Note: Descriptions are shown in the official language in which they were submitted.
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This application is a division of appli-
cation Serial No. 450,230, filed March 22, 1984.
This invention relates to an apparatus
using a disc-shaped record bearing medium/ such as a
disc player.
In the recording and/or reproducing
apparatus using a rotation type record bearing medium
of disc shape, for example, rotation type flexible
magnetic disc, rotation of the magnetic disc is
performed after an engaging hole of the center core
in the central portion of the magnetic disc has been
engaged with a spindle which is driven to rotate by
an electric motor. This type of apparatus has a
problem that when the engagement of the center core
with the spindle is loose, it becomes impossible to
make sure the magnetic disc does normal rotative
motion during recording or reproduction, and
conversely when the aforesaid engagement is
tightened, the magnetic disc becomes difficult to
load on the spindle.
Therefore, a method has been proposed that
a magnetizable member is applied to the center core,
while a magnet piece is mounted on the flanged
portion of the spindle. However, even in such
magnetic coupling method, it is difficult to assure
that when the center core is put on the spindle, it
takes a certain position relative to a reference
surface, for example, the flange surface of the
spindle. Therefore, it is difficult to hold the
magnetic disc in a predetermined setting surface for
maintenance of
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~~ predetermined aligning state between it and a recording
and/or reproducing head. Also in a still picture recording
and/or reproducing apparatus having the rigorous requirement
for accuracy of alignment~ the force necessary to load the
center core on the spindle amounts up to hundreds of grams.
As the magnet piece is of large size, therefore, the size
and weight of the apparatus is hindered from being reduced.
On the other hand, there has been proposed an
apparatus provided with a mechanism for pressing a portion
of the magnetic disc against the spindle as in the floppy
disc device. Since, in this type of apparatus, that portion
of the apparatus which drives rotation of the disc operates
under the condition that the aforesaid mechanism applies
a pressure on the spindle through the disc, its load becomes
large, causing the speed of rotation to vary at random.
Summary of the Invention: -
It is, therefore, a main object of the presentinvention to eliminate the above-described drawbacks of
the conventional apparatus and to provide an apparatus
using a disc-shaped record bearing medium which apparatus
is capable of always well assuring that when to load the
disc-shaped record bearing medium, the record bearing medium
is set on a rotative drive member accurately and reliably.
Another object of the present invention is to
provide an apparatus using a disc-shaped record bearing
~edium which apparatus operates without having to apply
a large load on the aforesaid rotative drive member while
still permitting the aforesaid object to be accomplished,
ereby giving an advantage that -the bulk and size of the
rotative drive member can be reduced.
Still another object of the present invention is
to provide an apparatus using a disc-shaped record bearing
medium in which when the record bearing medium is loaded
on a rotative drive member by operating a pressing member
for pressing a portion of the recoxd bearing medium against
a receiving surface of the aforesaid rotative drive member,
a reliable and smooth loading operation can be realized
by a pressing force which is always almost constant despite
there are configuration errors and fitting position errors
of the pressing member, or members constituting an operating
mechanism for the pressing member.
Under the first one of the above-mentioned objects,
according to preferred embodiments embodying the aspect of
the present invention, an apparatus arranged to use a
disc-shaped record bearing medium having an engaging portion,
comprises rotating means engageable with the medium at its
engaging portion and having a surface for receiving the
engaging portion of the medium; holder means movable
between a first position for receiving the medium and a
second position for positioning the received medium at
a predetermined position relative to the rotating means;
pressing means for pressing the engaging portion of the
medium against the receiving surface of the rotating
means; and control means for operating the pressing means
when the holder means is moved from its first to its
second position.
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Especially, under the second one of the
above-mentioned objects, according to preferred
embodiments embodylng the aspect of the present
invention, the control means is arranged to operate
the pressing means and thereafter disable the
pressing means during the movement of the holder
means from its first to its second position.
Under the third one of the above-mentioned
objects according to first, second and third
embodiments embodying the aspect of the present
invention, the control means is arranged to disable
the pressing means when the holder means reached a
predetermined position nearly before its second
position. In these embodiments, the pressing means
preferably has an elasticity in at least a part
thereof. On the other hand, according to fourth and
fifth embodiments embodying the aspect of the present
invention, the control means is arranged to disable
the pressing means when the resistant force exerted
on the pressing means reached a predetermined value.
