Patent ID: 8721593

Claim:
An injection device, comprising: a syringe disposed within a housing; a drive element moveable from a first position to a second position to expel a dose from said syringe; and a magnetically-operated indicator for indicating an injection is complete, said magnetically-operated indicator including two co-acting elements, a first of said two co-acting elements being associated with said drive element, and a second of said two co-acting elements being associated with said housing, said first and second co-acting elements arranged such that, as said drive element arrives at or near said second position, a relative position of said first and second co-acting elements is changed by an influence of a magnetic force acting therebetween, wherein said second of said co-acting elements comprises a captive element and the first of said co-acting elements comprises a moveable element, and wherein a ferro-magnetic keeper element is associated with said drive element and configured to temporarily restrain said moveable element until said moveable element is moved under the influence of said magnetic force due to a proximity of said captive element.