Extendable and retractable knee bolster system

A knee bolster system for a vehicle comprising:

• a vehicle structure;
• at least one telescoping mechanism having a base end and a free end, the base end engaged to the vehicle structure, the free end capable of linear translation with respect to the base end;
• a knee bolster pad attached rigidly to each free end of the at least one telescoping mechanism;
• at least one actuator secured to the base end of the respective one of the at least one telescoping mechanism, the actuator operative to move the telescoping mechanism between a retracted position and an extended position, the at least one actuator having:
• a shuttle disposed operatively and interconnected to the free end of the telescoping mechanism, and
• a drive device interconnected to the shuttle and operative to effect back and forth linear translation of the shuttle;
• at least one plowing mechanism operative to limit the linear translation of the at least one telescoping mechanism in response to a forward force from an occupant of the vehicle during a crash;
• a microprocessor capable of receiving electrical signal inputs from a plurality of sensor outputs and processing extend and retract flags to electrically control the drive device;
• an inner tube having a leading end, a trailing portion, and an outer cylindrical wall;
• an outer tube engaged rigidly to the vehicle structure and disposed concentrically with the inner tube, the outer tube having the base end, a free end and an inner cylindrical wall, the outer cylindrical wall of the inner tube facing the inner cylindrical wall, the inner tube supported within the outer tube, and the inner tube capable of linear translation through the free end of the outer tube;
• the trailing portion of the inner tube having a shoulder extending radially inward and axially defined between a contact end surface and a leading surface of the trailing portion;
• and
• the shuttle having a forward stop member, a mid portion, and a rearward stop member, the mid portion extending between and radially inward of the forward and rearward stop members, the mid portion engaged slideably to the shoulder, the forward stop member contacting the leading surface of the shoulder when the actuator is in a retracting state, the rearward stop member contacting the contact end surface of the shoulder when the actuator is in an extending state.

A method of extending and retracting a knee bolster pad comprising the steps of:

• turning a vehicle ignition switch on;
• performing a pre-impact warning system check;
• performing a knee bolster system check;
• activating the impact pre-sensing warning system;
• activating the knee bolster system;
• initiating search mode to detect extend flag signals from a plurality of sensor outputs;
• checking for an overriding retract flag, if detected, retracting a knee bolster pad if extended regardless of existing extend flags;
• extending a knee bolster pad if no overriding retract flags exist, the knee bolster pad is not already extended, and an extend flag exists caused by any one of the plurality of sensors;
• detecting a retract flag from all of the plurality of sensors;
• and
• retracting the knee bolster pad if extended.