WO2004052432A2

WO2004052432A2 - Retracting needle safety syringe with anti-rotation means

Info

Publication number: WO2004052432A2
Application number: PCT/GB2003/005292
Authority: WO
Inventors: David William Parker; Colin Hamilton Burgess
Original assignee: David William Parker; Colin Hamilton Burgess
Priority date: 2002-12-06
Filing date: 2003-12-03
Publication date: 2004-06-24
Also published as: AU2003290228A8; AU2003290228A1; WO2004052432A3; GB0228515D0

Abstract

A syringe comprises a housing (1), a needle carrier (2) and a needle retraction (2.1, 5.1, 6) mechanism. The syringe is provided with anti-rotation means to prevent rotation of the needle carrier relative to the housing, e.g. when a user installs a needle (3) with a luer lock or screw fitting or removes a needle sheath (3.1) using a twisting motion. The anti-rotation means may comprise a gripping surface (2.4) or an attachment (3) secured to the needle carrier, for engagement by the user, or co-operating formations (1.4, 2.3, 2.8, 2.10) on the housing (1) and needle carrier (2). The anti-rotation means may include an additional component 7 that co-operates with formations (1.2, 2.6) in the housing (1) and/or needle carrier (2). Means for resisting axial movement of the needle carrier (2) relative to the housing (1) may also be provided. Where the anti-rotation means comprises an attachment (3) or additional component (7), the same attachment (3) or additional component (7) may be used to resist such axial movement.

Description

Improvements in or relating to retracting needle safety syringes

The invention relates to means for preventing rotation of a needle carrier in a safety syringe.

Recently, there has been an increasing worldwide demand for safe hypodermic syringes, such as passive syringes with retractable needles, examples of which are disclosed in our co-pending patent applications O00/ 18454, WO01 /43619 and O01 /72362.

It is desirable for a syringe to allow a user to be able to fit the needle, in order to allow a user to select an install a needle according to their needs and to replace unsuitable or damaged needles. However, a problem arises in this development in the difficulty of ensuring positive fitment and retention of the needle. Where a needle mounted onto a needle carrier in a syringe housing by a simple push fit, the needle may not be securely retained. These problems may be exacerbated in a retractable needle assembly, where an insecure engagement between the needle and needle carrier may cause the needle to become detached during retraction. In addition, the act of pushing of the needle into the needle carrier may exert an unacceptable load on means retaining the needle carrier in the syringe housing. If, alternatively, the needle is attached to the needle carrier by means of a luer lock, it is necessary for a user to axially rotate the needle relative to the needle carrier in order to effect the lock. The use of such an arrangement with a retractable needle carrier may be problematical as rotation of the needle may lead to rotation of the needle carrier relative to the syringe housing, making secure engagement of the needle difficult.

In a first aspect of the invention, a retractable needle syringe comprises a housing, a needle carrier located in the housing and a needle retraction mechanism, wherein a portion of the syringe is adapted to form an anti-rotation means for interaction with a user in order to prevent rotation of the needle carrier. The anti-rotation means may be in the form of a gripping surface or an attachment secured to the needle carrier, which may be engaged by the user during needle fitting in order to resist rotation of the needle carrier.

In a second aspect of the invention, a retractable needle syringe comprises a housing, a needle carrier located in the housing, a needle retraction mechanism and anti-rotation means for preventing rotation of the needle carrier relative to the housing, wherein the anti-rotation means comprises co-operating formations provided on the housing and needle carrier.

Examples of suitable co-operating formations include one or more projections together with one or more surfaces for engaging the projections, or one or more projections together with corresponding receiving formations, such as splines and grooves or castellations located on abutting faces of the needle carrier and the housing.

In a third aspect of the invention, a retractable needle syringe comprises a housing, a needle carrier located in the housing, a needle retraction mechanism and anti- rotation means for preventing rotation of the needle carrier relative to the housing, wherein the anti-rotation means comprises an additional component and co-acting formations for co-operating with said additional component provided in. the housing and needle carrier.

For example, the additional component may be a pin and the receiving formations may be holes arranged to receive said pin or surfaces configured to engage said pin in the needle carrier and/ or housing.

