Fig. 78. Atwater Kent Automatic Spark Advance Mechanism—A K Type K-2
[Fig. 78] shows the automatic spark advance mechanism. It is located on the underside of the contact maker base plate, and consists of a set of weights which swing out from the center against spring tension, and advances the unisparker on the shaft, according to the amount of centrifugal action or speed of the shaft. When the shaft is not in motion the springs draw the weights toward center, which automatically shifts the unisparker on the shaft until the spark is in a fully retarded position.
Contact Point Adjustment.—The only adjustment aside from the initial timing is in the contact points. They are adjustable only for natural wear, and one adjustment should last at least six months. The contact screw is provided with a number of shim washers against which it is set up tight. When the points eventually become worn, they should be dressed flat and smooth. A sufficient number of the washers should be removed so that when the contact screw is set up tightly it will maintain the proper gap between the points. The distance between the contact points should be about the distance of a thin visiting card. They should never touch when at rest.
Oil lightly every
1000 miles
Oil
Fig. 79. Atwater Kent Contact Breaker—Oiling Diagram—A-K Type K-2
[Fig. 79] shows an oiling diagram of the contact maker. The latch, lifter, and lifter spring are not adjustable or subject to wear. They should be well cleaned and oiled every five hundred miles. Use a light oil and avoid getting it on the contact points.
The Condenser.—The condenser of this system acts somewhat like a shock absorber to the contact points. It absorbs the spark or arc and makes the break in the primary current, clean and abrupt. The condenser is very accessible, but should never be tampered with, as it does not require any attention.