A police lock is a type of high-security

door A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a ''doorway'' or ''portal''. A door's essential and primary purpose is to provide security b ...

lock Lock(s) may refer to: Common meanings *Lock and key, a mechanical device used to secure items of importance *Lock (water navigation), a device for boats to transit between different levels of water, as in a canal Arts and entertainment * ''Lock ...

. There are two distinct kinds of police lock.

Overview

The first is floor-mounted. It consists of a steel bar running on at a roughly 45° angle from the center of the door to the floor, on the inside of the area to be secured. At each end of the bar are slots or fixtures (one in the door, one in the floor) into which the steel bar is secured. This was designed by Emiel Fox (born 1869 or 1870, died 1941). Patents relating to early versions of the lock go back to at least 1907. Fox set up the Fox Police Lock Company in

New York City New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the U ...

to manufacture the locks under the brand name Police Lock; other companies have made similar locks under the same designation, so the term has become genericized to a degree. The name comes from the police procedure for securing a damaged door, which uses a similarly angled piece of sturdy wood nailed in place. This type of police lock provides considerable security since it is even harder to break with physical force than a

deadbolt A dead bolt, deadbolt or dead lock is a locking mechanism distinct from a spring bolt lock because a deadbolt can only be opened by a key or handle. The more common spring bolt lock uses a spring to hold the bolt in place, allowing retraction ...

– to defeat this kind of lock, the door must be at least partially destroyed or removed from its frame. Another type of lock also called a police lock and also formerly made by the Fox Police Lock Company is the crossbar police lock. It features two steel bars across the width of the door and beyond, held by two brackets set in the

doorframe A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a ''doorway'' or ''portal''. A door's essential and primary purpose is to provide security b ...

. When the door is unlocked, the bars are moved inwards to the point of being withdrawn from the brackets. Police locks are particularly associated with

in the 20th century, and are sometimes seen in movies set in that place and time. Floor-mounted types were designed for use with wooden doors and have been superseded with the advent of metal doors and doorframes. A copy of the original crossbar type of police lock is still made and imported from China.

References

{{reflist, refs= {{cite web , url=https://www.nytimes.com/2008/04/27/nyregion/thecity/27lock.html , title=When the Deadbolt Was Not Enough , author=Gregory Byer , date=April 27, 2008 , work=New York Times , accessdate=December 11, 2014 {{cite web , url=https://www.nytimes.com/1998/10/11/nyregion/fyi-250147.html , title=F.Y.I - Still Barring the Door , author=Daniel B. Schnieder , date=October 11, 1998 , work=New York Times , accessdate=December 11, 2014 {{cite web , url=http://www.nokey.com/foxstylpollo.html , title=Fox Police Lock (Original Style) , work=NoKey.com, accessdate=December 11, 2014 Locks (security device) American inventions 20th century in New York City