In accordance with a further embodiment of
the invention there is provided an apparatus to
handle a flexible disc having a center core which is
attached at a central portion of the disc and is
provided with an engaging hole, said apparatus
comprising:
(A) a spindle engageable with said engaging
hole of the center core of the disc, said spindle
having a flange portion for receiving thereon said
center core;
(B) a pressing member for pressing said center
core of the disc against said flange portion of the
spindle, said pressing member having at least a pair
of pressing portions each having projections, said
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pressing portions being arranged to act on respective
almost diametrically opposite portions on an annular
surface of the center core; and
(C) an operation mechanism for causing said
pressing member to press the center core of the disc
through said pressing portions.
In accordance with a still further
embodiment of the invention there is provided an
apparatus arranged to handle a disc having an
engaging portion, said apparatus comprising:
(A) rotating means for rotating said disc, said
rotating means having an engageable portion engage-
able with said engaging portion of the disc and a
receiving surface ~or receiving thereon the engaging
portion of the disc;
(B) loading means for loading the disc at a
predetermined position relative to said rotating
means;
(C) pressing means for pressing said engaging
portion of the disc against said receiving surface of
the rotating means; and
(D) control means for operating said pressing
means to press said engaging portion and to
subsequently release from said portion while said
loading means is loading said disc.
In this invention, the term "record bearing
medium" refers to a rotatable record bearing medium
of disc-shape in the magnetic, optical, or
electrostatic capacity type recording and/or
reproducing system, and the term "rotating means" for
the record bearing medium refers to a rotative drive
member such as a spindle connected to, or driven by,
a drive source such as an electric motor.
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Other objects and features of the present
invention will become apparent from the following
description of the explanation by reference to the
accompanying drawings.
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~'rief Description of the Drawings:
In the following, this invention will be des-
cribed in conr.ection with preferred embodiments thereof
by reference to the accompanying drawings in which:
Fig. l is a perspective view of a prior known
magnetic disc cassette.
Fig. 2 is a sectional view of the main parts of
a conventional apparatus.
Fig. 3 is a sectional view of a first embodiment
of the invention.
Figs. 4 and 5 illustrate a manner in which the
apparatus of Fig. 3 operates between a position where the
cassette holder is pushed downward and another position
where it is lifted upward.
Figs. 6 and 7 are sectional views of the main
parts of second and third embodiments of the invention
respectively.
Fig. 8 is a fragmentary elevational view in
enlarged scale of a part of the apparatus of Fig. 7.
Fig. 9 is a sectional view of a fourth embodiment
of the invention.
Figs. lO and ll illustrate a manner in which the
àpparatus of Fig. 9 operates between a position where the
cassette holder is pushed downward and another position
where it is lifted upward.
Figs. 12, 13 and 14 illustrate the main parts of
a fifth embodiment of the invention, with Fig. 12 in a
sectional view in an operative position where a pressing
member is pressing the center core of the magnetic disc,
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-9ig. 13 in a sectional view in another operative position
where the pressing member is escaped or disabled by a
reaction or a resistant force from the center core,
and Fig. 14 in a sectional view in anotAer operative
position where the pressing member has returned to the
initial position.
Detailed Description of the Preferred Embodiments:
The conventional apparatus using the disc-shaped
record bearing medium (Fig. l and Fig. 2):
Prior to the description of a conventional
apparatus-using the disc-shaped record bearing medium,
a prior known magnetic disc cassette is explained with
reference to Fig. l. In the drawings, l is a flexible
magnetic disc as an example of a disc-shaped record
bearing medium; 2 is a cassette containing the magnetic
disc l and has a housing in the box form as illustrated
in the drawing; 3 is a center core fixedly attached to a
central portion of the magnetic disc l and having an engaging
hole 3a; 2a and 2b are apertures provided in portions of
the cassette 2 in correspondence to the center core 3;
2c is a window provided in a portion of the cassette 2 so
as to allow insertion of a magnetic head to be described
later; and 4 is a magnetizable plate fixedly attached to
the lower surface of the center core 3. The magnetic disc l
while being contained in the cassette 2 is loaded into a
recording and/or reproducing apparatus by, for example,
means to be described later, and then recording or re-
producing is carried out in a manner known in the art.
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" Fig. 2 illustrates the main parts of the con~
ventional apparatus using the disc-shaped record bearing
medium in which the loaded cassette 2 is indicated by two-
dotted and dashed lines. Members denoted by the same
reference characters as those in Fig. 1 have similar con-
structions and functions to those of the members of
Fig. 1. As to other members, 6 is an internal chassis of
the recording and/or reproducing apparatus; 7 is an electric
motor for rotation of the disc and is fixedly mounted to the
chassis; 8 is a spindle as an example of a rotating means
fixedly mounted on an output shaft 7a of the disc rotation
motor 7. The aforesaid center core 3 is adapted to be mounted
on the spindle 8 at the engaging hole 3a thereof. 10 is
a magnetic head as an example of the recording and/or re-
producing head; 11 is a head carriage. 9 is a magnet fixedly
mounted on the upper surface of a flanged portion 8a of the
spindle 8. According to the prior art, it is by this
magnet 9 and the magnetizable plate 4 of the center core 3
that the center core 3 and the spindle 8 are brought into
coupling with each other magnetically. By this method,
however, as has been described above, it is difficult to
assure that the magnetic disc 1 is maintained in a pre-
determined mounting surface defined by the flanged portion
8a of the spindle 8.
