JPH03283064A - Recording cartridge - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording cartridge such as a magnetic disk cartridge, an optical disk cartridge, or a magnetic tape cartridge, and particularly relates to a shutter thereof.

[Prior Art] FIG. 1 is a perspective view of a magnetic disk cartridge, FIG. 2 is a sectional view taken along line 1--2 in FIG. 1, and FIG. 3 is a perspective view of a shutter used in the magnetic disk cartridge.

A flexible magnetic disk 2 is rotatably housed inside a cartridge case 1 constructed by combining an upper case 1a and a lower case lb (see FIG. 2). The front part of this cartridge case 1 has a stepped recess 3.
is formed, and a magnetic head insertion opening 4 is provided approximately in the center thereof. A shutter 5 for selectively opening and closing the magnetic head insertion port 4 is slidably supported within the recess 3.

By the way, this shutter 5 is made of metal or synthetic resin. In the case of a metal one, the sliding surface of the recess 3 is scraped by the edge of the shutter 5 when it is activated.
Synthetic resin shavings are generated. This adheres to the magnetic disk 2, making it more likely that errors will occur during recording and reproduction.

To prevent this, cartridge case 1 and shirt cap 5 are
If a large clearance is provided between the shutter 5 and the shutter 5, dust will easily enter from around the shutter 5, and the dust will adhere to the magnetic disk 2, causing errors during recording and reproduction.

On the other hand, when a synthetic resin shutter 5 is used, unlike a metal one, there is no problem of scraping of the recess 3, so the shutter 5 can be brought into elastic contact with the surface of the cartridge case 1 (recess 3). This makes it possible to effectively prevent dirt from entering from around the shutter 5.

As shown in FIGS. 2 and 3, this synthetic resin shutter 5 connects two opposing plane plate parts 6.6 and one end edge of both plane plate parts 6, 6. Connecting plate part 7
It is mainly composed of , and the side shape is almost U-shaped. The flat plate portion 6 has an opening 8 of approximately the same size as the magnetic head insertion port 4 and a closing portion 9 that closes the magnetic head insertion port 4. As shown in FIG. 1, the shutter 5 is always elastically biased by a spring member (not shown) in a direction in which the closing portion 9 closes the magnetic head insertion port 4. As shown in FIG.

A hook-shaped protrusion 10 is provided on the inner surface of the connecting plate portion 7. This hook-shaped protrusion 10 engages with a guide groove 11 formed inside the cartridge case 1 as shown in FIG. 2, and the shutter 5 is removed from the cartridge case 1 when sliding. I try not to. This protrusion 1
In the portion of the flat plate portion 6 facing the root portion 10a of the mold, there is an opening 12 formed when the mold is removed.

[Problems to be Solved by the Invention] FIG. 15 is a sectional view of a conventional shutter 5, and FIG. 16 is a perspective view for explaining a modification of the shutter 5.

As shown in FIG. 15, in the conventional shutter 5, the plate thickness T5 of the connecting plate part 7 is considerably thicker than the plate thickness T1 near the base of the flat plate part 6 with the connecting plate part 7. There is.

Further, the plate thickness T2 on the free end side of the plane plate part 6 is
It is equal to the plate thickness T1 near the base of the connecting plate part 7.

However, as mentioned above, the plate thickness T5 of the connecting plate part 7 is the plate 7 near the base of the connecting plate part 7 of the flat plate part 6! If it is thicker than XTl, the connecting plate portion 7 will curve convexly toward one plane plate portion 6 as shown by the dotted line in FIG. 16 during molding.
As a result, the vicinity of the edge of the opening 8 on the connecting plate part 7 side is depressed inward, and the free end sides of both plane plate parts 6 are further deformed to open slightly as shown by dotted lines.

