Disk cartridge with a stop wall to engage a shutter plate projection and at least one support located between the stop wall and a cartridge side edge

A case of a cartridge for accommodating a disk therein and comprising:

• upper and lower shell halves assembled with each other, the lower shell half being provided with a head insertion hole for inserting a reading/writing head and a spindle insertion hole for inserting a spindle for rotating the disk, the upper shell half being provided with a head insertion hole, and a shutter having a long main closing plate for opening and closing the head and spindle insertion holes of the lower shell half and a short supplementary closing plate for opening and closing the head insertion hole of the upper shell half when the shutter slidably moves on the case and a base portion formed between the two closing plates of the shutter to engage with a guide portion provided on a front end of the case for slidably guiding the shutter, the main closing plate being slightly narrower in width than that of the supplementary closing plate so that a projection is formed adjacent the base portion of the shutter as part of the main closing plate on a front side of the shutter when the shutter is moved to open the insertion holes of the case, the lower shell half being provided with four support seat places formed separately in its side periphery to place the cartridge on four support pins provided in a disk player when the cartridge is loaded in the disk player, each of said support seat places being a small smooth area to be supported on respective said support pin, the upper and lower shell halves being provided with two shallow recesses, respectively, for slidably receiving each closing plate and two stopping walls, respectively, at peripheries of a side of the case for stopping a side of each closing plate when the shutter is moved to open the insertion holes, a cut away portion being provided at a front end of the case along a stopping wall on the lower shell half to engage with the projection formed on the main closing plate when the shutter is moved completely to open the insertion holes, one of the support seat places being formed between a side edge of the lower shell half and the stopping wall.