Bridging device means that portion of a platform lift that provides a transitional surface between the platform surface and the surface of the vehicle floor within the platform threshold area.
Cycle means deploying a platform lift from a stowed position, lowering the lift to the ground level loading position, raising the lift to the vehicle floor loading position, and stowing the lift. The term includes operation of any wheelchair retention device, bridging device, and inner roll stop.
Deploy means with respect to a platform, its movement from a stowed position to an extended position or, one of the two loading positions. With respect to a wheelchair retention device or inner roll stop, the term means the movement of the device or stop to a fully functional position intended to prevent a passenger from disembarking the platform or being pinched between the platform and vehicle.
Floor reference plane means the plane perpendicular to the longitudinal vehicle reference plane for platform lifts that deploy from the side of the vehicle or perpendicular to the transverse vehicle reference plane for platform lifts that deploy from the rear of the vehicle, and tangent to the outermost edge of the vehicle floor surface adjacent to the lift platform. (See figure 1.)
Gap means a discontinuity in a plane surface, or between two adjacent surfaces.
Inner roll-stop means a device that is located at the edge of the platform that a passenger or mobility aid must traverse when entering and exiting the platform from the vehicle floor loading position and that is designed to retain mobility aids on the platform surface during the range of passenger operation.
Lift reference plane means the plane that is defined by two orthogonal axes passing through the geometric center of the platform surface of a platform lift. One axis is perpendicular to the platform reference plane and the other is parallel to the direction of wheelchair travel during loading of the lift. (See figure 1.)
Loading position means, with respect to a platform lift, a position at which a passenger can either embark or disembark the lift. The two loading positions are at vehicle floor and ground level.
Longitudinal vehicle reference plane means the plane that is perpendicular to the floor reference plane and contains the longitudinal axis of the vehicle when the vehicle body is level and moves along with the vehicle body in response to the loading of the vehicle suspension. (See figure 1.)
Outer barrier is a particular wheelchair retention device that is located on the edge of the platform, is traversed during ground level loading and unloading, and is designed to retain wheelchairs on the platform surface during the range of passenger operation.
Platform means that portion of a platform lift on which the mobility aid or passenger rests while being raised or lowered.
Platform lift means a level change device, including any integration of existing vehicle components, and excluding a ramp, used to assist persons with limited mobility in entering or leaving a vehicle.
Platform reference plane means a plane tangent to the platform surface at its geometric center. (See figure 1.)
Platform surface means the passenger-carrying surface of the lift platform.
Platform threshold area means the rectangular area of the vehicle floor defined by moving a line that lies on the portion of the edge of the vehicle floor directly adjacent to the platform, through a distance of 457 mm (18 inches) across the vehicle floor in a direction perpendicular to the edge. Any portion of a bridging device that lies on this area must be considered part of that area.
Private use lift means a platform lift certified to the requirements for private use lifts and requirements in this standard for all lifts.
Public use lift means a platform lift certified to the requirements for public use lifts and requirements in this standard for all lifts.
Range of passenger operation means the portion of the lift cycle during which the platform is at or between the vehicle floor and ground level loading positions excluding any stow and deploy operations.
Standard test load means a static load or mass centered on the test pallet such that the total combined mass for public-use lifts shall be 272 kg (600 lb), and the total combined mass for private-use lifts shall be the lift manufacturer's stated rated load or 181 kg (400 lb), whichever is greater.
Stow means with respect to a platform, its movement from a position within the range of passenger operation to the position maintained during normal vehicle travel; and, with respect to a wheelchair retention device, bridging device, or inner-roll stop, its movement from a fully functional position to a position maintained during normal vehicle travel.
Test pallet means a platform on which required test loads are placed for handling and moving.
Transverse vehicle reference plane means the plane that is perpendicular to the floor reference plane and contains the transverse axis of the vehicle when the vehicle body is level and that moves along with the vehicle body in response to the loading of the vehicle suspension. (See figure 1.)
Wheelchair retention device means a device designed to prevent wheelchairs from leaving the edge of the platform used for ground level loading and unloading during the range of passenger operation.
Contrast = 100 * [(L1-L2)/L1]
Where:
L1 = luminance of the lighter color or shade, and
L2 = luminance of the darker color or shade.
L1 and L2 are measured perpendicular to the platform surface with illumination provided by a diffuse light and a resulting luminance of the platform surface of 323 lm/m2 (30 lumen/sqft).
49 C.F.R. §571.403