In another prior art example where use is made
of a mechanism acting on the upper surface of the center
core 3 and pressing it against the spindle 8, as has been
mentioned above, the disc rotating motor 7 is caused to
operate with this mechanism also as a load. The total load
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~f the motor 7 is, therefore, increased, which becomes a
cause of uneven speeds of rotation.
A first embodiment of the present invention (Figs. 3 to 5):
In Figs. 3 to 5, the same reference characters
have been employed to denote the parts having fundamentally
similar constructions and functions to those of the parts
in Figs. 1 and 2, and their explanation is omitted. 21 is
a cassette holder. The magnetic disc cassette 2 after
having inserted into and seated in the holder 21 is
loaded onto a rotative drive portion. For this purpose,
the holder 21 is movable between a position shown in Fig. 3,
~r a first position for receiving the cassette 2, and a
position downwardly slightly beyond the position of Fig. 4,
or-a second position where the center core 3 of the magnetic
disc 1 contained in the received cassette 2 is mounted on
the spindle 8. It is to be noted here that though not
shown the holder 21 is provided in its interior with means
having a leaf spring and abutments for determining a right
position of the received cassette 2 in the interior of the
holder 21. 22 is a position determining portion for the
cassette 2, and a plurality of this portion are provided
~n the chassis 6. These portions may be constructed either
as a unit with, or in separation from, the chassis 6. 23
is a pressing arm as an example of pressing means in this
invention. The pressing arm 23 is pivotally mounted at a
shaft 24. The shaft 24 is fixedly mounted on an armed
portion 34 of another chassis 25 formed either as a unit
with, or in separation from, the chassis 6. 23a is a
~ressing portion at the free end of the pressiny arm 23.
As illustrated in Fig. 4, when the pressing arm 23 turns
in a clockwise direction, this pressing portion 23a pushes
the center core 3 with its engaging hole 3a in engagement
with the spindle 8. For this purpose, use may be made
either of two pressing portions 23a of fork shape
arranged to act on respective diametrically opposite points
on an annular upper surface of the center core 3 above
and below the paper of Fig. 4 respectively, or of a top
plate on the upper surface of the center core 3 so that
the center core 3 is pushed at the whole upper surface
thereof by the pressing portion 23a. 23b is a projected
portion extending from the pressing arm 23 upwardly of
the paper in Fig. 3 and having abutment portions 23b' and 23b".
26 is a lever rotatable about a shaft 27 planted
on the arm 23. 28 is a torsion spring turned around the
shaft 27, one end of which is laid on the lever 26 and the
other of which is laid on the abutment portion 23b' of
the projected portion 23b of the pressing arm 23. Therefore,
the lever 26 is urged by the torsion spring 28 to turn
about the shaft 27 in a clockwise direction until its tail
26a abuts on the abutment portion 23b" of the projected
portion 23b of the pressing arm 23. 29 is a lever with
its tail end portion pivotally mounted on a shaft 30
planted on an armed portion 35 of the chassis 25. The
position of the lever 29 is so determined that when it
turns in a clockwise direction, its free end portion 29a
abuts on a free end portion 26b of the lever 26. For
note, the free end portion 29a of the lever 29 is formed to
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~n other suitable cam shape. 31 is a pin planted on the
lever 29 and engaging in a slotted portion 21b provided in
an extension 21a of the cassette holder 21. 32 is a
spring urging the pressing arm 23 to turn in a counter-
clockwise direction to an initial position. 33 is a
limiting portion for limiting the counterclockwise re-
turning movement of the pressing arm 23. The limiting
portion 33 is provided on the chassis 25.
