, for example, to transport any article from a first processing device to a second processing device. Such a conveyor chain is used to transport articles or containers, in particular preforms or finished bottles in the food industry, in particular in the manufacture of containers for packaging beverages. Such a conveyor chain is preferably used to transport preforms through a heating section before they are fed to a blow molding module. Such a chain can also be used to provide preforms or finished bottles in a buffer before the drinks are filled. Use in a pasteurizer or the like is also conceivable.

A conveyor chain consists of chain links on which holding devices for the articles are arranged. The holding devices can be arranged on every chain link, on every second chain link, on every third chain link, etc. The holding devices are preferably arranged at regular intervals on the conveyor chain, i.e. the holding devices are at a defined distance from one another. It is provided that the distances between the chain links are adjustable. Because the holding devices do not necessarily have to be arranged on each chain link, but rather an arrangement on every second chain link or the like is also possible, the distances between the holding devices can also be easily adjusted or changed.

According to the invention, the conveyor chain has mechanically adjustable means for changing the distances between the holding devices, which are arranged between the chain links or the holding devices. It is provided that the mechanically adjustable means are each arranged between adjacent chain links. In particular, no holding devices are arranged on the means for changing the distances. In particular, the mechanically adjustable means for changing the distances are concurrently.

The change in the distances - this is also referred to as division - is particularly necessary in order to adapt the conveyor chain to different sizes of the transported articles. If, for example, preforms are conveyed through a heating section, then it is necessary to adapt the distances between the chain links or the holding devices to the largest diameter of the preforms used. The shape and size of the preforms depends on which containers are to be made from them. In particular, the size and wall thickness of the containers to be produced play a role.

According to a preferred embodiment, the means for changing the distances between the chain links or the holding devices are control cams which can be changed in their arrangement or orientation and, due to their shape, result in the distance between the adjacent chain links being changed. The arrangement of the control cams can be changed by means of a drive device, for example a cylinder or an electric motor (servo), an adjustable control cam or the like.

In particular, they are designed to be rotatable control cams and have a guide element which can engage in the control cam and extend within it so that its position can be changed. The position of the guide element correlates directly with the spatial arrangement of the control cam via a swivel joint. For example, the guide element can have a first working position in which the control cam is arranged between the chain links in a space-saving manner, so that the minimum possible pitch is set. If a larger pitch is required, the control cam is advanced and the guide element in the control cam is brought into a corresponding second working position. By rotating the control cam around the swivel joint, it now creates the maximum possible distance between the two chain links. Furthermore, intermediate positions are of course possible, which make it possible to variably adjust the pitch between the maximum and the minimum possible.

A spring element, for example a tension spring, can be arranged between the chain links in order to support the adjustment of the pitch. Spring elements can also be dispensed with if the control cams are arranged in a forced guidance, for example in a link or groove, on the chain links. Instead of the control cam, the mechanically adjustable means for changing the distances can also be at least one stationary screw. In particular, this does not attack the preforms, but rather the chain links or transport trolleys.

The preform to be transported has a support ring below an opening area and is supported in this area by the Chain link of the conveyor chain attached holding means held. The mouth area has a thread that must not heat up too much when heated in the heating section so that it does not deform in the subsequent blow molding process. For this reason, the mouth area must be protected from excessive radiation. For this reason, so-called shielding plates (see above) are arranged between the chain links, which protect the holders and / or the mouth area of the preforms from the radiant heat.

The shielding plates represent in particular panels with a square circumference and essentially consist of a flat piece of sheet metal with a thickness of several millimeters or a profiled molded part or the like. They have a central bore which is arranged concentrically to the holding mandrel for the preform . The shielding plate is arranged at the point of separation between the area of the preforms that is to be deformed and that not to be deformed. The adjustment of the distances between the shielding plates is preferably coupled with the adjustment of the holding device, in particular if the shielding plates are arranged fixedly opposite the holding devices. The shielding plates are attached directly to the trolleys for the preforms. In this case, the control cam causes both the change in the spacing of the holding devices and automatically the change in the spacing of the shielding plates. The extendable or elastic elements serve to shield the gaps between the holding elements caused by the increase in the distances.

