Magnetic disk cartridge

DETAILED DESCRIPTION The primary object of the present invention is to provide a magnetic disk cartridge which is small and thin in size and which can be assembled with high efficiency.
Another object of the present invention is to provide a magnetic disk cartridge which provides secure shutter operations.
The present invention provides a magnetic disk cartridge having a case and a magnetic disk rotatably housed in the case, the magnetic disk cartridge comprising: (i) a shutter for opening and closing window sections provided in said case for insertion of a magnetic head for recording, said shutter being fitted on outer wall surfaces of said case in a manner slidable in a direction approximately normal to the depth direction of apertures of said window sections, (ii) a spring for always urging said shutter to close said window sections, the ends of said spring being engaged with a part of said case and with a part of said shutter, and (iii) an engagement means for engaging at least one end of said spring with said case or said shutter via an engagement member.
In the present invention, the engagement member is formed into a block-like shape, for example into a cubical shape, and secured to at least one end of the spring.
On the upper and lower surfaces of the engagement member are provided cylindrical engagement protrusions positioned vertically and symmetrically.
The engagement protrusions are fitted into and supported by engagement groove sections which are fabricated integrally with the case or with the shutter and which can be deformed resiliently.
Accordingly, after the protrusions of the engagement member secured to one end of the spring is fitted into and supported by the engagement groove sections at the step of fitting the shutter onto the case, the spring can not separate from the case or from the shutter.
Then, the other end of the spring is engaged with a hook of the shutter or the case, and the shutter is fitted onto the case.
Therefore, in the present invention, the efficiency of the assembly work is improved, and it is possible to obtain secure operations of the shutter