Winding – tensioning – or guiding – Unwinding and rewinding a machine convertible information... – Cartridge system
Reexamination Certificate
2001-10-12
2003-08-12
Nguyen, John Q. (Department: 3654)
Winding, tensioning, or guiding
Unwinding and rewinding a machine convertible information...
Cartridge system
C242S614000, C360S132000
Reexamination Certificate
active
06604700
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tape cassette, and more specifically to a tape cassette that has a pair of tape reels capable of winding a tape, typically a magnetic tape for example, there-between into a good shape without causing winding irregularities and deformations such as wrinkles of the wound tape on the tape reels.
2. Description of the Related Art
When considering a magnetic tape for recording and reproducing video and/or audio signals among various tapes used in various technical fields, there are various systems for recording and reproducing audio and video signals, such as the &bgr;-VTR system, the VHS-VTR system or the Digital VTR system. A fundamental structure of a tape cassette to be used for each of above mentioned VTR (Video Tape Recorder) systems is basically the same, in which a tape cassette shell houses a take-up reel and a supply reel for winding the magnetic tape. As a matter of course, besides the magnetic tape as described above, there are various kinds of tapes to be wound on tape reels, such as ink ribbon tapes for printers, carrier tapes for electronic parts or the like.
A fundamental structure of each of tape reels within a tape cassette is explained with reference to FIG.
14
and
FIG. 15
, wherein
FIG. 14
shows a perspective view of a tape reel
10
used for a conventional tape cassette and
FIG. 15
shows a sectional view of the conventional tape reel
10
. An upper flange
2
and a lower flange
13
are provided at a top end and a bottom end of a hub
4
which is positioned at a center of the tape reel
10
to wind a magnetic tape in order to prevent winding irregularities or winding collapse of the magnetic tape as well as to prevent damages of end face edges of the wound magnetic tape. One of the flanges
2
and
13
(namely the lower flange
13
in case of
FIGS. 14 and 15
) is molded integrally with the hub
4
and the other flange on the other side (namely the upper flange
2
in case of
FIGS. 14 and 15
) is molded separately as another body, and this upper flange
2
is welded integrally with the upper end face of an inner cylinder
4
a
of the hub
4
. Inside the welded portion, a spring unit
6
having a metallic spherical body is held between the inner cylinder
4
a
and the upper flange
2
. As shown in
FIG. 16
, this spring unit
6
contacts with a tape reel presser
23
that is provided on an upper shell
22
of the tape cassette and depresses the tape reel
10
downward by a coil spring
24
provided between the upper shell
22
and the tape reel presser
23
. Incidentally, regarding flanges of a tape reel, a one-flange type tape reel comprises a hub and a lower flange, besides a two-flange type tape reel comprises a hub, a lower flange and a upper flange as described above.
In manufacturing the magnetic tape cassette, the magnetic tape is wound on a tape winding surface
4
q
of the hub
4
by a tape winding device called a tape winder. At this time, there easily occur winding irregularities (irregularities on the side surfaces of the wound magnetic tape) and air is considered as the cause of the winding irregularities, wherein the air is caught into between the hub
4
and the magnetic tape being wound thereon, and between the magnetic tape already wound and the magnetic tape being wound up thereon. Besides, there is the case where the magnetic tape is deformed (for instance, creases in the width direction of the magnetic tape that is slightly piled up). These problems tend to easily occur on the inner side of the wound tape.
FIG. 17
shows a plan view of the lower flange
13
of the tape reel
10
used in the conventional tape cassette (hereinafter abbreviated as the tape reel
10
), and illustrates the inner surface thereof. As shown in
FIG. 17
, on the inner surface of the lower flange
13
,
12
of concave portions
18
are formed as to extend in a radial direction at even angle intervals of 30 degrees. These concave portions
18
are provided so as to escape the air that is caught in between the magnetic tape at the time of winding up thereof as soon as possible, and each of the concave portions
18
is formed gradually wider as approaching to the outer periphery. However, even in the tape reel
10
having such concave portions
18
on the lower flange
13
, generation of winding irregularities has not been prevented substantially due to inadequate or improper escape of the air. Furthermore, by escaping the air being caught together with the running magnetic tape, the pressure given from outer periphery of the wound magnetic tape to inner side of the wound magnetic tape is increased. Accordingly as shown in
FIG. 18
, at the inner side where a winding condition of the magnetic tape T is loose, the surface of the wound magnetic tape forms moderate wavy bumps and dips, which causes problems of [crease] or [looseness].
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-described problems, and when winding up a tape, one aspect of the present invention is to provide a tape cassette having tape reels capable of winding up the tape uniformly without causing winding irregularities and without incurring deformation.
The above-described problems may be solved by a structure of an aspect of the present invention, and means of solving the problems are described in detail hereunder.
A tape cassette according to one aspect of the present invention includes at least one tape reel having a flange at a hub unit on which a tape is wound. Further in the tape cassette of the invention, a flange of the tape reel has at least one concave portion to escape the air formed within the inner surface of the flange, and at least one of such tape reels is included within a tape cassette shell. The concave portion provided on the inner surface of the flange becomes larger at a circumferential cross-sectional area as approaching to the inner side nearer to the hub unit.
In such tape cassette, each of the concave portions of the flanges of the tape reel has the larger circumferential cross-sectional area as approaching to the inner side nearer to the hub unit, so that an amount of escaped air becomes more as approaching to the inner side. Accordingly, in a state that the tape is wound up, an amount of the air caught in between the tape may become less as approaching to the inner side, and more as approaching to the outer periphery, so that a pressure of the wound magnetic tape at the outer periphery may be reduced and may not reach the inner side, and the magnetic tape at the inner side may not be deformed when wound up. At the same time, an amount of air being caught by the concave portions may be restrained so that slide to the width direction between the overlapped magnetic tape may be inhibited with a result that winding irregularities may be effectively prevented and a good shape may be maintained.
In the tape cassette according to the present invention, the concave portions of the flange of the tape reel may have basically constant depth to the lateral direction, and may have broader width as approaching to the inner side nearer to the hub unit. In such tape cassette, mechanical strength of the tape reel may not be decreased by the concave portions, and an amount of the escaped air may be increased as approaching to the inner side and the wound form of the tape becomes a proper wound form.
In the tape cassette according to the present invention, the concave portions may be such that a cross-sectional form to the radial direction may have substantially constant depth. In such the tape cassette, an amount of escaped air may be set up by the width of the concave portions.
In the tape cassette according to the present invention, the concave portions may be such that a cross-sectional form to the radial direction may be deeper as approaching to the inner side. In such the tape cassette, an amount of escaped air may further be increased gradually as approaching to the inner side to provide even more proper wound form.
In the tape cassette ac
Kananen Ronald P.
Nguyen John Q.
Rader & Fishman & Grauer, PLLC
Sony Corporation
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