CN1007188B - Tape cassette - Google Patents

Abstract

The present invention relates to a tape cassette which comprises a cassette body, a tape disc and a groove, wherein the cassette body is shaped by the casting of melting resin and is provided with an upper half part and a lower half part; the tape disc can be rotatablely arranged in the cassette body and provided with a lower wheel disc; the groove is arranged at the outer surface of the bottom wall of the lower half part and is adjacent to the lower wheel disc of the tape disc. The present invention has the improvement that at least one bulge part is arranged at the inner surface of the bottom wall of the lower half part of the cassette body and covers the groove so as to promote the flow of the melting resin near the groove when the lower half part is shaped.

Description

Tape cassette

The present invention relates to a kind of tape cassete that is specially adapted to record with reproducer, particularly such as the tape cassete of video tape recorder, it comprises a casket body or the outer cover be made up of the first half and Lower Half, casket body or outer cover are by synthetic resin die casting being entered in the mould and moulding, also comprise and be installed in the casket body and revolvable tape reel, this tape reel has wheel disc at least, also comprise a groove that on Lower Half casket body diapire outside surface, forms, be positioned to the small part groove and be close to each casket body half area of wheel disc down.

A kind of common tape cassete that is used for video tape recorder is described referring now to Fig. 1 and Fig. 3:

Referring to Fig. 1 and Fig. 2, casket body 1 is made up of the vertically opposite first half 2 and Lower Half 3, and per half one unifies by the synthetic resin die cast and with similar things such as bolts.A pair of tape reel 4 is rotatably mounted in the casket body 1, and tape 5 can be around on the dish 4.There is an open front 6 on one side of casket body 1, also has a protecgulum 7, and protecgulum 7 is contained in the open front 6 to cover casket body 1 on the casket body around pivot.Tape 5 is led by a pair of tape guidance device 8, and moves along protecgulum 7 inner surfaces in open front 6.

Each is fixed on the tape reel 4(Fig. 2 in the casket body 1) have on one wheel disc 9 and a wheel disc 10 once.Ring-type axle sleeve 11 protrudes downwards from the Lower Half center of tape reel 4 and is rotatable, and loosely is inserted in the axis hole 12 that forms on the diapire of Lower Half 3 of casket body 1.At least one reed 13 is contained in the gap between the last round of dish 9 of the upper wall of the first half 2 and tape reel 4.Each reed 13 upper surface centre on each corresponding tape reel 4 along the vertically fixing and two ends roof pressure each reed 13 of the first half 2 upper wall inside surface 2a.Therefore, as shown in Figure 2, in axle sleeve 11 patchholes 12 of tape reel 4.The lower surface 10a of following wheel disc 10 leans against on the inside surface 3a of Lower Half and diapire tightly.

Gathering sill 15 along the casket body vertically, linearly be formed on the diapire outside surface 3b of casket body 1 Lower Half 3, (be among Fig. 1 from left to right direction) adjacent bores 12, gathering sill 15 traverses on the tape cassete Lower Half 3, with respect to the zone that is contained in the 4 times wheel discs 10 of tape cassete in the casket body 1.This class is used for the tape cassete of video tape recorder, and when in the video tape recorder that it is packed into, gathering sill 15 forms a kind of guide piece.In situation shown in Figure 3, the bottom wall thickness t1 of Lower Half 3 is 2 millimeters, and gathering sill 15 forms on the diapire outside surface 3b of Lower Half 3, and well width W1 is 3 millimeters.One opening 16(Fig. 1 is arranged in gathering sill 15 centres), it can be used as a jack that can hold axle sleeve locking release pin (not expressing), and this release pin is arranged in the video tape recorder.

As previously discussed, Lower Half 3 is by the synthetic resin casting forming.Fig. 3 illustrates the part of upper mold section 18a and the close groove 15 of female die 18b.One forms on mould 18b for the protuberance 19 of shaping gathering sill 15.Molten resin arrives in mould 18a and the determined cavity volume of 18b by filling orifice 20 die casting.After the resin cooling of injecting, the gathering sill that Lower Half 3 is had also just has been shaped.

