Note: Descriptions are shown in the official language in which they were submitted.
20~1937
INTEGRAL REEL SPRING~REMOVABLE DUST DOOR COMBINATION
B~ACKGROUND OF THE INVENTION
This invention relates to tape cassettes and, more
particularly, to a reel leaf spring of a video tape cassette
cover for rotatably supporting the hubs o~ tape reels in the
tape cassette, and a removable dust door which cooperates
therewith.
A conventional video tape cassette includes a base and
a cover, each made of plastic. The assembled base and cover
accommodate a pair of tape reelc~ each including a hub for
winding magnatic recording tape therearound.
The sassette also usually includes a saparate reel leaf
spring, i.e., a spring stamped from a flat piece of metal or
alloy, such that arms are bent to extend from both sides of
a central, ~lat portion of the spring, as described in
Assignee's U.S. Patent No. 4,662,S7~, entitled "Coined Reel
Leaf Spring for a Video Tape Cassette". The central, flat
portion of the reel leaf spring includes holes to receive
projections formed on a central planar area of the underside
of the cover. The free ends of the projections are swedged
or post formed to extend around the holes and permanently hold
the leaf spring relative to the cover.
With the arrangement described above, when the cover
including the reel leaf spring is assembled with the base,
both of the free ends of the arms of the spring contact the
hubs of the respective tape reels and bias the tape reels
downwardly, so that the tape reels are rotatably retained in
~0~1~37
position with adequate pressure to interface a tape
player/recorder. That is, when the cassette is placed in the
tape player/recorder, spindles of the tape player/recorder
enter the hubs and lift the reels against the force of the
spring. When the cassette is no~ in the tape player/recorder,
the spring pushes the reels against the base and the reels are
prevented from rotating by a reel lock device well known in
the art. Alternatively, teeth on the cassette base could
cooperate with teeth on the reel to lock the reels, as
described in A-~signee's co-pending U.S. Patent Application
Serial No. 07/471,648, entitled "Static Tape Cassette Reel
Lock".
Assembly of this spring is relatively labor intensive.
That is, the springs mus~ be stamped and bent, the holes must
be accurately formed; the corresponding projection~ must be
molded on the cassette cover, the spring must be mounted so
that the holes properly receive the projections, and the
projections must be post formecl. All of these steps, of
course, rai~e the cost of the entire cassette.
Further, after positioning the spring on the cover, but
before permanent connection, it is possible that the spring
could be dislocated relative to the projections while
progressing in the assembly line.
Moreover, with cassettes, as with all plastic consumer
goods, a need exists to find ways to re-cycle the products
20~1~37
instead of merely depositing them in land fills. Of course,
the more difficult and expensive it is to separate different
materials such as metal and plastic, in this case the spring
from the cassette cover, the less incentive there is to re-
cycle.
The Assignee's cop~nding U.S. patent application Serial
No. 4~8,428, entitled "~eel ~eaf Spring/Cassette Cover
Combinations and Methods for Assembly" describe~ a reel leaf
spring which is removably cam fit or pre~s fit between
projections or ra~ps formed on the cassette cover. This
structure facilitates assembly and re-cycling by making it
easier to install and remove the metal reel leaf spring
relative to the cassette cover. Further, Assignee's cop~ending
application Serial No. entitled "Wire Reel. Leaf
Spring/Cassette Cover Combination and Methods for Assembly"
describes a metal wire reel leaf spring which also shares
these attributes.
However, the reel leaf springs discussed above still are
not the most cost-efficient, nor do they lend themselves to
the easiest fabrication and re-cycling.
A conventional cassette further includes a pivotable,
spring biased dust door which, when closed, pro~ec~s the tape
from dust, contact, etc. An example of such a dust door is
described in Assignee's U.S. Patent No. 4,533,093, entitled
"Tape Cassette Dust Door Spring Assembly and Method for
20~Lg37
Assembling Same~" When the door i5 openedt usually
automatically by a tape player/recorder when the cassette is
placed therein, the magnetic head of the player/recorder can
gain access to the tape.
