BELLOWS

DEPTH SETTING SLEEVE

10. The depth-setting sleeve, which is attached to the index pointer and is free to ro-tate but not to move axially along the piston stem, is threaded internally to match ex-ternal threads on the adjusting bushing. The bushing is keyed to the piston stem so that the bushing cannot rotate. Thus rotation of the depth-setting sleeve will move the ad-justing bushing along the axis of the piston stem. The depth-setting spring is housed in-side the adjusting bushing, between the inner end of the bushing and the collar on the piston rod. Therefore the position of the depth-setting bushing determines the distance the pistoon stem collar can move before it takes up against the depth-setting spring and the amount that this spring must be compressed before the striker is released.

Blue indicates exterior - Red indicates interior

GUIDE TUBE

11. A guide tube is secured to the inner end of the pistol casing. The inner end of the piston stem, which houses a firing spring, is free to slide inside this tube. The inner end of the firing spring fits around a shoulder on the firing plunger. The plunger, in turn, fits inside a bushing secured in the guide tube. A release plunger is installed inside the firing plunger, with a spring between it and a firing point which is secured to the inner end of the firing plunger.

LOCKING BALLS

12. Hardened balls fitted in the firing plunger lock the plunger and firing point away from the detonator. The detonator is secured in the inner end of the guide tube. A flange is fastened to the inner end of the guide tube to center the pistol assembly in the central tube of the depth charge case. It also provides a flat surface against which the booster can rests when the booster-extender is in the armed position.