Winding – tensioning – or guiding – Unwinding and rewinding a machine convertible information... – Cartridge system
Reexamination Certificate
2003-01-03
2004-03-30
Nguyen, John Q. (Department: 3654)
Winding, tensioning, or guiding
Unwinding and rewinding a machine convertible information...
Cartridge system
C360S132000
Reexamination Certificate
active
06712303
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a magnetic tape cartridge, and more particularly to a structure of a sliding door for opening and closing an opening for accommodating a leader pin and a structure for urging the sliding door in a magnetic tape cartridge comprising a cartridge casing, a single reel which is housed in the cartridge casing for rotation and around which a magnetic tape is wound, and the leader pin which is fixed to the leading end of the magnetic tape in order to draw out the magnetic tape from the cartridge casing.
BACKGROUND OF THE INVENTION
As a recording medium for use in an external memory of a computer or the like, there has been known a magnetic tape cartridge comprising a magnetic tape wound around a single reel and a cartridge casing in which the reel is housed for rotation. Since the magnetic tape is used for storing data in a computer or the like and important information is stored on the magnetic tape, the magnetic tape cartridge is structured so that trouble such as tape jam does not occur and the magnetic tape is not accidentally drawn out.
A leader member (a leader pin in the present invention) is fixed to the leading end of the magnetic tape and the recording and reproducing apparatus is arranged to catch the leader member to draw out the magnetic tape from the magnetic tape cartridge and to rewind the magnetic tape into the magnetic tape cartridge. The leader pin is removably held inside an opening of the cartridge casing which is opened and closed by a sliding door. It is preferred that a lock member which firmly holds the both ends of the leader pin be provided so that the leader pin can be held in a predetermined position.
It is necessary to stabilize leader pin holding and releasing action of the lock member and sliding door opening and closing action in order to improve reliability of the magnetic tape cartridge.
That is, when the magnetic tape, which has been drawn out form the cartridge casing, is rewound around the reel and the leader pin is stored inside the opening of the cartridge casing, the lock member is brought into abutment against the leader pin to be deformed or displaced, and is returned to its original shape or position to be brought into engagement with the leader pin after the leader pin is moved to a predetermined rest position in which the leader pin is stored. In this case, it is preferred from the viewpoint of stabilizing the leader pin holding action of the lock member that the entrance part of the lock member which is first brought into contact with the leader pin be gently inclined. However, when the inclination of the entrance part of the lock member is gentle, the lock member is apt to be long and it becomes necessary to position the lock member to project toward the opening. The position in which the leader pin enters the cartridge casing (will be referred to as “the leader pin introduction position”, hereinbelow) slightly varies in the direction of width of the opening, and accordingly, the entrance part of the lock member must permit variation of the leader pin introduction position over a sufficient range. Also for the purpose of this point, it is preferred that the entrance part of the lock member be positioned to project toward the opening. When the entrance part projects toward the opening, there arises fear that the entrance part interferes with the sliding door.
It is preferred that the rest position of the leader pin be near to the opening since the leader pin holding member of the recording and reproducing apparatus which catches the leader pin is inserted through the opening to be brought into engagement with the leader pin. As a result, the lock member is disposed near to the opening and the sliding door. Accordingly, when drop impact acts on the magnetic tape cartridge, there is fear that the lock member comes to interfere with the inner surface of the sliding door to disable the sliding door from being opened, which deteriorates the reliability of the magnetic tape cartridge.
Further, when impact acts on the magnetic tape cartridge in the state where the leader pin is held in the rest position, e.g., while the magnetic tape cartridge is stored or being transported, with the magnetic tape slackened, the leader pin can be released from the lock member or can come to be held by the lock member in a wrong position deviated from the rest position. When the leader pin is once shifted from the correct rest position, there is no force acting on the leader pin to return it to the correct rest position, and the leader pin is kept deviated from the correct rest position. Accordingly, when the magnetic tape cartridge is subsequently loaded in a recording and reproducing apparatus, the leader pin holding member cannot hold the leader in the correct position, which causes trouble in operation of the recording and reproducing apparatus and deteriorates the reliability of the magnetic tape cartridge.
Further, it is necessary to provide on the sliding passage of the sliding door a spring member for urging the sliding door toward its closing position. However the sliding stroke of the sliding door is relatively long, and it is difficult to dispose a spring member conforming to such a long sliding stroke of the sliding door in a limited space, which makes it difficult to obtain desired spring characteristic.
Further, use of a coiled spring which is large in length/diameter ratio as the spring member gives rise to a problem that since the coiled spring is incorporated in the cartridge casing in a slightly compressed state, the coiled spring can buckle to spring back out of the predetermined position or to be pinched between upper and lower casing halves forming the cartridge casing, which deteriorates assembling facility of the magnetic tape cartridge.
In view of the foregoing observations and description, the primary object of the present invention is to provide a magnetic tape cartridge in which reliability of leader pin holding action of the lock member and reliability of the sliding door opening and closing action can be ensured.
SUMMARY OF THE INVENTION
The object of the present invention can be accomplished by a magnetic tape cartridge comprising a cartridge casing, a single reel which is housed in the cartridge casing for rotation and around which a magnetic tape is wound, the leader pin which is fixed to the leading end of the magnetic tape in order to draw out the magnetic tape from the cartridge casing, a lock member which is adapted to removably hold opposite ends of the leader pin inside an opening of the cartridge casing, and a sliding door for opening and closing the opening, wherein a recess is formed on the inner surface of the sliding door at least at a part opposed to the lock member.
It is preferred that the recess be formed so that the recess on the front end of the sliding door is closed by a wall surface of the cartridge casing when the sliding door is closed. The lock member may comprise upper and lower parts which are formed of a wire spring or a plate spring integrally with each other or separately from each other.
In accordance with the magnetic tape cartridge described above, by virtue of the recess formed on the inner surface of the sliding door at least at a part opposed to the lock member, interference of the lock member with the sliding door can be prevented and generation of failure in opening and closing the sliding door can be prevented. Further, freedom in the shape of the lock member is increased and the entrance portion of the lock member against which the leader pin is first brought into abutment can be gentle in inclination and sufficient in width, whereby leader pin holding action can be stabilized and reliability of the magnetic tape cartridge can be improved.
When the recess on the front end of the sliding door is closed by a wall surface of the cartridge casing when the sliding door is closed, dirt and dust are preventing from entering the cartridge casing and deterioration of recording quality can be prevented.
In a magnetic tape cartridge in accordance with ano
Ishihara Yusuke
Morita Kiyoo
Shiga Hideaki
Takahashi Daisuke
Tsuyuki Seiji
Fuji Photo Film Co. , Ltd.
Nguyen John Q.
Sughrue & Mion, PLLC
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