High speed bidirectional magnetic tape transport with constant tension

Abstract

A length of magnetic tape extending between a pair of reels within a cartridge is driven bidirectionally at high speeds with substantially constant tension by a transport having a pair of capstans engaging and movable to accommodate the constantly changing tape packs on the reels. Constant tape tension is achieved by a driving arrangement utilizing pairs of pulleys of slightly different diameter coupled via overriding unidirectional clutches to shafts which mount the capstans and are driven from a common motor by belts coupled to the different pairs of pulleys. The difference in pulley diameter causes the capstan engaging the takeup reel to be driven slightly faster than the capstan engaging the supply reel so as to maintain the constant tape tension. The tape cartridge has a single front door which is automatically raised upon insertion of the cartridge into the transport by opposite bosses on the transport which engage camming levers at the opposite ends of the front door. The cartridge also includes spring-loaded arrangements for blocking out rotation of the reels except when the cartridge is inserted in the transport, and dust covers which are movable out of the way by movement of the capstan shafts into slots in the cartridge. A camming arrangement resiliently engages the bottom of the cartridge to force the installed cartridge into engagement with three different height referencing elements. A separate locking arrangement engages an aperture in the bottom of the cartridge to lock the installed cartridge in a desired horizontal position until the camming arrangement releases the cartridge.