GB2126561A - Magnetic tape cassette casing - Google Patents

Abstract

A cassette casing for containing magnetic tape is formed from four parts comprising first and second substantially planar plastic panels 1b, 1c and first and second metal frames 1a, 1d engaging around the respective panels and assembled to each other e.g. by screws for disposing the panels in substantially parallel relation. Interengaging means 13, 20, and 12, 18 on the frames and panels are provided for limiting outward movement of the panels, as well as abutting reinforcing means 19 on the panels for preventing inward movement of the panels. Tape guide pins are carried by panel 1b as also are axles 15a, 15b on which guide rollers 16a, 16b are rotatably mounted. Tape reels 9a, 9b are aligned with bores 8a, 8b provided on both panels. The panels may be transparent and the metal frames may be manufactured by zinc die casting or may be of another metal, e.g. aluminium. <IMAGE>

Description

SPECIFICATION Cassette housing This invention relates to magnetic tape cassettes, and more partrcularly,to a magnetictape cassette made of a pair of metalframes and a pair of plastic covers.

It has been proposed, for example, as disclosed in U.S. Patent No. 4,330,068, to construct a tape cassette with a metal portion to obtain improved performance characteristics. In such tape cassette, upper and lower plastic plates or panels define an outer configuration of the tape cassette housing, and a metal middle frame is positioned between the upper and lower plastic panels to define a space which accommodates the magnetic tape and the elements defining the tape running path. The metal frame can be made, for example, by aluminum die casting.

Since a portion ofthe cassette is made of metal, the total weight of such a tape cassette, and hence its inertia, is increased as compared to a cassette made entirely of plastic. Thus, when the tape cassette is played back on a reproducing apparatus, such as a tape deck, undesirable vibrations from the motor, which can affectthequalityofthe reproduced sound, can be reduced. Sincethe middleframe is madeof metal, the dimensions ofthe cassette can be more precisely determined than in the case oftape cassettes made entirely of plastic. Since the upper and lower panels defining the cassette housing are made of substantially flat plastic panels, the manufacturing process can be simplified and the precision of the molding operation can be improved as compared to all plastic cassettes.

However, in the tape cassette disclosed in the aforesaid U.S. patent,thetaperunning path is defined by metal elements, on the metal frame, sothatthe surfaces thereof must be smooth to ensure that the tape is not abraded or torn. Aspecial polishing operation is required to makethe metal surfaces smooth. In addition, the metal frame is generally made by die cast molding, and the trimming gradient needed to facilitate removal ofthe molded frame from the die must be relatively large. Hence, the tape guiding surfaces are likely to be inclined, which is undesirable.

Another drawback of a tape cassette constructed according to the aforesaid U.S. patent lies in the fact thatthethree pieces of the cassette housing are assembled or laminated in sequence and then secured together by bolts, so that it is difficult to fix the pieces togetherfirmly. As a result, the assembled parts of the cassette housing are apt to move laterally relative to each other.

According to the present invention, there is provided a cassette housing for containing magnetic tape comprising: firstand second substantially planar plastic panels; and first and second metal frame means engaging around said first and second panels, respectively, and assembled to each otherfor disposing the panels in substantially parallel relation.

The above, and other features and advantages of the present invention will become apparent from the following detailed description of an illustrative embodimentthereoftaken in conjunction with the accompanying drawings.

Fig. lisa perspective view illustrating a tape cassette in accordance with an embodiment of the present invention; Fig. 2 is an exploded perspective view of the embodiment of Fig. 1; Fig. 3 is an enlarged, plan view of the embodiment of Fig. 1 which is partially cutaway; Fig. 4 is a sectional view taken along the line IV-IV on Fig. 3; Fig. 5 is a sectional view taken along the line V-V on Fig. 3; and Fig. 6 is a part sectional, part elevational view taken along the lineVI-VI on Fig. 3.

