Note: Descriptions are shown in the official language in which they were submitted.
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Description
RE~YDRATOR
Field of the Invention
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The present invention is directed to a rehydra~or or
microdispenser wherein a plurality of syringe type devices
can simultaneously pickup predetermined quantities of
fluid from a trough and dispense the same into a plurality
of individual receptacles.
Prior Art
The patent to Sekine 4 ~ 047 ~ 438 is directed to a liquid
quantitative dispensing apparatus comprised of a plurality
of pipettes arranged in rows in a first plate member. A
flexible sheet of rubber or the like having a plurality
of cap-like pro~ections is disposed on the plate with
each cap-like projection being disposed over the open
upper end of a pipette. A plurality of plungers on
a second plate are guided for vertical movement into and
out of engagement with the cap-like projections to control
the air within the cap-like projectlons to withdraw fluid
from a reseirvoir into the pipettes and to subsequently
dispense the liquid into a plurality of wells which are
moveable under the pipettes.
The patent to Byrd 3,982,438 is directed to a multiple
sample pipetting appa-atus which operates on the same
principle as Sekine patent with the exception that the
positive air pressure is used to control deflection of
a diaphragm to control the air within the individual
pipettes which in turn ~will control the picking up and
dispensing of fluid.
The patent to Marc;elli 4~1G6s911 is directed to a
device for dispensing a plurality of ~icro-doses of a ~
1iquid. A plurality of sy~ringes are mounted on a f1xed
support and the plungers are all secured to a plate which
ls mounted for vertical rèciprocating moveme~t by means
of a motor operating through a~screw and nut arrangemen~.
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A support is also mounted for ~rertical movement below the
syringes for supporting various trays having either a
reservoir or a plurality of receptlcles. The plungers
of each syringe are slidably mounted within the body and
are provided with a r:lng of sealing material ad~acent the
end thereof to provide a slidable airtight connection
between the plunger and the body of the syringe.
The patent to Lancaster 3,568,735 is directed to a
laboratory dispensing apparatus wherein a common diaphragm
overlies a plurality of pistons which are reciprocable
within chambers formed in a plate. The pistons are
provided with a rod which is slidably disposed in a
barrel to control the ~ickup and dispensing of fluid.
The patent to Zanasi 4,116,247 is directed to a dosing
lS device which is comprised of a tubular housing which is
vertically moveable up and clown. A hollow punch is
secured to the lower end of the housing and a piston is
slidably disposed within the hollow punch for reciprocating
movement. The piston rod~ is secured at its upper end to
an actuating rod by means of a magnetic connection. In
operation, the hollow punch is inserted into a supply of
powered material all the~way to the bottom of the container
holding the powered material. ~Depression of the piston
will then compact the powered material within the punch.
The punch may then be withdrawn and upon further movement
of the piston in the same direction, the plug of compacted
powdered material will be ejected.
Summary of the Invention
The present invention provides a new and improved
rehydrator which is inexpensive in construction, easy to
use and extremely accurate in operation. ~ -~
The present invention is directed to a new and improved
rehydrator comprised of a plurali~y of syringe-like devices
having the barrel portlons thereof secured ~o a first
plate and the plungers thereof secured to a second plate.
Due to the loose fi.ting sliding engagement of the piungers
within the barrels, cIose tolerances nee2 not be ma~lntained
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in locating the barrels, close tolerances need not be
maintained Ln locating the barrels and plungers on their
respectlve plates, thereby simplifying and expediting the
construction of the rehydrator.
The present invention provides a new and i~proved
rehydrator comprising a plurality of hollow barrels
secured in apertures in a first plate and extending
perpendicular thereto from the underside of the plate.
A plurality of solid plun~ers are secured to a second
plate disposed parallel to the f iro.t plate with the
plungers slidably disposed within the hollow barrels.
The second plate is guided for reciprocating move~ent
toward and away from the first plate and spring means
are provided for normally biasing the second plate away
from the first plate to withdraw the plungers within
the barrels. The plungers have sufficient length so that
upon moving ~the second plate into contact with the first
plate, the plungers will protrude beyond the ends of the
barrels so that upon insertion of the ends of the barrels
and plungers into a fluid reservoir with the piungers
protru~cing beyond the ends~of the barrels, the surface
tension of the fluid will be broken and the ends of~the
barrels will be wett~ed. up~Gn withdrawal of the
plungers into the barrels, a predetermined amount of
fluid will be drawn up into the ends of the barrels.
