Flip top cap

A cap is provided for a laboratory vessel. The cap includes a lid that can be rotated relative to the laboratory vessel from a closed position to an open position. The lid includes a shield for at least partly surrounding the open top of the laboratory vessel. Ribs are disposed on outer surfaces of the shield for receiving manual digital pressure for opening and/or closing the lid.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a flip top cap for use with laboratory vessels, such as tubes.

2. Description of the Related Art

Many laboratory procedures require tissue cultures or cell cultures to be stored and/or cultivated in a vessel, such as a tube or a flask. The typical tube includes a cylindrical side wall, a closed bottom and an open top. The closed bottom often is conically generated. The size of the tube varies from one laboratory procedure to another, and tubes typically will define volumes from 15 mL to 50 mL. Flasks also have a side wall, a closed bottom and an open top. For simplicity, the following discussion will describe tubes, but pertains to other laboratory vessels as well.

Many laboratory procedures require the tissue or cell cultures in the tube to remain sterile. Thus, the tube typically is provided with a cap for sealing the open top of the tube. However, the cap must be removed periodically to access the tissue or cell cultures in the tube.

Many caps are formed separate from the tube and have a portion dimensioned for telescoping partly into the tube and sealing with the inner surface of the side wall adjacent the open top of the tube. These caps may be formed from an elastomer or other resilient material to ensure sealing with the tube. Other caps include a substantially rigid collar surrounding portions of the cap that telescope into the tube. The collar can be telescoped over the open top of the tube and provides a region that can be gripped conveniently for removing the cap from the tube.

Laboratory workers generally place the cap top-down on a laboratory work surface while they are accessing the interior of the tube with a pipette to obtain a sample of the cell or tissue culture in the tube. Thus, the side and bottom of the cap do not contact the potentially non-sterile work surface. The cap then is repositioned in sealing engagement with the open top of the tube after the cell or tissue culture has been accessed. These tube and cap combinations require the laboratory worker to use two hands to remove the cap. Additionally, these tube and cap combinations create the potential that the cap will be positioned improperly on the work surface, thereby creating the potential for contaminants being transferred from the work surface to the tissue or cell culture in the tube.

Some tubes have been manufactured with a flip cap to permit one-handed opening and to avoid the need to place any part of the cap on a laboratory work surface while the interior of the tube is being accessed by a pipette. These tube and cap assemblies typically include a body that is threaded or otherwise mounted to the open top of the tube. A cap is connected to the body by a hinge, such as a living hinge. A laboratory worker holds the tube between the forefingers and the palm of one hand. The thumb of the same hand then is urged against the cap to move the cap out of engagement with the body so that the cell or tissue culture in the tube can be accessed. These flip top caps provide certain handling efficiencies and avoid the need to place the cap on the work surface in the laboratory while the contents of the tube are being sampled. However, prior art flip top caps require the user's thumb to pass directly over the open top of the tube. There is a high probability that the user's thumb will contact the open top of the tube while the cap is being rotated away from the open top of the tube. Contact of the thumb with the open top of the tube is likely to contaminate the tube and the tissue or cell cultures stored therein.

In view of the above, it is an object of the subject invention to provide a tissue culture vessel, such as a tube, that can be opened easily without significant risk of contamination to the contents of the vessel.

SUMMARY OF THE INVENTION

The invention is a cap for a laboratory vessel, such as a tube. The vessel includes an open top, and the cap includes a lid that is hingedly secured in proximity to the open top of the vessel. Thus, the lid can be rotated hingedly from a closed position where the top of the vessel is closed and an open position where the top of the vessel is open. The open position is angularly spaced from the closed position by at least 90° and preferably about 180°.

The lid of the cap may be joined to a body and the body may be mounted to the open top of the vessel. For example, the vessel may include an array of threads, and the body may include an array of mating threads for securely mounting the body to the vessel. The exterior of the body may be configured to facilitate threaded mounting of the body on the vessel. For example, the body may have ribs that extend parallel to the axis about which the threads are generated. Alternatively the exterior of the body may have bumps, depressions, roughening or other surface irregularities to facilitate gripping and rotation of the body relative to the vessel. The body and the lid may be joined unitarily to one another by a living hinge. The living hinge may be an over-center hinge that is biased towards a fully closed position and/or a fully opened position. Thus, the over-center hinge will assist complete opening and/or complete closing of the lid.

