Term applied to front-end side vent ducts in conventional ventilation system.
Barrel type fuel tanks that hang from the sides of the tractor's frame.
Society of Automotive Engineers.
Portion on rear quarter panel that extends above the belt line and forms part of the boundary of the backlight and the side window or door openings.
Semi-Axis Manipulator, computerized numerical control machine used primarily to automate welding operations.
SAME DIRECTION COLLISION
A collision between two traffic units moving in the same direction on the same roadway. Sometimes called a rear-end collision.
Devices operated by air for applying sand to the rail in front of or behind the driving wheels of the train.
Composite panel usually formed by high-density skins and low-density core or filler.
A quantity which has associated with it only a magnitude.
Structure erected to house weight recording mechanism used in weighing freight cars.
SCALE TEST CAR
A compact car equipped with weights for the testing of track scales.
A storage track for cars needing to be weighed.
A drawing created by computerized equipment during a scan of a three-dimensional clay modeled surface.
Any sign that the road, roadside, or fixed object has been damaged or marred by a traffic accident.
Discharge of exhaust by means of air pressure.
The location of a traffic accident while people and vehicles involved are still there.
That part of a time table which prescribes class, direction, number, and movement for a regular train.
A device to catch air; may be either functional or merely ornamental.
Surface scratches on panels caused by cold welding between a flange die steel and the sheet metal part. Also known as galling.
A broad area of a hard surface covered with many scratches or striations made by a sliding metal part without great pressure.
A clay-molding tool used to rough in the surface of a model and shaped like a short-handled rake with the straight or curved blade crosswise to the handle. The blade can vary from one inch to six inches wide. It has two sharpened sides, one of which has serrations or teeth and the other a smooth edge.
A light and unusually irregular scar made on a hard surface, such as paving, by a sliding metal part without great pressure.
A tire friction mark made by a tire that is both rotating and slipping on a road or other surface.
Cover over door sill, usually rubber or metal.
1) A security device to assure that truck doors have not been opened in transit. 2) Metal strips, designed for one time use, applied to the hasp of closed freight car / trailer doors. To remove, they must be broken. They are used to indicate whether or not the contents have been tampered with while in transit. They must be stamped with a name, initial and / or number for identification.
Distance from seal mount surface to seal plane.
SEAT SENSOR SWITCH
A switch at each front seating position which senses the condition of the seat (occupied or unoccupied).
A metal or plastic molding or applique on the outer edge of the seat cushion and, in some cases, the seat back.
A mock-up of the interior of a car used to evaluate entrance and egress, seating room, comfort, instrument accessibility, etc. dimensions are usually accurate to plus or minus .03 inch.
A simulated body shell (normally of wood construction) equipped with seats, steering wheel, instrument panel and related interior vehicle components as required to provide a three-dimensional and visual evaluation of ingress and egress conditions, interior passenger room, comfort, accessibility of controls, etc. This property is used to establish and prove-out Engineering and Styling proposals affecting package arrangements prior to the availability of running prototype vehicles.
Secondary shoes in a drum brake system are the shoes which are mounted on the brake plate in a rearward position Each wheel has a primary (front) shoe and a secondary (rear) shoe Sometimes the primary is top mounted and the secondary is on the bottom, but this is not a common type of configuration.
A designated track upon which trains or engines may be operated without timetable authority, train orders or block signals.
View of any component at 90 degrees to a plane cut through the component.
Distance between the rim base and surface of the tread. The unloaded section height at the "top" of the tire will be greater than the loaded section height being compressed against the pavement.
Measure of beam strength in frame rails; must equal the bending moment imposed.
Section width is the linear distance between the exteriors of the side walls of an inflated tire, excluding elevations due to labeling, decoration, or protective bands .
(1) To guard or protect, such as to secure the scene of an accident (2) to make firm or tight, such as the cargo tie-downs or to secure the truck after parking (3) to obtain, such as to obtain help (4) safe and free from danger, such as secure place to stop.
Two-door or four-door car having stationary window frames in its doors.
SELF ALIGNING COUPLER
A coupler which has a taper shank rather that a straight shank to prevent the jackknifing of cars.
Vibrations are termed self-excited if the vibratory motion produces cyclic forces which sustain the vibration.
