IE903996A1 - Hinged centrifuge tube adapter - Google Patents

Abstract

An adapter for a centrifuge tube comprises two segments that are hinged along a hinge axis that extends perpendicular to the axis of the adapter,

Description

H1NOSB GENTBITUGS-TUBE APACTSR BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an adapter for holding a centrifuge tube in a centrifuge rotor cavity, and in particular, to an adapter having two segments Joined by a hinge, the hinge axis extending perpendicular to the axis of the adapter.

Description m the operation of a centrifuge it is important that the size and shape of the tube in which a liquid sample is carried closely conforms to the size and shape of the cavity In the centrifuge rotor in winch the tube is received. During centrifugation the centrifugal force exerted on the tube itself and the liquid therein acts to deform the centrifuge tube. A centrifuge tube which does not closely conform to the rotor cavity may thus be deformed lo the point of rupture. Even if the tube does not rupture the deformation may make the tube difficult to remove from the rotor cavity.

Moreover, even if the deformed tube is removable from the rotor, the return of the tube to its undeforrned shape may agitate the contents of the tube to an extent that destroys the sample separation.

When the shape and size of a centrifuge tube does not closely conform to the shape and size of the rotor cavity in which it is to be disposed a device known as a tube adapter is usually employed. The tube adapter has an interior cavity having a shape and size which closely conforms to the shape and size of the centrifuge tube being adapted. The exterior shape and size of the adapter closely conforms to the shape and size of the rotor cavity hi which is is to be used. The adapter serves to support a tube within the cavity In which It Is received and thus serves to prevent deformation of the tube during centrifugation.

Exemplary of an adapter formed of a single unitary member is the device disclosed in United States Patent 4,304,356 (Chulay et at). This adapter supports only the neck region of the centrifuge tube and is fabricated of a material having a lower density than the liquid being being carried therein to prevent bottoming of the adapter in the rotor cavity in the event of tube rupture.

Exemplary of an adapter formed of two piece construction is the device shown in United States Patent 3,674,197 (Mitchell et al.), assigned to the assignee of this invention. This adapter comprises two discrete segments, each of which has an indentation Uiereln. When Joined the indentations form a recess for receiving a collapsible bag during centrifugation.

An adapter arrangement formed of two discrete adapter segments and useful to support the capped end of a centrifuge tube is available as part of the Nalgene Ultra-Lok Tube System sold by Fisher Scientific Incorporated.

United States Patent 4,692,137 (Anthony) discloses a tube adapter having two segments which are hinged along the lateral edges of the segments. The hinge axes align in parallel relationship to the axis of the cavity in which the adapter is received. The disposition of hinges along the lateral edges of the segments is believed disadvantageous in that such a disposition may interfere with the insertion or removal of the ; adapter into or from the rotor cavity.

SUMMARY. QT THE..lMVSmQM The present invention relates to an adapter having an axis therethrough for supporting a centrifuge tube within a cavity In a centrifuge rotor. The cavity itself has an axis therethrough, with the axis of the adapter, in use, aligning in parallel relationship with the axis of the cavity. The adapter comprises a first and a second adapter segment, each segment having an exterior surface and a mating surface thereon. Each segment has an indentation in the mating surface thereof. The segments are connected by at least one hinge that supports the segments for relative pivotal movement about a hinge axis from an open to a mated position. In accordance with the present Invention the hinge axis extends perpendicular to the axis of the adapter.

When in the mated position the mating surfaces of the 10 segments are in contacting relationship and the indentations therein cooperate to define a recess having a predetermined shape. In one embodiment of the adapter of the present invention, used with a centrifuge tube having a body with a neck thereon in which a portion of the neck has a constricted region when the tube is capped, the indentation in each segment is shaped such that when the segments are in the mated position the recess is sized to closely correspond to the configuration of at least the neck of the tube. In tills embodiment at least one of the segments has a feature on the mating surface thereof that projects into the indentation therein. When the segments are in the mated position and the neck of the tube is received within the adapter the feature is received within the constricted region of the neck of the tube. A collar may be provided to prevent the bottoming of the tube in the cavity.