By preventing rotation of the needle carrier, the needle may be secured using a rotating movement, e.g. in a luer lock or a screw arrangement. Rotation of the needle carrier within the syringe housing is prevented, where such rotation would prevent full tightening of the needle. In addition, a syringe may be supplied to a user with a pre-mounted needle and a protective sheath, in order to prevent damage to the needle and needle-stick injury to persons handling the syringe. The provision of anti-rotation means facilitates removal of the sheath using a twisting motion, in which the sheath is rotated relative to the needle and/ or needle carrier.

Preferably, the retractable needle syringe comprises means for resisting axial movement of the needle carrier relative to the housing. In particular, where an attachment or additional component is used in preventing rotation of the needle relative to the housing, the same attachment or additional component may be used in order to resist such relative axial movement.

The invention is suitable for use with standard and non-standard luer lock needles and luer slip needles. The invention can also be applied to needles with other types of fittings.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 depicts a syringe according to a first embodiment of the invention;

Figure 2 is a cross-sectional view of a distal end of a safety syringe according to the first embodiment of the invention;

Figure 3 is a perspective view of a distal end of a safety syringe according to a second embodiment of the invention; Figure 4 is a cross-sectional view of a distal end of a safety syringe according to a third embodiment of the invention;

Figure 5 is a cross-sectional view of a distal end of a safety syringe according to a fourth embodiment of the invention;

Figure 6 is a cross-sectional view of a distal end of a safety syringe according to a fifth embodiment of the invention,

Figure 7 is a cross-sectional view of a distal end of a safety syringe according to a sixth embodiment of the invention. Figure 1 depicts a syringe according to a first embodiment of the present invention, comprising a housing 1 and a needle carrier 2 located in a distal end of the housing 1 for receiving a needle 3. A plunger 4 is located inside the housing 1, comprising means for retaining a piston 5 and a stored energy configuration for effecting needle retraction, e.g. a spring 6. The piston 5 comprises a co-operating formation 5.1 that is configured to co-act with a complementary formation 2.1 on the needle carrier 2 to form a catch so that, on completion of an injection stroke, the piston 5 becomes attached to the needle carrier 2. The stored energy configuration 6 is then released to draw the needle carrier 2 and needle 3 into the housing 1. Further details of the needle retraction mechanism are provided in our co-pending application WO00/18454.

Figures 2 to 7 show alternative configurations of the needle carrier 2 and housing 1. In each embodiment, the needle carrier 2 may be retained by means of a reversible catch 2.2 (not shown in Figures 1, 6 and 7), which co-acts with an aperture 1.1 in the housing 1. The needle carrier 2 comprises a standard luer lock 2.3 for receiving the standard luer lock needle 3. The luer lock 2.3 and needle 3 comprise cooperating locking features which are engaged by inserting the needle 3 into the lock 2.3 and rotating the needle 3 relative to the lock 2.3 and needle carrier 2.

With reference to Figure 2, in the first embodiment of the invention, a portion 2.4 of the exterior surface of the needle carrier 2 is textured to provide a finger grip for a user. When the needle is rotated in order to effect the luer lock, rotational movement of the needle carrier 2 can be resisted by the user gripping the textured portion 2.4. Similarly, where the needle 3 is covered with a protective sheath 3.1, the user may remove the sheath 3.1 using a twisting motion while preventing rotation of the needle carrier 2 and needle 3 by gripping the textured portion 2.4.

Figure 3 depicts a second embodiment of the invention. In this embodiment, the load created by fitting a needle into the luer lock 2.3 may be resisted by a user with the assistance of a fork 3. The fork 3 is fitted into one or more slots 2.5 and retained by a catch 3.1. When fitting a needle 3 or removing a sheath 3.1 , a user may grip or bear against the fork 3 in order to prevent its rotation so that, due to the interaction of the fork 3 and slots 2.5, the needle carrier 2 does not rotate. In addition, the fork 3 will prevent accidental overriding of the retaining catch 2.2.

The fork 3 must be removed prior to injection in order to permit retraction of the needle into the syringe housing 1. The fork 3 may carry also information on its surface, for example, if the syringe is supplied to the user pre-filled, the fork may carry information identifying the injectant, its manufacturer, batch number, expiry date etc. The information may include a notice reminding the user to remove the fork 3 before carrying out an injection.

