Assembly of a protected stopper and a test tube, said stopper being used for blood sample collecting or biological liquids handling test tubes

Abstract

An assembly of a protected stopper with a test tube consists of a protected stopper for blood sample collecting or biological liquids handling test tubes which contains a substantially cylindrical inner body made of an elastomer, the body including a lower portion for insertion in a test tube, an upper abutment flange, and an abutment step formed between the inner body lower portion and the upper flange. The stopper also includes a substantially cylindrical cover made of a plastic for enclosing an upper part of the test tube and the inner body, the cylindrical cover including a free upper region for insertion of a sampling needle in the stopper and arc-like openings provided in the upper part. The engaging means provided in the cylindrical cover for engaging the inner body are constituted by arc-like protrusions which protrude from the inner wall of cylindrical cover which surrounds the lower portion of the inner body and couple with the abutment step, the protrusions being in an angular position which corresponds to the arc-like openings, a plan area of each one of the protrusions being entirely contained within a plan area of corresponding ones of the openings. The thickness of the cylindrical cover should preferably be 0.055-5.5 mm.

Description

[0001] This application is a Continuation-in-part of U.S. Ser. No. 09/339,861 filed Jun. 25, 1999

FIELD OF THE INVENTION

[0002] The present invention relates to a protected stopper for blood sample collecting or biological liquids handling test-tubes.

BACKGROUND OF THE PRIOR ART

[0003] Protected stoppers for blood sample collecting or biological liquids handling test-tubes are already known. They are mainly composed of two parts:

[0004] an inner body made of rubber, which closes the test-tube and is adapted to be pierced with the needle of the syringe used to take the blood sample and/or with the needle of the syringe used for the subsequent sampling required to perform a laboratory test;

[0005] a cover made of compact plastics, which encloses the rim of the test-tube and the rubber body, performing a protective function for the person handling the tube.

[0006] The compact cover is stably anchored to the inner body and defines, in combination with said inner body in the region to be pierced with the needle, a chamber for depositing any blood droplets leaking from the needle, so as to protect the operator by preventing him from making contact with it.

[0007] Several methods for anchoring one another said inner rubber body and the compact external cover are known.

[0008] In a first embodiment, the upper part of the cover corresponding to the region where the needle is inserted is fully open, but for a small circumferential protrusion.

[0009] The internal body is provided with an external abutment step for a circumferential protrusion provided on the inner wall of the cover.

[0010] Assembly is performed by inserting the inner body in the cover, by elastic deformation, through the open upper part and by then placing a retention ring made of compact plastics between the small protrusion of the cover and the inner rubber body.

[0011] In this case, the stopper is formed by three parts (two main ones and one for mutually anchoring them); this entails the disadvantage that assembly must be performed with two separate operations.

[0012] In a second constructive embodiment disclosed in EP 129,029, the stopper is actually made of two parts and the protective cover is internally provided, in the wall that faces the inner body, with an annular groove in which a corresponding annular protrusion which protrudes from the internal rubber body is fitted.

[0013] From the point of view of production, the annular groove of the compact cover defines an undercut which causes problems upon extraction from the injection mold from which it is obtained.

[0014] In fact the extraction of the core of the mold, which forms the inner hollow region and the annular groove, occurs by deforming the edge of the annular groove and must be performed, in order to obtain an acceptable product, when the plastic material is still soft, i.e., before hardening has occurred completely, and the thickness of the wall in which the groove is formed must be sufficient to deform and return to the intended shape, after extraction from the mold.

[0015] This thickness of the wall causes a diametrical bulk which considerably increases the corresponding diametrical dimensions of the test-tube.

[0016] The diametrical dimensions of the annular protrusion of the inner body also prevent mutual contact between the test-tube and the cover, leaving an empty space.

[0017] All this is constrained by the fact that the difference between the overall diameter of the stopper and the diameter of the test-tube must not be excessive, on penalty of making it impossible to insert said test-tube, when closed (assembled to the stopper), in corresponding seats provided in sampling accessories or adapters for analysis equipment, such as centrifuges.

[0018] The difference in diameter required in order to obtain a thickness of the cover which is sufficient to allow to remove said cover from the mold increases with the diameter of the test-tube; accordingly, for example, for test-tubes having a diameter of 16 mm it has not been possible to provide a stopper according to the configuration shown in EP 129,029 which could be accepted by the above mentioned laboratory equipment.

SUMMARY OF THE INVENTION

[0019] The object of the present invention is to provide an assembly of a protected stopper and a test tube. The protected stopper for blood sample collecting or biological liquids handling test-tubes is composed of only two parts, an inner body made of elastomer and an external cover made of compact plastics, the external wall of the cover may be thin, that is slightly exceeding the dimensions of the test-tube, but this is not essential.

[0020] Another object is to provide a protected stopper in which the current production problems in terms of extraction of the cover from the mold after injection have been eliminated.

[0021] A further object is to provide a protected stopper in which the compact plastic cover is always in contact with the upper part of the test-tube.

[0022] Still a further object is to provide a protected stopper which can be manufactured at a lower cost with respect to conventional stoppers.

