GB0107604D0 — Improvements in and relating to injection device

USPTO Abstract

Injection devices are known for the self administration of medicament by patients. The medicament 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 the 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bung within the cartridge to be moved both to a maximum dispense position within the cartridge and to be fully withdrawn from the cartridge to allow for replacement of the cartridge.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 injecting device is disclosed in which the drive mechanism comprises a displaceable dosing spindle 6 , a dial dose means 8 , a transmission means 10 , and a cable means 12 , a piston comprising a plurality of nested piston members 30, 32, 34 , displacement of the transmission means 10 causing the cable means 12 to move at least one of one of the nested piston members to drive a cartridge bung 18.