CA1042843A

CA1042843A - Method and device for racking and sealing containers

Info

Publication number: CA1042843A
Application number: CA263,552A
Authority: CA
Inventors: Richard Mencarini; Carlton D. Deaton; Douglas P. Stockdale; Ralph M. Owen
Original assignee: Baxter Travenol Laboratories Inc
Current assignee: Baxter International Inc
Priority date: 1976-01-14
Filing date: 1976-10-18
Publication date: 1978-11-21
Also published as: US4040234A; DK561876A; NO764226L; BR7608789A; NL7612464A; ES454690A1; BE850331A; IL50674A0; SE7700272L; IT1064437B; JPS5288089A; DE2658432A1; FR2338078B3; FR2338078A1; ZA766272B

Abstract

ABSTRACT OF THE DISCLOSURE

A rack assembly comprising mounting means for containers, e.g.. test tubes, a lid spaced from said mounting means which coope-rates with orifices in the containers, a flexible sealing sheet for seal-ing the orifices interposed between the lid and mounting means, and means for spacing the lid from the mounting means and for gripping the sealing sheet. Containers are inserted in the mounting means.
The sheet is them placed over the containers, and the lid in turn placed over the sheet so that the sheet seals the container orifices as the containers are maintained in substantially fixed position by the mounting means. By agitating the rack assembly the containers held therein are also shaken. The rack assembly is easily re-used by stripping off and discarding the sealing sheet.

Description

~04Z843 BACKGROUND OF THE INVENTION
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This invention broadly relates to racks for simultaneously spacing, holding and sealing a plurality of containers and to a method for using said racks to seal the containers and agitate the contents of the sealed containers. Specifically, it relates to racks having a base for supporting the containers, at least one means for aligning the containers in a substantially uniform spaced relationship, a lid for sealing the orifices in the aligned containers and an assembly or clamping system for forcing the lid down upon the container open-ings as well as maintaining in fixed relationship the base and means for aligning the containers. In one specific embodiment, it relates to test tuhe racks having a base for the test tubes, perforated plates substantially parallel to the base and spaced above the base to space the test tubes and hold them upright. a lid having a portion which fits over, onto, into, or in other cooperative relationship with the test tube openings, a flexible sealing sheet disposed between the lid and the test tube orifices to seal them, and a device for clamping the lid and sealing sheet into place over the test tubes. Still more specificaily~ this invention relates to the structure employed to seal the openings of the test tubes, and to the method of sealing involved therein.
~, U. S. Patent 2, 725, 782 discloses a test tube rack having a hinged top that swings down over a racked row of test tubes and is , then latched in place. The underside of the top is lined with a flat sheet of sealing material. Other patents of interest in this connec-`` 25 tion disclose a test tube rack having a lid with caps attached (U. S.
3, 483, 997) or stoppers attached (U. S. 3, 098, 721 and 3, 752, 651).

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)4Z843 Threaded or snap-on single container caps having resilient seals are known. Il. S. 2, 582, 566, U. S. 3,219, 222 and U. S.
3, 272, 369 all disclose threaded caps having resilient portions which deform in conformance to the lip of the container and thus effect a seal. V. S. 3, 896, 959 discloses a foam-backed resilient seal for a snap-on container cap.
Il. S. 3, 682, 323 teaches the use of axially flanged or grooved cylinders for spacing the component plates in a test tube rack.
In various chemical processes, particularly analytical pro-cedures, a large number of batch reactions are desirably performed - simultaneously with a minimum of manipulative steps. Such steps generally entail either mixing or suspension of materials, or both.
It is important to perform the mixing or suspension step without leakage of container contents while ensuring rapid and complete mixing or suspension. Furthermore, it is often desired to perform the step using the container in which the remainder of the process `l, occurs. Hence test tube or reaction container racks are needed which allow the technician to seal a plurality of containers simul-taneously and then agitate the whole structure until suitable mixing or suspension has been achieved. Further, when the rack and lid are to be reused it is imperative that the device provide for a rapid exchange of containers and seals without incurring cross-contamina-` tion or the necessity of washing any of the rack components.
` 'rhe prior art has failed to satisfy the foregoing require-ments. The known test tube racks do not provide for ready reuse in that no provision is made for providing a renewable sealing surIace.
Further prior art racks having lids with a flat, rigid-backed sealing "

