Roller assembly for an electroplating apparatus

A roller assembly for conveying a sheet-shaped workpiece in an electroplating apparatus in a predetermined direction, the workpiece having a hypothetical middle line that extends along the predetermined direction, said roller assembly comprising:

• a feeding mechanism including
• a plurality of feeding rollers,
• a first threaded rod disposed parallel to said feeding rollers and having a left-hand thread portion and a right-hand thread portion, which are adapted to be disposed symmetrical along the middle line of the workpiece,
• two first guiding members formed respectively with a pair of threaded holes that engage respectively said left-hand and right-hand thread portions of said first threaded rod so as to move said first guiding members in opposite directions on said first threaded rod when said first threaded rod rotates, said first guiding members being adapted to abut against two opposite sides of the workpiece, thereby guiding the workpiece to move in the predetermined direction, and
• a first driving unit for rotating said first threaded rod;
• a conducting mechanism including
• a second threaded rod disposed parallel to said first threaded rod and having a left-hand thread portion and a right-hand thread portion, which are adapted to be disposed symmetrical along the middle line of the workpiece,
• two second guiding members formed respectively with a pair of threaded holes that engage respectively said left-hand and right-hand thread portions of said second threaded rod so as to move said second guiding members in opposite directions on said second threaded rod when said second threaded rod rotates, said second guiding members being adapted to abut against the sides of the workpiece, thereby guiding the workpiece to move in the predetermined direction,
• a second driving unit for rotating said second threaded rod, and
• two conducting units attached respectively to said second guiding members and adapted to supply electric current to the sides of the workpiece, respectively;
• a controller connected electrically to said first and second driving units so as to activate said first and second driving units simultaneously, thereby permitting synchronous rotation of said first and second threaded rods;
• and
• a position sensing unit connected electrically to said controller and adapted to detect width of the workpiece so as to activate said controller such that said first and second driving units move said first and second guiding members relative to said first and second threaded rods until a distance between said first guiding members and a distance between said second guiding members are equal to the width of the workpiece.