Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
39
TITLE 1.
TOP LO~DI~G SWINGI~G BUCKET
CENT~IFVG~ ROTOR ~A~ING ~NIFE ED~E PIVOTS
Field of_the ~nvent on
~ hi~ invention relate~ ~o a eentrifuge rotor of
the swi~ging bucket type and, in particular, to a top
loading ~winging bucket centrifuge roto~ having knife
e~ge t~unnion pivot elements.
Des~riPtion o~ the Prior Art
A centrifuge rotor of the type in which a ~ample
~ontainer ca~cying a ~a~ple of the material to b~
eentrifuged moveg fro~ an initial po6ition in which
the a~ of th~ sa~ple container i8 5ub~tantiallr
parallel to the ~ertical ~enter line of the rotor to a
~econd posi~ion in whieh ~he axis o~ the sample
coneaineL lie$ 6nbstantially in a plane per~endicular
to the vertical cente~ line o the ~otor i6 known a~ a
swinginq bucket cotor.
In o~e typical arrangemen~, the ~am~le
container, or bucket, used with ~uch rotors typi~ally
includes outwardly ~rojecting elements, or trunnions.
having a portinn thereof de~ining a ~ub~tan~ially
cylind~ical bearing ~ur~aee. The tLunnion pin~ are
typically received in corresponding ~uppore arm~ that
are provided ~ith conforming trunnion receiving
socket~. Alternatively, trunnion pin~ ~ay be located
~25E~339
on the arm~ with the corre6ponding socket~ being
disposed on the container.
In either event the bearing ~ur~ace on t~e
trunnion pin bears again6t ~he su~ace of the trun~ion
receiving ~ocket in which it is ~eceived throughout
the pivotal movement of the ~ample container from the
ini~ial to the second position. The trunnion
receiving 60cket therefore act~ both as the ~urface
which ~upports the bearing ~urface on the trunnion pin
and ~he constraining and guiding ~urface which in6ures
the controlled movement of the sample container from
the initial to the ~econd po~ition~. United State6
Patent 4,400,166 ~Chulay et al.), United State~ Patent
3~393,864 (Gala~so et al.), United States Pa~ent
2~31053 (McCollin) and Swi8s Patent 296,421 (~illems)
di~close typical ~xamples of such rotors.
Trunnion pin sy6tems are generally complex and
c06tly. A sample container should preferably be a
lightweight structure to ~inimize cen~rifugal loading
on the rotor. However, the presence of trunnio~ pins
cantilevered from a sample container requires a
sub6tantial anchorage in the container structure,
neces6itating an unde~irable in~rease in the weight of
the container. In addition, when loading the ~ample
container into the ro~or thle presence of the trunnion
pin~ require locatiAg the container i~ a preci~e
orientation with respect to the rotor. This can
present, at a minium, an inconvenience to an
operator. M~reo~er, as is developed herein,
mi~orienting the container with respect to ehe rotor
can have more deleteriou~ consequence6.
The abrading action which occurs between ~he
bearing ~urface on the trunnion 2in and the 60cket is
also believed to be disadvantageoufi for ~everal
reasons. Fi~t of all, the abrasion re~ult~ in the
~i8~33~
wearing of metal which mus~ be clo~ely monitored. I'o
counteract this reGult hardened materials are used for
the pins and the supports. Furthermore, trunnion pins
require the ~t~uctures exhibit relatively large radii
in order to ceduce trunnion steess and contact stre6s.
In United S~ates Patent 4,435,167 (Stower) an
alternative support arrangement is disclosed which
eliminates the above-discussed abrading action by use
of a rolling profile to engender rolling action
between one or more profiled surfaces. However7 such
an arrangemant appeaLs to prevent orientation of the
container with its axi6 completely parallel to the
vertical axis of the rotor. A rolling profile
precludes the axis of the sample container from
reorienting to a true vertical position after
centrifugation. At zero rotational speed the sample
container will hang in a true vertical position only
if the line of restraint is directly in vertical
alignment with the cen~er of gravity of ~he sample
container on the centerline of the container. The
line of restraint i~ that location where the forces
acting on the center of mass of the container resist
movement. Likewise, under high 6peed rotation the
container will assume a horizontal orientation only if
the line of restraint i8 in the horizontal plane of
the center of gravity of the container. Since the
center of gravity does not change relative to the axi~
of the container and the use of a rolling profile does
alte~ the point of rest~aint relative to this axis,
the aboYe reguirements are mutually exclusi~e. Since
it is desirable in operation to ha~e the axis of the
6ample container align with the centrifugal force
field, it follows with the Stower structure tha~ as
the rotor 610ws and stops the axiG of the container
will not hang in a true vertical position. Thus. at
~S8~3g
'1
least in gradient operations, the possibility of
unsettling the gradient in the container exists unles6
the user, when removing the container, is careful to
keep it at the same orientation as existed when the
rotor stopped.
