Needle type safety connector

Abstract

A safety needle connector according to the invention comprises a hollow needle through which fluid may pass fastened to a needle support sleeve itself connected to a fluid tube. The needle support sleeve may be connected by clipping it axially into a receiving structure of a protective cylinder that surrounds a projecting needle portion. The receiving structure comprises receiving cylinders in which the needle support sleeve is engaged and comprising locking tongues that cooperate with a bearing flange to allow penetration of the needle support sleeve and prevent its withdrawal. A closure sleeve is engaged around the projecting needle portion to form a sealed connection in the needle passage.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to safety connectors for connecting a sampling container to a fluid tube. The invention relates in particular to connectors of the above kind for taking blood samples in applications in the health field.

When taking blood samples, in particular for blood donations, the blood must be systematically analyzed by taking a small sample of blood in a sampling container. To this end, a fluid tube must be removably connected and sealed to a sampling container under conditions of absolute hygiene, necessitating minimum movement of the operator to connect the sampling container to the tube and to disconnect it therefrom.

At the same time, the operator must be protected against all risks of injury and contamination by the blood sample.

To this end, there has already been designed a safety needle connector as described in the document U.S. Pat. No. 4,784,650, comprising a hollow needle through which fluid can pass, a needle support sleeve and a protective cylinder. The needle support sleeve carries the needle and connects it and seals it to the fluid tube to which it is fixed. A protruding needle portion axially extends the needle support sleeve at the end opposite the fluid tube. The protective cylinder defines an interior space containing the projecting needle portion, with an open distal end for inserting the sampling container to be connected by the needle and a closed proximal end for connection to the needle support sleeve.

In practice, it is necessary to produce the needle support sleeve and the protective cylinder as separate components, in order to be able to use different components having satisfactory properties in respect of clipping, on the one hand, and firm retention of the needle in the needle support sleeve, on the other hand.

To this end, the prior art devices comprise a safety connector in two main parts designed to be assembled together, namely a needle support sleeve and a protective cylinder, with connecting means for clipping the protective cylinder to the needle support sleeve.

The connecting means comprise a large-diameter proximal cylinder with a proximal opening followed by a smaller diameter distal cylinder whose bottom communicates with the interior of the protective cylinder via a needle passage. Retaining means are provided for axially retaining the needle support sleeve engaged in the proximal cylinder and in the distal cylinder.

In the prior art devices, the retaining means comprise clipping holes in the lateral wall of the distal cylinder in which engage protuberances on the needle support sleeve.

The prior art needle type safety connectors have drawbacks that affect their safety in use. In particular, the resistance to tearing out of the needle is poor; sometimes drops of blood may flow out of the sampling phial during the movement of withdrawing the phial, and these drops of blood may flow through the clipping holes in the proximal cylinder; there is also a non-negligible risk of permanent deformation of the distal cylinder when the needle support sleeve is pushed into the distal cylinder and the proximal cylinder; this kind of permanent deformation further increases the risks of a defective seal and of blood flowing out of the protective cylinder; because of the small axial clipping travel, it is also difficult to control the clipping of the protective cylinder onto the needle support sleeve.

SUMMARY OF THE INVENTION

The problem addressed by the present invention is that of designing a new safety needle connector structure that is easy to assemble to the needle support tube by simple clipping, that is sealed, that may be closed for safety after use, and that retains the needle sufficiently to prevent any movement caused by the axial force of pushing in the sampling phial.

To achieve the above and other objects, the invention proposes a safety needle connector comprising a hollow needle through which fluid can pass, a needle support sleeve, and a protective cylinder, the needle support sleeve carrying the needle and connecting it and sealing it to a fluid tube to which it is fixed, a projecting needle portion axially extending the needle support sleeve at the end opposite the fluid tube, the protective cylinder having an interior space containing the projecting needle portion, with an open distal end for inserting a sampling container to be connected by the needle, and with a closed proximal end with connection means for connecting it to the needle support sleeve; the connection means comprising a proximal cylinder with a large diameter and a proximal opening followed by a distal cylinder with a smaller diameter whose bottom communicates with the interior space of the protective cylinder via a needle passage and comprising retaining means for axially retaining the needle support sleeve engaged in the proximal cylinder and in the distal cylinder; according to the invention:

• • the lateral walls of the proximal cylinder and the distal cylinder are fluid-tight,
  • the needle support sleeve comprises a bearing flange conformed to penetrate with appropriate peripheral clearance into the proximal cylinder and to abut against an intermediate shoulder connecting the proximal cylinder and the distal cylinder,
  • the proximal cylinder comprises elastically flexible locking tongue means which when at rest, and starting from an intermediate region of the protective cylinder, are oriented in an oblique direction toward the proximal end to bear against the distal face of the bearing flange, and then, following flexing in the downstream direction of the locking tongue means upon penetration of the needle support sleeve, to bear against the proximal face of the bearing flange, thereby opposing withdrawal of the needle support sleeve from the protective cylinder.

In one advantageous embodiment of the invention the locking tongue means comprise two diametrically opposite tongues.