Yet common tape cassete as shown in Figure 1 to Figure 3 exists following point.

Along with video tape recorder is popularized in family and office more and more in a large number; People's strong request has cheap tape cassete to come out.In order to meet this requirement, tape cassete is necessary can large-scale production.Yet tape cassete Lower Half 3 low is cast into the large-scale production that the type rate has hindered tape cassete.

When die cast Lower Half 3, molten resin from filling orifice 20 inject and along arrow a(Fig. 1) direction of indication is radial flowing to and forms Lower Half 3, filling orifice 20 is at Lower Half 3 rear portions, on the longitudinally RC position.At this moment, as shown in Figure 3, gathering sill 15 is formed by the protuberance 19 of mould 18b.Yet, owing to the protuberance of establishing for grooving 15 19 makes that the stenosis of gathering sill cavity part is little, those are along arrow b(Fig. 3) shown in the partial melting resin that flowing of direction, can be subjected to the restriction of narrow, its flowing velocity can reduce.Therefore cause the die cast of Lower Half 3 very consuming time, the die cast efficient of Lower Half 3 is reduced.

When the injection pressure that increases molten resin when improving resin flow speed, pressure, the particularly pressure of the narrow of die casting gathering sill 15 in the die cavity become very high.Thereby after molten resin solidified, Lower Half 3 will be bonded at mould 18a firmly and mould 18b goes up so that molding at an easy rate.When arrange the resin of two or more orifices on the gathering sill both sides with the casting fusion, so, from the molten resin that different orifices flows into, its flowing velocity difference.After molten resin solidifies, will form separatrix or sealing wire.The fusing line that comes across Lower Half 3 surfaces is as the lines that scrawl, and it has damaged the appearance of Lower Half 3.In addition, the physical strength of Lower Half 3 also can weaken.Owing to these reasons, preferably adopt a filling orifice 20 to inject molten resin.

Therefore, purpose of the present invention is exactly to improve the cast molding efficient of Lower Half significantly, when with molten resin casting Lower Half, does not promptly need two or more filling orifices also not need to increase injection pressure.

In order to reach above-mentioned purpose of the present invention, in this class tape cassete described above, promote to have at least a part to form a protuberance at Lower Half diapire inside surface and cover the part of gathering sill with this near the flowing of the molten resin of gathering sill cavity part.Had this structure, when with molten resin die cast Lower Half, because Lower Half diapire inside surface exists a protuberance that covers groove at least, Lower Half is just bigger near the thickness of trench portions, so the mobile of molten resin of close trench portions is good.Owing to this reason, even increase casting pressure indistinctively or two or more filling orifices are not provided, the casting time of Lower Half also can significantly reduce, and casting efficient also can significantly improve.Along with the development of tape cassete large-scale production, people can produce cheap tape cassete.

Figure 1 shows that prior art or be used for the backplan of the tape cassete of video tape recorder;

Fig. 2 is the amplification face figure that cuts open along prior art tape cassete II shown in Figure 1-II line.

Fig. 3 is the amplification profile of tape cassete major part shown in Figure 1, describes the casting principle of tape cassete Lower Half with this;

Fig. 4 is the planimetric map of the tape cassete Lower Half that partly prescinds of a tape reel, its objective is according to the embodiment of the invention to specify the tape cassete that is used for video tape recorder;

Fig. 5 is the Lower Half amplification profile of severing along Fig. 4 V-V line.

Fig. 6 is the amplification profile of tape cassete major part shown in Figure 4, describes the casting principle of Lower Half with this;

Fig. 7 is one similar to Fig. 5, according to the tape cassete amplification profile that is used for video tape recorder of second embodiment of the invention.

The present invention is applied to the tape cassete of video tape recorder shown in Fig. 4 to Fig. 7.The tape cassete and the same section among Fig. 4 to Fig. 7 of the common or prior art shown in Fig. 1 to Fig. 3 represent that with same label the description that prior art is detailed will be omitted.

