Abstract: To increase the output voltage of a conventional rectifier bridge, one winding of an autotransformer is connected across a pair of a-c input terminals of the bridge through a thyristor which is turned on only when an output voltage increase is desired, and an extra diode is used to connect the other autotransformer winding to one of the d-c output terminals so that the boost voltage induced in the latter winding is added to the input voltage.

Abstract: For connecting the d-c terminals of a voltage-source inverter to a direct current (d-c) power source, a d-c link capacitor is connected directly between the d-c terminals, a line capacitor is connected in parallel with the d-c link capacitor, and a series inductor is connected between the line capacitor and the source. A dynamic brake resistor and an electric power chopper are connected in series with one another across the line capacitor. Between the two capacitors, no inductance is provided but a resistor is inserted in the braking current path during electrical braking operation of the inverter.

Abstract: A method of adjusting the weight distribution of a locomotive having a pair of interchangeable 3-axle asymmetrical truck assemblies comprising loading the locomotive body with its normal supply of fuel, water, etc.

Abstract: A rotatable member having multiple discrete positions between opposite ends of a normal path of movement is provided with two (or three) parallel, encoded tracks having different patterns of distinct, serial sections. These tracks cooperate with relatively stationary probes of a position sensor. As the rotatable member moves from position to position, the sensor will produce a family of two (or three) separate binary signals that changes states as the probes detect boundaries between successive sections of the tracks with which they respectively communicate, and the patterns of the encoded sections are so selected that the sequence of state changes when the rotatable member is approaching a predetermined mid position will differ from the sequence when the member is moving away therefrom.

Abstract: A variable speed 3-phase a-c motor is connected to a 3-phase source of alternating voltage via a plurality of controllable solid state electric valves which are so arranged and controlled that motor speed can be reduced by skipping selected cycles of the source voltage. For half speed operation 12 valves are arranged to interconnect the source and motor phases, and over two consecutive periods of the source voltage six separate, uniformly spaced "firing windows" are selected during which the conducting states of different pairs of these valves are initiated in a predetermined pattern that results, in each phase of the motor, in a double-pulse current waveform having one-half the fundamental frequency of the source voltage.

Abstract: A fuel injection system particularly adapted for injecting coal slurry fuels at high pressures includes an accumulator-type fuel injector which utilizes high-pressure pilot fuel as a purging fluid to prevent hard particles in the fuel from impeding the opening and closing movement of a needle valve, and as a hydraulic medium to hold the needle valve in its closed position. A fluid passage in the injector delivers an appropriately small amount of the ignition-aiding pilot fuel to an appropriate region of a chamber in the injector's nozzle so that at the beginning of each injection interval the first stratum of fuel to be discharged consists essentially of pilot fuel and thereafter mostly slurry fuel is injected.

Abstract: A method of insulating a field coil of an electric traction motor, comprising the steps of encapsulating the coil in flexible ground insulation, temporarily mounting the insulated coil on a field pole piece, wrapping heat shrinkale material around the perimeter of the insulated coil, said material being so composed, oriented, and applied as to shrink irreversibly, when subsequently heated, in a direction tending to constrict the whole outside perimeter of the insulated coil, attaching the base of the pole piece to a concave surface of the magnet frame of the motor in a manner that compactly clamps the coil between the frame and an overhanging distal end of the pole piece, heating the perimeter wrap so that it shrinks appreciably and tightly binds the underlying ground insulation, thereby counteracting any tendency of the ground insulation to become slack on the outside of the coil when the coil was clamped in place, and filling any remaining voids inside the ground insulation with varnish or resin in a conven

Abstract: For sealing the axle opening in a traction motor gearcase on the motor side thereof, an annular member of elastomeric material has a sleeve portion that is adapted to be clamped to a motor-supporting axle bearing thrust flange and a radially outwardly projecting flange portion that is adapted to fit inside an annular groove formed in an edge of the gearcase sidewall that surrounds the hub of an axle gear adjacent to the thrust flange. The seal further comprises a reinforcing ring having concentric outer and inner sections: the outer section is attached to the flange portion of the annular member to ensure a tight fit in the aforesaid groove, and the inner section extends from the groove to within close proximity of the axle gear hub and forms, with the axle-gear end of the sleeve portion, an annular trough for collecting axle bearing lube oil that escapes through the gear hub-thrust flange interface.

Abstract: The propulsion control system of a diesel-electric locomotive includes means responsive to the respective temperatures of the coolant and the lubricant of the locomotive engine for automatically indicating that the locomotive is in a tunnel if the coolant temperature exceeds an abnormally high magnitude and is higher than a variable reference level that depends on the lubricant temperature. When a tunnel is thus detected, the conventional overtemperature-responsive deration function of the propulsion control system is temporarily suppressed until the coolant temperature rises to a threshold that is higher than the preset overtemperature threshold at which deration is normally initiated.