The lid preferably includes at least one external surface configuration to facilitate digital manipulation of the lid. At least part of the external surface configuration preferably is offset from a line that passes perpendicular to the rotational axis of the hinge at a location centrally along the hinge. The offset positioning of the external surface configuration offsets the thumb or forefinger of the user from the open top of the vessel, and hence reduces the possibility of contact with the open top of the vessel. Hence, the potential for contamination of cell or tissue cultures in the vessel is reduced. The external surface configurations can include ribs, tabs, bumps, depressions, textures or other such configurations on the lid to facilitate opening.

The lid preferably includes a shield disposed to at least partly surround the open top of the vessel when the lid is in the closed position. The shield is at a side of the lid opposite the hinged connection and preferably extends along at least portions of the lid that have the external surface configuration to facilitate opening. More particularly, the shield preferably is disposed between the vessel and the external surface configuration on the lid. Accordingly, the shield helps to prevent contact with the open top of the vessel as the lid is being opened by a thumb or forefinger. The shield also prevents contact with portions of the lid that seal the open top.

The lid may further include a skirt dimensioned to telescope into the open top of the vessel or into the open top of the body mounted to the vessel. The skirt is dimensioned for sealed engagement with the open top of the vessel or with the body to achieve sterile containment of cell or tissue cultures in the vessel. Outer circumferential portions of the skirt may include anti-splash features, such as notches. The notches or other such anti-splash features balance air pressure between the inside and the outside of the vessel during the initial stage of opening the lid, and hence reduce the possibility of spraying or splashing as the lid is opened. The shield and the tab are disposed to prevent inadvertent contact with the skirt while the lid is being opened.

DETAILED DESCRIPTION

A cap in accordance with a first embodiment of the invention is identified generally by the numeral10inFIGS. 1-9. Cap10is molded unitarily from resin and includes a body12and a lid14that are joined unitarily by a living hinge16. Hinge16enables lid14to be rotated approximately 180° between a fully open position, as shown inFIGS. 1-3, and a fully closed position, as shown inFIGS. 4-6. Additionally, hinge16has an over-center design configured to bias lid14through the final stages of rotation towards the open position ofFIGS. 1-3and through the final stages of rotation towards the closed open position ofFIGS. 4-7.

Body12includes a generally planar top wall18with a circular outer periphery20and a circular opening22concentric with outer periphery20. A short cylindrical inner wall24extends down from top wall18concentrically with circular opening22in top wall18. Thus, circular opening22and inner wall24define a short cylindrical sealing surface26facing inwardly on body12.

Body12further includes a substantially cylindrical outer wall28extending down from outer periphery20of top wall18and concentric with inner wall24. Outer wall28has an array of internal threads30facing inwardly thereon, as shown inFIGS. 1 and 7. Outer wall28also has a plurality of ridges31aligned substantially parallel to the axis of substantially cylindrical outer wall28. Ridges31are circumferentially spaced from one another around a portion of outer wall28that includes hinge16and circumferentially on both sides of hinge16.

Lid14includes a substantially planar top wall32that has opposed outer and inner surfaces34and36. Inner surface36faces up in the open position of lid14as shown inFIGS. 1-3. However, inner surface36of top wall32faces down and opposes top wall18of body12when lid14is in the closed position ofFIGS. 4-7.