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1~4Z843 material often fail to seal satisfactorily, particularly ~hen employing containers with irregular lips, e.g. disposable test tubes. Lids having protruding caps or stoppers can be time-consuming to align and effectively seal.
Therefore, it is a general object of this invention to provide a rack for holding a plurality of containers such as disposable test tubes, and for rapidly and effectively sealing -the containers.
It is a further object of the lnvention to provide a 10 rack having a lid for sealing a plurality of containers held in -the rack, the rack being constructed for the rapid renewal or replacement of a flexible sealing member interposed between the ; lid and orifices in containers held in the rack.
It is another object of the invention to provide a rack for holding a plurality of containers wherein the container $ orifices are sealed by stretching and holding a flexible membxane ; over the openings in the containers.
It is another object of the invention to provide a method using the rack of the invention whereby a plurality of containers can be sealed and agitated.
According to the present invention there is provided -a rack for holding and sealing a plurality of containers having orifices, the rack including mounting means for supporting and indexing a plurality of containers in predetermined substan-~ tially horizontal spaced relationship. A lid is provided ;i opposite the mounting means having at least one rigid surface broken with apertures, each aperture being capable of receiving j at least one of the orifices. A flexible sheet is provided for ~ sealing the container orifices, the sheet being disposed between ; 30 the mounting means and ~he lid apertures. A spacing means places the lid and mounting means at a distance predetermined ~-~-to permit the orifices to penetrate the apertures without .

i jk~J~i l~J4~843 abutting the lid, and fo~ removably fixing the sealing sheet between the lid apertures and the mounting means.
According to an embodiment of the invention, the mounting means generally comprises a base for maintaining the bottoms of the containers in the same plane when downward force - is exerted on the containers, and an alignment means having holes or sleeves into which the containers are inserted for orientation into a predetermined relationship whereby any sub-stantial side-to-side motion of the container orifices is pre-10 vented. `
The lid includes a sealing portion which may be a -plurality of recesses or apertures. The apertures may be -present in protrusions studding the bottom of said lid, they ;
may be formed by ridges present on a planar surface of the lid, or they may simply be holes passing partly or entirely through the lid.
The spacing means is a device such as a clamp, post or slotted wall which will space the lid from the mounting means and also clamp or reversibly maintain the flexible sheet between the lid and the mounting means. This latter function serves to hold the sheet, particularly the outer portions there-of, in place as it is stretched by the container orifices pro-truding into the lid sealing portion. The former function serves to limit the degree to which the orifices are permitted ,'. to protrude into the sealing portions of the lid. The spacing -i means may consist of single or multiple elements.
-~ The process according to the present invention re- ;
lates to simultaneously sealing a plurality of containers, each of which includes an orifice. The process includes the st~ps ~. ~.-of placing a plurality of containers in a mounting means for suppcrting and indexing the containers and placing a flexible sealing sheet over the container orifices. A lid having ~k~

~042843 rigidly defined apertures is placed over the container so that the apertures correspond to the container orifices, and the lid is forced down upon the containers to first rigidly clamp the sheet in place and then to stretch the sheet over the orifices as the orifices enter the apertures.
The inventive rack may be used, therefore, in pro-cesses where mixing or other agitation of materials in a plurality of containers is desired, although the device is also operative with single containers. The containers, such as test tubes, cuvettes or bottles, serve as receptacles for liquids, solids and suspensions. These materials are conveniently added while the containers rest on the base, held in an upright position and indexed position. When the desired materials have been added to the containers, the sealing sheet is placed in position over the container orifices and at a point where it can be engaged by the spacing means. The lid is then aligned over ~ the containers so that the sealing portions in the plane of the lid facing the containers coincide with the orlfices in the con- -~
. tainers, and the spacing means engages the sheet, lid, and mounting means to complete the assembly of the rack. The sheet is then held in place by the spacing means and pulled taut over the container orifices as the orifices are brought into coopera-- tive sealing relationship with the sealing portions of the lid.
While this is occurring, the containers abutt the base. Thus, `
any irregularities in the container orifices are of no moment as the sheet is stretched into conformance with each imperfection in the orifice. The entiré device may then be shaken or agitated as desired with no leakage of the containers.