Abstract: An asbestos-free, unitary insulating member comprises two juxtaposed layers: a first layer of refractory material, and a thicker layer of thermoset resin filled with glass fibers. The first layer was fully cured separate from the second layer, and its inboard side has a relatively coarse surface. The two layers were joined to one another concurrently with the resin in the second layer being cured under pressure in a heated mold, whereby some of the resin penetrates the interstices of the coarse surface of the first layer to form a strong interlayer bond.

Abstract: To detect any abnormal loss of a feedback signal in an electric power system wherein a plurality of feedback signals are respectively derived from various system quantities, such as voltage and current, and are used as inputs to a controller that regulates the output of a controllable source of power, the controller is arranged to estimate the desired value of the system quantity from which a first feedback signal is derived, to compare the estimated desired value with the actual value of the same quantity (as indicated by the first feedback signal), and to signal a malfunction if this comparison reveals that the first feedback signal is faulty.

Abstract: In a diesel-electric locomotive, the power demand of electrically driven auxiliary equipment is automatically increased in response to the temperature of the diesel engine falling to an undesirably low level so as to load the engine when idling and thereby cause it to produce extra heat which prevents abnormal wear and excessive fuel consumption.

Abstract: The propulsion control system of a diesel-electric locomotive includes means responsive to the rotational speed and the gross horsepower of a locomotive engine for controlling the rate at which traction load is added to the engine, when more load is called for, so that the loading rate will increase (between predetermined minimum and maximum limits) as the product of speed and horsepower increases. The loading rate is also increased in response to the ratio of combustion air to diesel fuel increasing above a predetermined no-smoke threshold.

Abstract: For starting a rotatable 3-phase a-c electrical machine of the synchronous type, the stator windings of the machine are connected to an electric storage battery via a controllable electric power converter, and the d-c field winding is connected in series with the stator windings by inserting it in the load current path between the converter and battery. Field weakening resistance is connected in parallel with the field winding. The converter includes a plurality of electric valves (thyristors) that are cyclically turned on in a predetermined sequence in synchronism with alternating voltages developed at the line terminals of the stator windings.

Abstract: A multiple turn coil adapted to be inserted in a slot of a rotor in a dynamoelectric machine is formed by a bundle of individually insulated parallel bars of electroconductive material arranged close together and surrounded, in the vicinity of each slot section of the coil, by a pre-formed tube of substantially non-compressible, non-thermoplastic dielectric material (e.g., polyimide film), the wall of which is thin and flexible enough to bend in any plane and smooth enough to permit substantially unfettered longitudinal expansion and contraction of the insulated conductors inside the tube. Inside the coil a cross-shaped member of the same dielectric material enhances the turn-to-turn insulation.

Abstract: In a diesel-electric locomotive, maximum speed of the diesel engine is automatically limited as a function of the temperature of the engine lubricating oil so as to prevent damage to the engine, to the engine-driven lube oil pump, and to the external components of the engine lube oil system when the oil is relatively cool and hence very viscous.

Abstract: In a 3-phase third harmonic auxiliary impulse commutated electric power inverter the d-c terminals of which are connected, via a circuit having appreciable electrical inductance, to a voltage source comprising a battery, the commutation capacitor is precharged by cyclically manipulting the conducting periods of selected main and auxiliary valves of the inverter so that a series of discrete pulses of capacitor charging current flow from the battery through a path comprising the aforesaid circuit, part of the inverter load circuit, and the capacitor, with alternate pulses of current traversing the capacitor in one direction and intermediate pulses traversing it in the opposite direction. Such action continues for a sufficient number of cycles to "ring up" the capacitor to a voltage magnitude more than five times higher than the battery voltage.

Abstract: In a 3-phase third harmonic auxiliary impulse commutated electric power inverter, during a commutation interval the firing signal for the oncoming main valve of the inverter is delayed for a programmed interval of fixed duration after the commutation capacitor voltage changes polarity, whereby the peak voltage on the capacitor can automatically vary with the magnitude of load current.

Abstract: The magnitudes of currents in the armature and field windings of a separately excited d-c motor are compared, and a fault signal is produced in response to the field current magnitude either rising above a first reference level (which varies as a first predetermined function of the armature current magnitude) or falling below a second reference level (which varies as another predetermined function of the latter magnitude).

Abstract: A variable speed 3-phase a-c motor is connected via a plurality of controllable bidirectional switches to a 3-phase source of alternating voltage having a variable fundamental frequency (f) and an rms magnitude (v) that varies with f, and the switches are suitably arranged and controlled so that motor speed can be reduced by skipping selected cycles of the source voltage. When operating at a fraction of full speed, the magnitude-to-frequency ratio of motor voltage is maintained substantially the same as at full speed by varying the "firing angle" at which the switches start conducting current so as to minimize any deviation of the rms magnitude of the motor voltage from the product of v times said fraction.