Accordingly, in view of the foregoing, it is
believed advantage~u~ ~o provide a mounting
arcangement for upporting the pivotal motion of the
~ample container from the initial to the second
positions which eliminates the shifting of the
container's line of restraint as exhibited by the
prior art.
As alluded to earlier. prior art trunnion
~ystems require that the sample container be
accurately oriented and mounted on the trunnions.
HoweveE, this requirement is not always fulfilled in
practice. Thus, sample containers are misplaced on
the rotor. The majority of rotor mishaps can be
traced to the misorientation of the sample container
on the rotor.
Furthermore, if ~uch a mounting arrangement is
provided which eliminates the disadvantages of prior
art trunnion system6 it is also believed advantageous
to provide a sample container especially configured to
complement that arrangement to its fullest advantage.
Accordingly it is believed to be of further
advantage to provide a top loading centrifuge rotor in
which the reguirement of container orientation with
respect to the rotor i8 totally eliminated. That is,
a rotor in which a sample container may be
expeditiously inserted without the necessity of
verifying the po~ition of the container with respect
to the rotor should be significantly advantageous in
reducing the occurrence of rotor mishaps.
! 4
~258~33~
SUMMARY OF THE INVENTION
The present invention relates to a centrifuge
rotor of the swinging bucket type and compriaes a pair
of sample container pivot elements disposed in
circumferentially spaced relationship about the
rotor. ~ach pivot element is arranged to define a
thin knife edge adapted to receive the pivot surface
of a sample container along a substantially line
contact. The rotor is arranged such that the sample
container may be loaded into the rotor from the top
without the nece6sity of orienting the container on
the pivot surfaces. That is, the container may be
inserted into the rotor such that any diametrical
dimension of the surface may lie coincident with the
line contact defined by the pivot edges.
A quide 6urface is disposed on the rotor
radially inwardly of the pivot element and cooperates
with the outer configuration of the sample container
to guide the same as it pivo~s with rotation of the
roto~ on the line of contact with the pivot elements
through a portion of its travel from the initial to
the second position. Preferably the pivot elements
are mounted within the rotor and designed such that
when the sample container reaches the second position
centrifugal force effec~s cause the pivot elements to
deflect to an extent which permit6 the ~am~le
containers to move radially outwardly and thereby
bring their radially outer surfaces into a force
transmitting rela~ion~hip with a stress confining band
which may be provided about the rotor. A stoe surface
communicating with the guide surface prohibits motion
of the sample container past the second position.
The present invention relates to a sample
container for use in a top loading centrifuge rotor of
the type having a pair of knife-like eivot edges
~5~33~
thereon. The container include~ a body membe~ having
a sample-receiving volume therein. The body carries,
at a convenient location thereon, a planar pivot
6urface which i6 adap~ed to operably engage each of
the pivot edges for ~upported pivotal movement from a
first to a second position. Prefe~ably the container
includes a cap threadily or otherwise connectable
thereto which carries the planar surface. The planar
surface preferably engages the knife-like edges along
an interrupted line contact that extends diametrically
of the cap and intersect~ the longitudinal axis
thereof. Any diametrical dimension of the surface may
be aligned with the line of contact, thu~ avoiding the
nece~sity of orienting the container with respect to
the rotor~ The cap may, in the preferred case, carry
a guide ~in arranged to cooperate with a
correspondingly guide slot di~posed on the rotor at a
point radially inwardly of the pivots. The 6top pin
i8 al60 arranged to coo~erate with an arresting
~urface provided at a convenient location on the ~otor,
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from
the following detailed de~cription thereof taken in
connection with the accompanying drawing~ which form a
part of thi6 application and in which:
Figure 1 is a plan view of a top loading
~winging bucket centrifuge rotor in accordance with
the preferred embodiment of the invention;
Figure 2 i8 a 6ectional view taken along section
lines 2-2 of Figure l;
Figure 3 i8 a view similar to a portion of
Figure Z showing a ~ample container in the second
po6ition with ~he pivo~ 6upport element in the
deflected condition;
12S~83~
Figure 4 is an elevational view of the sample
container used in each embodiment of the pre~ent
invent,ion with portions broken away for clarity
Figure 5 is a side 6ectional view of a 6ample
container ca~rying assembly in accordance with another
embodiment of the invention;
Figure 6 i8 a view similar to ~igure 5 showing
the sample container carrying assembly with the pivot
~upport element in the deflected condition; and
Figure 7 is a plan view of a to~ loading rotor
having an acray of sample container carrier assemblies
as shown in Figures 5 and 6.
