JPS6327348Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a spool mechanism for a tape cassette that incorporates a pair of spools for winding an end-ended magnetic tape, and winds the tape by pulling the tape when the tape is driven. This prevents abnormal noises that occur at the engagement part between the hub and the hub inlet that drives the hub, and also prevents the hub from moving in frames relative to the hub in, thereby reducing uneven tape winding (steps occur on the upper and lower sides of the winding line). The present invention provides a spool mechanism that prevents damage to the tape by eliminating the need for a spool mechanism and that is easy to assemble.

Furthermore, the present invention relates to an improvement of the invention shown in Utility Model Application No. 57-33645 and Utility Model Application No. 57-33646 filed on March 9, 1988. That is, in the embodiments of both prior applications, as shown in FIGS. 1 and 2, the spool 2 of the cassette case 1 is pressed toward the reel shaft hole 4 through the leaf spring 3, and the driving reel shaft 5 is fitted into the spool 2 of the cassette case 1. The spool 2 is configured to be able to rotate upwardly against the leaf spring 3, and to be prevented from rotating when the drive reel shaft 5 is detached.

That is, the spool 2 consists of a cap-shaped inner cylinder 6 and a cap-shaped outer cylinder 7 into which the inner cylinder 6 is fitted. The inner cylindrical body 6 has a bearing portion 8 for the drive reel shaft 5 formed on its inner periphery, and a projection 9 that makes point contact with the leaf spring 3 on its upper portion.
Moreover, the inner cylindrical body 6 has an edge bottom surface 1 on the outer periphery bottom edge of the cylindrical body 6.
Tongue pieces 11, 11, 11 having the same surface as 0 are formed. The outer cylindrical body 7 has a magnetic tape T wound around its outer periphery, and the inner cylindrical body 6 is fitted into the outer cylindrical body 7. A hole is formed in the upper part of the outer cylindrical body 7 so that the protrusion 9 of the inner cylindrical body 6 comes into contact with the leaf spring 3. 12 have been established. In addition, the outer cylinder body 6
forms a frame 13 that slightly protrudes on the bottom edge of the outer periphery, and the tongue pieces 11 on the bottom edge of the inner cylinder 6 are formed on the bottom edge of the inner periphery.
11, 11 to transmit the rotation of the inner cylinder body 6 by the drive reel shaft 5 to the outer cylinder body 7.
4 and 14 are formed. Engagement elements 15, 16, .
is formed. Further, a projecting frame 17 is formed on its outer periphery to hold the outer peripheral bottom edge frame 13 of the outer cylindrical body 7 in a loosely fitted manner.

Thus, the drive reel shaft 5 is connected to the bearing portion 8 of the inner cylinder body 6.
When inserted, the inner cylinder 6 moves upward against the leaf spring 3. As the drive reel shaft 5 rotates, the tongues 11 of the inner cylinder 6 fit into the fitting parts 14 of the outer cylinder 7, so the rotation of the inner cylinder 6 by the reel shaft 5 causes the outer cylinder 7 to The magnetic tape that is transmitted and wound around the outer periphery of the outer cylindrical body 7 is wound up. At this time, the outer periphery bottom edge frame 1 of the outer cylinder body 7
3 fits within the height of a protruding frame 17 on the bottom of the cassette case, and an appropriate gap between the protruding frame 17 and the frame 13 prevents the eccentricity that occurs between the reel shaft 5 and the bearing portion 8 of the inner cylinder 6. Can be absorbed.

In addition, when the drive reel 5 is not fitted into the bearing part 8 of the inner cylinder body, the inner cylinder body 6 is pressed in the direction of the reel shaft hole 4 via the leaf spring 9, so the tongue piece of the inner cylinder body 6 11...The engagement element 15... formed on the bottom surface and the engagement element 16... on the outer periphery of the reel shaft hole 4 engage with each other to prevent the inner cylinder body 6 from freely rotating. At this time, the outer cylindrical body 7 has the tongue pieces 11 of the inner cylindrical body 6 at this fitting portion 1.
4, the outer cylinder 7 also fits into the inner cylinder 6.
Similarly, free rotation is prevented. That is, when not in use, the outer cylindrical body 7 around which the magnetic tape is wound is prevented from freely rotating, thereby preventing the tape from loosening.

The embodiment shown in the prior application is as described above, and the diameter of the cylinder around which the magnetic tape is wound is made smaller than the diameter of the drive reel shaft head, so that the winding diameter of the tape can be made large, and the tape can be wound with a large diameter. This allows recording and reproduction to be performed over a longer period of time.

However, in the above configuration, the rotational connection between the inner cylindrical body 6 and the outer cylindrical body 7 is achieved by connecting the tongue pieces 11 to the fitting portions 14.
. . . only the bottom edges of the cylindrical bodies 6 and 7 forming the cylindrical bodies 6 and 7. Therefore, since both cylindrical bodies 6 and 7 are loosely fitted, when the inner cylindrical body 6 is rotated by the reel shaft 5, the bottoms of both cylindrical bodies 6 and 7 are engaged. The outer cylindrical body 7 rotates while moving piece by piece while remaining loose. This causes uneven winding of the tape as described above.

