Babbitt
An alloy used for the linings of shaft bearings, which possesses excellent antifriction properties and which is not likely to mar the shafts which run upon it. It is readily melted and cast into the form required to fill the space between the shaft to be supported and the caps and stands of the bearing or journal. Babbitt or some similar alloy is generally used for gasoline engine crank and cam shaft bearings, for connecting rod tip bearings, and elsewhere. Its composition is somewhat variable, but the following is a commonly used formula: Tin, 84.00 per cent.; antimony, 9.00 per cent.; copper, 7.00 per cent. Alloys known as nickel babbitt and white bronze are extensively used in place of true babbitt.
Backfiring
The communication of the flame of explosion in a gasoline engine cylinder to the gas in the intake piping and that in the carburetor, resulting in an explosion of the same, the noise of which is known as “popping” in the carburetor. It is usually caused by faulty valve action, by very late ignition, or by the use of a slow burning mixture. In practice it is usually a sign that the mixture furnished the engine is too weak, that is, contains too small a proportion of gasoline vapor. The term is also sometimes applied to the explosion of the mixture in the crank case of a two cycle engine.
Backlash
Looseness between a driving and a driven part, which permits the former to be moved relatively to the latter without producing the intended motion in the latter. It is usually developed through wear of the acting surfaces of the driving and driven parts, or may be due to their incorrect adjustment. Synonym: Lost motion.
Back
Kick The starting of a gasoline engine backward or in the reverse direction of rotation. It is caused by an explosion taking place considerably before the piston affected has completed its upward of compression stroke. If such explosion occurs while the motor is being cranked in the normal direction, the operator is likely to be injured thereby. Too early ignition is the cause of this phenomenon.
Back Pressure
The gaseous pressure which acts to resist the piston movement of a gasoline engine while its cylinder is being cleared of burnt gases, on the exhaust stroke. This results in negative work and a reduction of engine output.
Baffle Plate
A plate placed in a chamber containing fluid to restrain the free movement thereof. Examples: An oil baffle plate is a perforated plate placed across the lower end of a gasoline engine cylinder to limit the amount of lubricating oil which is splashed up from the crank case upon the cylinder walls. Baffle plates are sometimes fixed within the fuel tank to prevent the excessive splashing about of the gasoline, when the car is in motion. (Swash plates.) Such plates are also used in exhaust mufflers to cause the spent gases to follow circuitous paths in their passage to the open air.
Balance
That quality of a moving part or system of moving parts of a mechanism which enables it to move without jar or vibration and without imposing excessive inertia stresses upon its bearings. (See counterbalance.)
Balance Wheel
A heavy rimmed wheel carried upon the crank shaft of a gasoline engine and rotated thereby, for the purpose of steadying the running of the engine. When once set in motion it tends to continue to rotate and furnishes stored energy to keep the engine turning during intervals of the cycle when the power required for propulsion exceeds that developed in the cylinders. The balance wheel may also deliver stored energy and assist in driving the car during short periods when an excessive driving effort is called for, as at starting.
Synonym: Flywheel.
Ball Joint
A form of joint for connecting two members of a linkage so as to permit of a considerable range of angular relation between them. The connecting end of one member is in the form of a ball, and that of the other is in the form of a cup or partial sphere, which encircles and holds the former. Such joints are employed in the steering linkages and in the throttle and spark control linkages of motor cars and a similar construction is sometimes used to .connect the forward end of the drive shaft housing to its support upon the car frame.
Synonym: Ball and socket joint.
Ball Joint, Spring
A form of ball joint employed in the steering linkage at the forward end of the rod, which connects the steering device with one of the steering knuckles. The cup and ball connection is cushioned by springs contained within the tubular rod, which permit the joint to give slightly when sudden shocks are communicated to it from the road wheels. This prevents the communication of these shocks to the hands of the operator.
Synonym: Spring buffer.
Base Explosion
The accidental explosion of the gas contained in the crank case or base of a two cycle engine, by flames extending from the cylinder through the transfer passage. This generally results from too late ignition or from the use of a slow burning mixture.
Synonym: Crank case explosion.
Battery, Commutated
An arrangement of the storage cells of an electric vehicle in which the cells are divided into several equal groups. These groups, by means of a special controller, may be connected to the motor, either in multiple or in series and thus any one of several voltages may be impressed upon the motor at will and several speeds obtained from it without the necessity of much dead resistance being employed.
Battery, Divided
An arrangement of the storage battery of an electric vehicle in which the cells are divided into two groups, carried in the forward and rear parts, respectively.
Battery, Dry
A battery made up by connecting together a number of dry cells (q. v.).
Battery, Interchangeable
An electric vehicle battery so arranged that it is readily removable as a unit from its car when exhausted and which is replaceable by a similar battery that is fully charged.
Battery, Storage
A battery formed by connecting together a number of storage cells or accumulators (q. v.).
