| 摘要 |
<p>Improved power and free trolley apparatus includes independent pusher and hold back dogs positively moved to an accumulate position by a counterweighted actuating lever moving to an accumulate position. The dogs, however, are self-biased, the pusher dog self-locking in its drive position, and the dogs are not interlocked with the lever. They move independently of the lever into operative position when the lever is moved into a non-actuating position and out of blocking relationship with the dogs. The actuating lever counterweight defines a trolley brake for preventing excessive trolley bounce back during accumulation. Another aspect of the invention includes a movable cam selectively raising a drive dog in a trailing trolley for switching, and permitting accumulation of trolleys through a switch zone when held in an inoperative position as when the switch zone is choked.</p> |
