Flexible disk cassette with improved radial shift limitation structure for use in a magnetic recording and/or reproducing apparatus

Abstract

A flexible magnetic disk cassette includes a flexible magnetic disk. A center core disk is also provided having a center hollow and raised fringe, and is attached at a center of the flexible magnetic disk with the raised fringe. A cover having an upper half and lower half for containing the flexible magnetic disk with the center core disk is provided. The lower half of the cover has a driving hole a little larger than an outer diameter of the center hollow of the center core disk.

I claim as my invention: 
     
       1. A flexible magnetic disk cassette comprising: (a) a flexible magnetic disk;   (b) a center core disk .[.having a.]. .Iadd.including an upwardly opening, pan-shaped .Iaddend.center hollow .[.and.]. .Iadd.having a circular peripheral wall from which a .Iaddend.raised fringe .Iadd.extends radially outward.Iaddend., and being attached at a center of said flexible magnetic disk with said raised fringe; and   (c) a cover .[.having.]. .Iadd.including .Iaddend.an upper half and .Iadd.a .Iaddend.lower half .[.containing.]. .Iadd.having confronting inner surfaces between which .Iaddend.said flexible magnetic disk .[.with.]. .Iadd.and .Iaddend.said center core disk .Iadd.are contained.Iaddend., said lower half having a driving hole .[.a little.]. .Iadd.diametrically .Iaddend.larger than an outer diameter of said .Iadd.circular peripheral wall of the .Iaddend.center hollow of said center core disk and .Iadd.being radially engageable at an edge of said driving hole with said circular peripheral wall for locating said magnetic disk within said cover, and said upper half having a ring-shaped projection extending therefrom toward said inner surface of the lower half and said driving hole, said ring-shaped projection having an outer diameter smaller than an inner diameter of said circular peripheral wall of said upwardly opening center hollow and being radially engageable with said circular peripheral wall for locating said magnetic disk within said cover, said circular peripheral wall of the center hollow extending into said driving hole or said projection extending into said center hollow radially inside said circular peripheral wall in all positions of said magnetic disk and center core disk between said upper and lower halves of the cover..Iaddend. .[.2. A flexible magnetic disk cassette as claimed in claim 1; wherein said upper half of said cover is provided with a ring-shaped projection having a diameter a little smaller than an inner diameter of said center hollow of the center core disk..]. .[.3. A flexible magnetic disk cassette as claimed in claim 2; wherein said raised fringe and said ring-shaped projection are so designed as to prevent said flexible magnetic disk from undesirable positioning within said cover when said flexible magnetic disk   
     
     
        is not ready for use..]. 4. A flexible magnetic disk cassette comprising: (a) a flexible magnetic disk;   (b) a pan-shaped one-piece center core disk of magnetic material .[.having a.]. .Iadd.including an upwardly opening .Iaddend.center hollow .[.and.]. .Iadd.having a circular peripheral wall from which a .Iaddend.raised fringe .Iadd.extends radially outward.Iaddend., said center core disk being attached at a center of said flexible magnetic disk by said raised fringe; and   (c) a cassette cover .[.having.]. .Iadd.including .Iaddend.an upper half and .Iadd.a .Iaddend.lower half .[.containing.]. .Iadd.having confronting inner surfaces between which .Iaddend.said flexible magnetic disk .[.with.]. .Iadd.and .Iaddend.said center core disk .Iadd.are contained.Iaddend., said lower half having a driving aperture .Iadd.diametrically .Iaddend.larger than an outer diameter of said .Iadd.circular peripheral wall of the .Iaddend.center hollow of said center core disk .Iadd.and being radially engageable at an edge of said driving aperture with said circular peripheral wall for locating said magnetic disk within said cover, and said upper half having a ring-shaped projection extending therefrom toward said inner surface of the lower half and said driving aperture, said ring-shaped projection having an outer diameter smaller than an inner diameter of said circular peripheral wall of the upwardly opening center hollow and being radially engageable with said circular peripheral wall for locating said magnetic disk within said cover, said circular peripheral wall of the center hollow extending into said driving aperture or said projection extending into said center hollow radially inside said circular peripheral wall in all positions of said magnetic disk and center core disk between said upper and lower halves of   
     
