Safety Devices

1
Safety Devices

• Have a look to see how safety Devices work.

2
How Air Bags Work.

• AIR BAGS are among the most important safety
  improvements added to cars and light trucks in
  recent years, providing extra protection for
  front-seat occupants in head-on crashes. They're
  now standard equipment in the U.S., and over 90
  million air bag-equipped vehicles are on the road
  today.
•         how air bags work -- a quick look at the
  technology and components of this high-tech
  safety system
•          their safety record so far -- the
  positive performance overall, but risks to
  children and short-statured adults
•          new warning labels for vehicles and
  child seats, warning of the risk to children
  sitting in the front seat of an air bag-equipped
  car

3
Facts About Airbags.

• Air bags can save YOUR LIFE.
• Air bags can KILL your Childs life.
• The children can be saved by sitting in the back
  passenger seats.
• They can accidentally be set off with a slight
  bump.

4
Crumple Devices.

• Now you will find out some information on crumple
  devices.

5
Crumple Devices

•   . In figure 1, a steel block travels at a
  constant velocity towards a cement wall,
  representing an automobile without crumple zones.
  Initially, the block has kinetic energy,
  represented by the expression, mv2/r. As the
  block collides with the wall, it exerts a force
  on the wall, after which the wall exerts an equal
  and opposite force on the block. The magnitude of
  this force is illustrated by the amount of
  kinetic energy regained by the block. At the
  moment of impact, the steel block immediately
  rebounds in an elastic manner, regaining nearly
  all of its kinetic energy, and consequently
  experiencing a large force.

6
What is a crumple zone.

•     In recent years, the automobile industry has
  attempted to improve safety through a number of
  technological developments. One technique which
  has been proven to be successful, involves the
  use of crumple zones positioned in specific areas
  of an automobile. Crumple zones are created by
  the integration of variable grades of steel and
  fiberglass into the front and rear-end assemblies
  of the automobile.  Occasionally, crumple zones
  are used in the actual frame of the automobile,
  creating a point for the frame to buckle when
  subjected to extreme stress. 

.
7
Seat Belts.

• This is going to look at seat belts and how they
  work.

8
Seat Belts.

•                 The most dramatic effects have
  followed the use of seat belts and child
  restraints in cars. Use of seat belts reduces the
  risk of death or serious injury by about 45 per
  cent. Publicity has played a major part in
  increasing wearing rates, but for full effect it
  needs to be backed by legislation. Legislation
  for compulsory wearing was first introduced in
  the State of Victoria, Australia in 1971. Today
  all the major developed countries of the world
  have laws enforcing the wearing of seat belts,
  with reported levels of compliance of over 90 per
  cent in some countries, notably for front-seat
  passengers in the United Kingdom. Other
  protective measures that are gaining support are
  the wearing of helmets by cyclists (again led by
  the example of Victoria), and the use of crash
  protection barriers on the central reserve of
  high-speed motorways, and to guard rigid objects
  on the roadside (utility poles, sign supports,
  bridge abutments, and trees). Many advances have
  been made in vehicle design to protect occupants
  there is also potential for greater protection
  for the vulnerable pedestrians and cyclists who
  come into contact with motor vehicles, but
  promising developments have not yet been fully
  exploited.
•  

9
Facts on seat belts.

• Seat belts are elastic to absorb energy
• After this has been used in an accident they have
  to be replaced.
• If seat belts werent elastic it would slice you
  in half in a crash incident.

10
Braking system.

• The braking system of a car.

11
Brakes.

• The force required to press a brake shoe against
  a brake drum may be great, especially for a heavy
  vehicle moving at high speeds. This force may be
  generated by hand, as in the emergency, or
  parking, brake on a motor car. Usually, however,
  human force is boosted by an air-operated piston
  and cylinder (air brake) or a vacuum-operated
  piston (vacuum-assist, or power, brake). In the
  air brake, which was invented by George
  Westinghouse in 1869, the shoe and drum are kept
  apart by air pressure while the vehicle is in
  motion. When the pressure is released, the brakes
  are applied. This method eliminates the danger of
  brake failure because of air leakage if the
  compressed air system leaks, the brakes are
  automatically applied. All railway trains and
  some heavy goods vehicles, particularly trailer
  lorries, use air brakes.
• Cars were originally equipped with nonhydraulic
  brakes, applied to the rear wheels only.
  Four-wheel brakes were generally adopted during
  the 1920s for additional safety. In mechanical
  brakes, slight wear in one of the brake levers
  might cause swerving of a vehicle through uneven
  application of braking force. Hydraulic
  four-wheel brakes, which are now used on almost
  all cars and many lorries, are automatically
  self-aligning. When the driver presses the brake
  pedal, hydraulic fluid is sent from the master
  cylinder to all the brake shoes with the same
  pressure, and the same braking force is applied
  to each wheel.