WO2017066846A1

WO2017066846A1 - Thread-locking luer

Info

Publication number: WO2017066846A1
Application number: PCT/AU2016/050999
Authority: WO
Inventors: Chris Whelan
Original assignee: Chris Whelan
Priority date: 2015-10-23
Filing date: 2016-10-24
Publication date: 2017-04-27

Abstract

The combination of a first component (10) having a threaded female bore (20) with an axis, the female bore (20) surrounded by a first mating portion (30) and a second component (14) having a threaded male portion (21) adapted to be screwed into the female bore (20) and extending from a second mating portion (50) and the first mating portion (30) includes at least one first axially extending locking surface (36) and the second mating portion (50) includes at least second first axially extending locking surface (56) such that when the first and second mating portions (30, 50) are in contact with each other the first and second locking surfaces (36, 56) resist unscrewing of the first and second components.

Description

Thread-Locking Luer

Field of Invention

This invention relates to luer fittings and more particularly to assemblies having a luer fitting that is locked in position once assembled. Background

The Luer taper is a standard fitting for connecting two medical components together having complementary male and female connectors.

It is common to provide a component of an assembly with a male or female Luer fitting, to allow connection of the assembly to another device. It is common to provide the luer component with a screw thread to allow the luer component to be screwed into another component of the assembly. Luer fittings have a taper on the male and female parts that engage together in a fluid tight manner and are held together by friction without the need for any other securement. However, to break the friction lock it is common for the male and female luer components to be rotated relative to each other. In addition, locking luer connections must be rotated relative to each other to disengage.

Where one of these components is itself screwed into another component, the act of twisting to break the luer connection (either with a 'normal' or locking luer connection) can result in unscrewing of the luer component. Where that luer component has a cannula or other needle stick risk item, this can result in unintended risk of a needle stick injury.

Accordingly it is desirable to provide a connection that allows a first component to be screwed into a second component but to prevent subsequent unscrewing of the two components.

Summary of the Invention

In one broad form the invention provides the combination of a first component having a threaded female bore or socket with an axis, the female bore surrounded by a first mating portion and a second component having a threaded male portion adapted to be screwed into the female bore and extending from a second mating portion, the first and second components adapted to be screwed together with at least part of the first and second mating surfaces in contact with each other, and

wherein

the first mating portion includes at least one first axially extending locking surface and the second mating portion includes at least second first axially extending locking surface,

wherein, when the first and second mating portions in contact with each other the first and second locking surfaces resist unscrewing of the first and second components.

Preferably at least one of the first and second locking surfaces is generally planar but need not be.

Preferably at least one of the first and second locking surfaces extends generally parallel to the axis. However one or both may be angled to the axis.

In axial end view at least one of the first and second locking surfaces may be parallel to and/or lie on a radial line from the axis. However at least one of the first and second locking surfaces may be angled to a radial line.

At least one of the first and second locking surfaces may extend in the axial direction generally parallel to the axis but may be angled to the axis.

When angled to the axis preferably a locking surface is angled more to the thread than the axis, i.e. it is undercut.

Preferably one and more preferably both mating portion each include at least one ramp surface to ease relative rotation in a direction that draws the two components together. The at least one ramp surface preferably extends axially toward the other component in the rotational direction that tightens the components together

There may be at least one third surface generally perpendicular to the axial direction extending from an edge of a locking surface. The at least one third surface may be planar and extend in a plane generally perpendicular to the axial direction.

Where a ramp surface is provided the at least one third surface may extend between the ramp surface and the locking surface. A first third surface may extend from a first edge of a locking surface to a first edge of a ramp surface. A second third surface may extend from a second edge of a locking surface to a second edge of a ramp surface.

The number of first and second locking surfaces need not be the same.

Where a component includes at least one ramp surface, preferably the at least one ramp surface and a respective at least one locking surface form a saw tooth.

Preferably both components include at least one ramp surface and at least one locking surface arranged as a saw tooth.

The female bore or socket may be a blind bore or socket or may be open at both ends.

One of the components may include a locking or non locking luer fitting. The luer fitting may be a male or female luer fitting.

