🔍 Key Concepts

• Trace the power flow from the turning gear motor through the worms, worm gears, and shafts in the illustration. • Identify what the engaging handle, yoke, and locking device actually move or lock in place. • Consider how an electrical “turning gear engaged” indicator is usually wired in relation to a mechanical position switch.

💭 Think About

• Follow the rotation: when the turning gear motor runs, which specific gears and shafts MUST turn, and which parts only move when the engaging handle is operated? • Look closely at the locking device in the drawing—does it appear to act on the motor coupling, or on some other moving part of the engaging mechanism? • For the indicating lamp, think: should power reach the bulb only when the gear is engaged, or all the time? From that, what contact state (open or closed) makes sense for the position switch when the gear is NOT engaged?

✅ Before You Answer

• Verify from the sketch whether the 2nd reduction worm gear is permanently meshed and keyed to its shaft, or if its rotation depends on the engaging handle position. • Check what part of the mechanism the locking device is physically attached to in the illustration (coupling vs. yoke/handle). • For the lamp circuit, be sure you know whether the position switch changes from open to closed (or closed to open) when the gear is engaged, and what condition is needed for the lamp to receive power.