Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
lZ~S~;2
TITLE IP-460
A CENTRIFUGE ROTOR
H~VING A FLEXIBLE CARRIEP~ -
WITH RESTORING CAP ASSEMBLY
5BACKGROUND OF THE INVENTION
Thi6 invention relates to a rotor for a
cen~rifuge and in particular to a ~winging bucket
centrifuge rotor whi~h includes a flexible carrier and
which ha6 a re~toring cap as6embly opeLative to restore
the ~ample carrier to a po6ition in which the axi6 of
the 6ample container 6upported by the sample carrier
lie6 substantially parallel to the axi6 of rotation of
the rotor.
15DESCRIPTION OF THE PRIO~ ART
Swinging bucket centriEuge rotors are well ~nown
in the art. Such devices are operative to expo~e a
liquid fiample di6po~ed within a ~ample containe~ to a
relatively high centrifugal force field. Such rotor~,
when u6ed in device6 generally known as "ultracentri-
fuge~, may be eitheL of the fixed angle or the
6winging bucket type.
~ ith a 6winging bucket-type centrifuge rotor the
sample container6 are ~upported within carrier6 which
are oriented 6uch that in an initial po6ition the axi6
of each carrier and the 6ample container therein
extend6 parallel to the axi6 of rotation of the
centrifuge rotor. However, during roto~ operation the
carrier and the sample container therein pivot6 to an
operational or working position wherein ~he axi~ of
~he ~ample container i6 perpend}cular to ~he ax~ of
rotation of the rotor.
Due to the ext~emely high centrifugal force6
involved in ultracentrifuga~ion, ~generated by rotor
speed~ that are often in exce~s of 50,000 revolution6
12~5S~
per minute), extreme care mu6t be taken ~o provide a
6ecure pivo~al at~achment for ~he carrier as it
~eciprocally piV0~6 between tha initial to the working
po6itions. Typically ~uch pivoting arrangement6 use a
hanger which include~ a hook-like appurtenance formed
(ty~ically integrally) with the carrier. The hanger
engage~ rod-like trunnion~ ~uitably mounted on the
rotor body. ExemplaLy of ~uch pivoting arrangement~
are those 6hown in United States Patent 3,752,390
(Chulay) and United States Patent 4,190,195 ~Chul~y et
al.). United States Patent 4,400,166 (Chulay et al.)
relates to a modified carrier in which the Upp8L end
thereof is provided with a tran~ver~ely extending
opening through which a trunnion ba{ extend6. The bar
i~ received at it6 extremities in vertically disposed
guide ways provided in the body of the rotor.
One of the perceived di~advantage6 with the
pre6ent generation of ultracentrifuge rotor~ of the
~winging bucket type i~ believed to involve the
complexity of the hanger attachment on which ~he
pivotal movement of the carrier occurs. Moreover,
ince thi6 point of attachment i~ the weake~t link the
~winging bucket rotor must be ~ade nece~sarily bulky
in order to provide the requisite 6upport for ~he
carrier6. Thi6 bulk detract6 from the ro~or
performance by increa6in~ acceleration and deceleration
time6~ It al60 mandates increa6ed centrifuge rotor
containment requirement~ and ~educes acce6sibility to
the 6ample containe~.
Accordingly, in vie~ of the foregoing, i~ i~
believed advantag~ou6 ~o provide a swinging bucket
centrifuge ro~o~ which uses the flexible deformation
of the ~aterial of a flexible carrier to ~upport the
~ample containers and accommodate their movement from
a fir~t, re~t, position to the 6econd, operational,
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position which overcome6 the above-di6cu66ed perceived
disadvantages of the prior art.
At the completion of a centrifuge run i~ i6
important that the carrier and ~ample container
supported thereby be restored to it6 initial
orien~ation so that g~adients formed by centrifugation
will not be di6turbed. ~i~h ~his goal in mind i~ i~
believed advantageou6 to provide a rotor cap assembly
o~erative to a~6i6t the return of the flexible ~ample
carrier ~o the initial position.
SUMM~RY OF THE INVENTION
The pre~ent invention relate~ to a centrifuge of
the ~winging bucket-type which, in its broade6t
aspect. compri6e~: a centcal hub connectable to a
source of motive energy; and a flexible sample carrier
connectable to the hub. The carrier has a bendably
deformable region in the vicinity of the periphery of
the hub to permit a 6ample container carried and
6upported by the carrier to move under the application
of centrifugal force from a fir6~, rest, position to a
second, operational, po6ition. The motion of the
sample container i6 accommodated by the flexible
defor~ation of ~he material o~ the sam21e carrier
rathec than by the pivotal motion of rigid member~
with respect to each other. The same material that
deforms to accommodate motion of the container also
accepts the ten6ile load impo6ed on the con~ainer and
the carrier by centrifugal force.
In accoLdance with thi~ invention the sample
carrier i~ fabricated from a plurality of fibers
arranged in a textile structure. The fiberfi are
6uitably inte~connected to form at the radially outer
end of ~he car~ier at lea~t one sling-like ~ocket.
The 60cket may be formed from the fibe~s connected to
~95~Z
themselves with or without the ufie of suitable
"helperl' yarns and/oc rigidization so as to exhibit
adequate strength to resi6t the hydro6~atic pre6sure
developed within the liquid sample by centrifugation.
In thi~ event the 60cket may directly receive the
6ample container. Alternatively, the ~ocket may
receive a vessel able to withstand the centrifugation
pres6ure. The ve6sel i~ sized ~o accept the ~ample
container. In the event that a ~es6el i~ provided a
suitable force transmission arrangement, f or example,
in ~he form of a footing or saddle, may be needed to
transmit ten6ile load~ imposed on the ~ontainer and
the vessel to the flexible carrier.