One of the components may include a cannula.

Where one of the components includes a cannula the other component may be or include a protective shield for the cannula.

In one form of the invention a one component is a needle assembly having a luer fitting and a cannula and the other component is a sampling cap, that when attached to the needle assembly prevents or limits access to the cannula. Preferably the cap has the female threaded bore or socket and the needle assembly has a threaded male portion. Brief Description of the Drawings

Figure 1 is a plan view from above of a subculture cap assembly according to an embodiment of the invention.

Figure 2 is a side view of the subculture cap assembly of figure 1 .

Figure 3 is an end view of the subculture cap assembly of figure 1 .

Figure 4 is a cross sectional view of the subculture cap assembly of figure 1 taken along line AA in figure 2.

Figure 5 is a detail view of part of the subculture cap assembly of figure 5.

Figure 6 is a cross sectional view of the subculture cap assembly of figure 1 taken along line BB in figure 3.

Figure 7 is a detail view of part of the subculture cap assembly of figure 6.

Figure 8 is a perspective view from above of the subculture cap assembly of figure 1 .

Figure 9 is a perspective view from above of the subculture cap assembly of figure 1 with a male slip luer fitting.

Figure 10 is an exploded perspective view from below of the subculture cap assembly of figure 1 .

Figure 1 1 is a detail view of the needle assembly part of the subculture cap assembly of figure 10.

Figure 12 is an exploded perspective view from above of the subculture cap assembly of figure 1 .

Figure 13 is a detail view of the cap part of the subculture cap assembly of figure 10.

Figures 14 to 18 show various alternative configurations of locking members. Figures 19 and 20 show the subculture cap assembly of figure 1 mounted on a subculture bottle. Detailed Description of Preferred and other Embodiments

Referring to the drawings there is shown a subculture cap assembly 10 comprising cap 12 and needle assembly 14 that is intended to be used to withdraw samples of fluid form a sub culture bottle 100.

The subculture cap 10 is provided with a needle assembly 14 that includes a cannula 16 surround by a rubber sheath 18. The needle assembly has a threaded portion 20 and is screwed into threaded aperture 22 in the

subculture cap 10, so the sheathed cannula 16 extends axially within the cap. The needle assembly may include a male or female luer fitting. Figures 1 to 5 shows a subculture cap assembly with a female luer fitting whilst figures 6 and 7 shows a subculture cap assembly with a male luer fitting. The female luer fitting of figures 1 to 5 is also a locking luer fitting but the male or female luer fittings may be either locking or non-locking. A drip device maybe mounted on the luer fitting of the needle assembly to allow samples from a sub culture bottle to be taken.

In prior art devices the needle assembly 14 merely screws into the threaded aperture 22. To resist unscrewing once assembled, various techniques have been used. These techniques include making the male and female threads interference fit and making the pitch of the male and female threads slightly different. Whilst these techniques increase resistance to unscrewing they do not prevent it. Further, because these products are usually formed of plastics material there are limits on the stresses that can be applied to the threads so there is a limit to how "tight" the two components can be screwed together.

The subculture cap 10 and the needle assembly 14 of the invention instead use a separate locking system, either alone or in addition to the techniques described above.

The subculture cap 10 has a flange 30 surrounding the threaded aperture 20 into which the needle assembly 14 screws. The flange 30 is provided with a series of angled "saw teeth" 32 extending circumferentially around the aperture 22. As best seen in figure 13 each tooth 32 has a ramp surface 34 angled slightly to a plane perpendicular to the axis (i.e. angled slightly to the rotational direction of the thread) and a locking surface 36 substantially parallel to the axis. The ramp surface 34 is angled to a plane perpendicular to the axis away from the cap in the rotational direction of the thread, so for a conventional right hand thread the ramp surfaces 32 extend upwards in a clockwise direction, when viewed from above, as in figure 13.

A generally planar surface 38 extends from the top edge 40 of angled ramp surface 34 to the top edge 42 of the locking surface 36. In this embodiment the top edge 40 does not extend radially relative to the bore. This may be achieved by angling one or both of surfaces 32 and 38 to a radial line extending perpendicular to the axis. In the embodiment shown the surface 38 is generally perpendicular to the axis of the bore and the ramp surface 34 is angled. If desired the top edge 40 may extend radially relative to the bore. In this embodiment the lower edges of the ramp 34 and locking surfaces 36 are the same edge 46.

