Modular library system with stationary and mobile racks for storage of computer catridges

A modular library system for computer cartridges comprising:

• A) a plurality of stationary racks disposed side by side;
• and
• B) at least one mobile rack coupled to and movable with respect to said stationary racks;
• C) each of said stationary and mobile racks comprising
• 1) a plurality of "T" shaped vertical supports, each said vertical support being of integral, one-piece construction, and having a generally planar central element including a front bend, and first and second rear wall elements connected orthogonally to said central element at respective first and second locations distal to said front bend, said central element forming a double-thick, rigid, vertical partition wall, said partition walls of said "T" shaped supports forming a plurality of vertical spaces for receiving a plurality of cartridge-holding trays, and having a plurality of tray-supporting tabs to retain said cartridge-holding trays;
• 2) a top panel interconnecting said "T" shaped supports proximate a top end of said supports;
• 3) a mounting base interconnecting said "T" shaped supports proximate a bottom end of said supports, said mounting base including an outer box, and a plurality of bracing elements disposed within said outer box and extending in a direction parallel to said central elements and attached to said central elements;
• and
• 4) means for maintaining said "T" shaped supports generally parallel with one another, including a spreader for interconnecting said central elements proximate said central bends thereof and intermediate said top panel and said mounting base, and a planar, strip-like rear panel attached to said rear wall elements of said "T" shaped supports intermediate said top panel and said mounting base.