Winding – tensioning – or guiding – Unwinding and rewinding a machine convertible information... – Cartridge system
Reexamination Certificate
1999-06-03
2001-03-20
Matecki, Katherine A. (Department: 3653)
Winding, tensioning, or guiding
Unwinding and rewinding a machine convertible information...
Cartridge system
C242S611200
Reexamination Certificate
active
06202951
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tape cartridge, and more particularly to an enforcing rib provided to a hub pawl of a tape winding hub.
2. Description of the Related Art
As shown in
FIG. 1
, a tape cartridge in a prior art is constructed so that plastic (generally, high-impact polystyrene) hubs
12
around which a tape
11
is wound are freely rotatably located on respective driving shaft insertion holes
13
at the right and left sides in a main body case
10
. Each of both the ends of the tape
11
is hooked and coupled to a part of each outer periphery of the right and left hubs
12
by a cramping piece
14
, and the tape
11
is drawn from one hub
12
to the front face of the main body case
10
and wound by the other hub
12
.
The hub
12
has a hub hole
15
at the center thereof, and a plurality of hub pawls
16
are integrally projected from the inner peripheral surface of the hub hole
15
in the central direction so as to be spaced from one another at predetermined intervals.
The hub pawl
16
is designed in a substantially cylindrical shape of about 1.5 mm in diameter and about 1 mm in length, and it is extremely smaller as compared with the size, thickness, etc. of the overall hub
12
. Therefore, fast feeding or rewinding operation by a recent tape recorder imposes a large impact load on the hub pawls
16
, and excessive stress is applied to the bases of the hub pawl
16
, so that such a problem as damage or the like may occur. Particularly since there frequently occurs such a case that a user carries a tape cartridge on the road when the user goes outdoors, when a drop impact or the like is applied to a tape cartridge while the tape cartridge is accommodated in an accommodation case, a hub rotation stop member at the accommodation case side and the hub pawls
16
collide against each other, and the hub pawls
16
may be damaged at the base portions thereof.
JP-A-60-51685U previously proposed a device of a countermeasure of preventing the damage of the hub pawls
16
as described above. In this device, as shown in
FIG. 2
, the base portion of the hub pawl
16
in the rotational direction is provided with ribs
18
each comprising a rounded R-surface
17
. By forming the R-surface
17
as described above, the concentration of the excessive stress due to the impact load which is applied to the hub pawls
16
in the rotational direction can be avoided, and the strength can be enhanced, so that the damage preventing effect of the hub pawls
16
can be expected.
However, in case of the hub pawl
16
having the ribs
18
having the R-surface
17
as described above, when the hub
12
is manufactured, it is necessary to process the place of a die corresponding to the R-surface portion of the hub pawl in a minute and complicated three-dimensional shape, and it is difficult or impossible to perform the processing by using equipment such as an electric discharge machine or the like. Therefore, there is a problem that the cutting work must be manually carried out on the place.
In order to solve this problem, there is known JP-A-62-80280U. In this device, as shown in
FIGS. 3 and 4
, the rib
19
provided to the base of the hub pawl
16
is designed in a simple two-dimensional shape to have an R-surface
20
. That is, as shown in
FIG. 4
, the rib
19
has the R-surface
20
provided in the rotational direction of the hub
12
, and side surfaces
22
which are crossed to the R-surface
20
through the ridgelines at both the sides of the R-surface
20
, and the R-surface
20
is designed to have the same curvature in the pawl peripheral direction W. The rib
19
of the hub pawl
16
is designed in such a two-dimensional simple shape as described above, so that the electric discharge machining to form a die can be performed and the die processing can be facilitated.
However, even when the R-surface of the rib provided to the hub pawl in the prior art described above is designed in a simple two-dimensional shape, the shape of an electrode required for the electric discharge machining to form a die must be processed in conformity with the shape of the rib. Therefore, there is a problem that the shape of the electrode is complicated.
Accordingly, there is a problem that a rib must be designed in such a shape that an electrode for the electric discharge machining used to process a die for the rib provided to the hub pawl is simple.
SUMMARY OF THE INVENTION
In order to solve the above problem, a tape cartridge according to the present invention in which a hub for winding a tape therearound is accommodated, is characterized in that the hub comprises a hub hole penetrating through the center position, a plurality of cylindrical hub pawls projected from the inner peripheral surface of the hub hole, and ribs having slant surfaces which are provided to the base portions of the plural hub pawls in the hub rotational direction, the slant surfaces of the ribs are designed in a three-dimensional convex shape which is swollen from the cylindrical hub pawls, and further the ribs having the three-dimensional swollen convex shape are designed in an arcuate shape which is inclined with respect to the cylindrical hub pawls.
Further, each of the arcuate ribs inclined with respect to the cylindrical hub pawls has a slant angle of 30 degrees to 70 degrees, and the rib height dimension which comprises the cross point between the slant surface and the hub pawl, and the tangential line of the hub hole is set to 0.37 mm to 0.47 mm.
By adopting the above structure, the processing becomes possible merely by designing an electrode used when the electric discharge machining of a die is performed into a simple shape such as a cylindrical shape, a semi-cylindrical shape or the like, so that the power saving when forming the electrode for the electric discharge machining can be achieved and also the cost can be reduced.
REFERENCES:
patent: 4515331 (1985-05-01), Stumpfi et al.
patent: 4541587 (1985-09-01), Stumpfi et al.
patent: 4679109 (1987-07-01), Okamura et al.
patent: 4715558 (1987-12-01), Fair et al.
patent: 661 609 (1987-07-01), None
patent: 0 051 145 (1982-05-01), None
patent: 60-051685 (1985-04-01), None
patent: 62-080280 (1987-05-01), None
Frommer William S.
Frommer Lawrence & Haug LLP.
Matecki Katherine A.
Ryan Matthew K.
Sony Corporation
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