U.S. patent number 3,674,197 [Application Number 05/070,273] was granted by the patent office on 1972-07-04 for washing means for flexible bags in split enclosures.
This patent grant is currently assigned to Ivan Sorvall, Inc.. Invention is credited to David F. Mitchell, William A. Romanauskas.
United States Patent |
3,674,197 |
Mitchell , et al. |
July 4, 1972 |
WASHING MEANS FOR FLEXIBLE BAGS IN SPLIT ENCLOSURES
Abstract
Improved enclosure for supporting flexible bags within a
centrifuge rotor for washing biological particles in a closed
system. Each collapsible bag is enclosed and supported by a
juxtaposed pair of half-shells forming a unitary cavity or chamber
to which the filled bag conforms during centrifugation. The
enclosure serves to prevent undue wear and stress upon the rotor
receptacle and, at the same time, safeguards the integrity of the
flexible bag during centrifugation.
Inventors: |
Mitchell; David F. (Trumbull,
CT), Romanauskas; William A. (Southbury, CT) |
Assignee: |
Ivan Sorvall, Inc. (Newton,
CT)
|
Family
ID: |
22094271 |
Appl.
No.: |
05/070,273 |
Filed: |
September 8, 1970 |
Current U.S.
Class: |
494/17; 494/29;
494/21 |
Current CPC
Class: |
B04B
5/0428 (20130101); B04B 5/0442 (20130101); B04B
2005/0435 (20130101) |
Current International
Class: |
B04B
5/00 (20060101); B04B 5/04 (20060101); B04b
015/02 () |
Field of
Search: |
;128/214R,214A
;233/26,1R,19R,19A,14R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Franklin; Jordan
Assistant Examiner: Krizmanich; George H.
Claims
We claim:
1. A centrifuge apparatus comprising a rotor, a plurality of
separate spaced cups in said rotor, a collapsible cylindrical bag
for each of said cups, a pair of shells for each of said bags, a
semi-cylindrical cavity in each of said shells, said shells when
juxtaposed forming a unitary cylindrical cavity within which a
respective bag fits and is entirely confined, the assembly of said
pair of shells and said bag being removably inserted longitudinally
into a corresponding rotor cup, the seam between said shells being
arrayed substantially parallel to the longitudinal axis of said
cup.
2. Apparatus according to claim 1 and further comprising means
integrally formed on said pair of shells at the top and bottom of
said cavities for confining the respective top and bottom of said
bag.
3. Apparatus according to claim 1 and further comprising inlet
means and outlet means at the top of said bag and corresponding
mating recesses in each of said shells through which said
respective inlet means and outlet means extend.
4. Apparatus according to claim 1 wherein the juxtaposition of said
shells forms a diametrical seam, said seam being arrayed radially
in said cup relative to the axial center of the rotor.
5. Apparatus according to claim 1 and further comprising
cooperating means on each of said cups registering with each other
to locate said cups in relation to each other to form a smooth,
unitary symmetrical cylindrical cavity therebetween.
6. Apparatus according to claim 1 wherein the bottom of each shell
has a semi-conical shape bounding the semi-cylindrical cavity, and
further comprising integrally formed ribs extending downwardly from
each shell, the bottom surfaces of said ribs conforming
substantially to the bottom of the rotor cup.
7. Apparatus according to claim 6 wherein said ribs are radially
arrayed and form a star-shaped support for said juxtaposed shells
within said rotor cup.
8. Apparatus according to claim 1 and further comprising a
longitudinally arrayed flat on the outer surface of each shell
intermediate the longitudinal edges thereof, said flat permitting
venting of air when the assembly of said shells is moved into and
out of the respective rotor cup.
9. Apparatus according to claim 1 and further comprising inlet
means and outlet means at the top of said bag, and first and second
mating recesses in each of said shells through which said inlet
means and outlet means, respectively, extend, said outlet means and
said second mating recesses being located in the axial center of
said respective bag and of said mated shells, and said first mating
recesses and said bag inlet means being located off-center from
said outlet means.
