| 摘要 |
A pivotal joint in which a first member (10) having a wheel-shaped end (18) is pivotally connected to a second member (12) having a forked end (22) enveloping the wheel-shaped end and including a primary pivot bolt (30) arrangement extending through the first and second members at the center of the wheel-shaped end to pivotally join the parts, as the primary pivotal connection therebetween and wherein the forked end of the second member presents a circumferential array of three friction surfaces (24, 26, 28) which will cooperate with the periphery (20) of the wheel-shaped end of the first member to pivotally join the two parts as the secondary pivotal connection therebetween if the primary pivot connection fails. |