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~ 6--jk/, j Following agitation the assembling means is disengaged, the lid removed and the sheet stripped off the container orifices.
The containers may then be employed as desired, new containers installed in the aligning means, a fresh sealing sheet placed in po-sition and the above procedure repeated. The device therefore provides both for the rapid renewal of the sealing sheet and the convenient, effective and simultaneous closure of the container -~ orifices.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is an exploded view of a preferred embodi-ment of the rack assembly of the present inventionJ with all but one container omitted for clarity of presentation.
FIG. 2a is an enlarged partial cross-sectional view taken generally along the line 2a - 2a of FIG. 1 prior to engagement of the lid and sealing sheet.
. FIG. 2b is an enlarged partial cross-sectional view ~,1 taken generally along the line 2b - 2b of FIG. 1 after engagement of the lid and sealing sheet.
FIGS. 3a - 3c are sectional views similar to the right side of FIG. 2a showing several additional embodiments of the lid sealing portions.
: FIG. 4 is a cut-away front view of an additional embodi-ment of the container mounting means.
FIG. 5 is a partial cross-sectional view along lines , 5 - 5 in FIG. 1.

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~ -DESCRIPTION OF THE PREFERRED EMBODIMENTS
A rack assembly for holding and sealing a plurality of con-tainers is shown in FIG. 1. A base 10 supports containers such as - test tubes which fit with minimal tolerance through a plurality of alignment holes 11 and ll'in indexing panels 12 and 12. Panels 12 and 12'are spaced above base 10 and held in place by six posts 13. The posts 13 are composed of a series of progressively nar-rowing shoulders_, 15, 16 and 17. The shoulders are inserted_ _ into corresponding receptacles 18, 19, 20 and 21, respectively, whereby the base 10, panels 12 and 12,/ and lid 22 are supported upon and spaced by the shoulders 14, 15, 16 and 17, respectively.
' Thus the rack in the preferred embodiment is assembled by placing the posts 13 through the corresponding receptacle holes in the base 10 and panels 12 and 12. The device is then ready for insertion of the containers 27 through the plurality of alignment holes 11 and 11.
Following insertion of the containers 27, sealing sheet 26 (shown '. cut-away in FIG. 1) is placed over the containers. The sheet 26 is then pulled taut as the posts 13 are inserted into receptacle 21 until shoulder 17 abutts the lid 22 and each container 27 protrudes into recessed apertures 28 in lid 22. The sheet 26 is thus firmly held in pcsition and the containers are sealed as the apertures force the sheet 26 into sealing relationship with the orifices 27a of containers 27, as shown in FIGS. 2a - 2b.
The foregoing sequence of assembly is demonstrated in FIGS. 2a and 2b. FIG. 2a illustrates post 13 and container 27 as they advance into the post receptacle 21 and aperture 28, respectively, "3 ~ ~ - 8 - ~
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)4Z843 in lid 22. The sheet 26 may be pulled taut manually or by associated apparatus. However, this is generally not essential because the pro-trusion of containers 27 into apertures 28 upon assembly serves to pinch the sheet 26 between lid 22 and posts 13 and to deform or stretch sheet 26 between container 27 and the underside of lid ~, . thus yielding a highly effective seal. FIG. 2b shows the device in the sealed mode. Here, sheet 26 is secured to lid 22 by shoulder 17 of post 13 as well as by container 27.
FIGS. 3a and 3c illustrate alternative embodiments for the apertures 28 in lid 22. The embodiment of FIG. 3a is particularly adapted for use with test tubes; the rounded protrusion 29 projects into the mouth of a test tube and thus enhances stretching of the seal-ing sheet.
FIG. 3b features an aperture having rounded edges 30 rather than the sharp angles illustrated in FIGS. 2a and 2b. These rounded edges, as well as the slanted edge 31 (as shown in FIG. 3a) serve to guide the container orifice to a central orientation in the aperture 28, thereby obviating any tendency of the orifice to tear the sealing sheet.
Some guidance for the container is usually preferred because the con-tainers may wobble slightly in the alignment holes 11 and 11. These -,j holes are slightly larger than the outer dimensions of the container so as to permit easy insertion and withdrawal from the alignment means. However, even when no guidance to the container is provided ` the flexibility of the sealing sheet is normally sufficient to effect seal-d 25 ing.
FIG. 3c shows an additional example of a suitable aperture.
Aperture 28 is formed by ridges 32 protruding from the plane of the lid.

