SUM 6 - Fuzes Flashcards
(35 cards)
What is the definition of a fuse?
A fuse is a device designed to function an item of ammunition under pre determined circumstances
Fuses are classified according to what three categories?
Filling
Position
Function
Define the following:
PD
BD
PIBD
T
CT
MT
VT
CVT
SQ
DLY
MTSQ
TSQ
PDSQ
MO
ET
Point Detonating
Base Detonating
Point Initiating Base Detonating
Time
Combustion Time
Mech Time
Variable Time
Controlled Variable Time
Super Quick
Delay
Mech Time Super Quick
Time Super Quick
Point Detonating Super Quick
Multi Option
Electronic Time
What are the two requirements of a fuse?
Safety - for storage and transport
- against pre mature function
Reliability - function when required
One of the other requirements of a fuse is that it fits the fuse cavity, name five more?
Standard weight
Optional delay setting
Multi role to minimise refusing
Minimum preparation for use
Easy time adjust setting
One mechanical device is a Shutter, name three more.
Delay arming shutter
Masking
Horse head segments
Bore riding pin
Centrifugal balls
Explain when a fuse is armed.
A fuse is armed when it has gone through all of it’s firing forces and the explosive train is inline..
Explain the following:
Setback
Stored energy
Creep forward
Centrifugal force
Set forward
Spin decay
Air/gas pressure
Setback - Rapid acceleration forcing momentum rearwards
Stored energy - energy ready to be released (spring under tension)
Creep forward - After setback and the momentum starts to decelerate, moving parts return to a forward position
Centrifugal force - momentum moves outwards due to a rapid spinning motion
Set forward - violent deceleration on impact
Spin decay - decrease in angular velocity
Air/gas pressure - used to drive a turbine to generate power in electrically operated fuses
What are the four Impact fuse actions?
Super quick
Non delay
Graze
Delay
What are the categories of impact fuses?
PD
BD
PIBD
How does graze sensitive work?
Functioned when checked in flight or receives appreciable deceleration, a movable part called the graze or inertia pellet moves forward to carry the detonator on to the needle or vice versa. A creep spring keeps the two apart. The detonator is a flash type and the fuse has a small delay
What are boosters made of and what are they for?
CE pellet
Carries the explosive wave from the detonator and transfers it to the main fill
What are the three types of time fuses?
Combustion time
Mechanical time
Electronic time
What are the three types of mechanical time fuses?
Dixi - Swiss fuze
Junghans - American MT Fuzes
Thiel - British MT Fuzes
Describe the Doppler effect.
-Radio waves are emitted by the fuze, some of the
waves are reflected and picked up by the receiver
- The time taken to return affects the Reflected waves,
which interfere with the radiated waves to give a beat
known as the Doppler effect - As the fuze gets closer to the set target distance the
impulses increase to a defined peak value and the
fuze functions
What are some design considerations for prox fuses?
Rugged
Economical
Light weight
Able to fit in existing projectiles
Not easily jammed
Sensitive and rapid in operation
What are the standard cavity types for fuzes?
Mortar - 1.5inch
Arty - 2inch
What is a bore riding pin?
A pin that rides inside the bore and wehn the item leaves the bore, the pin ejects which aligns the explosive train
What is an inertia pellet?
A heavy weight that carries the detonator on rapid deceleration into the firing pin
What are some safety features of mech fuzes?
cannot be assembled in unsafe condition. can be checked suring and after assembly
What are some advantages of elec time fuzes?
low cost due to multi role function
Versatility in arming
What is the difference between vt and CVT?
VT has no setting for optimum height
Requirements classification safety of fuzes
- Battery is inert until ampoule is broken.
- Clockwork mechanism prevents signal
- Shutter or S & A mechanism keeps
- Electric components can be short circuited until safe to arm has operated as intended.
Influence fuze
