摘要 |
<p>A winch has four drive trains of progressively increasing mechanical advantage between its drive shaft (3) and drum (8). If a selector (40) is engaged, rotation of the shaft in successively opposite senses will cause automatically engagement of the first third and fourth trains in sequence. If the selector (40) is not engaged and an override control (80,81,82) is appropriately set, the sequence second, third, fourth trains is followed. But the override may be locked so that only second and third trains are engaged alternately.</p> |