DETAIL~D D~SCRIPTTON OF THE INVENTION
Throughout the following de~ailed descrip~ion
similar reference characters refeL to similar elements
in all Figures of the drawings.
With reference to Figure~ 1 and 2 respectively
shown is a plan view of a portion of a top loading
centrifuge rotor generally indicated by reference
character 10 embodying the teachings of the present
invention and a side sectional view of ~he same.
The rotor 10 includes a generally annular core
14 that receives in driving engagement a drive adapter
16. The drive adapter 16 ser~es as the interconnecting
element through a shaft S whereby the rotor 10 is
connected to a centrifuge drive motor M (shown
schematically) to rotate the rotor 10 about its
~rtical axis 1~. Of course, any suitable form of
interconnection between the rotor 10 and its motive
source may be used.
The coLe 14 i6 fabricated of material such as
aluminum, titanium or pla~tic. The core 14 serves to
locate and transmit torque to those elements (to be
described) disposed outwardly therefrom. The core
fihould be as lightweight as possible in order to
~2~il383S~
maxirnize its strength to weight eatio and to minimize
stresses during high speed rotation. To decrease the
weight the core 14 is provided with array~ of CUtOlltS
22 and 24 on its upper and lower surfaces
respectively. The outer peripheral ~urface of the
core is stepped as at 26 (Figure 2) ~o define upper
and lower cylindrical portions. The upper cylindrical
portion and the lower cylindrical portion are each
provided wi~h a notch 28 and 30, respectively. Each
of the notches receives a supporting wrapping 32 and
34, respectively. The wrappings 32, 34 are fabricated
of a composite fiber material ~uch as an aramid fiber
manufactured and sold by E. I. du Pont de Nemours and
Company under the trademark XEVLAR~. Each fiber is
impregnated with a resinous material, such as epoxy or
the like, and wrapped to form stre~s confining
wrappings 32, 34 to enhance the strength-to-weight
ratio of the co~e 14. The wrappings 32 and 34 may, of
course, not be necessary if the core material is
itself a sufficiently high-strength matecial, as
titanium.
An array of spherical cutouts 38 is arranged
around the periphery of the lower cylindrical portion
of the core 14. Communicating with the head of each
cylindrical cutout is a sub6tantially cylindrical
channel 42. The purpose of the cylindrical channels
42 will be dascribed in more detail herein. Intergosed
between adjacen~ ones of the cutouts 38 are rectangular
notches 44 tFigure 1) for a purpose which will be also
set forth herein. The number of cutout~ 38, channels
42 and notches 44 corresponds to the number of 6ample
containers carried by the centrifuge rotor lO.
Refecring to Figure 4 shown in side elevation
with a portion broken away is a sample container 48
used with the pLesent invention. The sample container
~Z58~335~
48 has a longitudinal axis 48A and includes a
substantially cylindrical body portion 50 threadily
attached to a cap 52. The body 50 is a substantially
tubular member preferably machined from titanium or
other suitable ma~erial. The u~per end of the body 50
is provided with external threads 54. The lower end
of the body poction 50 flares ~hrough a frustoconical
region 56 to a stress distributing spherical end
region 58. The radius of the spherical end 58 matches
that of a force distributing member 110 di~posed about
the outer periphery of the rotor. The interior of the
body portion 50 is configured with cylindrical
sidewall 60 with a spherical end 62 which combine to
provide a typical test tube shape to the interior of
the body 50. Of course, the contouc of the interior
of the body 50 may take any desired shape.
The cap 52 is a hemispherical member, preferably
fabricated from nylon or other suitable material,
having an internally threaded bore 64 adapted to
LeceiVe the external threads 5~ of the body 50. The
annular planar undersurface 66 of the cap 52 defines a
pivot surface operative in a manner set forth herein.
The exterior surface of the cap 52 defines a surface
68 topped by an axially extending cylindrical stop pin
70. The pin 70 al80 conveniently serves a6 a handle
for the container ~8. The contour of ~he ~urface 68
corresponds in ~hape to the shape of the surface of
the spherical cutouts 38 provided in the core 14.
