Note: Descriptions are shown in the official language in which they were submitted.
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SE$F-LOC~ING HUB ASSEMBLY FOR A COMPACT AUDIO
TAPE CASSETTE AND METHOD FOR ASSEMBLY
SPECIFICATION
BACRGROUND OF THE INVENTION
This invention relates to a compact, audio, tape cassette
and, more particularly, to a self-locking hub assembly for such
a tape cassette which prevents despooling of the recording tape
when the tape cassette is not engaged with a tape player/
recorder.
A conventional, compact, audio, tape cassette contains two
hubs onto which the tape is wound for supply and take-up during
operation. These hubs are located between the tape cassette
cover and base and are contained radially by pairs of raised
annular rings formed on the inside surfaces of the cover and
base which engage recessed rings on the top and bottom surfaces
of each hub. When engaged with a tape player/recorder, a finned
spindle thereof enters the center of the hub and cooperates with
spokes formed on the center of the hub to permit a driven
clockwise or counterclockwise motion of the hubs.
Because of industry tolerances, the spindles of one
manufacturer's tape player/recorder can be as much as 1/32 inch
different in relative location (closer or further apart) than
those of another manufacturer. It is, therefore, necessary to
create a clearance between the recessed rings formed on the hubs
and the raised annular rings formed on the tape cassette cover
and base. This clearance, however, means that, when a tape
cassette is disengaged from the tape player/recorder, the hubs
San turn freely and "despool," i.e., allow tape to spill
throughout the inside of the tape cassette. Such despooling is
not desirable because tape damage and jam conditions can result.
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In order to prevent despooling, manufacturers of compact,
audio, tape cassettes, an example of which is shown in FIG. 1
herein and referred to generally by reference numeral 10,
currently use a separate, elongated clip 12 having perpendicular
hooks 14 and 16 at the ends thereof which are manually inserted
into the centers 18 and 20 of the tape reel hubs 22 and 24,
respectively. The clip 12 is relatively simple, inexpensive and
requires little work to apply after the tape cassette 10 is
assembled. As a result, such clips 12 have gained widespread
acceptance in the compact, audio, tape cassette industry.
Unfortunately, however, the consumer ultimately removes the clip
12 to use the tape cassette 10 and usually discards the clip 12,
which again results in despooling during subsequent handling.
In arts other than the compact, audio, tape cassette art,
efforts have been made to prevent despooling. For example, U.S.
Patent No. 3,066,880, issued to BAUER, describes a self-locking
hub assembly for a single reel tape cartridge which is shown in
FIGS. 2 and 3 herein. More particularly, an axially and
radially extending slot 30 is formed in the hub 32 to receive a
movable member 34 for releasably coupling the hub 32 to the
cartridge 36. The movable member 34 is pivotally mounted on a
pin 38 extending across the slot 30 for angular movement
relative to the plane of the hub 32. The movable member 34
includes a detente portion 40 which is normally urged by a
spring 42 upwards toward the cartridge portion 44 to be received
in any one of a plurality of radially extending slots 46 formed
in the inside wall of the cartridge portion 44. The movable
member 34 also has an actuator portion 48 which can extend
inwardly from the inside wall 50 of the hub 32. Upon engaging
the cartridge 36 with a tape player/recorder (not shown), the
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spindle 52 thereof causes the movable member 34 to rotate, which
moves the actuator portion 48 outwardly and releases the hub 34
from the cartridge 36 so that the tape (not shown) can be
supplied and taken up under the control of the spindle S2.
The self-locking hub assembly described in the '880 patent
provides suitable self-locking for a single reel tape cartridge,
but is not applicable to a double reel, compact, audio, tape
cassette. As evidence, although the teaching of the '880 patent
has been available for almost twenty-five years and compact,
audio, tape cassettes have been available at least for twenty
years (see U.S. Patent No. 3,394,899, issued to SCH~ENMAKERS),
no one has successfully incorporated the type of self-locking
hub assembly taught by the '880 patent into a compact, audio,
tape cassette--the reasons follow.
First, the pivoting nature of the self-locking hub assembly
of the '880 patent works only when the single reel tape
cartridge is inserted into the tape player/recorder in the one
direction shown in FIG. 3 herein. If an attempt is made to
insert the single reel tape cartridge 36 in the opposite
direction, the movable member 34 would immovably abut the
spindle 52 and prevent insertion of the cartridge 36 into the
tape player/recorder. Compact, audio, tape cassettes, on the
other hand, are intentionally reversible, i.e., are designed to
be inserted into the tape player/recorder from two distinct
directions, the top first or bottom first, to play both "sides"
or "tracks" of the tape. As a result, if the self-locking hub
assembly of the '880 patent was used in a compact, audio, tape
cassette, it might be capable of locking the hub when the
cassette was not engaged with the tape player/recorder; however,
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unlocking of the hub and operation of the tape cassette would be
impossible when inserted in a second direction.
