Constant force windup spring web threading system

摘要

An automatic threading apparatus for a magnetic tape transport is disclosed using a constant force spring located outside of the plane of the tape path. A leader block attached to the free end of the tape from a cartridge is connected to a pick-up pin of the threading apparatus. The pick-up pin is attached to a spool that is connected to a constant force spring, sometimes known as a negator spring. The other end of the spring is connected to a hub which is located on a plane different from the take-up reel. A latch holds the spool with the spring adjacent to the supply reel. When the latch releases the spool, the spring on the spool will wind around the spool and pull the pick-up pin through a guide path such that the leader block is placed into the take-up spool and forms a part of the take-up hub to allow a desired smooth surface for the wraps of the tape around the hub.