Abstract: In a packaging machine that includes a wrapping wheel equipped with at least one conveying head affording a seat capable of movement with the wrapping wheel along a looped path, the head is indexed through a first station at which the seat receives a product, a second station where a wrapping sheet is taken up and held stably by a gripper mechanism across an opening of the seat, in a predetermined position, and an outfeed station at which the product is ejected from the seat and caused to associate with the wrapping sheet, whereupon product and sheet are transferred together to a further wrapping wheel; the machine is equipped with a device located externally of the wrapping wheel by means of which to actuate the gripper mechanism.