Sunroof mechanism and a rail assembly for the same

A sunroof mechanism for a vehicle having a roof and an opening therein, the sunroof mechanism comprising:

• a pair of track members constructed to be mounted to the roof at side edge portions of the opening, each of the track members having an elongated drive member receiving channel with a longitudinally extending opening;
• a sunroof panel assembly of a size to close the opening, the panel assembly being movably received on the track assembly and moveable with respect to the opening in the roof between an open position, wherein the panel member uncovers the opening and a closed position, wherein the panel member substantially closes the opening in the roof;
• a rail assembly coupled to the pair of track members at end portions thereof and extending therebetween;
• a pair of elongated flexible drive members each coupled to the rail assembly and each extending to the drive member receiving channels, each of the drive members having an end portion thereof connected to portions of the sunroof panel assembly extending through the longitudinally extending openings of the channels;
• a pair of tubular flexible guide sheaths having internal diameters essentially corresponding to external diameters of the drive members, the drive members being received within the sheaths such that the sheaths guide the drive members for axial movement therein;
• the drive member receiving channels also having internal diameters essentially corresponding to the external diameters of the drive members, the drive members being received within the channels such that the channels guide the drive members for axial movement therein;
• and
• a driving unit coupled to the rail assembly and operatively connected to each of the pair of flexible drive members such that operation of the driving unit drives the flexible drive members axially within the guide sheaths and the drive member receiving channels to move the sunroof panel in an opening direction towards the open position and in a closing direction towards the closed position;
• the rail assembly comprising a plurality of mounting portions defining sheath receiving pathways, the guide sheaths being received within the sheath receiving pathways so as to mount the sheaths and the driving members therein to the rail assembly;
• the track members each also including guide sheath receiving portions each open at one end to the drive member receiving channels and at an opposite end to the rail assembly, the guide sheath receiving portions being oversized relative to the channels,
• the guide sheaths having end portions thereof received in the guide sheath receiving portions in axially spaced relation from the drive member receiving channels, the axially spaced relation enabling the guide sheaths to elongate axially due to thermal expansion.