The fiber~ which form the carrier may be arranged
in any textile structure, e.g., ~trand6, braids, o~
weaves. In addition, the fibers of the carrler may be
arranged in the form twisted or plied structures or
knits. The carrier may be rigidized, as by re~in
impregnation, in the region of it6 attachment to the
hub and/or at the radially outer end6. In the strand
or braided embodiment6 the fibers are arranged 60 as
to diverge from each other ~o define an opening
throuqh which acce6s $o a sample container ~ay be
afforded. In the weave embodiment the fibers are
arranged in a woven stLap which i~ laid back on it~elf
in which access to the sample container may be
obtained from between the p}ies of the strapO
A rotor may be as6embled from a plurality of
sa~ple carriers a~ de6cribed above which are layered
acros6 the hub. Alternately a rotor may be formed
without layering u~ing a flexible cacrier in which the
plurality of 60ckets thereon are flexibly
interconnected to define a central web region which is
~uitably attached to the hub.
1~9S52
In accordance with thi~ invention a cap as6embly
i6 mounted to the ro~or for rotation therewith. The
cap is responsive ~o centrifugal force a6 She rotor
6pins by moving from an initial ~o a final, rai6ed,
po6ition to pe~mit the carrier to move from the first
to the second positions. As the rotor ~lows the cap
responds to gravity to move toward the initial
po6ition. As ~he cap returnfi to the initial po~i~ion
it in~eract6 with the carrisr to assis~ in restoring
the carrier to the first po6ition.
The cap as~embly includes a central di~k with a
skirt depending from the di6k. The skirt has an array
of scallop6 therein. Each 6callop corresponds to a
containe~ carried by the carrier. The height of each
8callop i6 arranged in accordance with the height
above the hub that i6 occupied by the carrier
corre6ponding to the scallop.
A lifting mechanism i~ as~ociated with the cap
a~embly to as~i~e in raising the cap to its final
position. In various embodiment~ the lifting
mechanism u~e~ the ef~ect of centrifugal force on
pivotally mounted cams, entrapped lug6 o~ projecting
~ibbon li~ter6 to raise the cap a~embly. In an
alternate embodimen~ the cap incluaes 6pring aLm~
which are rai6ed in re~po~e to centrifugal force and
which re6iliently act again6t the carrier to re6tore
the 6ame to the fir~t po6ition. If the spring arms
are utilized, the 6kirt is omitted.
BRTEF DESCRIPTION OF THE DRAWINGS
The in~ention ~ill be more fully under6tood from
the following detailed de6cription thereo~ taken in
connection with ~he accompanying drawing~ which ~orm a
part of this application and in which:
g~Z99SS2
Figure 1 i~ a ~ide elevational view entirely in
section of a centrifuge rotor having a layered 6tack
of flexible carrier~ in accordance ~i~h one embodiment
of ~he present inven~ion in which the textile
6tructure of each carrier i5 arranged in ~trands:
Figure 2 i~ a plan YieW ~aken along view lines
2-2 of Figure l;
Figu~es 3 and 4 are views 6imilar to Figures 1
and 2, re6pectively, illustrating a centrifuge ro~or
ha~ing a layered 6tack of ~lexible cacrier6 in
accordance with ~nother embodiment of the ~resent
invention in which the textile structure o~ each
carrier i6 arranged in a braid;
Figures 5 and 6 are view6 6imilac to Figures 3
and 4, re6pectively illu6trating a centeifuge rotor
having a layered ~tack o~ flexible carriers in
accordance with still anoth~r embodiment of ~he
pre6ent invention in which the textile structure of
each carrier i6 again arranged in a braid;
Figure 7 i6 an enlarged view of the arrangement
of ~he braided 6tructure including helper yarn6 which
cooperate to define the 60cket in the carrier ~hown in
Figure6 S and 6;
Figure~ 8 and 9 are views 6i~ilar to Figures 3
ÆS and 4, re6pectively illu~trating a centrifuge rotor
having a layered stack of flexible carriers in
accordance with still another embodiment of the
pre6ent invention in which the textile ~tructure of
each carrier i~ arranged in a weave;
Pigure 10 i~ an enlarged view of the portion of
the woven strap used ~o form the carrier 6hown in
Figure6 8 and 9 in the vicinity of the rotor hub:
Pigure 11 i~ a highIy ~tylized per6pective view
of an al~ernate embodiment of a flexible carrier in
accordance wi~h the pres*nt invention:
~2~315~i~
Figure 12 i~ a side elevational view in 6ection
of a re~toring cap as6embly generally u~ed with a
flexible car~ier (shown in outline) in accordance with
the present invention with the C3p on the left ~ide of
the Figure in the initial position and on ~he right
~ide of ~he Figure in the rai6ed po~ition;
Figure 13 i~ a developed view of the skirt
portion of the restoring cap a~6embly ~hown in Figure
12;
Figure~ 14 and 15 are, respectively, a front and
a side elevational view of the re~toring cap a~sembly
u6ed with a flexible carrier in accordance with the
pre~ent invention with the cap in ~he initial position:
Figure 16 is a plan view taken of the re6toring
15 cap aB8embly taken along ~iew lines }6-16 of Figu~e 14
with portions broken away;
Figure 17 i6 a side 6ectional view of the
re~toring cap as6embly shown in Figures 14 ancl lS with
the sap in the rai6ed po6ition:
Figure 18 is a 6ide elevational view of an
alternate embodiment of the re6toring cap ac6embly
used wi~h a flexible carrier (~hown in outline) in
accordance with the present invention while Figure 19
i6 a plan view thereof with ~ortion6 broken away:
Figure 20 is a side elevational view of yet
another alternate embodimen~ of the restoring cap
a~6embly used with a flexible carrier (shown in
outline) in accordance with the present i~vention
while Figu~e 21 i6 a plan view thereof: and
Yigure 22 i~ a side elevational view of 6till
ano~her embodimen~ of the r46toring cap assembly u6ed
with a flexible carrier ~shown in outline) in
accordance with the present invention and Figure 23 is
a plan view thereof.
~LZ~ii52
DETAILED DESCRIPTIQN OF THE INNENTI~N
Th~oughout the following detailed de6cription,
similaL reference nume~al6 refer to similar -elemen~s
in all figures of the drawings.