[0023] These objects and others which will become apparent hereinafter are achieved by a protected stopper for blood sample collecting or biological liquids handling test-tubes, comprising:

[0024] a substantially cylindrical inner body made of an elastomer, with a lower portion adapted for insertion in a test-tube and an upper abutment flange;

[0025] a substantially cylindrical cover made of compact plastics, which is adapted to enclose the upper part of said test-tube and said inner body, leaving free an upper region for inserting the sampling needle;

[0026] said cover having means for engaging said inner body;

[0027] said stopper being characterized in that the engagement means are constituted by arc-like protrusions which protrude from the wall of the cover that surrounds said lower portion of said inner body and couple to the abutment step defined between said inner body and said upper flange. The protrusions are in an angular position which corresponds to arc-like openings provided in the upper part of the cover, the plan area of each one of the protrusions being entirely contained within the plan area of the corresponding one of said openings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further characteristics and advantages of the invention will become apparent from the detailed description of a preferred embodiment thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein:

[0029] FIG. 1 is an exploded perspective view of a test-tube related to the protected stopper;

[0030] FIG. 2 is a sectional perspective view, taken along a longitudinal plane, of the assembly of FIG. 1, in the assembled condition:

[0031] FIG. 3 is a sectional view of the assembly of FIG. 1, in the assembled condition;

[0032] FIG. 4 is a perspective view of the two components of the protected stopper, taken along a sectional plane so as to clearly illustrate their constructive details;

[0033] FIG. 5 is a top plan view of one of the two components of the protected stopper, particularly the cover;

[0034] FIG. 6 is a sectional view of another embodiment of the stopper.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] With reference to FIGS. 1-5, this invention covers an assembly of a protected stopper and a test tube. The protected stopper for blood sample collecting or biological liquids handling test tubes comprises a substantially cylindrical inner body (10) made of an elastomer. The body includes an upper flange (13) and a lower portion (11) for insertion in a test tube (12). The test tube (12) has an upper part. The body includes an abutment step (14) formed between the inner body lower portion and the upper flange (13). The stopper also comprises a substantially cylindrical cover (15) for enclosing the upper part of the test tube and the inner lower body (10). The cylindrical cover (15) has an upper part (18) and includes a free upper region (16) for insertion of a sampling needle in the stopper. Arc-like openings (19) are provided in the upper part of the cover. The means for engaging the inner body are constituted by arc-like protrusions (17) which protrude from an inner wall of the cylindrical cover which surrounds the lower portion of the inner body and couples to the abutment step (14). The protrusions are in an angular position which corresponds to the arc-like openings (19). A plan area of each one the protrusions is entirely contained within a plan area of corresponding ones of the openings (19) so that the protrusions and the arc-like openings are vertically aligned. The protrusions are free of undercuts and have a radial dimension substantially equal to the thickness of a test tube (12) which has an edge so that when the stopper is assembled to the test tube, the protrusions are interposed between the abutment step (14) and the edge of said tube.

[0036] The axial dimension of the flange 13 is of course substantially identical to the distance between the protrusions 17 and the upper part 18 of the cover 15.

[0037] As already stated hereinabove, the protrusions 17 are in an angular position that corresponds to arc-like openings 19 provided in the upper part 18 of the cover 15, and the plan area of each one of the protrusions 17 is entirely contained within the plan area of the corresponding opening 19. In this manner the arc-like protrusions 17 do not constitute for the mold used for manufacturing, undercuts which might cause problems in extraction after molding.

[0038] It should also be observed that the inner body 10 is provided, in an upward region, with a recess 21 whose diameter is smaller than the diameter of the circular opening 16, so that it defines, on its own, a chamber for collecting any drops of blood or of biological liquids that might fall from the sampling needle.

[0039] With reference to FIG. 6 which covers another embodiment, this figure shows an assembly of a protected stopper with a test tube, the stopper for blood sample collecting or biological liquids handling test tubes. The stopper comprises a substantially cylindrical inner body (10a), made of an elastomer. The body includes an upper flange (13a) and a lower portion (11a) for insertion in a test tube (12). The test tube (12) has an upper part. The upper abutment flange (13a) rests on the upper part of the test tubes. The stopper also comprises an abutment step (14a) and a substantially cylindrical cover (15) for enclosing the upper part of the test tube and the inner lower body (10a). The cylindrical cover has an upper part (18), including a free upper region (16) for insertion of a sampling needle in the stopper. Arc-like openings (19) are provided in the upper part of the cover. Engaging means are provided in the cylindrical cover for engaging the inner body, which engaging means are constituted by arc-like protrusions (17a) which have a triangular cross-section and which protrude from an inner wall of the cylindrical cover which surrounds the lower portion of the inner body and couples with the abutment flange (13a). The protrusions (17a) are free of undercuts. The abutment step (14a) of the inner body (10a) has radial dimensions such as to cause the rim region of the test tube (12) and the arc-like protrusions (17a) to abut thereagainst, the protrusions being external with respect to said rim region and have an upper part located with respect to an upper part of the cover at a distance which is substantially equal to an axial extension of the flange (13a) of the inner body, wherein the arc-like protrusions have a rectangular cross-section extension, so as to form a ledge.