The specific embodiments of the present invention that Fig. 4 to Fig. 6 shows, one according to tape cassete of the present invention in, the protuberance of going up on the corresponding inside surface 3a of gathering sill 15 with Lower Half 3 diapire outside surface 3b has the cross section that is roughly rectangle.Protuberance 22 is protruding upward, and its upper end face is one to be parallel to the surface level of inside surface 3a.Protuberance 22 forms on the zone of Lower Half 3 diapire inside surface 3a, and it covers gathering sill 15, and is wideer than gathering sill 15, and this zone is facing to the non-outer peripheral edge portion of the Lower Half surface 10a of 4 times wheel discs 10 of corresponding tape reel.For example, protuberance 22 wide w2 shown in Figure 6 are 7 to 8 millimeters, and high t3 is 0.10 to 0.14 millimeter.Yet, under normal conditions, high t3 can be in 0.05 to 0.5 millimeter scope, with reference to Fig. 4 to Fig. 6, its structure goes up the protuberance 24 that forms except that protuberance 22 and 4 times wheel disc 10 lower edge surfaces of each tape reel 10a, other parts kept with Fig. 1 to the identical structure of common magnetic tape cassette shown in Figure 3.

As shown in Figure 6, Lower Half 3 is molten resin die casting is gone between a pair of mould 18a and the 18b and to be shaped.For the groove 23 of shaping protuberance 22 forms on mould 18a.When molten resin when filling orifice 20 is injected between mould 18a and the 18b, the flowing (Fig. 6) along the arrow C direction partially of molten resin, gathering sill 15 and protuberance 22 are formed by protuberance on the mould 19 and groove 23.

In press casting procedure, above gathering sill, provide enough gaps owing to form the groove 23 of protuberance 22, molten resin can sharply not reduce owing to the protuberance 15 that is positioned at gathering sill 15 along the flow velocity of arrow C direction.Thereby shortened the casting time of Lower Half greatly, the ratio of briquetting of Lower Half 3 is provided.In addition,, just can tightly not be bonded on mould 18a and the 18b during Lower Half 3 moldings, can not occur sealing wire or other similar lines yet owing to needn't increase injection pressure and set up inlet.

As shown in Figure 5, except that the protuberance 22 that on Lower Half 3 diapire inside surface 3a, forms, 4 times wheel discs of each tape reel.There is a protuberance 24 to protrude on the 10 lower surface 10a downwards.Protuberance 24 at the outward flange of 4 times wheel disc 10 lower surface 10a of each tape reel with continuous or discontinuous annular side or form.For example, protuberance 24 high t4 are 0.2 millimeter.Yet because the existence of protuberance 24, tape reel 4 bottom wheel rims 10 lower surface 10a can be to float on the Lower Half 3 diapire inside surface 3a.In this case, form the gap 25 of a size between following wheel disc lower surface 10a and the diapire inside surface 3a corresponding to height t 4.Protuberance 22 is positioned within this gap 25, the two ends of each protuberance 22 be positioned at corresponding to protuberance 24 around the zone within, as shown in Figure 4.In other words, when tape reel 4 rotated, protuberance 22 placed protuberance 24 rotation gauge inboards.Owing to this reason, protuberance 22 just can not contact with tape reel 4 lower whorl lower surface, can not influence tape reel 4 rotations yet.The height t 3 of protuberance 22 preferably is selected in 0.10 to 0.14 millimeter scope, so the protuberance 22 unlikely lower surface 10a that run into corresponding wheel disc 10 down go up and make molten resin be easy to flow.

Fig. 7 has represented another embodiment of the present invention.In this embodiment, each protuberance 22 ' slot cross-section big supreme be triangle, it is towards the direction inclination of the corresponding fixedly axis hole 12 of tape reel.The in fact formed position of protuberance 22 is with embodiment illustrated in fig. 4 identical.Protuberance 22 ' height t 5 in 0.05 to 0.5 millimeter scope, preferably be selected in that embodiment is such as shown in Figure 4, in 0.01 to 0.14 millimeter scope.