A ~winging buc~et cent~ifuge rotor generally
indicated by reference characte~ 10 in accordance with
the the present invention includeE; a ~a~ple ~arrier
generally indicated by ~eference character 38 which,
in its b~oadest aspect. i6 f ormed of fîbers ar~anged
in any predetermined tex~ile structure such that the
carrier bendably deforms to accommodate ~otion from a
first, rest, position ~o a second, ope~a~ional,
po6ition. The rotor 10 described herein is primarily
used in ult~acentrifuge in6truments wherein the
rotational 6peed is in exce~s of 50,000 ~evolution6
~er minute, although it shou}d be understood that its
use i6 not limited exclu~ively thereto and thus may be
used in any centLifuge insteument.
The centrifuge rotor 10 include6 a central hub
generally indicated diagrammatically by refe~ence
characte~ 12 that i6 connectable (as indicated by the
schematic dri~e connection 16) to a suitable source of
motive energy such a~ a drive ~OtOI ~4 for rotation of
the hub 12 about a central vertical axi~ of rota~ion
2~ 12~. As is illustrated in Figure 1 the hub 12
includes a pede6tal 18 having a hollow 20 ~ormed
therein. A ~uitable drive connector (not sho~n) is
~eceived within the hollow 20 to interconnect the
rotor 10 wi~h the drive motor 14. The upper end of
the pedestal lB includes a rece66 22 ~hich i~ ~ized to
receive ~he shank 24 of a substantially disk-like base
member 26. The upper surface 28 of the base member 26
i6 6ubstantially planar (althou~h, a~ developed
herein, it ~ay be g~ooved) and p~ovided with a ~ounded
periphery, a~ shown at 30. The pedestal 18 and the
~z99~
base member 26 are securely interconnected by a pres~
fit and 6ecured wi~h a threaded bolt 32. Rotative
force i6 positively applied through the pede~tal 18 to
the base 26 by mean~ of the pre6s fit and an array of
drive pin~ 3~.
The embodiment of the flexible sample carrier 38
~hown in Figure6 1 and 2 is bendably deformable in the
vicinity ~0 o~ the periphery of the hub 12 to permit a
~ample container 42 carried and 6uppor~ed by the
carrier 38 to move under the application of
centrifugal force from the fir6t, rest, po6i~ion
~hown in the left ~ide of Figure 1) to a ~econd,
operational, position (~hown in the right ~ide of
Figure 1). In the first, rest, po6ition the axi~ 38A
o~ the portion of the car~ier 38 near to the 6ample
container 42 i6 ~ubstantially parallel to the axi6 o~
rotation 12~. In the second, o~erational, po6ition
the axi~ 38A of the carrier 38 near to the sa~le
container 42 i~ 6ub6tantially perpendicular tO the
axi~ 12A. The axi~ 38A of the carrier 3B i6 coilinear
with the axis 42A of the ~ample container 42A. ~he
~ovement of the carLier 38 and the 6ample container 42
carried thereby i~ acco~modated by the flexible
deformation of the material of the carrier 38 rather
than by the pivotal movement of rigid member~ with
re6pect ~o each other. The ~ame ~aterial ~hat deforms
to accommodate mo~ion of the carrier al60 accept~ the
tensile load impo6ed on the ~ample container 42 and
the carrier 38 by centrifugal force.
A6 6een in ~igure6 1 and 2 each ~ample carrier
38 there 6hown i~ an elongated element in which the
f iber~ are arranged in the textile structure o~
6~rand6 46. By "6trand~ it i~ meant any twi6ted,
braided, interlaced, plaited or e66entially parallel
array o~ fiber6 formed i~to a cord. Pref~Iably, but
1299552
not neces~arily, the ~trand6 46 pass 6ubstantially
radially acros~ the hub 12 and are attached at their
midpoint6 to the hub 12. Alternatively, th~ 6trands
may take a partial wrap of any predetermîned angular
di~tance (including sub6tantially 180) about the hub
12. At least one radially outward end of the element
3~ the 6t~and6 46 are interconnected ~o define a
~ling-like ~ocket ~8. The ~trand~ 46 are formed from
a high 6~rength fiber material such as the aramid
fiber manufactured and sold by E. I. du Pont de Nemour6
and Co. under the trademark KEV~AR~. Of course, other
suitable material6 may be used.
As will be developed the socket 48 may be formed
by connecting the strands 46 to ~hemselves either with
or without the use of suitable "helper" yarn6. In
addition, as iB also set forth herein, each 60cket 4B
may be rlgldized, preferably by resin impregnation, to
develop in the 60cket 48 s~fficient 6trength to resi6t
the pre~6ure exerted within the ~aMple by
centrifugation. If the socket 48 can be formed to
exhibit the requisite strength the socket ~ay directly
receive the sample container 42. Alternatively ~he
~ocket 48 accepts a ve66el 50. The vessel 50 i6 a
thin walled element which provide6 a~ imperviou6
member about a liquid ~ample. The axis 50A of the
vessel is collinear to the axis 38A. The u~e of a
ve~#el 50 may mandate the use of a suitable force
tran6mitting element 52 which prefeLably take~ the
f orm of a saddle (Figure6 3 and 4) or a f ooting
(Figure~ 8 and 9~. The tran6mitting element 52 6erve6
to tran6mit loads that are impo6ed on the 6ample
container 42 to the flexible carrie~ 38 80 a~ to
impart a 6ub6tan~ially unifo~m stre~6 to the fiber~ o~
the carrier.
~0
~2~9~i5;~
11
The ~trands are relatively lightly inte~connected
to provide a mo~e con~olidated 6tructure intermediate
hub 12 and the radial end6 of the carrier but not to
the extent where the flexibility of the car~ier i~
impaired. As the ~t~and6 46 pas6 radially inwardly
toward the hub 12 they cooperate to define gap6 58
(Figure 2) through which acce~s i~ afforded to the
~ample container 42.