Battery, Underslung
A vehicle storage battery, which instead of being carried in the car body, is suspended underneath the vehicle frame.
Battery Box
The box which contains the ignition or lighting battery of a car. It is generally carried upon the running board or under one of the seats and is usually made of pressed steel and lined with insulating material. Some boxes intended to hold dry cells are so arranged that the act of putting the cells in place therein automatically makes the necessary electrical connections. These are called wireless battery boxes.
Battery Gauge
An instrument for roughly testing the condition of dry cells or storage cells. The dry cell gauge is merely a low resistance ammeter, reading up to 30 amperes or so. The dry cell is short circuited through this, the reading indicating approximately the internal resistance of the cell, a high ampere reading indicating a low resistance cell and vice versa.
The storage cell gauge is a low reading voltmeter, calibrated up to 10 v. or so, which indicates the voltage of the cell and thus furnishes some indication of its state of charge.
Synonym: Battery tester, pocket ammeter and voltmeter.
Battery Platform
A platform used in electric vehicle stations to facilitate the handling of interchangeable storage batteries. The platform is of such a height or may be raised to such a height by an elevator that when the vehicle is properly drawn up alongside it the battery may readily be slid into or out of it without heavy manual labor being required.
Battery Tray
A tray in which are assembled the cells which constitute a storage battery or a section of a storage battery, for convenience in handling.
Baume Scale
An arbitrary scale used to indicate the density or specific gravity of liquids. There are two such scales, one used for liquids heavier, and one for liquids lighter than water, the latter being mainly employed to define the density of gasoline. In this scale, the denser the liquid, the lower the Baume degree which it tests, and vice versa. Gasoline, as at present obtainable, tests from 62 to 70 degrees Baume (abbreviation B.). Direct determinations of density according to the B. scale are generally made by the hydrometer (q. v.).
Bearing
In general, the support of a moving part within which it moves in a prescribed manner; more specifically, the support of a shaft within which it is so held as to permit its rotation. (See bearing, plain; bearing, ball; bearing, roller, etc.)
Bearing, Annular Ball
A form of self-contained, inadjustable ball bearing, which consists of two concentric, hardened steel rings or annuli, one larger than the other, the internal periphery of the outer ring, and the external periphery of the inner ring being appropriately grooved to form a race which, when the rings are assembled, one within the other, is filled with a series of steel balls, sometimes separated by spiral springs. Such a bearing is specially intended to support radial loads, its capacity to resist end thrust along the shaft being relatively limited.
Bearing, Ball
A form of anti-friction bearing in which the rotating shaft and the fixed portion of the bearing are not in sliding contact, but are separated by a series of hardened steel balls. A hardened steel fitting fixed to the shaft rolls upon the balls, and the balls in turn roll upon a hardened steel fitting secured to the fixed portion of the hearing. The action is thus nearly a purely rolling one and sliding friction is practically abolished. There is but little loss of energy in such a bearing and it requires relatively little lubrication.
Bearing, Cup and Cone
A form of ball bearing in which a line of balls rolls in a race formed between a hardened steel cone-shaped fitting fixed to the shaft and a cup-shaped fitting fixed in the bearing support. The shaft carried cone rolls upon the balls and the balls roll upon their race in the cup, two, three or four lines of contact being allowed between the balls and their race in different designs. Such bearings are usually made adjustable for wear, by moving the cup and cone closer together. They are well Cup and Cone adapted to resist end thrust on the shaft in either direction, as well as to support the radial load.
Synonym: Bicycle type ball bearing.
Bearing, Hardened Steel
A form of plain bearing in which the shaft rotates in a glass hard steel bushing ground to a true surface. The shaft is made of relatively soft steel. It is claimed that such bearings operate with little friction, are not likely to rough up their shafts, and require only a small amount of oil. They are not much used.
Bearing, Main
A term applied to the bearings in which the crank shaft of a vehicle engine rotates.
Bearing, Plain
The common, primitive form of bearing in which the rotating shaft is in sliding contact with the bearing which supports it, a considerable area of contact between the two being allowed.
Synonym: Parallel bearing.
Bearing, Radial
A bearing adapted to resist a radial load, i. e., a load in a plane at right angles to the axis of the shaft which the bearing supports, such as the weight of parts carried upon a horizontal shaft or the effort transmitted through the connecting rods to the crankshaft of a motor. In radial ball hearings the diameter of contact of the halls is perpendicular to the axis of rotation of the shaft. The term is used in contradistinction to “thrust bearing».
Bearing, Radial Thrust
A hearing capable of resisting both radial load and thrust. In two point contact ball bearings of this type, the diameter of contact of the balls is inclined to the axis of rotation of the shaft, and thus both the inadjustable, annular “two-in-one”‘ bearings, with two rows of balls, and the adjustable cup and cone bearings (q. v.) may be included in this class.