10. Apparatus according to claim 9 wherein said inlet means and
said first mating recesses are spaced further apart from the axial
center of said rotor than said outlet means and said second mating
recesses.
11. Apparatus according to claim 1 and further comprising spaced
apart inlet means and outlet means at the top of said bag and
corresponding mating recesses in each of said shells through which
said respective inlet means and outlet means extend, said inlet
means being located radially further than said outlet means from
the axial center of said rotor, said inlet means extending into the
interior of said bag and terminating at a position below said
outlet means in said bag and radially a greater distance from the
axial center of said rotor than said outlet means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a novel apparatus for centrifuging and
washing biological particles and the like, and more particularly to
a separable enclosure for supporting a flexible bag through which
the washing and centrifugation process takes place when said bag is
confined in the cup or receptacle of a spinning centrifuge
rotor.
2. Description of the Prior Art
When soft, flexible bags are inserted into respective cups of a
centrifuge rotor, there is encountered the problem of properly
supporting each of the liquid filled bags as they are continuously
rotating. The bags are subjected to various pressures and forces
during centrifugation whereby they are not evenly distributed
within their respective cups of the rotor. Thus, shifting of
position or other movement of the bags relative to the walls and
bottom of their respective cups causes wrinkles and folds in the
bag material with the consequent imbalancing of the rotor due to
the resulting change in volume. Furthermore, these disadvantages
are aggravated when there is no element on top of the bag to
maintain it in position in its respective cup during the spinning
of the rotor and to prevent undue expansion of the flexible bag
which would otherwise cause the top of the bag to extend above the
top of its cup thereby interfering with the centrifuging process,
or causing the bag to rupture.
Some attempt has been made to overcome these disadvantages by
providing a removable shaped support element on the bottom of the
rotor cup which accommodates the shaped bottom contour of the
centrifuge bag while, at the same time, a removable weight element
is placed on top of the flexible bag within each cup to prevent the
bag from being dislodged during centrifugation from its cup. The
drawback of the bottom shaped support element is that the apex
thereof frequently produces a highly stressed area upon the bottom
of the rotor cup during high speed centrifugation. As for the
weight element that is superimposed on top of the flexible bag,
said weight, if not of sufficient mass, can be pushed upwards and
out of the rotor cup during the filling of the bag which, being
flexible, is capable of expansion. Said weight appreciably adds to
the total force exerted on the rotor thereby decreasing the usable
volume or operating speed of the rotor. Placement of the soft
flexible bag within the rotor recess without folds or wrinkles
requires considerable care on the part of the operator, who is then
faced with the task of properly positioning the top weights before
this portion of the operation is complete.
Continuous washing centrifugation of particles in a closed system
utilizing flexible bags is disclosed in United States Pat. Nos.
3,347,454 and 3,211,368.
SUMMARY OF THE INVENTION
The disadvantages and drawbacks of the prior art have been overcome
by applicants' novel invention wherein the flexible bags are
completely enclosed in paired half-shell elements which not only
support the bag within the rotor cup or receptacle, but also
provide for distributing the weight of the bag over substantially
the whole area of the floor of the receptacle. At the same time,
undue expansion of the flexible bag at the top thereof is also
prevented by the single enclosure which is also appropriately
formed to accommodate the inlet and outlet tubes communicating with
the flexible bag in the interior of each enclosure. Furthermore, by
providing the flexible wash bag with a strong but lightweight
enclosure which ensures the confinement of the bag within its rotor
cup, considerably higher speeds of centrifugation can be achieved
than those possible with prior art arrangements. Insertion of the
bag in one-half section and placement of the other half over this
combination results in a firm, rigid, easily handled assembly that
can be readily inserted into or removed from the rotor body.