In the above-described construction, when in
the condition of Fig. 3, the magnetic disc cassette 2
is inserted into the cassette holder 21. After the
magnetic disc cassette 2 has been seated in a right position
within the interior of the holder 21, then the holder 21
is moved downward or in a direction indicated by arrow A
in Fig. 3. In order to do this, the holder 21 may be
operatively connected-to the chassis or its cover portion
by, for example, a hinge provided on the back-side of the
paper of Fig. 3 so that the holder 21 is moved downward
manually or by a mechanism known to those skilled in the
art. As the holder 21 moves downward, the pin 31 en-
gaging in the slot 21b of the extension 21a moves in a
direction of arrow A, thereby the lever 29 is turned
in a direction of arrow D in Fig. 4. Therefore, the free
end portion 29a of the lever 29 comes to contact with the
free end portion 26b of the lever 26 and then pushes the
lever 26 in a direction of arrow E. Since, at this time,
the lever 26 is hindered from pivotal movement by its
tail portion 26a resting in the abutment 23b" of the
projècted portion 23b of the pressing arm 23, the pressing
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arm 23 reacts to turn about the shaft 24 in the clock~ise
~irection, thereby its free end or pressing portion 23a
enters the interior of the holder 21 through an apertured
portion 21c thereof and pushes the center core 3 at the
upper surface thereof along the spindle 8 against a frictional
force exerted therebetween. Here, in the position shown
in Fig. 4, the holder 21 does not yet reach its downmost
possible position. Therefore, between the lower surface
of the center core 3 and the upper surface or position
determining surface of the flanged portion 8a of the spindle 8
lies a gap Q, as illustrated in Fig. 4. Upon further down-
ward movement of the holder 21, the lever 29 is further
turned in the direction of arrow D. Therefore, the pressing
arm 23 also further turns in the clockwise dir:ection, so
that its pressing portion 23 further pushes the center core 3
to eliminate the aforesaid gap Q. Thus, the magnetic disc l
is positioned right at a predetermined location defined
by the f7anged portion 8a of the spindle 8.
Because the center core 3 is usually made of
plastics, the diameter of its engaging hole 3a largely
varies from item to item in a sense of fitting on the
spindle 8. According to the above-described construction
of the apparatus, as the diameter of the engaging hole 3a
of the center core 3 is designed to be rather small, the
range of variation of the diameter has no longer any
effect on the accuracy of positioning control. Therefore,
the present invention is suited to the mass production.
This advantage can be expected in other embodiments of
the invention to be described later also.
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- As the cassette holder 21 further moves downward
ln the direction A, the lever 29 continues to turn in the
direction D, finally disengaging its free end portion 29a
from the free end portion 26b of the lever 26. And, at this
time, a bias force of counterclockwise direction by the
spring 32 acts on the pressing arm 23. Therefore, when the
engagement of the lever 29 and the lever 26 is released,
the pressing arm 23 immediately turns in the counter-
clockwise direction, returning to the initial position
defined by the limiting portion 33.
By the way, because the pressing arm 23, lever 26,
lever 29 and cassette holder 21 may have form tolerances
and the pivot shafts 24, 27 and 30 and the pin 31 also
may have location tolerances, there will be some possibility
that even when the pushing of the center core 3 along the
spindle 8 by the pressing portion 23a of the pressing arm 23
has finished, the engagement of the free end portion 29a
of the lever 29 and the free end portion 26b of the lever 26
is not released, thereby a so-called "wrenching" is caused
to occur therebetween. This will lead to interfere with
the smooth loading operation. On this account, the pressing
arm 23 is made elastic in at least a portion indicated by
23c in Fig. 4 so that when the aforesaid situation is
encountered, this portion indicated at 23c is bent as
illustrated in the drawing, permitting the free end portion
29a of the lever 29 to smoothly run over the free end portion
26b of the lever 26. Thus, it is made possible to assure that
the engagement of both the levers is released as it moves
in the direction D. rhe use of such elasticity in one
`~rtion (23c) of the pressing arm 23 has another advantage
that as the center core 3 is pushed, even when the pressing
arm 23 is overpowered, the excessive stroke is absorbed
by this elastic portion 23c to prevent the center core 3,
the flanged portion 8a of the spindle 8 and the pressing
arm 23, or the operating mechanism (26-31) therefor from
being damaged. This point is valid even in second and
third embodiments of the invention to be described later.
By the counterclockwise movement of the pressing
arm 23, its pressing portion 23a leaves from the center
core 3 so that when the magnetic disc 1 is driven to rotate,
its drive source or disc rotating motor 7 is freed from
the surplus load. Also the center core 3 and the spindle 8
are tightly coupled with each other by friction. Under
such conditions, the magnetic disc 1 rotates while the
magnetic head 10 performs recording or reproducing in a
manner known in the art.
When to take out the cassette 2 from the holder 21,
the holder 21 is lifted in a direction indicated by arrow B
by the reversed operation to the aforesaid operation of
moving downward to the direction A. This step of operation
is illustrated in Fig. 5. Such upward movement causes the
pin 31 also to be moved upward which in turn causes the
lever 29 to turn about the shaft 30 in a direction F.