Any vehicle with or without motive power, other than a pole trailer, designed for carrying persons or property and for being drawn by a motor vehicle, and so constructed that some part of its weight and that of its load rests upon or is carried by another vehicle.
1) The rights of passenger trains over freight and of express over locals. 2) The right of way in one direction on a single track line.
SEPARATION, POINT OF
The point in the collision sequence where collision forces have been dissipated and the objects in contact have the opportunity to physically separate from each other
Factors which must follow one another to contribute to the cause of an accident; generally, operational factors.
a feature of the ignition interlock system which prohibits starting on the initial start if the belt is fastened at any seating position before the seat is occupied.
A circuit in which all controls and current consuming devices are connected in a single line, so that current must pass through each device in sequence. (See parallel circuit.)
A circuit that is made up of combination of series and parallel circuits.
Injury severity of AIS 3 or greater, including for example, compound fractures and internal organ injuries. Unless otherwise noted, summary statistics in this report include all fatally injured persons as seriously injured, but exclude those with unknown severity levels. ( see AIS )
(air brakes) 1) A reduction of air pressure in the brake pipe at a rate that will produce an application of the locomotive and train brakes and a gradual speed reduction. 2) An application of air pressure in the brake pipe at a rate that will produce braking at all service brakes and a gradual reduction of speed.
The service brakes on a vehicle are the brakes (or more accurately, the braking system) used to stop the vehicle in normal use. Service brakes are usually air or hydraulically operated.
SET - UP
A term denoting that an article is put together in its complete state. Not knocked down.
(SI) A measurement of the accelerative forces at the center of gravity of the anthropomorphic test device during vehicle impact.
Pivoting link between spring eye and frame bracket.
The intermediate frequency (5-25 Hz) vibrations of the sprung mass as a flexible body.
SHALLOW ENTRY ANGLE COLLISION
Any collision between two objects in motion in which the angle between their respective directions of travel is less than 15 degrees.
Small building erected along right of way to provide shelter.
All areas of a car not glass, bumpers, grille, lights, or trim, that comprise the body; I.e., hood, fenders, quarter panels, instrument panel, decklid, etc.
Y-shaped components located between the gears on the mainshaft which, when actuated, cause the gears to engage or disengage via sliding clutches. Shift forks are located between low and reverse, first and second, and third and fourth gears.
Consisting of a gearshift lever, pivot pin, spring and boot and housing, it is the main interface between the driver and the transmission.
Extremely then metal pieces used as dividers in the making of a mold.
A self-excited oscillation of a pair of steerable wheels about their steering axes, accompanied by appreciable tramp.
Person or firm for whom shipment originates. Also called consignor.
SHIPPER'S LOAD AND COUNT
Indicates that the contents of a truck were loaded and counted by the shipper and not checked or verified by the transportation line.
A frequent condition of accident victim in which there is a lack of sufficient blood circulation.
A generic term which is commonly applied to hydraulic mechanisms for producing damping of suspension systems.
Structural pedestal constructed to support shock absorber loads and provide for required plunger travel.
Term applied to a structure where building and repairing of equipment is performed, e.g., cars, trailers, tractors or locomotives.
SHORT SILL COWL
Assembly sold to custom body builders consisting of a portion of the floor pan assembly and rockers and the front end assembly.
2,000 pounds. Also called a net ton.
That portion of the road contiguous with the roadway for accommodation of stopped vehicles, for emergency use, and for lateral support of the roadway structure; The line between the roadway and the shoulder may be a painted edge line, a change in surface color or material.
A car having features or shapes not offered in production cars, and designed for display.
Housing located around engine fan for the purpose of utilizing full drawing power of fan.
1) (manual type) Located on top of the fuel pump used to shut off fuel supply to the engine. When the plunger is pushed in, the fuel passage to the injectors is opened. When it is pulled out, the fuel passage is closed. It is important to keep the valve pulled out in the "Off" position whenever the engine is not running. 2) (electric solenoid) Permits the fuel to be shut off or turned on through the use of a switch key similar to that used in automobiles.
The component of the vector acceleration of a point in the vehicle in the y-direction.
SIDE FORCE COEFFICIENT
(C y) is based on the aerodynamic force acting on the vehicle in the y-direction.
SIDE FRAME FIXTURE
Fixture used to locate and hold major panels and assemblies together for welding and line operations.