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~04Z843 FIG. 4 is a mounting means 33 comprising a base portion 34 and upright indexing sleeves 35 formed as a composite single unit instead of as a plurality of members as in the FIG. 1 embodi-ment (see members 10, 12 and 12 in FIG. 1). The aim here is also to limit wobbling of the containers 27 as much as possible commensurate with ease of container insertion and removal. This is accomplished in FIG. 4 by providing sleeves 35 in place of the holes 11 and 11 in FIG. 1. Moreover, in the FIG. 4 mounting means, the functions of the base and indexing means are combined into a single, integrally manufactured unit. The mounting means 33 may be used with a lid, sheet and posts in a manner similar to that of , FIG. l.
FIG. 5 illustrates the base 10 in partial cross-sectional view through lines 5 - 5 in FIG. 1. This view shows depressions 36 which cooperate with the base 27b of container 27 to aid in firmly indexing the container.
In a preferred embodiment, the height of shoulder 17 is optimized so that lid 2~ and base 10 are brought sufficiently close to stretch the sealing sheet 26 over the orifice, but not so close as to bring the container orifice into abutting contact with lid 22 or the aperture 28 of lid 22, as shown in FIG. 2b. The invention is in-tended to encompass both the indirect contact seal just described, .i as well as one in which the orifice abutts the lid 22 with the sheet 26 acting as a sealing cushion.
The containers of choice for use with the invention are pre-ferably disposable glass test tubes such as those used in performing chemical and biochemical analysis, although the utility of the rack ` -10-.

1~4Z843 assembly with many other containers will immediately be apparent to those skilled in the art. These test tubes are inexpensive and, being so, are usually made to somewhat liberal tolerances. Fur-ther, they are generally small, for example lOmm x 75mm. In a .
disposable test tube of this size, the length between tubes may vary as much as 3mm while the lip in any one tube may vary as much - as 1/32 inch. Tubes having tolerances of this nature are readily sealed by the inventive device.
The sealing sheet may be any flexible material capable of stretching into the lid depressions under pressure from the container orifices and which is inert to the process being performed in the containers. Thus the chemical nature of the sheet is of no signifi-cance as long as it is non-reactive with the test tube contents. Il-lustratively, sheets formed of polymeric hydrocarbons such as poly-vinyls are satisfactory. Parafilm(~), a polysheeted paraffin, is an example of one preferred sheet material. The sheet may also have a surface treated to specifically aid in sealing, e. ~., an inert adhesive may be applied.
The rack is preferably constructed of polymeric plastic , 20 such as an acrylic resin as these are relatively inexpensive sub-stances and easily worked. Further, they are capable of maintaining ! a substantially rigid conformation, as is desirable in sealing a plu-- rality of containers. Furthermore, plastics do not abrade glass cuvettes if these are the containers of choice. A plastic having the physical characteristics of methyl methacrylate or polystyrene, including high mechanical strength, rigidity and light weight, i9 pre-~i .~ -11-.~
., ~ 104Zt~43 ferred. Other maierials, e. g., mctals~ can, of course, also be used if desired.
The base may be employed to aid in indexing of the con-tainers if the upper surface of the base is scored or milled to con-form to the container bases, e. g., as with a dish-shaped depression when test tubes are to be used. Further, the base and alignment . means may be integrally molded with the posts or other assembly means to form a unitary body, as described supra. The lid may be hinged or in any other fashion assembled to the remainder of the device. However, the lid should be both rigid and removable for withdrawal and insertion of the sealing sheet; That portion of the spacing means that serves to removably fix the sealing sheet between the lid and mounting means may be located upon the lid as a clamp, screw, plug or other structure for removably affixing the sealing sheet to the lid. The apertures in the lid can also be extended entirely through the lid to form holes so long as the lid remains sufficiently rigid to effect sealing. The lid and the base may include r a gripping means such as finger depressions to aid in shaking the i rack.

The above preferred embodiments and other specific infor- -mation contained herein are for purposes of illustration only, and such alterations and modifications thereof as would be apparent to those ski]led in the art are deemed to fall within the scope and spirit of the invention, bearing in mind that the invention is defined only by the claims appended hereto. -, ~

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Rack for holding and sealing a plurality of containers having orifices, the rack comprising in combination:
a. mounting means for supporting and indexing a plurality of containers in predetermined substantially horizontally spaced relationship;
b. a lid opposite the mounting means at least one rigid surface of which is broken with apertures, each aperture capable of receiving at least one of the orifices;
c. A flexible sheet for sealing the container orifices, said sheet disposed between the mounting means and the lid apertures; and d. a spacing means for spacing the lid and mounting means at a distance predetermined to permit the orifices to pene-trate the apertures without abutting the lid, and for removably fixing the sealing sheet between the lid apertures and the mounting means.

