Innovatize

Seat belt is very essential component in any vehicle regarding our safety; it holds us at time of any accident. Prevent us to strike against steering and dashboard. 

Let us understand how it works.

Standard seat belts have a retractor mechanism.

The belt webbing is connected to retractor mechanism.

The central element in retractor is spool. The central element in the retractor is a spool, which is attached to one end of the webbing. Inside the retractor, a spring applies a rotation force, or torque, to the spool. This works to rotate the spool so it winds up any loose webbing.

When you pull the webbing out, the spool rotates counter-clockwise, which turns the attached spring in the same direction. Effectively, the rotating spool works to untwist the spring. The spring wants to return to its original shape, so it resists this twisting motion. If you release the webbing, the spring will tighten up, rotating the spool clockwise until there is no more slack in the belt.

There are two sorts of locking systems in common use today:

                Involve car movement to pull over.

The central operating element in this mechanism is a weighted pendulum. When the car comes to a sudden stop, the inertia causes the pendulum to swing forward. The pawl on the other end of the pendulum catches hold of a toothed ratchet gear attached to the spool. With the pawl gripping one of its teeth, the gear can't rotate counter-clockwise, and neither can the connected spool. When the webbing loosens again after the crash, the gear rotates clockwise and the pawl disengages.

Involve belt movement to pull over.

The second kind of system locks the spool when something jerks the belt webbing. The activating force in most designs is the speed of the spool rotation.

The central operating element in this design is a centrifugal clutch -- a weighted pivoting lever mounted to the rotating spool. When the spool spins slowly, the lever doesn't pivot at all. A spring keeps it in position. But when something yanks the webbing, spinning the spool more quickly, centrifugal force drives the weighted end of the lever outward.

The extended lever pushes a cam piece mounted to the retractor housing. The cam is connected to a pivoting pawl by a sliding pin. As the cam shifts to the left, the pin moves along a groove in the pawl. This pulls the pawl into the spinning ratchet gear attached to the spool. The pawl locks into the gear's teeth, preventing counter-clockwise rotation.

Types of belt:

Lap:- A lap belt is a strap that goes over the waist. This was the most commonly installed type of belt prior to legislation requiring 3-point belts, and is primarily found in older cars. Coaches are equipped with lap belts, as are passenger aircraft seats.

Sash:- A "sash" or shoulder harness is a strap that goes diagonally over the vehicle occupant's outboard shoulder and is buckled inboard of his or her lap.

Three-point

A 3-point belt is a Y-shaped arrangement, similar to the separate lap and sash belts, but unitized. Like the separate lap-and-sash belt, in a collision the 3-point belt spreads out the energy of the moving body over the chest, pelvis, and shoulders.

4-, 5-, and 6-point

Five-point harnesses are typically found in child safety seats and in racing cars. The lap portion is connected to a belt between the legs and there are two shoulder belts, making a total of five points of attachment to the seat.