SIDE GUARD BEAM
Beam inside of doors extending from hinge pillar to lock pillar for added side impact protection.
A skid mark is a tire mark left by a locked, braked, or rotating wheel sliding sideways to its original direction of travel
SIDE SLIP ANGLE
The angle between the heading direction and the velocity direction of the vehicle. This is because when the pre-collision skidding occurs, the heading direction of the skidding vehicle is generally not aligned with its velocity direction at the point of impact.
A track adjacent to the main track for purposes other than for meeting and passing trains.
side velocity (v) of a point in the vehicle is the component of the vector velocity in the y-direction.
(of a tire) The side wall is that portion of a tire between the tread and the bead
SIDE WALL SEPARATION
Side wall separation is the parting of the rubber compound from the cord material in the sidewall of the tire
(Attitude Angle) is the angle between the traces on the X-Y plane of the vehicle x-axis and the vehicle velocity vector at some specified point in the vehicle.
SIDESLIP ANGLE GRADIENT
The rate of change of sideslip angle with respect to change in steady-state lateral acceleration on a level road at a given trim and test conditions.
That portion of the street between the curb lines, or the lateral lines of a roadway, and the adjacent property lines, intended for use by pedestrians.
A track adjacent to a main or a secondary track for meeting or passing trains.
The angle of a line tangent to the lowest exposed surface of the body and the edge of the rocker or quarter pinch-weld flange.
A glass window for determining fluid levels, as in a radiator.
The side of the tractor visible by the driver on the driver's side. Opposite of blind side.
Information stenciled on side of car pertaining to empty car movement instructions.
The main longitudinal members of a car under frame.
Finishing panel on top of rocker in door opening areas.
SIMPLE HARMONIC VIBRATION
Vibration at a point in a system is simple harmonic when the displacement with respect to time is described by a simple sine function.
A pre planned reaction to an expected hazard or other stimulus. Time 0.75 sec, + or -.
Factors which must be present at the same time to contribute to the cause of an accident; generally condition factors.
SINGLE AXLE (SLANG):
Slang for either a tractor with one front axle and one rear axle or a semi-trailer with only one axle.
SINGLE DROP FRAME:
A drop frame trailer with one drop, immediately behind kingpin. See drop frame.
A main track upon which trains are operated in both directions.
SINGLE TRACK VEHICLE
A term used to describe a vehicle whose front wheel tracks in front of the rear wheel. Lines left on the road to mark the path of the tires would appear as a single track.
SINGLE-REDUCTION REAR AXLE:
A rear end that reduces the drive line rpm in relation to the rear wheel rpm by means of a single combination of gears.
Sipes are the slits and slots often found on the circumferential ribs of a tire.
A decorative metal bar mounted on the rear fender at the back of the seat.
The location of a traffic accident after vehicles and people involved have gone.
A circumstance that more or less endangers a traffic unit on a trip and which must be avoided to prevent an accident.
Reference to three-axle truck
A metal skid placed on rail in hump yard to stop cars from running out the lower end of the classified yard.
A bridge which crosses a passageway at other than a right angle.
A visible surface defect caused by movement of the blank over a sharp feature line during the drawing operation.
A skid mark is a mark left on the road surface, or on any surface, by a wheel in a skid The term "skit mark" includes all evidence of skidding such as scuffing of a concrete coat surface, even if no rubber is left behind
Skid number is the frictional resistance of a pavement measured in accordance with the American Society for Testing and Materials, Method E-274-65T, at forty miles per hour omitting water delivery This is the official definition contained in Federal Motor Vehicle Safety -Standards The term skid number is defined as the ratio of skid resistance to normal load on a wheel, multiplied by 100 It can also be defined as the coefficient of friction multiplied by I00
Skid resistance is the frictional force which resists the motion of a skidding wheel or tire
Reference to vehicle tires.
A braking skid mark interrupted by frequent intervals; the skid mark made by a bouncing wheel on which brakes keep the wheel from turning. Compare with gap skid.
To slice or cut off in thin layers.
An adjustable device located on the brake chamber push rod that is used to compensate for brake shoe wear.
A supplementary photo-flash placed at a distance from the master flash to increase the illuminated field in the photograph and fired by a photoelectric device actuated by light from the master flash.
See radio controlled engine.
a deceleration signal used as a model to simulate the barrier crash pattern of a particular vehicle.