Referring to the drawings, and initially to Fig. 1 thereof, a tape cassette according to an embodiment ofthisinvention isthere shown to generally comprise a housing 1, made up of four members or portions~ namely, a base frame la, a base panel 1b, a cover frame 1 d, and a cover panel 1 c. A length of magnetic tape 2 is disposed within cassette housing 1.One longitudinal edge of housing 1, which is hereinafter referred to as being atthe front of the housing, has a central opening 3 formed therein so that a recording and/or reproducing head (not shown), for example, of a tape cassette recording and/or reproducing apparatus (hereinafter referred to simply as a cassette tape recorder) may be inserted through opening 3 for recording and/or reproducing information signals, such as audio signals, on magnetic tape 2. The front longitudinal edge of cassette 1 also has apertures 4a, 4b, and small windows 5a, Sub therein in bilaterally symmetrical relation to the central opening 3. Capstan insertion bores 6a, 6b, and reference post insertion bores 7a, 7b, are formed in the top and bottom of cassette housing 1 adjacent the front longitudinal edge and are also in bilaterally symmetrical relation.

Magnetictape 2 is wound on a supply reel hub 9a and a take-up reel hub 9b, which are aligned with supply and tape-up reel shaft insertion bores 8a, 8b, respectively, in panels 1 and 1 c. A head back-up pad 10its disposed in back of magnetic tape 2 within central opening 3.

Referring in more detail to Figs. 2 to 6, base panel 1b is shown to be fitted into base frame 1 a, while cover panel 1 c is fitted into cover frame 1 d. In the preferred embodiment, a small amount of pressure is required to press fit base and cover panels 1 b, 1 c into frames 1 a, 1 d, respectively. Screws or bolts are used to secure the frames la and 1 dtogetherwith the panels 1 and 1 C, said four members being securely and fixedly positioned relative to each otherbytheir mutual engagement and their engagement with the respective frames.

Baseframe laandcoverframe ldare made of metal, for example, by zinc die casting. In the illustrated embodiment, base frame laand cover frame 1 d have substantially the same configuration.

Base and coverframes 1 a, 1 ddefinethe perimeter of cassette housing 1 while the flat or surface portions of the cassette housing and the tape guiding system therein are defined by base and cover panels 1 b and 1 c. The outerdimensions offrames 1 a and 1 dare approximately the same as the corresponding dimen sions of existing or standard audio tape cassettes.

The embodiment of Figs. 2-6 differs, among other ways, from prior arttape cassettes in the manner in which its reference post insertion bores 7a and 7b are defined. Circular bores 7a' and 7b' are formed in the portions of frames 1 a, 1 dcorresponding to reference post insertion bores 7a, 7b, and, as hereinafter described, receive portions of the panels 1 b, 1 c in which the square insertion bores 7a, 7bare actually formed.

Recesses 10a, 1 Ob (Figs. 2 and 3) are formed in the rear longitudinal edge of cassette housing 1 defined by frames 1 a, 1 d and are bilaterally symmetrical with respectto the center of such rear edge. As is known to those skilled in the art, erase plugs (not shown) are associated with recesses 10a, 1 Ob, and, when removed or reversed, cooperate with suitable sensors of the cassette tape recorder to prevent accidental erasure ofmagnetictape 2 contained in cassette housing 1.

Additional recesses 11 a, 11 b may be provided atthe rear longitudinal edge of cassette 1 and are bilaterally symmetrical with respect to the center of such edge to cooperate with a microswitch or other sensor (not shown) of the cassette tape recorderfor automatically determining the bias and equalization settings re quired forthe type of magnetic tape 2 included in cassette housing 1.

Asemi-circularprojectionorseatl2isprovided on each of frames la, ldandforms an arch-shaped ridge between blocks atfacing sides of additional recesses 11 a, 11 b. Arecess 1 2a (see Fig. 2) is formed in each seat 12 for receiving a cylindrical projection or post-shaped member 19 formed on the respective panel lboric,asmorefullydescribed hereinbelow.

