An auto-injector for receiving and operating a syringe, the auto-injector comprising: a housing for receiving the syringe, the housing comprising a main body and a hinged door operable into an open position and a closed position, wherein the syringe is receivable within the housing when the hinged door is in the open position; at least one charging link connected between the main body and the hinged door, wherein the connection of the charging link to the main body and/or the connection of the charging link to the hinged door is a slidable connection configured to slide on opening and closing of the hinged door and configured to couple to the at least one drive spring for priming thereof on opening and/or closing of the hinged door, the at least one drive spring being configured on activation of the auto-injector to drive a plunger driver forward within the auto-injector to operate the syringe received within the auto-injector.本發明提供了一種自動注射器,自動注射器係用於容納一注射器並進行操作,自動注射器係包含:殼體,用於容納注射器,注射器包含主體及鉸接門,鉸接門可於開放位置及閉合位置處操作,當鉸接門處於開放位置時,注射器可容納於殼體內;以及裝載連桿,係連接於主體與鉸接門之間,其中裝載連桿與該主體間之連接和/或裝載連桿與該接門間之連接為可滑動連接,可滑動連接被配置成透過滑動實現鉸接門之開放與閉合,並且可滑動連接被配置成與至少一個驅動彈簧相耦合,藉以於開啟和/或關閉該鉸接門上裝填至少一個驅動彈簧;其中,至少一個驅動彈簧被配置成在啟用自動注射器時於自動注射器內向前驅動柱塞驅動器,藉以對自動注射器內所容納之注射器進行操作。