The utility model discloses a semi -tangent formula is around chartered plane with putting around packing, including the chassis, fix at the supporting seat of chassis one end and fix the tailstock at the chassis other end, the motor that is fixed with on the chassis is equipped with little synchronizing wheel in the axis of rotation of motor, be fixed with the main shaft on the supporting seat, be equipped with big synchronizing wheel on the main shaft and wind the package rotor, big synchronizing wheel passes through the hold -in range and is connected with little synchronizing wheel, around the package rotor still with the tailstock on the empty spindle connection of tailstock. The utility model has the advantages that: the variable speed is accomplished by the motor speed governing, for the tradition around the chartered plane, its rotational speed is higher, production efficiency is showing and is improving, motor variable velocity zone encoder feedback signal, the real -time tracking, the band pitch of the cable external sheath of producing is more stable, in the time of can not shutting down because of the start speed the unstability and influence the stability of band pitch, being equipped with persevering tension device's band dish, going out to take tension more even, it appears breaking to be difficult for takes, the cladding is loose, the phenomenon of turn -up.