SLED RUNNER CHASSIS FRAME
Type of chassis frame in semi-integral frame cars that extends from the front end to the front seat area.
A dynamic test in which a test system is mounted on a sled which is either accelerated or decelerated to simulate a vehicle crash condition.
Truck with a sleeping compartment in the cab.
Area in a tractor where a driver can sleep. Sleeper berths must meet standards set by the Federal Motor Carrier Safety Regulations.
A thin piece of plastic with the edges ground free of all nicks and scratches. It is used to: 1. Smooth a clay surface. 2. Smooth aluminum foil onto clay of fiberglass to simulate chrome trim on bumpers, moldings, etc., and to apply Di-Noc.
SLIDE TO STOP-DISTANCE
(dss): The distance required to decelerate in a skid from an initial velocity to a velocity of zero (0).
SLIDE TO STOP-TIME
(tss): The time required to decelerate in a skid from an initial velocity to a velocity of zero (0).
A lower fork component into which slides the fork tube. This component carries the axle and disc brake assembly.
SLIDING FIFTH WHEEL
A fifth wheel assembly capable of being moved forward or backward on the truck tractor to obtain desired load distribution between tractor and trailer axles.
An adjusted bogies beneath the trailer that can be moved forward or backward to distribute the weight between tractor and trailer axles.
Slip is defined as the ratio of the difference between the angular wheel velocity of a tire which is both rolling and sliding and the angular wheel velocity when the tire is only rolling. Slip is usually expressed as a percentage found by multiplying the ratio by 100
The additional amount of steering angle that is applied to the front wheels of a vehicle in order to generate additional friction force to assist the vehicle in negotiating a turn
Adjustable driveshaft component.
Slip ratio is a parameter which expresses the amount of slippage between the tire and the road, defined by the equation: Vs = Va - Vp Va Where: Vs = Slip Ratio; Vp = Peripheral speed (the speed the vehicle would go if the tire where rolling without slipping. Va = Actual speed of the vehicle.
Engine torque required to slip wheels.
The ratio of a vertical distance change to the horizontal distance change (See Grade ).
A signal identification to proceed at slow speed. See board.
Not exceeding 15 miles per hour.
Surface Layout Release
(Slugged) A visible surface defect in a stampling (usually an out ding) caused by the imbedding of foreign particles in the punch surface of a draw or flange die.
Special Notification Anticipating Receipt of Direction
The extension of pipe for the air intake side of the air cleaner. It enables clean air to be taken in from on the top of the cab.
A snub is a braking deceleration of a vehicle from a higher reference speed to a lower reference speed that is greater than zero It is a slowing of the vehicle by braking, but not a stop.
A generic term which is commonly applied to mechanisms which employ dry friction to produce damping of suspension systems.
Conventional style tractor with the engine protruding into the cab in order to shorten overall length of the tractor.
An area on the shoulder or roadside saturated with liquid debris either at the end of run off or as a puddle marking the rest position of a vehicle after a collision.
The soft or yielding portions of an interior; I.e., seats, door panels, carpets, head-lining, arm rest, padding, etc.
An electromagnetic device that can be used to open and close a circuit (like opening or closing a valve, or engaging the gear of a motor).
Injection of solid fuel in diesel engines.
Solid State Floppy
Portable miniature computer disk with extraordinary Disk Card storage capacity (memory). See SSFDC. ( Detroit )
Reference to single vehicle only.
The kinematics of the impacted pedestrian where the pedestrian is struck by the front of a vehicle and then tumbles to the ground ahead of the vehicle.
Layout drawings or sketches from body engineering at beginning of model year. (XPs)
The collection of marks on a road made by liquid from a vehicle or its cargo squirted from containers on the vehicle by force of collision. Spatter areas are irregular n shape and often consist of many spots.
(Statistical Process Control) is the use of statistical techniques such as control charges to analyze a process or its output so as to take appropriate actions to achieve and maintain a state of statistical control and to improve the capability of the process. Prevention oriented.
Weight of given volume of substance compared to that of an equal volume of water.
(s): A scalar quantity equal to a distance traversed divided by the time required. s = d/t
The vector change in velocity of an object involved in collision.
Instrument to indicate velocity.