The adjustment of all distances between all chain links of a conveyor chain is preferably carried out simultaneously and in a coordinated manner; in particular, all adjustment means are controlled and moved together. According to an alternative embodiment, the adjustment of the various adjustment means takes place step by step.

According to a further preferred embodiment, the means for changing the distances between the chain links or holding devices of the conveyor chain are at least one extendable or elastic element that is integrated between two shielding plates.

According to this alternative embodiment, the pull-out and / or elastic element is arranged between two adjacent shielding plates that by adjustment
of the extendable and / or elastic element, the distance between the adjacent chain links and thus the distance between the adjacent holding means is changed.

The extendable and / or elastic element is arranged in particular between two adjacent shielding plates in such a way that by adjusting the extendable and / or elastic element, the opening area of the preforms continues to be optimally sealed off from the heat radiation. The element consists in particular of the same material as the shielding plate. In particular, it is a reflective material such as stainless steel or aluminum.

In a first working position, the extendable and / or elastic element is, for example, in the retracted state, so that the distance between the chain links is only determined by the size of the shielding plates. This corresponds to the minimum division. By moving the shielding plates along the extendable and / or elastic element, the distance between the chain links of the conveyor chain can be set as desired up to a maximum pitch in a second working position.

According to a further embodiment, the adjustment of the shielding plates takes place with the aid of so-called spacer elements, which serve to adjust the extendable or elastic elements accordingly. The spacing elements can preferably be moved in an automated manner.

The invention further comprises a heating section for heating preforms for processing in a stretch blow molding device. The heating section has at least one transport means for moving the preforms along a transport section. The at least one transport means comprises a conveyor chain which consists of chain links and which has the properties already described.

By changing the pitch between the chain links or the holding means, the length of the conveyor chain changes. The processing device, for example the heating section, must therefore be able to be adapted to the changed length of the conveyor chain.

According to one embodiment, the length of the heating path is changed. In particular, it is possible to pull the heating section apart or to push it together. According to a further embodiment, the heating section comprises a changeover section, the length of which is adjustable / changeable and via which the length of the conveyor chain can be changed. According to an alternative embodiment, the length of the changeover section is fixed.

The heating device used must be used so that the preforms are nevertheless heated over the entire length of the heating section may also be adjusted if necessary. If heating pockets are used in which a heating pocket with radiation elements, in particular IR radiators, is assigned to each preform, then this is not a problem since each preform is thus assigned its own heating device.

According to one embodiment of the invention, the heating pockets used can be adapted to the size of the preforms transported / to which heat is to be applied. This is advantageous because the absorption of the heat given off by the radiators depends on the distance between the radiator and the preform. It is therefore advantageous if, in the case of preforms with a small diameter, the heating pockets also have a smaller diameter, so that the radiation elements are arranged closer to the preform to be heated and thus a lower radiation output is necessary for the heating.

A heating pocket can be understood to mean a chamber that completely surrounds the preform with radiant heaters arranged thereon or a microwave resonator.

Since the heating pockets are also arranged on the conveyor chain, a conveyor chain with a smaller pitch can be used for smaller preforms and smaller heating pockets. In this case the links of the conveyor chain can be the heating bags themselves. Mechanically adjustable means can then be dispensed with and the distance can be changed by the drive means which are individually assigned to each heating pocket. Drive means can be, for example, linear motors (rotors) that are mounted on a stator on the heating wheel, stationary control cams, servomotors or the like mounted on the axis of rotation.

