| 摘要 |
1382495 Crane trolleys POTAIN 18 April 1972 [12 May 1971] 17997/72 Heading' B8B A tower or bridge crane distributing trolley comprises two components a "standing trolley 3" and a "single-tackle trolley 2". A lifting cable 7 from a winch (not shown) passes (from the left as shown) over a pulley 20 on standing trolley 3, over a pulley 22 on tackle 5, over a pulley 19 on the standing trolley 3, over a pulley 25 on the tackle trolley 2, over pulleys 26, 27 on a lifting compensation bar 4 with a load hook and finally over a pulley 24 on the tackle trolley 2 and thence to an anchor point 8. As shown in Fig. 3 the standing trolley 3 and the tackle trolley 2 are latched together to move as a unit and the tackle 5 is latched to the compensation bar 4 to move with it and provided four falls of lifting cable 7 at the load. Alternatively the standing trolley 3 can be latched to the left-hand end of the trolley track, as shown in Fig. 2, with the tackle 5 held underneath by the lifting rope (being unlatched from the compensation bar 4) leaving the tackle trolley 2 free to move with only two falls of lifting cable at the load. The latching and unlatching operations are carried out using the lifting cable 7. |