Incorporating such a dust door in a cassette requires
molding of the door, formation of a spring, installation of
the spring on the dust door, loading of th~- spring against the
cassette, producing, installing and loading a dust door latch
and related spring, and biasly capturing the dust door between
the basa and cover as the base and cover are mated during
assembly. This number of steps is not very cost-efficient.
Further, there is always the chance that the parts, such as
the dust door spring, could become misaligned during
manufacture, shipping, handling or use, and fail to properly
operate.
Finally, none of the prior art dust doors in any way
cooperates with the reel spring to improve the resilient life
thereof.
Assignee's co-pending U.S. Application Serial No.
610,5~S, entitled "REMOVABLE DUST DOOR INCO~PORATING TAPE REEL
LOCK" describes a removable dust door, but same also does not
cooperate with a reel spring.
Thus, the dust doors discussed above still are not the
most cost-efficient, nor do they lend themselves to the
easiest fabrication and re-cycling and they fail to combine
2~ L937
in any way with the reel spring.
SUMMARY OF THE INVENTION
Accordingly, it i5 a purpose of the present invention to
provide a reel spring and dust door contributing to reducing
overall production costs of the tape cassette.
It is another purpose of the present invention to provide
a reel spring and dust door which are more ecological than
conventional correspondinq members by promoting material and
energy conservation.
It is another purpose of the present invention to provide
a tape cassette requiring Pewer parts than conventional tape
cassettes.
It is another purpose of the present invention to combine
two separate members already used in a cassette into a single,
integrally molded member capable of performing the functions
of the previous two separate members.
It is another purpose of the present invention to provide
a dust door requiring no assembly of parts lnto a video
cassette or separate biased mounting.
It i5 another purpose of the present invention to provide
a reel spring requiring no assembly of parts into a video
cassette.
It is another purpose of the present invention to combine
the operations of a reel spring with a dust door.
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2 ~ 3 7
It is another purpose of the present invention to provide
a reel spring~removable dus~ door co~bination for a video tape
cassette which lacks moving or wor~ing parts, except
cooperation between the dust door and the reel spring, to
improve reliability.
To achieve the ~oregoing and other purposes of the
present in~ention and in accordance with the purposes of the
invention, there is provided a pair of reel springs molded
integrally o~ the cassette cover~ The reel springs are molded
inwardly at an angle to the plane o~ the cover. Once the
cover is mated with the base, with tape reels therebetween,
the springs push the tape reels against the cassette base,
where the tape reels are locked against rotation by other
means. There is also provided a removable dust door which has
formed thereon an extension having a pair of spaced
projections. When the dust door is positioned on the
cassette, the extension abuts the cassette cover and tha
projections extend through corresponding openings formed
around the reel springs to abut these springs and hold the
tape reels against the cassette base. Thus, no spring fatigue
i5 realized until the door is removed. When the dust door is
manually removed from the cassette, the projections disengage
from the reel springs, and the tape is exposed for access by
the tape player/recorder.
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~06~937
~RIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and
constitu~e a part of ~he specifica~ion, illustrate embodiments
of the inve~tion, and, together with the description, serve
5to explain the principles of tha in~ention.
FI&. 1 is a top view of a tape cassette according to the
presant invention, illustrating particularly integral reel
springs formed in the cover, but with a conventional dust
door.
10FIG. ~ is a bottom view of the reel springs formed in the
cover.
FIG. 3 is a side, cross-sectional view of one of the
integrally formed reel springs biased against the top of a
tape reel hub.
15FIG. 4 is a top view of the tape cassette cover according
to the present inventlon, illustrating particularly a
removable dust door combined with the integral ree1 springs.
FIG. ~ is a perspective view of the dust door being
removed~assembled relative to the cover.
20FIG. 6 is a side, cross-sectional view of a hook formed
on the dust door extension engaged in an opening formed in the
tape cassette cover.
FIG. 7 is a side view of the removable dust door
assembled on the cover.
25FIG. 8 is a top view of the removable dust door.
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206~37
FIGo 9 is a front view of the removable dust door.
FIG. 10 is a perspective view of a removable member used
with the f irst embodiment described above.
