| 摘要 |
Injection devices are known for the self administration of medicament by patients in which the medicaments is typically contained within a cartridge located within the injection device. It is a problem that injection devices should be small enough to fit into a jacket pocket or a hand bag without difficulty. Also, the injection device must be of a size that enables a piston or similar used to drive a cartridge bung within the cartridge to be moved both to a maximum dispense position within the cartridge and to be fully withdrawn from the cartridge to allow for replacement of the cartridge. A drive mechanism for an injection device is disclosed in which a piston (48) is successively moved along the first axis to drive a bung (20) into a medicament cartridge (18), a displacement mechanism comprising a dose setting spindle (30) is disposed along a second axis, the second axis being parallel to the first axis, transmission means connected between the dose setting spindle (30) and the piston (20), and displacement means to displace the dose setting spindle (30) with respect to the medicament cartridge (18), a movement of the displacement means in a first direction causing movement of the dose setting spindle (30) and the piston (20) in the first direction. |
