JPS6336557Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape cartridge provided with a tape guide perpendicular to the inner surface of the case.

FIG. 1 shows a general magnetic tape cartridge that connects an upper case 1 and a lower case 2. Inside, left and right reels 3 and 4 are rotatably arranged.
Tape guides 5 are formed on the feeding and winding sides of the tape, respectively. In addition, the corners and center of the upper and lower cases 1 and 2 are
A screw fixing part 6 for positioning and joining is provided. In such a magnetic tape cartridge, the structure of the tape guide 5 was as shown in FIG. That is, on the inner surfaces of the upper case 1 and the lower case 2, tapered bosses 7 and 8 with tapered surfaces 7a and 8a from the base to the tip are protruded at positions facing each other, and the bosses 7 and 8 have cylindrical shapes. Fit the tape guide 5 of the shape, and screw the screw 9 between both bosses 7 and 8 from the outside of the lower case 2, and by tightening the screw 9, the upper and lower end surfaces of the tape guide 5 are connected to the upper and lower cases 1 and 2. The tape guide 5 was held perpendicular to the inner surfaces of the upper cases 1 and 2 by being held between the inner surfaces of the upper cases 1 and 2.

However, in the above conventional example, since the root portions of the bosses 7 and 8 are tapered surfaces 7a and 8a, the contact between the inner circumferential wall of the tape guide 5 and the outer circumferential wall of the bosses 7 and 8 is approximately linear contact, and the tape guide 5 The holding in the vertical direction was mainly due to the clamping force between the inner surfaces of the upper and lower cases 1 and 2. In addition, the tapered surfaces 7a, 8a
It is very difficult to form the tape guide 5 with high precision at its base, and a slight positional deviation makes it very difficult to hold the tape guide 5 vertically.

In view of the above-mentioned points, the present invention aims to ensure vertical retention of the tape guide through simple molding process. It is characterized by the provision of strict regulations.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is an enlarged cross-sectional view showing the main parts of the present invention. The boss 7 provided on the inner surface of the upper case 1 has a tapered shape with a tapered surface 7a for the most part, and the base of the boss 7 is A cylindrical regulating surface 7b vertically rising from the inner surface is formed. Further, the center of the boss 7 is provided with a receiving hole 7c into which a screw 9 is screwed. On the other hand, the boss 8 protruding from the inner surface of the lower case 2 also has a tapered surface 8a and a regulating surface 8b like the boss 7, and has an insertion hole 8c in the center for inserting the screw 9 from the outside. There is. A cylindrical tape guide is tightly fitted into the upper and lower vertical regulating surfaces 7b and 8b. The inner wall of the tape guide 5 is formed vertically over almost the entire length, and the front end,
A chamfer 5a is formed at the rear end opening to facilitate attachment of the tape guide 5 to the bosses 7 and 8. However, as shown in FIG. 3, this chamfer 5a must be shorter in the vertical direction than the regulating surfaces 7b, 8b of the bosses 7, 8.

To install the tape guide 5, attach the upper and lower bosses 7,
8, the tape guide 5 is fitted to the lower case 2, the screw 9 is inserted through the insertion hole 8c of the lower case 2, and the screw 9 is screwed into the receiving hole 7c of the boss 7. At this time, the tape guide 5 smoothly fits into the bosses 7 and 8 due to the chamfer 5a of the tape guide 5, and the vertical wall surface of the tape guide 5 inward from the chamfer 5 and the bosses 7 and 8 The regulating surfaces 7b, 8b are tightly fitted, and the tape guide 5 is held in the vertical direction along the regulating surfaces 7b, 8b.

In this embodiment, a chamfer 5a is formed at the opening end of the tape guide 5, but as shown in FIG. You can also do that. In addition, if the chamfer 5a is not formed, the tape guide 5
The inner edge of the opening end and the lowest part of the regulating surfaces 7b and 8b are
Since tight fitting becomes difficult due to burrs and other factors, annular relief grooves 7e and 8e may be formed at the lowest parts of the regulating surfaces 7b and 8b. Further, although a tap-in screw is used as the screw 9, it may be a dowel pin or the like.

As described above, the present invention has a regulating surface perpendicular to the case surface into which the tape guide is tightly fitted, at the base of the boss of the upper and lower cases. The tape can be held perpendicularly to the case at all times, making it possible to stabilize the running of the tape. Furthermore, since the regulating surface is perpendicular to the case surface, it is easier to achieve dimensional accuracy through molding than with a tapered surface, which is extremely advantageous for mass production.

[Brief explanation of the drawing]

Fig. 1 is an explanatory plan view showing the entire general magnetic tape cartridge, Fig. 2 is an enlarged sectional view of the main part of the conventional example, Fig. 3 is an enlarged sectional view of the main part of the present invention, and Fig. 4
The figure is a sectional view showing another embodiment of the present invention. 1... Upper case, 2... Lower case, 5... Tape guide, 7, 8... Boss, 7b, 8b... Regulatory surface.

Claims (1)

[Scope of utility model registration request] In a magnetic tape cartridge, a boss is formed facing each other on the inner surface of the upper case and the inner surface of the lower case, and a cylindrical tape guide is fitted to the boss. A magnetic tape cartridge comprising a regulating surface perpendicular to the case surface that tightly fits into the tape guide at the base of the magnetic tape cartridge.