Patent attributes
The present invention relates to a medical delivery device comprising a housing (10); a medicament container (16) arranged to be placed in said housing; a stopper (18) movable within said container; a medicament dispensing means attachable to said housing and to said container through which medicament can be expelled; characterized in that the device further comprises a power unit (22) comprising a cover (24), a volute spring (26) arranged within said cover, and a pressure member (28) having a pressure pad (30) in contact with the stopper, a guide rod (34) extending into the volute spring and an annular ledge (32) in contact with the edges of the volute spring; activation means (36) mechanically connected to the cover and to the housing; and a spring locking means mechanically connected to said activation means, wherein said spring locking means (39) comprises a deformable ring-shaped member having (40) an inner diameter somewhat larger than the annular ledge, such that said ring-shaped member presents an oval shape when it is in contact with the annular ledge for locking the volute spring in a tensioned state.