[0040] This embodiment is provided by choosing appropriate dimensions for the diameters of the different components.

[0041] As regards operation, as already mentioned, the inner body 10 is assembled to the cover 15 by inserting it from the lower part until the flange 13 moves beyond the protrusions 17 and fits in the region between the protrusions and the upper part 18.

[0042] It is then possible to insert the rim of the test-tube 12, which places itself between the cover 15 and the lower portion 12 of the body 10.

[0043] In practice it has been found that the intended objects of the present invention have been achieved.

[0044] In fact the cover 15 has no hollows in its cylindrical wall; it has protrusions instead, and accordingly the only limitations to its thickness are related merely to requirements of mechanical strength in use and no longer to production needs. The thickness of the cylindrical cover may be 0.055-5.5 mm. Thus the test tubes may have a diameter of both 13 mm and also 16 mm.

[0045] Accordingly, its thickness can be minimal and therefore the total diametrical space occupation of the test-tube with the cover assembled thereon can be minimal too. Thus the test-tubes may have a diameter of 13 mm and also 16 mm.

[0046] The structure of the cover 15 makes it possible that the protrusions 17 are in any case not a problem for the molding operation.

[0047] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept.

[0048] All the details may further be replaced with other technically equivalent elements.

[0049] In practice, the materials used, so long as they are compatible with the contingent use, as well as the dimensions, may be any according to requirements.

[0050] The disclosures in Italian Patent Application No. PD98A000167 from which this application claims priority are incorporated herein by reference.

Claims

1. An assembly of a protected stopper and a test tube, said protected stopper for blood sample collecting or biological liquids handling test tubes comprising a substantially cylindrical inner body (10) made of an elastomer, said body including an upper flange (13) and a lower portion (11) for insertion in a test tube (12), said test tube (12) having an upper part, an upper abutment flange (13), said body including an abutment step (14) formed between said inner body lower portion and said upper flange (13), said stopper also comprising a substantially cylindrical cover (15) for enclosing said upper part of said test tube and said inner lower body (10), said cylindrical cover (15) having an upper part (18) and including a free upper region 16) for insertion of a sampling needle in said stopper, and arc-like openings (19) provided in the upper part of said cover, means for engaging said inner body, said engaging means being constituted by arc-like protrusions (17) which protrude from an inner wall of said cylindrical cover which surrounds said lower portion of said inner body and couples to said abutment step (14), said protrusions being in an angular position which corresponds to said arc-like openings (19), a plan area of each one of said protrusions being entirely contained within a plan area of corresponding ones of said openings (19), whereby said protrusions and said arc-like openings are respectively vertically aligned, said protrusions being free of undercuts, said protrusions having a radial dimension substantially equal to the thickness of a test tube (12), said test tube having an edge, whereby when the stopper is assembled to said test tube, said protrusions are interposed between abutment step (14) and said edge of said test tube.

2. The stopper assembly according to

claim 1 wherein said cover is always in contact with the test tube.

3. The stopper assembly according to

claim 1 wherein the axial dimension of said flange (13) is identical to the distance between said protrusions (17) and the upper part (18) of said cover.

4. The assembly according to

claim 1 wherein said cylindrical cover (15) has a thickness of 0.055-5.5 mm and is capable of operation with test tubes of external diameter 5-16 mm.

5. An assembly of a protected stopper with a test tube, said stopper for blood sample collecting or biological liquids handling test tubes, comprising a substantially cylindrical inner body (10a), made of an elastomer, said body including an upper flange (13a) and a lower portion (11a) for insertion in a test tube (12), said test tube (12) having an upper part, said upper abutment flange (13a) resting on said upper part of said test tubes, said stopper also comprising a substantially cylindrical cover (15) for enclosing said upper part of said test tube and said inner lower body (10a), said cylindrical cover having an upper part (18), including a free upper region (16) for insertion of a sampling needle in said stopper, and arc-like opening (19) provided in the upper part of said cover, engaging means provided in said cylindrical cover for engaging said inner body, said engaging means being constituted by arc-like protrusions (17a) which have a triangular cross-section and which protrude from an inner wall of said cylindrical cover which surrounds said lower portion of said inner body and couples with said abutment, said protrusions (17a) being free of undercuts, wherein said abutment step (14a) of said inner body (10a) has radial dimensions such as to cause the rim region of said test tube (12) and said arc-like protrusions (17a) to abut thereagainst, said protrusions being external with respect to said rim region, wherein said protrusions (17a) have an upper part located with respect to an upper part of said cover at a distance which is substantially equal to an axial extension of said flange (13a) of said inner body, wherein said arc-like protrusions have a rectangular cross-section extension, so as to form a ledge.

6. The assembly according to

claim 5 wherein said cylindrical cover (15) has a thickness of 0.055-5.5 mm and is capable of operation with test tubes of external diameter 5-16 mm.