In another embodiment of the adapter of the present Invention the indentation in each segment is shaped such that when the segments are in the mated position the recess so defined is sized to closely correspond to the size and configuration of the centrifuge tube over Its entire length.

BRIEF DESCRIPTION QF THE DRAWINGS The invention will be more fully understood from the following detailed description thereof, taken in connection with the accompanying drawings, which form a part of this application and in which: Figure 1 is an exploded perspective view of an adapter according to a first embodiment of the present invention for supporting the neck region of a centrifuge tube of the type in which a portion of the tube neck has a constricted region thereon when capped, the adapter being shown in the open position: Figure 2 is a fragmentary elevation view, in section, of the 10 tube adapter of Figure 1 in use and supporting the neck portion of a centrifuge tube in a fixed angle rotor cavity; Figure 3 an exploded perspective view of an adaplct' according to a second embodiment of the present invention for supporting the full length of a centrifuge tube within a rotor cavity, the adapter being shown in the open position: , Figure 4 is a fragmentary elevation view, in section, of the tube adapter of Figure 2 in use and supporting a centrifuge tube over its entire axial length in a fixed angle rotor cavity; Figure 5 is a perspective view similar to Figure 3 of a 20 modification of the embodiment of the tube adapter there shown for use with an open top tube; and Figure 6 is a fragmentary elevation view, in section, of the centrifuge tube adapter of Figure 5 in use and supporting a centrifuge tube over its entire axial length in a fixed angle rotor , cavity.

DETAILED DESCRIPTION OF THE INVENTION Throughout the following detailed description, similar 30 reference numerals refer to similar elements in all Figures of the drawings.

Figure 1 is an exploded perspective view of an adapter, generally Indicated by the reference character 10, according to a first embodiment of the present invention. The adapter 10 in accordance with tills embodiment is useful for supporting a centrifuge tube T of the type having a body portion B with a closed end C, the body B tapering through a transition region R to a narrowed neck region N. The neck N serves as the liquid port through which a liquid under test may be loaded into the tube T. When the tube T is capped at least one portion D of the neck N becomes radially Inwardly constricted, thereby forming a constricted region In the neck of the tube. Preferably the capping assembly disclosed m United States Patent 4.552,278 (Romanauskas) is used to cap the tube, so that the neck N of the tube has a corrugated configuration imparted thereto, The corrugated configuration has at least one but preferably a plurality of circumferentially extending corrugations formed in the neck N. It should be understood that any other capping arrangement may be used, so long as any form of constricted region is imparted to the configuration of the neck N. , The adapter 10 is comprised of a first adapter segment 12 and an identical second adapter segment 14. Each segment 12, 14 has an exterior surface 16 and a planar mating surface 18 thereon. The exterior surface 16 of each segment is defined by a generally cylindrical lateral surface portion 20 and a planar upper surface portion 22. hi the preferred instance an enlarged collar 24 is disposed intermediate the lateral surface portion 20 and the upper surface portion 22. When the segments 12, 14 are mated together the mating surfaces 18 thereof arc Joined in abutting contact. As will become clearer herein the member so produced has an axis 1OA (best seen in Figure 2) extending therethrough. As is best seen In Figure 2 the configuration and size of the adjacent lateral surface portions 20 closely corresponds to the configuration and diameter of a rotor cavity 40 in which the adapter 10 is used. The upper surface portions of the conjoined segments are accessible when the adapter 10 is received in the rotor cavity 40.

The segments 12 and 14 are connected and supported for relative pivotal movement with respect to each other by at least one hinge 26. The hinge 26 may take the form of a live hinge I bridging the upper surface portions 22 of the segments 12, 14, or may, If desired, take the form of a coined hinge. The term live hinge refers to a hinge type, typically made of a polypropylene material, which must be flexed or bent before the plastic Is cooled or permanently set. Such hinges are complete without secondary operations. The term coined hinge refers to a hinge that is cold-formed, usually by a stamping operation. The stamping operation creates a narrower and a thinner flexing region which defines a hinge. These forms of hinges are defined in the Handbook of Plastics and Elastomers, McGraw-Hill Hook Company 1Θ75, (Charlee A. Harper, Editor) at page 12-9.