The Speeding A condition is met when the vehicle is traveling between the Speeding A and the Speeding B values (default thresholds are 66 mph and 71 mph). ( Detroit )
The Speeding B condition is met when the vehicle is traveling above Speeding B (default threshold of 71 mph). ( Detroit )
MPH-A Speeding Time> MPH-A divided by Driving Time
MPH-B Speeding Time> MPH-B divided by Driving Time ( Detroit )
Spider-like casting or forging containing axle differential or brake parts.
Usually refers to that portion of the floor pan assembly consisting of rocker inner panels, crossbars and reinforcements minus the floor pan.
A very sharp acceleration pulse on a graph of test results.
The axis of rotation of the wheel.
The angular velocity of the wheel on which the tire is mounted, about its spin axis.
What happens when the maximum drive slip resistance has been exceeded by its tractive effort and a sudden increase in driven wheel speed occurs.
See Traction-Limited Grade.
See joint bar.
Series of parallel keys cut along the driveshaft that mate with corresponding slots in hub or fitting.
Total reduction in next lower step of transmission.
SPLIT SERVICE BRAKE SYSTEM
A split service brake system is a hydraulic brake system in which e master cylinder having two pistons supplies pressure to the front and rear brakes through two independent hydraulic systems Thus, loss of pressure on the front brakes does not cause loss of pressure on the rear brakes, and vice versa
Mechanism that divides a gear into two or more ratios such as direct, overdrive, or under drive.
(Statistical Process Management) is a term used to describe a six phase approach using statistical and related methodology to understand and control the variability of product quality.
A spoiler is an upturned ramp or wing-like device mounted at the rear of a vehicle for the purpose of increasing rear wheel traction, or decreasing drag, or both.
A casting with 3,5, or 6 spokes that attaches to the axle and provides a means of attaching a demountable rim to a vehicle. Also called "Cast Spoke Wheel".
To place a car in a designated position or specific location, usually for loading or unloading, such as at a warehouse door.
SPOT FOR AIR
To position the cars in the yard so as to utilize a central compressed air supply to charge the brake system.
A system in which cars and locomotives under going repairs are classified and then moved progressively from one spot to another. At each spot different items of work are done by a unit force.
The fitting of one part of a die to another by applying oil pigment to the surface of the finished part and bringing into contact with the intended mating part, the high spots being marked by the transfer of pigment through contact. High spots are removed until surface is finished to desired smoothness.
The placing of a car where required to be accessible for loading or unloading.
The application of resin and roving with a spray gun.
A two axle assembly in which the axles are separated by distances substantially greater than that in conventional assemblies.
Flexible or elastic member supporting sprung weight of vehicle with recovering properties of returning to original shape when released after being distorted.
Angular amount a metal returns toward its former position after being bent a specified amount.
A device that consists of a conventional brake chamber and an emergency or parking brake mechanism for use on vehicles equipped with fir brakes. The service brake chamber portion of the spring brake is identical to, and functions the same as a brake chamber. The rear portion of the spring brake, sometimes called the "piggyback," houses a large and powerful spring and diaphragm, which under normal conditions, is held in the released position (spring compressed) by air pressure. If air is exhausted from the spring cavity, the spring expands, forcing the diaphragm, push plate, and rod forward, applying the vehicle brakes. A mechanical release bolt at the rear of the chamber is provided to mechanically cage the spring and release the brakes, if necessary.
SPRING BRAKE CONTROL
Controls spring-loaded parking brakes.
The vertical line along which a vertical load applied to the sprung mass will produce only uniform vertical displacement.
U-bolts anchoring spring to axle.
The change of load of a spring per unit deflection, taken as a mean between loading and unloading at a specified load.
Seat or support on which spring is anchored.
A switch equipped with a spring mechanism arranged to restore the switch points to normal position after having been trailed through.
Considered to be a rigid body having equal mass, the same center of gravity, and the same moments of inertia about identical axes as the total sprung weight.
The sprung weight of a vehicle is the weight (or mass) of the vehicle which is supported by the springs It normally consists of the body, frame, engine and accessories (See Unsprung Weight ).
A tool about 2 to 21 feet long with a flat steel chisel edge, used for heavy digging or clay removal.
A gear having the teeth positioned straight across the face of gear.
A stub track extending out from a main or other track.
(Supplier Quality Assurance/Assistance) Ford prefers Supplier Quality Assistance. OEM activity primarily responsible for contacts with outside suppliers on quality.