Second, the self-locking hub described in the '880 patent
requires enough vertical space in the cartridge to incorporate
at least one opening 46, the movable member 34, the pivot pin 38
and the spring 42. In addition, the movable member 34 must have
enough room to pivot up and down in order to operate. In a
compact, audio, tape cassette space is very limited. For
example, a self-locking hub assembly would have to occupy only
about 155 to 165 thousandths of an inch. As a result, a
compact, audio, tape cassette could not incorporate the several
members or the pivoting, angular motion required by the self-
locking hub assembly of the '880 patent. Further, in light of
the limited ability to insert the device of the '880 patent in
only one direction, if one were to attempt to make the movable
member 34 pivot in opposite directions to allow insertion of the
cassette top first or bottom first, more components and more
space would be re~uired, which a compact, audio, tape cassette
could not accommodate.
Third, relatively complicated assembly of the pivoting
device of the self-locking hub of the '880 patent in a compact,
audio, tape cassette is prohibited by the mere nature of
compact, audio, tape cassette manufacturing, wherein speedy,
simple and low cost, mass production are critical.
In light of the above, a more efficient and easier to
assemble self-locking hub assembly for a compact, audio, tape
cassette is desired, which prevents the hubs from rotating
whenever the cassette is not engaged with a tape player/
recorder, but allows easy release of the hubs, when the cassette
is inserted in either direction into a tape player/recorder. A
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faster and easier method for assembling a self-locking
hub assembly is also desired.
SUMMARY OF THE INVENTION
Accordingly, it is an object of an aspect of the
present invention to provide a self-locking hub assembly
for a compact, audio, tape cassette capable of cost
efficient manufacture and assembly, and reliable
operation.
It is an object of an aspect of the present
invention to provide a self-locking hub assembly for a
compact, audio, tape cassette capable of operational
movement only parallel to the plane of the hub to
minimize space requirements and allow insertion of the
cassette into the tape player/recorder in more than one
direction.
It is an object of an aspect of the present
invention to provide a self-locking hub assembly for a
compact, audio, tape cassette capable of easily locking
the hubs against rotation when the tape cassette is
disengaged from a tape player/recorder and easily
unlocking the hubs when inserted into the tape
player/recorder in either of two directions.
It is an object of an aspect of the present
invention to provide a self-locking hub assembly for a
compact, audio, tape cassette which efficiently fits
fully within the interior of the tape cassette without
undesirably interfering with the normal operation
thereof.
It is an object of an aspect of the present
invention to provide a compact, audio, tape cassette
with a self-locking hub assembly capable of automatic
operation unassisted by the user of the tape cassette.
It is an object of an aspect of the present
invention to provide a method of assembling a self-
locking hub assembly for a compact, audio, tape cassette
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characterized by greater speed and accuracy, facilitatedautomation and less cost than the prior art methods.
To achieve the foregoing and other objects of the
present invention and in accordance with the purposes of
the invention, there is provided an internal, self-
locking hub assembly for a compact, audio, tape
cassette, including a locking member with two movable
portions and spring means. The tape cassette includes
receiving means formed in a raised annular ring thereof.
When the tape cassette is disengaged from a tape
player/recorder, the spring means normally urges the two
movable portions radially inward parallel to the plane
of the hub, whereby the two movable portions engage the
receiving means, locking the hub and the tape against
rotation. On the other hand, when the tape cassette is
engaged with a tape player/recorder from either of two
directions, the spindle of the tape player/recorder
enters the center of the hub, abuts and pushes the two
movable portions against the force of the spring means,
thereby removing the two movable portions from the
receiving means and permitting the normal rotation of
the hub.
The related method includes the steps of: forming
the locking member to include two movable portions, a
spring means and a locating means; picking up the
locking member; forming a hub to include mounting means
corresponding to the locating means; advancing the
locking member to the hub; inserting the locking member
into the hub such that the locating means is received by
the mounting means; mounting the hub into a cassette
base; forming a cassette cover with receiving means; and
positioning the cassette cover on the base, such that
the receiving means receives the at least one movable
portion.
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Various aspects of this invention are as follows:
A self-locking hub assembly for use in a tape cassette
having at least one hub to be rotated by a spindle of a tape
player~recorder, the tape cassette also including opposing,
substantially planar cover and base, each having a raised
annular ring for locating the at lease one substantially planar
hub of the tape cassette, comprising:
(a) a unitary, locking member positioned on a surface
of the hub with first and second portions movable in a plane
parallel to the plane of the hub;
~b) receiving means formed on the raised annular
ring; and
(c) sprir.g means associated with the locking member
to normally bias the first and second movable portions radially
inward parallel to the plane of the hub, thereby engaging the
first and second movable portions with the receiving means
formed on the raised annular ring and preventing rotation of the
hub;
wherein the spring means comprises first and second
spring arms extending from a central portion of the locking
member to the first and second movable portions, respectively
wherein each movable portion is formed at the end of
each spring arm opposite the end extending from the central
portion of the locking member, and
wherein, when the tape cassette is inserted in either
direction into the tape player/recorder, the spindle of the tape
player/recorder enters the hub, abuts and moves each movable
portion radially outward parallel to the plane of the hub,
thereby removing each movable portion from engagement with the
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receiving means and allowing the hub to be rotated by the
spindle.