Bearing, Conical Roller
A form of anti-friction bearing in which hardened steel rollers are used to secure rolling contact between shaft and journal. Such a bearing consists of a hardened steel cone carried upon the shaft and a concentric internally coned cup fixed within the bearing support. Such a bearing is adjustable by moving the cup and cone together, and is well adapted to resist both radial pressure and end thrust. Used in axles, steering pivots and wheels, on gear shafts, etc. Synonym: Taper roller bearing.
Bearing, Cylindrical Roller
A form of roller bearing with hardened cylindrical bearing surfaces, separated by and rolling upon hardened cylindrical rollers. Adapted to resist radial loads and usually inadjustable.
Bearing, Thrust
A bearing adapted to resist pressure parallel with the axis of rotation of its shaft.
Bearing, Ball Thrust
A form of ball bearing adapted to resist the pressure upon a shaft in the direction of its length the end thrust. It consists of a hardened steel collar fixed upon the shaft and another corresponding stationary collar fixed in the bearing support. Between these collars is a series of steel balls suitably held in a cage. Used in drive shafts, axles, clutches, etc.
Bearing Bracket
A projection on a structural part or a specially formed portion of such a part, adapted to support a bearing.
Synonym: Bearing stand, bearing support.
Bearing Cap
The portion of a plain journal which is detachable from the fixed stand or bracket thereof and which serves to secure the bearing bushing and shaft in position. It is usually secured to the stand or bracket by cap screws and may be made adjustable by the provision of shims (q. v.).
Bearing Shell
A removable, hollow cylindrical, metal lining, adapted to be held within the bracket and cap of a plain bearing, and to the inside of which is applied the actual bearing surface of babbitt or similar anti-friction metal upon which the shaft rotates.
Synonym: Liner.
Bearing Surface
The area of the projection of a bearing on a plane perpendicular to the direction of the bearing pressure. In the case of cylindrical bearings (shaft bearings), it is equal to the product of the length by the diameter.
Bell Crank
A lever with its two arms angularly disposed and pivoted at their point of intersection, adapted to transform a push or pull applied to one arm in a certain direction into a push or pull delivered by the other arm in a different direction, for instance, at right angles. Used in control linkages.
Benzol
Coal tar benzine (C 8 Hc), a product of the destructive distillation of coal tar. Sometimes used either alone or in combination with gasoline or alcohol as motor fuel, especially in Europe. Also sometimes used as a rubber solvent in making cements.
Bevel Gear Drive
A method of driving a shaft from another shaft arranged at an angle thereto (commonly at a right angle), by means of a pair of mitre or bevel gears.. It is specially employed for transmitting the driving effort of the motor to the traction wheels of motor cars in which the motor shaft is located lengthwise of the car and thus at right angles to the axle. Such a drive consists of a universally jointed longitudinally disposed shaft driven by the motor and carrying a bevel gear or pinion upon its rear end, which meshes with a corresponding bevel gear secured to the differential frame of the live rear axle, so as to drive the axle and its two traction wheels. Overhead cam shafts and some of the auxiliaries are sometimes actuated by bevel gear drives.
Bevel Gear Drive, Double
A form of sliding gear (q. v.) change speed (q. v.) device of the direct drive type, sometimes employed to drive the countershaft (q. v.) of a double chain driven car (see chain drive, double) in which two bevel gears, secured to the differential gear (q. v.) housing are used, one of which is in permanent mesh with a bevel pinion upon the end of the lay shaft (q. v.) and the other in permanent mesh with a bevel pinion upon a short shaft to which the engine driven sliding shaft (q. v.) is clutched when the direct drive is in action. When the direct drive is in use the latter bevel pinion drives the differential and countershaft, the lay shaft and its bevel gears rotating idly, but on all other speeds the lay shaft bevel pinion drives the differential and countershaft and the other bevel pinion and its shaft rotate idly, the direct drive clutch being disengaged.
Binding Post
A part of a piece of electrical apparatus to which attachment of the external circuit is made. Usually some form of clamping device adapted securely to hold a wire in electrical contact. The binding post is the point of connection between the electrical conductors forming a part of the apparatus itself and the conductors forming the external circuit.
Bleeder
A cock inserted in the wall of a pipe, the opening of which indicates whether or not liquid is present or moving therein. A bleeder is sometimes inserted in an oil delivery pipe in order to permit a test to be made as to whether lubricani is or is not being forced there through.
Blister
A tire defect which results from the separation of the tread from the fabric to which it should be secured. Sand frequently enters the space between tread and fabric, through a cut in the former, lifting the tread and causing an external swelling upon the tire, the appearance of which justifies the term.
Synonym: Sand boil, sand wart.
Blower Cooled
A term applied to a motor cylinder which is cooled by air positively circulated about it by means of a blower. The air is usually definitely confined in ducts surrounding the external surface of the cylinder.
Used in contradistinction to “fan cooled” which usually implies that the air is less positively circulated and less definitely directed upon the cylinder walls.