To provide an effective seal for the needle after removing the sampling phial, a closure sleeve is engaged around the projecting needle portion and passes through the needle passage in the bottom of the distal cylinder to provide a seal between the needle and the bottom of the distal cylinder. Simultaneously, the sleeve retracted by virtue of elastic deformation in the axial direction when the phial is engaged around the needle, and is axially deployed again around the needle to close off its distal orifice upon withdrawal of the sampling phial.

In practice, the needle support sleeve comprises a sealing flange, offset in the upstream direction from the bearing flange, and bearing against the locking tongue means when the needle support sleeve is engaged in the protective cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention will emerge from the following description of particular embodiments of the invention, which is given with reference to the appended drawings, in which

FIG. 1 is a diagrammatic general view of a blood sampling system using a safety needle connector of the present invention;

FIG. 2 is a partial detail view to a larger scale and in longitudinal section of one embodiment of a safety needle connector of the invention, prior to assembly;

FIG. 3 is a view to a larger scale of the safety connector from FIG. 1 in longitudinal section taken along the line A-A in FIG. 4 and in the assembled state; and

FIG. 4 is an end view of the FIG. 3 safety connector.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows the general structure of a blood sampling device using a safety connector of the present invention.

From a blood source 1 shown diagrammatically, for example a catheter inserted into the venous system of a patient, tubes convey blood either to a series of sachets 2, 3 and 4 or to a test sampling assembly 5, according to the settings of valves 6 and 7 controlled by the operator.

The test sampling assembly 5 comprises a buffer sachet 19 in series in a fluid tube 8, for example. The end of the fluid tube 8 carries the safety needle connector 9 of the invention.

The safety needle connector 9 comprises a hollow needle 10 through which fluid can pass, a needle sleeve 11, and a protective cylinder 12. The needle support sleeve 11 is fixed to the end of the fluid tube 8 and carries the needle 10, which it connects and seals to the fluid tube 8. The needle 10 has a projecting needle portion 10a at the end opposite the fluid tube 8 that extends the needle support sleeve 11 axially.

The protective cylinder 12 defines an interior space 12a whose shape is adapted to contain the whole of the projecting needle portion 10a to prevent any contact of an operator's hand with the sharp end portion 10c of the needle 10. The protective cylinder 12 further comprises an open distal end 12b for inserting a sampling container 13 to be connected to the fluid tube 8. The distal end 12b may be closed off by a seal 14 adapted to be folded over. In a manner that is known in the art, the sampling container 13 comprises a stopper 13a made from a material that may be pierced by the projecting needle portion 10a, and the shape of the sampling container 13 is adapted to fit into the interior space 12a of the protective cylinder 12. On applying pressure 13b to push the sampling container 13 axially in the direction of the needle 10, the stopper 13a is pierced by the needle 10, which establishes communication between the interior of the sampling container 13 and the fluid tube 8 to introduce an appropriate quantity of blood into the sampling container 13, which may then simply be extracted axially from the protective cylinder 12: the stopper 13a closing elastically on itself to seal the sampling container 13.

Consider now the details of the structure of the safety connector 9, as shown in FIGS. 2 to 4.

These figures show again the needle support sleeve 11, the needle 10 and the protective cylinder 12.

The protective cylinder 12 has a closed proximal end 12c with means for connecting it to the needle support sleeve 11. The connecting means are adapted to enable the protective cylinder 12 and the needle support sleeve 11 to be assembled together by clipping them together by virtue of a simple movement in axial translation 11e toward each other. At the same time, the same movement in axial translation 11e toward each other makes a seal that makes it impossible for blood to flow from the interior space 12a of the protective cylinder 12 onto its exterior surface and onto the needle support sleeve 11.

The connecting means for the protective cylinder 12 comprise a proximal cylinder 12d having an inside diameter D_d larger than the diameter of the needle support sleeve 11. The proximal cylinder 12d is followed by a distal cylinder 12e with a smaller inside diameter D_e, with an intermediate shoulder 12f which connects the proximal cylinder 12d and the distal cylinder 12e.

The distal cylinder 12e terminates at a bottom 12g that communicates with the interior space 12a of the protective cylinder 12 via a small diameter needle passage 12h.

The lateral walls of the proximal cylinder 12d and the distal cylinder 12e are fluid-tight, i.e. comprise no openings that would allow a fluid such as blood to pass through them.

The needle support sleeve 11 comprises a bearing flange 11a shaped to penetrate into the proximal cylinder 12d and to abut against the intermediate shoulder 12f when the needle support sleeve 11 is engaged on the protective cylinder 12 in the assembly position, as shown in FIG. 3.

The proximal cylinder 12d comprises elastically flexible locking tongue means, for example two diametrically opposite tongues 12i and 12j, that cooperate with the bearing flange 11a to provide the clipping means opposing separation of the needle support sleeve 11 and the protective cylinder 12 when they are assembled together.

