MEDICAMENT NNJECTION DEVIVE WITH AXIALLY DISPLACEABLE LEAD SCREW

摘要

The present invention relates to a medicament delivery device in which the medicament to be delivered is stored within a cartridge having a displaceable piston therein. The displaceable piston is driven to expel medicament by way of a lead screw (6) that is advanced and retracted by way of a suitable drive mechanism (14). A guideway (16) through which the lead screw travels is provided. However, in known devices the guideway is held in position by other components of the apparatus. Such devices can be complex to manufacture. Also they may require disassembly and reassembly when a cartridge is to be replaced. This is a disadvantage if the user, as is common amongst those with diabetes, is infirm or has impaired vision. A medicament delivery device is disclosed comprising a main housing (3), a threaded lead screw (6) having opposing flat surfaces, rotary driving means (14) having inner wall surfaces corresponding to the opposing flat surfaces of the lead screw and a guide housing (16) having an opening through which the threaded lead screw is received wherein the guide housing is permanently fixed to the main housing.