Section II. DEFINITION OF UNUSUAL TERMS

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Section II. DEFINITION OF UNUSUAL TERMS - CONTINUED

Blind Rivet. Hollow rivet with ball-headed nail through its center. This rivet is installed by special

tool which pulls on nail, expanding unflanged end of rivet securing it, and then breaks off nail.

Brinnelling. Type of wear or damage to bearing characterized by many small dents or pits.

Diesel Engine. internal combustion engine in which fuel-air mixture is ignited by heat generated by

compressing air-fuel mixture. Unlike gasoline engine where air-fuel mixture is ignited by electric

spark.

Diode. Electronic device which allows electricity to flow in only one direction.

Fifth Wheel. Round coupling and support device mounted on truck tractor to pull semitrailer.

Optical Ribbon. Ribbon made up of glass fibers which carries light.

Pusher Axle. Truck or trailer axle which can be lowered to help support load and raised when not

needed. Used on some roadways which cannot support full load per wheel.

Performed Packing. Round neoprene or synthetic rubber seal or gasket. Also known as an O-ring.

Quick Release Valve. Valve in airbrake system which allows air pressure used to apply brakes, to be

exhausted near brake chambers rather than having to exhaust it back through treadle valve. Allows

brakes to release more quickly.

Relay. Electrical device that allows small current to control larger current.

Relay Valve. Airbrake valve that allows pilot air, small in both volume and pressure, to control larger

flow in volume or pressure.

RPSTL. Repair Parts and Special Tools List. Army parts catalog.

Semitrailer. Trailer where part of load is carried by towing vehicle.

Spring Brake Chamber. Device in airbrake system where brakes are normally applied by large spring

while parking or during an air system failure. Spring is held back during driving by air system

pressure. Spring brake chambers are installed as safety device in case of an air system failure, and to

hold truck while parked.

TOE. Table of Organizational and Equipment. A listing of number and types of personnel and

equipment required to makeup an army unit.

Transfer Case. Gearbox which drives drive shafts, which drive front and rear axles.

Treadle Valve. Valve in airbrake system which controls brakes by driver's foot pedal.

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