     
        said cover..Iaddend. 5. A magnetic disk cassette comprising: a flexible magnetic disk;   a center core disk attached and positioned in an aperture at a center of the flexible magnetic disk;   the center core disk .[.having.]. .Iadd.being pan-shaped and including .Iaddend.an .Iadd.upwardly opening .Iaddend.annular center hollow .Iadd.having a circular peripheral wall .Iaddend., and   a cover .[.having.]. .Iadd.including .Iaddend.an upper wall and .Iadd.a .Iaddend.lower wall .Iadd.having confronting inner surfaces .Iaddend.between which the flexible magnetic disk is positioned, the upper wall having a ring-like projection .[.receivable.]. .Iadd.received .Iaddend.in the annular hollow of the center core disk when the magnetic disk is assembled in the cover .Iadd.and being radially engageable with said circular peripheral wall of said annular hollow for locating said magnetic disk within said cover.Iaddend., the lower wall having a driving hole for access to the center core disk by a driving mechanism.Iadd., the circular peripheral wall of said annular hollow extending into the driving hole and being radially engageable with said driving hole at an edge thereof for locating said magnetic disk within said cover, and said projection extending from the upper wall toward the inner surface of the lower wall and said driving hole, said circular peripheral wall of the annular hollow extending into said driving hole or said projection extending into said annular hollow radially inside said circular peripheral wall in all positions of said magnetic disk and center core disk between said upper and lower walls of said cover..Iaddend. .[.6. A cassette according to claim 5 wherein the center core disk at least partially extends into the driving hole, the driving hole having a diameter slightly larger than an outer diameter of the annular hollow of   
     
     
        the center core disk..]. 7. A magnetic disk cassette, comprising: a flexible magnetic disk;   a .Iadd.pan-shaped .Iaddend.center core disk .[.having a.]. .Iadd.including an upwardly opening .Iaddend.center hollow .[.and.]. .Iadd.having a circular peripheral wall from which .Iaddend.a ring-like raised fringe .Iadd.extends radially outward.Iaddend., said raised fringe providing an attachment surface means which together with an adhesive attachs the center core disk to the flexible magnetic disk in a central aperture thereof; and   a cover .[.having.]. .Iadd.including .Iaddend.an upper wall and .Iadd.a .Iaddend.lower wall .[.containing the .]. .Iadd.having confronting inner surfaces between which said .Iaddend.flexible magnetic disk .[.with.]. .Iadd.and .Iaddend.the center core disk .Iadd.are contained.Iaddend., the lower wall having a driving hole positioned for permitting access to drive the center core disk from an external driving means.Iadd., said driving hole being diametrically larger than an outer diameter of said circular peripheral wall of the center hollow of said center core disk and being radially engageable at an edge of said driving hole with said circular pripheral wall for locating said magnetic disk within said cover, and said upper wall having a ring-shaped projection extending therefrom toward said inner surface of the lower wall and said driving hole, said projection having an outer diameter smaller than an inner diameter of said circular peripheral wall of the upwardly opening center hollow and being radially engageable with said circular peripheral wall for locating the magnetic disk within said cover, said circular peripheral wall of the center hollow extending into said driving hole and said projection extending into said center hollow radially inside said circular peripheral wall in all positions of said magnetic disk and center core disk between said upper   
     
