Automatic deadlocking
feature on a latch which prevents the latch tongue from being pushed back
whilst the door is still closed (the credit card trick, often seen in the
movies, but actually pretty hard to do!)
Backplate
plate on which the moving parts of a handle or knob are mounted.
Backset
the distance from the door edge to the centre of the keyhole or handle.
Bathroom Lock
a lock fitted to an internal door which has both a spring latch operated
by a handle or knob from either side, and a privacy bolt operated by a
small thumb turn. The thumb turn has a small knob on the inside which can be
turned by hand and an emergency release slot on the outside. The emergency
release is designed to be turned with a coin.
Cabinet Lock
a term covering locks of any type used on furniture, such as cupboards,
drawers, chests and boxes.
Case
the metal body of a lock or latch containing the mechanism.
Centres
the vertical distance between the centre of the keyhole and the hole for the
handle spindle.
Claw Bolt
a type of lock, fitted to sliding doors, having a bolt with pivoting claws
which swing out sideways when locked.
Closed Shackle
a padlock where the shackle is partially hidden by the shape of the lock
body - provides resistance against forcing or use of bolt-croppers.
Deadlatch
a latch, either rim type or mortice type, which secures the door closed, but
can be withdrawn by key from outside and by knob or handle from inside.
Latch tongue cannot be pushed back (credit card trick) once the door is
shut. See also Nightlatch
Deadlock
standard mortice lock, set into the edge of a door, with a square-ended bolt
operated by key or, occasionally, by a thumb turn on the inside.
Deadlocking
facility in a rim lock which, using an extra turn of the key on the outside,
prevents the latch or bolt from being operated when the door is closed (see
also Automatic Deadlocking).
Escutcheon
the surround plate for a keyhole.
Espagnolette bolt
espagnolette bolts work by turning a knob or lever which shoots
bolts into staples or plates on the frame and floor, subsequently bolting the
door. Usually the bolts are quite long, often running from the door handle up to
the top and down to the bottom of the door. They might have either a lever or
knob as a handle, with the most common option an oval knob. Some types
are lockable and are suitable for secure closing of external double doors.
Euro profile handle
Euro profile handles have an enlarged key hole shape cut out of the
back plate. This euro cut out in the back plate is used to house a key operated
cylinder. The cylinder is used with a mortice sash lock fitted into the edge of
the door which also has the euro shape cut into it to allow the cylinder to pass
through the lock and come out on the opposite side of the door. These cylinders
come in various styles such as double key, key and turn, or single cylinder.
Follower
part of the latch mechanism that contains a square hole, through which the
square spindle for the handle sits. Turning the follower moves the latch
tongue.
Forend
the face of the lock or latch, seen in the door edge, through which the bolt
or latch tongue protrudes.
Hand
refers to the direction of opening a door and, consequently, which way the
bevelled latch must slope in order to operate.
Keep
term sometimes used for the striking plate fitted to the door frame which
accepts the lock bolt or latch tongue.
Latch
a spring-loaded tongue which secures the door closed, but is not lockable.
Certain types have now been adapted to lock as well
Lever
part inside a lock, moved by the key, which allows the lock to be operated.
Generally, more levers means higher security. Most insurance companies now
require a 5 lever lock to be fitted to all external doors.
Lever handle
a horizontal handle for operating the latch mechanism. The handles are
usually spring-loaded to ensure return to horizontal position after use.
Some foreign handles (NOT the ones we sell!) are un-sprung - but this is not
a problem as the latch just needs a stronger spring instead.
Lever lock handle
the same as a lever handle but with a keyhole cut into the backplate to
allow for a mortise sash lock to be fitted so that the door can be locked.
Note that the locks come in different sizes so the correct size and fitting
is needed to ensure that the keyhole lines up with the lock.
Lever on rose
Door handles normally have a recangular backplate which screws to the door, and
sometimes has a keyhole in it. However its possible to get a handle on a small round
backplate with just two screws and no space for a keyhole. This is a Lever On Rose
and it won't allow for a keyhole, unless you fit an Escutcheon.
Mortice
a recess cut into the edge of a door to receive a mortice lock or latch.
Nightlatch
a latch, either rim type or mortice type, which secures the door closed, but
can be withdrawn by key from outside and by knob or handle from inside.
Often has a 'snib' to hold the latch back if required. Not very secure
(credit card trick!) and can simply be opened from the inside unless either
deadlocked from the outside (extra turn of the key) or using a locking
handle (if fitted) on the inside.
Pass
a key that operates a lock is said to 'pass' the lock. If locks are made
'keyed alike' then one key will 'pass' all the locks.
Pin Tumbler Lock
type of cylinder mechanism found on most rim locks. The cylinder contains a
line of small pins which, when the correct key lifts the pins to the correct
position, allows the cylinder to turn. When the cylinder is rotated the lock
is operated.
Rim Lock or Latch
a lock or latch which is fitted on to the inside face/edge of a door.
Roller Bolt
found in some latches instead of a spring loaded tongue, a bolt made with
rollers to engage into the latchplate. Works with either door swing or
'hand'.
Rose
circular plate on which the moving parts of a handle or knob are mounted.
Sashlock
a mortice lock containing both a) a latch operated by handles and b) a bolt
secured by key.
Snib
a small button/switch on the case of a nightlatch used to hold the latch
tongue back or, alternatively, to stop the latch being operated when closed.
Spindle
the square bar inserted through a latch which connects the handles on either
side of the door.
Striking Plate (latchplate)
plate fixed to the door frame with one or more bolt holes, into which the
bolt or latch shoots. There is often a shaped projecting lip on one side to
guide the latch tongue.
Suite
locks can be grouped into sets that can then be operated by a controlled
distribution of keys. The number of suites is virtually unlimited and can be
operated under a Master Key system.