Patent ID: 7360291

Claim:
A method of manufacturing a recording tape cartridge having a locking mechanism locking a reel which is accommodated in a case and on which a recording tape is wound, the method comprising the steps of: a. forming gear teeth at an inner side of a floor portion of a reel hub of the reel; b. forming an engaging projection at a surface of the case which surface opposes the floor portion of the reel hub; c. forming a braking member having a disc, and a braking gear, which is annular and which can mesh with the gear teeth, is provided at one surface of the disc, and a groove wall portion, which demarcates an insertion groove into which the engaging projection enters, stands erect at the disc, and the braking member can approach and move away from the floor portion of the reel hub within the case; and d. combining the braking member and the reel within the case; wherein the engaging projection includes projecting pieces which enter through-holes formed in the braking member when the braking member moves away from the floor portion of the reel hub within the case.