2. A rack for holding and sealing a plurality of con-tainers each having a protrusion which includes an orifice, the rack comprising in combination:
a. a base supporting the containers and preventing the passage of containers therethrough;
b. an indexing means communicating with said base for maintaining the containers in predetermined lateral relation-ship;
c. a lid having at least one rigid surface broken with apertures, each aperture capable of receiving at least one of said protrusions;
d. a flexible sheet for sealing the container orifices, said sheet disposed between the indexing means and lid; and e. spacing means communicating with the lid, base and indexing means for i. orienting the lid apertures so that the apertures receive at least a portion of the container protrusion, and ii. clamping the flexible sheet to the perimeter of the rigid surface of the lid so that the sheet is rigidly clamped in place until becoming freely removable from the lid upon disengagement of the lid and spacing means.

3. The rack of claim 2 wherein the base is a plate.

4, The rack of claim 2 wherein the indexing means is a plate having a plurality of holes adapted to receive the containers.

5. The rack of claim 2 wherein the indexing means comprises a plurality of sleeves for holding the containers upright.

6. The rack of claim 2 wherein the apertures pass entirely through the lid.

7. The rack of claim 2 wherein the flexible sheet is a polysheeted paraffin.

8. The rack of claim 2 wherein the base contains de-pressions conforming to the container bottoms.

9. The rack of claim 8 wherein the depressions are dish-shaped.

10. The rack of claim 2 wherein the lid comprises a plate having apertures in one side thereof.

11. The rack of claim 10 wherein the apertures have rounded edges.

12. The rack of claim 10 wherein the apertures have slanted edges.

13. The rack of claim 2 wherein the apertures are in rows and the indexing means orients the containers in rows whereby the container orifices are aligned with said apertures.

14. The rack of claim 13 wherein the apertures have slanted edges.

15. The rack of claim 13 wherein the apertures have rounded edges.

16. The rack of claim 2 wherein the spacing means comprises a plurality of posts, each post extending between the base and lid and passing through the indexing means.

17. The rack of claim 16 wherein each post includes at least four shoulders having incrementally increasing diameters from top to bottom and wherein the indexing means comprises two separate holed panels disposed between the base and lid, and wherein the lid, indexing means and base include receptacles for the post shoulders, whereby the posts may be inserted to obtain a rigid assembly.

18. The rack of claim 16 wherein the spacing means comprises six posts.

19. A rack for holding and sealing a plurality of test tubes, the rack comprising in combination:
a. a base having a pattern of dish-shaped depressions on its upper surface;
b. at least one indexing plate above the upper surface of the base having a pattern of holes corresponding to the pattern in the upper surface of said base, each hole for holding a test tube upright;
c. a lid opposite said at least one indexing plate and having one rigid surface broken with substantially square apertures in the same pattern as the holes in said at least one indexing plate;
d. a flexible sheet for sealing the test tubes, said sheet disposed between said at least one indexing plate and the lid; and e. a plurality of posts having shoulders of incrementally decreasing diameter joining the perimeters of said base, said at least one indexing plate, said lid and said flexible sheet, for i. spacing the base, the indexing plate and the lid; and ii. clamping the flexible sheet only between the upper post shoulders and the perimeter of the lid so that the sheet is freely removable upon disengagement of the lid and posts.

20. The rack of claim 19 wherein the holes in the in-dexing plate are sufficiently large to permit the tubes to wobble.

21. The process for simultaneously sealing a plurality of containers, each of which includes an orifice, comprising, a. placing a plurality of containers in a mounting means for supporting and indexing the containers;
b. placing a flexible sealing sheet over the container orifices;
c. placing a lid having rigidly-defined apertures over said containers so that the apertures correspond to the container orifices;
d. forcing the lid down upon the containers to first rigidly clamp the sheet in place and then to stretch the sheet over the orifices as the orifices enter the apertures.

22. The process of claim 21 wherein the sheet is clamped only at the perimeter of the lid.