JPH0313919Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape hub for an audio cassette.

Conventionally, as tape hubs for audio cassettes, the ones shown in FIGS. 1 and 2, for example, are known. In FIG. 1, 1 is a tape hub made entirely of plastic, 2 is an outer circumferential portion defining a tape winding surface 2a, and 3 is a web portion that supports the outer circumferential portion 2. As shown in FIG. According to this configuration, the tape hub 1 is released from the mold by poking the web portion 3 with a protruding pin, so the web portion 3 is configured to have a thick wall (the second (see figure). Therefore, the tape winding surface 2a of the outer peripheral part 2 after forming by the thick web part 3
However, there was a drawback that sink marks were generated as shown by the chain line in FIG. 2, which adversely affected the running of the tape.

In view of the above points, the purpose of the present invention is to provide a tape hub for an audio cassette that prevents the occurrence of sink marks on the tape winding surface while maintaining good mold releasability. An annular web part that is tapered toward the wall and supports the outer periphery that defines the tape winding surface, and is arranged alternately at appropriate intervals on both sides of the web part. This object is achieved by a tape hub for an audio cassette which is characterized in that it includes a plurality of radially extending reinforcing ribs.

The present invention will be described below with reference to an embodiment shown in the drawings. In FIG.
Cross-sectional view, e is rear view, f is bottom view, g is front view b
BB cross-sectional views are shown in each figure. Note that the left side view is the same as the right side view. Reference numeral 11 denotes a tape hub for an audio cassette according to the present invention, 12 an outer peripheral portion defining a tape winding surface 12a and having a constant thickness in the axial direction, and 12' an inner peripheral portion having a constant thickness in the axial direction. The peripheral part 13 is a web part that supports the outer peripheral part 12, and is formed integrally with the inner peripheral part 12' so as to taper and become thinner toward the outside in the radial direction. 14 is a plurality of radially extending reinforcing ribs formed on the surface of the web portion 13 in the front view b, and 15 is a radial reinforcing rib formed on the back surface of the web portion 13 in the front view b, that is, on the front side in the rear view e. A plurality of reinforcing ribs 14 and 15 are provided integrally with the web portion 13 and are substantially alternately arranged at appropriate intervals in the circumferential direction.

The present embodiment is constructed as described above, and the web portion 13 supports the outer peripheral portion 12 at its thin outer end portion. If the thickness is 1/2 or less of the wall thickness of the outer peripheral part 12, sink marks will not occur on the tape winding surface 12a of the outer peripheral part 12. In addition, reinforcing rib 1
4 and 15 are connected to the web portion 13 and the outer circumferential portion 12, the supporting strength of the outer circumferential portion 12 by the web portion 13 is maintained at approximately the same level as the supporting strength by a conventional thick web. Furthermore, when releasing the mold, good mold releasability can be maintained by, for example, poking the back side of the reinforcing rib 14 with a protruding pin as indicated by the arrow in FIG. 3g.

As described above, according to the present invention, the web portion is formed so as to become thinner in a tapered shape toward the outside in the radial direction, and reinforcing ribs are arranged alternately on both sides of the web portion, so that after molding, Since virtually no sink marks occur on the tape winding surface at the outer periphery, it is very preferable from the point of view of tape running performance, and the support strength and mold releasability of the outer periphery by the web part do not decrease, and the same as before. Furthermore, during use, the rotation of the audio cassette tape hub can be more clearly indicated by the reinforcing ribs, making it extremely effective.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of a conventional tape hub for an audio cassette, FIG. 2 is an enlarged sectional view taken along the line of FIG. 1, and FIG. 3 is a diagram showing an embodiment of a tape hub for an audio cassette according to the present invention. a is a plan view, b is a front view, c is a right side view, d is a sectional view along A-A in front view b, e is a rear view, f is a bottom view, and g is a sectional view along B-B in front view b. Each is shown. 1, 11... Tape hub for audio cassette, 2, 12... Outer periphery, 2a, 12a... Tape winding surface, 3, 13... Web part, 14, 15
...Reinforced ribs.

Claims (1)

[Scope of utility model registration request] An inner circumferential portion 12' having a plurality of engaging claws protruding from the inner circumferential surface to engage with the reel drive shaft and having a constant thickness in the axial direction, and a tape winding surface 12a.
In the tape hub for an audio cassette, the tape hub for an audio cassette is constituted by an outer circumferential portion 12 formed with a constant thickness in the axial direction defining a The web portion 13 is separated by appropriately spaced reinforcing ribs 14 and 15, and is connected to the inner and outer circumferential portions of the inner circumferential portion 12' and the outer circumferential portion 12 at approximately the center of the axial thickness of the inner circumferential portion 12' and the outer circumferential portion 12. The outer circumferential portion 12 extends integrally with the connecting portion from the axial thickness of the connecting portion with the outer circumferential portion 12 so as to continuously become thinner in the radial direction outward in a tapered cross-sectional shape. The reinforcing ribs 14 and 15 are connected to the web portion 1.
The inner circumferential portions 12' are arranged alternately at appropriate intervals on both sides of 3.
and a plurality of ribs extending in the radial direction that are integrally formed and thinner than the wall thickness of the outer peripheral portion 12.