Power seat driving apparatus for a vehicle

A power seat driving apparatus for a vehicle, comprising:

• a seat section;
• an electric motor mounted in said seat section;
• a plurality of operating threaded shafts having a locking section which are rotated by said electric motor;
• and
• a plurality of nut members which are connected to said seat section, each nut member threadably received on an operating threaded shaft of said plurality of operating threaded shafts, the power seat driving apparatus being structured to move said seat section back and forth relative to said plurality of operating threaded shafts by a movement of at least one said nut member, each said nut member driven by said operating threaded shaft to which it is mounted by the normal or reverse rotation of said electric motor, at least two additional nut members being mounted to at least one of said plurality of operating threaded shafts to selectively achieve a different adjustment of said seat section from the adjustment of a forward and backward position of said seat section by the movement of said at least two additional nut members relative to said at least one operating threaded shaft to which it is mounted, all said nut members cooperating with said operating threaded shaft to which it is mounted and on whose circumference said locking section is formed, each said nut member having:
• a casing through which said operating threaded shaft to which said nut member is mounted passes;
• a nut body which is housed in said casing and which is threadably and rotatably supported by said operating threaded shaft to which said nut member is mounted in the axial dimension thereof;
• a first clutch body through which said operating threaded shaft to which said nut member is mounted passes, said first clutch body being non-rotatably but axially movable with respect to said nut body and which is provided on one side of said nut body so that said clutch body is capable of being engaged with said one side of said nut body;
• a second clutch body through which said operating threaded shaft to which said nut member is mounted passes, said second clutch body engaged with said locking section of said operating threaded shaft to which said nut member is mounted so as to rotate together with said operating threaded shaft to which said nut member is mounted, is capable of being engaged with a second side of said nut body and which is further capable of moving axially relative to said nut body;
• a connecting lever which supportedly connects said first and second clutch bodies which are located facing each other on opposite ends of said nut body, said connecting lever having an interval which makes one clutch body disengage from said nut body when the other clutch body is engaged with said nut body;
• and
• a clutch operating means for switching said first and second clutch bodies between a first shift condition where said first clutch body is engaged with said nut body and a second shift condition where said second clutch body is engaged with said nut body.