A tape cassette for use in a tape player/recorder,
comprising:
(a) a substantially planar cover;
(b) a substantially planar base, the base fitting on
the cover with the substantially planar portions parallel to
define an enclosed space;
(c) at least one raised annular ring formed on the
cassette including receiving means formed therein;
(d) at least one substantially planar tape reel hub
located in the enclosed space by the at least one raised annular
ring, the hub including a central opening for receiving a
spindle of the tape player/recorder;
(e) a unitary locking member positioned on a surface
of the hub with first and second portions movable in a plane
parallel to the plane of the hub; and
(f) spring means associated with the locking member
for normally biasing the first and second movable portions
radially inward, thereby engaging the first and second movable
portions with the receiving means and preventing rotation of the
hub,
wherein the spring means includes first and second
spring arms extending from a central portion of the loc~ing
member, and
wherein the first and second movable portions are
formed at the end of each spring arm, respectively, opposite the
end extending from the central portion of the locking member,
and
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wherein, when the tape cassette is inserted in either
direction into the tape player/recorder, the spindle enters the
hub central opening, abuts and moves the first and second
movable portions radially outward parallel to the plane of the
hub, thereby removing the first and second movable portions from
the receiving means and allowing the hub to be rotated by the
spindle.
A method for assembling a self-locking hub assembly
for a tape cassette, comprising the steps of:
(a) forming a unitary locking member having first and
second movable portions, spring means and locating means,
wherein the spring means includes first and second
spring arms extending from a central portion of the locking
member, and
wherein each movable portion is formed at the end of
each spring arm, respectively, opposite the end extending from
the central portion of the locking member;
(b) forming a hub with a central opening and mounting
means on an exterior surface thereof corresponding to the
locating means;
(c) picking up the locking member;
(d) advancing the locking member to a tape reel hub;
(e) locating the locking member on the exterior
surface of the tape reel hub such that the locating means is
fixedly received by the mounting means and the first and second
movable portions extend into the central opening in the hub;
(f) mounting the tape reel hub into a cassette base;
(g) forming the cassette cover to include receiving
means; and
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1~0~ ,3
(h) positioning the cassette cover on the base such
that the receiving means receives the at least one movable
portion.
~RIEF DESCRIPTION OF T~E DRAWIN~S
The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate embodiments
of the invention and, together with the description, serve to
explain the principles of the invention.
FIG. 1 is a top, planar view of a conventional compact,
audio, tape cassette, illustrating particularly the use of an
elongated clip having end hooks inserted into the hubs to
prevent despooling.
FIG. 2 is a si~e, cross-sectional view of a conventional
self-locking hub assembly for a single reel tape cartridge,
illustrating particularly the cartridge disengaged from a tape
player/recorder~
FIG. 3 is a side, cross-sectional view of the self-locking
hub assembly shown in FIG. 2, illustrating particularly the
single reel tape cartridge engaged with a tape player/recorder.
FIG. 4 is a top, plan view of the compact, audio, tape
cassette according to the present invention, illustrating
particularly the first embodiment of the self-locking hub
assembly while the tape cassette is disengaged from a tape
player/recorder.
FIG. 5 is a top, plan view of one of the tape reels shown
in FIG. 4.
FIG. 6 is a top, plan view of one of the locking members
shown in FIG. 4.
FIG. 7 is a side, cross-sectional view of the locking
member shown in FIG. 6 taken along line 7-7.
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FIG. 8 is a front, cross-sectional view of the self-locking
hub assembly shown in FIG. 4 taken along line 8-8.
DETAIT.~n DESCRIPTION OF TH~ PR~E~RRED EMBODIMENTS
The preferred embodiments of the present invention will now
be described with reference to FIGS. 4-8, wherein like reference
numerals indicate like parts.
A tape cassette 62 includes a cover 64 and a base 66, each
of which are preferably made of a clear, hard plastic such as
styrene. Positioned within the cover 64 and base 66 are a first
tape reel hub 68 and a second tape reel hub 70 which supply and
take up the tape 72 in the tape cassette 62. Each tape reel hub
68 and 70 is preferably made of a dark-colored plastic such as
acetal. Elevated areas 74 and 76 can be formed in the cover 64
and the base 66 of the tape cassette 62, respectively, for
receiving a tape guide 78, such as described in co-assigned U.S.
