| 摘要 |
1,061,307. Jib cranes. C. E. MENNERDAHL. Jan. 22, 1966, No. 3379/66. Heading B8B. The jib of a crane comprises outer and inner portions 5, 4 hinged together about a vertical pivot 7 the inner portion being rotatably mounted on a post 1. The outer portion contains a ram which supports a plurality of pulleys on its piston-rod, a lifting rope 31 passing round these pulleys and further pulleys on the end of the outer portion. One end of the rope is anchored within the outer section. The pivot 7 is offset so that the jib may only be folded in one direction, a rope 36 being provided for this purpose. In a modification lugs are provided for accommodating a pivot pin on both sides of the inner section of the jib and the pivot pin is removable. To reverse the direction of folding of the outer section this section is detached by removing the pivot pin, rotated about its longitudinal axis through 180 degrees and re-connected to the opposite pair of lugs. |