However formed, in accordance with the present invention the axis 26A of the hinge 26, that is, the axis about which occurs the relative pivotal motion of the segments, extends perpendicular to the axis 10A of the adapter 1,0. This relationship of the hinge axis 26A to the axis 1OA of the adapter 10 is best illustrated in Figure 2.

The mating surface 18 of each of Lhe adapter segments 12, 14 has an indentation 28 therein. The indentation 28 in each segment 12, 14 corresponds to the size and contour of at least a portion of the tube T. Thus, when the segments 12, 14 are mated, the indentations 28 therein cooperate to define a recess 30 (Figure 2) that corresponds to the size and shape of at least a predetermined portion of the tube T that is received therein.

In the embodiment of Figure 1, in which the adapter 10 is configured and sized to support only the neck N and the transition region R of the tube T, at least one but preferably both indentations 28 contains a feature 34, in the form of a circumferentially extending ridge, that corresponds in size and is located complementarity to the position of the constriction D in the neck N of the tube.

The adapter 10 shown in Figures 1 and 2 is especially useful when the diameter of body B of the tube T is equal to the diameter of a cavity 40 in a centrifuge rotor 42, but the overall length L of the tube T is less than the axial length of the cavity.

; The rotor cavity 40 has an axis 40A therethrough that aligns in parallel relationship with the axis 10A of the adapter 10 when the same is disposed therein. In use, as Is best seen In connection with Figure 2, the adapter 10 defined by the mated segments 12, 14 serves to support the neck N and the transition region R of the tube T within the cavity 40.

To mount the tube T in the cavity, the tube T is inserted Into one of the segments 12, 14, so that the feature 34 on the segments) is received within the constricted region D in the neck N of the tube T when the segments are in the mated position. The segments 12, 14 are then pivoted about the hinge axis 26A to place the mating surfaces 18 thereon in abutting contact. This closes the adapter 10 around the tube T and thus permits the tube T to be manipulated by manipulation of the δ adapter 10. The tube T and the adapter 10 are then axially inserted into the cavity 40, The preferred instance the tube T bottoms against the closed end of the cavity 40.

The axial length of the adapter 10 is selected such that when the tube T is received in the cavity 40, the upper surface portions 18 on the segments 12, 14 are accessible to a user.

The hinge 26 may be formed so as to define a useful lifting appliance, as shown in Figure 2. Thus, to withdraw the tube T at the end of a centrifugation run, a user grasps the hinge 26 and lifts the tube from the cavity 40. It should be appreciated from 2δ the foregoing that the feature 34 in such an instance defines a lifting surface which acts against the material of the tube in the constricted region D in the neck N thereof, and thus selves to transmit the lifting force to the tube T to withdraw the same from the cavity. The tube T may is withdrawn without unduly agitating the separation within the tube T.

In some cases the rotor 42 may have a shoulder 44 defined about the mouth of the cavity 40. The shoulder 44 is preferably located on the rotor 42 at a position that is axially beneath the collars 24 on the segments 12, 14 when the adapter is received δ within the cavity, thereby to guard against the possibility that β tube rupture will permit the adapter 10 to enter into the cavity 40.

The segments 12. 14 with the hinge 26 therebetween are preferably Integrally formed from a suitable material, such as polypropylene. Of course, the segments 12, 14 may be otherwise fabricated from one or more pieces, using other manufacturing techniques and other materials, and assembled to define the adapter 10. Similar techniques may be used to form any other embodiment of the adapter illustrated and discussed herein.

For those instances wherein the diameter of the tube T is less than die corresponding diameter of the cavity 40 the adapter 10' shown in Figures 3 and 4 finds utility. In this embodiment of the invention the recess 30' (Figure 4} formed by the cooperative association of the indentations 28' ln the mated adapter segments 12', 14' is configured to correspond to the size and shape of the tube T over the entire axial length L' thereof. For this purpose the segments 12', 14’ are each provided with an axial extension 36 having a bottom wall 36.

The bottom wall 38 need not completely close the bottom of the adapter 12', 14, , as is illustrated, but may only partly close the same. Hie presence of the extension 36 and the bottom wall 38 permit the recess 30' defined when the segments 12', 14' are joined to receive the entire axial length L' of the tube T.