Similarly, the exterior contour of the pin 70 conforms
to the contour of the cylindrical channels 42 provided
in the core 14.
A~ seen with reference to Figures 1 and 2
arranged circumferentially about the core 14 is an
array of force transmitting segments 74 preferably
formed from a strong, light weight material, such as a
lZ5~33~
polyester engineering thermoplastic resin such as that
manufactured by E. I. du Pont de Nemvurs and Company,
and sold under the trademark RYNITE~. Each segment 74
i5 a substantially sector or wedge shaped member
having generally radially extending sidewalls 76 which
taper through converging curved portions 78 towards a
generally cectangular key yortion 80. Each key
portion 80 is configured f OL a close fitting
relationship with one of the notches 44 peripherally
arcallged about the core 14. The segment 74 is cut-out
to form a recess 82 to eliminate that extra mass
unnecessary to the performance of its pivot support
and s~ructural interconnection functions, as will be
desc~ibed. The recess 82 formed on the segment 7~
defines a pair of generally radially extending struts
85 joined by an arcuate connecting land 86. The end
of each strut 85 is stepped at its radially outer end,
as at 90, for a purpose made clear herein.
As perhaps best seen in Figure 3 in which a
portion of the sample container 48 is broken away,
each sidewall 76 of a segment 74 is provided with a
step 92 defined by a substantially ve~tical planar
shelf 93, a hori20ntal shelf 94 and a radially planar
portion 96 (Figure ~) extending radially inwardly from
sidewall 76. A notch 98 (Figure~ 2 and 3) is provided
into the 6tep 92 to receive and to secure one end of a
resilient pivot element 100.
The pi~ot element 100 is formed of a high
strength ~efiilient material, such as stainless sp~ing
steel or the like, and takes the form when in its
developed state of a rectangular s~rip 101. one end
of the strip 101 i6 inserted into the notch 98 and is
secured thereto by any suitable means of attachment.
The ~trip 101 is bent at a lower elbow 102 adjacent
the lower surface of the step 92 and slants vertically
~25~839
and radially inwardly to a ~econd, upper. bend 104,
whereat the strip 10l is bent backwards to define a
portion 106 which ove~lies the fihelf 94 of the step
92. The upper bend 104 of the strip 101 defines a
thin knife edge-like pivot sup~ort for the sample
container ~8. The undersurface of the StLip 101
in~ermediate the bends 102 and 104 defines a
predetermined clearance space 108 (Figure 2) with the
vertical planar face 93 of the step 92 fOl a puLpose
discussed herein. The knife edge-like pivot support
may be defined in a variety of ways. One such
alternative i6 described herein in connec~ion with
Figures 5 through 7. Any other alternative
constructions whereby the knife edge pivot support is
defined are to be understood as lying within the
contemplation of the present invention.
The circumferential distance between the
radially outer ends of the struts 65 of adjacent
segments 74 is closed by a shell-like distributor
element 110. The circumferential ends of the shell
110 are received in the steps 90 provided on
confronting struts 85 on angularly adjacent segments
74. The inner surface of the distributor shell 110 is
concavely spherical, as seen from Figures Z and 3.
The ~hell 110 i8 preferably fabricated in a honeycomb
fa6hion from eerforated sheet6 of aluminum bounded by
solid shaped plates o~ aluminum. Any other suitable
construction may be used.
Adiacent segments 74 are keyed into the
corresponding notches 44 on the core 14 to define the
circumferentially spaced array thereof. The spaces
between confronting surfaces 76 of angularly adjacent
6egments 74 together with the dist~ibutor 110
cooperate to define a pocket or region 112 adapted to
receive and support a sample container 48 during
~2S~3~39
12
rotation thereof. As di~cussed herein, the pocket 112
is accessible to an operator for top loading of a
sample container 48.