In a third embodiment of the invention, shown in Figure 4, rotation of the needle carrier 2 relative to the syringe housing 1 is prevented by a pin 7. The pin 7 co-acts with a flat portion 2.6 formed on the needle carrier 2 and is retained in a hole 1.2 in the syringe housing 1. The hole 1.2 is preferably a through hole in order to provide the arrangement with extra stability. However, in an alternative embodiment, the hole 1.2 may be a blind hole. In either of these arrangements, a co-acting hole may be provided on the needle carrier 2 in place of the flat portion 2.6.

The pin 7 prevents accidental overriding of the catch 2.2 in a similar manner to the fork 3 of the second embodiment.

Figure 5 depicts a fourth embodiment of the invention, where the needle carrier 2 is shown cut away at 2.7 to reveal a spline 1.3 in the distal end of the housing 1. The spline 1.3 co-acts with a groove 2.8 formed in a flange 2.9 of the needle carrier 2 to prevent rotation of the needle carrier 2 relative to the syringe housing 1. A plurality of splines 1.3 and grooves 2.8 may be provided for this purpose.

Figure 6 depicts a syringe according to a fifth embodiment of the invention. Here, the needle carrier 2 has one or more projections 2.10 extending from a flange 2.9, which co-act with cut-outs 1.4 in the aperture 1.1 of the syringe housing 1 to prevent rotation of the needle carrier 2 relative to the syringe housing 1 during needle fitting. In a sixth embodiment of the invention, shown in Figure 7, a syringe comprises castellations 2.11 on a flange 2.9 of the needle carrier 2. The castellations 2.11 co- act with a similar formations 1.5 provided at an inner surface 1.6 of the distal end of the housing 1. Relative rotation of the needle carrier 2 and syringe housing 1 during needle fitting is prevented by engagement of the castellations 2.11 with formations 1.5.

Although the invention has been described by way of examples relating to the fitment of a standard luer lock needle, the invention is suitable for use with non- standard luer lock needles and luer slip needles. The invention may also be applied to needles with other types of fittings for facilitating needle fitting and/ or removal of a needle sheath 3.1.

Furthermore, while each embodiment comprises a single anti-rotation means, a syringe according to the invention may comprise a combination of two or more anti-rotation means.

Claims

1. A retractable needle syringe comprising a housing, a needle carrier located in the housing and a needle retraction mechanism, wherein a portion of the syringe is adapted to form an anti-rotation means for interaction with a user in order to prevent rotation of the needle carrier.

2. A retractable needle syringe according to claim 1, wherein the anti-rotation means comprises a grip surface provided on a portion of the needle carrier.

3. A retractable needle syringe according to claim 1, wherein the anti-rotation means is an attachment secured to the needle carrier.

4. A retractable needle syringe comprising a housing, a needle carrier located in the housing, a needle retraction mechanism and anti-rotation means for preventing. rotation of the needle carrier relative to the housing, wherein the anti-rotation means comprises co-operating formations provided on the housing and needle carrier.

5. A retractable needle syringe according to claim 4, wherein the co-operating formations comprise a projection and an engagement surface for engaging said projection.

6. A retractable needle syringe according to claim 4, wherein the co-operating formations comprise one or more projections and one or more receiving formations.

7. A retractable needle syringe according to claim 4, wherein the co-operating formations are castellations located on abutting faces of the needle carrier and the housing.

8. A retractable needle syringe comprising a housing, a needle carrier located in the housing, a needle retraction mechanism and anti-rotation means for preventing rotation of the needle carrier relative to the housing, wherein the anti-rotation means comprises an additional component and receiving formations for receiving said additional component provided in the housing and needle carrier.

9. A retractable needle syringe according to claim 8, wherein the additional component is a pin and the receiving formations are holes in the needle carrier and housing.

10. A retractable needle syringe according to any one of the preceding claims, comprising resisting means for preventing axial movement of the needle carrier relative to the housing.

11. A retractable needle syringe according to claim 10, wherein the resisting means comprises an attachment secured to the needle carrier.

12. A retractable needle syringe according to claim 10, wherein the resisting means comprises a pin received in holes in the needle carrier and housing.

13. A retractable needle syringe substantially as hereinbefore described and illustrated in the accompanying drawings.