     
        and lower walls of said cover..Iaddend. 8. A magnetic disk cassette, comprising: a flexible magnetic disk;   a pan-shaped center core disk .[.having a.]. .Iadd.including an upwardly opening .Iaddend.center hollow .[.and.]. .Iadd.having a circular peripheral wall from which a .Iaddend.raised fringe .Iadd.extends radially outward .Iaddend.and being attached to a center of said flexible magnetic disk with said raised fringe;   a cover .[.having.]. .Iadd.including .Iaddend.an upper half and .Iadd.a .Iaddend.lower half .[.containing.]. .Iadd.having confronting inner surfaces between which .Iaddend.said flexible magnetic disk .[.with.]. .Iadd.and .Iaddend.said center core disk .Iadd.are contained.Iaddend., said lower half having a driving hole for access by a driving means to the center core disk;   .Iadd.said upper half having a ring-shaped projection extending therefrom toward said inner surface of the lower half and said driving hole, said driving hole being diametrically larger than an outer diameter of said circular peripheral wall of the center hollow of said center core disk and being radially engageable at an edge of said driving hole with said circular peripheral wall for locating said magnetic disk within said cover, said ring-shaped projection having an outer diameter smaller than an inner diameter of said circular peripheral wall of the upwardly opening center hollow and being radially engageable with said circular peripheral wall for locating said magnetic disk within said cover, said circular peripheral wall of the center hollow extending into said driving hole or said projection extending into said center hollow radially inside said circular peripheral wall in all positions of said magnetic disk and center core disk between said upper and lower halves of said cover;.Iaddend.   first and second disk-like cleaning fabrics positioned between the magnetic disk and the respective upper and lower .[.walls.]. .Iadd.halves.Iaddend.; and   the upper and lower .[.walls.]. .Iadd.halves .Iaddend.and the first and second cleaning fabrics having a magnetic head opening means therein to permit access to a recording surface of the magnetic disk by a magnetic   
     
     
        head. 9. A flexible magnetic disk cassette system, comprising: a cassette formed of a flexible magnetic disk having a pan-shaped center core disk forming .[.a.]. .Iadd.an upwardly opening .Iaddend.center hollow .[.and.]. .Iadd.surrounded by an .Iaddend.outer convex portion and having a raised .[.flange.]. .Iadd.fringe .Iaddend.upwardly of a lower surface of the center core disk .Iadd.and extending radially outward from said outer convex portion.Iaddend., the center core disk being attached at a center of the flexible magnetic disk with said raised fringe, and a cover .[.having.]. .Iadd.including .Iaddend.an upper wall and a lower wall .[.containing.]. .Iadd.having confronting inner surfaces between which .Iaddend.the flexible magnetic disk .Iadd.is contained, .Iaddend.the lower wall having a driving hole .Iadd.diametrically larger than an outer diameter of said outer convex portion and being radially engageable at an edge of said driving hole with said outer convex portion for locating said magnetic disk within said cover, said driving hole being .Iaddend.aligned with the center core disk, said center core disk having a central positioning aperture and an offset driving aperture;   .Iadd.said upper wall having a ring-shaped projection extending therefrom toward said inner surface of the lower wall and said driving hole, said ring-shaped projection having an outer diameter smaller than an inner diameter of said outer convex portion surrounding the upwardly opening center hollow and being radially engageable with said outer convex portion for locating said magnetic disk within said cover, said outer convex portion extending into said driving hole or said projection extending into said center hollow radially inside said outer convex portion in all positions of said magnetic disk and center core disk between said upper and lower halves of the cover; .Iaddend.and .[.a.]. driving and recording/reproducing system means for receiving the cassette, said system   
     
     
        means having driving means engageable with the center core disk. .[.10.  A system according to claim 9; wherein a ring-like projection extends from an inside surface of the upper wall of the cassette cover and is 
     
     
        engageable in a center hollow of the center core disk..]. 11. A flexible magnetic disk cassette driving apparatus for rotating a flexible magnetic disk having a center core and positioned within .[.the.]. .Iadd.a .Iaddend.cassette .Iadd.housing having upper and lower walls between which said disk is contained.Iaddend., comprising: driving means coupled with the center core of the flexible magnetic disk for rotating it at a predetermined speed;   cassette supporting means mounted on a chassis for receiving and .[.positioning.]. .Iadd.supporting .Iaddend.said .[.flexible magnetic disk.]. cassette .Iadd.housing at said lower wall; .Iaddend.   cassette pressing means .Iadd.bearing against said upper wall .Iaddend.for depressing said cassette .Iadd.housing .Iaddend.on said cassette supporting means; and   .[.positioning.]. means on said driving means for .[.positioning.]. .Iadd.engaging .Iaddend.an inner surface of .[.an.]. .Iadd.said .Iaddend.upper wall of said disk cassette .Iadd.housing and positioning said upper wall in a substantially flat plane relative to an inner surface   
     
