The aluminium or steel threshold plate fitted at the bottom of both the car entrance and each landing entrance, bridging the gap between the stationary landing and the moving car floor and providing a guide groove for the door panels.
Full Definition
The elevator sill (car sill and landing sill) serves dual functions: (1) Structural bridge — spans the gap between the car floor and the landing floor to provide a continuous, level walking surface for passengers boarding and alighting; (2) Door guide groove — the sill incorporates a machined groove (or multiple grooves for multi-panel doors) in which the lower edge of the door panel slides; the groove keeps the door panel stable, prevents it from swinging outward, and constrains its lateral movement. EN 81-20 specifies: maximum gap between car sill and landing sill: ≤35 mm at any floor stop (to prevent objects falling into the pit and to limit entrapment risk); sill groove clearance to door shoe ≤3 mm. Sill materials: extruded aluminium with a mill-finish or anodised surface is most common; stainless steel for high-traffic and high-abuse environments. The sill must align precisely with the car floor to ensure a level transition; levelling systems (e.g. floor-level sensors and VVVF drive levelling control) target ≤±5 mm sill-to-floor flush tolerance. Worn sill grooves cause door shoe damage and door mis-operation — a common maintenance finding.
