APPARATUS AND METHOD FOR HEATING PLASTIC PREFORMS WITH ADJUSTABLE FOCUSING DEVICE

Abstract

Provided is an apparatus for heating plastic preforms with a transport device which is suitable and intended for transporting the plastic preforms along a predetermined transport path, with at least one stationary arrange heating device which heats the plastic preforms transported along the transport path, wherein the heating device has at least one heating element which emits radiation which heats the plastic preforms and at least one focusing device which focuses the radiation emitted by the heating element onto predetermined regions of the plastic preforms to be heated, wherein a position of this focusing device is changeable.

Claims

1. An apparatus for heating plastic preforms with a transport device which is suitable and intended for transporting the plastic preforms along a predetermined transport path, with at least one stationary arranged heating device which heats the plastic preforms transported along the transport path, wherein the heating device has at least one heating element) which emits radiation which heats the plastic preforms, and at least one focusing device which focuses the radiation emitted by the heating element onto predetermined regions of the plastic preforms to be heated, wherein a position of this focusing device is changeable.

2. The apparatus according to claim 1, wherein the focusing device is adjustable together with the heating element.

3. The apparatus according to claim 1, wherein the focusing device is arranged on a movable carrier.

4. The apparatus according to claim 1, wherein the apparatus has a motorised drive device, for moving the focusing device.

5. The apparatus according to claim 1, wherein the apparatus has a control device which enables the focusing device to be moved as a function of the preforms to be heated.

6. The apparatus according to claim 4, wherein drive device enables a movement of the focusing device in at least one direction and/or a pivoting movement.

7. The apparatus according to claim 1, wherein the transport device has a circulating transport chain or a circulating transport belt.

8. The apparatus according to claim 1, wherein the focusing device comprises a reflector device and in particular a parabolic reflector device or elliptical reflector device.

9. A method for heating plastic preforms, wherein a transport device transports the plastic preforms along a predetermined transport path, and at least one stationary arranged heating device heats the plastic preforms) transported along the transport path, wherein the heating device has at least one heating element which emits radiation which heats the plastic preforms, and at least one focusing device which focuses the radiation emitted by the heating element onto predetermined regions of the plastic preforms to be heated, wherein a position of this focusing device is changed.

10. The method according to claim 9, wherein the position of the heating device is changed taking into account a plastic preform to be heated.

Description

BRIEF DESCRIPTION

[0056] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0057] FIG. 1 shows a plant according to embodiments of the invention for producing containers with an apparatus according to embodiments of the invention;

[0058] FIG. 2 shows a schematic representation of an apparatus according to embodiments of the invention;

[0059] FIG. 3 shows a diagram illustrating the adjustment of a focusing device;

[0060] FIG. 4 a further illustration of an apparatus according to embodiments of the invention;

[0061] FIG. 5 shows an illustration of a further movement mechanism for an apparatus according to embodiments of the invention; and

[0062] FIG. 6 shows a further illustration of a movement mechanism for an apparatus according to embodiments of the invention.

DETAILED DESCRIPTION

[0063] FIG. 1 shows a plant for manufacturing plastic containers. Plastic preforms 10 are separated by a separating device such as a single-cycle starwheel 15 and then transferred to an apparatus 1 for heating. This apparatus 1 for heating has a transport device 2 on which a plurality of holding elements 22 are arranged for holding the plastic preforms. The reference signs 4 indicate heating devices, which are arranged stationary here and which emit infrared radiation to the plastic preforms transported past the heating devices.

[0064] The plastic preforms are transported along a transport path P past a plurality of stationary heating devices 4.

[0065] After being heated, the plastic preforms are transferred to a transfer device 30, such as a distribution delay starwheel, from which they are in turn transferred to a forming device (not shown) for forming the plastic preforms into the plastic containers.

[0066] In addition, as shown in FIG. 1, the apparatus can also have a detection device 20 (shown schematically) for detecting plastic preforms. The data recorded by this detection device can be used to control the focussing device 44 (FIG. 2) or to track its movement.

[0067] The reference sign 16 indicates an input device by which the user can enter inputs to the apparatus. For example, the user could indicate via the input device which plastic preforms are to be heated and the control device 18 can then make an adjustment to the focusing device.

[0068] FIG. 2 shows a more detailed illustration of the apparatus according to embodiments of the invention. A plastic preform 10 is shown here, as well as a shielding device 26, which is intended to keep heat radiation away from a threaded region of this plastic preform. The reference sign 42 identifies a heating element, in particular a radiant heater, which is arranged within an elliptical reflector 46. The reference sign 44 accordingly identifies the focussing device and the reference sign 30 the carrier on which the focussing device but also the heating element 42 is arranged.

[0069] This carrier 30 is here adjustable or movable by two drive motors 32 and 34 in the X and Y directions shown in the figure, in order to position the focus of the radiant heaters on the plastic preform.

[0070] The reference sign 18 indicates a control device in the form of a machine control which is used to control the drive devices 32 and 34. For example, the drive device or the carrier 30 can be adjusted by a user command.

[0071] The reference sign 16 indicates the input device, such as an operating panel, through which the user can enter a positioning of the focusing device in addition to or as an alternative to the type of preform. This input device also particularly has a display on which the user of the focusing device and its movement are indicated.

[0072] FIG. 3 shows an illustration for carrying out an adjustment of the focusing device. Here, an adjustment device 52 is provided that can be detached or also permanently mounted. This has a sensing tip 54 which corresponds to a focus of the focusing device, for example the focal point of an elliptical reflector. This sensing tip can be guided to the plastic preform 10 in order to position it precisely.

[0073] FIG. 4 shows a further illustration of an apparatus according to embodiments of the invention. In addition to the focusing device, shielding screens 56 and 58 are also provided here to prevent radiation from reaching other areas of the plastic preform, such as its mouth area.

[0074] The reference signs 62 and 64 each indicate a tile and a counter-tile, which in turn serves to reflect radiation onto the plastic preform. Reference sign 66 indicates a bottom tile that is used to radiate or reflect heat onto the bottom area of the plastic preform.

[0075] FIG. 5 shows a further illustration showing a movement of the focusing device. In addition to the two drive devices 32 and 34, a rotary drive device 35 is also shown here, which enables the focusing device to be pivoted in order to facilitate its positioning.

[0076] In the illustration shown in FIG. 6, a parallel kinematic consisting of two drives 32 and 34 is provided, which also enables the focusing device 44 to be positioned with the heating element 42.

[0077] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0078] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements. The mention of a “unit” or a “module” does not preclude the use of more than one unit or module.

LIST OF REFERENCE SIGNS

[0079] 1 apparatus

[0080] 2 transport device

[0081] 4 heating device

[0082] 10 plastic preform

[0083] 15 single-cycle star

[0084] 16 input device

[0085] 18 control device

[0086] 20 detection device

[0087] 22 holding device

[0088] 26 shielding device

[0089] 30 carrier

[0090] 32, 34 drive device

[0091] 35 drive device

[0092] 42 heating element

[0093] 44 focusing device

[0094] 46 elliptical reflector

[0095] 52 adjustment device

[0096] 54 sensing tip

[0097] 56, 58 shielding screens

[0098] 62, 64 tile

[0099] 66 bottom tile

[0100] P transport path