A substantially cylindrical skirt38extends perpendicularly from inner surface36of top wall32and is dimensioned for sealing engagement with sealing surface26of body12when lid14is rotated into the closed position ofFIGS. 4 and 7. Lid14further includes an outer wall42that projects perpendicularly from inner surface36of top wall32at a location spaced outwardly from skirt38. Outer wall42is substantially cylindrically generated about a longitudinal axis that is perpendicular to and spaced from rotational axis “x” of hinge16. Additionally, outer wall42defines an inside diameter that exceeds the outside diameter defined by top wall18and outer wall28of body12. Thus, outer wall42of lid14can be telescoped partly over body12. Outer wall42includes a shield44that extends through an arc on a side of outer wall42substantially opposite hinge16. Shield44of outer wall42preferably extends through an arc of between about 135° and about 320°. Portions of outer wall42that extend beyond shield44have a reduced height to facilitate opening and closing and to avoid interference with body12. In the illustrated embodiment, shield44of outer wall42extends through an arc of approximately 180° at a maximum height. In the preferred embodiment, shield44of outer wall42defines a height of between approximately 0.4-0.7 inch, and preferably about 0.54 inch. Outer wall42further includes a short section46that slopes arcuately from opposite circumferential ends of shield44and continues at a short height through hinge16. Short section46of outer wall42is spaced slightly above ridges31on outer wall28of body12. Thus, ridges31will not impede closure of lid14. The height reduction achieved through short section46of outer wall42permits lid14to be rotated efficiently from the open position ofFIGS. 1-3to the closed position ofFIGS. 4-7without interference with body12.

Lid14further includes parallel circumferentially extending ribs50that extend outwardly from shield44. Ribs50are disposed at locations on lid14spaced circumferentially from hinge16and are substantially symmetrical with a center line “c” that passes perpendicularly through rotational axis “x” at the center of hinge16. Additionally, each rib50extends through an arc of between approximately 90° and 180°, and preferably an arc of about 135°. Thus, ribs50extend along a major circumferential portion of shield44. Ribs50are substantially perpendicular to ridges31when lid14is closed, as shown inFIG. 5.

Cap10can be employed with a laboratory vessel, such as tube60illustrated inFIGS. 8 and 9. Tube60has a cylindrical side wall62, a closed conically generated bottom wall64and an open top (not shown). Portions of side wall62adjacent the open top have an array of external threads dimensioned and configured for threaded engagement with internal threads30on body12of cap10. Ridge31on outer wall28facilitate threaded mounting of body12onto tube60. In this mounted condition, outer wall28of body12surrounds portions of cylindrical side wall62of tube60adjacent the open top of tube60. Additionally, top wall18of body12rests on the open top of tube60and inner wall24of body12telescopes into cylindrical side wall62at the open top of tube60. Lid14can be maintained in the closed condition illustrated inFIG. 8for securely sealing the interior of tube60and maintaining sterility for the interior of tube60and any cell or tissue cultures stored therein. In this closed condition, inner surface36of top wall32of lid14engages against top wall18of body10. Additionally, skirt38is telescoped into sealing engagement with sealing surface26defined by opening22in top wall18and inner wall24. Furthermore, outer wall42of lid14surrounds outer wall28of body12.

The contents of tube60may have to be accessed periodically by a pipette or the like to either remove culture from tube60or to deposit additional growth medium into tube60. For this purpose, a laboratory worker grips side wall62of tube60between the forefingers and palm of a hand so that the thumb of that hand faces upwardly toward cap10. The thumb then is urged against ribs50and lid14is pushed up and away from body12. As a result, lid14begins to rotate about hinge16and out of engagement with body12. The over-center design of hinge16initially will resist rotation of lid14from the closed position shown inFIG. 8. However, the over-center design of hinge16then assists rotation beyond about 90°, and accelerates lid14into the fully open condition illustrated inFIG. 9.

Ribs50extend into positions that are offset relative to centerline “c” passing centrally through hinge16perpendicular to rotation axis “x”. Additionally, the left or right thumb used to open lid14inherently will be in an offset position and is not likely to pass directly over opening22in top wall18of body12. Additionally, ribs50are on the outer surface of shield44. Accordingly, shield44will separate the thumb of the user from opening22in top wall18and from skirt38as the thumb moves for rotating lid14from the closed position ofFIG. 8to the open position ofFIG. 9. Accordingly, the disposition of ribs50and the disposition of shield44cooperate to prevent digital contact with areas of body12near opening22and hence prevent contamination. Additionally, cap10remains securely connected to tube60in both the open and closed conditions of lid14. Accordingly, there is no risk of a cap being placed improperly on a work surface while the contents of tube60are being accessed. Still further, cap10permits convenient one-handed opening and closing and allows the laboratory worker to use the other hand for manipulating a pipette or other access device.

