Cutting unit for a packaging machine in extendable film

A cutting unit for a packaging machine for separating a series of finished packages (16) containing a predetermined number of products (11), from a continuous bundle advancing on a conveyor (14), comprising:

• a frame (20);
• and
• two pairs of cutting elements, comprising a pair of side cutting elements (21) supported by the frame and a pair of upper cutting elements (22s,22s′) and lower cutting elements (22i,22i′) arranged facing four sides of the continuous bundle,
• wherein said two pairs of cutting elements (21;
• 22s, 22s′, 22i, 22i′) can be alternately moved forwards and backwards between a rest position separated from said continuous bundle and an engagement position on the continuous bundle containing groups of the products (11), arranged on two adjacent rows and wrapped in a film of extensible plastic material (15), and
• wherein each pair of the cutting elements (21;
• 22s, 22s′, 22i, 22i′) is driven in an alternating forward and backward movement for engagement with, and disengagement from, the continuous bundle by a double crank (23, 23′;
• 27, 27′) actuated by a single motor (24;
• 28).