Referring to figure 11 the needle assembly 14 has a flange 50 adjacent the upper end of the thread 20 on the needle assembly 14 and this flange 50 has saw teeth 52, each comprised of a ramp surface 54 angled to a plane perpendicular to the axis (i.e. angled slightly to the rotational direction of the thread) and a locking surface 56 substantially parallel to the axis. The ramp surfaces 54 are angled away from the end of the cannula in the rotational direction of the thread 21 , so for a conventional right hand thread the ramp surfaces 54 extend toward the free end of the cannula in a clockwise direction, when viewed from the free end of the cannula. The ramp surfaces 34 and 54 are generally complementary to each other, as are locking surfaces 36 and 56.

When the needle assembly 14 is screwed into the cap the ramp surfaces 36 and 54 are thus generally parallel to each other. The needle assembly 14 may be screwed in until the 'highest' point of the saw teeth 52 of needle assembly 14, the edge 58 at junction of surfaces 54 and 56, contacts the ramp or upper surfaces 34, 38 of the cap 10. Because, preferably, both sets of saw teeth are formed of flexible plastics material, the teeth and threads distort and allow the needle assembly 14 to be screwed further into the cap 10, with that edge 58 riding over the ramp surface 36 and upper surface 38 until the edge 42 is reached, at which point compression forces on the teeth are reduced or removed, allowing the teeth to relax, with the junction moving down alongside the locking surface 36, causing the locking surfaces 36 and 58 to overlap axially. Rotation over additional teeth 32 increases this overlap.

Because locking surfaces 36 and 56 are substantially parallel to the axis, once there is significant overlap, such as when the two components are tightly screwed together, rotation in the opposite direction to unscrew the needle assembly 14 is prevented. Accordingly, once the needle assembly 14 has been screwed into the cap and tightened, it cannot be unscrewed. As such, the action to break a locking or non locking luer connection cannot unscrew the needle assembly 14 from the cap.

The number of teeth on the two components need not be the same. In the embodiment shown the cap 10 is provided with eight teeth 32 whilst the needle assembly 14 is provided with four teeth 52. If desired there could be a single tooth on one or both of the components. Only one of the components requires a ramp surface and there could be non tooth like locking member(s) on the other component.

It will also be appreciated that it is not critical that there be saw teeth on both components. One component may have saw teeth whilst the other has one or more extensions, protrusions or the like that have a surface that engages the axially extending locking surface of a saw tooth.

Whilst the embodiment show has saw teeth 30 in which the angled ramp surfaces 32 each extend from the base of the axially extending locking surfaces 36, it will be appreciated that there may be a third surface extending (preferably perpendicular to the axis) between the base of each locking surface 34 and the adjacent ramp surface 32. Similarly the upper surface 38 may be omitted from the teeth 32 or added to the teeth 52. Figures 14 to 18 show a number of variations of the teeth on the cap 12 and the needle assembly 14, including variations in which upper surface 38 is omitted, variations in which there is a tooth on the needle assembly for each tooth on the cap, variations in which there is a lower surface 138 between the locking surface 38 and ramp surface 36. A variation is shown in which the needle assembly has teeth 252 that do not have a ramp surface and only a locking surface 56. Another variation shows a needle assembly has teeth with a planar surface 238 between the locking and ramp surfaces.

The cap assembly 10 includes a lid 60 connected to the cap 12 at hinge 62. The lid 62 includes a catch or protrusion 64 that engages with catch or protrusion 66 on the cap 12. This serves to hold the lid in the open position when the cap is used inverted, which is the normal method of use.

The cap also includes at least one internal protrusion 68, preferably 3 or more spaced around the cap at a position to engage under the free edge 104 of an external cap of a subculture bottle, so as to aid retention of the cap assembly 10 on the subculture bottle when inverted.