Lid14can be rotated from the open position inFIG. 9back to the closed position ofFIG. 8after the interior of tube60is accessed. The shortening of outer wall42along sections46nearer hinge16enables lid14to be rotated into the closed position without interference with any part of body12. Furthermore, the user inherently will engage portions of ribs50near outer surface34of top wall32for moving lid14to the closed position ofFIG. 8. Hence, contamination with opening22is prevented during closing.

An alternate cap in accordance with the subject invention is identified generally by the numeral10ainFIGS. 10-15. Cap10aincludes a body12aand a lid14athat are joined unitarily by a living hinge16a. The body12aand the living hinge16aare substantially identical to the body12and the living hinge16of the embodiment shown inFIGS. 1-9. More particularly, body12aincludes a generally planar top wall18awith a circular outer periphery20aand a circular opening22aconcentric with outer periphery20a. A short cylindrical inner wall24aextends down from top wall18aconcentrically with circular opening22ain top wall18a. Thus, circular opening22aand inner wall24adefine a short cylindrical sealing surface26afacing inwardly on body12a.

Body12afurther includes a substantially cylindrical outer wall28aextending down from outer periphery20aof top wall18aand concentric with inner wall24a. Outer wall28ahas an array of internal threads30a, as shown inFIGS. 10 and 12.

Lid14aincludes a substantially planar top wall32athat is joined unitarily to top wall18aof body12aby hinge16a. Thus, top wall32aof lid14acan be rotated about a rotational axis “x” defined by hinge16aand relative to top wall18aof body12a. Top wall32aof lid14ahas opposed outer and inner surfaces34aand36a. Inner surface36afaces up in the open position of lid14aas shown inFIGS. 10-13. However, inner surface36aof top wall32afaces down and opposes top wall18aof body12awhen lid14ais in the closed position ofFIGS. 14 and 15.

A substantially cylindrical skirt38aextends perpendicularly from inner surface36aof top wall32aand is dimensioned for sealing engagement with sealing surface26aof body12awhen lid14ais rotated into the closed position ofFIGS. 14 and 15. A plurality of anti-splash notches40aare formed in the outer circumferential surface of skirt38aalong a side of skirt38asubstantially opposite hinge16a. Notches40aextend from the edge of skirt38aspaced from top wall32abut terminate at locations spaced from inner surface36aof top wall32a. Anti-splash notches40apermit a flow of gas during early stages of movement of lid14afrom the closed position ofFIGS. 13 and 14towards the open position ofFIGS. 9-12to balance air pressure on opposite sides of cap10aand to avoid a splashing or spraying of liquid that could otherwise occur with a very rapid change of air pressure. However, anti-splash notches40aare not always required and may not be present on some embodiments.

Lid14afurther includes an outer wall42athat projects perpendicularly from inner surface36aof top wall32aat a location spaced outwardly from skirt38a. Outer wall42ais substantially cylindrically generated about a longitudinal axis that is perpendicular to and spaced from rotational axis “x” of hinge16a. Additionally, outer wall42adefines an inside diameter that exceeds the outside diameter defined by top wall18aand outer wall28aof body12a. Thus, outer wall42aof lid14acan be telescoped partly over body12a. Outer wall42aincludes a shield44athat extends through an arc on a side of outer wall42asubstantially opposite hinge16a. Shield44aof outer wall42apreferably extends through an arc comparable to the circumferential extend of shield44described above. Outer wall42afurther includes short sections46athat extend from opposite circumferential ends of shield44atowards hinge16a. The height reduction achieved through short sections46aof outer wall42apermit lid14ato be rotated efficiently from the open position ofFIGS. 10-13to the closed position ofFIGS. 14 and 15without interference with body12a.

