Vehicle door latch with inertial lock

1. A latch assembly for vehicle doors, the latch comprising:

a fork-bolt movable between an engaged position and a disengaged position, and wherein the fork-bolt is configured to grasp a striker on a vehicle body structure when the fork-bolt is in the engaged position to retain a vehicle door in a closed position;

a pawl member that selectively engages the fork-bolt and prevents movement of the fork-bolt from the engaged position to the disengaged position when the pawl member engages the fork-bolt, the pawl member permitting movement of the fork-bolt from the engaged position to the disengaged position when the pawl member is disengaged from the fork-bolt;

a movable pawl operating lever assembly that is configured to move the pawl member to disengage the pawl member from the fork-bolt to permit movement of the fork-bolt from the engaged position to the disengaged position;

an outside release member movable between rest and released positions;

an internal lock member that is movable about a generally horizontal lock axis between locked and unlocked positions, wherein the lock axis extends in a fore-aft vehicle direction;

wherein:

when the internal lock member is in the unlocked position, movement of the outside release member from the rest position to the released position causes the pawl operating lever assembly to engage the pawl member and disengage the pawl member from the fork-bolt to permit movement of the fork-bolt from the engaged position to the disengaged position;

when the internal lock member is in the locked position, movement of the outside release member from the rest position to the released position does not cause the pawl operating lever assembly to engage the pawl member, such that the fork-bolt cannot move from the engaged position to the disengaged position;

the internal lock member defines a center of mass that is offset from the lock axis such that a transverse acceleration due to a side impact on a vehicle door to which the latch assembly is installed causes the internal lock member to rotate from its unlocked position to its locked position such that when the outside release member moves from the rest position to the released position due to the impact, and the pawl member remains engaged with the fork-bolt and prevents movement of the fork-bolt from the engaged position to the disengaged position;

the movable pawl operating lever assembly defines a locked configuration and an unlocked configuration;

the internal lock member is operably interconnected to the movable pawl operating lever assembly and shifts the movable pawl operating lever assembly from the locked configuration to the unlocked configuration when the internal lock member rotates from the locked position to the unlocked position; and

the movable pawl operating lever assembly comprises an operating lever, an outside intermediate lever, and an inside intermediate lever, wherein the operating lever rotates about the lock axis.

2. A vehicle door comprising:

a latch;

an outside handle movable between a rest position and an open position;

an outside release lever;

a lever assembly having locked and unlocked configurations, wherein the lever assembly mechanically couples the outside handle to the latch via the outside release lever when the lever assembly is in the unlocked configuration and mechanically unlatches the latch when the handle moves from the rest position to the open position when the lever assembly is in the unlocked configuration, and wherein the lever assembly mechanically de-couples the outside handle from the latch when the lever assembly is in the locked configuration such that movement of the outside handle from the rest position to the open position does not unlatch the latch when the lever assembly is in the locked configuration;

a lock member that rotates due to inertial forces and causes the lever assembly to change from the unlocked configuration to the locked configuration whereby the lever assembly is mechanically de-coupled from the outside release lever and the latch upon impact on the door whereby the latch remains latched as the handle moves from the rest position to the open position upon impact.

3. The vehicle door of claim 2 , wherein:

the outside handle rotates about a generally vertical axis between the rest position and the open position.

4. The vehicle door of claim 2 , wherein:

the latch includes a rotatable fork-bolt that is configured to engage a striker to retain the door in a closed position, and a pawl that selectively engages the fork-bolt when the latch is latched to prevent rotation of the fork-bolt.

5. The vehicle door of claim 2 , wherein:

the lock member rotates about a generally horizontal axis, and wherein the lock member has a center of gravity that is vertically spaced apart from the axis.