40. Mechanical-Delay Tilt Assembly

a. Description. The mechanical-delay tilt assembly (fig. 43) contains a spring-loaded slid-ing cylinder with a ball actuation. The mechanical-delay tilt assembly consists of a cylin-drical housing with two mounting screws threaded horizontally into the base ot the as-sembly. The mounting screws are used to clamp the assembly over the case of a pressu-re fuze 35B (par. 24) with the pressure head removed or over an S-mine fuze 35 (par. 25) with the prongs removed. In addition to the spring-loaded sliding cylinder, the me-chanical delay tilt assembly case contains the base of the short tilt rod, the short tilt rod, and a pressure piece which rests on a steel ball supported by two flexible rods sol-dered across a hole in the head of the sliding cylinder (fig. 43).

b. Employment. This mechanical-delay tilt assembly was designed to prevent tanks and tank-mounted clearing devices from opening lanes in mine fields by merely running through the field once.

c. Functioning.

(1)

First stage (arming).

(a)

The first application of pressure on the tilt rod by a tank or vehicle depresses the pressure piece which, in turn, transmits the pressure through the steel ball and its supporting flexible rods to the sliding cylinder. The sliding cylinder is de-pressed against the compression spring until it contacts the base ring. The steel ball is forced through the flexible rods, until it drops on top the pressure head of the fuze. Further pressure has no effect since the steel ball is no lon-ger in contact with the pressure piece.

(b)

When pressure is released after the vehicle has passed, the compression spring has passed, the compression spring returns the sliding cylinder and tilt rod or their original positions, and the increased side clearance allows the balls to roll under the lip of the sliding cylinder. The assembly is now armed (fig. 43).

(2)

Second stage (firing). Any additional pressure against the tilt rod, after the mecha-nical-delay tilt assembly has been armed, is transmitted through the steel ball di-rectly to the pressure head of the fuze, depressing the pressure head and firing the fuze.

d. Installing and Armed.

(1)

Remove the prongs from the S-mine fuze 35 or the pressure cap from a pressure fuze 35B and remove their safety pins.

(2)

Fit the mechanical-delay tilt assembly over the fuze and secure it to the fuze case by tightening the mounting screws.

(3)

Screw this fuze with the attached mechanical-delay tilt assembly into the mine, after inserting a detonator into the fuze well of the mine.

(4)

Carefully attach a slack trip wire to the tilt rod, if desired.

(5)

Cover the mine and mechanical-delay tilt assembly so that only the short tilt rod shows above the ground.

e. Neutralizing.

(1)

Cut the trip wires if any.

(2)

Loosen the mounting screw at the base of the mechanical-delay tilt assembly and lift the assembly carefully off the fuze.

(3)

Insert a nail or other suitable safety pin into the safety-pin hole of the fuze.

(4)

Unscrew the fuze from the mine.

(5)

Remove the percussion cap from the fuze.

Note. In neutralizion the mechanical-delay tilt assembly, be extremely careful not to touch the tilt rod until the assembly is lifted off the fuze. The assembly has no safety device.

Figure 43. Operation of the mechanical-delay tilt assembly.