These and other novel features and advantages of the present
invention will be described and defined in the following
specification and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the container assembly of a pair of
half shells in the unitary cavity of which is lodged the flexible
centrifuge bag;
FIG. 2 is an exploded view in somewhat reduced size of the device
in FIG. 1 showing the internal cavities of the respective half
shells and the blood washing bag that fits into the combined
cavities thereof;
FIG. 3 is a schematic vertical section view of a centrifuge rotor
and enclosure illustrating the manner in which pairs of half-shell
enclosures are inserted into respective rotor cups and showing the
fluid transfer means for transmitting washing liquids continuously
through the washing bags located within half shell enclosures;
FIG. 4 is an enlarged view taken on line 4--4 of FIG. 3;
FIG. 5 is a further enlarged exploded elevation view of the half
shell elements shown in FIG. 2, with a section view of the washing
bag shown located in the cavity of one of said half shells;
FIG. 6 is a somewhat reduced view taken on line 6--6 of FIG. 5;
and
FIG. 7 is a bottom view of the combined half shells in a size
comparable to that shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail, the apparatus of the
present invention comprises a pair of semi-circular half shells,
generally designated 11 and 12, respectively, injection molded or
otherwise formed of a suitable inert thermosetting or thermoplastic
material such as Noryl, a thermoplastic material with or without
fiberglas filler, made by General Electric Co., or other suitable
material. Shells 11 and 12 are substantially identical structurally
except for several portions thereof which will be described
hereinafter.
Each shell 11 and 12 has a semi-cylindrical cavity 13 and 14,
respectively, the lower portions of which terminate in half conical
cavities 16 and 17, respectively. Cavities 13 and 14 are bounded on
their vertical sides by ribs 18 and 19, respectively, while
semi-conical cavities 16 and 17 are bounded by ribs 21 and 22,
respectively.
The top portions of cavities 13 and 14 are bounded by semi-conical
shoulders 23 and 24, respectively, which in turn are bounded by
ribs 26 and 27, respectively. Ribs 21 and 26 are each provided with
a pair of integrally molded, spaced apart pins 28, while ribs 22
and 27 are each provided with integrally molded spaced apart
recesses 29. Said pins 28 and said recesses 29 cooperate with each
other to align shells 11 and 12 in respect of each other to form a
unitary symmetrical cylindrical cavity composed of the combination
of cavities 13, 16, and shoulder 23, with corresponding cavities
14, 17 and shoulder 24, while ribs 18, 21 and 26 mate with
corresponding respective ribs 19, 22 and 27.
Formed in the top of shells 11 and 12 are semi-circular conical
collars 31 and 32, respectively. Communicating between cavity 23
and collar 31 is an axially positioned semi-cylindrical aperture
33, and communicating between cavity 24 and collar 32 is an axially
positioned semi-cylindrical aperture 34. Laterally spaced apart
from aperture 33 to the left (FIG. 2) in shell 11 is a longitudinal
semi-cylindrical aperture 36 which establishes communication
between cavity 23 and through collar 31, while laterally spaced
apart from aperture 34 to the right in shell 12 is a longitudinal
semi-cylindrical aperture 37 which establishes communication
between cavity 24 and through collar 32. When shells 11 and 12 are
juxtaposed, apertures 33, 34 and apertures 36, 37 are aligned with
each other to form respective unitary passageways whose function
will be described hereinafter.
In the region of apertures 36 and 37, collars 31 and 32 are formed
in semi-conical contours 38 and 39, respectively, so that when said
contours are juxtaposed and aligned with each other they form a
unitary supporting surface for flexible tubing passing therethrough
whereby kinking and pinching of said tubing are obviated during
centrifugation and whereby full liquid flow will be maintained
through said tubing during that operation.
Ribs 21 and 22 extend downwardly from respective recesses 16 and 17
and when juxtaposed, together form a unitary diagonal rib, the
bottom of which is contoured to conform substantially to the bottom
surface of a receptacle in a centrifuge rotor. Shells 11 and 12 are
also provided at the bottom thereof with integrally formed
identical ribs 41 and 42, respectively, (FIG. 7) extending
perpendicularly relative to ribs 21 and 22 and whose thickness and
shape are substantially identical with that of combined juxtaposed
ribs 21 and 22. The bottom contour of the combination of ribs 41
and 42 is identical with the bottom contour of ribs 21 and 22 for
resting upon the bottom of the rotor receptacle, thereby forming a
radiating star or cruciform support for shells 11 and 12 within
said rotor. It is contemplated that in some embodiments additional
ribs may be formed at the bottom of shells 11 and 12 to form
symmetrical star arrays for supporting the assembly of said shells
in the receptacle of a centrifuge rotor.
