| 摘要 |
FIELD: transport.SUBSTANCE: claimed crane comprises crane mount (3) to turn about vertical axis (V). Said crane comprises jib (4) with its extension (5) sliding therein to turn about horizontal axis (H). Cylinder/piston assembly (6) serves to extend and to pull in the jig extension (5) relative to jig (4). Said assembly (6) acts by its first end via force application first area (7) on jig (4) and by its second end acts via force application second area (8) on jig extension (5). Said assembly (6) has mid plane (M) extending in the direction of observation parallel with horizontal axis (H) for jig (4) to turn thereabout. Said assembly (6) as-loaded endures at extending a compressive stress (D) on direction perpendicular to said mid plane (M). Or, as-loaded at pulling in it endures expanding stress (Z) in direction opposite that of stress (D). Assembly (6) acts by its second end via two force application areas (8) on jig extension (5). One of said areas (8) is shifted relative to mid plane (M in direction opposite compressive stress (D). Another one of said areas (8) is shifted relative to mid plane (M) in direction opposite expanding stress (Z).EFFECT: perfected design.12 cl, 14 dwg |
