Abstract: A mixer which provides axial flow in a non-uniform flow field, such as may be established by gas which is sparged into a medium being mixed in a tank, and provides large axial flow volume without flooding and withstands variable loads on the blades thereof, thereby providing for reliable operation. The mixer impeller is made up of paddle shaped blades, which near their tips (e.g., at 90% of the radius of the impeller from its axis of rotation) are of a width at least 40% of the impeller'a diameter. The blades also having camber, twist and flat sections. The flat sections being at least in the center area of the base of the blades. The hub for attaching the blades to the shaft of the mixer has radially extending arms with flat surfaces. The base of the blades are spaced from the shaft to define areas therebetween.

Abstract: A calorimetry system for measurement of the heating value of coal, having a combustor 24 and a mixing unit 30 wherein heat from combustion gases is transferred to air. The system has a gravimetric feeder 64 for providing coal at a measured mass feed rate; the coal including any moisture present therein. The coal is pulverized in an air-driven mill or pulverizer 14 which is fed coal from the feeder and is separated by a cyclone separator 16 into two streams; one carrying coal and air mixed together in a controlled ratio to the combustor. The air which drives the separator, together with fines of the coal and moisture is fed to an afterburner 26 of the combustor so that the thermal dynamics of the entire coal stream is involved in the heating value measurement.

Abstract: A calorimetry system for measurement of the heating value of coal having a combustor 24 and a mixing unit 30 wherein heat from combustion gases is transferred to air. The system has a gravimetric feeder 64 for providing coal at a measured mass feed rate; the coal including any moisture present therein. The coal is pulverized in an air-driven mill or pulverizer 14 which is fed coal from the feeder and is separated by a cyclone separator 16 into two streams; one carrying coal and air mixed together in a controlled ratio to the combustor. The air which drives the separator, together with fines of the coal and moisture is fed to an afterburner 26 of the combustor so that the thermal dynamics of the entire coal stream is involved in the heating value measurement. Instrumentatoin measures the flow rates of cooling air, primary air which carries the coal streams into the combustor and secondary combustion air as well as the mass flow rates of the coal into the combustor as measured with the gravimetric feeder.

Abstract: Coupler control system for railway vehicles that provides isolation of the electric and pneumatic lines of a rail vehicle from its corresponding electric and/or pneumatic intervehicle interface when that end of the vehicle is in an uncoupled condition. A combination proximity sensor and switch is positioned within the mechanical hook coupling housing so as to sense the actual engagement of the mechanical hooks of a pair of vehicles. The switch then closes and becomes operative to initiate a coupling cycle during which the onboard electric and pneumatic lines are coupled to the associated electric and pneumatic interfaces to provide continuity with the vehicle to which it is coupled. Included in the circuitry for the sensor switch is a diode circuit arranged to permit looping of the sensor switch output across the electric interface onto the adjacent car and back through the interface through the use of only two interface connector pins per interface.

Abstract: A level sensor system for liquids and liquid slurries utilizes a capacitive probe which extends longitudinally into a liquid or liquid slurry containing vessel, and which may contain inner and outer sensors spaced from each other in an assembly with a flow control screen at its lower end to permit egress of liquid and exclusion of the solid slurry material, thereby enabling both liquid and slurry level to be determined. The capacitance presented by each sensor is converted into a digital output in repetitive cycles having a reference phase, where a reference voltage is generated by charging a reference capacitor while a counter is registering counts and until a pre-determined count is reached, and in a computing phase while counts are accumulated until the capacitance presented by the probe charges to a voltage equal to the reference voltage.

Abstract: The apparatus of this invention is a broken rail detection system that detects rail and/or rail breaks in dark territory track sections, i.e. track sections that do not have signalling systems. In one embodiment of this invention a system is disclosed in which a communications link exists between the ends of the track sections and in another embodiment of this invention no communications link exists between the ends of the track sections.

Abstract: A broadcasting arrangement includes a source of signals to be transmitted which is subject to distortion in the event that signals are reflected. An antenna is adapted for radiating all the signal applied to a polarization sensitive input part with a particular polarization. The antenna is mounted on a tower. A waveguide is coupled to the source of signals and to the input port of the antenna. If the waveguide is circular waveguide, the windload on the tower due to wind loading of the circular waveguide is low, but flexure which occurs results in polarization changes which causes signals applied to the antenna input port to be reflected, thereby reducing radiated power and causing distortion. If the waveguide is rectangular, the wind loading is high and the tower must be more sturdy and therefore more costly than for circualr waveguide. A truncated circular waveguide is used which has a wave propagation channel defined by a cylinder and a pair of parallel longitudinal plates in the cylinder.

Abstract: A reversible spring return cylinder actuator having a pair of piston rods extending from a common spring load piston to the exterior of the housing. In a non-pressure position of the piston, one of the piston rods extends further from the housing than the other. Either piston rod and either end of the housing can be mounted to a device to be actuated so that the same actuator can be used to define a non-pressure extend or retracted actuator without disassembly of the actuator.

