MALE LUER LOCK CONNECTOR FOR MEDICAL FLUID LINES.

Description

BUZZI, NO) Aid . ò. ANTONI AND LLI D'OUl.7 DESCRIPTION of the industrial invention entitled: "Male Luer Lock Connector for Medical Fluid Lines" by: Industrie Boria Spa, Italian nationality, Via G. di Vittorio Ibis, 10024 Moncalieri (TO) Designated Inventor: Gianni Guala , z 9 pn A rnn 1 / n Filed on: 02 / 16 / 2001 Z c * * * DESCRIPTION TEXT The present invention relates in general to connectors for medical fluid lines, and more particularly concerns a male luer lock connector of the type comprising an elongated tubular body having a cylindrical external surface portion and an external luer cone terminal portion, and a bushing having an internal thread with which a female luer lock connector can be screwed into which the external luer cone terminal portion of the tubular body is adapted to engage axially. Traditionally, the compass is fixed to the tubular body, being integral with the cylindrical external surface portion of the latter. More recently, solutions have been proposed in which the compass is mounted on the cylindrical external surface portion of the tubular body in a rotatable and sliding for an axial advance stroke of defined length starting from a retracted position. This design has the advantage that the male Luer Lock connector can be coupled and locked with the female Luer Lock connector, and unlocked and uncoupled by the latter, without having to rotate the tubular body, and therefore without deforming and twisting the flexible tubing of the medical line attached on one side to the male connector and on the other side to the female connector. However, these rotating and sliding sleeve solutions present a series of drawbacks. First, there is the risk that inexperienced or distracted operators may incorrectly connect the male and female connectors by simply axially engaging the respective Luer cones without screwing, or at least without fully screwing, the sleeve onto the female connector. This poses the risk of accidental separation between the male and female connectors, with serious consequences for the patient to whom the medical line is applied. A further drawback of the above-mentioned known solutions lies in the relative ease of xino,a '5? O'dV LON Uncouple the male Luer Lock connector from the female connector when fully screwed into the socket, due to the modest effort required to overcome the unscrewing torque. This may also result in unwanted or accidental uncoupling of the male Luer Lock connector from the female connector. The purpose of the present invention is to overcome the aforementioned drawbacks, and to create a male Luer lock connector of the type defined at the beginning, with a rotating and sliding bushing, shaped on one side in such a way as to prevent loose or incorrect coupling of the male connector on the female connector and on the other to prevent accidental uncoupling, by increasing the amount of the initial unscrewing torque of the bushing. According to the invention, these objects are achieved by means of a male Luer lock connector of the type defined in the introductory part of claim 1 and having the combination of features listed in the characterizing part of claim 1 itself. These features are the following: - the axial stroke of the compass has a short length which does not allow for firmly engage said conical terminal portion external luer of the connector body onto said female luer lock connector without at least partially screwing the internal thread of the bushing onto the female luer lock connector, - the cylindrical external surface portion of the tubular body of the connector has an annular enlargement that can be elastically engaged by friction by said bushing following the screwing of the internal thread of the latter onto said female Luer lock connector. Thanks to this solution idea, important advantages are obtained in terms of safety and operational reliability of the connector, summarised in the following. First, mating the male Luer Lock connector to the female Luer Lock connector, through the stable engagement between the respective Luer cones, cannot be achieved without at least partially tightening the threaded sleeve. This prevents an inexperienced or distracted operator from failing to tighten the sleeve, but rather encourages them to tighten it fully following the need for initial tightening. Second, in the screwed condition BUZZI, AND\ of the compass on the female Luer lock connector the interaction between this bushing and the annular enlargement of the cylindrical portion of the body increases the mutual contact surface and therefore the cohesion, ensuring a stable union between the male Luer lock connector and the female Luer lock connector not only when the bushing is fully screwed in, but also when it is only partially screwed in. This effect is further accentuated if, as can be advantageously foreseen by the invention, the aforementioned annular enlargement of the cylindrical portion of the tubular body of the connector has a conical surface diverging towards the said Luer cone terminal portion. Furthermore, the elastic reaction between the bushing and the annular enlargement of the cylindrical portion of the body acts as a brake and also prevents accidental or unwanted unscrewing of the bushing and therefore involuntary disconnections between the male Luer Lock connector and the female Luer Lock connector, thanks to an appreciable increase in the initial unscrewing torque and, therefore, in the effort required to overcome this torque. Ultimately, the male luer lock connector according to the invention presents, in comparison with the similar connectors currently known, qualities of greater safety and reliability. The invention will come Now described in detail with reference to the attached drawings, provided for illustrative purposes only non-limiting, in which : Figure 1 is a schematic perspective view of a Luer connector male lock for lines of medical fluids according to 1st invention, - Figure 2 is a elevated view side of figure 1, the Figure a view in section longitudinal of the figure 2, there Figure 4 it's a perspective view of the figure 3, there Figure 5 show major scale one detail of figure 3, Figure 6 is similar to Figure 3 which shows a group formed as a result of mating Luer lock connector male according to the invention with a connector female luer lock in one previous condition their deep locking, Figure 7 is a view similar to Figure 6 in the fully locked condition between the male luer lock connector and luer connector female lock, Figure 8 is a schematic, reduced-scale perspective view of the assembly shown in Figures 6 and 7, and Figure 9 is a variant of Figure 8. Referring initially to figures 1 to 4, 1 generically indicates a male luer lock connector according to the invention for medical fluid lines, for example for haemodialysis. The male luer lock connector 1 is made up of two components, both made of moulded plastic material: an elongated tubular body 2 and a threaded