Method and device for wrapping groups of stacked products in the manufacture of sealed packs

4) A device for wrapping groups of stacked products in the manufacture of sealed packs, comprising:

• feed means serving to position a sheet (4) of wrapping material over a group (1) of products;
• pusher means by which the group (1) of products is directed against the sheet (4) and through a folding shoe (5) in such a way that the sheet is bent around the group (1) to assume a “U” profile;
• a wrapping wheel (7) equipped with a plurality of conveying pockets (6) each serving to accommodate a group (1) of products enveloped by a relative sheet with two side edges (8) of the sheet (4) projecting radially from the pocket (6), and rotatable in such a manner as to direct each successive group (1) of products through respective wrapping stations comprising a heat-sealer (9) serving to unite the two opposite side edges (8) of the sheet (4), creating a tubular wrapper (12) with two end portions (14) projecting externally of the relative pocket (6), a tongue (16) by which the end portion (14) is deformed and caused to assume a flattened appearance, also heat-sealing means (17) capable of movement toward and away from one another and serving to seal the flattened end portions (14), and a folding unit (21) serving to fold the sealed end portions (14) against the respective end faces of the group (1) of products;
• characterized in that the folding unit (21) comprises a first folder element (22) and a second folder element (23) presenting respective contact ends (22a, 23a) capable of movement between a position distanced one from the other and a position of mutual proximity in which the respective sealed end portion (14) of the wrapper is crimped between the contact ends to generate crease lines (24) dividing the selfsame end portion (14) into a central portion (25) and two lateral portions (26).