| 摘要 |
<p>An hydraulically actuated tool has a body (120), an hydraulic fluid supply (81), a head chamber (54) and an actuable member (52) adapted to be actuated by pressure within the head chamber (54). An hydraulic drive arrangement (300) is configured to draw hydraulic fluid from the hydraulic fluid supply (81) and drive the hydraulic fluid under increasing pressure into the head chamber (54). An indicator assembly (700) is mounted in the body (1,20) and has an indicator member (701) displaceable between a retracted position and an extended position protruding from the body (120). A pressure relief valve assembly (500) is adapted to open upon pressure within the head chamber (54) reaching a predetermined threshold pressure. Opening of the pressure relief valve assembly (500) communicates the head chamber (54) with the indicator assembly (700) to drive the indicator member (701) to the extended position and communicates the head chamber (54) with the hydraulic fluid supply (81).</p> |
