Rotary device for the transport of articles

A rotary device (10), especially a transfer star, for the transport of articles (15) from a first processing device (1) to a second processing device (5). The rotary device (10) includes a plurality of gripping devices (60) for gripping and holding of articles (15) that are preferably electronically controlled. The distance between the articles (15) in the first processing device (1), e.g. in a heating unit, is different from the distance between the articles (15) in the second processing device (5), e.g. a blow molding device. An electronic control device (30) is located on top of the rotary device (10). This control device (30) controls the distance between the articles (15) fed into the second processing device (5). A method is also provided.

This claims the benefit of German Patent Application DE 10 2010 020 724, filed May 17, 2010 and hereby incorporated by reference herein.

The present invention relates to a rotary device and a method for the transport of articles from a first processing device to a second processing device, whereby the distance between articles in the first processing device is different from the distance between articles in the second processing device and whereby the device comprises a plurality of gripping devices for gripping and holding the articles. The gripping devices are electronically controlled.

BACKGROUND

Preforms are blow molded to produce containers out of a thermoplastic material in a desired shape. The preforms are first thermally conditioned along a transport route in a heating unit. Particularly the preforms are first heated before the subsequent blow molding process is performed. During the blow molding process the preforms are transformed into containers of the desired shape by compressed air.

The distance between the preforms coming out of the heating unit is usually quite small. The preforms are then usually handed over to the subsequently arranged blow molding device by a transfer star or a delivery star. The distance between the preforms has to be enlarged before the blow molding process according to the size and distance of the blow molds.

This is usually done by moving the preform holding clamps in a radial and tangential direction away from each other.

Document WO 2006/050935 discloses a method and a device for the transport of containers that comprise a carrying ring or something alike. Hereby the radial control of the gripping elements is done by a hydraulic or pneumatic device.

DE 10 2006 023 531 A 1 shows a device for the transport of piece goods with a rotary carrier device and a plurality of transport arms, which are swivel mounted on the carrier device. The movement of the at least one carrier arm is independently controlled from the movement of another transport arm.

WO 1998 022374 A1 shows a servo driven, computer controlled transfer system for containers. The system replaces known transfer stars and is able to transport a plurality of containers with different sizes. Because of the servo driven gripping mechanism and the control by a computer this is a so called “intelligent” system. The gripping arms are moved by servo motors, allowing a secure grip of the containers.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a space efficient transfer device whereby the distances between the transported articles can be adjusted easily.

The present invention provides a rotary device, especially a transfer star, for the transport of articles from a first processing device to a second processing device. Such a transfer star can be used for the transport of preforms from a heating unit to a blow molding device, where the preforms are transformed into the containers.

The rotary device comprises a plurality of gripping devices for gripping and holding the articles. The gripping devices grasp the articles in a certain section. The gripping devices can be gripping clamps, gripping claws or something alike, that grab the articles, for instance preforms or bottles, especially in their neck region, preferably below a carrying ring. The gripping devices are preferably electronically controlled.

The distance between the articles in the first processing device, e.g. in a heating unit, is different from the distance between the articles in the second processing device, e.g. a blow molding device. Usually the distance between the articles fed into the blow molding device is bigger than the distance between the articles in the heating unit.

According to the present invention an electronic control device is located on top of the rotary device. This control device controls the distance between the articles fed into the second processing device. The control device especially controls servo motors that change the distances between the gripping devices on the rotary device.

According to a preferred embodiment the control device regulates the speed of rotation which is used to run the rotary device.

According to another preferred embodiment at least one rotary distributor is arranged on top of the rotary device. This comprises for instance means for the transmission of electrical signals. These means are preferentially means for wireless signal transmission, e.g. via WLAN. The rotary distributor can furthermore comprise means for power supply. Again these means can be wireless, e.g. via an inductive power transmission. Hereby the electrical energy is transmitted without contacts from a fixed conductor to one or more mobile consumers. The rotary distributor can additionally comprise means for the distribution of gaseous and/or liquid media. This allows for instance the use of sterile air or the like to blow out and thereby sterilize the preforms.

According to a preferred embodiment the control device is splash water protected, so that the device can be cleaned easily.

Because the control device for the regulation of the distances is arranged on top of the rotary device and not within the second processing device—especially a blow molding device—a very compact and space saving design is possible.

The invention furthermore relates to a method for the transfer of articles from a first processing device to a second processing device, whereby the distance between articles in the first processing device is different from the distance between articles in the second processing device. The transfer of the articles is done by a rotary device that comprises a plurality of gripping devices for gripping and holding the articles, whereby the gripping devices are electronically controlled. According to the invention the electronic control of the gripping devices and/or the electronic control of the distance between the articles are done by an electronic control device that is located on top of the rotary device.

