Note: Descriptions are shown in the official language in which they were submitted.
PHD 80.043 l 1.3. 1~81
Drive appara-tus for ~le~ible record carriers'l.
The invention relates to a drive apparatus for a
~lexible record carrier with a central hole~ in particulc~r
~or magnetic disks contained in enclosures, which apparatus
comprises
- a frame with an entrance opening ~or a record carrie.r,
- a drive mechanism for a turntable which is rota-table
about an axis of rotation, which mechanism comprises a
bearing housing ~or the turntable 9 which housing is secured
to the ~rame,
a disk~clamping member which is arranged to be rotatable
about -the axis of rotation of the turntable and which is
a~ially movable relative to said -turntable between an
operating position and a lifted position,
- a s-tationary bearing member which carries a guide spindle
for the disk-clamping member~
- a cover which is pivotable relative to the ~rame for
closing the entrance opening, and
- a lever mechanism which is arranged between the cover
and the disk-clamping member and which is force-coupled
thereto, for moving the disk-clamping member in accordance
with the movament of the cover.
From DE-OS 27 16 848 a drive apparatus is known
in which the c:over together with a roller and clamping-
lever mechanism as well as with the lifting part of the
drive mechanism including its spindle, constitute an inter-
changeable assembly, which is connected to the rest of the
apparatus as a unit~ The pivotal axis of the cover is
situated at the upper edge, so that after opening the
cover it projects comple-tel~ from -the drive apparatus and
impedes the insertion and removal of the fle~ible record
carrier. Fur-thermore, the rollar which is connected to -the
cover is arranged so that in any operating position of the
PHD 80.043 2 1.3.1981
cover it is posi-tioned on -the upward slope of -the
clamping lever and is moved only s]ightly on said slope.
In order -to ensure that the record carrier is correctly
centred and is firmly positioned in the drive mechanism,
the lifting part o~ the drive mechanism is formed as a
cone and is urged against -tlle sta-tionary part by a
compression spring which is compressed by the clamping
lever. As this spring force is compara-tively great, the
clamping lever should also exert a comparatively great
f`orce on said spring. As a result of this, a continuously
increasing pressure sho-uld be exerted on said cover when
it is to be closed. Therefore, the cover should be of
very stable constructionO Moreover, such a drive apparatus
cannot be incorpora-ted in light--weight equipmen-t, because
this would slide away when -the cover is closed if no
co~-mter-acting force were exerted on the equipment.
Furthermore? owing to the separation of the spindles of
the two parts of the drive appara-tus9i-t is no-t unlikely
that these will no-t be in line owing to manuf'a_turing
tolerances or wear effects 9 which may impair the correct
retention of the fle~ible record carrier.
Furthermore~ a drive apparatus is known from US-
PS 3.940.793, in which the cover comprises a lever with a
downwardly curved slopeg which upon actuation of the cover
runs between two rollers of the clamping lever and then
pivo-ts said lever about a pivotal axis, This drive
appratus is very intricateO The cover as well as its lever
cannot be made comparatively thin and -thus cannot b0 manu- !
factured in a simple manner9 because, although the clam-
ping lever does not act on a compression spring, -the to-tal
pressure for clamping the record carrier in the drive
mechanism is to be produced by -the lev0r of the cover. Thus,
-the force required for clasing the cover will also s-teadily
increase with this construction.
It is the object of -the invention -to provide a
drive appara-tus, l~hose cover can be actuated with a
constant and small force without complicating the construc-
PTID 80. ol~3 3 1 . 3 . 198 l
tion. Moreover, the drive elements and the clamping cone
should be easy -to molmt in orcler to guarantee that -these
elemen-ts are correctly jou:rnalled on spindles which are
in line wi-th each other.
This object is achieved in -tha-t both -the stationa
ry bearing member for the guide spindle and a stationary
fixing member for the bearing housin~ of the turntable
form integral parts of the frarne, and the bearing housing
is in-troduced in-to and secured -to -the frame from -the out-
side. Sui-tably9 the fix.ing member for -the bearing housing
-takes the form of a bush and the bearing housing is provi-
ded with a flange and is secured to an end surface of the
bush~ This makes it possible to machine the bearing bush
for the drive element and the bearing for the guide spindle
for the clamping cone in one operation into the i.ntegral
frame.