For example, the heating pockets have movable walls with radiation elements, the walls being connected via hinged hinges or the like, and walls can be added to match the diameter of the preforms. If the heating pockets have cylindrical chambers with radiation elements instead of folding walls, it can also be provided that these can be adapted to the diameter of the preforms in order to achieve optimal utilization of the radiation heat. A cylindrical chamber consists of a windable sheet metal that can be wound and unwound by means of its own drive and thus changed in diameter. Adjacent cylindrical chambers are arranged in particular with a slight height offset from one another in order to avoid overlapping of the non-adaptable metal sheets (bottom and top) when the distance between the adjacent cylindrical chambers changes.

If, on the other hand, heating boxes with radiant elements are used to heat the preforms, which are arranged along linear areas of the conveyor chain, then under certain circumstances there may be too many heating boxes with a shortened conveyor path, so that unnecessary energy would be consumed. For this reason, the heating boxes can preferably be switched off and / or removed from the effective area of the heating section. This can be done, for example, by pushing out or folding away the heating boxes, the heating boxes can also be removed from the effective area of the heating section by means of a lifting device, etc. This is particularly advantageous because this reduces the space required for the heating section in a filling line can. This means that the same heating section can be used for different applications or filling lines.

Furthermore, a heating section generally comprises a chain for generating the rotation of the preforms so that they are heated uniformly around their entire circumference. This chain, too, must be adapted to the length of the heating section and its length can therefore preferably be changed.

The invention further comprises a method for changing the pitch of a conveyor chain, the conveyor chain being used in a heating section for heating preforms for processing in a stretch blow molding device. The conveyor chain has the properties described above. During the process, the length of the conveyor chain changes and the heating section is automatically adapted to the length of the conveyor chain. Here, the spacing of the holding means is adjusted by adjusting the spacing between adjacent chain links.

Furthermore, a change in the division according to the invention can be used if, for example, less is to be produced in a filling line. Here it is not always easy to reduce the throughput, since with some machines it is not mechanically possible to simply reduce the machine output. For example, the belt pretension in the gearbox to the transfer star and blowing wheel only allows a certain range in the output rate (bottles per hour). A lower throughput cannot be achieved, since otherwise the transfer points of the preforms to the blow wheel are no longer correct.

For example, an adaptation to this problem is conventionally done in that only every second heating mandrel is equipped and thus only to every second transfer arm of the transfer star or to every second blow mold of the Blow molding module is passed. The major disadvantage here is that the unequipped heating mandrels have to be protected with a shielding element, since otherwise the rubber-sprung mounting of the gripping jaws will be damaged.

To solve this problem, the invention therefore also comprises a method for adapting the distances between holding means for articles on a conveyor chain in a first processing device to the distances between holding means for articles on a transfer device or in a second processing device. A conveyor chain described above is used in the first processing device. The distances between the holding means on the conveyor chain are set so that the articles are only transferred to every second holding means of the transfer device or the second processing device.

So every heating mandrel can be equipped on the conveyor chain of a heating section. However, there is only one transfer to every second transfer arm or every second blow mold.

If the conveyor chain is used in a heating section, the holding device for the articles can be a so-called heating mandrel. Such a heating mandrel preferably comprises at least two, particularly preferably at least three or at least five movable legs. Each leg consists of a movable lower leg part and a movable upper leg part. The upper and lower leg parts are preferably movably connected to one another via a first connecting element. The first connection element is preferably a rotatable hinge or some other connection element that can produce a movable connection between the two leg parts. Furthermore, the at least two legs are in operative connection at their upper end via a second connecting element with a spring element. This enables a frictional connection between the movable lower leg parts and the engagement area of the article to be transported. If the transported article is a preform, for example a frictional connection is established between the movable lower leg parts and the mouth area of the preform. This holding device allows a very large range of processable diameters of the articles to be transported, so that it is not necessary to change the heating mandrels when switching to preforms with a different opening diameter.