As alluded to ea~lier the car~ier 3B may be
rigidized, a6 by resin impregnation, in a central
region 60 that lie~ in the viciniey of the hub 12 and
in ~he radial o~ter region6 62. However, tha~ portion
of the carrier 38 inte~mediate the rigidi~ed region~
60 and 62 define~ the flexibly deformable region 40.
This region 40 may be impregnated with a nonrigidizing
matLix that improves to ~urface characteri6tic6
without impairing its flexibi}ity.
To manufacture the ca~rier element 38 shown in
Figures 1 and 2, a 6ingle ~trand of fiber may be
looped about a central mandrel to form one. ~wo or
more 60cke~. The mandrel may become a pe~manent part
of ~he fabricated rotor or may be removed. A collar
having a number of articulating arm~ i6 81ip ~it to
the ~andrel. The arms can be extended and made ~igid
during a winding pha6e and relaxed when the winding is
complete. Each end of each arm may carry an end
member which ~eplicate6 the ~ize and feature~ of a
ve6~el carried in the 60cket. The 6trand is wound
abou~ the mandrel and the number of ~nd~ to form the
desired number of 60cket6. The strand ~hould
uniformly 6urround each end and, therefore, the
winding angle of each ~ass mu6t be slightly varied. A
matrix material or the addition of helper yarnE may be
necea6ary to maintain the position o~ ~he ~t~and. The
6ample carrier may be imp~egnated to define the
rigidized region6 60, 62 discu6sed above.
11
12
In Pigure6 1 and 2 the rotor 10 is 6hown a~
fabricated from a plurality, e.g.. three, sample
carriers 3B-1, 38-2 and 38-3 which are layered over
the hub 12. Of cour~e, any convenient number of
carriers 38 may be received on the hub 12. The
particular number and arrangement of carriers 38
selected will determine the sample capacity (in terms
of container place6) of the rotor 10. The axis of
each carrier 38 is arranged at a predetermined angle A
~Figure 2) with re6pect to the axi6 of the adjacent
carrier. A clamp plate 66 i8 ~ecured to the hub 12,
a~ by bolt~ S8, ~o 6ecure the layered car~ier~ 38 to
the hub L20 The bolt6 68 appear in 6ide eleva~ion
only in Figure 1.
To accommodate the plural layered carrier6 38
the lower ~urface of the clamp plate 66 and/or the
upper 6urface of the ba6e 26 of the hub 12 are
provided with radially extending groove~ 66-1, 66-2
and 66-3. In the Figure6 only the clamp plate 66 i6
grooved. The axi6 of each groove i6 coincident with
the axi~ of one o:f ~he layered carLier~. The depth of
any one of the grooves 66 i6 6U. ficient to accommodate
the carrier received in that groove plu6 the carrier~
layered above it which }ie in other groove6.
Generall~ the de~th of each groove i~ an integer
~ultiple of the height dimension of a ~tacked carrier
taken at the hub. Centering the car~ier6 38 within
the grooves may be provided by adhering at lea~t one
6ide of each carrier to a thin metal plate 70 in the
form of a modified cross that enter6 into at least two
adjacent grsove~. The carrier6 38 may alternatively
be drilled at their center or have a hole formed
therein which allow6;the fiber6 in the carrier to pas~
therearound in a ~treamline fa6hion and a central
6houlder bolt 72 provided through the clam~ plate 66
12
~9~52
13
and into the base 26. (The bolt 72 i6 6hown in
phan~om only in the plan views of Pi~ure6 2, 4, 6 and
9~. The carrier 38 may be held in the correct
posi~ion on the base 26 by mechanical expedient6
(e.g., clamps, pin6 or bolt6), by cemen~ or adhesive
or by EpeCial geometrie~ (e.g., po6itioning plate6 or
groove6 ~ .
In operation, as the rotor 10 i6 spun ~he ~ample
containers 42 carried in the ve~6el6 5Q or directly
received in the 60cket~ 48 move from the fir6t, re6t,
position 6hown on the left side of Figure 1 (in ~hich
the axis 38~ of each sf the carrier6 38 lies
6ub6tantially parallel ~o the ~pin axi6 12A~ to a
second, operational, po~ition (in which the axis 38A
of each of the carrier~ 3B i~ substantially
perpendicular to the 6pin axi6). The motion i~
accommodated by the ~lexing of the nonimpregnated
flexibly de~o~mable region 40 of each carrier 38.
Under deceleration the cever6e motion occur6.
In accordance with another embodiment of the
pre6ent invention carrier 38 i6 arranged in a braided
textile ~tructure. In one a6pect the braided textile
structure i~ defined ~rom a braided cord 76 attached
to both the hub 12 and at least one foree tran6mitting
element 52~ In the prefe~red ca6e the cord i6
provided wieh clo6ed eyelets 78A and 78B at each end
thereof. The eyelet6 78 are preferably fo~med using
an eye-splice in which the end of the cord 76 is
6~1iced back into the cord body to form an eyelet
although any 6uitable technique may be used.
In the preferred in6tance the force tran6mitting
element 52 ~ake6 the form of a hor6e6hoe-6haped ~addle
82. The ~addle 8~ i6 provided with a central bore 84
which receive6 the ves~el 50. A sample container ~ay
be received in the ves6el 50. The exterior surface
13
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14
of each 6addle 76 i~ provided ~ith an array of groove~
8B-l, B~-~. 88-3, and 88-4 to facilitate the wrapping
of the saddles with the cord 7fi. A~ seen in ~igures 3
and 4 two saddle~ 82 are erovided on each c~rrier 38
and are denoted by the characters 82A and 82B
e6pectively, although it i~ to be noted that a
carrier 38 in accordance with thi~ a6pect of ~he
invention may be formed u6ing a single 6addle 82. In
this in6tance both eyelet6 78~, 78B ~urround ~he same
6addle.