The innersurfaces offlanges constituting side walls of frames la and 1 d have recesses 13 for receiving substantially cylindrical post-shaped abutting members or posts 20 similarly disposed on panels 1 and 1 c, as will be described more fully hereinbelow. The illustrated panels 1band 1 care of substantially the same shape, and comprise substantiallyflat portions with reel shaft insertion bores 8a, 8b formed therein.

Panels 1 b and ichave rabbited margins for interengaging with frames 1 a and 1 d, respectively, as shown on Figs. 4 and 5 and include elements which define a tape running path for magnetic tape 2, as will next be described.

Circular upstanding guide pins 14aand 14b, project form panel 1 bto define a portion of the tape running path in conjunction with guide rollers 1 6a and 16b rotatably mounted on upstanding axles 15a and 15b, respectively, also formed on panel 1 b. In the illustrated embodiment, magnetic tape 2 unwinds from supply hub 9a, past guide pin 14a, guide rollers 16a, 1 6b, guide pin 14b, and thence, to take-up hub 9b.

Guide pins 14a, 14b and axles 1 5a, 1 5b areformed only on base panel 1 b.

A boss 1 7a, 1 7b extends about each reference post insertion bore 7a, 7b and has a predetermined outside diameter to engage in bores 7a', 7b', respectively, and extends through base frame 1 a and coverframe 1 dso that the end surfaces of bosses 1 7a and 17b are flush with the outer surfaces of frames 1 a and 1 d(Figs. and 6).

A plate-shaped projection or pad 18 expands from the rear longitudinal edge of each panel 1 b, lcfor cooperating with the seat 12 ofthe respective frame 1 a, d. Each pad 18 is offset from the flat portion of panel 1 b, 1 C by an amount corresponding to the depth ofthe respective seat 12formed on frame la, it (fig 4). A semi-circular recess 18a is formed at the center of each pad 18. Acylindrical projection 19 extends perpendicularlyfrom pad 18 at the opposite sides of each panel 1 b, 1 C.Accordingly, when frames 1 a, 1 d are assembled with panels 1 b, 1 ctherebetween, each projection 19 engages, at one end, in a recess 12a in frame 1 a or id, while the other end of a projection 19 abuts againstthe other projection 19. The ends of projections 19 which abut thus serve as reinforcements against external pressures applied to panels 1 b, 1 cand tending to crush the same toward each other.

When base and coverframes ia, and base and cover panels 1 b, 1 engage each other, the other ends of projections 19 are positioned in recesses 12a of frames 1 a, d, and seats 12 of frames la, 1 dare positioned between projections 19 and arcuate recesses 1 8aformed on panels 1 b, 1 C, respectively (see Fig.

4). In such an instance,theengagementofseats 12 of frames ia, idbetween recesses 18a and projections 19 of panels 1 b, 1 cfurther reinforces cassette housing 1.

The circular abutting posts 20 are formed atthe margins of base and cover panels 1 b, 1 c and can be, for example, equally spaced apart along three sides of panels 1 b, 1 c. In the illustrated embodiment, each circular abutting post 20 engages in a respective one of the recesses 13 formed in the innersurfaces of the side walls of frames 1 a, d. Posts 20 formed on base and cover panels 1 b, 1 cextend toward each otherto abut and thereby also serve to reinforce cassette housing 1, as described above.

In the preferred embodiment, the elements defining the tape running path are formed on one panel 1band are made of the same synthetic plastic resin as panels Ib, Ic. Itisto be appreciated thatthe elements defining the tape running path have no metal parts to damage magnetic tape 2.

When cassette housing 1 is loaded in a cassette tape recorder, reference positioning posts associated with the recorder are inserted into reference post insertion bores 7a, 7b in bosses 17a, 17b. When the reference positioning parts are made of a plastic synthetic resin, bosses 17a, 1 7b of cassette housing 1 do not abrade the positioning posts since they are made of substantially the same material. For the same reason, the bosses 1 7a, 17b also do not abrade, so that the positioning accuracy of cassette housing 1 in the cassette tape recorder is maintained.

