Winding – tensioning – or guiding – Unwinding and rewinding a machine convertible information... – Cartridge system
Reexamination Certificate
2001-04-05
2002-12-31
Nguyen, John Q. (Department: 3654)
Winding, tensioning, or guiding
Unwinding and rewinding a machine convertible information...
Cartridge system
C360S132000
Reexamination Certificate
active
06499686
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a magnetic tape cartridge and more particularly relates, in a magnetic tape cartridge where a single reel with magnetic tape wound there on is rotatably housed within a cartridge case, to the structure of reel-rotation restraining means which causes the reel to be in a rotation-restrained state when not being used.
2. Description of the Related Art
In the magnetic tape cartridges, which are used as storage medium to be employed in external storage units for computers, etc., there is known a type where a single tape reel with magnetic tape wound thereon is rotatably housed within a cartridge case. This magnetic tape is employed as a data archiving tape for computers, etc., and stores important information. For this reason, the magnetic tape cartridge is provided with reel-rotation restraining means for restricting rotation of the reel so that problems, such as tape jamming, etc., do not occur and that the magnetic tape is not pulled out from the cartridge case unexpectedly when not being used, such as when being archived, etc.
The reel-rotation restraining means, as disclosed in Japanese Unexamined Patent Publication No. 11(1999)-23835, is equipped with a restraining member for restricting rotation of the reel, an urging member for urging the restraining member in a restraining direction, and an unlocking member for moving the restraining member in an unlocking direction in accordance with the chucking operation of the rotation means of the drive mechanism of a drive unit such as a recording-reproducing unit.
A locking tooth portion is formed on the reel side, while a restraining gear meshable with the locking tooth portion is provided on the side of the restraining member provided so that it cannot rotate with respect to the cartridge case. In the non-operative state, the restraining gear of the restraining member engages the locking tooth portion of the reel to restrict unexpected rotation of the reel, whereby the magnetic tape wound on the reel can be locked. On the other hand, if the magnetic tape cartridge is loaded into the drive unit, the unlocking member moves the restraining member to disengage the restraining gear of the restraining member from the locking tooth portion of the reel. In the disengaged or unlocked state, the reel is rotatable and therefore the magnetic tape can be loaded into or unloaded from the drive unit.
The above-mentioned unlocking member is equipped with a main body which abuts the above-mentioned restraining member, and leg portions which abut the rotation means of the drive mechanism of the drive unit. When the chucking operation of the rotation means is performed, the rotation means moves the unlocking member upward to disengage the retraining gear of the restraining member from the locking tooth portion of the reel.
In the case where a magnetic tape cartridge is equipped with the reel-rotation restraining means mentioned above, incidentally, the restraining member in the unlocked state is unstable because the central portion of the restraining member is supported only by the central portion of the unlocking member. On the other hand, because the reel is rotated or stopped according to loading or unloading of the magnetic tape, the force exerted on the reel is transmitted to the restraining member through the unlocking member. For this reason, the restraining member tends to tilt. If the restraining member tilts, the restraining gear thereof will contact the locking tooth portion of the reel. This produces an undesirable sound, disturbs rotation of the reel, and interferes with the operation of loading or unloading magnetic tape.
In addition, in the case where the magnetic tape slackens because of the shock produced by the magnetic tape cartridge falling when not being used, the magnetic tape cartridge cannot absorb the slack of the magnetic tape because it has only a single reel within the cartridge case. As a result, there is a fear that the magnetic tape will be damaged. Hence, in order to prevent the magnetic tape from slackening because of shock caused by the cartridge falling, the locking tooth portion of the reel and the restraining gear are constructed so that the tooth face of the locking tooth portion, which faces in the reverse winding direction (tape slackening direction), and the tooth face of the restraining gear, which abuts the tooth face of the locking tooth portion, are inclined at an angle near to 90 degrees.
However, in the case where the reel in the non-operative state is unexpectedly locked by the mesh between the restraining gear and the locking tooth portion, there are cases where the reel is freely moved by the complete mesh between the restraining gear and the locking tooth portion, depending on the phase relationship between the two in the unmeshed state. Particularly, if the tooth face of the locking tooth portion, which faces in the reverse winding direction (tape slackening direction), and the tooth face of the restraining gear, which abuts the tooth face of the locking tooth portion, are inclined at an angle near to 90 degrees in order to prevent slackness, as described above, the locking tooth portion and the restraining gear move only in the winding direction when they mesh with each other, and consequently, force is exerted on the magnetic tape in the winding direction.
In addition, in the case of a magnetic tape cartridge with magnetic tape wound on a single reel, a tape leader member is coupled with the leading end of the magnetic tape, and the tape leader member is caught by the catching member of the drive mechanism of a drive unit to pull out the magnetic tape from the cartridge case. In this construction, if the tape leader member is exposed to the case peripheral side, there is a problem that the free end will project from the cartridge case, or dust will enter the cartridge case through a tape leader opening formed in the cartridge case, when the magnetic tape cartridge is subjected to a falling shock, etc. Hence, it is disclosed in Japanese Unexamined Patent Publication No. 11(1999)-232828 that a tape leader pin is retained inside a tape leader opening which is closed or opened by a slide door. The configuration of the tape leader member is determined mainly by specifications for the recording-reproducing unit.
Thus, in the case where the tape leader pin is coupled with the leading end of the magnetic tape, and the tape leader pin is retained with in the cartridge case during the non-operative state, if the reel is moved in the winding direction and a pulling force greater than a predetermined quantity is exerted on the magnetic tape, there is a fear that the magnetic tape and the tape leader pin will be easily disengaged from each other, because the strength of the engagement of the tape leader pin with the magnetic tape is relatively low. Even when the two are not disengaged, the magnetic tape will be stretched by the aforementioned pulling force. Because of this, the magnetic recording-reproducing characteristics are degraded, or the tape leader pin is shifted out of a predetermined retaining position or tilted. Thereafter, there is a fear that the magnetic tape cannot be correctly loaded into the drive unit and therefore reliability will be reduced.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-mentioned points. Accordingly, it is a first important object of the present invention to provide a magnetic tape cartridge which is capable of preventing the contact between a restraining gear and a locking protrusion that is caused by the tilt of the restraining member.
A second important object of the invention is to provide a magnetic tape cartridge that is capable of preventing the disengagement of the magnetic tape from a tape leader pin which is caused by the magnetic tape pulled in the locked state when subjected to a falling shock, while assuring the locked state of a reel obtained in a non-operative by the restraining member of reel-rotation restraining means.
To achieve the
Ishihara Yusuke
Shiga Hideaki
Takahashi Daisuke
Tsuyuki Seiji
Nguyen John Q.
Sughrue & Mion, PLLC
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