Though the free end portion 29a of the lever 29 contacts
again with the free end portion 26b of the lever 26, it
is in this case that the free end portion 29a of the
lever 29 comes from the below to abut on the free end
portion 26b of the lever 26, and therefore that the
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lever 26 is turned about the shaft 27 in a direction ~
until the engagement of the free end portion 26b of the
lever 26 and the free end portion 29a of the lever 29 is
released. Then, the lever 26 is returned by the spring 28
to the initial position shown in Fig. 3. Further, when the
holder 21 is raised to the predetermined position (aforesaid
first position), each member returns to the position of
Fig. 3. In this position, the cassette 2 becomes possible
to be taken out from the interior of the holder 21.
A second embodiment of the present invention (Fig. 6):
In Fig. 6, though the disc rotating motor and
spindle are not shown, these members are similarly constructed
and arranged to the aforesaid first embodiment. In Fig. 6,
41 is a support member fixedly mounted to a left hand
portion of the cassette holder 21 and movable as a unit
therewith; 42 is a lever pivotally supported by a shaft 44
on the support member 41; 43 is a spring trained between
the support member 41 and the lever 42. The lever 42 is
urged by the spring 43 to turn about the shaft 44 planted
on the support member 41 in a clockwise direction as viewed
in the drawing. 21d is an extension formed in a portion
of the holder 21 to receive a tail end portion 42a of the
lever 42 against the spring 43. 42b is a free end portion
of the lever 42 abutting on a cam portion 23e provided in
the tail end portion 23d of the pressing arm 23.
With such construction, when the cassette holder 21
moves downward or in the direction A in the drawing
similarly to the aforesaid first embodiment, the lever 42
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~lso moves downward, while its free end portion 42b
pushing the tail end portion 23d of the pressing arm 23
at its camming surface 23e. Therefore, the pressing arm 23
turns in a clockwise direction as viewed in the drawing,
while its free end or pressing portion 23a entering past
the apertured portion 21c of the holder 21 into the
interior of the holder 21 and to push the center core 3
in fitting engagement on the spindle 8. As the holder 21
further moves downward, when the free end portion 42b of
the lever 42 overruns the cam portion 23e the pressing
arm 23 finishes the pushing and is turned by the spring 32
in the counterclockwise direction to the initial position,
thereby its free end pressing portion 23a moves away from
the center core 3.
On the other hand, when the holder 21 is raised
from its downmost position to the direction B in the drawing,
the free end portion 42b of the lever 42 comes from the
reversed direction to that described above to abut on the
cam portion 23e in the tail end portion 23d of the pressing
arm 23. Since the spring 43 is weak, it is at this time
that while the pressing arm 23 is left stationary,
the lever 42 turns in a counterclockwise direction as
viewed in the drawing. Then when the holder 21 rises to
the predetermined position, the lever 42 returns to the
initial position shown in Fig. 6. By one series of these
operations, similarly to the above-described first embodiment,
it is made possible to actuate the pressing arm 23 in response
to downward movement of the holder 21 to thereby set the
center core 3 on the spindle 8 and thereafter to remove the
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``-essing portion 23a of the pressing arm 23 from the de-
pression on the center core 3.
A third embodiment of the present invention (Fiqs. 7 and 8):
In Figs. 7 and 8, 21e is an extension provided
on the left hand side portion of the cassette holder 21;
51 is a slide lever; 52 is a spring trained between the
extension 21e and a hole 51a of the slide lever 51 so that
the slide lever 51 is urged toward the back of the paper.
53 is a pin fixedly mounted on the left hand side portion
of the holder 21 to guide sliding movement of the slide
lever 51 in a direction perpendicular to the paper. 54 is
a pin planted on the slide lever 51 and extending backward
from the paper into a groove 55 provided in the surface of
a tail end portion 23f of the pressing arm 23. The groove
55 is, as illustrated in greater detail in Fig. 8, formed
to letter "D" shape as viewed from the front of the paper
with its portions indicated by "m", "n" and "p" having a constant
depth, another portion indicated by "q" having gradually
shallower depths as the distance from the below to the
above increases, and the top end indicated at "r" being
followed by a sudden drop, so that as the holder 21 moves
first downward and then upward, the pin 54 is caused to
circulate in the closed groove 55, always first to a direction K
followed by a direction L.