(Statistical Quality Control) is the measurement of finished rather than in-process product using statistical methods. This method of analysis is normally used on historic data to establish a base-line.. Detection oriented.
(Supplier Quality Engineering) OEM activity that combines the SQA, supplier feasibility analysis and tooling liaison functions. (Ford derived)
(Supplier Quality Improvement) design dates an activity that works intensively on quality improvement with selected outside suppliers during eh prototype and launch phases of new products. (Ford derived)
SQUARE PORTABLE GRID
A sturdy material rectangle which can be placed on the road or other flat surface and included in the foreground of certain photographs.
An electric igniter.
(Supplier Request For Engineering Approval) Ford form number 1638 that producers use to obtain approval of design and process change.
Scientific Research Lab
(Supplier Request for Product Change) a method used by the supplier to document requests for engineering changes for minor dimensional or standard variations from specifications. (Chrysler derived)
Solid State Floppy Disk Card (ProDriver Data Card) Stop Idle Stop Idle is collected when idle time has surpassed a certain preset value (default time is five minutes). It is often a measure of unnecessary idling. Stop Idle Percent Trip Stop Idle Time divided by Trip Time. ( Detroit )
The term is descriptive of the relative stability of a vehicle. The higher the number, the better the stability. The lower the number, the lower the stability.
STABILIZED ACCIDENT SITUATION
The condition prevailing after motion and other action constituting the events of an accident has ceased and no further harm will ensue unless a new series of events is initiated by some means.
Device used to stabilize vehicle during turns. Also called a sway bar.
Truck or trailer platform body with readily removable stakes which may be joined by chains, slats, or panels.
A distance of 4' 8.5" between the heads of the rails. See board gage, narrow gage and gage of track.
STANDARD LOADS AND INFLATIONS
Those combinations of loads and inflations up to the maximum load and inflation recommended by the Tire and Rim Association and published in the yearly editions of the Tire and Rim Association Year Book.
Tire with aspect ratio above 80 (75 for tiers using North American standard designations), and usually in the 90s.
An electric or air powered motor used to set the crankshaft in motion in order to start the engine.
Static amplitude in forced vibration at a point in a system is that displacement of the point from its specified equilibrium position which would be produced by a static force equal to the maximum value of exciting force.
The deformation as measured on a vehicle after the event has occurred. A Reconstructionist would measure this damage on a subject vehicle in a salvage yard.
An electrical charge produced by the gathering of free electrons in one place. The electrons remain at rest until they find a conductor that provides a path to an opposing charge.
STATIC LOAD RADIUS
The loaded radius of a stationary tire inflated to normal recommended pressure. NOTE: In general, static loaded radius is different from the radius of slowly rolling tire. Static radius of a tire rolled into position may be different from that of the tire loaded without being rolled.
The horizontal distance from the center of gravity to the neutral steer line divided by the wheelbase. It is positive if the center of gravity is forward of the neutral steer line.
Static rate of an elastic member is the rate measured between successive stationary positions at which the member has settled to substantially equilibrium condition.
(in (mm)) Static toe-in or toe-out of a pair of wheels, at a specified wheel load or relative position of the wheel center with respect to the sprung mass, is the difference in the transverse distances between the wheel planes taken at the extreme rear and front points of the tire treads. When the distance at the rear is greater, the wheels are "toed-in" by this amount; and where smaller, the wheels are "toed-out".
STATIC TOE ANGLE
(deg) The static toe angle of a wheel, at a specified wheel load or relative position of the wheel center with respect to the sprung mass, is the angle between a longitudinal axis of the vehicle and the line of intersection of the wheel plane and the road surface. The wheel is "toed-in" if the forward portion of the wheel is turned toward a central longitudinal axis of the vehicle, and "toed-out" if turned away.
A reference line along which measurements are made, from predetermined reference points ( in a given direction) and from which measurements are made at right angles ( in a given direction).
Steady-state exists when periodic (or constant) vehicle responses to periodic (or constant) control and/or disturbance inputs do not change over an arbitrarily long time. The motion responses in steady-state are referred to as steady-state responses. This definition does not require the vehicle to be operating in a straight line or on a level road surface. It can also be in a turn of constant radius or on a cambered road surface.
STEADY-STATE RESPONSE GAIN
The ratio of change in the steady-state response of any motion variable with respect to change in input at a given trim.