While ribs 26 and 27 form a diagonal support structure between
collars 31 and 32 on the one hand, and shoulders 23 and 24 on the
other, there is further provided in shells 11 and 12 vertical ribs
43 and 44, respectively, which are arrayed perpendicularly relative
to ribs 26 and 27. When said shells are juxtaposed, ribs 26, 27 and
43, 44 form a radiating star or cruciform support structure between
shoulders 23 and 24 on the one hand, and collars 31 and 32 on the
other. See FIG. 6. In some embodiments, additional ribs in
symmetrical array may be formed in shells 11 and 12 in star array
to form a support structure between said shoulders and said
collars. In the areas of semi-cylindrical apertures 33, 34 and 36,
37, ribs 26, 27 and 43, 44 are somewhat enlarged for reinforcement
purposes.
Formed on the outer surface of shells 11 and 12 substantially at
the apex thereof are respective longitudinal flats 46 and 47 which
serve to permit venting of air from the rotor receptacle when the
combined shells are inserted therein and which permit ready
withdrawal whereby vacuum effects are obviated within said
receptacle.
The unitary cavity formed by semi-circular cavities 13, 14 and 16,
17 and 23, 24, when shells 11 and 12 are juxtaposed as in FIG. 1,
is intended to be occupied by a soft, flexible, and collapsible
blood washing bag 48 or the like made of a flexible plastic
material, said bag having a principal cylindrical portion fitting
into combined cavities 13 and 14, an integrally formed conical
portion 49 at the bottom thereof fitting into combined cavities 16
and 17, and an integrally formed conical top 51 fitting against
combined shoulders 23 and 24.
The size and shape of bag 48 is arranged to conform substantially
to the contours of the cavities of juxtaposed shells 11 and 12 when
said bag is filled with materials that are being centrifuged and
washed therein. At the same time, the juxtaposed shells, when
confined in a rotor receptacle, are intended to maintain the
contour of said bag and to prevent the latter from expanding.
The top 51 of bag 48 has a pair of upwardly extending integrally
formed spaced apart tubes 52 and 53. Outlet tube 52 is located
axially of bag 48 and is extendable through the central aperture
formed by combined semi-cylindrical apertures 33 and 34 in shells
11 and 12, respectively. Inlet tube 53, which is located off-center
from tube 52, is extendable through the aperture formed by the
combined semi-cylindrical apertures 36 and 37. Connected with a
liquid-tight seal to tube 52 is one end of a flexible outlet
connecting tube 54, and connected with a liquid-tight seal to tube
53 is a flexible inlet connecting tube 56.
Inlet connecting tube 56 extends through tube 53 and enters into
bag 48 and terminates approximately at the downwardly extending
apex of conical portion 49 of bag 48. In other embodiments, inlet
connecting tube 56 may terminate at any suitable location
intermediate the top and bottom of bag 48, but in all cases the end
of said tube will be located at a point farther from the axial
center of rotor 58 than that of the juncture of outlet tube 52 with
the upper portion of said bag.
The assembly of bag 48 and shells 11 and 12, as shown in FIG. 1, is
insertable into a suitable cup or receptacle 57 of a centrifuge
rotor 58 (FIG. 3) mounted on and rotated by drive shaft 59
connected to a rotating power source such as an electric motor,
turbine drive, or the like, not shown. The assembly of juxtaposed
shells 11 and 12 forms a close sliding fit with the interior wall
of rotor cup 57. Rotor 58 spins within a protective centrifuge
enclosure 60. As shown in the drawings, and particularly in FIG. 3,
a pair of shells 11 and 12 is removably insertable longitudinally
into a corresponding rotor cup 57 with the juxtaposed edges of said
shells forming a seam arrayed substantially parallel to the
longitudinal axis of said cup.
