Latching Blocking Mechanisms and Safety Medical Needle Assemblies

A safety medical needle assembly, comprising:

• a tubular component including an internal elongate guide;
• an abutment surface formed on the tubular component;
• a movable component disposed within the tubular component and arranged for axial sliding movement with respect thereto between initial and shifted positions, the movable component being adapted to receive the hub of a medical needle so that the needle projects within but is protected by the movable component when in its initial position;
• a control member arranged for axial movement with the movable component but rotatable with respect to the movable component, the control member initially being disposed at a first position relative to the movable component;
• control means arranged to urge the control member towards a second position angularly displaced from the first position, which control means becomes active only after the control member has turned through a predetermined angle towards the second position;
• and
• a camming part on the tubular component co-operable with a moving camming part on the control member and arranged to turn the control member through said predetermined angle from its first position on axial movement of the movable component towards its shifted position to cause the needle to project from the movable component;
• whereby the movement of the movable component towards its shifted position to cause the needle to project therefrom also causes the control member to turn through said predetermined angle whereafter the return of the movable component towards its initial position allows the control member to move behind the abutment surface under the action of the control means, thereafter to block further axial movement of the movable component towards its shifted position.