History of the Automobile Brake System

Newton determined that an object in motion will stay in motion unless acted on by a force. When an automobile is in motion, a force has to be applied to stop its motion. This stopping action is accomplished by the braking system. Like many technologies, automobile brakes have been improved upon and have developed over the years. Although the goal of stopping the car remains the same, the method by which this is accomplished is more advanced today.

Wooden Block Brake

The first braking systems involved a lever and a block of wood. This system was used for automobiles with steel rimmed wheels. The driver would pull on a lever which would press a block of wood against the wheels, slowing the car. This system was efficient and worked well, but was no longer workable when the rubber tire was introduced. At that point, some other type of braking system had to be explored.

Mechanical Drum Brake

In the early 1900s, the mechanical drum brake was introduced. This brake system involved a "single flexible stainless-steel band, wrapped around a drum on the rear axle".When the driver engaged the brake, the band would apply pressure to the drum and the car would stop. The first drum brakes were external. This was a problem because they were exposed to the elements and did not last very long. Brakes had to be replaced fairly often. The band would also often unwrap on hills. This issue was addressed by putting the brake shoes, the part that applied the pressure to slow the car, inside of the drum.

Hydraulic Drum Brake

In 1918 the hydraulic drum brake was invented by Malcolm Lougheed. This system uses hydraulic fluid to apply the pressure to stop the car. When the driver engages the brake, hydraulic fluid is pushed through a series of tubes to the brake drum. This fluid pushes the brakes shoes against the drum's interior linings. This would then slow the car. Drum breaks are still in use today and their design has just been enhanced over time. However, the biggest difficulty with drum brakes is the heat. The heat builds up and does not have a way to dissipate, thus eventually warping the brake and causing vibration.

Disc Brake

Another technology that was patented in the early 1900s was the disc brake. Disc brakes are made from iron. These discs are "'squeezed' by the braking pads to bring the vehicle to a halt. These brake pads are squeezed by a caliper which is pressured by the hydraulic fluid. Initially the brake pads did not have any lining. When the two pieces of metal came in contact, there was a terrible noise. Asbestos was used for lining in both disc braking systems and drum braking systems, and this substantially helped improve performance.

Anti-Lock Brakes (ABS)

A modification to braking systems, anti-lock brakes is a safety feature which helps prevent the brakes from locking up. Speed sensors in the car help to determine if a wheel is going to lock up. Then a series of hydraulic valves limit or reduce the braking on that wheel. This enables to driver to maintain control of the car and it prevents the car from going into a spin.