The heating mandrel in particular represents an invention that can be claimed independently, which can not only be used in a conveyor chain or heating section according to the invention, but can also be used in other devices for the secure holding of articles. Instead of this mandrel, quick-change mandrels could also be used in the heating section, such as those from DE 10 2007 037 400 A1 are known. It would also be conceivable to use a quick-change machine for the heating mandrels or shielding plates.

Figure list

• 1 und 2 zeigen einen schematischen Aufbau einer ersten Ausführungsform einer mechanischen Verstelleinheit.
• 3 bis 6 zeigen einen schematischen Aufbau einer zweiten Ausführungsform einer mechanischen Verstelleinheit.
• 7 bis 9 zeigen eine Möglichkeit zur Verstellung der zweiten Ausführungsform.
• 10 bis 12 zeigen einen schematischen Aufbau einer dritten Ausführungsform.
• 13 bis 20 zeigen Möglichkeiten zur Anpassung einer Heizstrecke an die veränderte Länge der Förderkette.
• 21 und 22 zeigen die Anpassung einer Heiztasche an die Größe des behandelten Vorformlings.
• 23 zeigt eine Halterung für Vorformlinge.

In the following, exemplary embodiments are intended to explain the invention and its advantages in more detail with reference to the accompanying figures. The proportions of the individual elements to one another in the figures do not always correspond to the real proportions, since some forms are simplified and other forms are shown enlarged in relation to other elements for better illustration.

• 1 and 2 show a schematic structure of a first embodiment of a mechanical adjustment unit.
• 3 to 6th show a schematic structure of a second embodiment of a mechanical adjustment unit.
• 7th to 9 show a way of adjusting the second embodiment.
• 10 to 12th show a schematic structure of a third embodiment.
• 13th to 20th show options for adapting a heating section to the changed length of the conveyor chain.
• 21 and 22nd show the adaptation of a heating pocket to the size of the preform being treated.
• 23 shows a holder for preforms.

Identical reference symbols are used for identical or identically acting elements of the invention. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures which are necessary for the description of the respective figure. The illustrated embodiments merely represent examples of how the device according to the invention or the method according to the invention can be designed and do not represent a final limitation.

1 and 2 show a schematic structure of a first embodiment of a mechanical adjustment unit 10 .

In a transport chain 14th there are trolleys 16 for the articles to be transported. The transport trolleys 16 have holding devices 18th for holding the articles to be transported and shielding plates for shielding the to transporting article (not shown, cf. 3 ) on. Will be with the transport chain 14th For example, preforms are transported through a heating section, the holding devices can be so-called holding or heating mandrels, for example.

Between two transport trolleys 16 are each an adjustment unit 10 and a tension spring 12th arranged. The adjustment unit 10 consists of an oval or ellipsoidal cam 20th that has one of a cylinder 23 deliverable curve 24 is operated. By pivoting the cam 20th an angle of largely 90 ° can be set between a minimum pitch ( 1 ) and a maximum division ( 2 ) can be switched. Any intermediate distance can be set by means of appropriate intermediate positions.

Pivoting the cams 20th is via a guide element 21 achieved that in the control curve 24 engages and is adjustable by this. The position of the guide element 21 within the control curve 24 correlated via a swivel joint 22nd directly with the spatial arrangement of the control cam 20th .

In 1 is the adjustment unit 10 in a first working position AS1 shown. Here is the control cam 20th space-saving between the chain links 16 is arranged so that the minimum possible pitch is set. If a larger pitch is required, the control cam is used 24 delivered and the guide element 21 via the control cam 24 in a corresponding second working position AS2 brought. By turning the control cam 20th around the swivel joint 22nd this now creates the maximum possible distance between the two chain links 16 . It is also possible to set the control cam in intermediate positions 20th which make it possible to vary the pitch.

The spring element arranged between the chain links 12th is used to make it easier to set the pitch.

Furthermore, a stop (not shown) for the control cam 20th on the trolley 16 or the transport chain 14th be provided that a rotation of the control cam 20th until stops shortly after a dead center has passed. In this way, it is possible to ensure a defined distance. The stop can also be adjustable for intermediate positions.