DESCRIPTION OF THE PREFE~RED EMBODIMENTS
FIG. 1 illustrates a video tape cassette according to the
present invention, the cassette being indicated generally by
reference number 10. The cassette 10 includes a shell member
or base 12 and another shell member or cover 14, each made of
a plastic resin. The a~sembled base 12 and cover 14
accommodate a pair of tape reels 16 and 18 in a known manner.
As shown in FIGS~ 1 and 3, each of the tape r~els 16 and 18
includes a hub 20 and 22, respectively, for winding magnetic
recording tape 23 therearound. The tape reels 16 and 18 each
include a pair of flanges 21, fixed coaxially on the top and
lS bottom of the hubs 20 and 22, for protection of the upper and
lower edges of the tape 23.
At a central portion of the cassette cover 14 is a planar
area 24, at which spaced reel springs 26 and 28 are formed of
the same material as the cassette cover 14, in the same mold.
The springs 26, 28 are elongated springs molded integrally of
the cassette cover 14, in the preferred embodiment.
Preferably, as shown best in FIGS. 1 and 2, each spring
26, 28 includes a base 30 connected to the central planar area
24 of the cover 14. Each spring 26, 28 is planar and extends
at an angle of about 20-25 relative to the plane of the area
2~937
24, in a direction away from the dust door 13 at the front of
the cassette 10 and downwardly toward the cassette base 12.
This angle may be modified depending upon the resin chosen and
the thickness of the springs 26, 28~ Each spring 26, 28
includes two converging sides 32 and 34 terminating in a
straight free end 36. ~he sides 32, 3~ could, of course, be
parallel ins~ead. Each spring 26, 28 is spaced adjacent sides
32, 34 and end 36 from the cover 12, as shown by reference
numeral 38, which allows the spring 26, 28 to flex freely
relative to the cassette cover 14. This spacing also creates
openings ~2, 44 into which projections 72, 74 of the removable
dust door 50 extend, as di~cussed below.
As shown in FIG. 3, when the cover 14 and base 12 are
mated, the springs 26, 28 are abutted and pushed by the tape
reel hubs 20, 22 to flex upward toward the area 24 as shown
by arrow "A". As a result, a portion 40 of the spring 26, 28
presses against the top 42 of the hubs 20, 22 to bias the hubs
2~, 22 downwardly as indicated by arrow "B".
According to the present invention, if a defect is found
in, e.g. the base 12 after the base 12 and cover 14 are
assembled, the cassette 10 can merely be disassembled ancl the
cover 14, including the reel springs 26, 28, can be re-used:
the base 12 can be melted down and re-formed, if necessary.
A benefit of this reel spring invention is that there is
no need to stamp a spring from a ~lat sheet of stainless
9 3 ~
steel~ The reel spring 26, 28 is made from the same material
as the cassette cover 14. ~hus, the prior art steps for
manufacturin~ the stamped spring are non~existent since the
spring stamping, hole forming, a~se~bly, etc. steps of the
S prior art can be eliminated.
With the present invention, there is no need to modify
the mold for forming the cassette base 12, only the mold fo.
the cover 14 needs to be modified.
Further, the cost of producing a stamped leaf spring is
non-existent since no metal is used: less expensive plastic
can be u~ed to make the reel springs. Further, plastic
material previously occupying part of the cassette cover is
merely transformed into the springs 26, 28. Also, the
likelihood of the spring becoming dislodged during assembly
is eliminated. These ~eatures, of course, further lead to
reducing the overall cost of the cassette.
Moreover, i~ there is a need to re-cycle the cover (e.g.,
if a tape cassette return policy should be instituted in the
future to conserve energy and materials much the same as is
now done with plastic bottles), there is no need to separate
a metal spring from the plastic cover. This bene~it decreases
recycling costs, facilitates re-melting of the cassette cover
for re-use of the plastic, and generally makes re-cycling more
attractive.
