Control mechanism for tilting device of strapping machine comprising: - an epicyclic transmission defining a main axis and comprising an inner crown, a plurality of intermediate gears and an external crown, - a pulling mechanism operatively connected to said intermediate gears and to a tensioning roller of said tilting device and configured to transmit the movement of said internal gears around said main axis to said tensioning roller, - a tensioning wheel centred with respect to said main axis integrally constrained to said inner crown and operatively connected to a tensioning assembly of said strapping machine in such a way as to transmit the movement of said tensioning wheel imposed by said tensioning assembly to said inner crown, - a locking device operationally connected to said external crown and configured to realize at least: - a lock condition in which said locking device and said external crown are coupled in such a way as to create a constraint joint, - an unlock condition wherein at least part of said locking device and said external crown are decoupled in such a way as to be movable independently, - a control device configured to interact with an actuation lever of said strapping device, operatively connected to said locking device in such a way as to transmit at least part of the movement of said actuation lever to said locking device, and defining at least one resting position and a first actuation position wherein said control device has performed a first predetermined movement imposed by said actuation lever, and being characterized by that - said locking device includes: - a ring centred with respect to said main axis and integral with said external crown, and - a torsional spring constrained between a fixed point of said tilting device and said control device, centred with respect to said main axis and configured to tighten around said ring to realize said lock condition or widen around said ring in such a way as to realize said release condition. - an epicyclic transmission defining a main axis and comprising an inner crown, a plurality of intermediate gears and an external crown, - a pulling mechanism operatively connected to said intermediate gears and to a tensioning roller of said tilting device and configured to transmit the movement of said internal gears around said main axis to said tensioning roller, - a tensioning wheel centred with respect to said main axis integrally constrained to said inner crown and operatively connected to a tensioning assembly of said strapping machine in such a way as to transmit the movement of said tensioning wheel imposed by said tensioning assembly to said inner crown, - a locking device operationally connected to said external crown and configured to realize at least: - a lock condition in which said locking device and said external crown are coupled in such a way as to create a constraint joint, - an unlock condition wherein at least part of said locking device and said external crown are decoupled in such a way as to be movable independently, - a control device configured to interact with an actuation lever of said strapping device, operatively connected to said locking device in such a way as to transmit at least part of the movement of said actuation lever to said locking device, and defining at least one resting position and a first actuation position wherein said control device has performed a first predetermined movement imposed by said actuation lever, and being characterized by that - said locking device includes: - a ring centred with respect to said main axis and integral with said external crown, and - a torsional spring constrained between a fixed point of said tilting device and said control device, centred with respect to said main axis and configured to tighten around said ring to realize said lock condition or widen around said ring in such a way as to realize said release condition.