The above structural elements of the rotor are
maintained in their described assembled relationship
by circumferentially extending band 116 of fiber
composite material, ~uch as the acamid fiber similar
to that used to form the wrappings 32 and 34. The
wrapping6 3Z and 34 as ~ell as the band 116 are formed
of a composite ~aterial such as an epoxy coated aramid
fiber manufactured and sold by E. I. du Pont de Nemours
and Co. Inc. under the trademack KE~LAR~. The fiber
is uniformly traversed over the dimension of the
member through that number of tu~n6 required for a
given radial depth. The assembly is then placed in an
autocla~e and the temperature elevated to a suitable
level and held for a predetermined time to cure the
epoxy. Of course, any other suitable wrapping
~aterial and/or means of wrapping or banding the rotor
may be utilized. Each fiegment 74 serves ~o c~nnect
the cadially outer distributor plates to the core and
thus serves as structural interconnection for the
rotor much like the ~pokes of a wheel interconnect the
rim to the hub. A cover 118 may be connected to the
rotor, a~ by a threaded connection, if de~ired.
In operation, a sample of material to be
subjected to a centcifugal force field is introduced
into t~e interior of the sample container 48 and the
cap 52 thereof secured to the body portion 50. Sample
containers 4B are top loaded in a balanced manner into
diametrically opposed ones of the pockets 112 arranged
around the periphery of the rotor 10. Each container
48 is supported in its pockei 112 along an in~errupted
line contact 122 shown in Figure 1 by the characters
122A and 122B. The interrupted line of contac~ 122 i8
~æs~39
13
defined between the knife edge provided by the upper
bends 104 of the pivot support element pair 100
mounted on the step 92 on angularly confronting
sidewalls 76 of adjacent segments 74 and the adjacent
corresponding portion of the annular undersurface 66
of the cap 52 of the sample container 48. Preferably,
the line contact 122 so defined extends substantially
coincident with a diametrical dimension 68D of the
pivot surface 66 of ~he carrier 48. The dimension 68D
inteLsects the axis 48A of the container 48. Any one
of the diametrical dimensions defined across the pivo~
surface 66 may be coincident with the interrupted line
of contact lZ2. Alternately stated, the container 48
may be intcoduced into the rotor so that any diameter
of the pi~ot surface 66 aligns with the knife edge
pivots. The container 48 need not be oriented with
respect to rotor. Thus, the primary cause of mishap
-- misalignment of the sample container -- is avoided
using the teachings of the present invention.
With each container 48 in its initial position
(a6 shown in solid lines in Figure 2) motive force is
applied to the rotor causing the same to spin about
~he vertical axis 18. Increasing rotational speed
causes the sample container 48 to pivot on the line
contact 122 as above defined and to move from the
initial position in which the axis 48A o~ the 6ample
container 48 lies substantially parallel to the spin
axis 18 of the rotor to a second position (shown in
dotted lines in the left half of Figure 2) in which
the axis 48A of the container ~8 li~s in a plane
6ubs~antially perpendicular to the spin axis 18.
Throughout this pivotal motion only the interrupted
line contact 122 defined between the undersurface 66
of the head 52 o~ the sample container 48 and its
associated pair o~ pivot support elements 100 is
14
maintained. Thus, the point of restraint defined by
the line contact 122 remains the same throughout the
pivotal movement of the container 48. As a result
bo~h the abrading contact between the trunnion pins
and the sockets and the rolling action present in the
various prior ar~ swinging bucket rotors is
advantageously avoided.
Throughout its motion from the initial to the
second position ~shown in dot-dash lines in Figure 2)
the lower spherical end sa of the container 48 remains
radially inwardly of the inner spherical surface of
the distributor shell 110. Guidance of the sample
container 48 over a portion of its travel Erom the
initial to the second position may be effected using a
tructure similar to a portion of the ~tructure
di~cussed in connection with Figures 5 through 7.
Such guidance structure is provided in the rotor core
14 at a point radially inwardly of the pivot element
100. Motion of the 6ample container 48 beyond the
second (horizontal) position shown in Figure 2 is
arrested by the engagement of the cylindrical stop pin
of the container 48 into the corresponding
cylindrical channel 42 provided in the core 14.
The spcing element 100 is 6uitably designed to
deflect in such a manner that ~he container 48 is
sub6tantially horizontal before the 6pherical end 58
of the conLainer 4B contacts the inner spherical
sucface of the shell 110~ As the rotor ~pins, the
container 48 pivo~ while the ~pring 100 deflects.
Once horizontal the increasing centrifugal force on
the container 48 continues the deflection of the
spring 100 in a radially outwardly direction to close
the clearance gap 108 to thereby cause the undersurface
of the mid-portion oE the pivot element 100 to approach
into close adjacency to the vertical face 93 of the
14
~LZS~33~3
step 9Z. This brings the spherical surface 58 of the
sample container 4B into force transmitting contact,
shown at L23 (Figure 3), with the inner surface of the
distributor ~hell 110 and thereby into a force
transmissive relation~hip with the band 116 wrapped
around the rotor 10. By judiciously salecting the
material and geometry of the con~ainer 48 the
centrifugal loading on the band 116 from the container
48 ~hrough the distributor shell. llO i6 approximated
by the load imposed on the band 116 by the segments 74.