Steady-state vibration exists in a system if the displacement at each point recurs for equal increments of time.
The angle of motion of the fork assembly about the steering axis measured from a longitudinal axis of the frame point to the direction that the front wheel is pointed while turning.
A steering arm is a lever, attached to the front wheel Of a vehicle, which rotates the wheel about a vertical axis for the purpose of controlling the direction of the vehicle The steering arm is actuated by a linkage element of the steering system
An axle through which directional control of the vehicle is applied. A steering axle may be powered or non-powered. A tractor may have more than one steering axle.
The steering column is the structural housing that surrounds a steering shaft
STEERING CONTROL SYSTEM
A steering control system is defined (FMVSS No 203) as the basic steering mechanism and its associated trim hardware, including any portion of a steering column assembly that provides energy absorption upon impact
A damping device which produces a torque about the steer axis to reduce wobble.
STEERING GEAR RATIO
The steering gear ratio is the ratio of the sector shaft output torque (that is the output of the Sears) to the steering wheel input torque.
The steering knuckles are arms, connected rigidly at one end to the front wheel spindle and connected at the other end to the tie rods The steering knuckles are the end of the steering linkage "chain," the steering -linkage comprising the drag link, the tie rods, the idler arm, and the steering knuckles
The steering linkage is defined as the assemblage of connected parts and pivot joints between the steering Sear and the arm attached to each of the front wheels
The vehicle motion resulting from an input to the steering (control) element.
(control gain) The change in steady-state lateral acceleration on a level road with respect to change in steering wheel angle at a given trim and test conditions.
A steering shaft is the component of a steering system that transmits steering torque from the steering wheel to the steering
STEERING WHEEL ANGLE
Angular displacement of the steering wheel measured from the straight-ahead position (position corresponding to zero average steer angle of a pair of steered wheels.)
STEERING WHEEL ANGLE GRADIENT
The rate of change in the steering wheel angle with respect to change in steady-state lateral acceleration on a level road at a given trim and test conditions.
STEERING WHEEL TORQUE
The torque applied to the steering wheel about its axis of rotation.
STEERING WHEEL TORQUE GRADIENT
The rate of change in the steering wheel torque with respect to change in steady-state lateral acceleration on a level road at a given trim and test conditions.
STEERING, CENTER POINT
Front axle having kingpin perpendicular to the ground line and intersecting centerline of it.
The maximum height of the rocker, including trim and moldings, in the door openings to ground.
V-shaped configuration of rear frame rails to accept tow bar or trailer coupling.
Stipples are small mounds of projections of oil and tar which are left by a rolling tire after it has passed through an oil spot on the road.
A car for transportation of live stock, equipped with slatted sides, single or double deck, and sometimes with feed and water troughs.
STOP (ENGINE) AND EMERGENCY STOP
Some tractors are equipped with a starter button and an "engine stop" switch. The engine stop is used to shut off the engine. Some tractors are equipped with an "emergency engine stop" switch to be used only when the engine starts to "run away" (exceeding the safe upper RPM limits). Once the ever agency stop has been used, the engine will not start again until a mechanic has mite repairs.
Stopping distance is the sum of the reaction distance plus the distance the vehicle travels while the brakes are applied.
A track on which cars are placed when not in service.
STORED GAS INFLATOR
An ACRS inflator which contains high pressure gas (i.e. argon).
Front-end ventilation system with air entering the passenger compartment through vertical ducts in bottom of plenum chamber.
STRAIGHT ACTING GUN
Describes a type of weld gun.
STRAIGHT FREE-ROLLING TIRE
A free-rolling tire moving in a straight line at zero inclination angle and zero slip angle.
A truck with the body and engine mounted on the same chests. (As contrasted to a combination unit such as tractor-trailer).
To effect a change in size or form by application of external force.
Adjusting speed, position on the road, and direction of motion, giving signals of intent to turn or slow, or any action in situations involving potential hazards; any maneuvers while on a trip which increases the chance of success in avoiding an actual hazard.
The forces exerted on, within, or by a body during either tension or compression.
A process involving heat treatment for the purpose of reducing internal residual stresses in a metal.
Narrow, light, parallel stripes or streaks usually made by friction or abrasion on the roadway or vehicle parts.
(slang) Two more freight cars coupled together, as a string of cars.