Blow Off
A tire accident characterized by the edge of the bead of the tire freeing itself from its fastening to the rim at some point and the inner tube protruding through the space there formed, usually resulting in the bursting of the tube and sometimes in the whole tire leaving the rim. The safety valve of a steam boiler or the valve through which the boiler may be emptied of water.
Blowout
A tire accident occasioned by a rupture of the casing and the extrusion of the inner tube there through with a resultant bursting of the same.
Blowout Patch
A sleeve made of canvas, rubber fabric, leather or some similar material, designed to stop the hole in a tire casing and to prevent the inner tube from blowing out there through. Such a patch may be applied between the tube and the inner wall of the casing (an inside blowout patch), or it may be strapped or laced over the outside wall of the casing.
Synonym: Emergency tire sleeve.
Blow Torch
A portable torch, usually burning gasoline or alcohol, used to heat the pilot light of a steam car’s burner, and also used in soldering operations.
Body
The degree of viscosity, applied to lubricating oils. Thick viscous oil is said to possess more body than thin oil.
Body, Close Coupled
A form of four or five passenger body in which the rear or tonneau seat is located somewhat further toward the front than usual, frequently well forward of the rear axle, and the front seat is located somewhat fur the back than usual. Both seats are thus included between the axle lines and are rather close together, allowing no room for folding tonneau seats. A trunk platform is sometimes placed at the rear of the tonneau seat.
Body, Fore Door
A body which, in addition to the ordinary side doors that give entrance to the tonneau, is equipped with similar side doors closing the entrance space between the front seat and the dash. These fore doors protect the front seat passengers from dust and cold draughts.
Synonym: Fore door body; vestibule body.
Body, Gunboat
A form of tonneau touring body characterized by the use of fore doors and very high sides, the upper edges of which form a nearly straight horizontal line, nearly coincident with or slightly higher than the top of the hood. A rearward sloping dash is often used and the lines’ of the rear of the tonneau may be curved so as to resemble the stern of a gunboat. Synonym: Torpedo body; flush-sided body.
Boiler, Fire Tube
A form of tubular steam boiler, the end plates of which are connected by a multiplicity of thin metal tubes with open ends. The space around the tubes is filled with water and the hot gases from the furnace pass through the tubes on their way to the external air. The inside surfaces of the tubes being in contact with the hot gases, and their outside surfaces in contact with the water, a free transference of heat to the water is permitted.
Boiler, Flash
A form of steam generator in which there is practically no storage of water or steam, steam being generated by it in accordance with the demand of the moment. It generally consists of a rather massive system of connected pipes or sections which is maintained at a steam raising temperature. Into the passages thereof water is pumped at rates dependent upon the momentary call for steam and is almost instantly vaporized and furnished to the engine usually in a superheated condition.
Synonym: Flash generator.
Boiler Tube
One of the thin walled tubes through which the furnace gases pass in a tube boiler.
Boiler, Water Tube
A form of steam boiler in which the water is confined in coils of pipe or communicating cast sections,which are surrounded by a casing through which the furnace gases circulate. Not much used.
Boiler, Wire Wound
A fire tube boiler the cylindrical shell of which is tightly wound with steel wire in order to give it greater strength against bursting.
Boiler Sheet
The steel plates which form the ends of a fire tube boiler, the upper one being called the crown sheet and the lower one the bottom sheet. The ends of the tubes are expanded into holes drilled respectively in these two sheets.
Boiler Shell
The cylindrical portion of a fire tube boiler into the ends of which the crown and bottom sheets are fastened.
Boot
A covering designed to afford protection from road dirt and water, usually made of waterproof fabric; e. g., the cover placed about a magneto or that hung under the car mechanism.
Boot, Grease
A bag-like receptacle of leather or similar material designed to contain lubricant and to fasten tightly around working parts, thus keeping the same enveloped in lubricant and free from dust. Such a boot permits of some relative motion between the parts enclosed.
Boss
A thickened or otherwise enlarged portion of a mechanical part designed to afford a point of sufficient strength for the attachment of a related part; e. g., the inside of a piston is provided with two diametrically opposite bosses, which are drilled out to receive the ends of the piston pin. They afford sufficient thickness for bearings and serve to distribute the stresses at the pin ends to the relatively thin piston walls. Bottom (v.) Gears which run together without clearance, the points of the teeth of each touching the bottoms of the tooth spaces of the other, are said to bottom. Such gears are pitched too closely and operate with excessive noise and friction.
Bow Separator
A device for holding the bows of a top (q. v.) out of contact and preventing their chafing when the top is folded, consisting of a series of rubber spacers or distance pieces interposed between the bows and strapped in place or of doweled (q. v.) metal distance pieces attached to the bows, which come into contact when the bows are folded and strapped together and hold them apart.
Bow Supporters
A forked, leather lined iron, one of which is attached to each side of the rear of a car body to form a rest H1 which the bows of a folded top fit and are secured by straps.
