A

Amperes - a measurement of electrical current flow.

Angle of approach - an angle measured from a horizontal line from the center of the front wheel contact with the ground to the lowest projecting point on the front of the vehicle.

Angle of -departure - an angle measured from a horizontal line from the center of the rear wheel contact with the ground to the lowest projecting point on the rear of the vehicle.

Arc welder - a piece of equipment which unites two pieces of metal through fusion.

Auger base - having a base shaped like a drilling bit that may be screwed into the ground for support.

Axle ratio - the number of teeth in the driven gear divided by the number of teeth in the driving gear.

B

Back-filling - refilling a trench or hole after pipe line or cable has been laid.

Base plate mounting - a heavy metal plate on which certain ' Jeep' equipment such as the compressor, welder and generator are mounted so that the body of the 'Jeep' does not carry the total weight.

Bore - the inside dia.meter of the cylinder.

C

Cam and twin pin - the gear arrangement used in the steering controls on the 'Jeep' vehicles. The steering wheel connects to a cam gear which in turn connects with a twin pin lever. This lever actuates the steering linkage to the front wheels.

Center of gravity - that point through which all the forces pulling downward on a body pass. A vehicle will not tip over until that point passes over the vehicle's contact with the ground surface. Because of the Jeep vehicles low center of gravity they can safely negotiate hilly terrain without danger of upset.

Chamfer - the surface produced by beveling an edge or corner.

Commutator - the part of an electric machine consisting of an assemblage of copper bars each connected to a coil of the winding but insulated from each other.

Compression ratio - the ratio at which the fuel-air mixture in the piston cylinder is compressed before firing.

Constant velocity ball joints - joints in the front axles of 'Jeep' 4WD vehicles which enable the power train to continue to the front wheels even though the wheels are turned.

Cored holes - holes molded into concrete block.

Curb weight - the total weight of an empty vehicle as it sits by the curb. No driver, no cargo, but with a full gas tank, crankcase, and cooling system.

Current range - the spread from the lowest to the highest amount of electrical current available.

D

Deck plate - a metal floor covering with a raised diamond pattern which will withstand a maximum of scuffing and wear and at the same time give protection from slippage.

Discharge gauge - an instrument for measuring the discharge of water in gallons per minute.

Displacement - the cubic area arrived at by multiplying the bore times the stroke times the number of cylinders.

Double jacket hose - fire hose with two layers of cloth jacket woven in opposite directions for extra strength.

Double keyed - two pieces inserted between a shaft and a hub to prevent relative rotation.

Drawbar pull - that amount of force with which a vehicle pulls. This is not to be confused with the amount of weight that the vehicle can tow, which is much greater.

Drill head - that portion of a drill containing the digging bits and attaching to the auger.

Drill stem - that part of a drill to which the revolving augers attach.

Drum - cylinder shaped.

Drum clutch - a device for disengaging the power from the winch drum in order to stop its revolving without completely shutting off the source of power.

Dual friction - refers to the clutch where there are two opposing friction developing surfaces.

Duty cycle - the cycle of operations which a piece of electrical apparatus is called upon to perform whenever it is used.

F

Flotation - the ability of a vehicle to traverse soft terrain without sinking in.

Full floating - refers to front axles of 'Jeep' 4WD vehicles. The axle rotates freely inside the axle housing and absorbs none of the vehicle weight.

G

Gear - any system of moving parts producing motion.

Gear (bevel) - a system of toothed wheels connecting shafts whose axes are at an angle to one another but in the same plane.

Gear (cam) - in the steering system the steering column carries a pair of opposed volute cams which engage with a peg or roller carried by a short arm attached to a drop arm spindle.

Gear (pinion) - the smaller of a pair of high ratio toothed spur wheels.

Gear (spiral) - a toothed gear for connecting two shafts whose axes are at any angle and do not intersect. The teeth are of spiral form.

Gear (worm) - a gear of high reduction ratio connecting shafts whose axes are at right angles but do not intersect.

Gross vehicle weight - the total weight of a loaded vehicle including fuel, oil, water, driver, equipment, and cargo.

H

Heat Exchanger - a device on the 'Jeep' Fire Engine and 'Jeep' Fire Truck whereby the engine is kept from overheating during long periods of pumping.  Water from the radiator passes over coils through which cooler water from the pump is circulated. Consequently the hot water in the radiator is cooled.

High compression cylinder head - a special cylinder head which increases the compression ratio for more efficient performance at altitudes above 5000 feet.

Horsepower - an amount of work done in a definite period of time. Standard definition; the amount of work required to lift 33,000 pounds one foot in one minute.

Horsepower (Brake) - the actual delivered horsepower of an engine as measured on an electric dynamometer. The formula for obtaining brake horsepower is "engine torque in pounds-feet x the number of revolutions per minute divided by 52 52.1 ".

Horsepower (Gross) - the work output of an engine measured on a dynamometer with the generator and water pump operating, but minus the muffler, air cleaner, and cooling fan.

