| 摘要 |
<p>Instrument for testing the effectiveness of foam plastic on the inside of a crash helmet, involves measuring the resistance of the foam to compression, which must lie within fairly narrow limits. Test instrument consists of a tongs shaped element with two amrs (1, 2) with a pivoting point (3). Each arm has a hand grip section (4, 5). The arms are linked by a pressure spring (6). A pressure element (7) is attached to one of the arms. The other arm has the support plate. The pressure element is in the form of a bush with its head operating against the action of a spring. The spring is connected to an indicator instrument which gives a reading of the displacement of the head.</p> |