One winding pattern that has been found useful
in forming a braided 6tructure f~om a cord 76 having
eyelets 78A and 78B at each end thereof may be
described. The eyelet 7BA i6 provided in the groove
88A-1 o the 6addle 88A. The cord 76 is then wrapped
~equentially around the groove6 88B~ 8A-l and
88B-l. Thereafter the cord 76 i6 wrapped about the
~rooves 08A-2. B8B-2, 88A-2 and ~8~-2. In order to
form a mirror image the cord 76 i8 temporarily
po6itioned (but not permitted to 6eat) in ~he groove
88A-3 and then provi6ionally positioned into the
groove 88B-3. The cord 76 thereafter wrap~ around the
groove 88~-3 underneath the previously depo6ited wrap,
thence to the groove 88B-3 undernea~h the previou~ly
depo~ited wrap. ~he provisionally held wraps are then
6eated. The cord 76 then provi~ionally loop~ the
grooves 88A-4 and 88B-4~ The cord 76 wraps the groove
88A-4 underneath the previou61y depo~ited wrap and
finally to the groove 88B-4 where the eyelet 7BB is
~i~po~ed underneath the previou61y deposited wrap.
The provi~ionally held wraps are then seated. To
equalize leng~h~ the ~addle~ 82A and 8ZB are
06cilla~ed at load6 up to approximately twenty-five
perce~t of the breaking strength of the sy~tem so
formed or a minimum of ten repetition~. The
14
1~9~S52
apertureg 90 (Flgure 4) in each ~addle 62 facilitate
the insertion onto the 06cillating device. The
~tructure may be rigidized by impLegnation -t-o define
the region6 60, 62 therein. Acces~i opening6 58 are
defined. A rotor 10 may be ~ormed of plural layer6 o~
carrier6 38 as di6cussed above.
In the embodiment of Figuce~ 5 and 5 the braided
6tructuce u6ed to form the carrier 3~ i6 defined from
a plurality of cord6 92 (each of which i6 it~elf a
braid in the ~o~t preferred case). The cords 92 are
radially and coaxially di6po6ed in the vicinity of the
hub 12 while the free ends thereof are braided to form
the 60cket 48. The p~eferred mode o~ ~ormin~ ~he
60cket 48 i6 6hown in Figure 7 in which the cords 92
are interlaced by hel~er yarns 94 which pas6 over and
under the cords 92. The free end~ of the helper yarns
94 and the free ends of the cord6 92 are consolidated,
a~ at 96, by any 6uitable expedient, such as
braiding. A}ternately. the fibers which form the
braided cord~ 92 may be u~ed to braid the ~ocket 48,
with the end~ suitably con601idated. In an alternative
~ode, the free end~ of the cords 92 and the helper
yarns 94 ~or the ends of the fiber~ which form the
cord6 92) ~ay be braided back onto themselve~, thus
eli~inating the need for con601idated region 96. If
the ~ocket 48 exhibit~ sufficient ~trength to contain
pres6ure exerted by the li~uid ~ample during
centrifugation the container 42 may be directly
received within the ~ocket 48 (Figures 5 and 6).
Alternatively the ve~sel 50 is erovided within the
60cket 48.
The cacrier 38 i~ rigidized in both the central
and radial outward region~ 60 and 62, respectively.
Rigidizin~ the ou~e~ region 62 a66i~t6 in maintaining
the braid of the socket 48 regardle~ o~ the manner in
which the 60cke~ i6 formed.
l~9~S52
16
The cord6 92 need not extend radially acros6 the
hub 12, but may be bent 180 ~o that each end of each
cord 92 is adjacent. The~e end6 may ~hen be- used to
~orm a carrier 38 wi~h a 6ingle socke~ 48. In thi~
ca6e a ~ubstantial load re~isting attachment must be
provided to the hub. Suitable acces6 openings 58 may
be provided wheLeby acce~6 to the container 42 may be
had while the carrier 38 i6 in the first position.
Carriers 38 may be layered across the hub akin
to the situation discu6sed in connection with Figures
l and 2. The clamping action of the plate 66 in
cooperative as60ciation with the base 26 secures the
carriers 38 to the hub 12 a6 discu66ed above~ In both
braided embodiments the cord 76 or the cord6 92 ~ay be
made ~rom the same material as used for the strand6.
A6 ~een from Figures B and 9 the samp~e carcier
3B arranged in a woven textile structure is defined
from a woven belt or ~trap 102. The strap 102 i~
woven from high strength fiber material ~uch as that
used for the strand~ or the braids. Preferably a
majority of the fiber6 of the belt 102 are arranged
longitudinally, that i~, a~ the warp o~ the weave and
para}lel to the axiç 38A. Thi~ pattern i6 preferred
to enhance the ~rength of the belt 102 in the
direction of it6 expo~ure to maximum load.
The belt 102 i~ overlaid back onto it6elf to
form, in bowtie-like fa~hion, one or more lobe~ 104.
A paie of lobes 104A, 104B, one at each radial end of
the carrier 38, i6 preferred. Preferably the belt 102
i~ overlaid in u~h a manner that a plurality of plies
Qf woven material i~ defined. As seen from Figure lO
~he direction of looping i6 indicated with the
numbered arrows illu~trating the plies in each
direc~ion. Starting ~ith an end lO~ the belt 102 is
; 35 wrapped back on it~elf ~uch that at lea~t ~hree plies
16
~29~552
17
extend in each of two opposed radial directions acro~s
the hub 12. The plies are thus overlapped six deep
acro~s the face of the hub 12. In the vicinity of the
periphe.ry 30 of the hub 12 the plies heading in
opposed directions diverye to define the lobes 104.
The free end 110 of the belt 102 is di~posed eithar
above or below the overlaid plies depending upon the
di~ection of looping. At lea~t 8iX plie6 are
preferred to enhance ~he radial 6~rength w~ile
6imultaneously providing flexibility o~ ~he carrier.
The stacked plies define a height dimension ~16.
~lternately the wovçn carrier 38 may be formed from a
number o~ ne6ted endles6 strap6.
