Vacuum packaging machine for the production of sealed packages

In a vacuum packing machine for producing sealed packages from a web of packing material, wherein a continuous chain drive is provided for moving the web, at least one working station is positioned adjacent the web on the chain drive for processing the web, means are provided for moving the chain drive, and means are provided for reciprocating the working station, whereby the web is processed by the working station while the web is being moved by the chain drive;

• the improvement wherein said means for moving said chain drive comprises rack means, said work station reciprocating means comprising a piston cylinder drive directly connected to reciprocate said rack means, a pair of gears positioned to mesh with the teeth of said rack means, a pair of sprockets connected to drive said chain drive, overrunning coupling means coupling each of said gears to a separate sprocket of said sprockets, whereby said sprockets drive said chain drive during times of opposite directions of movement of said rack means and said chain drive is substantially continuously driven in one direction, with each of said sprockets driving said chain drive only during one movement direction of said rack means, said means for reciprocating said working station comprising means directly connecting said rack to said working station for directly driving said working station to reciprocate synchronously with said rack means, whereby said working station is moved with the same speed as said chain drive by the same piston cylinder drive in response to a continuous square wave type application of the driving force by said piston cylinder drive, whereby all moving elements are driven in a locked manner and a sinus wave type application of force is avoided.