Patent ID: 6860445

Claim:
A magnetic tape cartridge comprising a cartridge casing formed by upper and lower casing halves connected together, and a single reel around which a magnetic tape with a leader pin fixed to the leading end thereof is wound and which is contained in the cartridge casing for rotation, the leader pin being removably held in a tape draw-out opening with the axial direction of the leader pin directed in the vertical direction under urging force of a spring member acting on upper and lower end portions of the leader pin sideways with the upper and lower end portions received in recesses respectively formed in the upper and lower casing halves, wherein the improvement comprises that the spring member comprises a base portion which is mounted on the inner surface of the upper or lower casing half of the cartridge casing and an arm portion which extends from the base portion and can be deflected to removably hold the upper or lower end portion of the leader pin, and the edge of the arm portion opposed to the inner surface of the cartridge casing is provided with a cutaway portion for preventing the arm portion from being brought into contact with the inner surface of the cartridge casing.