Horsepower (S.A.E.) - the horsepower of an engine as derived from a formula of the Automobile Manufacturers Association to allow a comparison of makes and models on a uniform basis. The formula is "the diameter of the bore squared x the number of the cylinders divided by 2.5 inches.

Hydra-Clutch Pump - the hydraulic pump which is used to power the Lift-0-Matic Tailgate and the Dump-0-Matic Hoist. The pump operates off the fan belt to supply the necessary pressure for equipment operation.

Hydraulic feed - refers to the Mobile Drill. The pressure forcing the augers into the ground is hydraulic.

Hydraulic ram - the moving piston in any hydraulic cylinder.

L

Light stringers - poles for holding electric lights with connecting wires so that they may be extended over a wide area to supply illumination.

M

Moldboard - that part of a plow which cuts and directs the flow of snow or dirt.

O

Overhang - that portion of a vehicle which extends beyond the front or rear axles.

P

Payload - the amount of cargo including the driver that a vehicle can carry. It is the difference between the gross vehicle weight and the curb weight.

Penta bits - a special bit for use with the Jeep-A-Trench for digging through rocky soil.

Percent grade - the horizontal length traveled divided by the vertical length traveled.

Pike pole - a pole with a hook on the end for retrieving objects. Generally used in connection to fire fighting operations.

Pressure regulator - a device on the 'Jeep' Fire Engine and 'Jeep' Fire Truck to regulate the RPM of the engine when hoses are shut down. It automatically cuts down the engine speed to keep pressure from backing up and damaging the equipment. This is especially helpful when two people are manning hoses and one hose is shut down. Without the pressure regulator the additional pressure on the remaining hose would be more than one man could safely handle.

R

Reducer - a fire hose coupling to enable the attaching of a smaller diameter hose to a larger one.

Rheostat indicator - a control for changing the amount of electricity flowing to a given outlet.

Road clearance - the lowest point above the ground of the vehicle. Measured usually at both front and rear axles.

Rotary - having a circular or revolving movement.

S

Section modulus - a method of comparing relative strength of chassis side rails.  Generally speaking the frame with the largest section modulus will have the greatest rigidity and strength.

Semi-elliptical - actually refers to the shape of the springs, i.e. half of an ellipse.

Semi-floating - the rear axle. The wheel bearings are carried directly on the axle shaft; thus the axle shaft and bearings support the vehicle weight.

Sheave - "V" belt pulley

Sheer pin - a piece of metal or wood holding two moving parts of a machine together.  The breaking point of a sheer pin is always less than that of the machine parts so that when some unusual stress or strain is encountered in operation the machine the sheer pin will break rendering the whole unit inoperative. This saves time and money in avoiding costly repairs since as soon as the obstacle is removed and sheer pins replaced the unit can be put back to work.

Shipping weight - the total weight of a vehicle with standard equipment plus grease and oil but minus fuel or water.

Spline - a narrow shaft with longitudinal grooves used to attach to and drive other equipment.

Steel spider - a flat circular gear which has had holes stamped into it to lighten weight.

Stress relieved shafting - a method of hardening the metal used in 'Jeep' construction so that it will withstand successfully the jolts and jars of heavy continuous service .

Stroke - the length of travel of the piston.

Suction gauge - a device on the 'Jeep' Fire Engine and the 'Jeep' Fire Truck for measuring the hydrant pressure and also the vacuum when drafting from an open pond.

Swing gear - the device on the Jeep-A-Trench which connects the speed reducer to the brake drum gear for forward movement.

Swivel runners - small free-swinging pieces of steel on which a snow plow rides.  These runners make the blade follow the contour of the surface being plowed.

Synchromesh - a gear in which the speeds of the driving and the driven gears are first automatically synchronized before engagement thus avoiding shock and noise in gear changing.

T

Tachometer - an instrument which measures the revolutions per minute of the engine.

Tandem Axle - a second rear axle used with the Gran Loader to help support the weight when the fork lift is operating.

Torque - any force of a twisting or rotary action. Here referred to as the twisting force exerted by the engine crankshaft on the drive shaft. Torque is measured in foot-pounds representing the amount of work necessary to raise one pound one foot.

Torque (maximum) - the maximum number of foot- pounds of twisting force generated by the engine. It is usually reached at about one-half full engine speed.

Torque (maximum clutch) - the maximum twisting force that the clutch plate will sustain without slipping. In the case of 'Jeep' vehicles the maximum clutch torque is far above the maximum engine torque to assure no clutch slippage.

Traction - the ability to develop friction on a surface. Four wheel drive means that all four wheels are developing friction in contact with the earth to assure the vehicle getting through the rough spots.

Tread - the distance from the center of one tire on a given axle to the center of the opposite tire on the same axle.

Turning diameter - the diameter of a circle made by the outside front tire of a vehicle as it turns as sharply as possible. The smallest possible area in which the vehicle can turn completely around.

Turning radius - exactly one half of the turning diameter.

V

Volumetric capacity - the total volume of a cylinder.

W

Winch - a steel drum with a quantity of cable which may be actuated so as to spool out or wind in the cable under tension.