On the interior surface of the radially outer
end6 of each lobe 104 is disposed a force transmitting
member 52 in the form o footing 120. The exterior
6urface 122 of the footing 120 iB configured for clo6e
fitting receipt on the curvlng interior turn o~ the
respective lobe 104 in which the footing 120 i8
dispo6ed. The footing 120 has a pocket 12~ on the
inner sucface the~eof. The vessel 50 having an
enlarged cylindrical ba~e 126 i6 removably receivable
in ~he pocket 124 in the footing 120. The ~ample
container 42 carrying the 6amp}e under te~t may be
received within the ve6sel 50. The ve6sel 50 is
closed by a conical 6~0ppe~ 12~. The ve~el 50 is
movable with re6pect to the footing 120 along the
interface defined between the base 126. The ves6el 50
i~ removable ~idewise of the ca~rie~ 38 via the acce
o~ening 5B defined between plies of the belt 102.
A plurality of carrier~ 38 may be layered, as in
previous instance~, acro~6 the hub 12.
In some instance~ it may be desirable to form a
rotor with a 6ample capacity (in terms of container
place6) that i6 grea~er ~han two ~ithout the necessity
~L~99S~2
18
of layering a plurality of carLier6 38. Thi~ may be
accomplished by a carrier 38' ~hown in Figure 11. In
this e~bodimen~ the fibeI6 defining the individual
~ocket6 48~-1 through 48'-B are interconnected into a
central web region 130 so that the carrier 38' is one
inte~ral textile stIucture. one continuou6 yarn may
be u6ed to form ~he carrier 38' or a number of yarn6
added and 6ub~racted during fabrication to in~ure a
balanced, uniform stres6 pattern thLoughout the
structure. The carrier 38' i~ suitably connected
above or below the surface of the web 130 to the hub
12. The web 130 may be rigidized to define the ~egion
60, as di6cu6sed. The flexible region 40 ~s defined
in the region between the periphery of the hub 12 and
the radiating 60ckets 48. The 60ckets 48 may be
rigidized in the web and at the ends, as discu66ed. A
vessel 5Q may be disposed within each ~ocket 4~
de ired or nece6sary. Each fiocket 48' iB provided
with an acce66 610t 132 by which access to the interior
~o of the socket 48' may be afforded. In opeeation the
movement of each socket 48' from the fir6t, re6t,
po6ition in which its axis 48'~ i6 sub~tantially
parallel to the axi6 of rotation 12A to ~he 6econd,
operaSio~al, position in which the axis 4~'A i6
6ubstantially ~erpendicular to the axis 12A i6
accommodated by the flexible deformation of the carrier
38' in the regions 40'. The carrier 38' i~ formed in
a braided textile structure i~ the preferred case.
--o--O--o--
The stiffnes6 and thickness o~ the flexibly
deformable region 40 i6 6uch that the weight of the
carriers 3~, 38' and/or ve6sel6 and/or sa~ple
containers load ~ay not permit gravity ~o fully
re6~0re the ca~Liers ~com the operational to the rest
~o~ition. Accordingly it may be necessary to p~ovide
1~
~2~95S~
a mechani~m to a~6i~t in re6toring the carriers 38,
38~ to the fir~t, re6t, po6ition. Such a mechanism i~
pro~ided by a re~oring cap a6~embly 140 in accordance
wi~h any embodiment of the pre~ent invention. It
should be under~tood that any embsdiment of the
re6toring cap a6sembly 140 ~hown in Figures 12 thro1lgh
21 may be used with any embodiment of the flexible
carrier 38, 38' previou61y de~cribed 60 long a~
suitable provi~ion i~ made in the cap a~embly 140 to
remove ~he sample from ~he cacrier 38, 38l in which it
i8 6pun. In the Figure~ 12 through 23 the flexible
carrier is shown only in oulline form.
The cap as6embly 140 in the embodiment 6hown in
Figures 12 to 21 includes a substantially in~erted cu~
6haped member formed from an annular disk 142 with a
central collar 144 ha~ing an aperture 145 therein. A
skirt 146 depends from the pe~iphery of the dis~ 142.
The lo~er end of the skirt 146 i8 provided with
diametrical eair6 of scallop~ 148A, 148B and 14BC. as
may be best 6een from the developed view of the skirt
146 shown in Figure 13. U6ing a baseline 150 defined
by a line that ~a6ses through the lowest point on each
6callop 148 a~ a reference, it i6 seen that the
6callop6 148 extend variou6 predetermined height~ 152,
154, 156 above the ba6eline 150. Moreover the high
points of adjacent 6callop6 148 are ~ertically offset,
a~ 6hown ~t 158, 1~0 and 162.
In accordance ~ith this invention the number of
pair6 of scallop~ 148 and ~he number of different
predetermined height6 152, 154 and 156 that ~he
scallop6 extend above the ba6elins 150 corre6ponds to
the number of flexible sample carrier~ 3B u6ed on the
rotor 10. In the in6tance illu6trated i~ Pigure6 12
and 13, if three carrier6 3B are used, three different
di6tances D~152), D2(154) and D3(156) are defined.
~L2~SS~
The 6callop~ 148 having the greate6t height dimen~ion
D3(156) are aligned ~ith the carrier 33-3 that i~ ~he
uppermo~t of the layered carriers while the lea~t
height dimen6ion Dl(152~ i6 radially aligned with the
lowermost carrier 38-1. The 6kict 146 would be
adju~ted to provide an appropriate number of ~callops
148 at the game predetermined height above the
ba~eline 150 to accommodate the ~oc~ets 48' of a
carrier 38'.
~ounted to the upper 6urface of the clamping
plate 66 a6 by an axially extending bolt 168 i~ an
up~anding po~t 170. The clamp plate 66, by vi~tue of
it6 attach~ent to ~he di6k portion 26 by means of the
counter6unk bolt6 68, may be es6entially viewed as a
part of the hub 12. It i6 noted that the bolts 68 are
6hown only in Figure 12 for clarity of illu6tration.