3 to 6th each show a schematic structure of a second embodiment 10 . This is an extendable or elastic element 40 used that is integrated between two shielding plates 42a, 42b.

The preform to be transported 30th points below a mouth area 32 a support ring 34 and is in the area of the support ring 34 by the holding means 18th of the transport trolley 16 (not shown, cf. 1 ) held. The mouth area 32 has a support ring 34 and an overlying thread 36 on, which is when the preform is heated 30th must not heat up too much in the heating section so that they do not deform in the subsequent blow molding process. For this reason, the mouth area 32 be protected from excessive radiation. Therefore are on the chain links with the transport trolleys 16 (not shown, cf. 1 ) Shielding plates 42 arranged, which prevent penetration of the heating radiation between the preforms or the holding mandrels to a plane in which the mouth areas are transported. According to the embodiment shown here, an extendable and / or elastic element is located between the shielding plate 42a of a first transport carriage 16a and the shielding plate 42b of a second transport carriage 16b 40 for shielding the distance between two shielding plates 42a, 42b when the distance between two transport trolleys 16a, 16b is increased.

3 and 5 each show a first working position AS1 , in which the distance between the shielding plates 42a, 42b of adjacent transport carriages 16a, 16b (not shown) or holding devices 18a, 18b is minimized. This is for articles, especially preforms 30th with a small diameter, advantageous in order to produce the closest possible arrangement. If a greater distance is required between the transported articles, the shielding plates 42a, 42b of adjacent transport carriages 16a, 16b (not shown) or holding devices 18a, 18b are held by the control cam 20th distanced from each other.

The 3 to 6th represent a variant in which the shielding plates 42a, 42b next to the holding pins (not shown) are firmly held on the trolleys 16a, 16b and, so to speak, can be adjusted or pulled apart via this connection together with the holding pins.

It would also be conceivable that the shielding plates 42a, 42b are not permanently attached to the transport trolleys 16a, 16b and have to be adjusted separately. For this purpose, the shielding plates 42a, 42b can be provided by the elastic element arranged between them 40 are actively distanced from one another, so to speak, by the shielding plates 42a, 42b - as in FIG 7th to 9 shown - for example along the elastic adjustment element 40 be moved.

A possible mechanism for adjustment is in the 7th to 9 shown. Here are the extendable adjustment element 40 so-called spacer elements 44 assigned, which can be moved apart and together, whereby the distance between the shielding plates 42a, 42b and / or the transported preforms 30th or the retaining pins (not shown) changed. The spacer elements 44 are preferably controlled and operated together as required. If the shielding plates 42a, 42b are firmly connected to the transport carriages 16a, 16b, the control cams (not shown) could also be dispensed with by removing the spacing elements 44 used for adjustment.

It would also be conceivable that the shielding is carried out by two rails that are arranged in a stationary manner on the heating section and are also at the level of the support ring 34 of the preform 30th is located. In this case, the intermediate areas (“gaps”) are not shielded, which is not so cheap, but is possible in certain applications.

10 to 12th show an embodiment in which the extendable adjustment element 40 is shaped so that it also shields the set when retracted. In particular, this embodiment shows that in the retracted state of the adjusting element 40 only preforms 30k with a small diameter can be conveyed ( 11 ). If, on the other hand, there is the adjusting element 40 in the extended state, then preforms 30g with a larger diameter can be conveyed ( 12th ). In this case, the extendable adjusting element is provided with at least one semicircular bulge for the preforms 30g and 30k.

Adjusting the furnace pitch changes the length of the open chain. The furnace must be adapted accordingly. There are various ways of doing this, which are described in the 13th to 20th are shown by way of example.