Further, as shown in FIG. 3, especially on one take-up spool 2, the tongue piece 11 and the fitting part 14 come into contact on the line l connecting the contact point 18 of the magnetic tape T and the center of the inner cylinder 6. When there is a part 19, the rotational moment of the inner cylinder 6 acts only in the direction 20 parallel to the tension direction 21 of the tape T, but it rotates further to the state shown in FIG. When the contact portion 19 separates from the line l connecting the centers of the cylinder 6, the outer cylinder 7
is drawn toward the center 22 of the inner cylinder 6 by the tension 21 of the tape T. At this time, the abutting portion 19 suddenly moves, causing a clicking sound that occurs three times per rotation in the case of engagement at three locations as shown in the figure. In the worst case, if you include the sounds that occur when returning from the state shown in FIG. 4 to the state shown in FIG. 5, abnormal noises will occur six times per revolution. Such sounds are harsh on the latest tape recorders and degrade the product value. The present invention overcomes the above drawbacks.

An embodiment of the present invention will be described below with reference to FIGS. 5 and 6. In the figures, parts that are the same as those in the earlier application will be described using the same numbers. Further below, the inner cylindrical body 6
The explanation will be made by replacing "hub-in 6" with "hub-in 6" and "outer cylinder body 7" with "hub 7." The hub-in 6 is provided with recesses 23 along the height direction of the outer periphery of the cylinder. Also, the magnetic tape with an end
The hub 7 around which the cylinder is wound is provided with a convex portion 24 that engages with the concave portion 23 of the hub in 6 along the height direction of the inner circumference of the cylinder. That is, these hub-in 6 and hub 7
The height of the uneven portions 23 and 24 corresponds to the width of the tape T. Further, the concave portions 23 have large angles θ, θ with respect to the line l toward the center of the hub in 6 on the surface where the convex portion 24 of the hub 7 comes into contact with the tape T.
resistance surface 25 of the convex portion 24 in the tensile direction 21 of
25.

Thus, the hub-in 6 and the hub 7 have uneven portions 23 and 24 formed in the height direction on their inner and outer peripheries during rotation.
... engages in the height direction, and engages and rotates in the height direction, that is, the tape width, thereby eliminating the piece motion of the hub 7 and preventing the tape from winding in stages. Also, the surface of the recess 23 formed on the outer periphery of the hub in 6 that is in contact with the convex part 24 of the hub 7 has a large angle θ, θ with respect to the line l toward the center of the hub in 6.
Even when the resistance surface 2 of the convex portion 24 is rotated by α angle as shown in FIG.
5 and 25, the abutting portion 19 as shown in FIG. 4 does not move, and the generation of abnormal noise can be prevented.

In addition, in the case of the present invention shown in FIGS. 5 and 6, the bottom of the hub and the hub-in, as shown in FIGS. 3 and 4, do not contact the tongue pieces 11 and the fitting part 14, and maintain a gap between them. It rotates. That is, this bottom part does not cause abnormal noise or uneven rotation.

As is clear from the above embodiments, the present invention has a cap-shaped hub in 6 that covers the drive reel shaft head 5.
and a hub 7 on which the magnetic tape T is wound around the outer periphery of the hub-in 6 with a slight play gap, and the tape T is wound at a height between the inner periphery of the cylinder of the hub 7 and the outer periphery of the hub-in 6 cylinder. The uneven part 2 corresponds to the
3, 24, the uneven portion 23 has a contact portion 19 on a line connecting the contact point 18 of the tape T guided to the hub 7 and the center of the hub in 6;
Convex portions 2 are formed on the surfaces 25, 25 of the concave portion 23 to convert the rotational moment of the hub in 6 into a direction parallel to the tensile direction 21 of the tape T when the hub in 24 rotates by α angle.
4, it eliminates the hub movement,
It is possible to prevent damage to the tape due to uneven winding of the tape, and it is also possible to eliminate abnormal noise generated at the engaging portion of the hub and the hub-in.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the cassette showing the spool portion of the earlier application, Fig. 2 is a bottom view of only the spool portion of the previous drawing, Figs. 3 and 4 are explanatory views of the enlarged effect of the previous drawing, and Fig. Figures and Figure 6 are A- in Figure 1 showing the earlier application.
FIG. 7 is an enlarged cross-sectional functional explanatory view of the present invention corresponding to the A-line cross-sectional view, and is an enlarged view of the main part of the previous figure. 5... Drive reel shaft head, 6... Hub in (inner cylindrical body), 7... Hub (outer cylindrical body), 21... Tape tensioning direction, 23... Concave portion, 24... Convex portion, 25...
resistance side.

Claims (1)

[Scope of utility model registration request] It consists of a cap-shaped hub in 6 that covers the drive reel shaft head 5, and a hub 7 that wraps a magnetic tape T around the outer periphery of the hub 7 with a slight play gap. In the structure in which uneven parts 23 and 24 are formed on the outer periphery of the six cylinders and correspond to the winding height of the tape T, the tape contacts the line connecting the contact point 18 of the tape T guided to the hub 7 and the center of the hub in 6. The uneven portion 2 having a portion 19
When 3 and 24 rotate by α angle, the hub in 6
1. A spool mechanism for a magnetic tape cassette, characterized in that a convex portion 24 is engaged with surfaces 25, 25 of a concave portion 23 for converting the rotational moment of the tape T into a direction parallel to a pulling direction 21 of the tape T.