butterfly spring การใช้

• They throw their rifle bolts and the Lewis Gun's butterfly spring out of the door, and stuff their hats and jackets up their tunics.
• Mainwaring admits he must report Frazer to GHQ for court-martial but, just in the nick of time, Frazer discovers the butterfly spring in his trouser pocket.
• Frazer is relieved to not have to clean the Lewis Gun again for three weeks, but Mainwaring notices that the butterfly spring is missing, and Frazer surmises that it is in his workshop.