It i8 to be under6tood that the clamp plate 66 shown
in Figure6 14. 15. 16, 18, 20 and 22 i6 attached to
the hub 12 for rota~ion therewith.. The upper end of
the po6t 170 in ~he embodiment of Figure ~2 i6
provided with an enlarged head 172. The po6t 170 i6
dri~en with the clamp plate 66 by an ar~ay of drive
pinB 173. The cap 140 i6 ~lidably received on the
post 170 for movement in the direction of the arrow~
174, 176 ~arallel to the axi6 of rotation 12A.
Relative ro~ation theLebetween i6 prevented by a key
178 that extends radially from the post 170 and engage
into notches 180 provided in the collar 144.
The operation of the cap as6embly 140 may be
unde~tood ~rom Figure 12 in which the left hand side
of the ~igure depic~6 the 6ituation extant with the
sample carrier~ 38, 3~' in the first, re~t, position
while the right 6ide of the Figure depict6 the
6ituation with the6e ele~ents in the second,
opera~isnal, po6i~ion. At rest the radial end6 of the
S52
carrier6 3~, 38' hang o~er the rounded edge 30 o~ the
hub 12 and the cap 140 occupie6 its initial po6ition
in which the undersu~face of the disk 142 lays atop
the upp0~ 6urface of the ~lamp plate 66. ~ the rotor
10 is spun the 6ample container~ are impelled to the
6econd po~ition. This movement is accommodated by the
flexible deformation of the carLier 38, 38' as
di6cu~sad above. A6 it moves ~he carrier 38 abuts the
scallops 148 lifting the cap 140 in the direction 174
(parallel to the axi~ of rotation 12A). The cap 140
thu6 respond~ to centrifugal force to di~place in the
direction 174 to the final, rai~ed, po6ition. The cap
140 remain6 elevated at it6 rai6ed po6ition while the
rotor 10 iB at operating 6peed. The upward movement
of the cap 140 i6 li~ited by abutment between the
annular shoulder 144S on the ~ollar and the ~urface
172S on the under6ide of the enlarged head 172.
A8 the rotor L0 610w6 the cap 140 begin6 to move
in the direction 176. The weight of the cap 140 is
impre~6ed upon the ca~riers 38, 3B' a~ the cap 140
re6pond~ to gravity thereby a6sigting the return of
~he carrier~ 38, 38~ and the container6 carried
thereby to the fir6t po~ition.
In 60me in6t~nce6 it may be de~irable to provide
a lifting mechani m to a66i~t in li~ting the cap 140
to the ~aised po6ition. The embodimen~ o~ the
invention shown in Figure~ 14 through 21 include 6uch
a lifting mechani6m.
In the embodiment of the invention ~ho~n in
Figures 14 through 17 the po6t 170' ha6 a hollow
interior region as indicated at 172 and ha6
diametrically oppo6ed slots 180A, 180B (Figure 17)
which extend ~ubstantially along the length hereof.
The collar 144 i6 61idably recei~ed on the ~ost 17Q'
for relative motion in the direction6 174, 176
21
~9SiS2
22
parallel to ~he axi~ of ro~ation 12A. The lower end
of the po~t 170~ is provided with an snlarged base 182
whereby the po~t 170~ ~ay be secured to the clamp
plate 66 by an array of bolt~ 16~. The under6ide of
the di6k 14Z i6 rece~6ed, a6 at 184 ~Figure 17), to
accommodate the head6 of the bolt6 168'. The collar
144 i6 provided with regi~tered openings 186A, 186B
which regi6ter with the slot6 lBOA, 180B, re~pectively.
The upper end of the po6t 173' i6 threaded to
lo receive a guide holde~ l90 which i~ 6ecured
nonro~ationally to ~he po~t 170' by 6et screw6 19Z
~Pigure 15). A pair of ~tepped 6eat6 194 are formed
within the upper po~ti~n of the guide holder l90.
Each ~eat 194 receives a guide member 196. The guide~
196 are each provided with a groove 198 which, when
registered, define an ax~ally extending channel 200
which communicate6 with the hollow interior 172 of the
post 170'. The groove~ 198 continue over the u~per
surface of the guides 196 and radially regi6ter with
notche6 202 pro~ided in diametrically oppo6ed relation
in the guide holder 190. The rim6 of the notche6 202
are rounded, a6 at 204. A cover ~late 206 is 6ui~ably
~ecured to the upper surface of ~he guide holder 190
by bolt6 208.
A pair of elongated ribbons 216A and 216B e~tend
through the hollow interior 172 of the po6t 170',
through ~he channel 200 defined between the
con~ronting guide6 196, and cadially ou~wardly of the
holder 190 th~ough the groove~ 19B and notche6 202.
~he lowe~ end of each ribbo~ is enlarged, a6 at 218
(Figure ~5), and i provided with an eye opening 220.
The cap a~6embly 1~0 i~ pinned to the ~ibbon~ 216 ~y a
radially extendi~g pin 224 which extends through one
o~ the opening6 186A in the collar 144, in~o the po~t
: 35 170' through the 610t 180~ cor~e6ponding to the one
. 23
o~ening 136A, through the regi6tered eyes 220 at the
lower end~ of the ribbon~ 216, an~ then ~hrough ~he
other of the ~lot~ 180B and the opening 1~6A. Spacer6
230 stand the pin 224 off the inner 6urace of the
5 po6t 170~. The ribbon~ 216 are formed of a 6uitably
den~e material, as chrome steel, and configured to
exert a predetermined lif~ing force on the cap
assembly 140 deriYed in a manner to be discug~ed.
