Patent ID: 9555534
Date: 2017-01-31
CPC Classifications: B25B,B25F

Claim:
1. A rotary screw driving tool comprising: a handle housing comprising a handle and lodging a motor; and a gear reduction housing, said gear reduction housing lodging a gear reduction unit, an input of which cooperating with an output of said motor, said gear reduction unit comprising a single output cooperating with a rotating end element that is configured for cooperating with an element to be screwed, said gear reduction housing being linked to said handle housing by a rotating link, which is configured in a way such that a reduced reaction force is transmitted to said handle housing during an operation of screw driving, said rotating link comprising a transmission, which transmits to said handle housing a reaction torque having an intensity that is substantially identical, and a direction that is opposite, to that of the reaction torque transmitted by said gear reduction unit to said motor, said gear reduction unit comprising a first epicyclic gear train having a first sun gear interdependent with said motor, at least two first planet gears mounted on a first planet carrier, and a ring gear mounted freely in rotation in said gear reduction housing, said transmission comprising a second epicyclic train having said ring gear, a second sun gear mobile in rotation relative to said first sun gear and fixed to said handle housing, at least two second planet gears mounted on a second planet carrier, said second planet carrier being fixed to said gear reduction housing.