Glossary - R

rabbet (n)
(see "rebate")

rack and pinion (adj)
having a mechanism which uses a rack and pinion to produce a power curve that is suitable only for scissor-arm door closers

rack bolt (np)
(see "mortice rack bolt")

racking (n)
in-plane parallelogram distortion of a sash or casement

racking / racking slot (n/np)
(see "pocket")

radiusing (of a key bit) (n)
curvature on a key step corresponding to its true radius from the key pin centre

rated supply voltage (np)
nominal voltage for which a device is intended (see also prEN 14846, EN 1155, prEN 13633 & prEN 13637)

read (v)
determine the combination of a lock by visual means

rebate (n)
step in a frame (or adjacent leaf) which provides the stop for the leaf

rebated lock (np)
lock adapted to mount on the rebated edge of a leaf

release force (np)
(Product specific term - see EN 179 & EN 1125)

release moment (np)
torque required to manually release a door or window from any hold-open position (see also EN 1155)

remote activation (np)
(Product specific term - see prEN 12650)

requesting element (np)
(Product specific term - see prEN 13637)

restricted opening device (np)
hardware, or part of hardware which, for reasons of safety, limits the initial opening of a sash or casement to a pre-determined position (now same as CEN/TS 13126-5)

resulting projection (np)
projection after the application of end load (see also EN 12051)

retractable guide bolt (np)
flush bolt with a roller on the end of the shoot which can be withdrawn to remove the door leaf from the track

reversible bolt (np)
bolt for which the closing direction (clockwise or anti-clockwise) can be altered without dismantling

revolving door (np)
door with two or more leaves pivoted about a common vertical axis and contained within an enclosure (see also prEN 12650)

right hand door (np)
door which opens in an anti-clockwise direction when viewed from above

right hand sliding door
sliding door of a single sliding door assembly which moves right to open when viewed from the sliding door side

right hand swing door
swing door which opens in an anti-clockwise direction when viewed from above

rim cylinder (np)
cylinder for use with a rim lock or latch, and which is adapted for flush (or near flush) mounting within a leaf

rim deadlock (np)
deadlock adapted for surface mounting on the face of a leaf

rim latch (np)
latch adapted for surface mounting on the face of a leaf

rim lock (np)
lock adapted for surface mounting on the face of a leaf (see also WI 33/250)

rim night latch (np)
night latch adapted for surface mounting on the face of a door leaf

rising butt hinge (np)
butt hinge with cam action knuckles to cause leaf to rise as it is opened

roll (n)
(Product specific term - see CEN/TS 13126)

roller ¹ (n)
(see "top pin")

roller ² (n)
(Product specific term - see CEN/TS 13126)

roller ³ (n)
moving element of a multipoint lock which projects from the forend and engages a ramped surface on the frame during locking, for the purpose of clenching

roller bolt (np)
latch bolt with rotating feature in the head to facilitate withdrawal of the bolt upon engagement with the striking plate

roller catch (np)
push-pull fastener comprising a spring loaded roller

rose ¹ (n)
circular mounting plate for individual lever handle or knob (see also EN 1906)

rose ² (n)
(see "cylinder rose")

rounded forend / round end forend (np)
forend with semi-circular ends