Acceleration sensor

An acceleration sensor comprising:

• an inertial mass disposed to inertially move when a vehicle suddenly decelerates;
• a trigger lever, a longitudinal direction portion of said trigger lever abutting a portion of a peripheral surface of said inertial mass at a side in a direction of inertial movement of said inertial mass, said trigger lever being pushed by said peripheral surface due to inertial movement of said inertial mass so as to rotate around a fulcrum from a first position to a second position, said trigger lever having a supporting shaft which is provided at said fulcrum, and having a trigger means which is provided integrally with said trigger lever at a position separated by a predetermined distance from said fulcrum and at a position which is different from a position at which said trigger lever abuts said inertial mass;
• an ignition pin which is movable from a non-actuating position, at which an occupant protection device is not actuated, to an actuating position, at which said ignition pint actuates the occupant protection device, in a direction substantially parallel to the direction of inertial movement of said inertial mass, said ignition pin having an engaging member, and when said trigger lever is at said first position, said engaging member engaging with said trigger means so as to restrain said ignition pin at said non-actuating position, and when said trigger lever is moved to said second position, said actuating member being released from engagement of said trigger means to move to said actuating position;
• and
• a spring member disposed to urge said ignition pin at said non-actuating position in a direction of said actuation position, and disposed to urge said trigger lever to apply urging force to said inertial mass in a direction opposite to the direction of inertial movement of said inertial mass for retaining said inertial mass at a non-actuating position during said engagement of said engaging member and said trigger means when said ignition pin is at said non-actuating position.

An acceleration sensor comprising:

• an inertial mass disposed to inertially move when a vehicle suddenly decelerates;
• a trigger lever, a longitudinal direction portion of said trigger lever abutting a portion of a peripheral surface of said inertial mass at a side in a direction of inertial movement of said inertial mass, said trigger lever being pushed by said peripheral surface due to inertial movement of said inertial mass so as to rotate around a fulcrum from a first position to a second position, said trigger lever being formed from a single plate-shaped member and having a trigger portion which is provided integrally with said trigger lever at a position separated by a predetermined distance from said fulcrum and at a position which is different from a position at which said trigger lever abuts said inertial mass;
• an ignition pin which is movable from a non-actuating position, at which an occupant protection device is not actuated, to an actuating position, at which said ignition pin actuates the occupant protection device, in a direction substantially parallel to the direction of inertial movement of said inertial mass, said ignition pin having an engaging member, and when said trigger lever is at said first position, said engaging member engaging with said trigger portion so as to restrain said ignition pin at said non-actuating position, and when said trigger lever is moved to said second position, said actuating member being released from engagement of said trigger portion to move to said actuating position;
• and
• a spring member which disposed to urge said ignition pin at said non-actuating position in a direction of said actuating position, and disposed to urge said trigger lever to apply urging force to said inertial mass in a direction opposite to the direction of inertial movement of said inertial mass for retaining said inertial mass at a non-actuating position during said engagement of said engaging member and said trigger means when said ignition pin is at said non-actuating position.