One of the most successful product of the client is the mobile x-ray machines. These machines are transported within the hospital facilities to where they are required, so the patients do not need to be moved. The machines have a weight of more than 500 kg and have an extendible arm to facilitate the x-ray operation. Each machine has two drive wheels and two spring-loaded castors with antistatic wheels.
The original castors’ wheels were from a competitor and the brackets were manufactured by other suppliers. The client received a castor which was manufactured by several companies. These castors had several problems with detachment of the tread due to the malfunctioning of the springs. The springs were not properly designed, and the wheels hit the bracket producing cracks in the tread. But the most important problem was the electrostatic discharge which led to electronic failures of the machine controllers and potential hazard to the operators.
The client needed a complete castor which is easy to mount to the existing machines, using stem fittings. The initial tension of the springs needs to be high enough so that these are not compressed when the arm of the machine is extended, and the springs must be able to buffer the effects of ground irregularities and obstacles.