| 摘要 |
<p>There is disclosed a crane having a base section, and an upper section separable from the base section. An anti-friction bearing on which the upper section swings relative to the base section has an outer race member connected to the base section. The inner race member of the bearing receives therein a ring on the upper section when the upper section is mounted on the base section. Opposing circumferential grooves in the ring and inner race member receive a locking ring which is expanded and contracted by a power actuator. When the ring bridges the grooves, the upper crane section is locked to the crane base section, and when the ring is contained entirely in one of the grooves, the crane upper section is released from the crane base section for separation of the sections.</p> |