13th and 14th show a heating section that can be changed in length 1 with heating boxes 3 where the heating section 1 to the corresponding length of the furnace chain 2 can be customized. The preforms to be heated run over an inlet star 4th in the heating section 1 one and be over a chain of ovens 2 on heating boxes 3 transported along with IR emitters and / or reflectors. The preforms are preferably rotated about their own longitudinal axis in order to ensure uniform heating. This is preferably done with the help of at least one chain 6th , which causes a rotation of the heating mandrels on which the preforms are held.

In order to only generate the heating energy that is really necessary, it can be provided that only the IR radiators are in the required heating boxes 3 are switched on while the heaters are in the heating boxes that are not required 3nn are turned off. Alternatively it can be provided that the heating boxes 3nn and the reflectors and / or the machine protection (not shown) are designed to be foldable and are only folded for this purpose when required.

A drive (not shown) is used to extend the chain 2 the pulley 2U the furnace or transport chain 2 movable to compensate for the chain extension. The part of the chain which is in engagement with the retaining spikes (not shown) 6th To generate the rotation of the heating mandrels, pulleys can be used here 6U with a drive, not shown, for moving the pulleys 6U be extended or shortened.

15th and 16 each show a further variant of a furnace 1 , which is designed to be pulled apart, with the adjustment of the length of the furnace chain 2 or transport chain 14th via a changeover route 7th ( 15th ) or a siding 7A ( 16 ) he follows. In 15th can the transport chain 14th or the furnace chain 2 , analogous to the chain 6th to generate the rotation of the heating mandrels (cf. 14th ), by moving two or three guide wheels 7U can be extended (dashed lines). A process of a deflection wheel and the inlet star (full lines) would also be conceivable. In the changeover route 7th in particular, there are no preforms for heating. If necessary, can from the siding 7A in 16 to extend the furnace chain 2 also additional heating mandrels 8th or transport trolleys or chain links 16 are retracted to hold the preforms. It is particularly advantageous here if there are no mechanical connections such as springs between the transport trolleys. However, it would also be conceivable that this would be via a drive (not shown) on the furnace chain 2 be attached. Drives (not shown here) for engaging and disengaging the heating mandrels can also be used 8th or transport trolleys or chain links 16 for holding the preforms on or off the furnace chain 2 be provided. As a drive for the advance of the heating mandrels 8th through the oven 1 In particular, a screw (not shown) can also be used.

17th describes a further alternative by means of which the distance between the preforms removed from the heating section can be adapted to the requirements of the downstream processing device. If there is a division delay at the end of the heating section, for example due to an additional acceleration of the preforms in the end area, it is not necessary to perform the necessary division with the aid of a transfer outlet star 5 to manufacture. Instead, it can be handed over to the downstream processing device a transfer star 9 with constant pitch can be used. In particular, the distance between the preforms after or shortly before leaving the linear region at the end of the heating section 1 enlarged. The distance between the preforms is preferably after nine tenths of the heating distance 1 enlarged. The distance between the holding pins 8th is reduced again after the preform has been released and before a new preform is picked up. Alternatively, a screw can also be used to set the distance 88 be used. In particular, this comprises at least one groove which increases at a distance in the longitudinal axis and which engages with the holding mandrels 8th or trolley is to increase their distance by rotating about their longitudinal axis.

The ones in the 13th to 17th The options shown for changing the heating sections can also be used with rotary furnaces. The individual transport trolleys or chain links for holding the preforms would correspond in particular to the individual cavities such as resonators or heating pockets. It should also be noted that the 13th to 17th illustrated furnace chain 2 especially a transport chain 14th as previously described, can represent.

18th manufactures a rotary furnace 1R in which the preforms are heated either with the aid of microwaves in resonators or in individual heating pockets. In this case, the preforms are delayed in division shortly before they are transferred by an outlet star 5 to a blower wheel BR . The division delay is carried out, so to speak, in the rotary furnace. The heating bags 60 and thorns 8th (see. 21 and 22nd ) or cylindrical chambers 75 can be cam-controlled through the furnace 1R to run. In particular, levers can also be used for cornering 87 that turn in a separate curve along the perimeter of the furnace 1R run, are used, which control the distances between the individual cavities of the rotary kiln. For the sake of clarity, there is only one lever here 87 shown for one cavity.