Figure 4 illustrates this embodiment of the invention In use. When the tube Τ' is received in the recess 30' the closed end C of the tube T is contacted by the interior surface of the bottom wall 38. Preferably the indentations 28' in the segments 12', 14' are placed such that the tube Τ' lies as close to the bottom of the rotor cavity 40, thereby to maximize the centrifugal force imposed on the liquid sample. It should also be noted that ln this embodiment of the invention the feature 34 present in the embodiment of Figure 1 is not required, since the requisite lifting force transmission surface is defined by the bottom wall 38 operating against the bottom end C’ of the tube g T. It is also noted that in this embodiment of the invention the collar 24 may be eliminated.

Figure 5 illustrates a modification of the embodiment of the invention shown in Figure 3. In this embodiment, the tube Τ' has the form of a test tube, with no constriction present to define a neck N. In this instance, the segments 12, 14 are modified to exhibit Indentations 26 similar to those shown in Figure 3, but which correspond in size and shape to the test tube T over the entire axial length L thereof.

In whatever one of the embodiments used, the hinge between the segments is disposed on the upper surface portion of the exterior surface of the adapter segments. Such a disposition Is believed advantageous in that it locates the hinge at a position where the hinge does not interfere with the receipt of the adapter within the rotor cavity. At the same time the hinge defines a useful lifting appliance.

It is noted that although the rotor cavity 40 is illustrated as being of the fixed angle type, the adapter 10 in accordance with any embodiment of the invention may also be used with equal efficacy in a vertical rotor. Moreover, it is within the contemplation of this Invention to use the adapter to support a tube or a predetermined portion thereof within a cavity provided in another adapter, thereby making the use of the adapter in accordance with this invention amenable for use in the 2δ; environment of a swinging bucket rotor.

Those skilled in the art, having the benefit of the teachings of the present invention may impart numerous modifications thereto. It should be understood that such modifications are to be construed to lie within the scope of the present invention, as defined by the appended claims.

Claims (8)

1. An adapter for supporting a centrifuge tube within a cavity in a centrifuge rotor, the tube having a predetermined size and configuration, the adapter having an axis extending 5 therethrough that, in use, aligns in parallel relationship with an axis of the rotor cavity in which the adapter is disposed, the adapter comprising: a first and a second adapter segment, each segment having an exterior surface and a mating surface thereon, each segment 10 having an indentation in the mating surface thereof, at least one hinge connecting the segments and supporting the relative pivotal movement, about a hinge axis, of at least one segment with respect to the other from an open to a mated position, the hinge axis extending perpendicular to the 15 s axis of the adapter, in the mated position, the mating surfaces of the segments being disposed in contacting relationship and the indentations therein cooperating to define a recess having a size and shape that corresponds to the size and shape of at least a portion of the 20 tube.

2. The adapter of claim 1 wherein the centriibge tube has a body with a neck thereon, a portion of the neck having a constricted region thereon when the tube is capped, the indentation in each segment being shaped such that 25 when the segments are in the mated position the indentations cooperate to define a recess that corresponds to the size and shape of the neck of the tube. at least one of the segments having a feature on the mating surface thereof that projects into the indentation therein such 30 that, when the segments are in the mated position and the tube is received within the adapter, the feature is received within the constricted region in the neck of the tube.

3. The adapter of claim 1 wherein the centrifhge tube has a 35 body with a predetermined configuration over its entire length, π ; the indentation in each segment being shaped such that when : the segments are in the mated position the indentations cooperate to define a recess that corresponds to the size and shape of the centrifuge tube over its entire length.

4. The adapter of claim 3 further comprising an enlarged collar disposed on the exterior surface of at least one of the segments.

5. The adapter of claim 2 further comprising an enlarged collar 10 disposed on the exterior surface of at least one of the segments.

6. The adapter of claim 1 further comprising an enlarged collar disposed on the exterior surface of at least one of the segments. - 12

7. An adapter for supporting a centrifuge tube within a cavity in a centrifuge rotor substantially in accordance with any of the embodiments herein described with reference to and as shown in the accompanying drawings.

8. The features described in the foregoing specification or any obvious equivalent thereof, in any novel selection.