Locking device

A leaf assembly comprising a door leaf and a frame, the leaf being pivotally mounted in the frame, the leaf having a leading face, a trailing face, a bottom edge and side edges, the frame being mounted in an external wall of a building and being pivotally moveable relative to the frame between an open position and a closed position, the leaf being mounted with its trailing face facing externally of the building and the leading face facing internally, the leaf assembly further comprising a locking device comprising

• a cam rotatable between an unlocked condition and a locked condition, the cam being rotatable in a first direction towards the locked condition and in a second, opposite direction, away from the locked condition, the plane of rotation of the cam being perpendicular to the plane of the leaf when in the closed position, wherein in the locked condition the cam is engageable with a cam engaging surface on the leaf, engagement of the cam with the cam engaging surface preventing the leaf from moving away from the closed position,
• wherein the cam comprises a head portion and a lever portion arranged one on each side of a pivot axis, the head portion including a cam surface having an arcuate profile, the arcuate cam surface being arranged such that it is engageable with the cam engaging surface when the cam is in the locked condition, the assembly further comprising actuating means for rotating said cam from the unlocked to the locked condition, the actuating means exerting a force in use on the lever portion in order to move the cam from the unlocked to the locked condition,
• wherein the frame has at least a first face, the cam being mounted within a corresponding carrier recess in the first face of the frame, the assembly being adapted such that when the cam is in the unlocked condition, the cam is housed fully within the carrier recess,
• wherein the assembly further includes a first cam sealing member incorporated on the cam surface or the cam engaging surface such that a seal forms between the cam and the leaf when the cam is in the locked condition,
• and wherein the cam is arranged to rotate such that when the cam is in the locked condition, exertion of a leaf opening force on the trailing face of the leaf urges the cam to rotate in the first direction, whereby the seal formed between the cam and the leaf is enhanced,
• wherein the lever portion of the cam has a planar surface, the planar surface of the lever portion being arranged such that when the cam is in the unlocked condition and the cam is fully housed within the carrier recess, the planar surface of the lever portion is flush with the first face of the frame;
• the planar surface of the lever portion and the arcuate cam surface of the head portion together forming a continuous surface that extends across the pivot axis.