-- 10 --
2 ~ 3 7
As shown particularly in FIGS. ~-9, the tape cassette 10
according to the present in~ention also includes a removable
dust door 50. A ront portion 52 of the dust door 50 includes
an elongated wall 54, a perpendicular wall 56, left and right
corners 58, 60, and lowPr retainers 59, 61. The wall 54
ser~es su~stantially to protect the tape 23 from debris,
contact, etc., when the dust door 50 is connected to the
cassette 10. The front wall 54 of the dust door 50 can also
receive advertising~ labeling, etc.
R rear portion 62 of the dust door 50 includes an
extension 64 having two arms 6~, 6B extending substantially
perpendicular from the wall 56 and being connected to a third
arm 70, which is parallel to the wall 56. The third arm 70
include.s a curved recess 71 which can receive the user's thumb
nail to facilitate removal of the dust door 50.
The dust door 50 also includes a palr of projections 72
and 74. Ths pro3ections 72, 74 are preferably formed
integrally of the dust door 50 during molding thereof. The
projections 72, 74, as can be seen in FIGS. 4-6 and 9, include
a planar base mem~er 76, and an elongated planar,
perpendicular member 78. The perpendicular member 78 includes
a hook member 80. Each of the members 76, 78, 80 is formed
at the intersections of the arms 66, 68 and 70.
The openings 42, 44 formed in the cassette cover 14
receive the projections 72, 74, respectively, when the dust
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2 ~ 3 7
door 50 is moved into the closed position on the tape cassette
10. In this way, debris, dust, etc. is prevented from
entering the openings 42, 44 when the cassette 10 is not in
use.
More particularly, FIG. 5 is a perspective view of the
dust door 50 according to the present invention as it is being
disengaged from or being connected to the cassette 10. In
re~ard to connection, the extension 64 of the dust door 50 is
moved at a slight upward angle toward the cassette 10. The
dust door corners 58, 60 are generally configured to be
received by the cassette recessed front cornexs 90, whose
shapes are generally dictated by the conventional dust door
shape. The retainers 5g, 61 are received by the front lower
edges of the cassette base 12. ~he extension 6~ is pushed
downwardly against the cassette cover 14 so that the
proiections 72, 74 enter the openings 42 t 44 and the hooks 80
snap under the outer edge 92 of the openings 42, 44.
The projections 72, 74 serve the purpose o~ abutting and
depressing the molded springs 26, 28. This helps to maintain
the resiliency of the plastic springs 26, 28 for the expected
useful life o~ the cassette 10. For example, the projections
7Z, 74 ensure that the springs 26, 28 are not under load
during storage or shipment (which may entail a hot
environment). A plastic spring could lose integrity with time
under load and heat conditions.
2~6193~
In regard to disengagement, the reverse steps are
followed. That is, the extension ~4 is lifted slightly upward
and slightly flexed by placing the thum~ nail in the curved
recess 71, the projections 7~, 74 pop out from under the edges
92 of the openings 42, 44 and the duæt door 50 is removed,
which exposes the tape 23 to the tape player/recorder.
It is noted that disengag~ment/connection can occur with
the tape cassette base 12 on bottom or top. ~n either
position, the cassette 10 can be held, e.g. in the left hand,
the dust door 50 can be held in the right hand, and the dust
door 50 can be pulled off for disengagement and pushed on for
engagement.
The closed position of the dust door 50 is characteristic
of when the tape cassette 10 is not being operated by the tape
player/recorder, e.g., during shipping, handling, storage,
etc. In this position, the dust door 50 keeps the tape free
from du~t, contact, etc. The cassette with the dust door
thereon cannot be mis~akenly inserted in the tape
player/recorder because the added thickness provided by the
dust door prevents its receipt by the tape player/recorder.
The user must remove the dust door 50 from the closed position
as described above before loading the cassette i~ the tape
player/recorder. The dust door 50 is then put aside until use
of the tape cassette 10 in the tape player/recorder is
completed.
2 ~ 3 7
With the first embodiment dsscribed above, a conventional
dust door is used. With this first embodiment, it is aiso
desirable to incorporate a separate memb~r which both closes
the openings 42, 44 and abuts the springs 26, ~8, just like
tha above-described extension 64 does. More particularly, as
shown in ~IG. 10, the tape cassette 10 can include a removable
member 100 which is substantially rectangular. A front
portion 102 includes a curved recess 104 which can receive the
user's thumb nail to facilitate removal.
