| 摘要 |
<p>BOOM PROP A boom prop for supporting in an elevated position a pair of boom arms interconnected by a cross tube, including a link pivotally mounted on a vehicle with a saddle member secured to its free end capable of engaging and supporting the cross tube. An adjustable stop means positions the saddle member in the path of the cross tube so that the link and saddle are cammed out of the path of the cross tube as the boom arms are raised and gravity returns the saddle to the position determined by the stop means when the boom arms are subsequently lowered.</p> |
