Abstract: A transformable stratospheric airship includes an upper shell, a lower shell, a foldable hull, and a plurality of cable control mechanisms provided on the upper shell and the lower shell. The foldable hull includes a sealed body, a plurality of guide holes arranged outside the sealed body and a cable which passes through the guide holes according to a predetermined order. The cable is configured to keep a shape of the sealed body and connected to the cable control mechanisms to fix the sealed body to the upper shell and the lower shell. The foldable hull is foldable and extendable along a vertical direction of the transformable stratospheric airship by controlling a length of the cable via the cable control mechanisms.

Abstract: A transformable stratospheric airship includes an upper shell, a lower shell, a foldable hull, and a plurality of cable control mechanisms provided on the upper shell and the lower shell. The foldable hull includes a sealed body, a plurality of guide holes arranged outside the sealed body and a cable which passes through the guide holes according to a predetermined order. The cable is configured to keep a shape of the sealed body and connected to the cable control mechanisms to fix the sealed body to the upper shell and the lower shell. The foldable hull is foldable and extendable along a vertical direction of the transformable stratospheric airship by controlling a length of the cable via the cable control mechanisms.

Abstract: An impact screwdriver includes a housing, a battery arranged in the housing, an electric motor arranged inside the housing, a transmission part driven by the electric motor and an impacting part, the impacting part including a hammer, an anvil matched to and hammered by the hammer, and an output shaft revolved by the anvil, wherein the rated voltage of the battery is less than or equal to 4.25V, the impact frequency of the hammer and the anvil is at least 30 Hz, and the ratio of the output torque (Nm) of the output shaft to the rated voltage of the battery is 1.8˜4.5.

Abstract: An impact screwdriver includes a housing, a battery arranged in the housing, an electric motor arranged inside the housing, a transmission part driven by the electric motor and an impacting part, the impacting part including a hammer, an anvil matched to and hammered by the hammer, and an output shaft revolved by the anvil, wherein the rated voltage of the battery is less than or equal to 4.25V, the impact frequency of the hammer and the anvil is at least 30 Hz, and the ratio of the output torque (Nm) of the output shaft to the rated voltage of the battery is 1.8˜4.5.