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. <EOS>