Disk Cartridge

Details Disk Cartridge Disk Cartridge

1995-04-21

2001-08-28

Cao, Allen T. (Department: 2652)

Dynamic magnetic information storage or retrieval

Record medium

In container

Reexamination Certificate

active

06282059

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to a cartridge for recording medium, and more specifically to a shutter for opening and closing the head access slot of a cartridge for recording medium.
A conventional disk cartridge for recording medium will be described below in conjunction with
FIG. 1
illustrating an embodiment of the present invention. Generally, a disk cartridge
10
is equipped with a shutter
50
that opens and closes openings
31
formed in the upper and lower shells of the cartridge case, the openings combinedly forming a slot for the access of a magnetic head. When the cartridge is not in use, the shutter
50
is urged by a spring in one direction to close the head slot
31
(FIG.
1
(
a
)) and, when the cartridge is used, the shutter is moved in the opposite direction by a mechanism of a drive unit to an open position (FIG.
1
(
b
)). The shutters of this character in extensive use thus depend merely on spring action for their closure and can be easily opened by children. The tampering can damage the recording media housed in the cartridges. Because of this concern and also because of the potential application to the cartridges for game software, an early improvement in the closing mechanism has been awaited.
Provision of some locking member to keep the shutter immovable when not in use has already been proposed.
However, the prior art cartridges equipped with such locking members have one disadvantage or another. For example, the cartridge must be thick enough to form a groove or notch that is required to receive an unlocking member (Japanese Utility Model Application Kokai No. 56377/1983). An unlocking part for the locking member provided in the space between the upper and lower case shells or inside the shutter complicates the construction of the unlocking member and the shutter opening-closing member on the part of the recording-reproducing unit (Japanese Patent Application Kokai No. 56377/1994).
The prior art structures will now be considered in detail.
FIG. 4
shows a shutter locking mechanism for a disk cartridge described in Utility Model Application Kokai No. 56377/1983. A slide shutter
120
is disposed between upper and lower shells
111
(only one of which is shown) of a cartridge case containing a magnetic disk. The shutter is biased by a spring in the direction of an arrow A. In one piece with the inner wall at a corner of the case made up of the upper and lower shells, there is formed a locking member
133
having a locking pawl
137
at the front end, generally in the form of a cantilever plate spring. The locking member
133
is formed substantially in parallel with one edge of the case. The space above the locking member
133
constitutes a guide groove
125
defined by the upper and lower shells, along which an unlocking pin
128
of a recording-reproducing unit is to slide.
Normally the shutter
120
is shifted in the direction of an arrow A where its locking hole
139
is engaged with the locking pawl
137
. As the disk cartridge is loaded into the recording-reproducing unit, the unlocking pin
128
enters the guide groove
124
from the direction of an arrow B, depresses a protuberance
138
of the locking member
133
, thereby releasing the pawl
137
from the locking hole
139
of the shutter
120
, and finally opens up the shutter
120
.
The locking mechanism is disadvantageous in that the guide groove
125
required to guide the unlocking pin renders it impossible to reduce the overall thickness of the case of the disk cartridge. Another disadvantage is the questionable reliability of locking, since the locking member, a cantilever type having the locking pawl
137
distant from the supported base and molded of plastic material, becomes unable to maintain precise locking pawl engagement after repeated use.
Patent Application Kokai No. 60592/1994 teaches a shutter locking spring
206
as shown in
FIG. 5. A
slide shutter
202
is mounted astride on one edge portion of a disk cartridge
201
and is normally biased leftwards as viewed in the figure by a spring
205
. The shutter locking spring
206
is a cantilever spring fixed at the base to the cartridge case. It has a locking dent
207
near its free end, which is adapted to receive a locking protuberance
203
formed on the shutter, so as to lock the shutter in the closing position. The case is formed with a groove
214
to receive an unlocking pin
210
.
This locking mechanism again requires the groove
214
to guide the unlocking pin, which hampers an effort to reduce the overall thickness of the disk cartridge case. Similarly, the other disadvantage is the inability of ensuring positive locking. The cantilever type locking member, the long distance from its base to the locking dent
207
, and the plastic molding combine to make it gradually difficult, after repeated use, to maintain exact locking pawl engagement.
In view of these, there has been a demand for a cartridge that eliminates these disadvantages of the prior art and provides perfect protection for the recording medium contained.
The present invention therefore has for its object to provide a cartridge whose shutter can be positively locked when closed to provide perfect protection for the recording medium, and which is reduced in overall thickness and simplifies the unlocking mechanism and shutter-opening-closing mechanism of the recording-reproducing unit with which the cartridge is used.
SUMMARY OF THE INVENTION
The cartridge according to this invention comprises a case consisting of upper and lower shells joined and containing a medium, a shutter which slides astride over one edge portion of the case to open or close a slot formed in the case to expose the medium partly, and a locking member which keeps the shutter in the closing position immovably, said locking member being normally, except when unlocked, exposed partly in a recess for the access of an unlocking member, so that a push of the exposed portion of the locking member disengages it from a projection formed on the inner side of the outer edge of the shutter.
Preferably, means for confining the position of the exposed portion of the locking member always to the inside of the line extended from the end face of the shutter, is fixed to the interior surface of the case.
To be more concrete, the end face of the case has a recess formed in the portion adjacent to the shutter, defined by a cutout across the entire thickness of the case, to receive an unlocking member from a recording-reproducing unit, while the locking member is partly exposed to the recess so that when the unlocking member pushes the locking member on the exposed portion the locking member is disengaged from the projection inside the end face of the shutter.
The recess for the access of the unlocking member, thus formed by a cutout across the entire thickness of the case, permits the use of an unlocking pin thinner than the disk cartridge, rendering it possible to reduce the thickness of the cartridge accordingly.
Moreover, the means for confining the position of the exposed portion of the locking member always to the inside of the line extended from the end face of the shutter ensures exact locking pawl engagement regardless of qualitative dispersion among the locking members produced or of minor errors in their assembling. The means also avoids direct contact with the fingers from the outside and prevents the opening of the shutter by tampering.
More preferably, the locking member comprises a base secured to the inner wall of the case, a back exposed to the cutout recess, a hooked head extending from the back and made engageable with an engaging projection formed in the shutter, and a flexible leg formed between the base and the back to urge the hooked head normally in the direction of the projection. Still more preferably, the locking member further comprises means for confining its exposed portion always to the inside of the line defined by the end face of the shutter. The confining means may consist of an arm formed in one piece with the back, the arm being limited in motion

Affiliated with

Also associated with

Rating

Disk Cartridge does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Disk Cartridge, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disk Cartridge will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2435811