Tape casette loading system compatible with two different sized cassettes

A tape loading mechanism of a magnetic recording/reproducing apparatus for recording and/or reproducing an information signal on and from a magnetic tape contained in one of first and second tape cassettes which is held at a respective one of first and second predetermined positions in a body of the magnetic recording/reproducing apparatus, for loading and unloading the magnetic tape on a rotary drum means of the magnetic recording and reproducing apparatus on which magnetic heads for recording and reproduction of the infraction are carried, comprising:

• a chassis fixed on the body of the magnetic recording/reproducing apparatus such that said first tape cassette having a first size and held at said first predetermined position in the body of the magnetic recording/reproducing apparatus is positioned above a first predetermined area defined on the chassis and that said second tape cassette having a second size substantially smaller than said first size and held at said second predetermined position in the body of the magnetic recording/reproducing apparatus is positioned above a second predetermined area of the chassis included in said first predetermined area, said chassis further carrying said rotary drum means at a position outside said first predetermined area;
• first and second arcuate guide grooves respectively provided on said chassis with the rotary drum means being located therebetween, each of said arcuate guide grooves comprising a first part located outside said first predetermined area first predetermined area and said, a second part located inside said first predetermined area but outside said second predetermined area, and a third part located inside said first predetermined area and said second predetermined area;
• first and second loading members respectively held on said chassis in a manner movable along said first and second arcuate guide grooves, each of said loading members carrying an oblique pole adapted to carry the magnetic tape and to wrap it around the rotary drum means when the loading members are located at respective first positions in said first parts of said first and second guide grooves, respectively said oblique poles on the loading members being accepted in a depressed part at a front side of the first tape cassette which faces the rotary drum means when the first tape cassette is held at the first predetermined position in the body of a magnetic recording/reproducing apparatus and said first and second loading members are respectively located at second positions in said second parts of said first and second guide grooves, and said oblique poles on the loading members being accepted in a depressed part at a front side of the second tape cassette which faces the rotary drum means when the second tape cassette is held at the second predetermined position in the body of the magnetic recording/reproducing apparatus and said first and second loading members are respectively located at third positions in siad third parts of said first and second guide grooves;
• and
• a motor driving means comprising a motor for moving said first and second loading members along said first and second guide grooves respectively between said first, second and third positions.