Patent No. 4,506,846, now U.S. Reissue Patent No. 32,447.
Although only a single hub is shown in FIGS. 5 and 8, it is
to be understood that the present invention contemplates a
similar structure for each of the two hubs in a compact, audio,
tape cassette such as shown in FIG. 4.
Associated with each first tape reel hub 68 is a self-
locking hub assembly 69. Associated with each second tape reel
hub 70 is also a self-locking hub assembly 71 identical to the
assembly 69. As a result, only the self-locking hub assembly 69
will be described hereafter in detail.
The self-locking hub assembly 69 includes a locking member
80, at least one portion of which is movable relative t the hub
68. More particularly, the locking member 80 includes spring
means 81 in the form of two flat, angled spring arms 82 and 84
extending from a central, flat portion 86 of the locking member
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80. Main portions 83 and 85 of the spring arms 82 and 84 are
substantially parallel to each other. Each spring arm 82 and 84
preferably terminates in an abutting portion 92 and 94,
extending perpendicular and coplanar to the main portions 83,
85, respectively. Connected to each of the abutting portions
92, 94 is an upwardly projecting engaging portion 93 and 95,
respectively. Each spring arm 82, 84 normally biases the
respective and movable abutting portions 92, 94 and the
operatively connected engaging portions 93, 95 radially inward
as shown by arrow "A" in FIG. 4 relative to the center line 90
of the tape reel hub 68. Optionally, each spring arm 82 and 84
may also include an upright, reinforcing member 87, 89, each of
which is intended to add rigidity to the spring arms 82 and 84
and to prevent upward bowing thereof.
In addition, the central portion 86 of the locking member
80 includes on the top surface 97 thereof a reinforcing member
96 and on the bottom surface 99 thereof locating means 98, such
as a pair of parallel, rectangular ribs 100 and 102.
The hub 68 includes mounting means 104, such as a pair of
parallel rectangular openings 106 and 108 (see FIG. 5)
corresponding to the pair of rectangular ribs 100 and 102 of
locating means 98. The hub 68 also includes an inner annular
wall 110 having two opposing openings 112, 114 formed therein
for receiving the abutting portions 92 and 94, respectively.
The hub 68 also has an outer annular wall 116.
Raised annular rings 118 formed on the inside surface of
the cover 64 of the tape cassette 62 include receiving means 120
therein, such as a plurality of radially spaced receptacles 122.
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operation o~ the present invention will now be described.
Normally, the locking member 80 is kept in the "locked" position
shown in FIG. 4. That is, the spring arms 82, 84 bias the
abutting portions 92, 94 and engaging portions 93, 95 inwardly
such that the engaging portions 93, 95 are received by two
oppositely disposed receptacles 122 in the raised annular ring
118 of the cover 64. As a result, the hub 68 is prevented from
rotating and no "despooling" of the tape occurs. On the other
hand, upon insertio~ of the tape cassette 62 into a tape
player/recorder as shown in FIG. 8, the finned spindle 124 of
the tape player/recorder abuts and pushes on the movable
abutting portions 92, 94, which causes the operatively connected
and engaging portions 93, 95 to also move radially outward
against the biasing force of the spring arms 82, 84. As the
engaging portions 93, 95 move outwardly, they leave the
receptacles 122, thereby releasing the hub 68 from the "locked"
position and creating the "unlocked" position. In the unlocked
position, the hubs 68, 70 are free to rotate on the raised
annular rings 118 and transport tape while being driven by the
spindle 124 of the tape player/recorder.
FIGS. 4-8 also illustrate the method of assembly according
to the present invention, which comprises the following steps.
First, the locking member 80 shown in FIGS. 6 and 7 is formed to
include: the two movable portions, i.e. the engaging portions
93, 95 with the abutting portions 92, 94; spring means 81; and
locating means 98 as described above. Second, the locking
member 80 is picked up by an automated apparatus (not shown),
such as a robot arm. Third, the locking member 80 is advanced
to a tape reel hub 68 formed to include mounting means 104
correspo~ding to the locating means 98, such as shown in FIG. 5.
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Fourth, the locking member 80 is inserted into the hub 68 such
that the locating means 98 is fixedly received by the mounting
means 104. Fifth, the hub 68 is mounted in a cassette base 66
as shown in FIGS. 4 and 8. Sixth, a cassette cover 64 is formed
to include the receiving means 120. Seventh, and finally, the
cassette cover 64 is positioned on the base 66 such that the
receiving means 120 receives the engaging portions 93, 95, as
shown again in FIGS. 4 and 8.
The foregoing is considered illustrative only of the
principles of the invention. Further, since numerous
modifications and change will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described. Accordingly,
all suitable modifications and equivalents may be resorted to,
falling within the scope of the invention and the appended
claims.
