Patent ID: 8291783

Claim:
A helical locking mechanism for a door, comprising: exactly one power source ( 11 ); exactly one screw ( 1 ) having an axis and a helical slot ( 20 ), the slot ( 20 ) divided into i) a working section (C) with a lead angle more than a friction angle, ii) a locking section (A) with a lead angle less than a friction angle, and iii) a transition section (B) located between the working section (C) and the locking section (A), a lead angle of the transaction section varying; and a self-adaptive nut ( 19 ) assembled with the screw ( 1 ), wherein, in use, the self-adaptive nut ( 19 ) is connected with the door ( 10 ), the self-adaptive nut ( 19 ) comprising a spindle sleeve ( 7 ) connected to a pin shaft ( 5 ), the pin shaft ( 5 ) located in the screw slot ( 20 ) and in linear contact with the screw slot ( 20 ), the pin shaft ( 5 ) and screw slot ( 20 ) realizing a matched screw kinematic pair to transfer power and motion from the power source ( 11 ), via the bidirectionally rotation of the screw ( 1 ), to the self-adaptive nut ( 19 ), wherein the screw ( 1 ) is connected to the power source ( 11 ), the power source ( 11 ) driving the screw ( 1 ) to rotate bidirectionally, the power source ( 11 ) further driving the self-adaptive nut and the door to move synchronously in parallel with the axis of the screw, with the self-adaptive nut entering and exiting the locking section (A) to realize the locking and self-unlocking of door.