     
        of said lower wall thereof..Iaddend. 12. The driving apparatus of claim 11 wherein the cassette supporting means comprises a plurality of spring biased members pressing down on the upper wall of the cassette at outer 
     
     
        regions thereof. 13. A driving apparatus according to claim 11 wherein said .[.positioning.]. means for .[.positioning.]. .Iadd.engaging .Iaddend.the inner surface of the upper wall of the disk cassette .Iadd.housing .Iaddend.comprises an end .Iadd.surface .Iaddend.of a center positioning pin positioned within a central aperture of the central 
     
     
        core.Iadd., said end surface being positioned in said plane..Iaddend. 14. The apparatus of claim 13 wherein the center positioning pin has a 
     
     
        hemispherical top surface. 15. A flexible magnetic disk cassette system comprising: a disk cassette formed of a flexible magnetic disk positioned within a cover having upper and lower walls closely spaced to the flexible magnetic disk, said flexible magnetic disk having a central aperture with a corresponding aperture in the lower wall of the disk cassette;   a drive mechanism for receiving the disk cassette thereon and having a pin associated therewith which is positioned through the aperture of the lower wall of the cassette and through the aperture of the magnetic disk; and   an end of the pin abutting against an inner surface of the upper wall of the cassette when the cassette is in position on the driving apparatus so as to insure a given position of the upper wall relative to the lower wall so as to prevent any undesired warping contact of the inner surfaces of   
     
     
        the upper and lower walls with the flexible magnetic disk. 16. A system according to claim 14 wherein biasing means are provided so as to press downwardly at outer peripheral edges of the cassette when it is in 
     
     
        position on the driving apparatus. 17. The system of claim 16 wherein structural elements are provided in the cassette disk such that when the outer peripheral biasing members are pressing down and the center pin presses up at the inner surface of the upper wall, the upper wall becomes substantially flat and the lower wall becomes substantially flat so as to prevent any warping contact between the upper and lower walls and the 
     
     
        flexible magnetic disk. 18. A magnetic disk cassette, comprising: a flexible magnetic disk;   a cover .[.having.]. .Iadd.including .Iaddend.upper and lower walls .Iadd.having confronting inner surfaces .Iaddend.between which the flexible magnetic disk is positioned, said lower wall having a driving hole .[.means.]. therein through which the flexible disk .[.may be.]. .Iadd.is .Iaddend.driven;   a pan-shaped center-core disk having magnetic material therein and forming .[.a.]. .Iadd.an upwardly opening .Iaddend.center hollow .[.and.]. .Iadd.surrounded by an .Iaddend.outer convex portion at a central portion of the magnetic disk and having in a lower surface of the pan-shaped disk a center aperture .[.means.]. for receiving a center positioning pin and a driving aperture .[.means.]. for receiving a .Iadd.spring biased .Iaddend.driving pin of .[.said.]. .Iadd.a .Iaddend.drive device;   .Iadd.said upper wall having a ring-shaped projection extending therefrom toward said inner surface of the lower wall and said driving hole, both said driving hole at an edge thereof and said projection being radially engageable with said outer convex portion for locating said magnetic disk within said cover, said center hollow extending into said driving hole or said projection extending into said center hollow radially inside said outer convex portion in all positions of said magnetic disk between said upper and lower walls of the cover; .Iaddend.and   the center aperture .[.means.]. being .[.slightly.]. offset from a center point of the flexible magnetic disk and being .[.designed slightly.]. larger than the center positioning pin such that when the spring biased driving pin engages an edge of the driving aperture .[.means.]. the center positioning pin of the drive device abuts against an edge of the center aperture .[.means.]. and a central axis of the center positioning pin will   
     