With such construction, similarly to the above,
when the holder 21 mo~es downward or in the direction A in
the Fig. 7, the pin 54 moves along portion "m" of the
groove 55 in the direction K so that the pressing arm 23
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urns about the shaft 24 in a clockwise direction as viewed
in the drawings. By the clockwise movement of the pressing
arm 23, its free end or pressing portion 23a enters
similarly to the above through the apertured portion
21c of the holder 21 into the interior of the holder 21 to
push the center core 3 along the spindle 8. Upon further
downward movement of the holder 21 in the direction A, the
pin 54 moves along the portion "n" in the direction K,
thereby the pressing arm 23 is turned in a counterclockwise
direction. Just when the pin 54 arrives at the portion "p",
the pressing arm 23 returns to the initial position, so
that its free end or pressing portion 23a moves away from
the center core 3.
On the other hand, when the holder 21 rises in
the direction B from its downmost position, the pin 54
moves along the groove 55 from the portion !'p" to the
portion "q" in the direction L. Since, in the portion
indicated by "q", the depth of groove 55 becomes shallower,
the slide lever 51 slidingly moves toward the front of
the paper against the spring 52. When the top end of
the groove 55 indicated by "r" is reached, the slide
lever 51 moves toward the back of the paper by the spring 52,
thus regaining the initial position. During the movement
of the pin 54 in the direction L, the arm 23 remains
stationary. By the process through a series of these
operations, it is made possible similarly to the aforesaid
first and second embodiments to actuate the pressing arm 23
in response to downward movement of the holder 21, thereby
the center core 3 is pushed onto the spindle 8, and
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'~ereafter to remove the pressing portion 23a of the
pressing arm 23 from the center core 3.
Here in the first to the third embodiments des-
cribed above, for example, the following variations are possible.
For example in the apparatus of the type in which
the cassette holder 21 is automatically moved upward and
downward by an electric motor as the drive source, the power
of this drive source may be utilized in operating the
pressing arm 23 in such a manner that after the center core 3
is set on the spindle by the pressing arm 23, the pressing
arm 23 is returned to the initial position. Also though
the foregoing embodiments have been described in connection
with such an arrangement of the pressing arm 23 that it is
at a time during the loading operation of the magnetic disc
cassette 2 that the free end or pressing portion 23a of
the pressing arm 23 departs from the center core 3, another
different arrangement may be employed such that it is after
the cassette loading operation has been completed that
the pressing portion 23a leaves from the center core 3.
For example, in the second embodiment, the cam portion 23e
of the pressing arm 23 in Fig. 6 may be otherwise formed
to such a shape that the cam lift gradually increases as
it goes from above to below as viewed in the drawing, and
then suddenly decreases from its maxirnum position. In
the third embodiment, the shape of the groove 55 may be
modified from the letter "D" to a right triangle facing
toward the right as viewed in the drawing.
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A fourth embodiment of the present invention (Figs. 9 to 11):
In Figs. 9 to 11, the same reference characters
have been employed to denote the parts having fundamentally
similar structures and functions to those of the parts
shown in Figs. 1 to 8, and their explanation is omitted.
The pressing arm 23 is here modified with its
tail end portion having a slot 23g in which engages the
shaft 24 on the chassis 25. Besides its capability of pivotal
movement about the shaft 24, therefore, the pressing arm 23
can also move linearly along the slot 23g in the longitudinal
direction thereof. A spring 63 urges the pressing arm 23 to
move in a direction of arrow R so that the shaft 24 is normally
in contact with the left hand side of the slot 23g (Fig. 9).
The opposite end of the spring 63 is fixedly attached to a
chassis 64. 61 is a cam used instead of the lever 26
in Figs. 3 to 5 and fixedly mounted on the pressing arm 23.
The position of the cam 61 relative to the pressing arm 23
can be adjusted by slits cut therein and fastener screws
engaging in the respective slits. Though two pairs of slit
and screw are shown, its number is not limitative. With
this cam 61 on the pressing arm 23 cooperates a lever 29
similar to that shown in Figs. 3 to 5 in such a manner
that when it turns in a counterclockwise direction
(direction D in Fig. 10), its free end portion 29a abuts
on a camming surface 61a of the cam 61, and when it turns
from the below in a clockwise direction (direction F in
Fig. 11), its free end portion 29a abuts on another camming
surface 61b of the cam 61.
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The other parts than the above are fundamentally
similar in construction to those of the first embodiment.
With such construction, after the magnetic disc
cassette 2 has been inserted into and seated in the
holder 21, when the holder 21 is moved downward or in
the direction A in Fig. 9, as the holder 21 moves downward,
the pin 31 engaging in the slotted portion 21b of its
extension 21a moves in the direction A thereby the
lever 29 is turned in the direction D in Fig. 9. Therefore,
the free end portion 29a of the lever 29 abuts on the
camming surface 61a of the cam 61. And since the cam 61
is fixed to the pressing arm 23, the pressing arm 23 then
turns about the shaft 24 in the clockwise direction.
