Patent ID: 8621716

Claim:
A rotation shaft angle positioning device for a foldable electronic device having a cover and a body pivotally connected to each other, wherein the rotation shaft angle positioning device comprises: a device axis and a driving axis parallel to and spaced from the device axis; a first pivot portion adapted to be connected to one of the cover and the body, comprising: a shaft along the device axis, and a flange, with the flange comprising: a lower surface and an upper surface connected by a ramped converging portion, and a positioning protrusion extending from the shaft adjacent a corner of the lower surface and the ramped converging portion; and a second pivot portion comprising a driving unit along the driving axis parallel to and spaced from the device axis, and adapted to pivotally connect to the other of the cover and the body, with the driving unit comprising: a hook portion and a spring unit connected to the hook portion, wherein the spring unit urges the hook portion towards the shaft and the lower surface of the first pivot portion; and wherein: movement of the rotation shaft angle positioning device in a first rotational direction is different than the movement along an opposite rotational direction, rotation of the first pivot portion in the first direction allows the cover to rotate through a locking position between the positioning protrusion and the corner, with the hook portion rotating against the lower surface, the positioning protrusion, the ramped converging portion and the upper surface in turn, and rotation of the first pivot portion in the opposite direction allows the cover to rotate without rotating through the locking position, with the hook portion rotating against the upper surface, the surface coplanar to the upper surface and the lower surface in turn.