| 摘要 |
A device for use in connection with sports and athletics exercise for recording overstep in relation to a predetermined reference line, which may be a start line or a take-off line for measuring the length of a jump or throw. The device comprises a step cushion which is located in direct connection to the reference line and extends along the line, and which encloses an airtight cavity of a definite volume provided with air of a predetermined pressure, and which is capable upon being loaded on its upper surface of instantaneously reducing the volume of the cavity for obtaining a pressure increase, and a pressure indicator connected to the cavity which in response to such pressure increase causes a signal member to emit an optical and/or acoustical signal. |
