How a trunk lock works in a car

Boot locks keep the boot or tailgate of a car locked for protection. They differ very little from the locks of car doors and other common locks on vehicles. Most are divided into three different sections: the lock mechanism itself, the emergency trip-lock mechanisms and the automatic release mechanism.

For many years, the lock mechanism worked the same as key-oriented locks for car doors. The main components of these locks are the traditional cylinder and striker: the cylinder holds the tumblers and other mechanisms necessary to unlock the boot, while the striker includes the latch that actually holds the boot shut when locked. Most cars have both the cylinder and the striker located on the lid of the boot, but this does not always hold true--there are many different boot lock designs, and some may separate the cylinder and striker on different parts of the boot. When doors moved to electronic and radio-activated locks that could be operated remotely, trunks were a few years behind. Now many trunks, especially on compact cars, are also opened remotely, and some may not even include a traditional cylinder.

Locks and Emergency Releases

Trunks that still use cylinders generally employ a six- to 10-tumbler mechanism. The more expensive or safety-conscious the car is, the more tumblers the boot will have, although it is common for the boot lock to match the door locks in terms of tumblers, so the same key can open both. Of course, there are also cars that come with boot keys that can only open the boot lock, and vice versa.

The emergency trip device is a simple mechanism located inside the boot, usually in the form of a handle or lever. It opens the boot from the inside even if the boot is fully closed and in the locked position. This is a safety design so that anyone locked in the boot can get out by finding the emergency handle. Some of these devices may be a separate lock that opens to the interior of the car instead.

Automatic Releases

The automatic release mechanism is a feature long included in cars that allows the driver to remotely open the boot while inside the car, usually by pulling a lever. This activates a solenoid, which uses electromagnetic fields to move and operate devices--in this case, the boot lock. Solenoids are also used in the key chain remote systems popular today. The in-car release mechanisms were originally created for efficiency, so that drivers could open trunks before getting out and accessing them, without wasting time using a key to open the lock.