Device for automatically locking the pressure lid in electric pressure cookers

A device for automatically locking or unlocking a pressure lid in an electric pressure cooker, comprising the pressure lid mounted to a bottom side of a cooker's top lid with a gap therebetween, said pressure lid having a plurality of outward protrusions radially extending outward from a peripheral edge of said pressure lid;

• a lock ring movably placed on a lower guide rail and positioned around the peripheral edge of said pressure lid, said ring having a plurality of inward protrusions radially extending inward from the top of a side wall of said ring, said inward protrusions selectively engaging with said outward protrusions of the pressure lid to lock said pressure lid to said ring;
• and a plurality of guide rollers mounted to the bottom of said lock ring and rolling on said guide rail when said lock ring is rotated, further comprising:
• a spur gear carrier extending downward from a part of an outside bottom portion of said lock ring, said carrier passing downward through a guide slit in said guide rail and having a spur gear part on its outside surface;
• a drive gear gearing into said spur gear part, said drive gear being fixed to an output shaft of a reversible motor, said motor being connected to a microcomputer through a motor drive integrated circuit;
• a lock sensing switch and an unlock sensing switch placed around said lock ring in close vicinity to said ring;
• a contact protrusion provided on a peripheral edge of said lock ring and selectively coming into contact with one of said sensing switches in accordance with a rotating motion of said lock ring, thereby turning on the one switch and automatically locking or unlocking said inward protrusions of the lock ring relative to said outward protrusions of the pressure lid.