To this end, when at rest, the elastically flexible locking tongues 12i and 12j are, starting from an intermediate region of the proximal cylinder 12d, oriented obliquely toward the proximal end 12k of the proximal cylinder 12d, as may be seen in FIG. 2, and their free ends are at a distance from each other less than the diameter of the bearing flange 11a. As a result, when the needle support sleeve 11 is moved toward the protective cylinder 12, the bearing flange 11a bears on the free ends of the locking tongues 12i and 12j, pushing them back toward the shoulder 12f. The locking tongues 12i and 12j then flex until they assume an opposite oblique orientation toward the shoulder 12f, as may be seen in FIG. 3.

Because an appropriate peripheral clearance is provided between the bearing flange 11a and the peripheral wall of the proximal cylinder 12d, or because of the elasticity of the material constituting the proximal cylinder 12d, which is able to spread slightly when the bearing flange 11a passes between the locking tongues 12i and 12j, the bearing flange 11a may continue its travel until it abuts against the intermediate shoulder 12f, the locking tongues 12i and 12j then bearing against the proximal face of the bearing flange 11a, as may be seen in FIG. 3. In this position, the locking tongues 12i and 12j also bear on the adjacent cylindrical portion 11b of the needle support sleeve 11, this cylindrical portion 11b having a diameter that is sufficient to maintain the locking tongues 12i and 12j oriented obliquely toward the shoulder 12f. The locking tongues 12i and 12j then oppose withdrawal of the needle support sleeve 11 from the protective cylinder 12.

In the embodiment shown in FIGS. 1, 3 and 4, a closure seal 15 is fitted around the protecting needle portion 10a and passes through the needle passage 12h in the bottom 12g of the distal cylinder 12e, providing the seal between the needle 10 and the bottom 12g of the distal cylinder 12e. The closure sleeve 15 is simultaneously made from an elastically retractable material and closes the free end 10c of the needle 10 when there is no sampling phial 13 engaged over the needle 10.

In the assembled position shown in FIG. 3, a proximal end portion 15a of the closure sleeve 15 is compressed axially between the distal end 11c of the needle support sleeve 11 and the bottom 12g of the distal cylinder 12e. This improves the seal.

In the embodiment shown in FIGS. 1 and 3, the needle support sleeve 11 further comprises a sealing flange 11d offset in the upstream direction from the bearing flange 11a and adapted to bear against the locking tongues 12i and 12j when the needle support sleeve 11 is engaged in the protective cylinder 12.

The protective cylinder 12 may advantageously be molded from a first plastic material such as polypropylene.

Simultaneously, the needle support sleeve 11 may be molded from a second plastic material such as polycarbonate.

The closure sleeve 15 is advantageously made from a closed cell resilient foam or an elastically flexible elastomer such as latex.

The present invention is not limited to the embodiments that have been explicitly described and includes variants and generalizations thereof within the scope of the following claims.

Claims

1. A safety needle connector comprising a hollow needle through which fluid can pass, a needle support sleeve, and a protective cylinder, the needle support sleeve carrying the needle and connecting it and sealing it to a fluid tube to which it is fixed, a projecting needle portion axially extending the needle support sleeve at the end opposite the fluid tube, the protective cylinder having an interior space containing the projecting needle portion, with an open distal end for inserting a sampling container to be connected by the needle and with a closed proximal end with connection means for connecting it to the needle support sleeve, the connection means comprising a proximal cylinder with a large diameter and a proximal opening followed by a distal cylinder with a smaller diameter whose bottom communicates with the interior space of the protective cylinder via a needle passage and comprising retaining means for axially retaining the needle support sleeve engaged in the proximal cylinder and in the distal cylinder, wherein the lateral walls of the proximal cylinder and the distal cylinder are fluid-tight, the needle support sleeve comprises a bearing flange conformed to penetrate with appropriate peripheral clearance into the proximal cylinder and to abut against an intermediate shoulder connecting the proximal cylinder and the distal cylinder, the proximal cylinder comprises elastically flexible locking tongue means which when at rest, and starting from an intermediate region of the protective cylinder, are oriented in an oblique direction toward the proximal end to bear against the distal face of the bearing flange, and then, following flexing in the downstream direction of the locking tongue means upon penetration of the needle support sleeve, to bear against the proximal face of the bearing flange, thereby opposing withdrawal of the needle support sleeve from the protective cylinder.

2. A safety connector according to claim 1, wherein the locking tongue means comprise two diametrically opposite tongues.

3. A safety connector according to claim 1, wherein a closure sleeve is engaged around the projecting needle portion and passes through the needle passage in the bottom of the distal cylinder to provide a seal between the needle and the bottom of the distal cylinder.

4. A safety connector according to claim 1, wherein the needle support sleeve comprises a sealing flange, offset in the upstream direction from the bearing flange, and bearing against the locking tongue means when the needle support sleeve is engaged in the protective cylinder.

5. A safety connector according to claim 1, wherein the protective cylinder is molded from a first plastic material such as polypropylene.

6. A safety connector according to claim 1, wherein the needle support sleeve is molded from a second plastic material such as polycarbonate.

7. A safety connector according to claim 1, wherein the closure sleeve is made from a closed cell resilient foam or an elastically flexible elastomer such as latex.