The abutment bet~een the bottom ~urface 58 of
the ~ample container 48, through the distributor shell
element 110, ha~ the tendency to more uniformly load
the band 116 and thereby prevent the imposition of
localized stresses on the band 116 which, in the
absence of the distributor elements 110 would appear
as essentially a small area contact between the
container and the band.
~ n view of the foregoing, those skilled in the
art having the benefit of the teachings of the pressnt
invention as set forth herein may effect numerous
modifications thereto. For example, it may in some
instances be desired to eliminate the cap 52 from the
container 48. In this instance the planar pivot
surface 66 may b~ provided in ~rly convenient manner on
the body member 50. As an example the body may be
~rovided with outwardly extending fins or the like
which carry the surfaces 6fi in a position thereon
app~opriate to coac~ with the pivot elements 100.
Likewise, the ~top element defined by the pin 70 may
be suitably implemented by appendages to the body 50.
These and other modifications are, however, to be be
construed as line within the scope of the present
invention as set forth in the appended claims.
~25~3g
16
An alternate embodiment of the invention i6
shown in Figures 5 th~ough 7. In this ~mbodiment the
sample container 48 i8 carried by a sample container
housing assembly 124 h~v;ng a fir6t and a second
housing elements 126A and 126B respectively joined
along a substantially radially, vertically extended
iointure plane 128. The inner ends of the elements
126 may take any shape but are pre~erably flat, as at
130 (Figure 7), ~o abut the co~e 14. The inner
su~face of each of the sample housing elements 126
contains a spherical surface 38' with a communicating
rotation arresting surface 42'. When vertical surfaces
132A and 132B cooperate to define a guide slot which
receives the pin 70 to guide the container 48 over a
portion of its travel from the initial to the second
posi~ion. In the embodiment of Figure6 1 through 4
the guide slot may be defined using upwardly and
radially outwardly slanting fins connected to the hub
at each side of the channel 42 to define a guide slot
which receives the pin 70 a~ the container 48 pivots
and guides the pivoting motion over a portion of its
travel from the initial to the second position. The
vertical slot 132 communicates with the channel 42' to
limit movement of the pin 70 on the container 48.
Cantilevered from the lower surface of each
housing element is a resilient leg 134 which has
defined, at the upper end thereof, the knife-like
pivot support edge 104'. Each housing ele~ent 126 has
a recessed portion 136 therein which, when conjoined,
define a volume in which the sample container 48 may
pivot. The leg 134 is designed to deflect to produce
the action similar to that discussed in connection
with the spring 100.
In the initial position (Figure 5) the leg 134
is radially spaced by a distance 108' from the
16
` ~5~3839
structure of the housing element 126 in which it is
disposed. The sample con~ainer 48 i6 received on the
pivot edges 104~ of the spring legs 134 in each of the
cooperating elements 126 and it is on the6e edges that
the inter~upted line of contact 122 i8 defined o~
which the container 4~ pivots from the first to the
second position and, after a predetermined pivotal
motion the pin 70 enters the guide slot 132. As the
container 48 pivots the leg 134 deflects radially.
once the container reaches the second position
continued rotation of the rotor causes the spring legs
134 to continue deflecting radially outwardly thereby
to close the distance 108' to bring the spherical
bottom surface 58 of the container 48 into force
transmissive contact with the housing 126 as shown by
the character 123" in Figure 6.
The exterior of the sample container housing 126
i8 appropriately configured for receipt into the
rotor. Any convenient configuration may be selected.
ln the embodiment 6hown in these Figuees 5 through 7,
t~le rotor includes a bowl-shaped receptacle 138 joined
at its cçnter to the core 14. The bowl-like
receptacle 138 is pLovided with a cylindrical sidewall
142 which lead~ to a flared fru6toconical surface
144. The exterior of the conjoined housing assembly
126 matches these contours. The cylindrical sidewall
142 defines a band 116~ functionally similar to the
band 116.
I~ view of the foregoing, those skilled in the
act having the benefit of the teachings of the present
invention as set forth herein may effect numerous
modifications thereto. These modifications are,
however to be be construed as line within the scope of
the present invention as set fo~th in the appended
claims.