19th and 20th represent a variant of a rotary furnace 1R with heating cavities 60 and with a siding analogous to those in the 15th and 16 shown variants of a heating section 1 represent.

21 and 22nd represent the possibility of a heating pocket / heating cavity 60 to adapt to different diameters of preforms 30k, 30g. The preforms 30g, 30k are in the heating pocket 60 each via a heating mandrel 8th held.

The required diameter of the heating pocket 60 depends in particular on the diameter of the preform 30k, 30g in the area of the support ring 34k, 34g. The preforms 30k, 30g are placed in the heating pocket 60k, 60g by means of radiant heaters 70 warmed up. Switching from a heating pocket 60k for preforms 30k with a small / small diameter ( 21 ) to a heating pocket 60g for preforms 30g with a large diameter ( 22nd ) is done, for example, by delivering two walls 64 with radiant heaters 70 . This is preferably done using a hinge 62 . The advantage of adjusting the heating bag 60 to the diameter of the preform 30th is in particular that the distance between the radiant heater 70 from the preform 30th is thereby minimized, whereby the heat input is improved, so that the radiators can be operated with a lower power, which has a positive effect on the energy balance. The adjustment of the heating bag 60 can be carried out either manually or by means of an adjustable curve.

23 provides a heating mandrel 80 with an additional suspension 82 for secure holding of the preforms 30th in an oven 1 , 1R (see. 13th to 19th ) or in a heated bag 60 represents. The heating mandrel 80 includes in particular movable legs 84 that are in the mouth area 32 of the preform 30th intervention. The thigh 84 are preferably made of a lower part 84a and an upper part 84b constructed, with the lower part 84a and the upper part 84b each leg via a hinge 85 are movably connected to each other. The two legs 84 are in turn at their uppermost point of the upper legs 84b with each other and with a feather 82 via a second hinge 86 movably connected. By moving the spring up and down 82 can lower thighs 84a be adjusted so that they are frictionally engaged in the mouth area 32 of the preform 30th intervention. With such a heating mandrel 80 there can be greater differences in the mouth diameter of different preforms 30th be compensated.

The invention has been described with reference to a preferred embodiment. However, it is conceivable for a person skilled in the art that modifications or changes can be made to the invention without departing from the scope of protection of the claims below.

In particular, a conveyor chain or heating section according to the invention can also be used to transport preforms with a recessed annular groove instead of a support ring or differently designed preforms or containers.

List of reference symbols

1

Oven / heating section

1R

Rotary furnace

2

Furnace chain

2U

Deflection wheel

3

Heating box

3nn

Heating box not required

4th

Inlet star

5

Outlet star

6th

Chain to generate the rotation of the heating mandrels

6U

Deflection wheel

7th

Changeover route

7A

siding

7U

Deflection wheel

8th

Heating mandrel

9

Handover star

10

Adjustment unit

12th

Tension spring

14th

Transport chain

16

Transport trolley

16a / b

Transport trolley

18th

Holding device

18a / b

Holding device

20th

Cam

21st

Guide element

22nd

Swivel joint

23

cylinder

24

Deliverable curve

30th

Preform

30g / k

Large / small preform

32

Mouth area

34

Support ring

36

thread

40

extendable / elastic element

42

Shielding plate

42a / b

Shielding plate

44

Spacer element

60

Heating pocket / heating cavity

60g / k

Heating bag large / small

62

hinge

64

walls

70

Radiant heater

75

cylindrical chamber

80

Heating mandrel

82

feather

84

movable thigh

84a

lower part of the movable leg

84b

upper part of the movable leg

85

hinge

86

hinge

87

lever

88

slug

AS1

first working position

AS2

second working position

BR

Blow wheel

Claims (13)