bushing 3. The elongated tubular body 2 includes, in a single piece, an initial operating portion 4 equipped with longitudinal gripping projections 5 and whose cavity, indicated by 6, is designed for the attachment of the end of a flexible tube not illustrated in the drawings. The operating portion 4 is followed by a cylindrical intermediate portion 7 in turn joined, via a radial annular shoulder 8, to a cylindrical surface portion 9 of smaller diameter. The cylindrical external surface portion 9 connects to a terminal portion with an external Luer cone 10. As will be seen below, the cylindrical intermediate part 7 can be eliminated, and in that case the annular shoulder 8 will coincide with the edge of the maneuvering part 4 facing the external Luer cone terminal portion 10. The bush 3 has an internal thread 11 and externally a series of axial manoeuvring projections 15. This bush 3 is mounted on the cylindrical external surface portion 9 of the tubular body. 2 rotatable as well as axially slidable for a defined axial advance stroke starting from a retracted position. This retracted position is defined by the axial stop between a front end edge 12 of the bushing 3 and the annular shoulder 8 of the tubular body 2. According to a first fundamental characteristic of the invention, the length of the axial advancement stroke of the bushing 3 is reduced and such, as will be seen below, as not to allow the Luer cone terminal portion 10 of the tubular body 2 to be firmly engaged within the internal Luer cone of a complementary female Luer lock connector (which will be described later with reference to figures 6 and 7) without having previously screwed at least partially the internal thread 11 of the bushing 3 onto the female Luer lock connector. By way of a purely non-limiting example, with the dimensions standardized luer lock connectors of the type corresponding to the invention, the length of this stroke, or the amount of axial play of the bushing 3 on the tubular body 2 indicated with C in figure 5, is less than 0.5 mm, and more conveniently is of the order of 0.3 mm. According to another aspect of the invention, the advancement stroke of the bush 3 is delimited, on the side opposite the annular shoulder 8, by an annular enlargement 13 formed on the portion with cylindrical external surface 9 of the tubular body 2 in the area of ​​connection with the terminal portion with external Luer cone 10. As can also be seen in detail in figure 5, the annular enlargement 13 conveniently has a conical surface diverging towards the terminal portion with external Luer cone 10. In the final section of the advancement stroke of the bush 3, the annular enlargement 13 can be engaged by friction (in the manner shown in figure 7) by an elastically deformable internal portion 14 of the bush 3. This elastically deformable portion 14 has a conical internal surface 16 complementary to that of the annular enlargement 13, and can conveniently be constituted by a crown of radially springy integral axial sectors. Figures 6 and 7 show the coupling / uncoupling modes between the male luer lock connector 1 according to the invention and a conventional female luer lock connector F. This female Luer lock connector F usually comprises a tubular body made of moulded plastic material designed for the connection of a flexible tube H and an internal Luer cone L, complementary to the external Luer cone terminal portion 10 of the male Luer lock connector 1, formed at its free end with external radial projections R which engage with the internal thread 11 of the bush 3. Figure 6 shows a condition of loose engagement between the male connector 1 and the female connector F, with the respective external Luer cones 10 and internal L engaged axially between them after the engagement of the thread 11 on the projections R, but before the bush 3 is fully screwed in. As can be seen in this position, the bush 3 is set back on the cylindrical external surface portion 9, with its front edge 12 substantially abutting against the annular stop shoulder 8. Starting from this position, the screwing of the thread 11 of the bush 3 fully onto the projections R of the female connector F produces on the one hand the axial forcing of the external Luer cone 10 into the internal Luer cone L, and on the other hand the elastic friction engagement of the elastically deformable portion 14 of the bush 3 on the annular enlargement with conical surface 13 of the cylindrical portion 9 of the tubular body 2, in the manner shown in figure 7. In this position the engagement of the male Luer lock connector 1 with respect to the female Luer lock connector L is ensured in an absolutely stable and safe manner. thanks to the friction contact and therefore the cohesion between the bush 3 and the tubular body 2, preventing with the maximum degree of safety any risk of accidental disconnection due to movements, impacts, thermal expansions etc. As regards the voluntary disconnection manoeuvre of the male luer lock connector 1 in relation to the female luer lock connector L, the elastic friction of the elastically deformable portion 14 of the bushing 3 on the annular enlargement with a conical surface 13 allows the value of the unscrewing torque to be increased. between the internal thread 11 and the projections R thus preventing accidental unscrewing and allowing this maneuver only voluntarily. It should be noted that, if at the time of the connection the bushing 3 is not screwed for some reason onto the female luer lock connector L completely or in any case in such a way as to achieve effective friction locking on the annular enlargement 13, any further loosening of the connection such as to reduce the mutual axial engagement between the external luer cones 10 and the internal luer cone L could not in any case cause a complete separation, considering that even in this situation the thread 11 of the socket 3 would remain engaged with the R protrusions of the female F connector. The decoupling between the male luer lock connector 1 and the female luer lock connector L is achieved by unscrewing the bushing 3, which moves back until it stops against the shoulder 8 at the end of the axial travel C. Starting from this position, in which the thread 11 is however in contact with the projections R, the further unscrewing rotation of the compass 3 advantageously produces an action of self-extraction of the external luer cone 10 relative to the internal luer cone L, until they are completely separated from each other. Naturally, the construction details and embodiments may be varied widely with respect to those described and illustrated, without thereby departing from the scope of the present invention as defined in the following claims. Thus, as already clarified above, the intermediate cylindrical part 7 of the tubular body 2 of the connector 1 may be eliminated, the annular shoulder 8 coinciding in this case with the edge of the operating part 4 facing the external luer cone terminal portion 10, as shown in Figure 9.

