Continuous motion sealing apparatus for packaging machine

Abstract

A sealing apparatus is especially adapted for a packaging machine which wraps spaced-apart products with a tubular film. The apparatus includes a frame which provides a path along which the products are advanced. A sealing support structure is mounted on the frame for linear reciprocating movement along the path. A crank arm is rotatably mounted on the frame for reciprocating the sealing support structure. Upper and lower sealing dies are mounted on the sealing support structure for linear movement toward and away from each other in a direction which is generally perpendicular to the path.

I claim:  
     
         1 . A sealing apparatus for sealing spaced-apart produts which are enclosed by a film comprising: 
 a frame, the frame providing a path along which spaced-apart products can move,    a sealing support structure mounted on the frame for movement along said path,    upper and lower sealing units mounted on the sealing support structure for movement toward and away from each other in a direction which is generally perpendicular to said path,    means for moving the upper and lower sealing units toward each other to close the sealing units whereby a film between the sealing units can be sealed and for moving the upper and lower sealing units away from each to open the sealing units, and    means for reciprocating the sealing support along said path between first and second positions.    
     
     
         2 . The apparatus of  claim 1  in which the sealing support structure is mounted on the frame for linear reciprocating movement along said path.  
     
     
         3 . The apparatus of  claim 2  in which the upper and lower sealing units are mounted on the sealing support structure for linear movement toward and away from each other.  
     
     
         4 . The apparatus of  claim 1  in which the upper and lower sealing units are mounted on the sealing support structure for linear movement toward and away from each other.  
     
     
         5 . The apparatus of  claim 1  in which said means for moving the upper and lower sealing units includes a servo motor.  
     
     
         6 . The apparatus of  claim 5  in which the means for moving the upper and lower sealing units includes a belt drive which is driven by said servo motor.  
     
     
         7 . The apparatus of  claim 1  in which said means for reciprocating the sealing support structure includes a crank arm rotatably mounted on the frame and a link connecting the crank arm and the sealing support structure.  
     
     
         8 . The apparatus of  claim 7  including a servo motor for rotating the crank arm.  
     
     
         9 . The apparatus of  claim 7  including a linear bearing between the sealing support structure and the frame for supporting the sealing support structure for linear movement along said path.  
     
     
         10 . The apparatus of  claim 9  including a linear guide on the sealing support structure, the upper and lower sealing units being mounted on the linear guide for linear movement toward and away from each other.  
     
     
         11 . The apparatus of  claim 7  including a linear guide on the sealing support structure and linear bearings on the upper and lower sealing units for supporting the sealing units for linear movement along said path.  
     
     
         12 . The apparatus of  claim 1  including a linear guide on the frame and a linear bearing on the sealing support structure for supporting the sealing support structure for linear movement along said path.  
     
     
         13 . The apparatus of  claim 1  in which said means for reciprocating the sealing support structure includes a belt drive mounted on the frame and connected to the sealing support structure.  
     
     
         14 . The structure of  claim 1  including a linear guide on the frame which extends in the direction of said path and a linear bearing on the sealing support structure for supporting the sealing support structure for linear movement along said path.  
     
     
         15 . The apparatus of  claim 1  including a pair of linear guides on the sealing support structure which extend generally perpendicularly to said path, a pair of bearings on each of the upper and lower sealing units slidably mounted on the linear guides for linear movement toward and away from each other.  
     
     
         16 . The apparatus of  claim 15  including upper and lower cross members connected to said pair of linear guides, and means for moving said upper and lower cross members and said linear guides in a direction which is generally perpendicular to said path.  
     
     
         17 . The apparatus of  claim 16  in which said linear guides are slidably mounted in said sealing support structure.  
     
     
         18 . The apparatus of  claim 18  in which said means for moving includes a threaded shaft connected to one of the upper and lower cross members and extending through said sealing support structure whereby rotation of the threaded shaft moves said upper and lower cross members and said linear guides relative to said sealing support structure.  
     
     
         19 . The apparatus of  claim 16  including upper pulleys rotatably mounted on the upper cross member and lower pulleys rotatably mounted on the lower cross member, a pair of drive belts extending over the upper and lower pulleys, and means for rotating the upper or lower pulleys to move the drive belts, the upper and lower sealing units being connected to the drive belts for movement with the drive belts.  
     
     
         20 . The apparatus of  claim 15  including upper pulleys rotatably mounted on the upper cross member and lower pulleys rotatably mounted on the lower cross member, a pair of drive belts extending over the upper and lower pulleys, and means for rotating the upper or lower pulleys to move the drive belts, the upper and lower sealing units being connected to the drive belts for movement with the drive belts.