Patent ID: 7955303
Filing Date: 2011-06-07
Classification: A61M

Abstract:
1. An injection device for injecting a substance, the device comprising: a casing comprising a reservoir for the substance; an operating button for selecting a dosage of the substance to be injected, said button moveable relative to the casing in a dosing movement and a correction movement opposite to the dosing movement; a slip coupling comprising co-operating latching elements engageable with each other and coupling the operating button to the casing in discrete latching positions during the movements of the operating button; and a spring member which opposes the movement of the operating button in at least one of the movements; wherein one of the latching elements is shaped asymmetrically with respect to the two movements in which the latching elements can be moved relative to each other such that when the latching elements are engaged in the dosing movement and the correction movement, there is a lower resistance to movement of the operating button in one of the movements than in the other movement.