Lifting mechanism with interlock and method

Abstract

The disclosure relates to a lifting mechanism for opening and closing a tool of a packaging machine. The lifting mechanism comprises at least one first lifting device and at least one second lifting device which can be actuated in succession in order to move the lifting mechanism from an open position to a closed position, wherein the first lifting device is decoupled from a load absorption caused by means of the second lifting device for closing the tool. The lifting mechanism comprises at least one adjustable locking mechanism for force-related decoupling of the first lifting device from a force flow caused by the second lifting device. Furthermore, the disclosure relates to a corresponding method.

What is claimed is: 
     
         1 . A lifting mechanism for opening and closing a tool of a packaging machine, wherein the lifting mechanism comprises a first lifting device and a second lifting device which can be actuated in succession in order to move the lifting mechanism from an open position to a closed position, wherein the first lifting device is decoupled from a load absorption caused by means of the second lifting device for closing the tool, wherein the lifting mechanism comprises an adjustable locking mechanism for force-related decoupling of the first lifting device from a force flow caused by the second lifting device. 
     
     
         2 . The lifting mechanism according to  claim 1 , wherein the locking mechanism for the force-related decoupling of the first lifting device from the force flow caused by the second lifting device can be clamped by at least one component formed on the first lifting device. 
     
     
         3 . The lifting mechanism according to  claim 1 , wherein the locking mechanism comprises an adjusting drive which can be controlled separately from the first and second lifting devices. 
     
     
         4 . The lifting mechanism according to  claim 1 , wherein the lifting mechanism comprises at least one base plate supported by a tie rod and adjustably mounted along the tie rod by means of the first lifting device. 
     
     
         5 . The lifting mechanism according to  claim 1 , wherein the lifting mechanism comprises at least one height-adjustable stop for stopping a lifting movement of a tool holder used to support a tool upper part. 
     
     
         6 . The lifting mechanism according to  claim 5 , wherein the first lifting device comprises at least one lifting cylinder with an extendable piston, which is controllable for closing the tool both for adjusting the tool upper part and for adjusting a tool lower part. 
     
     
         7 . The lifting mechanism according to  claim 6 , wherein the second lifting device comprises at least one inflatable membrane for lifting the tool lower part. 
     
     
         8 . A packaging machine formed as a deep-drawing packaging machine or a tray-sealing machine, comprising the lifting mechanism according to  claim 1 . 
     
     
         9 . A method for opening and closing a tool of a packaging machine by means of a lifting mechanism formed thereon, the method comprising:
 actuating a first lifting device and a second lifting device in succession for adjusting the lifting mechanism from an open position to a closed position, wherein the first lifting device is decoupled from a load absorption caused by means of the second lifting device for closing the tool; and   adjusting a locking mechanism between a base plate of the lifting mechanism, which is adjustable by means of the first lifting device, and a cylinder plate formed on a lifting cylinder of the first lifting device.   
     
     
         10 . The method according to  claim 9 , wherein the locking mechanism is clamped between the base plate and the cylinder plate for force decoupling of the first lifting device from a force flow caused by the second lifting device.