| 摘要 |
<p>A soot blower lance tube indexing mechanism (54) including a pinion (64), first and second pinion ratchet/sprocket assemblies (76, 78), a spindle (32), first and second spindle sprockets (58, 60), and a clutch. The clutch is operable to link the first pinion ratchet/sprocket assembly (76) with the first spindle sprocket (58) to rotatably drive the spindle (32) in a first direction when the lance tube (30) is extended. The clutch is further operable to link the second ratchet/sprocket assembly (78) with the second spindle sprocket (60) to rotatably drive the spindle (32), when the lance tube (30) is retracted. In an alternative embodiment, the lance tube (30) rotates in a single direction regardless of whether the lance tube (30) is being extended or retracted.</p> |
