| abstract |
When the injection device is applied to a patient's skin and a plunger (9) is pressed, the entire syringe and a carrier (23) move forwards in relation to a barrel (1), a spring (35) is compressed and a needle (11) is fully projected. Further pressing on the plunger (9) ejects the dose. The needle shroud (14) is kept at the rearward position by its firm engagement around the injection area. On withdrawal of the device, the shroud (14) is pushed forwards by the spring (35) to protect the needle (11). At the same time barbs (19) on the endsof the fingers (17) re-engage the rear end of the syringe carrier (23), whose flanges (25) are up against the rib (21), thus thwarting any attempt that may be made to pull the needle shroud clear of the barrel. The shroud (14) is therefore trapped, the needle (11) safely within. |