Device for joining the trailing edge of a reel of paper about to finish to the leading edge of a new reel

A device for joining the trailing edge of a reel of paper about to finish to the leading edge of a new reel comprising, on a supporting structure (11), a support (12) for the reel as it unwinds (13), a device (15) for transferring the reel (13) to a unit for tensioning the trailing edge (17) of the reel (13′) about to finish, a cutting unit (32) of said trailing edge (17), at least one roller (43) that presses said trailing edge (17) on said new reel (13) once it has been positioned on said support (12) and the new reel provided with a double-sided tape (48) positioned crosswise on a lateral surface of the same in order to retain its leading edge (49) wherein said tensioning unit consists of four supporting wheels (18) arranged two per side designed to house and move the ends of the rods (16) supporting the reel about to finish (13′), said wheels (18) being driven by a pair of gearmotors (19) arranged one per side and connected by a belt transmission (20) with insertion of a ball torque limiting device (21).