How Does a Handbrake Work?

An automotive machine is made up of large number of mechanical components which include the chassis, the engine, the steering assembly, the brake assembly and the list is endless. However the most integral part of the vehicle after the engine of the car are the brakes. The brakes play a very important role in reducing the speed of the car so as to make the vehicle come to a hault. The brake assembly of the car is further divided into two segments this include the front brakes and the handbrake.  

The hand brake, also known as the emergency brake, is misinterpreted to be connected by hydraulic means of power transmission, instead it is connected by a metallic cable(with high tension) to the rear wheels, irrespective of the power terrain. This is to avoid catastrophes because of hydraulic brake failure(or pneumatic brakes in case of heavy vehicles). 

It is a latching brake usually used to keep the vehicle stationary. It is sometimes also used to prevent a vehicle from rolling when the operator needs both feet to operate the clutch and throttle pedals. Automobile hand brakes usually consist of a cable directly connected to the brake mechanism on one end and to a lever or foot pedal at the driver's position. The mechanism is often a hand-operated lever, on the floor on either side of the driver , or a pull handle located below and near the steering wheel column, or a (foot-operated) pedal located far apart from the other pedals.

Although sometimes known as an emergency brake, using it in any emergency where the foot-brake is still operational is likely to badly upset the brake balance of the car and vastly increase the likelihood of loss of control of the vehicle. The parking brake operates mostly on the rear wheels, which have reduced traction while braking. The hand brake is basically intended for use in case of mechanical failure where the regular footbrake is inoperable or compromised. Modern brake systems are typically very reliable and equipped with dual-circuit hydraulics and low-brake-fluid sensor systems, meaning the handbrake is rarely used to stop a moving vehicle.

If we open the handbrake lever, a sprocket is found (like the toothed pulley attached to the rear wheel of a bike). Handbrakes are designed in such a manner that, on pulling a lever, the brake shoe(brake pads) is firmly pushed towards the brake drum or disc, thereby holding the wheels. Basically the working of the handbrake is based on Newton’s Third law of motion (each action has an equal and opposite reaction). Brakes tend to act a reactive force, collapsing the lever. This is where the sprocket plays it's role. A pin in the lever is used to lock it with a fixed sprocket. That's the reason we push a button to release the handbrake. And this is how the handbrake of a car works.

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