Claims

CLAIMS 1. Male luer lock connector (1) for medical fluid lines, comprising an elongated tubular body (2) having a cylindrical external surface portion (9) and an external luer cone terminal portion (10), and a bushing (3) mounted on said cylindrical external surface portion (9) of the tubular body (2) in a rotatable and sliding manner for an axial advancement stroke of defined length (C) starting from a retracted position, said bushing (3) having an internal thread (11) with which a female luer lock connector (L) can be screwed into which said external luer cone terminal portion (10) of the tubular body (2) is suitable for axial engagement, characterised by the following combination of features: - said axial stroke (C) has a reduced length and is such that it does not allow said external Luer cone terminal portion (10) of the body (2) of the connector (1) to be firmly engaged in said female Luer lock connector (L) without at least partially screwing said internal thread (11) of said bushing (3) onto said female luer lock connector (L) - said portion with cylindrical external surface (9) of the tubular body (2) of the connector (1) has an annular enlargement (13) which can be elastically engaged by friction by said bushing (3) following the screwing of the internal thread (11) of this onto said female luer lock fitting (L).

2. Connector according to claim 1, characterised by the fact that said annular enlargement (13) has a conical surface diverging towards said terminal portion with an external Luer cone (10).

3. Connector according to claim 2, characterised in that said bushing (3) has a portion elastically deformable radially (14) by said annular enlargement (13).

4. Connector according to claim 3, characterised in that said radially elastically deformable portion (14) of the socket (3) has a conical internal surface (16) complementary to that of said annular enlargement (13).

5. Connector according to any of the preceding claims, characterised in that that the length of said axial stroke (C) is of the order of 0.3 mm.

6. Luer lock connection group for medical fluid lines comprising a female luer lock connector (L) and a male luer lock connector (1) according to one or more of the preceding claims.

7. Connector substantially as described and illustrated and for the purposes specified.