| 摘要 |
<p>A semi-dump level indicator comprising an electrical system including a pair of mercury switches mounted on the rear portion of the trailer. The switches are closed when the trailer is level. When the trailer is dangerously tilted gravity causes one of the switches to open which de-energizes a relay closing a warning light and alarm buzzer circuit in parallel with the circuit having the mercury switches to warn the operator not to raise the trailer.</p> |
