Powered sliding device for vehicle slide door

1. A powered sliding device engaged to a vehicle slide door including a wire cable coupled to the slide door which is slidably mounted on a vehicle body in a forward door opening direction and a rearward door closing direction, the powered sliding device sliding the slide door in the door opening direction and the door closing direction by moving the wire cable with a motor power of a power unit, comprising:

a lower rail provided in the vicinity of a lower part of an ingress/egress aperture of the vehicle body, said lower rail being protected from rainwater from an outside of the vehicle body when the slide door is closed;

a lower bracket provided to the slide door and slidably engaged with the lower rail;

a center rail provided at a quarter panel of the vehicle body, said center rail being exposed to rainwater when the slide door is closed;

a center bracket provided to the slide door and slidably engaged with the center rail;

said power unit being provided in an inside space of the slide door;

said wire cable including a door opening cable and a door closing cable, each of base side ends of the door opening cable and the door closing cable being coupled to the power unit;

a distal end of the door opening cable being protruded outside the slide door from a position in the vicinity of the lower bracket of the slide door, extended in a rearward direction within the lower rail by way of a front side of a lower pulley of the lower bracket, and fixed to the vehicle body in the vicinity of a rear end of the lower rail;

a distal end of the door closing cable being protruded outside the slide door from a position in the vicinity of the center bracket of the slide door, extended in a forward direction within the center rail by way of a rear side of a center pulley of the center bracket, and fixed to the vehicle body in the vicinity of a front end of the center rail;

wherein when said center bracket is relatively rotated with respect to the slide door due to a shape of the center rail during the sliding movement of the slide door, said center pulley is relatively displaced in a certain amount by the rotation of the center bracket with respect to the slide door, but said center pulley is not displaced any further than the certain amount by the rotation of the center bracket.

2. The powered sliding device for the vehicle slide door according to claim 1 , further comprising a swinging arm pivotally mounted on the slide door with a vertical supporting shaft, said center pulley being pivotally mounted on a rotating side end of the swinging arm with a pin to bias the swinging arm in a predetermined direction by a pressure from the door closing cable, a bent part provided on the center bracket, said swinging arm being brought into contact with the bent part by being biased in the predetermined direction, a pressing part provided on the slide door for abutting against the swinging arm to restrict the rotation of the swinging arm when the center bracket is rotated over the certain amount with respect to the slide door.