Bowden Wire
A mechanism used to transmit motion from a controlling device to the part to be controlled thereby, which dispenses with levers, rods and any kind of link work. The direction of motion at the control lever may bear any relation to that of the part moved, and the connecting mechanism may pass around intervening obstacles and take almost any convenient form, being stationary externally. It consists of two parts, a closely coiled, incompressible spiral spring, known as the outer member, and a practically inextensible steel wire cable, threaded through the outer member, which forms the inner member. If the ends of the outer member are fixed so that the distance between them is invariable, a pull applied at one end of the inner member will be transmitted as a pull to its other end, and if both ends of the inner member are fixed, a push applied to one end of the outer member will be transmitted to its other end. It is used to operate spark timers, throttles, carburetor, air controls, muffler cut-outs, etc.
Brake, Air Cooled
A brake, the shoes, drum or band of which are so arranged as to facilitate the transference to the surrounding air of the frictional heat developed in service. The parts are usually ribbed or otherwise formed so as to present a large convecting surface to the air.
Brake, Differential
A brake which acts upon the differential gear of a car. Such a brake may consist of a band which contracts upon a drum forming a part of or secured to the pinion frame of the differential, or it may be a double brake, consisting of two straps or two pairs of shoes, which act respectively upon two drums that are attached respectively to the two main gears of the differential. A form at present not much used.
Brake, Double Acting
A brake, the band or shoe of which exerts nearly the same holding power upon its drum, irrespective of the direction of rotation thereof. Such a brake is thus nearly as effective in checking backward as in checking forward motion of a car.
Brake, Electric
A form of brake sometimes used upon electric vehicles, the principle of which consists in temporarily converting the vehicle motor into a dynamo, and dissipating in electrical heat the energy of motion possessed by the vehicle. In order to apply the electric brake, connections are made by the controller, which short-circuit the motor and the electromagnetic reactions of the induced currents set up therein hold back the armature and, through the transmission gearing, slow down the vehicle.
Brake, Emergency
A brake primarily intended to be used in making sudden stops. The term is used in contradistinction to “service brake». In practice the name is applied to the pair of brakes which is operated by a lever, usually ratchet retained, and which is used to hold a car at rest as well as to stop it in an emergency. In current practice the emergency brakes are usually internal expanding hub brakes. Brake, External Contracting A form of brake the external surface of whose drum is encircled by a band anchored to some fixed part of the car. By means of a toggle or similar mechanism, the band can be contracted upon the drum and thus tend to hold it from turning.
Brake, Foot
A brake or pair of simultaneously acting brakes which are applied by a pedal operated by the driver’s foot. The foot brake is the brake commonly used for slowing down and stopping, in ordinary driving.
Synonym: Pedal brake.
Brake, Front Wheel
One of the two simultaneously acting brakes which act upon the front wheels. Little used in this country at present, but being introduced in Europe. The application of brakes to the front wheels as well as to the rear wheels nearly doubles the braking power of a car, and the use of front brakes tends to diminish danger from skidding when a sudden stop is made. As the front brakes turn with their wheels in steering, their operating mechanism is necessarily somewhat complicated.
Brake, Hand
The brake or pair of simultaneously acting brakes which are applied by means of a hand lever, which is usually provided with a ratchet locking device.
Synonym: Lever brake.
Brake, Hub
A brake which acts upon a drum secured to one of the wheels, the drum being usually an integral part of the wheel hub and frequently bolted through the spokes. Such brakes are employed in pairs; in ordinary practice one on each rear wheel hub, both being simultaneously actuated by means of a single pedal or lever and a suitable connecting linkage.
Brake, Internal Expanding
A brake which consists of a drum secured to a wheel hub or upon a transmission shaft against the inside periphery of which can be applied a band or a pair of shoes that are anchored to a fixed portion of the car. The band or shoes are expanded into frictional contact with the inside of the drum by means of a toggle, cam, wedge or- other equivalent mechanism.
Brake, Metal to Metal
A brake in which a metal band or metal shoes act against a metal drum, the metals being chosen so as to possess a mutual abrasive action. Oil is often used between the frictional surfaces.
Brake, Motor
A form of brake used upon electric vehicles, which acts upon a drum carried upon the armature shaft of the motor.
Brake, Prony
A form of absorption dynamometer (see dynamometer), used in determining the output of motors, consisting of a brake band or a series of brake shoes clamped, with adjustable pressure, upon the face of the motor flywheel and a counterbalanced arm of known effective length, upon which weights can be hung. When the motor is in operation weights are added to the arm until the moment of friction exerted by the brake exactly balances the torque (q. v.) developed by the motor and the horse power delivered is computed by the formula H. P. = 0.0001904 LWS; where L is the effective length of the arm in feet, W the weight acting on the arm in pounds, and the speed of the motor in revolutions per minute.
Synonym: Friction dynamometer.