Lid14afurther includes tabs50aand52athat extend outwardly from shield44asubstantially in the plane defined by top wall32aof lid14a. Tabs50aand52aare disposed at locations on lid14aspaced circumferentially from hinge16a. More particularly, each tab50,52extends from a side location spaced circumferentially approximately 90° from a center line “c” that passes perpendicularly through rotational axis “x” at the center of hinge16a. Additionally, tabs50aand52aextend towards a distal location on top wall32asubstantially diametrically opposite the intersection of center line “c” and rotational axis “x” of hinge16a.

Each tab50aand52ahas a shape substantially conforming to an isosceles right triangle that has a rounded right angle corner and a concave hypotenuse conforming to the outer circumferential surface of shield44a. The maximum radial extent of each tab50aand52ais disposed at a position spaced approximately 135° from the intersection of center line “c” and rotational axis “x” of hinge16a. The maximum extent of tabs50a,52afrom shield44ais sufficient to provide a secure and convenient engagement surface for a thumb or forefinger during opening of lid14arelative to body12a. Preferably the maximum extent of tabs50aand52ais in a range of 0.2-0.4 inch. One or more tabs can be disposed at other locations on lid14aand the tabs can take other configurations. For example, tabs50aand52acan be diametrically opposite and may extend normal to center line “c”.

Cap10acan be employed with a laboratory vessel, such as tube60as described above and illustrated inFIGS. 8 and 9. More particularly, a laboratory worker may grip side wall62of tube60between the forefingers and palm of a hand so that the thumb of that hand faces upwardly toward cap10. The thumb then is urged against tab50aor52aand lid14ais pushed up and away from body12a. As a result, lid14abegins to rotate about hinge16aand out of engagement with body12a. Notches40amove past sealing surface26aof body12aduring the initial movement of lid14ato balance pressure on opposite sides of cap10aand to avoid splashing or spraying that could otherwise occur with a sudden change of pressure. The over-center design of hinge16ainitially will resist rotation of lid14afrom the closed position shown inFIGS. 14 and 15. However, the over-center design of hinge16athen assists rotation beyond about 90°, and accelerates lid14ainto the fully open condition illustrated inFIGS. 10-13.

Tabs50aand52aare in offset positions relative to centerline “c” passing centrally through hinge16aperpendicular to rotation axis “x”. Hence, the thumb used to open lid14anecessarily will be in an offset position and is not likely to pass directly over opening22ain top wall18aof body12a. Additionally, tabs50aand52aare spaced outwardly from shield44a. Accordingly, shield44awill separate the thumb of the user from opening22ain top wall18aand from skirt38aas the thumb moves for rotating lid14afrom the closed position ofFIGS. 14 and 15to the open position ofFIGS. 10 and 13. Accordingly, the disposition of tabs50aand52aand the disposition of shield44acooperate to prevent digital contact with areas of body12anear opening22aand hence prevent contamination. Additionally, cap10aremains securely connected to tube60ain both the open and closed conditions of lid14a. Accordingly, there is no risk of a cap being placed improperly on a work surface while the contents of tube60aare being accessed. Still further, cap10apermits convenient one-handed opening and closing and allows the laboratory worker to use the other hand for manipulating a pipette or other access device.

The invention has been described with respect to a preferred embodiment. However, changes can be made without departing from the scope of the invention defined by the appended claims. For example, the lid may be formed unitarily with the tube or other such vessel. This design option will avoid the need for providing a cap with a body that is hingedly attached to the tube or other vessel.

The lid14can have surface configurations other than ribs50and tabs50a,52a. For example, dimples, bumps, recesses or general roughening can be provided.

The lid14can be provided with only one of the tabs50aand52a.

The ribs50or tabs50aand52acan extend into even more offset disposition and spaced further from the center line “c” passing perpendicularly through the rotational axis “x” defined by the hinge16.

The hinge16need not be a living hinge and need not be of over-center design. For example, a hinge with plural parts snapped or otherwise connected can be provided.