Tanker access platform

A height adjustable tanker access platform system having a fixed frame member, an access platform operatively mounted on said fixed frame member for vertical movement with respect to said fixed frame member, and a drive mechanism operatively engaged between said fixed frame member and said access platform so as to provide means for raising and lowering said access platform, said drive mechanism comprising:

• a drive means securely mounted on a selected one of said fixed frame member and said access platform;
• a drive pulley operatively connected to said drive means to permit selective driven rotation of said drive pulley about a first rotational axis;
• a main idler pulley rotatably mounted on the other of said fixed frame member and said access platform for rotation about a second rotational axis;
• and
• a first drive cable securely attached at an anchored end to said fixed frame member and securely attached at an opposite remote end to a vertically movable counter-weight, said first drive cable being looped around said main idler pulley and looped in drivable engagement around said drive pulley such that rotation of said drive pulley causes corresponding movement of said first drive cable, so as to thereby cause said access platform to be vertically moved with respect to said fixed frame member;
• wherein said drive pulley has a first "V"-shaped groove disposed around the periphery thereof, wherein said first "V"-shaped groove forms an angle of between about 40.degree. and about 70.degree. so as to receive said first drive cable in releasable binding relation therein.