ISO 4918 Typical castor chair apparatus ——Castor chair test for floor coverings
1. Apparatus
Rotating circular test plaform, on which the test specimens are placed.The diameter of platform shall be a minimum of 750 mm.
2. Castor assembly
This assembly is comprised of a vertical shaft, set in a bearing,and a plate on which the castors are mounted .This castor assembly is offset at a distance of 198mm from the centre of the rotating test platform.
The three castors are each arranged concentrically at 120 intervals around the centre of the plate at a distance of 130mn from the centre of the plate,and are free to rotate, so that follow the rotation of the castor assembly.
The stressed area of the specimen under test is determined by the distance between the axes of revolution of the castor chair assembly and the specimen table,and by the distance of the castors from the centre of the plate. This area is approximately 0.3m*2.
The apparatus is provided with a lifting device to raise the castor assembly above the testing platform when the apparatus is stopped.
The castor assembly is loaded with a mass of 90kg equally divided over the three castors.The distance(under load) between the castor mounting plate and the load/drive plate shall ba >3mm.