The distance traveled by the piston from top dead center to bottom dead center of crankshaft.
Rear-door hinge pillar concealed behind and below beltline on four-door hardtops; a pillar that extends only from the rocker panel to the beltline.
A track connected at one end only.
STUD MOUNT WHEELS
Wheels that are designed to center on the studs of a hub. These wheels have chamfers at the bolt holes into which a ball seat or conical nut is installed to center the wheel. The center bore of the wheel is only for clearance of the axle end.
Type of weld gun to weld studs automatically to outer panel to retain moldings and glass.
Movement of the occupant forward and under the restraining device during vehicle impact.
A depressed surface leading to an air scoop.
The degree to which the outside edge of a roadway is higher than the inside edge at a specified point on a curve; the change in elevation per unit distance across the roadway from inside to outside edge; bank.
A type of blower, connected to the engine crank-shaft, that forces air into the intake manifold at higher than atmospheric pressure to increase engine power and performance. See blower.
A train having precedence over another train.
SUPPLY LINES (FUEL)
The lines that carry a supply of fuel to each injector. Fuel enters the inlet connection and then the injectors.
A flat cast-iron plate with five-inch grid lines, inscribed; used as a base to take all dimensions.
An extra panel adjoining a main panel, as in the sheet metal under the grille and between the front fenders.
Attaching parts including springs for securing axle or axles to chassis frame.
(wheel rate) The change of wheel load, at the center of tire contact, per unit vertical displacement of the sprung mass relative to the wheel at a specified load. If the wheel camber varies, the displacement should be measured relative to the lowest point on the rim centerline.
The rotation of the vehicle sprung mass about the x-axis with respect to a transverse axis joining a pair of wheel centers.
SUSPENSION ROLL ANGLE
The angular displacement produced by suspension roll.
SUSPENSION ROLL GRADIENT
The rate of change in the suspension roll angle with respect to change in steady-state lateral acceleration on a level road at a given trim and test conditions.
SUSPENSION ROLL STIFFNESS
The rate of change in the restoring couple exerted by the suspension of a pair of wheels on the sprung mass of the vehicle with respect to change in suspension roll angle.
The term suspension system of a vehicle usually refers to some type of spring arrangement plus a damping arrangement in the form of a shock absorber, along with their support elements. However, the term can also include all of the components which so to make up the Unsprung weight.
A plastic, metal or wood guide used in drawing an irregular or flowing contour.
A slight deviation from a straight ahead path.
1) The degree to which the upper and lower edges of the film in a camera deviate from horizontal when a photograph is made. Swing should be avoided in traffic accident photography because it may misrepresent grades and elevations. 2) Brakeman in the middle of a freight train in charge of setting out cars and braking between the sections of the train handled by head and rear brakemen.
A rear fork with a rear wheel attached, which pivots vertically at the point where it is connected to the frame and whose travel is controlled by one or two springs and shock absorbers.
That instantaneous center in the transverse vertical plane through any pair of wheel centers about which the wheel moves relative to the sprung mass.
The horizontal distance from the swing center to the center of tire contact.
Sides of slaughtered beef, pork, lamb, etc. that are suspended from special racks in a refrigerated trailer.
1) A connection between 2 lines of track to permit cars or trains to pass from one track to the other track. 2) To move cars from one place to another within a definite territory such as an industry, a yard, or a terminal.
Track constructed in a series of zig zag curves in mountainous terrain to reduce rate of climb or decent.
A locomotive used for switching cars in yards and terminals. Sometimes termed switcher. Usually built to carry all its weight on the driving wheels.
A fastener, usually a spring pad lock, used to secure the switch or derail stand in place.
A device by which a switch is thrown, locked, and its position indicated. It consist essentially of a base, spindle, lever and connecting rod, as is usually furnished with a lamp and a banner signal.
A visual day signal fixed on the spindle of a switch stand, or the circular flaring collar fitted around the switch-lamp lens, and painted a distinctive color to indicate the position of the switch.
A synchronizing mechanism to slow down the faster gear, so that engagement of the sifting mechanism can be made quickly and noiselessly without double clutching.
Two or more events or operations occurring at the proper sequence in relation to each other.
Supplier who "packages" separate components to sell to automotive manufacturers, i.e., instrument panel cluster, interior packages.
Caterpillar User's Manual