| 摘要 |
<p>1461970 Crane counterweights J I CASE CO 13 Dec 1974 [22 April 1974] 53935/74 Heading B8B A crane (10), Fig. 1 (not shown), has a counterweight 30 mounted on a telescopic support 20 pivoted on crane base 14 at 26 and maintained horizontal by a pin 50. The counterweight 30 is moved from its retracted position, Fig. 2 (not shown), to its extended, operative position, as shown, by a fluid ram 54. Further, slight, extension of the ram 54 pivots the support 20 upwards to take the weight off the pin 50 which can then be removed whereupon retraction of the ram 54 pivotally lowers the counterweight to the ground as indicated in broken lines.</p> |