It is to be appreciated thatthe outer dimensions of cassette housing 1 can be precisely determined since frames 1 a, id, which determine the outer dimensions of cassette housing 1, are made of metal.

It is to be further appreciated thatthe tape running path is defined by a relatively complicated structure on one ofthe panels ib, icand is made of a synthetic resin or plastic, so that a trimming die with a small trimming gradient can be used in the manufacture of such structure.

In one embodiment, panels ib, icare made ofa transparent synthetic plastics resin whereby magnetic tape 2 is clearly visible.

Although frames 1 a, id have been described as being manufactured by zinc die casting, frames la, id can be made of another metal, such as aluminum.

Although a specific embodiment of the present invention has been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to that precise embodiment, and thatvarious changes and modifications may be effected therein by one skilled in the artwithoutdeparting from the spirit and scope of the invention as defined in the appended claims.

Claims (18)

1. A cassette housing for containing magnetic tape comprising: first and second substantially planar plastic panels; and first and second metal frame means engaging around said first and second panels, respectively, and assembled to each otherfordisposingthe panels in substantially parallel relation.

2. The cassette housing of claim 1; and further comprising reinforcing means for spacing said first and second panels a predetermined distance from each other.

3. The cassette housing of claim 2; wherein each of said frame means includes an upstanding edge portion substantially normal to the plane of the respective panel.

4. The cassette housing of claim 2; wherein said first and second frame means have recesses formed in inneredgesurfacesthereof, and said reinforcing means include post means projecting from said first and second panels and engaging in said recesses of said first and second frame means.

5. The cassette housing of claim 4; wherein said post means project from at least one edge of each of said first and second panels.

6. The cassette housing of claim 5; wherein said post means are equally spaced apart along said at least one edge.

7. The cassette housing of claim 6; wherein each of said panels is substantially rectangular; and said post means are spaced apart along three of the sides of each said rectangular panel.

8. The cassette housing of claim 4; wherein said reinforcing means includes interengaging means formed in said first and second panels and said first and second frame means.

9. The cassette housing of claim 8; wherein the housing is substantially rectangular and said interengaging means is positioned at a longitudinal side of the housing.

10. The cassette housing of claim 8; wherein said interengaging means includes seat means on each of said first and second frame means and having a corresponding recess formed therein, and planar pad means formed on each of said first and second panels to engage in said seat means and having an upstand ing cylindrical projection to engage in said recess of the respective seat means.

11. The cassette housing of claim 10; wherein said planarpad means is offsetfrom the plane ofthe respective panel by a distance corresponding to the depth of the respective seat means on said frame means.

12. The cassette housing of claim 1 1 ; wherein said planar pad means has a semi-circular portion.

13. The cassette housing of claim 12; wherein said seat means includes a semi-circular ridge for engagementwith said semicircular portion of the respective pad means.

14. The cassette housing of claim 4; wherein said panels have means for rotatably positioning supply andtake-up reels having magnetic tape wound thereon.

15. The cassette housing of claim 14; and further comprising tape guiding means defining a tape path in the housing and being formed on at least one of said panels.

16. The cassette housing of claim 1; wherein said panels are of a transparent synthetic plastic resin.

17. A cassette housing for containing magnetic tape, comprising: first and second metal frames to be assembled with each other for defining outer dimensions of said housing; first and second substantially planar plastic panels engageable within said first and second frames, respectively; interengaging means on said panels and frames for limiting outward movement of said panels relative to the respective frames; reinforcing means on said panels abutting against each otherwhen said frames are assembled with said panels engaged therein for preventing inward move mentofsaid panels relative to said frames; and means for securing said frames to each other in assembled relation.

18. Acassette housing constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.