Emergency unlocking mechanism for door of automobile

A locking system for an automobile door comprising:

• a locking unit for locking and unlocking the door, said lock unit having a locking position in which the door is locked and an unlocking position in which the door is not locked,
• input means,
• linkage means, connected between said input means and said lock unit, for transmitting movement from said input means to said lock unit and thereby making it possible to cause said lock unit to move from its locking position to its unlocking position or vice versa by moving said input means, said linkage means having a lock directing position in which said lock unit is in said locking position and an unlock directing position in which said locking unit is in said unlocking position, said linkage means comprising a movable member having a receiving portion, and
• inertia actuating means comprising pushing means having a weight portion swingable in a vertical plane about a fulcrum from a normal position into a first actuating position and an actuating portion which moves together with said weight portion, lies adjacent to said receiving portion of said linkage means when said linkage means is in said lock directing position and said weight portion is in said normal position, and pushes said receiving portion to move said lock unit from its locking position to its unlocking position by moving said linkage means from said lock directing position to said unlock directing position when said weight portion swings from said normal position to said first actuating position, said inertia actuating means further comprising holding means which comprises a spring for normally holding said weight portion in said normal position irrespective of whether said linkage means is in said lock directing position or in said unlock directing position, and allowing said weight portion to swing from said normal position to said first actuating position by reason of its inertia when vehicle deceleration at a rate higher than a predetermined level takes place, said linkage means being capable of moving between said lock and unlock directing positions without causing said inertia actuating means to move as long as said weight portion is held in said normal position, said pushing means comprising an inertia lever which has a lower end having said weight portion and an upper end having said fulcrum and is capable of swinging in said vertical plane on said fulcrum from said normal position to said first actuating position, said inertia lever being capable of swinging into a second actuating position opposite to said first actuating position by reason of its inertia when a vehicle acceleration of a rate higher than a predetermined level takes place, said inertia actuating means causing said linkage means to move from its lock directing position to its unlock directing position when said inertia lever swings from its normal position to its second actuating position.