Brake, Ratchet Retained
A brake, the operating lever or pedal of which is provided with means for locking it in any position in which it is set, so that the brake may be left in a more or less applied condition (especially when the car is left standing).
Brake, Service
The brake, or simultaneously operated pair of brakes, which is adapted to be used in the slowing down and stopping of a car in ordinary driving. The term is used in contradistinction to “emergency brake». The service brake is usually a pedal brake, operated by the driver’s right foot.
Brake, Transmission
A brake which acts not upon a wheel hub drum, but upon a drum secured upon a transmission shaft, which is in motion so long as the car is moving. The effect of such a brake is transmitted to the driving wheels and the road through the intervening transmission mechanism. In practice the transmission brake of a shaft driven car is applied to a drum carried by the driving shaft, located inside of or outside of the gear box. In a double chain driven car, a pair of simultaneously operated brakes act upon drums, usually applied to the two front sprockets.
Brake, Water Cooled
A brake through channels in the shoe or drum of which water is passed from a tank carried upon the car, to prevent the parts from overheating under very severe service.
Brake Anchor
That part of a brake mechanism which acts to prevent the rotation of the band or shoes when they are forced into contact with the rotating drum. The anchor is a rigid support usually fastened at one end to the axle casing (in the case of a wheel brake), and at the other to the operative portion of the brake.
Brake Band
A more or less flexible band, anchored at its ends to fixed supports and adapted to be contracted upon the external surface or expanded against the internal surface of a brake drum, so as to tend to prevent by friction the rotation of the drum. Such a band may- have a metallic frictional surface, or it may be faced with fiber or special fabric.
Brake Beam
An equalizer bar.
Brake Cable
A flexible wire cable, sometimes used to transmit the pull exerted at a brake lever or pedal to the mechanism at the brake itself that forces the band or shoes against the brake drum.
Brake Cam
A cam, forming a part of a brake mechanism, which acts to force the band or the shoes into frictional engagement with the drum.
Brake Drum
A hollow cylindrical metal part, secured axially upon a transmission shaft or upon the wheel hub of a car, adapted to be frictionally engaged by a band or by shoes contracting upon its outside cylindrical surface or expanding against its internal surface.
Brake Equalizer
A device which is applied to brakes that are simultaneously operated in pairs from a single lever or pedal (hub brakes, for instance). Its function is to insure that each brake of the pair shall, under all ‘ conditions, be applied with equal force, so that one wheel may not be braked more violently than the other. A common form consists of a freely supported horizontal lever, to the C centre of which is attached the pull rod from the operating lever or pedal, and to the ends of which are attached the pull rods, which act respectively upon the two brakes.
Brake Housing
The casing which encloses the mechanism of a brake, thus protecting it from water and road dirt, and permitting of its effective lubrication. The housing is usually a thin casting or metal stamping attached to the axle casing (in the case of hub brakes), and closing the opening of the brake drum.
Brake Latch
That portion of a brake that is capable of being locked in position, which engages with a ratchet and holds the brake lever or pedal set in the desired position. It consists of a thumb or ‘toe piece, connected with which is a spring actuated linkage acting to hold the detent in engagement.
Synonym: Brake detent.
Brake Lever
The operating lever by which a brake or pair of brakes is applied.
Brake Lining
A thin strip of material riveted to the working surface of a brake band or shoe, which forms the actual frictional surface that bears upon the drum, some flexible material, capable of resisting abrasion and heat and possessing a high coefficient of friction with the metal of the drum, such as vulcanized fibre, belting or a special non-combustible fabric consisting of asbestos fibre woven on metal gauze, is generally used.
Brake Linkage
The mechanism which transmits the motion of a brake operating lever or pedal to the brake shoes or band.
Synonym: Brake rigging.
Brake Pedal
The operating foot lever or pedal which actuates a brake or pair of brakes.
Brake Pull Rod
The rod or rods which transmit the pull set up at a brake operating lever or pedal to the mechanism at the brake itself which applies the band or shoes.
Brake Quadrant
The fixed sector shaped guide within which moves the operating lever locking ratchet is usually mounted.
Brake Shoe
A block, more or less segmental in form, anchored to a stationary part of the car mechanism, which is adapted to be forced against a revolving brake drum to retard vehicle motion. Brake shoes are usually operated in pairs, through a toggle, cam or wedge action and are generally of metal. They are used chiefly in internal expansion brakes.
Brake Spider
The support for the band or shoe and for the operating mechanism of a brake, generally consisting of a hub secured to the axle casing within or adjacent to the brake drum, provided with several arms arranged to give rigid support to the various operative parts.
Brake Spring
A spring which acts in opposition to the force which applies a brake and removes the band or shoes from contact with the drum when the operating pedal or level is released. Generally a spiral spring.
Brake Toggle
A linkage somewhat of the toggle joint typo, used in a brake to multiply the force exerted by the pull rod so that a very heavy pressure shall result between the band and the drum when the brake is applied.