Upo~n positioning of the assembly over a tray having a
plurality of individual wells or receptacles, the second
plate can be moved toward the first plate thereby extending
the ends of the plungers beyond the ends of the barrels
to dispense the fluid contained in the barrels into
respective ~ells or receptacles. Suitable frame means
may ~e provided for spacing the first plate the correct
distance above the fluid reservoir and the tray having
the individual receptacles to ensure the proper operation
of the rehydrator.; Actuator means may~also be secured
to the frame~means for moving the second plate toward
and away from the f~irst plate. ~The forgoing and other
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ob~ects, features and advantages of the invention will
be apparent from the following more particular description
of a preferred embodiment of the invention as ill~latrated
in the accompanying drawings.
Brief Des _iption of_the Drawings
Figure 1 is an exploded perspec~ive view, partly
broken away,showing the rehydrator according to the present
invention.
Figure 2 is a perspective view of a tray having a
plurality of individual receptacles or wells therein.
Figure 3 is a cross-sectional side elevation view
showing one of the syringe-like elements and the guide
means for guiding the second plate for movement relative
to the first plate~
Figure 4 is a view similar to Figure 3 showing the
second plate in engagement with the first plate.
Figure 5 is a detailed showing, partly in section, of
the barrel and plunger assembly immersed in a fluid
prior to picking up~ a predetermined quantity of the fluid.
Figure 6 is a view~similar to Figure 5 showing the
barrel and plunger retracted out of the fluid with a
predetermined amount of the fluid withdrawn into the
end of the barrel by the plunger.
- Figure 7 is a view similar to Figure 6 showing the
fluid within the barrel about to be ejected thèrefrom by
the downward movement of the plunger into a receptacle.
Detailed Description of the Invention
The rehydrator as shown in Figure l is comprised of a
first plate 10 having a plurality of apertures 12
therethrough which are arranged in a plurality of rows.
A plurality of hollow cylindrical barrels 14 are secured
in each of t;he apertures 12 and protrude downwardly from
the lower side o the plate 10. All o the barrels 14
are of equal length and may be s~ucured in the~aper~ures
by press fitting or other suitable means. Four stepped
apertures 18 are also formed through the plate 10 and
four guide posts 20 are secured in the smaller diameter
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portion of the aperatures 18 and extend upwardly from
the plate 10. A second pla~e 22 is disposed parallel
to the plate 10 and is provided with a first plurality
of stepped apertures 24 equal in number to and aligned
with the apertures 12 in the first plate 10. Four
additional stepped apertures 26 are also formed in the
plate 22 in alignment with the stepped apertures 18 in
the plate 10. A ring 28 of antifriction material such
as teflon or the like is seated in the enlarged diameter
portion of the aperture 26. A spring 30 surrounds the
- guide posts 20 and is seated at one end on the enlarged
diameter portion of the aperture 18 and is seated against
the bearing ring 28 in the enlarged diameter portion of
the aperture 26. The upper end of the guide post 20 is
provided with three grcaves 32 adapted to receive a C
. clip 34 which will pro~ide an upper limit stop for the
plate 22 as it is biased upwardly by the spring 30. The
spacing between the plates 10 and 22 can be ad~usted by
locating the C clip 34 in a di~fferent one of the grooves
32.
A plurality of plungers 36 are slidably mounted in the
barrels 14 and extend into the stepped apertures 24 at
their upper ends. The upper end of each plunger 36 is
provided with a rounded end 38 and a groove 40 into
which a C clip 42 is snapped. The C clip 42 is adapted to
rest on the shoulder of the stepped aperture 24 so that
upon upward movement of the plate 22 relative to the plate
10, the plungers 36 will be moved upwardly within the
barrels 14. A cover plate 44 is secured to the~upper
surface of the plate 22 by means of a plurality of screws
46. The cover plate 44 covers the apertures 24 to prevent
the removal of the plungers 36. However, a plurality of
~ apertures 48 are provided in alignment~with the stepped
; apertures 26 in tXe plate 22 to accommodate the upper
ends of the guide post~ 20.