In accordance wi-th a further embodiment of the
invention the frame has a portion which slopes downwardly
towards the exterior over at least a part of the width of
2~ the ~rame at the location of the entrance opening for
the record carrier. Similarly, the cover comprises a
projecting portion which extends over at least a part of
the width of the coverO Thus, the sloping portion and the
projecting portion constitute a funnel for the insertion
25 of the record carrier in the open position of the cover.
This facili-tates insertion of the record carrier and
said record carrier is automatically guided in the space
between the turntable and the clamping cone.
In accordance with a further embodiment of the
30 invention~ for the force-coupling of the lever for moving
the clamping cone to the cover, the lever comprises a
sligh-tl~ curved extension, over whi~h a roller arranged on
the projecting por-tion of the cover rolls upon actuation
o:E the cover.
Since -the roller rolls over the ex-tension as the
cover is close~l, the lever arm relative to the pivotal axis
of the lever is continuously extended and the poin-t of
PHD 80.043 ~ 1.3 1981
contac-t o~ -the roller with the extension is shi~-ted
so relative -to -the pivo-tal axis o~`-the cover, that as
the entrance opening is further closed the required ~orce
remains substantially constan-t or increases only to an
insigni~ican-t extentO
The invention will be described in more detail
with re~erence -to -the drawings, which shows an embodimen-t.
In the drawings-
Fig. 1 is a perspective view o~ a drive apparatus
wi-th open cover and a record carrier arranged in ~ron-t of
it,
~ ig. 2 is an explo~ed perspec-tive view o~ the
drive apparatus 7
Fig. 3 shows the drive apparatus partly in
sectional view, and
Fig. ~ is a vie~ against the rear sicle o~ the
cover o~ -the apparatus.
The drive mechanism ~or a ~lexible record
carrier, which comprises a magnetic disk 10 and an enclo~
sure 18 surrounding it, is mounted in a ~rame 25 which is
~ormed by a casting. The drive mechanism, which is shown
in sectional view only on one side o~ the axis o-~ symmetry
in Fig. 3, comprises a drive part and a li~ting part, which
is constructed as a centring or clamping cone 9. The
driv~ part comprises a -turntable 11 and a bearing housing
2~ with a drive pulley 27, ~hich is driven in known manner
by an electric motor via a belt. The bearing housing com~
prises a ~lange 26, by means o-~ which the bearing housing
~its exactly in a fixing member 23 ~ormed by a bush.
~y means o~ lugs 28 the bearing housing i9 detachably
mounted on the ~ixing member 23. The inner ~ace of the
bush is formed in -the integral rrame 25 by a milling
operation such tha-t its axis is in line with -the axis o~ a
guide spindle 17 ~or the clamping cone 9. This is achieved
in an e~ective manner i~ the bush and a precision ~i-tting
bush 29 ~or the guide spindle 17 have their respective
inner ~aces machined in one operation into the in-tegral
,.
PHD 800043 5 1.3.1981
frame~ The bush 29 is connected -to the remainder Or
the frame by a rigid par-t 1 pro-truding from and integral
wi-th the remainder of the ~ame.
The ~iameters of -the -turntable 11 and the
clamping cone 9 are smaller -than the bush diame-ter9 so
that the entire driven par-t after i-ts assembly, and -the
clamping cone 9, af-ter mounting of the guide spindle 17,
can be inserted into the ~rame 25 through the fixed member
23 from underneath and can be secured therein.
