retrator de cinto para o sistema de cinto de segurança e um método de montagem de um retrator de cinto

A belt retractor includes a retractor frame (10) having first and second end faces (10a, 10b) between which a belt reel (12) is pivoted. The belt retractor further includes a belt tensioner and a spring cassette (30) having a helical spring (26) coupled to the belt reel (12). The spring cassette (30) is arranged between the first end face (10a) of the retractor frame (10) and at least one component of the belt tensioner. A method of fitting such belt retractor includes mounting the spring cassette (30) on a component of the belt tensioner, especially on an inside of a tensioner casing (22) and mounting the belt tensioner including the spring cassette (30) on the retractor frame (10), especially on an end wall (10a) of the retractor frame (10). An alternative fitting method includes mounting the spring cassette (30) on an end wall (10a) of the retractor frame (10) and attaching the belt tensioner to the spring cassette (30) mounted on the end wall (10a) of the retractor frame (10).