초록 ▼

A disc cartridge is made up of an upper cartridge part and a lower cartridge part for housing a disc-shaped recording medium, such as an optical disc or a magneto-optical disc. At least one of the upper cartridge part and the lower cartridge part has a head-accessing aperture for exposing at least a

A disc cartridge is made up of an upper cartridge part and a lower cartridge part for housing a disc-shaped recording medium, such as an optical disc or a magneto-optical disc. At least one of the upper cartridge part and the lower cartridge part has a head-accessing aperture for exposing at least a portion of the disc-shaped recording medium to the outside. Apparatus for making the disc cartridge includes a first die having a protrusion for forming the head-accessing aperture. The first die defines a cavity on an upper surface of the upper or lower cartridge part, a second die defines a cavity on the inner surface of the upper or lower cartridge part, and an insert die is formed separately from and united to the second die. The insert die has an extension for forming an end face on the inner surface of the upper or lower cartridge part and a protrusion from the extension for abulting the protrusion of the first die during die closure for forming the head-accessing aperture in the upper or lower cartridge part. The second die has at its end portion connected to the insert die a protrusion extending towards the first die. The second die is connected to the insert die with an end face of the extension of the insert die being protruded further towards the first die than the end face of the protrusion of the second die.

대표청구항 ▼

A method of injection molding a disc cartridge having an upper cartridge part and a lower cartridge part and a disc-shaped recording medium rotatably housed within a space defined by the upper cartridge part and the lower cartridge part, at least one of the upper cartridge part and the lower cartrid

A method of injection molding a disc cartridge having an upper cartridge part and a lower cartridge part and a disc-shaped recording medium rotatably housed within a space defined by the upper cartridge part and the lower cartridge part, at least one of the upper cartridge part and the lower cartridge part having a head-accessing aperture for exposing at least a portion of said disc-shaped recording medium to outside, said method comprising the steps of: forming the upper cartridge part or the lower cartridge part having said head-accessing aperture using a molding apparatus having a first die having a first protrusion for forming said head-accessing aperture, said first die defining a cavity on an upper surface of the upper or lower cartridge part, a second die for forming a cavity on the inner surface of the upper or lower cartridge part, and an insert die formed separately from and united to the second die, said insert die having an extension for forming an end face on an inner surface of the upper or lower cartridge part and a second protrusion from said extension for abutting the first protrusion of said first die during die closure for forming said head-accessing aperture in said upper or lower cartridge part, said second die having an end portion thereof connected to said insert die, said end portion having a third protrusion extending towards said first die, said second die being connected to said insert die so that an end face of a first die side of said extension of said insert die is protruded further towards said first die than an end face of the third protrusion of said second die, whereby said first second and third protrusions cooperate during injection molding to prevent burrs being formed on the upper and lower cartridge parts; and combining said upper cartridge part and said lower cartridge part with said disc-shaped recording medium in between, thereby forming said disc cartridge.