Conveyor chain (14) for transporting articles (30) or containers in the food industry, the conveyor chain (14) consisting of chain links (16), with holding devices (18) for the articles (30) or containers being arranged on chain links (16) which have a defined distance from one another and wherein the distances between the chain links (16) are adjustable, characterized in that the conveyor chain (14) further comprises mechanically adjustable means (20, 40) for changing the distances between the chain links (16), wherein the mechanically adjustable means (20, 40) are each arranged between adjacent chain links (16). Conveyor chain (14) after Claim 1 wherein the means for changing the distances between the chain links (16) comprise control cams (20) and adjustable curves (24). Conveyor chain (14) after Claim 1 wherein the means for changing the distances between the chain links (16) comprise at least one extensible or elastic element (40). Conveyor chain (14) after Claim 3 wherein the means for changing the distances between the chain links (16) comprise spacer elements (44). Conveyor chain (14) according to one of the preceding claims, wherein the holding device (18) for the articles (30) is a heating mandrel (8, 80), the comprises at least two movable legs (84), each leg (84) consisting of a lower leg part (84a) and an upper leg part (84b) which are movably connected to one another via a first connecting element (85) and wherein the legs (84) are in operative connection with a spring element (82) at their upper end of the upper leg parts (84b) via a second connecting element (86). Heating section (1, 1R) for heating preforms (30) for processing in a stretch blow molding device (BR), the heating section (1, 1R) having at least one transport means for moving the preforms (30) along a transport section, the at least one Transport means comprises a conveyor chain (14) which consists of chain links (16), with holding devices (18) for the articles (30) being arranged on chain links (16) which are at a defined distance from one another and wherein the distances between the chain links (16 ) are adjustable, characterized in that the conveyor chain (14) further comprises mechanically adjustable means (20, 40) for changing the distances between the chain links (16), the mechanically adjustable means (20, 40) each between adjacent chain links (16) ) are arranged. Heating section (1, 1R) Claim 6 , wherein the length of the heating section (1, 1R) can be changed. Heating section (1, 1R) after one of the Claims 6 to 7th , wherein the heating section (1, 1R) comprises a changeover section (7). Heating section (1, 1R) after one of the Claims 6 to 8th , wherein the heating section (1, 1R) comprises heating boxes (3) with radiation elements for heating the preforms (30), which can be switched off and / or brought out of the effective area of the heating section (1, 1R) and / or wherein the heating section (1, 1R) comprises a chain (6) for generating the rotation of the preforms (30), the length of which is variable. Heating section (1, 1R) after one of the Claims 6 to 8th , wherein the heating section (1, 1R) comprises heating pockets (60) for heating preforms (30), the diameter of which is variable, in particular adaptable to the diameter of the preforms (30, 30g, 30k). Heating section (1, 1R) after one of the Claims 6 to 10 , wherein the holding devices (18) for articles (30g, 30k) with different diameters are adjustable. Method for changing the pitch of a conveyor chain (14), wherein the conveyor chain (14) is used in a heating section (1, 1R) for heating preforms (30) for processing in a stretch blow molding device (BR) and wherein the conveyor chain (14) is the Features of the Claim 1 characterized in that the length of the conveyor chain (14) is changed and that the length of the heating section (1, 1R) is automatically adapted to the length of the conveyor chain (14). Method for adapting the distances between holding means (18) for articles (30) on a conveyor chain (14) in a first processing device (1) to the distances between holding means for articles on a transfer device (5) or in a second processing device (BR), wherein a conveyor chain (14) for transporting articles (30) or containers in the food industry according to one of the Claims 1 to 5 is used, characterized in that the distances between the holding means (18) on the conveyor chain (14) are set so that the articles (30) are transferred to every second holding means (18) of the transfer device (5) or the second processing device (BR) the spacing of the holding means (18) is adjusted by adjusting the spacing between adjacent chain links (16).

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