The diametrical seam 61 between each pair of juxtaposed shells 11
and 12 (FIGS. 6 and 7) is arrayed radially from the axial center of
rotor 58 whereby inlet tube 53 of bag 48 is located further from
said center than outlet tube 52 while both of said tubes are
radially aligned in respect of each other. The requirement for
locating inlet tube 56 at a distance further than the outlet tube
52 from the axial center of the rotor is well known in the art.
Moreover, the provision in the juxtaposed shells of the spaced
apart apertures through which respective inlet and outlet tubes 53
and 52 extend, helps to ensure that bag 48 will remain in a
stabilized position within said shells and will not shift within
the rotor receptacle during centrifugation as experienced in
previous biological and blood cell washing apparatus.
Customarily, the biological cell or blood washing system consists
of a pair of identical washing bags 48 that are positioned within
respective rotor cups 57 which are located 180.degree. apart from
each other, as shown in FIG. 3, so as to provide desirable symmetry
of weight distribution in rotor 58. The respective inlet and outlet
connecting tubes 54 and 56 of the pair of bags 48 are connected to
a rotary seal 62 which schematically represents any one of a number
of rotary seals that are known in the art. Rotary seal 62 is
connected to a stationary shaft 63 through which inlet supply and
outlet effluent tubes 64 and 66, respectively, are connected. By
means well known in the art, rotary seal 62 establishes
communication between inlet supply tube 64 and connecting and inlet
tubes 56 and 53 of bags 48, and also establishes communication
between outlet effluent tube 66 and connecting and outlet tubes 54
and 52 of bags 48. The exact pathways of communication through
rotary seal 62 between tubes 64 and 66 and between tubes 54 and 66
are not within the purview of the present invention and are within
the province of those skilled in the art.
In operation, inlet supply tube 64 is connected to a suitable
reservoir, not shown, which contains, for example, a supply of
blood mixed with a suitable washing material, said blood mixture
being transmitted under pressure through inlet tube 64 and
simultaneously through connecting tubes 56 into bags 48 while rotor
58 is spinning. Alternatively, whole blood is initially introduced
through tube 64 and tubes 56 into bags 48, after which washing
fluid is introduced through tubes 64 and 56 to wash the cells
within bags 48, said cells remaining within said bags while the
less dense washing liquid effluents and blood serum emerges from
bags 48 through connecting tubes 54 and thence through outlet tube
66 into a suitable receiver, not shown. After the biological cells
or blood cells have been adequately washed as may be determined
empirically by the nature of the effluents received from outlet
tube 66 or by other suitable means, the centrifuging process is
terminated, after which bags 48 and their respective paired shells
11 and 12 are removed from cups 57. Shells 11 and 12 are readily
separated to free bag 48 which is then cut open or otherwise
emptied and the washed cells are transferred to a suitable
container for further clinical or biological analysis and research
study.
It is understood that the shape of the unitary cylindrical cavity
formed by the juxtaposed shells 11 and 12 will conform
substantially to the shape of the flexible bag located therein so
that when said bag is filled with materials being centrifuged, it
will substantially fill said unitary cavity and, at the same time,
will be prevented from expanding more than any desired amount by
virtue of its confinement within said shells.
By providing ribs 21, 22, 41, 42, 26, 27, 43 and 44, in the
respective bottom and top locations of shells 11 and 12, the weight
of said shells is reduced to a minimum without sacrifice of
structural strength when undergoing the stresses of
centrifugation.
Although the present invention has been described with reference to
particular embodiments and examples, it will be apparent to those
skilled in the art that variations and modifications can be
substituted therefor without departing from the principles and true
spirit of the invention. The "Abstract" given above is for the
convenience of technical searchers and is not to be used for
interpreting the scope of the invention or claims.
* * * * *