Thereby its free end or pressing portion 23a advances past
the apertured portion 21c of the holder 21 into the interior
of the holder 21 to push the center core 3 along the
spindle 8. This operative position is illustrated in Fig. 10.
It is to be noted that in the position of Fig. 10, the
pushing of the center core 3 is not yet finished. Therefore,
a gap Q is left between the lower surface of the center
core 3 and the upper surface of the flanged portion 8a
of the spindle 8. Then, upon further downward movement
of the holder 21 in the direction-A, the lever 29 further
turns in the direction D which also causes the pressing arm 23
to further turn in the clockwise direction while further
pushing the center core 3, finally bringing the lower
surface of the center core 3 into abutting contact with the
upper surface of the flanged portion 8a of the spindle 8
with the removal of the aforesaid gap Q.
~ 3 ~
Even when the holder 21 further moves downward
from this position, the pressing arm 23 can no longer turn
in the clockwise direction, but the lever 29 is allowed
to further turn in the direction D. Therefore, khe pressing
arm 23 is moved to the left along the slot 23g of its tail
end portion against the spring 63 by the leftward directional
force component of the pressure on -the free end portion 29a
of the lever 29 in reaction to the camming surface 61a of
the cam 61. As a result, the free end portion 29a of the
lever 29 moves away from the cam 61. Thereby the pressing
arm 23 is turned in the counterclockwise direction by the
bias force of the spring 32~ returning to the initial
position defined by the stopper member 33.
By the way, because of the form tolerances of
the pressing arm 23, the free end portion 29a of the lever 29
and the cassette holder 21 and the location tolerances
of the pivot shafts 24 and 30 and the pin 31, it will often
happen that the pressure of the free end or pressing portion 23a
of the pressing arm 23 on the center core 3 becomes excessive,
or that even when the setting of the center core 3 has
finished, the free end portion 29a of the lever 29 does not
yet move away from the camming surface 61a of the cam 61.
If so, a so-called "wrenching" will result therebetween,
and a smooth loading operation is hindered from bein-g
performed. On this account, in the foregoing first to third
embodiments of the invention, such drawback has been eliminated
by giving elasticity to a portion (23c) of the pressing
arm 23. In this fourth embodiment, on the other hand,
the pressing arm 23 is provided with the longitudinally
- 22 -
~ 3.~
longated slot 23g at the tail end portion thereof, and
it is at this slot 23g that the shaft 24 is made to cooperate
in engagement therewith, so that when the resistant force
(reaction) from the center core 3 to the pressing arm 23
exceeds a certain limit, the pressing arm 23 is caused to
move to the left against the bias force of the direction R
by the spring 63. Therefore, the free end portion 29a of
the lever 29 smoothly departs from the camming surface 61a
of the cam 61, and the pressing arm 23 immediately turns
in the counterclockwise direction to the initial position.
This enables the apparatus to be loaded with the magnetic
disc 1 smoothly and safely.
When to take out the cassette 2 from the holder 21,
the reverse operation to that in which the holder 21 was
moved downward in the direction A is carried out, so that
the holder 21 moves upward in the direction ~ in Fig. 11.
Such upward movement causes the pin 31 to be also moved
upward. Therefore the lever 29 is turned about the
shaft 30 in the direction F. Its free end portion 29a
is brought, at this time, from the below as viewed in the
drawing into abutting contact with the camming surface 61b
of the cam 61. In this case, too, the pressing arm 23
moves to the left against the bias force of the spring 63.
Therefore, the free end portion 29a of the lever 29
smoothly departs from the camming surface 61b of the cam 61,
returning to the initial position of Fig. 9. In this position,
the cassette 2 can be tal~en out or the holder 21.
- 23 -
A fifth embodiment of the presen-t invention (Figs. 12 to 14):
The fifth embodiment employs a toggle or snap
spring mechanism responsive to excess of the resistant
force (reaction) from the center core to the pressing member
above a certain limit for allowing the pressing member to
escape to a different direction from the pressing one.
In Figs. 12 to 14, the pressing member comprises
a base portion 71 and a movable portion 72 which is
pivotally mounted at a shaft 73 planted on the base portion 71.