When the shutter 5 is deformed in this way, the sliding resistance with the cartridge case 1 increases, resulting in poor operability of the shutter 5. Furthermore, the recess 3 formed in the cartridge case 1 restricts the movement range of the shutter 5. However, as mentioned above, if the free end side of the shutter 5 starts to open,
The free end of the shutter 5 may climb over the recess 3, causing problems such as the shutter 5 coming off from the cartridge case 1.

The purpose of the present invention is to eliminate such drawbacks of the prior art,
To provide a recording cartridge equipped with a shutter free from molding defects.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention includes a cartridge case for storing a recording medium, a synthetic resin shutter for opening and closing a head insertion port formed in the cartridge case, and a cartridge case for storing a recording medium. , and the shutter has two planar plate portions facing each other and a connecting plate portion that connects one edge of each of the two planar plate portions, the connecting plate portion of the flat plate portion and The plate thickness T1 near the base of the plate is thicker than the plate thickness T5 of the connecting plate portion.

[Function] As described above, the present invention makes the plate thickness T1 near the base of the flat plate part with the connecting plate part thicker than the plate thickness T5 of the connecting plate part (TI>T5), thereby achieving the theoretical Although the reason is not clear, it is possible to obtain a shutter in which the connecting plate part, the edge of the opening on the connecting plate part side, and the free end side of the flat plate part are not deformed as in the conventional case.

[Example code] Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 4 is a plan view of the shutter according to the embodiment, and FIG.
Figure 6 is a cross-sectional view taken along line A-A in Figure 4, Figure 7 is a cross-sectional view taken along line B-BwA in Figure 4, and Figure 7 is a cross-sectional view of the entire shutter before it is filled with synthetic resin during mold clamping of the injection molding machine that molds the shutter. Figures 8 and 9 are cross-sectional views of the main parts of the mold for molding the parts shown in Figures 5 and 6 before being filled with the synthetic resin, and Figure 1O is the injection mold. FIG. 11 is an overall sectional view of the injection molding apparatus when the mold is closed and filled with synthetic resin, and FIG. 11 is an overall sectional view of the injection molding apparatus when the mold is opened.

Examples of the molding material for the shutter 5 include copolymer polyacetal, homopolymer polyacetal, polypropylene, polymer alloy of polypropylene and polyamide,
Synthetic resins such as ABS@fat are used. As shown in FIGS. 4 to 6, this shutter 5 has two planar plate portions 6.degree. The planar plate portion 6 has a substantially U-shaped side surface (see FIG. 5). An opening 8 of a certain size and a closing portion 9 that closes the magnetic head insertion port 4 are formed. Further, as shown in FIG. 6, on the inner surface of the connecting plate portion 7, there is a hook-shaped protrusion 10 that engages with a guide groove 11 formed inside the cartridge case 1 (see FIG. 2). Two pieces are provided at a predetermined interval. In the portion of the flat plate portion 6 facing the root portion of the second protrusion 10, there is an opening 12 formed when the mold is removed (see FIG. 4).

As shown in FIG. 4, when the shutter 5 is injection molded, the gate G is located at the opposite side of the first side edge 24 of the connecting plate portion 7 that is in contact with the shutter opening member 14 of the recording/reproducing device. It is provided only on the side edge 25 of 2. By providing a single point gate at such a position, even if a crisp gate mark is formed, it will not come into contact with the shutter opening member 14.

Next, the thickness T of the flat plate portion 6 will be explained.

As shown in FIG. 5, with respect to the plate thickness Tl near the base of the flat plate part 6 and the connecting plate part 7, the plate thickness T2 of the free end side of the connecting plate part 7 opposite to the base part gradually increases. It has become thicker (
Tl<T2). Also, unlike the conventional case, the plate thickness T1 is thicker than the plate thickness T5 of the connecting plate portion 7 (TI>T
5).

In addition, as shown in FIG.
The plate thickness T4 on the opposite side gradually becomes thicker (T3<
T4), that is, in FIG. 4, the plate thickness T of the plane plate portion 6
The plate thickness T becomes thicker as it goes in the arrow X direction and the arrow Y direction with the gate mark (gate G) as the center.

