Abstract: A capstan driven web system having a take-up reel and a supply reel, the tape being drawn from the supply reel by a tape driven capstan arrangement. The drawn tape is collected on the take-up reel which is mechanically coupled to the supply reel by a mechanism having variable transfer ratio. In one embodiment, the variable ratio transport system is formed of a belt drive system having variable diameter pulleys coupled to each of the tape reels. The transfer ratio of the variable diameter pulley system is controlled by a servo mechanism which selects an appropriate transfer ratio in response to the position of a servo arm which senses the tension of the tape.

Abstract: A mechanism by which more than one torsion spring can be serially coupled to a member to impart a torque thereto equivalent to that from a single spring having the same number of turns as the total turns of the coupled springs. The springs to be coupled are connected at one end to respective storage shafts which are mounted to a free floating coupling arm. The coupling arm rotates about a shaft coaxial with the member to which the other ends of the springs are attached. In a capstan driven web system having a take-up reel and a supply reel, two sets of serially coupled negator springs are utilized to maintain proper web tension during driving of the web system.