(under the class definition) Subject matter wherein (a) a damper is provided to prevent sudden uncontrolled upward or backward movement of the boom* or (b) means are provided to limit upward or backward movement of the boom by direct contact.
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276+, for traversing hoists having means to disable or stop boom rotation in response to an unplanned or unpredictable occurrence, and to control boom rotation in response to a sensed condition.
SEE OR SEARCH CLASS
414, Material or Article Handling,
673, and 719 for similar devices on other load handlers.