The guide post 20, the plungers 36 and the barrels 14
are so dimensioned relative to each other that the parts
will be disposed in the manner shown in Figure 3 when the
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plate ~2 is biased away from the piate 10 to the fullextent permitted by the adjustable clip 34. When the
plate 22 ls pressed downwardly into engagement with the
plate 10 as shown in Figure 4, the lower end of the plunger
36 will extend beyond the lower end of the barrel 14 and
the spring 30 will be completely compressed within the
recess defined by the two enlarged diameter partion of
the apertures 18 and 26. The external diameter of the
plungers 36 is somewhat smaller than the internal diameter
of the barrel 14 so that substantial clearance is provided
as best seen in Figures 5-7. As a result of this substantial
clearance, the tolerances required in aligning the plungers
with the barrels are fairly broad, thus, simplifying
and expediting the manufacturing procedure.
The assembly as described above may be housed in a
suitable frame work or housing depending upon the particular
use to which the dispenser will be put. A simplified
example of such a housing is constituted by the wall
portions 50 which are secured to and depend downwardly
from the edges of the plate 10. The distance to which the
walls 50 extend below the undersurface of the plate 10
is greater than the distance the lower end of the plunger
36 extends below the undersurface of the plate 10 when
disposed in the position as shown in Figure 4. Thus, the
lower edges of the walls 50 will properly space the lo:wer :
end of the plunger 36 and accordingly, the lower end of
the barrel from the bottom of a fluid reservoir 52 by a
predetermined amount. Thus, if the reservoir 52 is filled
to a predetermined level, the lower end of the plunger
36 as well as the lower end of the berrel 14 will be
disposed below the surface of the fluid within the
reservoir. Since the plunger is extending beyond the end
of the barrel below the surface of the fluid, the surface~
tension will be broken and the end surfaces of the:plunger
will be thoroughly wetted as shown in Figures 4 and 5.
The plunger is then withdrawn into the barrel 14 and due
to the liquld se~l S l~rmed ~etw,en the int~ri~r s~r~ace
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of the barrel and th~e bottom edge of the plunger, a
predetermined amount of fluid will be drawn into the
barrel and the barrel may then be withdrawn from the 1uid
F as shown in Figure 6. A micro~ray 50 having a plurality
of wells 62 formed therein corresponding to the nu~ber of
barrel and plunger assemblies can then be located bensath
th& respective barrel and plunger assemblies as shown in
Figure 7. Upon depression of the plurality of plungers
in the direction of the arrow in Figure 7, the fluid held
within the lower end of the barrel will be dispenséd into
its respective well 62. The plunger assembly 70 comprised
of the plates 22 and 44 and the plurallty~of rods 36 can
be reciprocated by means of a suitabIe actuator 72 as
shown in Figure 1. The acutator may be fludic, mechanical
or electrical and it may be mounted in a suitable frame
or housing secured t~ the plate lO similar to the manner
in which the actuator 11 of the Sekine patent 4,047,438
is mounted in the houslng 8 secured to the plate 3.
The state-of-the-art in microtube tray methodology
calls for drying the test reagents in the microtube tray
54 as opposèd to~freezing until ready for use. The
advantages of t~he drying instead of freezing are an
increased shelf-life and the elimination of the problem
of thawing during transportation. However, the use~of
dried reagents presented a problem in reco~nstitutlng the~
reagents just prior to use since it was extremely difficult
to accomplish this simultaneously, accurately and~
economically. The rehydrator according to the present
invention picks up from the fluld reservoir 52 and dispenses
a fixed amount, f~or example 100 ~1 oE fluid into each
well of a ml~crotube~tray 54. The rehydrator performs
like a battery of syringes held in the exact configuration
of the wells of the~microtube tray. However, a battery of
syringes would~be~very costly as well as time consuming in
35~ the sterilization and cleaning process as there might be
up to 176 wells to be filled~ a tray. According to the
present inventlon,~the plunger sssembly can readily be
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disconnecte~ Erom the barrel assembly and the parts
easily and efficiently sterilized. The materials used
should be stainless steel, aluminum or the like which
are susceptible to being autoclaved.
The rehydrator according to the present invention is
also much easier to assemble than a battery o~ syringes
since the tolerances can be much greater and there is
no need for airtight seals between the plungers and the
barrels. Since the ends 38 of the plungers are rounded,
there will be substanitally point contact with the cover
44 during downward movement of the plunger assembly to
avoid any problems which might arise due to misalignment
of one of more barrels.
The housing or frame constituted by the walls 50
could be a separate structure upon which the plate 10
would merely rest during the pickup and dispensing
procedure so that the housing 50 would not have to be
sterilized after each operation.
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