Safeguarding of pinch and shear points on power windows by limitation of the closing velocity: A pilot study

Power-operated windows are increasingly employed in modern buildings engineering. When they close, these windows give rise to pinching and shearing points between the window sash and the frame at which injury may occur. A number of safety measures, including reduction of the closing velocity, may be considered for minimization of the risk of injury. The purpose of the present study is to identify the closing velocity at which a person may still withdraw their hand safely from the window. The subjective stress was also measured. The deformability of the fingers was first determined. In order to measure reaction times, test apparatus was fabricated in which a vertically closing window was modelled. The reaction times and the subjective stress were measured at a number of closing velocities.The results show that neither the reaction times, nor the subjective stress vary as a function of the closing velocity, but that the closing velocities recommended in the past are too high. A velocity of between 2.5 and 5.0 mm/s may be recommended. Reduction of the closing velocity can help to reduce the risk of injury. It should not, however, be the sole measure for enhancing the safety of power-operated windows.