According to a preferred embodiment the control device regulates the speed of rotation which is used to run the rotary device.

According to one embodiment pre-heated preforms are removed from a heating unit by a first rotary device. The preforms are then handed over to a blow molding device by the first rotary device. The distances between the preforms are adjusted by the first rotary device during the delivery of the preforms to the blow molding device. The distances between the preforms are especially enlarged.

The preforms are converted into containers, especially into bottles, by the blow molding device. The blow molded containers are removed from the blow molding device by a second rotary device. Preferentially the first and the second rotary device are run with the same speed of rotation.

The control of the rotary device is preferentially connected to the machine control, allowing a simple joint coordination.

DETAILED DESCRIPTION

The same or equivalent elements of the invention are designated by identical reference characters. Furthermore and for the sake of clarity, only the reference characters relevant for describing the respective figure are provided. It should be understood that the detailed description and specific examples of the device and method according to the invention, while indicating preferred embodiments, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

FIG. 1schematically illustrates the arrangement of a transfer star4between two processing devices1,5.

Preforms15are fed into a heating unit1by an infeed star3. IR emitters are arranged in heating alleys to bring the preforms15to the temperature required for the subsequent conversion into containers8in the blow molding device5.

Preforms15are taken out of the heating unit1by a transfer star4and handed over to the blow molding device5. The distance between the preforms15in the heating unit1is usually smaller than the distance between the preforms15in the blow molds6of the blow molding device5. Therefore the distance between the preforms15has to be adjusted, especially enlarged, according to the size and distance of the utilized blow molds6. This is usually done by a control device that is associated with the blow molding device5.

The blow molded containers8are then removed from the blow molding device5by a discharge star7and handed over to further processing devices.

FIG. 2illustrates a first embodiment of a transfer star10with a first rotary distributor20and at least one control device or controller30arranged on top of the transfer star10.

The transfer star10comprises a rotary table50that is movably supported on a table52, and can be rotated for example by a separate drive. The drive may be controlled for example by the controller30. A vertical rotary axis X runs through the center point of the table52. Transfer arms62with gripping devices60are arranged on the rotary table50. The transfer arms are movable on the table52by rollers63and movable on the rotary table50by a bearing54.

The gripping devices60are required for holding the transported articles. According to the embodiment represented in the drawing, preforms15are held and transported. The gripping devices show a desired, non uniform motion sequence that is produced by means of a curved disc or cam64, although use of servomotors66for opening or closing the grippers is also possible.

The control of the transfer arms62is performed by the control device30, whereby each transfer arm62is associated with the control unit30. The control unit30can furthermore control the gripping motion of the gripping arms of the gripping devices60. Especially the control unit30can adjust the width of the gripping arms according to the transported articles; the width of the gripping arms can especially be adjusted according to the diameter of the preforms15.

A first rotary distributor20is arranged on the central rotation axis X. Another electrical (rotary) distributor25for electrical supply of the control device30is also arranged on the central rotation axis X.

The rotary distributor20for example comprises for instance means for power supply. According to a preferred embodiment these means can be transmitted wireless. This is done, for example, via inductive power transmission, whereby the electrical energy is transmitted without contacts from a fixed conductor to one or more mobile consumers.

Alternatively or additionally the rotary distributor20can comprise means for the distribution of gaseous and/or liquid media. This allows for example the use of sterile air or the like to blow out and thereby sterilize the preforms15before the blow molding process.

In the shown embodiment the electrical signals are transmitted from the electrical (rotary) distributor25to the control device30via supply line26. Alternatively the electrical signals can be transmitted wireless.

FIG. 3illustrates a second embodiment of a transfer star10with a first rotary distributor20, a second rotary distributor22and with a control device30arranged on top of the transfer star10. The control device30is splash water protected by a special housing32, so that the device30can be cleaned easily.

This embodiment shows an additional second rotary distributor22that is arranged on top of the first rotary distributor20. Thereby a supply with one or more of the already described means is possible, especially with means for power supply and signal transmission and with means for the distribution of gaseous and/or liquid media.

The invention was especially described in reference to a heating unit1and a blow molding device5for blow molding plastic preforms15into plastic containers8. However it should be noted, that a transfer star10according to the invention can also be used for the transfer of containers8between other processing devices, e.g. filling devices for containers, sterilization devices for containers and the like.

LIST OF REFERENCE NUMBERS