72a is a free end or pressing portion of the movable portion 72
having a function of pushing the center core 3 similar
to the free end or pressing portion 23a of the pressing arm
23 in Figs. 3 to 11. 74 is a toggle or snap spring of
which one end is fixed to a support portion 75 provided on
the base portion 71 and the opposite end of which is fixed
to an extension 76 provided on the movable portion 72. 77
is a position limit pin for the movable portion 72 and is
planted on the base portion 71. 78 is a pin planted on
the base portion 71 and engaging in a slot 21b of the
extension 21a of the cassette holder 21. 36 is a
limit portion for the movable portion 72 provided in the
chassis 25. Of the other parts, those denoted by the same
reference characters as in the foregoing drawings have
similar constructions and functions to those precedingly
illustrated, and the cassette holder 21, motor 7, spindle 8
and magnetic head 10 though not shown here are similarly
constructed and arranged to the above.
With such construction, when the holder 21 is
moved downward in the direction A from the position of
- 24 -
~ 3 ~ ~ L,~ ~ ~
~ig. 14, the pin 78 planted on the base portion 71 moves
downward, thereby the base portion 71 and the movable
portion 72 are turned about the shaft 24 in a clockwise
direction, while simultaneously the free end pressing
portion 72a of the movable portion 72 pushes the center
core 3 along the spindle 8. Here, if the resistant force
(reaction) from the center core 3 is below a certain limit,
the toggle or snap spring 74 is in a first stable position,
maintaining th~ movable portion 72 in a relative position
shown in Fig. 12 to the base portion 71. As the base portion 71
and movable portion 72 further turn to finish the setting
of the center core 3 on the spindle 8, when the resistant
force from the center core 3 then exceeds that certain
limit, the toggle or sanp spring 74 transits to a second
stable position as illustrated in Fig. 13, thereby the
movable portion 72 is turned relative to the base portion 71
in the direction H in the drawing, thus escaping to a
different direction to the pressing direction. Therefore,
the free end or pressing portion 72a leaves the center core 3.
This leads to realize a stable loading operation.
On the other hand, the cassette holder 21 is
moved from the downmost position in the direction B for
the purpose of taking out the cassette 2. As the pin 78
moves upward, the base portion 71 is caused to turn in
a counterclockwise direction. At a point during this
counterclockwise movement of the base portion 71, the movable
portion 72 abuts on the limiting portion 36. After that,
the movable portion 72 turns relative to the base portion 71
in the reversed direction to the direction H. And, at a time
~ 3 ~
during this rotative movement of the movable portion 72,
~he toggle or snap spring 74 transits to the aforesaid
first stable position. Thus, the movable portion 72
returns to the relative position shown in Figs. 12 and 14
to the base portion 71. Then when the holder 21 reaches
the predetermined position, the initial condition shown in
Fig. 14 is regained.
For note, instead of the aforesaid toggle or snap
spring mechanism, a click mechanism may be used to effect an
equivalent result.
It is obvious that any of the first to the
fifth embodiments described above is not incompatible with
the simultaneous use of coupling means based on the magnetic
force in the center core 3 and the flanged portion 8a of
the spindle as in the prior art, and the first to the
fifth embodiments are applicable to the conventional apparatus
described in connection with Figs. 1 and 2 without any
alternation.
As has been described in greater detail above,
according to the present invention, by a simple mechanism
it is made possible to set the record bearing medium on
the rotating drive portion accurately and to assure that
the record bearing medium is always well aligned to the
recording and/or reproducing head. Particularly because the
center core of the record bearing medium is usually made
of plastics, for easy fitting on the rotating drive, the
tolerance of its inner diameter is large. The use of the
above-described mechanism provides the possibility of
designing its inner idameter to be rather smaller so that
- 26 -
~he tolerance on the inner diameter of the center core
has far lesser an influence on the accuracy and reliability
of location control as the pressing mernber works when the
record bearing medium is loaded. This feature is suited
to the mass production also.
Also since the operation of that mechanism is
controlled in such a manner that the aforesaid pressing
member is first actuated to bring the record bearing
medium into fitting engagement with the rotating drive means
and thereafter this pressing member is removed from the
record bearing medium, it is during recording or reproduction
that the pressing member never adds any load on the
rotating means, thereby giving an advantage of reducing the
size of the rotating means.
Also in particular, as illustrated in the first
to the third embodiments, the pressing member is given
elasticity in a portion thereof, or as illustrated in the
fourth and fifth embodiments, the pressing member is so
constructed and so arranged that when the resistant force
(reaction) from the record bearing medium acting on the
pressing member exceeds a certain limit, the pressing
member escapes to a different direction to that pressing
one, thereby always safe and smooth loading operation
can be realized despite there are the form tolerances and
location tolerances of the pressing member or those members
which constitute the operating mechanism therefor.
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