The clamping cone 9 comprises a sleeve 20, by
means of which -the cone can be slid up and down the guide
spindle 17. This sliding movement is obtained by means of
the fork shaped construction of -the front end of a
clamping lever 7. In the opera-ting posi-tion of s~id lever
7, shown in Fig~ 3, pressure is exerted on a compression
spring 8 surrounding the sleeve 20, which spring in turn
urges the clamping cone 9 into the turntable 11 of -the
drive mechanism and thereby centres and clamps the flexi-
ble record carrier 10 in the drive mechanism. In this
position of the clamping lever 7 a return spring 14 is
tensioned, which spring is secured to the clamplng lever 7
and to the frame ~5~ Before the cover 2 is fitted the
clamping lever 7 is mounted through the entrance opening
of the apparatus. It is inser-ted through the opening un-til
its ~ork-shaped leading end 30 engages the sleeve 20 be
tween an abutment 22 on the sleeve and the upper end of
the compressi:on spring 8. Subsequently, a bearing spindle
15 is laterall~ inserted in-to a corresponding sea-ting in
the frame. The clamping lever 7 is pivotable about said
bearing spindle 15 by ac-tuation of the cover.
When -the cover 2 is pivoted about i-ts pivotal
axis 3 into the position represented by broken lines in
Fig. 3, the clamping lever 7 is released~ This lever
yields to the pressure of the spring 8 until the fork-
shaped end 30 engages wi-th the abutment 22. Su~sequently,
the return spring 14 p:ivots said lever, together with
the sleeve 20 and the clamping cone 9, in-to the position
PHD 80.043 ~ 1~3.1981
which is only partly rep~esented by broicen lines~
l~hen a n.ew record carrier 10 is to be insertecl,
this can be done wi-thou-t any risk owing -to the presence of
the two inclined projecting portions 4 and 5, because there
are no impediments and the record carrier 10 is ailtomatical--
ly guided by -the f~nnel-shaped open:ing thus formed. As can
be seen in ~ig. l~ which is a view of the cover 2 from the
interior of the frame, the inclined projecting por-tion 4
ex-tends subs-tantially over the full width of the cover 2
If the cover 2 is now pivoted from th.e open to
-the cl.osed position about its pivota.l axis 3, this is
initially ef~ected without any counteracting force until
-the roller 12 of the cover engages -the curved extension 19
of the clamping lever 7 at a contact poin-t 13 on the
15 extension 19. The dis-tance a of thi.s point from the bearing
spindle 15 of the clamping lever 7 is minimal. ~s -the cover
2 is pivoted further the clampinglever 7 is pivoted about
the bearing spindle 15. ~t the cover 2 only the compara-
tively small spring force of the return spring 14 has to
20 be overcome.
Upon a further pivotal movement the clampinglever 7 con-taets the compression spring 8, whose spring
force is greater than that of the return spring 14, so tha-t
from -this point a greater force would be required to
25 actuate -the cover if in the meantime the point of contact
be-tween the roller 12 and the clamping lever 7 had not
moved further away from the pivot of the clamping lever 7.
~s a result of this, the lever arm is extended, so that
with the same force exerted on the cover a greater spring
30 force can be overcome. The lever arm is extended until
finally the con-tact point 16 is reached, which point is
situated at a distance b from the pivota:L axis of the
clamping leverO In this position the cover 2 is closed and
can ba latched by means of the latching device 21. In the
present example the increase from the distance a to the
maximum dis-tance b is approxima-tely 1.5 to 2 times and can
readily be adap-ted -to specific conditions by means of the
springs 8 and 14. This ratio of forces becomes even more
PHD 80.043 7 1 3.1981
favourable because the distance be-tween the pivo-tal
axis 3 and the moving point of contact between -the roller
12 and -the clamping lever 7 rernains substantially cons-tant
during -the pivotal ~novemen-t o~ -the cover 2. For -this
S purpose -the extension 19 of the clamping lever 7 is
slightly curved.
As the pivotal axis 3 o~ the cover 2 is si-tua-ted
well inside the housing, the cover will not project ~ar
from the housing in the open position, so that the ejected
record carrier lO can readily be gripped.
A plastics front plate 6 can be snapped onto -the
frame 25 by means of clips 31 and 32~ Thus, when the drive
apparatus is to be incorporated in a housing 33 the front
plate 6 can be adapted to openings of any size. Moreover,
the cover 2 comprises a latching device 21, kno~l ~ se,
with which it engages behind a projecting portion o~ the
front plate 6 in the closed position. The cover can then
be unlatched by moving said latching device 21.
.