The rate of increase of the plate thickness T2 with respect to the plate thickness T1 and the rate of increase of the plate thickness T4 with respect to the plate thickness T3 are 1 to 15%, preferably 2 to 10%.

A specific example of the plate thickness T for a 3.5-inch magnetic disk cartridge is as follows.

Tl=0.38mm T2=0.40mmT3=0
．． 39mm T4=0.40mmT5=0.35m
m Next, the structure of an injection molding apparatus for molding such a shutter 5 will be explained with reference to FIGS. 7 to 11.

In these figures, 16 is a fixed mold, 17 is a movable mold, and 18 is a slide core placed i2 with a predetermined gap between the fixed mold 16 and the movable mold 17. Although not shown, #19 is configured to slide with an angular pin or an air cylinder, etc., and #19 is an extended fixed side protrusion contour forming portion on the movable mold 17 side, which is integrated with the fixed mold unit 6. Provided on the movable mold 17 side,
This is a movable side protrusion contour forming portion that faces the fixed side protrusion contour forming portion 19 . For example, two pairs of the fixed side protrusion contour forming section 19 and the movable side protrusion contour forming section 20 are provided at a predetermined interval in the direction perpendicular to the plane of the paper of FIG. 21 is a runner block. Further, as shown in FIG. 9, the fixed mold 16 and the movable mold 17 have a fixed side head insertion hole contour forming part 26 and a movable side head insertion hole contour forming part 26 integrally extending to the slide core 18 side. Forming portions 27 are provided respectively.

As shown in FIGS. 7 to 9, before the mold is clamped and filled with resin, the fixed mold 16 and the slide core 18
A plane plate forming space 22 with a relatively narrow gap is formed between the movable mold 17 and the slide core 18.

In addition, a fixed mold 16, a movable mold 17, and a slide core 18
, fixed side protrusion contour forming section 19 and movable side protrusion contour forming section 2
0, a connecting portion (protrusion) forming space 23 is formed.

As mentioned above, in order to vary the thickness T of the flat plate portion 6,
As shown in FIGS. 8 and 9, the digging depth S of the plane plate forming space 22 is on the opposite side to the digging depth Sl near the joint with the connecting plate forming space 23. The free end m of the digging depth S2 gradually becomes deeper (S
l<32 (see Figure 8), and the digging depth S
l is designed to be deeper than the digging depth S5 of the connection plate forming cavity rJJ23 (Sl>95, see Figure 8)
.

Furthermore, with respect to the digging depth S3 on the gate side of the plane plate forming space 22, the digging depth S4 on the side opposite to the gate G
is gradually deepening.

In such a state (see Figures 7 to 9),
As shown in FIG. 10, each space 22.
23 is filled with a molten synthetic resin, and the resin is cooled and solidified in a subsequent pressure holding step. and the 11th
As shown in the figure, the slide core 18 is
The slide core 18 is moved leftward toward the plane of the paper by the angular pin or cylinder, and the movable mold 17 is moved backward. Thereafter, the shutter 5 is ejected from the molding device by an eject pin.

Figure 12 shows the 2
FIG. 3 is a plan view of an individual shutter molded body.

As shown in the figure, the molded body molded with a single point gate and discharged from the molding apparatus has two shutters 5 connected by a runner 28.

Figure ff113 is an enlarged sectional view taken along line 1-f in Figure 12. In the case of this embodiment, as shown in the figure, a large number of protrusions 29 and grooves 30 are alternately formed on the surface of the plane plate portion 6 from the first side end #14 to the second side end @15. It is formed.

FIG. 14 is a plan view showing an embodiment in which two shutters of the present invention are applied to an optical disk cartridge.

