Possible Actions: Long delay time. Set for delay firing from 0 to 30 minutes after impact.

DESCRIPTION. Fuze is located centrally in upper longitudinal surface of bomb and is se-cured in bomb by two projections which are held in the grooves in bomb body. Fuze is located in position by two securing strips which fit into the grooves and into the under-cut on the two lugs. The tabs seated in the slots, prevent rotational movement of the fuze when in position.

Over-all dimensions are the same as (41). The fuze consists of three castings, the clock-work mechanism, and the arming rod. The arming rod is similar in all respects to that of the (41) and is operated in exactly the same manner.

Figure 157 is diagrammatic and represents the relative positions of the moving parts of the fuze in the unarmed and fired positions. In the unarmed and fired positions. In the unarmed position the spring loaded striker is held cocked by a projection on the striker cam engaging in a slot in the striker arm. Keyed to this spindle is the striker arm, the other end of which abuts the setting plate cam and thus prevents rotating of the striker cam and release of the striker. Attached to a collar which can rotate independently about the striker cam is a spring  loaded lever arm fitted with an upstand and a clock pin. When the arming spindle is screwed fully home, the clock pin engages with a ballan-ce wheel and thus locks the escapment of the clockwork mechanism.

The fuze is armed when the arming rod has been withdrawn 1/4 inch. The lever arm is then free to move and the clock pin releases the escapement of the clockwork mecha-nism. The movement of the lever arm is limited by means of a stop which also prevents reinsertion of the arming rod.

The main spring of the clockwork mechanism is housed in a casing secured to the reverse side of the plate. One end of the main spring is attached to the casing, and the other ot the boss of the timing disk. Rotation of the timing disk causes a timing stud protruding from it to engage in the slots of the setting plate and rotate the setting plate cam. When this setting plate moves clear of the timing stud as shown in figure 157, a slot in the setting plate cam permits the striker arm to move across thus releasing the striker, which fires a cap and initiates the bomb.

Three rotations of the driving pinion are required to move the setting plate through the full limit of its traverse. Each rotation of the pinion takes approxiymately 10 minutes, ac-cording to the state of tension of the main spring, thus maximum time delay possible is 30 minutes. If the setting plate is disengaged before fuze is armed the fuze will function as soon as the arming rod is withdrawn. By varying the initial positions of the timing stud and setting plate, the fuze can be set to function at any desired time delay from zero to 30 minutes after arming rod is withdrawn.

Figure 157 – (67) Mechanical Clockwork Time Fuze