In operation, in the initial po6ition, be~t
~hown in Figure~ 14 and 15, the under~urface of the
di6k 142 abut~ the ba6e 1a2 of the po~ 170'. A
predetermined length 234 (Pigure 1~) o~ the upper end
of the ribbon6 216 extend6 radially outwardly of the
guide holder 190. A6 the cotor rotate6 centrifugal
force act6 on the radially projecting portion6 234 of
the ribbon~ 216 drawing the ribbons radia}ly outwardly
in the direction of the arrows 236. Concomitantly,
the radial outward motion of the ribbons 216 lifts the
cap as~e~bly 140 in the upward direction 174 via the
interconnection of the lower end~ of the ribbons 216
to the collar 144 of the cap 1~0 through the pin 22~.
Thu6 a6 the rotor ~pins and the flexible carrier~ 38,
38' move a& earlier di~cussed the ribbon6 216
coopera~e to lift ~he cap 140 from the initial
po6ition to the final, rai~ed, eosi~ion ~6hown in
Figure 17). The action of the carrier 38, 38' again6t
the 6kirt 146 as6i~t6 in lifting the cap 140. Upward
~otion of the cap a~6embly 140 i~ arre6ted by the
abutment between the upper 6urface 144S of the collar
144 ~ith the annular under6houlder l9CS of the guide
holder 190.
A6 the rotor ~low~ the cap a~sembly 140 is
lowered in counter direction 176 a6 the weight of the
cap 140 overbalance6 the lifting force generated by
the action of centrifugal force on the ribbon6 216.
~2995~
24
The re~toring action of the 6kirt 146 on the carrier6
40 uLges the return of the ca~rier~ 38, 38' from the
~econd to the fi~t po&ition.
In the embodiment of the cap 140 ~hown in
Figure~ 18 and 19 the po~t 170 i6 modified to ~rovide
longitudinally extending 610t~ 23~ along a portion
thereof. Pivotally mounted in the 610t6 238 are pivot
element6 240. The elements 240 aLe mounted on pins
242 received in bore6 Z44 formed in ~he portion of the
po6t 170 defining the ~Iot6 238. The inner ~urface of
the core 142 i6 provided with cam follower surface 246.
In operation, while in the initial position
6hown in the left 6ide of Figure 18 the pivot element~
240 hang in a retracted po6ition within the 610t6
lS 238. A~ the rotor 10 6pins centrifugal force urge6
the pivot element6 240 radially outwardly into contact
with the cam surfaces 242. This action lift~ the cap
140 along the post 170 in the upward direction of the
a~row 174. A6 the rotor 610ws the weight of the cap
140 become6 do~inant, urging the car~ier6 38, 38' to
the fir6t po~ition. ~ny predetermined number of pivot
element6 240 and corre6ponding ~urface6 242 may be
used .
With reference to Figure6 20 and 21 shown i8
6till another alternate embodiment of the cap a6sembly
140 embodying the teaching6 of the present invention.
In thi~ embodiment the disk L42 i6 provided with a
tapering central member 248 having an array of
radially outwardly extending arms 252. The di6k 14~
i~ ~lidable in the direction 17~, 176 along a guide
: bolt 253 threaded to the clamp plate 66.
In this embodiment, at~ached to the upper
6urface of the clamping plate 66 by an array of bolt
168" i~ a central coLe 254. The cent~al core 254
include~ an array of gene~ally upwardly and outwardly
24
~2~95S2
inclined trackway~ 256. An array of radially
extending ~lot6 260 i6 provided in the member 254 with
each slot 260 interrupeing each ~rackway 256.- Trapped
within each trackway 256 i8 a liftin~ lug 262. In the
a66embled 6tate the arm~ 252 of the central portion
248 are rece;ved within the ~10~6 260 ~uch that the
arms 252 pa~s through each trackway 256.
In operation, with the rotor 10 at the re6t as
6een in the left ~ide of Figure 20 the lugs 262 repo6e
lower ends of the trackway6 256 with the lower edges
Qf the arms 252 re6~ing above the lug6 262. A~ the
ro~or 10 i6 ~pun the lug~ 262 are urged by centrifugal
force to move within the trackways 256 in the
direction of the arrows 266. The lug6 262 abut
against the arm6 252 which pas6 through the track~ay
256. As the lug6 262 move in the trackway 256 they
act again6t the acm6 252 li~ting the 6ame in the
direction 174 alonq the guide bolt 253. The upward
motion of the di6k 142 i6 limited by abutment with the
~houlder 142S on the di6k with the enlarged ~ead 253H
of the bolt 253, a6 6een in the right ~ide of Figure
20. A6 the rotor slow6, the lug~ 262 fall back into
the lowest extremity o the trackway 256, with the
arm6 252 following suit in the direction 176 to lower
the skirt 146.
Shown in Figure6 22 and 23 are 6ide 6ectional
and plan views 6howing an alternate embodiment of a
cap a~6embly 140' of the pre6ent invention. In thi6
embodiment the cap a~6embly 140' includes a di6k 272
to which is appended an array of 6pring arm6 274. The
di~k 272 and the arm6 274 are ~ecured to the plate 66
by the bolt6 276. The number of 6pring arm6 27~
correspond~ ~o the number of ~ample container6 40
~upported in the socket6 48, 48' of the carrier6 38,
3~ on the rotor 10. The arm6 Z74 are fabricated from
~2~552
26
any 6uitable material, 6uch a~ chroma-vanadium
6pringsteel.
In operation, as the rotor 10 i6 . 6pun the
centrifugal force effect~ on the flee end6 of the
s 6pring arms 274 cau6es them to lift upwardly and
outwardly in the direction of arrow~ 278 until the
carrier6 38, 38~ and the arm~ 274 occupy the po~ition
shown in the right 6ide of Figure 22. In this
po6ition the end6 of the arm6 274 lie above the ends
lo of carriers 38, 38'. A6 the rotor 610w6 the
resiliency of ~he ~pring arms 274 again becomes
dominant, urging ~he carriers 38, 38' in the direction
280 to the first po~ition.
Those skilled in the art may appreciate that in
view of the preferred embodiment of the invention as
above described numerou~ modification6 thereto may be
effected. However the6e modi~ication6 are to be
construed a6 lying within the scope of the pre6ent
invention, ~fi s2t forth in the appended claims.