The member 100 also includes a pair of identical
projections 106 and 108 (not shown). The projections 106, 108
are preferably formed integrally of the member 100 during
molding thereof and are the same as the projections 72, 74
described above, including hook members 110.
In regard to attaching the member 100, the memker 100 is
moved toward the cassette 10 and pushed downwardly against the
cassette cover 14 so that the projections 106, 108 enter the
openings 42, 44 and the hooks 110 snap under the outer edge
of the openings 42, 44. In this way, debris, dust, etc. is
prevented from entering the openings 42, 44 when the cassette
10 is n~t in use.
The projections 106, 108 also serve the purpose of
abutting and depressing the molded springs 26, 28. This again
helps to maintain the resiliency of the plastic springs 26,
28. That ls, the projections ?06, 108 ensure that the springs
- 14 -
20~937
.
26, 28 axe not under load during storage, shipment, etc.
The user must remove the member 100 from the closed
position described above before loading the cass~tte 10 in the
tape player/recorder. The mem~er 100 is then put aside until
use o~ the tape cassette 10 in the tape player~recorder is
completed.
Thus, the present invention adequately addresses a void
created by the flex allowance of the springs, so that during
shipment or storage, the hubs are held tight against the base,
but the spring is doing no work. This void is compensated for
by the removable dust door 50 or removable member 100
described above. In either case, the projections 72, 74 and
106, 108, respectively, abut the spring~ 26, 28, thereby
pushing the tape reels against the base, where they are locked
against rotation as described above, by other means. The
removable dust door 50 or member 100 also covers the openings
42, 44 for~ed around the springs 26, 28 to prevent debris from
entering the cassette 1~.
As can be seen from the above description, one embodiment
20 of the prssent invention combines the conventional, separate,
multi-pieced, spring biased dust door and dust door latch into
a single member. Further, this single member can be
efficiently manufactured as one piece using plastic molding,
and assembly is greatly facilitated compared with the
conventional counterparts. The down time on the assembly
~0~193~
stations characteristic of asse~bly problem~ with the
conventional counterparts i5 also eliminated.
This relatively simple design allows for automated
assem~ly of the re~ova~le dust door on the tape cassette
during manufacture. ~he design also allows the consumer to
easily remove the dust door, put the tape into a tape
player/recorder for use, remove the tape after use and re-
attach the dust door.
Also, there is no need to significantly change the
1~ standards set for ths cassette or the tape player/recorder
design or operation.
Further, since it is a common practice to mak~ the
cassette and load the tape therein, the present invention
allows the duæt door to be added a~ter the tape is loaded and
the cassett~ is assembled. This facilitates tape loading~
Moreover, overall cassette a~sembly is facilitated
because, particularly, spring loading of a dust door and dust
door latch is eliminated. Also, the prior practice of having
to capture the dust door between the cassette base and cover
during mating thereof is eliminated. Finally, operation is
more reliable because there are no moving parts to this dust
door/reel leaf sprin~ combination.
The foregoing is considered illustrative only of the
principles of the invention. Further, since numerous
modifications and changes will readily occur to those skilled
- 16 -
2 ~ 3 7
in the art, ik i5 not desired to limit the invention to the
exact construction and operation shown and described. For
example, the above-described tape cassette has been shown to
be of the type intended for use in video tape
players/recorders. However, the invention can be similarly
applied to tape cassettes for use in audio or other
playing/xecording apparatus. ~oreover, although the reel
spring is characterized as being formed on the cover, the
spring could be formed on the cass~tte base, if desired.
Finally, a plurality of different spring shapes, e.g., curved,
triangular, etc. are possible, as long as one portion biases
against a tape reel hub. Also, the spring could be a bowed
rectan~ular shape, connected at both ends to the cassette, and
could be oriented parallel to the axis of the cass~tte.
Accordingly, all suitable modifications and equivalents may
be resorted to that fall within the scope o~ the invention and
the appended claims.
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