Thermo-forming packaging machine with true-to-cycle positioning of a sealing station

Abstract

The invention relates to a thermo-forming packaging machine and a method which are characterized in that the location of trays in a base film upstream of a sealing station is detected by a measuring system and that the sealing station is immediately subsequently positioned such as to allow a top film to be sealed with highest accuracy matching the tray and thereby to be able to compensate for irregularities and tolerances, for example, in the film feed, in a true-to-cycle manner.

What is claimed is: 
     
         1 . Thermo-forming packaging machine comprising:
 a forming station for forming trays into a base film;   a device for introducing a reference element into said base film;   a sealing station including an adjustment device for adjusting the position of said sealing station along a direction of production and a displacement measuring device;   a measuring system at said sealing station or within a feed length upstream of said sealing station for determining the position of said reference element; and   a control unit configured to control the position of said sealing station according to the detected location of said reference element relative to said trays using said adjustment device;   wherein said thermo-forming packaging machine is adapted to be operated intermittently with the feed length for every work cycle.   
     
     
         2 . Thermo-forming packaging machine according to  claim 1 , wherein said measuring system is provided for contactless determination of the location of said reference element. 
     
     
         3 . Thermo-forming packaging machine according to  claim 1 , wherein said device is configured to introduce said reference element into said base film at a defined location relative to said trays, and wherein the location of said trays is detectable by detecting said reference element via said measuring system. 
     
     
         4 . Thermo-forming packaging machine according to  claim 1 , wherein said measuring system comprises a camera. 
     
     
         5 . Thermo-forming packaging machine according to  claim 1 , wherein said displacement measuring device is a magnetostrictive linear transducer. 
     
     
         6 . Thermo-forming packaging machine according to  claim 1 , wherein an adjustment range of said sealing station is provided of up to 1000 mm. 
     
     
         7 . Then no-forming packaging machine according to  claim 1 , wherein a further measuring system is provided for contactless determination of the location of said trays being supplied to a cutting station in a following work cycle and wherein said control unit is configured to control said cutting station according to the determined location of said trays in a true-to-cycle manner in its position relative to said trays using said further adjustment device. 
     
     
         8 . Thermo-forming packaging machine according to  claim 1 , wherein at least one of said forming station and said sealing station is movable into a tool exchange position. 
     
     
         9 . Thermo-forming packaging machine according to  claim 8 , wherein said control unit is configured to enter and store target positions of at least one of said forming station and said sealing station in formulae in said control unit. 
     
     
         10 . Method for operating a thermo-forming packaging machine including a forming station for forming trays into a base film, a sealing station, and a control unit, said method comprising the steps of:
 introducing a reference element into said base film;   determining the location of said reference element by a measuring system; and   positioning said sealing station in a predetermined position relative to said reference element using an adjustment device.   
     
     
         11 . Method according to  claim 10 , wherein said measuring system provides information by detecting said reference element based on which said control unit determines the location of said trays. 
     
     
         12 . Method according to  claim 10 , wherein said control unit detects the position of said sealing station using a displacement measuring device of said adjustment device aligned longitudinally along a direction of production. 
     
     
         13 . Thermo-forming packaging machine comprising:
 a forming station for forming trays into a base film;   a sealing station including an adjustment device for adjusting the position of said sealing station along a direction of production and a displacement measuring device;   a measuring system located within one feed length upstream of said sealing station for determining the location of said trays being supplied to said sealing station in the direction of production during a following work cycle; and   a control unit configured to control the position of said sealing station according to the determined location of said trays in a true-to-cycle manner in its position relative to said trays using said adjustment device;   wherein said thermo-forming packaging machine is adapted to be operated intermittently with a feed length for every work cycle.   
     
     
         14 . Thermo-forming packaging machine according to  claim 13 , wherein said measuring system is provided for contactless determination of the location of said trays. 
     
     
         15 . Thermo-forming packaging machine according to  claim 13 , wherein said forming station comprises a device for introducing a reference element into said base film at a defined location relative to said trays, and wherein the location of said trays is detectable via said measuring system by detecting said reference element. 
     
     
         16 . Thermo-forming packaging machine according to  claim 13 , wherein said measuring system comprises at least one of a camera and a reflex sensor. 
     
     
         17 . Thermo-forming packaging machine according to  claim 13 , wherein said displacement measuring device is a magnetostrictive linear transducer. 
     
     
         18 . Thermo-forming packaging machine according  claim 13 , wherein an adjustment range of said sealing station is provided of up to 1000 mm. 
     
     
         19 . Thermo-forming packaging machine according to  claim 13 , wherein a further measuring system is provided for contactless determination of the location of said trays being supplied to a cutting station during a following work cycle, and wherein said control unit is configured to control said cutting station according to the determined location of said trays in a true-to-cycle manner in its position relative to said trays using a further adjustment device. 
     
     
         20 . Thermo-forming packaging machine according to  claim 13 , wherein trend control for said forming station is set up using said control unit. 
     
     
         21 . Thermo-forming packaging machine according to  claim 13 , wherein at least one of said forming station and said sealing is movable into a tool exchange position. 
     
     
         22 . Thermo-forming packaging machine according to  claim 13 , wherein said control unit is configured to enter and store target positions of at least one of said forming station and said sealing station in formulae in said control unit. 
     
     
         23 . Method for operating a thermo-forming packaging machine including a forming station for forming trays into a base film, a sealing station, and a control unit, said method comprising the steps of:
 determining the location of the trays in one work cycle by a measuring system;   supplying said trays to said sealing station during a following work cycle; and   positioning said sealing station in a true-to-cycle manner relative to said trays using an adjustment device.   
     
     
         24 . Method according to  claim 23 , wherein said measuring system detects a reference element which has been introduced into said base film by a device of said forming station in order to transmit the location of said trays to said control unit. 
     
     
         25 . Method according to  claim 23 , wherein said control unit determines a trend from a changing location of said trays and adjusts the position of said forming station in relation to a direction of production using a further adjustment device. 
     
     
         26 . Method according to  claim 23 , wherein said control unit detects the position of said sealing station using a displacement measuring device of said adjustment device aligned longitudinally along a direction of production.