ELECTRICAL EQUIPMENT—Q.11Fig. Q.9.Cross Section view of CA 45 Type Starter Motor.The pinion (6) and sleeve (44), mounted on thearmature shaft (5).The sliding plunger (11) mounted on the pinionsleeve.First (13) and second (41) main switch contacts.The moving contacts are mounted on theplunger.The contact trip-trigger (40).The ball-locking collar (17) and trip-collar (19)both mounted on the pinion sleeve.OPERATIONEngagement of the pinion with the engine flywheel ismade in two separate, but continuous stages.First StageWhen the starter switch-button is pressed, thesolenoid (10), is energized. The magnetic field drawsthe sliding plunger (11) forward v, in (8 mm) to meet theshoulder (12), on the pinion sleeve (44).The pinion, now pushed by the plunger, also movesforward, until the pinion nose commences to mesh withthe engine flywheel.Simultaneously, the moving contacts, mounted on theplunger, are also carried forward, causing the first set(13) to close. The second set (41) held by the trip-trigger (40) remain open until the first stage iscompleted. At this point, the plunger slides fully homeagainst the stop (45) on the drive end shield.The first pair of contacts having closed, battery currentflows through the resistance (9) and armature fieldwindings (24). Since the resistance allows a limitedcurrent only, to pass through the field windings. thearmature rotates very slowly. The electrical circuit isshown schematically in Fig. Q.11. This completes thefirst stage of the operation.Second StageThe pinion, already partially engaged and preventedfrom rotating by the engine flywheel will be gentlypushed into full engagement by the helix on the slowlyrevolving armature shaft. However, just before completeengagement is reached, the trip-trigger (40) is lifted bythe forward movement of the trip-collar (19) mounted onthe pinion sleeve. This frees the second set of contacts(41),
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