Braking With the Motor
The employment of the resistance offered by a vehicle motor, when it is not rotating under its own power, but being rotated by the kinetic energy stored in a moving car, to reduce the vehicle speed. The resistance offered is due to the friction of the motor and to the irrecoverable work done by the motor pistons upon the gases in the cylinders. Ordinarily, braking by the motor is accomplished by interrupting its ignition and retaining the clutch in engagement, the lower the gear which is in use the greater the braking effect obtained. Some motors are fitted with special intake and exhaust cams, the use of which temporarily converts a four cycle motor into a two stroke cycle air compressor with variable compression, thus increasing the braking effect, a valve being provided for shutting off the carburetor and admitting air only to the cylinders, with resulting economy in fuel.
Braking Surface
The actual surface of contact between a brake drum and the band or shoes which are applied to it; c. g., if a brake drum is 12 inches in external diameter and the width of the band which contracts upon it is 2 inches, the braking surface will be I27j-x2 = 75 square inches, assuming that the band completely encircles the drum.
Brass
The fixed bronze or composition lining of a bearing support which forms the actual surface upon which the supported shaft rotates or slides. A bearing bushing (q. v.).
Braze, v.
To join by brazing, which process consists of closely abutting the cleaned edges of the parts to be joined, heating them intensely, usually by means of a blast lamp flame, freeing the abutted surfaces of oxide by means of a suitable flux (usually borax), and melting into the junction a special brass or spelter, usually furnished in a granular form, or in that of wire. The spelter unites with the surfaces of the parts and forms a joint of considerable strength. The process was formerly largely used for uniting parts to the steel tubing used for axles.
Breather
A vent tube introduced into the enclosed crank case of a gasoline engine to permit of the equalization of the air pressure therein, which would otherwise fluctuate considerably with varying positions of the pistons, absorbing some energy and perhaps interfering with lubrication. The breather rises vertically from the crank case, and its open upper end is usually provided with baffle plates to prevent the escape through it of lubricating oil from the crank case. It is often used as a filler tube.
Breech Block Joint
A special form of threaded joint, sometimes applied to parts that require to be screwed into or onto each other quickly. Four segmental portions of both the male and female thread are cut away so that the pieces may be slid into their final engaged positions, one upon the other, by matching the cut away portion with the uncut portion of the other and then rotating one relatively to the other through one-eighth turn, which brings all the threads in engagement and locks the parts securely together.
Bronze
A reddish alloy, of variable composition, used for bearing bushings (,see bushing bronze) and minor structural parts, differing from ordinary brass in its large copper and tin and low zinc content. The following may be taken as an average bronze specification: Copper, 84.0 per cent.; tin, 12.0 per cent; zinc, 3.0 per cent, and lead, i.o per cent. The term bronze is frequently applied to any red brass, a typical specification for which is: copper, 85.0 per cent.; tin, 5.0 per cent.; zinc, 5.0 per cent.; lead, 5.0 per cent.
Brush, Contact
A conducting part used to complete the electrical circuit between a stationary and a moving element of an electrical device. Brushes are used to convey the current between the windings of the rotating armatures of magnetos, dynamos and electric motors, and the stationary portions of such machines, and for making connection between the rotating and non-rotating portions of timers and distributors. Brushes are usually made of wear-resisting metal or of copper-plated carbon.
Brush Holder
A device adapted to hold one end of a brush securely but somewhat flexibly in contact with a moving element of an electric circuit, and supplied with a binding post or other means by which a relatively fixed portion of the external circuit is connected to it and thus to the brush. In ignition practice it is usually a fixed brass tube, in which a cylindrical carbon or metal gauze brush is closely fitted, but capable of sliding therein, under the influence of a spiral spring, so that wear between the end of the brush and the rotating part may automatically be taken up and a reliable contact be secured.
Brush Spring
A spring employed to press a brush holder into positive contact with the moving element with which it is to maintain electrical connection.
Buckling
The bending or deformation of a plate of a storage cell, generally caused by the discharge of current through it at an excessive rate or by its over-discharge. Under these conditions the active material in the interstices of the grid swells and shrinks excessively, and this causes the buckling of the grid. A permanent set or deformation produced by excessive pressure, in frames, boiler tubes, headers or in any other plate, tube or member.
Build Up (v.)
To attain a magnetic condition under the influence of an electric current. A small but appreciable period of time elapses between the commencement of flow of an electric current through the winding of an electromagnet and the attainment of full magnetism by its core. In the case of spark coils, for instance, current must be allowed to flow through the primary winding for an adequate length of time before each ignition is called for, or otherwise a full discharge will not take place in the sparking circuit and only a weak spark occur, because of the failure of the magnetism fully to build up in the time of contact allowed.