     
        lie on the center point of the magnetic disk. 19. A .[.magnetic.]. .Iadd.flexible .Iaddend.disk cassette .Iadd.for use in a magnetic recording and reproducing apparatus.Iaddend., comprising: a flexible disk;   a cover .[.having.]. .Iadd.including .Iaddend.upper and lower walls .Iadd.having confronting inner surfaces .Iaddend.between which the flexible disk is positioned, said lower wall having a driving hole .[.means.]. therein through which the flexible disk .[.may be.]. .Iadd.is .Iaddend.driven .Iadd.and said upper wall having a ring-like projection extending therefrom toward said inner surface of said lower wall and said driving hole; and .Iaddend.   a pan-shaped center-core disk of magnetic material .[.is.]. positioned centrally on the .[.magnetic.]. .Iadd.flexible .Iaddend.disk and .[.has.]. .Iadd.having .Iaddend.an outer convex portion .Iadd.at a central portion .Iaddend.receivable in and .Iadd.of .Iaddend.a diameter .[.slightly.]. smaller than .Iadd.an inner diameter of .Iaddend.said driving hole .[.means.]. in the lower wall and .[.a.]. .Iadd.an upwardly opening .Iaddend.center hollow having an inner diameter .[.slightly.]. larger than .[.a.]. .Iadd.an outer .Iaddend.diameter of .[.a.]. .Iadd.said ep projection from said upper wall .[.receivable within said center hollow.]..Iadd., both said driving hole at an edge thereof and said projection being radially engageable with said outer convex portion for locating said flexible disk within said cover, said outer convex portion extending into said driving hole or said projection extending into said center hollow radially inside said outer convex portion in all positions of said flexible disk and center-core disk between said upper and lower   
     
     
        walls of said cover. 20. A .Iadd.flexible disk .Iaddend.cassette according to claim 19 wherein the pan-shaped center-core disk constructed of magnetic material is mounted on a central aperture of the flexible 
     
     
        .[.magnetic.]. disk. 21. A .Iadd.flexible disk .Iaddend.cassette according to claim 19 wherein the center-core disk has a raised fringe at which it 
     
     
        is attached to the flexible .[.magnetic.]. disk. 22. A .[.magnetic.]. .Iadd.flexible .Iaddend.disk cassette according to claim 19 wherein the projection at the upper wall is circular and in the form of an annular 
     
     
        ring. 23. A .[.magnetic.]. .Iadd.flexible .Iaddend.disk cassette .Iadd.for use in a magnetic recording and reproducing apparatus.Iaddend., comprising: a flexible disk;   a cover .[.having.]. .Iadd.including .Iaddend.upper and lower walls .Iadd.having confronting inner surfaces .Iaddend.between which the flexible disk is positioned, said lower wall having a driving hole .[.means.]. therein through which the flexible disk .[.may be.]. .Iadd.is .Iaddend.driven .Iadd.and said upper wall having a ring-like projection extending therefrom toward said inner surface of said lower wall and said driving hole.Iaddend.; and   a pan-shaped center-core disk .[.having a.]. .Iadd.including an upwardly opening .Iaddend.hollow central portion .Iadd.having a circular peripheral wall .Iaddend.which receives .[.a.]. .Iadd.said .Iaddend.projection from said upper wall, said pan-shaped center-core disk being provided at a central portion of the .[.magnetic.]. .Iadd.flexible .Iaddend.disk.Iadd.;   both said driving hole at an edge thereof and said projection being radially engageable with said circular peripheral wall for locating said flexible disk within said cover;   said circular peripheral wall of the portion extending into said driving hole or said projection extending into said hollow central portion radially inside said circular peripheral wall in all positions of said flexible disk and said center-core disk between said upper and lower walls   
     
     
        of said cover. .Iaddend. 24. A cassette according to claim 23 wherein the pan-shaped center-core disk is of a magnetic material, has a raised fringe relative to a lower surface, and the .[.magnetic.]. .Iadd.flexible .Iaddend.disk has an aperture within which the pan-shaped center-core disk is positioned .[.therein.]., and the .[.magnetic.]. .Iadd.flexible .Iaddend.disk .[.attaching.]. .Iadd.is attached .Iaddend.to the center-core disk at said fringe by adhesive. .Iadd.25. A cassette according to claim 24; wherein said flexible disk is magnetic..Iaddend. .Iadd.26. A cassette according to claim 24; wherein said projection from the upper wall is circular and in the form of an annular ring having an outer diameter slightly smaller than an inner diameter of said hollow central portion..Iaddend. .Iadd.27. A flexible disk cassette according to claim 19; wherein said flexible disk is magnetic..Iaddend.