According to this embodiment, even tape reel 4 is subjected to the very strong downforce of sheet spring 13, make its down wheel disc 10 from outward flange to centroclinal, as shown in Figure 7, thereby between lower surface 10a that descends wheel disc 10 and Lower Half 3 bottom interior surface 3a, formed a greatly most leg-of-mutton gap 25, protuberance 22 ' also can not collide with the lower surface 10a of wheel disc 10.

The upper end of protuberance 22 or surface preferably tilt like this; When wheel disc 10 tilted instantly, protuberance 22 ' upper end should be big to parallel or steeper with following wheel disc 10 lower surface 10a.In this embodiment, protuberance 22 ' width w ₃In 7 to 10 millimeters scopes.In the case, because 15 increases gradually from filling orifice 20 to gathering sill of the thickness of Lower Half 3, in casting cycle, flowing of molten resin will be smooth.

Though the present invention has given description by two instantiations, can produce various variations and modified version with reference to know-why of the present invention.For example, the protuberance 22 or 22 in above-mentioned two embodiment ' position and shape not only be confined to this two kinds of embodiments, people can do various variations according to the position and the shape of gathering sill 15.And, in above-mentioned two embodiment, the protuberance 24 on the following wheel disc 10 lower surface 10a be annular in case between the lower surface 10a of following wheel disc 10 and Lower Half 3 diapire inside surface 3a formation one gap.But protuberance 24 also can be discontinuous or forms groove on the almost whole lower surface 10a of each wheel disc 10, also may be corresponding to protuberance 22 or 22 ' that part of formation groove, so that between the lower surface 10a of wheel disc 10 down and Lower Half 3 inside surface 3a, form a gap complete or interruption.

In above embodiment, its description is carried out according to the double plate magnetic tape cassette.The present invention also is easy to be applied on the single-deck magnetic tape cassette.And application of the present invention is not limited only to the magnetic tape cassette of video tape recorder, and the magnetic tape cassette that can expand to various other recording/displaying devices and information control device gets on.

Claims (10)

1, a kind of tape cassete, comprise: a casket body with the first half and Lower Half with the synthetic resin casting forming, the a pair of tape reel that is rotatably installed in the above-mentioned casket body and has following wheel disc at least, a groove that is positioned on the above-mentioned casket body Lower Half diapire outside surface, it is characterized in that: on above-mentioned casket body Lower Half diapire inside surface, form a pair of first protuberance, and each tape reel has second protuberance that forms near wheel disc outer peripheral edges under it at least along described groove.

2,, it is characterized in that a smooth upper surface is arranged on described first protuberance according to the tape cassete of claim 1.

3,, it is characterized in that above-mentioned smooth upper surface is parallel to the diapire inside surface and extends according to the tape cassete of claim 2.

4,, it is characterized in that the relative diapire inside surface in above-mentioned smooth upper surface tilts at angle according to the tape cassete of claim 2.

5,, it is characterized in that the above-mentioned first protuberance upper surface is centroclinal to the tape reel of correspondence according to the tape cassete of claim 1.

6,, it is characterized in that above-mentioned first protuberance covers above-mentioned groove, and the width of first protuberance is greater than above-mentioned groove according to the tape cassete of claim 1.

7, according to the tape cassete of claim 1, the altitude range that it is characterized in that first protuberance is 0.05 to 0.5 millimeter.

8, according to the tape cassete of claim 1, the altitude range that it is characterized in that first protuberance is 0.10 to 0.14 millimeter.

9, according to the tape cassete of claim 1, it is characterized in that above-mentioned first protuberance is divided into two longitudinal extensions partly, and every part by second protuberance of separately tape reel around.

10,, it is characterized in that above-mentioned second protuberance forms with annular form along above-mentioned each following wheel disc outward flange according to the tape cassete of claim 9.

Images