Power door locks
Encyclopedia
Power door locks allow the driver or front passenger to simultaneously lock or unlock all the doors of an automobile
or truck
, by pressing a button or flipping a switch
.
Power door locks were introduced on the luxury Scripps-Booth
in 1914, but were not common on luxury cars until Packard
reintroduced them in 1956. Nearly every car model today offers this feature as at least optional equipment.
Early systems locked and unlocked only the car doors
. Many cars today also feature systems which can unlock such things as the luggage compartment or fuel filler cap door.
It is also common on modern cars for the locks to activate automatically when the car is put into gear or reaches a certain speed. Automatic unlocking when the car is parked is usually also featured on such systems.
Today, many cars with power door locks also have a radio frequency remote keyless system
, which allows a person to press a button on a remote control
key fob.
In 1980, Ford Motor Company
introduced an external keypad
-type keyless entry system, wherein the driver entered a numeric combination -- either pre-programmed at the factory or one programmed by the owner -- to unlock the car without the key. Early- to mid-1980s Nissan Maxima
s could also be installed with a keypad, which would also retract the windows and moonroof once the car was successfully unlocked by pushing a specific button on the keypad.
Currently, many luxury makers also allow the windows to be opened or closed by pressing and holding a button on the remote control key fob, or by inserting the ignition key and holding it in the lock or unlock position in the external driver's door lock. During the early 1990s, Subaru offered infra-red keyless entry on the Japanese Domestic Market Legacy, installing the transmitter in the ignition key. The Legacy could also be opened by pulling the drivers external door handle a specific number of times to enter a passcode number that would unlock the driver's door only.
This system confirms successful (un)locking through either a light or a horn signal, and usually offers an option to switch easily between these two variants. Both provide almost the same functionality, though light signals are more discreet while horn signals might create a nuisance in residential neighborhoods and other busy parking areas (e.g. short-term parking lots). Some manufacturers offer the ability to adjust the horn signal volume.
Other cars have a proximity system that is triggered if a keylike transducer
(Advanced Key
or handsfree) is within a certain distance
of the car.
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
or truck
Truck
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
, by pressing a button or flipping a switch
Switch
In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....
.
Power door locks were introduced on the luxury Scripps-Booth
Scripps-Booth
Scripps-Booth was a United States automobile company based in Detroit, Michigan, which produced motor vehicles from 1913 through 1923.-History:...
in 1914, but were not common on luxury cars until Packard
Packard
Packard was an American luxury-type automobile marque built by the Packard Motor Car Company of Detroit, Michigan, and later by the Studebaker-Packard Corporation of South Bend, Indiana...
reintroduced them in 1956. Nearly every car model today offers this feature as at least optional equipment.
Early systems locked and unlocked only the car doors
Vehicle door
A vehicle door is a partition, typically hinged, but sometimes attached by other mechanisms such as tracks, in front of an opening which is used for entering and exiting a vehicle. A vehicle door can be opened to provide access to the opening, or closed to secure it. These doors are similar to...
. Many cars today also feature systems which can unlock such things as the luggage compartment or fuel filler cap door.
It is also common on modern cars for the locks to activate automatically when the car is put into gear or reaches a certain speed. Automatic unlocking when the car is parked is usually also featured on such systems.
Remote and handsfree
Remote keyless system
A remote keyless system is a system designed to permit or deny access to premises or automobiles. While the "remote" system is portable and has locking capabilities, the exact phrase "keyless entry" is solely reserved for the numeric dials or keypads that are located on or near the driver side door...
, which allows a person to press a button on a remote control
Remote control
A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...
key fob.
In 1980, Ford Motor Company
Ford Motor Company
Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...
introduced an external keypad
Combination lock
A combination lock is a type of lock in which a sequence of numbers or symbols is used to open the lock. The sequence may be entered using a single rotating dial which interacts with several discs or cams, by using a set of several rotating discs with inscribed numerals which directly interact with...
-type keyless entry system, wherein the driver entered a numeric combination -- either pre-programmed at the factory or one programmed by the owner -- to unlock the car without the key. Early- to mid-1980s Nissan Maxima
Nissan Maxima
The first car to wear the Maxima name was introduced in 1981. It was essentially a Japanese-market Bluebird 910 with a longer nose. The car was offered as the 810 Deluxe or 810 Maxima that first year, and all 810s became Maximas for 1982...
s could also be installed with a keypad, which would also retract the windows and moonroof once the car was successfully unlocked by pushing a specific button on the keypad.
Currently, many luxury makers also allow the windows to be opened or closed by pressing and holding a button on the remote control key fob, or by inserting the ignition key and holding it in the lock or unlock position in the external driver's door lock. During the early 1990s, Subaru offered infra-red keyless entry on the Japanese Domestic Market Legacy, installing the transmitter in the ignition key. The Legacy could also be opened by pulling the drivers external door handle a specific number of times to enter a passcode number that would unlock the driver's door only.
This system confirms successful (un)locking through either a light or a horn signal, and usually offers an option to switch easily between these two variants. Both provide almost the same functionality, though light signals are more discreet while horn signals might create a nuisance in residential neighborhoods and other busy parking areas (e.g. short-term parking lots). Some manufacturers offer the ability to adjust the horn signal volume.
Other cars have a proximity system that is triggered if a keylike transducer
Transducer
A transducer is a device that converts one type of energy to another. Energy types include electrical, mechanical, electromagnetic , chemical, acoustic or thermal energy. While the term transducer commonly implies the use of a sensor/detector, any device which converts energy can be considered a...
(Advanced Key
Advanced Key
Smart key is an electronic access and authorization system which is available as an option or standard in several cars. It was first used by Mercedes-Benz in 1998.-How it works:...
or handsfree) is within a certain distance
Distance
Distance is a numerical description of how far apart objects are. In physics or everyday discussion, distance may refer to a physical length, or an estimation based on other criteria . In mathematics, a distance function or metric is a generalization of the concept of physical distance...
of the car.
See also
- Automobile ancillary powerAutomobile ancillary power]Automobile accessory power can be transferred by several different means. However, it is always ultimately derived from the automobile's internal combustion engine, battery, or other "prime mover" source of energy...
- Child safety lockChild safety lockA child safety lock is a special-purpose lock for cabinets, drawers, bottles, etc. that is designed to help prevent children from getting at any dangerous contents. Young children are naturally curious about their surroundings and will always explore, but as they may be unaware of dangerous...
- Power seatPower seatA power seat in an automobile is a front seat which can be adjusted by using a switch or joystick and a set of small electric motors. Most cars with this feature have controls for the driver's seat only, though almost all luxury cars also have power controls for the front passenger seat.In addition...
- Power windowPower windowPower windows or electric windows as well as electric or power window lifts are automobile windows which can be raised and lowered by depressing a button or switch, as opposed to using a hand-turned crank handle.- History :Packard introduced the first power windows in the 1940 Packard...
s - Remote keyless systemRemote keyless systemA remote keyless system is a system designed to permit or deny access to premises or automobiles. While the "remote" system is portable and has locking capabilities, the exact phrase "keyless entry" is solely reserved for the numeric dials or keypads that are located on or near the driver side door...
- Window locking