Whilst the invention has been described with reference to a sampling cap and a needle assembly it will be appreciated that the invention is not limited to use with either or both of these components and may be used for securely holding any two components together.

Unless the context clearly requires otherwise, throughout the description and any claims the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". The features of the invention described or mentioned in this document may be combined in any combination of features where features are not mutually exclusive.

It will be apparent to those skilled in the art that many obvious modifications and variations may be made to the embodiments described herein without departing form the spirit or scope of the invention.

Claims

The Claims

1 . The combination of a first component having a threaded female bore with an axis, the female bore surrounded by a first mating portion and a second component having a threaded male portion adapted to be screwed into the female bore and extending from a second mating portion, the first and second components adapted to be screwed together with at least part of the first and second mating portions in contact with each other, and

wherein the first mating portion includes at least one first axially extending locking surface and the second mating portion includes at least second first axially extending locking surface, wherein,

when the first and second mating portions are in contact with each other the first and second locking surfaces resist unscrewing of the first and second components.

2. The combination of claim 1 wherein at least one of the first and second locking surfaces is generally planar.

3. The combination of any one of the proceeding claims wherein in the axial direction at least one of the first and second locking surfaces extends generally parallel to the axis.

4. The combination of claim 1 or claim 2 wherein in the axial direction at least one of the first and second locking surfaces is angled to the axis.

5. The combination of claim 4 wherein at least one of the first and second locking surfaces is angled more to the thread than the axis.

6. The combination of any one of the proceeding claims wherein, in axial end view, at least one of the first and second locking surfaces is parallel to a radial line from the axis.

7. The combination of any one of claims 1 to 5 wherein, in axial end view, at least one of the first and second locking surfaces is angled to a radial line from the axis.

8. The combination of any one of the proceeding claims wherein at least one of the first and second mating portions includes at least one ramp surface to ease relative rotation in a direction that draws the two components together.

9. The combination of claim 8 wherein at least one ramp surface extends axially toward the other component in the rotational direction that tightens the components together.

10. The combination of claim 8 or claim 9 wherein at least one ramp surface is parallel to a radial line from the axis.

1 1 . The combination of any one of claim 8 or claim 9 wherein at least one ramp surface is angled to a radial line from the axis.

12. The combination of any one of the proceeding claims wherein at least one mating portion includes at least one third surface extending from an edge of a locking surface.

13. The combination of claim 12 wherein at least one mating portion includes at least one third surface extending in a plane generally

perpendicular to the axial direction.

14. The combination of claim or claim 13 wherein the at least one third surface extends between the respective ramp and locking surfaces.

15. The combination of any one of claims 12 to 14 when dependent on claim 8 wherein at least a first third surface extends from a first edge of a locking surface to a first edge of a ramp surface.

16. The combination of any one of claims 12 to 15 when dependent on claim 8 wherein at least a second third surface extends from a second edge of a locking surface to a second edge of a ramp surface.

17. The combination of claim 16 wherein, in axial end view, the second edge of the locking surface is angled to a radial line from the axis.

18. The combination of claim 16 wherein, in axial end view, the second edge of the ramp surface is angled to a radial line from the axis.

19. The combination of any one of the proceeding claims when dependent on claim 8 wherein at least one ramp surface and a respective at least one locking surface form a saw tooth.

20. The combination of any one of the proceeding claims when dependent on claim 8 wherein the first and second components include at least one ramp surface and at least one locking surface arranged as a saw tooth.

21 . The combination of any one of the proceeding claims wherein the female bore is open at both ends.

22. The combination of any one of the proceeding claims wherein one of the first and second components includes a locking or non locking luer fitting.

23. The combination of any one of the proceeding claims wherein one of the first and second components includes a cannula.

24. The combination of any one of the proceeding claims wherein one of the first and second components includes a cannula the other component is or includes a protective shield for the cannula.

25. The combination of any one of the proceeding claims wherein one of the first and second components is a needle assembly having a luer fitting and a cannula and the other component is a sampling cap, that when attached to the needle assembly, prevents or limits access to the cannula.

26. The combination of claim 25 wherein the cap has the female threaded bore or socket and the needle assembly has the threaded male portion.