Needle assemblies

1. A needle assembly for mounting on an injection device, comprising:

a main body configured to be removably attached to an injection device in use;

a needle secured in the main body and having a forward portion which projects forwardly from the main body, and

a shield including:

a central portion which is slideably mounted within the main body, the central portion including a cavity for at least partially receiving the needle; and

an actuator portion which extends outside the main body and configured for pushing the shield forward manually in use such that the shield is slideably moveable between

a first position in which the forward portion of the needle projects forwardly of the shield cavity, and

a second position in which said forward portion of the needle is located within the shield cavity; and

wherein the shield and main body are provided with cooperating features comprising

at least one latching element having a resiliently movable leg provided on one of the shield or the main body and

at least one corresponding engagement feature provided on the other of the shield and the main body; comprising a ramped surface, for resiliently deflecting the corresponding latching element as the shield moves in a forward direction and a stepped or barbed profile to prevent rearward movement of the shield relative to the main body when the shield is in the second position,

wherein the latching element rides over the engagement feature and snaps into a latched position as the shield moves into the second position to hold the shield in its second position, and

wherein the actuator is radially spaced apart from the shield central portion and connected at a forward end to extend over the outer wall of the main body in the first position.

2. A needle assembly for mounting on an injection device, comprising:

a main body configured to be removably attached to an injection device in use;

a needle secured in the main body and having a forward portion which projects forwardly from the main body, and

a shield slideably coupled to the main body, the shield including a cavity for at least partially receiving the needle; and

an actuator portion which extends outside the main body and configured for pushing the shield forward manually in use such that the shield is slideably moveable between a first position in which the forward portion of the needle projects forwardly of the shield cavity, and a second position in which said forward portion of the needle is located within the shield cavity; and

wherein the shield and main body are provided with cooperating latching features comprising at least one latching element formed on one of the outer surface of the shield or the inner surface of the main body and at least one corresponding engagement feature, formed on the other of the outer surface of the shield and the inner surface of the main body, comprising a ramped surface, for resiliently deflecting the corresponding latching element as it moves in a forward direction and a stepped or barbed profile to prevent rearward movement of the corresponding latching element when the shield is in the second position;

wherein the latching element rides over the engagement feature and snaps into a latched position as the shield moves into the second position to hold the shield in its second position, and

wherein the actuator is radially spaced apart from the shield central portion and connected at forward end to extend over the outer wall of the main body in the first position.

3. A needle assembly according to claim 1 or claim 2 , wherein the cooperating features are formed on an inner surface of the main body and an outer surface of the shield.

4. A needle assembly according to claim 1 or claim 2 , wherein the at least one latching element is a resiliently moveable leg which rides over a corresponding engagement feature and snaps into a latched position as the shield is moved between the first and second position.

5. A needle assembly according to claim 4 , wherein at least one resiliently moveable leg is provided on an outer surface of the shield central portion; and at least one corresponding engagement feature is provided on an inner wall of the main body.

6. A needle assembly according to claim 1 or claim 2 , wherein the actuator portion extends radially outwardly from the main body of the needle assembly and provides a rear surface for pushing the shield forward manually in use.

7. A needle assembly according to claim 1 or claim 2 , wherein the actuator portion is slideably received in a groove or slot in an outer surface of the main body.

8. A needle assembly according to claim 1 or claim 2 , wherein the cooperating features are configured to provide an audible and/or tactile indication as they engage.

9. A needle assembly according to claim 1 or claim 2 , wherein the shield is mounted in a bore in the main body, wherein the shield and the main body bore have complimentary cross-sectional profiles to prevent relative rotational movement.

10. A needle assembly according to claim 1 or claim 2 , further comprising a stop feature formed between the main body and the shield which blocks forward movement of the shield when the shield reaches the second position.

11. A needle assembly according to claim 1 or claim 2 , wherein the main body comprises first and second components, the needle being secured in the first component and the first component being mounted to or in the rear of the second component.

12. An injection device including a needle assembly according to claim 1 or claim 2 mounted to its forward end.

13. A needle assembly for mounting on an injection device, comprising:

a main body configured to be removably attached to an injection device in use;

a needle secured in the main body and having a forward portion which projects forwardly from the main body, and

a shield including:

a central portion which is slideably coupled to the main body, the central portion including a cavity for at least partially receiving the needle; and

an actuator portion which extends outside the main body and is configured for pushing the shield forward manually in use such that the shield is slideably moveable between

a first position in which the forward portion of the needle projects forwardly of the shield cavity, and

a second position in which said forward portion of the needle is located within the shield cavity; and

wherein the shield and main body are provided with cooperating features comprising

at least one latching element having a resiliently movable leg provided on one of the shield or the main body;

at least one corresponding engagement feature provided on the other of the shield and the main body comprising a ramped surface on a forward end of the engagement feature, for resiliently deflecting the corresponding latching element as the shield moves in

a forward direction and a stepped profile to prevent rearward movement of the shield relative to the main body when the shield is in the second position, and

a cylindrical opening on the forward end of the shield,

wherein the latching element rides over the engagement feature and snaps into a latched position as the shield moves into the second position to hold the shield in its second position, and

wherein the actuator is radially spaced apart from the shield central portion and connected at a forward end to extend over the outer wall of the main body in the first position.