Tape cassette storage and accessing system with closely spaced layered cassettes

This invention relates to magnetic tape storage and accessing systems for tape libraries, for example, or for backup storage of digital information. A compact tape cassette or cartridge storage and accessing system includes a longitudinally extending frame with two endless link chains, one on each side of the frame; and cassette carriers are mounted in two layers by linkages to the chains, with one layer moving forward and the other to the rear. At the ends, a cam follower on each cassette carrier, and a control groove, and associate guide and latch members, tilt the cassette carriers to smoothly shift them from one layer to the other. With 8 mm tape cassettes, the height of the system is within 1¾ inches, for compatibility with standard electrical equipment racks.