Bumper
An elastic member, placed between two members which may strike one another when in action, in order to cushion the resulting shock when this occurs. A metal spring or a properly shaped piece of rubber, leather or similar material is generally used, it being fastened to one of the parts so as to be interposed between the two.
Synonym: Buffer.
Bumper, Collision
A strong horizontal bar, carried crosswise of and at a little distance from the front or rear end of a car, which is guided so as to be capable of a limited movement along the car’s axis of length, and which is kept pressed away from the car by heavy springs. In event of collision between the car and another vehicle or fixed object, the energy of the collision is partly absorbed in compressing the springs and the liability of breakage of car parts is reduced.
Burn Out (v.)
To destroy the conductivity of or to break down the insulation of a conductive portion of an electrical device by an accidental electrical discharge, or by the accidental application of excessive electrical heat. As applied to coils used in ignition, a burnout usually results from a puncturing of the insulation and a consequent short circuit or from the passage of an excessive current, which either melts off the conductors, or melts, or chars the insulation, resulting in a breakdown and short circuit. To loosen the tube ends from the sheets of a steam boiler by the application of a fire to it when it is insufficiently supplied with water.
Burner
The device which produces the gas fire for heating the boiler of a steam car. It consists of a means for vaporizing the pressure fed liquid fuel, of mixing the fuel vapor with air and of distributing the flame produced over the exposed area of the boiler.
Burner Casing
A metal housing surrounding the burner of a steam vehicle and the space between it and the boiler, confining the heat to its proper channels and protecting the flame against air currents.
Burner Jet
The jet of a steam vehicle burner, through which the liquid fuel is sprayed, under pressure, in a finely divided condition, previous to its mingling with air to form a perfectly combustible mixture.
Burner Plate
A perforated metal plate, placed under the boiler of a steam car, through which the combustible mixture rises and burns in a multiplicity of flames.
Burner Valve
A valve usually of the needle type, inserted in the fuel feed pipe and used to regulate the flow of liquid fuel to the burner jet of a steam vehicle. Such a valve may be manually operated or under the control of an automatic fire regulator (q. v.).
Bushing, Bearing
A lining, fixed in a bearing support and in which a rod or shaft slides or rotates. It is usually made of ‘anti-friction metal and is generally capable of renewal or adjustment after wear has taken place, so that looseness between the rod or shaft and its support may be corrected.
Synonym: Bush.
Bushing, Babbitt
A bushing made of babbitt metal, which may either be cast on the shaft in the bearing support, and scraped to fit the shaft, or which may be cast separately and applied to the bearing support and shaft, or cast in a bronze liner which is applied to the bearing support.
Bushing, Bronze
A bearing bushing made of bronze, which metal, if of proper quality, possesses a high degree of wear resisting and anti-friction qualities, when used to carry steel shafts.
Bushing, Composite
A bushing, the bearing surface of which is composed of alternate segments of a soft and of a harder anti-friction metal, usually babbitt and bronze.
Bushing, Compressed
A bushing the metal of which has been rendered dense and wear resisting by compression, usually by hammering of its surface.
Bushing, Die Cast
A babbitt bushing, the metal of which has been rendered dense, hard and smooth by casting it under pressure in a die or mold. A very fine finish is thus attained and the bushings thus produced are interchangeable.
Bushing, Insulating
A lining or thimble of insulating material threaded over an electrical conductor and fixed in a support through which the conductor is to pass, so that leakage of current from the conductor to its support may be prevented.
Bushing, Split
A bushing which, instead of being a complete hollow cylinder, is longitudinally split into halves. This construction allows of ready removal of the shaft and of some adjustment for wear of the bushing by filing away the abutting edges of the bushing halves, or by the removal of shims (q. v.) which have been placed between the edges so as to keep them slightly separated.
Butterfly Nut
A form of thumb-nut intended to be turned without a wrench, having two wing-like projections formed integrally with the threaded centre, convenient to be grasped by the fingers.
Synonym: Wing nut.
Butterfly Valve
A form of valve applied to a pipe, consisting of a circular damper capable of nearly or quite filling the pipe bore and a spindle secured to a diameter of the damper, which passes diametrically through the walls of the pipe and bears therein. A common form for throttle valves and carburetor air valves.
By-Pass
An alternative path for a fluid which is being circulated in a system, used as a means of regulating and directing the flow, e. g., in a pumping system supplying water to a boiler, there is inserted in the pump delivery pipe, between the pump and the boiler, a pipe which leads back to the suction side of the pump. This pipe can be entirely closed, in which case all the water pumped flows to the boiler, or it can be partly or fully opened. If the by-pass is partly closed, a portion of the water will go to the boiler and the remainder will pass back to the pump through it. Used on steam cars and in pressure lubricating, and fuel supply systems, in which a pump is operated continuously.
By-Pass Valve
A valve inserted in a by-pass to regulate the degree of obstruction to flow there existing and thus to regulate the rate of supply of fluid from a constantly operated pump to some point in the system.