As shown in the figure, the cartridge case 31 has an elongated opening 32 in which the head insertion port and the drive shaft insertion port communicate with each other.
is formed. A synthetic resin shutter 33 that selectively opens and closes the opening 32 is slidably supported on the cartridge case 31. An optical disk 35 having a hub 34 in the center is rotatably housed in the cartridge case 31.

Note that the shutter 33 is molded from synthetic resin as in the previous embodiment, and has two planar plate portions facing each other.

It has a connecting plate part that connects one edge of the WM part in both years, and the thickness T1 of the flat plate part near the base of the connecting plate part is the same as that of the connecting plate part. The plate thickness T2 on the opposite free end side gradually increases. Moreover, the plate thickness T4 on the side opposite to the gate trace side gradually becomes thicker than the plate thickness T3 on the gate trace side of the plane plate portion. In addition, 36 in the figure
37 is an opening provided when forming a protrusion (not shown) in the shutter 33, and 37 is a plate that slidably presses the free end of the shutter 33.

[Effects of the Invention] As described above, the present invention achieves the theory by making the plate thickness T1 near the base of the flat plate part with the connecting plate part thicker than the plate thickness T5 of the connecting plate part (Tl>T5). Although the basis thereof is not clear, it is possible to obtain a shutter in which the connecting plate portion, the edge of the opening on the connecting plate side, and the free end side of the flat plate portion are not deformed as in the conventional case. Therefore, the shutter is easy to operate,
It is possible to provide a recording cartridge with high operational reliability in which the shutter does not come off from the cartridge case.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a magnetic disk cartridge. FIG. 2 is a sectional view taken along the line ■-■ in FIG. FIG. 3 is a perspective view of a shutter used in the magnetic disk cartridge. 4 is a plan view of a shutter according to an embodiment of the present invention, FIG. 5 is a sectional view taken along line A-4 in FIG. 4, and FIG. 6 is a sectional view taken along line B-B in FIG. Figure 7 is a general cross-sectional view of the injection molding machine that molds the shutter, before it is filled with synthetic resin. 5 and 6, and FIG. 10 is an overall sectional view of the injection molding apparatus in a state filled with synthetic resin when the mold is clamped. Fig. 11 is an overall sectional view of the injection molding apparatus when the mold is opened, and Fig. 12 is a cross-sectional view of the injection molding apparatus when the mold is opened.
The plan view of the individual shutter molded bodies, FIG.
FIG. 14 is an enlarged cross-sectional view taken along the line in FIG. 1-1, and is a plan view showing an embodiment in which the shutter of the present invention is applied to an optical disk cartridge. FIG. 15 is a sectional view of a conventional shutter, and FIG. 16 is a perspective view for explaining a modification of the shutter. 1...Cartridge case, 2...Magnetic disk, 4...Magnetic head insertion slot, 5...
...Shutter, 6...Flat plate part, 7...
・Connecting plate part, 8...Opening, 9...Closing part, 14...Shutter opening member, 16...
...Fixed mold, 17...Movable mold, 22...
... Plane plate part forming space, 23... Connecting part forming space,
24... First side edge, 25... Second side edge, 26... Fixed side head insertion port contour forming part, 27...
...Movable side head insertion port contour forming part, TI, T2
．． T3゜T4・・・Thickness of plane plate part, Sl, S2
．． S3. S4: Digging depth. Figure Figure Figure 4 Figure Figure Figure Funeral Figure Funeral Figure Not Figure Figure 10 Figure 12 Figure 13 Figure 14 Figure 15 Figure 6

Claims (1)

[Claims] It is equipped with a cartridge case that stores a recording medium, and a synthetic resin shutter that opens and closes a head insertion port formed in the cartridge case, and the shutter has two planar plate parts facing each other and both planar plate parts. In the recording cartridge having a connecting plate portion that connects one edge of the planar plate portion with the connecting plate portion, a plate thickness T1 near the base of the flat plate portion with the connecting plate portion is thicker than a plate thickness T5 of the connecting plate portion. A recording cartridge characterized by: