56. 5-Minute Clockwork Delay Fuzes (Zeitzünder für F; Zeitzünder für Sprüh Büchse 37)

a. Description. Three types of the five-minute clockwork delay fuzes exist (figs. 56, 57 and 58). They are all similar. The fuze is a delay, mechanical type containing a spring-loaded striker with a clockwork release. It consists of a simple clockwork mechanism hou-sed in a cylindrical bakelite case. The fuze has a time indicator, graduated in minutes, on the front and a winding post in the lack. The time indicator can be turned to any of the desired number of minutes, up to 5. A safety pin, when in place, prevents the mechanism from running. A threaded bakelite cap permits access to the mechanism.

Figure 56. 5-minute clockwork delay fuze type I.

(1)

Type I and II. The type I (fig. 56) and type II (fig. 57) fuzes are 3 inches long and 1 1/2 inches in diameter. Both types have a winding key carried in a recess in the top of the threaded bakelite cap. The only differences between the two fuzes are that type I has its setting dial outside the case and has a double-looped safety pin. Type II has a setting dial inside the case, a circular glass window for viewing the dial, and a single-looped safety pin. Type I has the letters Zt.Z. f. F. on the front below the dial, and type II has the letters Zt.Z. f. Sp.Bu. 37 below the glass set-ting window. Both of these types have standard bases.

Figure 57. 5-minute clockwork delay fuze type II.

(2)

Type III. The type III fuze (fig. 58) is longer than types I and II, measu ring 4 1/2 inches in length and 1 5/8 inches in diameter. The type III has an arming knob in the top of the fuze which can be turned to either scharf (armed) or sicher (safety). A safety pin prevents the shaft of the arming knot from turning and also prevents the striker shaft from moving. The base of the fuze does not have the standard-thread adapter, but has instead a spring clip on each side of the fuze to hold the fuze in the charge. An aluminum detonator holder screws into the base of the fuze. The winding key for this fuze is not attached to the fuze as in type I and II.

Figure 58. 5-minute clockwork delay fuze, type III.

b. Employment. The 5-minute clockwork delay fuzes are used in the bounding gas mine 37 (par. 100), and in sabotage work.

c. Functioning. The spring-laoded is attached to the clockwork mechanism by a hinged arm which also holds the striker in a cocked position. As clockwork unwinds, the hinged arm as pushed aside by a slowly revolving cam. At the end of the set delay, the striker is released, firing the detonator.

d. Installing and Arming.

(1)

Wind the clockwork with the winding key and set the dial at the standard delay in minutes.

(2)

Insert the fuze into the charge.

(3)

Remove the safety-pin-retaining wire and pull the safety pin out tof the fuze. This starts the clockwork mechanism. In type III set the arming knob at scharf.

e. Neutralizing.

(1)

For types I and II, insert a wire or nail into the safety-pin hole. For type III, turn the arming dial to sicher and then insert a safety pin.

(2)

Remove the fuze from the charge.