Computed tomography system cable retractor

X-ray apparatus having improved means for guiding cables running between stationary parts and electrical devices on rotating parts, comprising:

• support means,
• a base having an opening and being mounted on the support means for rotation about a nominally horizontal axis extending through the opening,
• said electrical devices including X-ray source means mounted to the base on one side of said axis and X-ray detector means mounted to the base on the other side of said axis for jointly rotating about a space for being occupied by an X-ray examination subject,
• inner axially extending drum means fastened to said base for rotation therewith and having a radially outwardly presented peripheral surface concentric to and radially spaced from said axis, said drum means having an opening for cables to pass through,
• outer axially extending fixedly mounted drum means having a radially inwardly presented peripheral surface radially spaced from and concentric to said surface on said inner drum means to define a circular channel therewith, said second drum means having an opening for cables to pass through,
• a group of cables and means fastening said group near said opening in the fixedly mounted outer drum means and near said opening in the rotatable inner drum means, said cables in the group having sufficient length to form a loop that moves angularly in said channel when said inner drum is being rotated,
• disk means presented toward said channel and means mounting said disk means for rotation independently of said inner drum means,
• a plurality of pulleys mounted to said disk means for rotation about parallel axes extending into said channel, the pulleys being angularly spaced and one of the pulleys being disposed in said cable loop and other of the pulleys being disposed between portions of the cable extending away from the loop,
• means for driving said base and said inner drum thereon rotationally and means for simultaneously driving said disk means rotationally for the angular motion of the disk to be the required fraction of the angular motion of the inner drum that results in said pulleys having an angular motion corresponding to the angular motion of the loop in the cables.