FUZE 117 MK-20

ROLE :
Fuze 117 is a direct action and graze fuze. It is used in a variety of equipment, with HE, bursting smoke and chemical shells. It functions at low angle of impact and is rapid in action.

FUNCTION :
Before loading, the safety cap is removed but not striker cover.

ON FIRING –

a.	Acceleration of shell causes the arming sleeve to set back due to its inertia compressing the arming spring and the four segments, and thus freed, slips & flys off, aided by the action of the centrifugal force.
b.	The striker sets back slightly compressing its spring and holds the locking weight in closed position with its points engaged in recess.
c.	The shutter & the locking weight is held in the closed position by the friction caused by their setback on the top of the magazine.

DURING FLIGHT –

a.	The setback ceases & striker spring then asserts itself & carries the striker forward, until the striker sleeve meets the guide bush thus withdrawing the point of striker from the recess in the locking weight.
b.	The friction is reduced & centrifugal force causes the locking weight to swing outwards, there by releasing the shutter which swings in to the open position. The detonator in the shutter is now under the striker & over the C.E.stemmed channel of the magazine.

ON IMPACT –
The striker is forced in, compressing the striker spring, the point pierces the detonator & resulting detonating impulse passes through the explosive stemmed channel to the explosive pellet in the magazine & thereafter to the bursting charge of the shell.

SPECIFICATION / CHARACTERISTICS / TECHNICAL DATA –

Mass of Filled Fuze	1.188 Kg ± 10 gms.
Length of fuze	124.689 mm to 126.848 mm

QUALITY-
At every stage of processing, strict quality control measures are adopted to ensure the high quality of the fuzes.

SAFETY-

a.	The safety cap protects the striker cover and striker, thus preventing accidental damage and firing during storage and transport. The striker cover protects the striker head from air resistance during flight – thus preventing premature arming.
b.	The segment held in position by the arming sleeve and arming spring, acting through the striker sleeve hold the striker in position in the locking weight.
c.	The shutter opens between 2200 to 3000 rpm and is held in closed position by the locking weight in conjunction with the point of striker.

PACKING –

Container 47B is used for packing of fuze
Box M104 is used to hold 20 fuzes

HAZARD CLASSIFICATION

Compatibility Group	B
Hazard Division	1.2
Fire Flighting Classification	2