Packaging machine

Abstract

A packaging machine includes a pair of sealing members, a cutting device and a switching unit. The sealing members are configured to selectively seal a cylindrical packing material that extends therebetween. The cutting device includes a pressing member arranged on one of the pair of sealing members and a receiving member arranged on the other of the pair of sealing members. The cutting device is configured to selectively press the pressing member against the receiving member to melt and cut the cylindrical packaging material by heat and pressure. The switching unit is configured to switch the pressing member between a pressing state and a non-pressing state with respect to the receiving member when the sealing members are pressed together. The stopping unit is configured to selectively stop the pressing member from retracting from the pressing state with respect to the receiving member.

1 . A packaging machine comprising: 
 a pair of sealing members configured to selectively seal a cylindrical packing material that extends therebetween;    a cutting device including a pressing member arranged on one of the pair of sealing members and a receiving member arranged on the other of the pair of sealing members, the cutting device being configured to selectively press the pressing member against the receiving member to melt and cut the cylindrical packaging material by heat and pressure;    a switching unit configured to switch the pressing member between a pressing state and a non-pressing state with respect to the receiving member when the sealing members are pressed together; and    a stopping unit configured to selectively stop the pressing member from retracting from the pressing state with respect to the receiving member.    
     
     
         2 . The packaging machine according to  claim 1 , wherein 
 the switching unit comprises a drive source configured to cause the pressing member to protrude a predetermined distance from the sealing surface of the sealing member, and a force augmenting mechanism configured to transmit the motive energy of the drive source to the pressing member; and    the stopping unit employs the force augmenting mechanism to stop the pressing member from retracting.    
     
     
         3 . The packaging machine according to  claim 2 , wherein 
 the force augmenting mechanism is comprised of a toggling mechanism having at least one link; and    the pressing member is stopped from retracting by reducing the angle formed by the longitudinal direction of the at least one link of the toggling mechanism and the movement direction of the pressing member.    
     
     
         4 . The packaging machine according to  claim 2 , wherein 
 the force augmenting mechanism is comprised of a cam mechanism having at least one cam; and    the pressing member is stopped from retracting by making the tangential direction of the at least one cam of the cam mechanism, which is measured at a contacting point between the at least one cam and the pressing member, to be substantially orthogonal to the movement direction of the pressing member.    
     
     
         5 . The packaging machine according to  claim 1 , wherein 
 the switching unit comprises an urging unit that urges the pressing member forward, a mobile member that moves freely between an inhibiting position that inhibits the pressing member from retracting and a permitting position that permits the pressing member to retract, and a drive source configured to drive the mobile member to the inhibiting position and the permitting position; and    the mobile member is employed as the stopping unit.    
     
     
         6 . The packaging machine according to  claim 1 , further comprising: 
 an adjusting unit configured to adjust the pressing force of the pressing member when the pressing member is pressed together with the receiving member.    
     
     
         7 . The packaging machine according to  claim 1 , wherein 
 the switching unit is configured to switch the pressing member from the pressing state to the non-pressing state when the sealing members are pressed together.