A DOSE SETTING MECHANISM AND AN INJECTION SYRINGE HAVING SUCH A DOSE SETTING MECHANISM

摘要

Dose setting mechanism for a drug delivery device has a rotatable element (5) connected via a wheel (11) and a coupling ring (12) to a piston rod (13). A button (7) rotates the ring and the wheel to move the rod and deliver the dose. Either the ring partly surrounds the wheel or vice versa. The ring may connect to a gear (17) engaging teeth (25) on the rod. Also claimed is an injection syringe fitted with the above mechanism.