Solenoid ratchet mechanism

A thrust reverser assembly, comprising:

• a lock system including a lock shaft, a solenoid and a ratchet;
• the lock shaft movable along a longitudinal axis in a first direction towards an unlocked position and in a second direction towards a locked position;
• the solenoid including a body and an armature, the armature configured to move through a solenoid stroke distance towards the body in the first direction on activation of the solenoid, the armature configured to move back through the solenoid stroke distance away from the body in the second direction on deactivation of the solenoid, and an activation cycle of the solenoid comprises one activation and one deactivation of the solenoid;
• the ratchet assembly including a holding pawl, a driving pawl and a plurality of axially spaced ratchet protrusions, the holding pawl including a holding pawl pivot point about which the holding pawl is pivotable, the holding pawl pivot point fixed relative to the body, the driving pawl including a driving pawl pivot point about which the driving pawl is pivotable, the driving pawl pivot point fixed relative to the armature, and the plurality of axially spaced ratchet protrusions fixed relative to the lock shaft;
• wherein the driving pawl is configured to engage with a ratchet protrusion so as to drive movement of the lock shaft in the first direction on movement of the armature in the first direction and to release from engagement with the ratchet protrusion so as to move relative to the lock shaft on movement of the armature in the second direction;
• wherein the holding pawl is configured to allow the lock shaft to move relative to the body when the driving pawl is driving movement of the lock shaft, and to engage with a ratchet protrusion so as to limit axial movement of the lock shaft relative to the body while the driving pawl is moving in the second direction;
• and
• wherein the lock system is configured to repeat the activation cycle so as to drive the lock shaft in the first direction by a distance corresponding to a number of repetitions of the activation cycle multiplied by the solenoid stroke distance.

A method of operating a lock system, comprising:

• providing the lock system comprising a lock shaft, a solenoid and a ratchet;
• activating the solenoid so as to drive the lock shaft in a first direction by a first distance corresponding to a solenoid stroke distance;
• deactivating the solenoid to move an armature of the solenoid and a driving pawl of the rachet back through the solenoid stroke distance away from a body of the solenoid in a second direction while a holding pawl of the ratchet limits axial movement of the lock shaft relative to the body by engagement with a ratchet protrusion;
• and
• repeatedly activating and deactivating the solenoid so as to drive the lock shaft in the first direction by a second distance corresponding to a number of repetitions of an activation cycle multiplied by the solenoid stroke distance.