Abstract: A mixing system for dispersing gas or other fluids in liquid which may have a solid suspension so as to improve mass transfer to the liquid or its solids suspension while maintaining a low pattern which is substantially axial (up and down) in the tank containing the liquid thereby also facilitating mixing (blending) utilizes an (unshrouded) axial flow impeller which provides the desired single stage axial flow downwardly to the bottom of the tank and upwardly along the sidewalls of the tank with radial flow confined principally to the bottom region of the tank. A sparge system which releases the gas or other fluid in the region at the bottom of the tank where the flow is predominantly radial allows attainment of gas rates with complete dispersion of gas throughout the tank which rates are much higher (about four times as great) as when conventional sparge systems are used with axial flow impellers.

Abstract: A dark field target design system for alignment of semiconductor wafers is disclosed. The system utilizes improved target designs which provide for improvement in the alignment of semiconductor wafers.

Abstract: An audio frequency (AF) track circuit whereby a railway track tuned loop transmitter operating in a dual resonant mode, for handling, two signal frequencies, can be coupled to the rails. Each frequency is conducted through a tuning unit having series and parallel branches tuned to each frequency. The track circuit using the tuned loop transmitter eliminates DC return current imbalance effects while maintaining suitably high track circuit shunting sensitivity.

Abstract: Compensation for the temperature sensitivity of the output of a potentiometrically operated ISFET probe whose drain-source voltage and drain-source current are held constant is provided by using a Nernstian temperature correction of the difference between the ISFET output and the isopotential voltage of the probe and offsetting the resulting difference by the isopotential pIon value. An ISFET/NISFET pair provides a cancellation of variations due to manufacturing.

Abstract: A compressed single side band communication system and method in which the audio signal is compressed prior to pre-emphasis and thereafter summed with a pilot tone for further compression prior to transmission. Initially, only the pilot tome is transmitted at full rated power to aid in acquisition of the signal by the receiver. Thereafter, the transmitter ALC is disabled and the pilot tone is attenuated. The receiver adjusts the frequency characteristics of the pilot tone filter and phase lock loop filter in the detector as a function of lock-up. The delay after loss of lock-on in reverting to wide band pilot tone and wideband loop filters is varied as a function of signal strength. The pilot tone may be frequency modulated for tone coded squelch, with the modulating source being located in the return end of the phase lock loop filter. A unique filter is provided to insure acquisition of the pilot tone.

Abstract: A fluid brake system has a brake pipe, a control valve device, a brake cylinder and a brake rigging, and in addition, a handbrake pipe, a protective device, a fluid pressure releasable spring handbrake cylinder, and a manually operable handbrake device for selectively governing brakes of the brake rigging under varying conditions, as when air supply is disconnected from a train. A moveable fulcrum in the manual handbrake device permits manual release of spring applied handbrakes in combination with a resetable toggle locking connection to a handbrake rod.

Abstract: A slack adjustable operator for a spring applied disc brake has a spring motor operating a disc brake through a tubular pushrod having an over-running clutch permitting axial movement of the pushrod in a brake application direction, but not in a brake releasing direction. The over-running clutch operates in longitudinal load roller slots in the outer periphery of the pushrod and having a ramp load roller retaining ring slidable laterally on the outer periphery of the pushrod, the retainer ring being retained in a stepped bore of a housing to be laterally operable, along with longitudinal operation of the pushrod for brake release only to an extent to provide normal clearance for pads of the brakes, this limitation being effective to initiate threaded slack adjustment of the pushrod to compensate for wear of the brake pads.

Abstract: A cover assembly apparatus dimensioned and configured for engagement with an associated conduit body having an opening for access to the interior. The apparatus includes a generally plate shaped member, a bow shaped member having flanges extending from the extremities thereof, the flanges dimensioned and configured for engagement with an interface of the associated conduit body, the bow shaped member having a convex side thereof disposed in abutting relationship to the plate shaped member, and apparatus for urging the flanges against respective portions of the plate shaped member to cause the bow shaped member to be less bowed and thus to have a greater length intermediate length as measured between the respective flanges thereof.

Abstract: Doorbell mechanism that employs only one solenoid to achieve both single tone and double tone operation. The solenoiod has a split coil with the full coil being employed for double tone operation and a portion of the coil being employed for single tone operation.

Abstract: A transformer includes first and second coils which are generally cylindrical and having an outer circumferential surface, an inner diametral surface and first and second axial extremities. Shielding is disposed around the coils comprising a web shaped metallic, non-magnetic, electrically conductive generally rectangular first member. The first member has a first portion extending about substantially the entire inner diametral surface of the coils and has a plurality of tab shaped portions extending respectively about a substantial portion of each of said first and second axial extremities. A second non-magnetic, electrically conductive metallic member extending over substantially the entire circumferential extent of each coil.

Abstract: A safety system for hydraulic brakes in a train brake system wherein a spring biased spool valve controls delivery from a hydraulic fluid source to at least two sets of spring applied hydraulic brake actuators and wherein said spool valve is also biased by the fluid pressure delivered to said two sets of brake actuators and upon a rupture in a brake line delivering fluid to one brake actuator, which causes a lowering of a fluid pressure force on the spool valve, causes the spool valve to shut off the delivery of fluid to the ruptured line to allow the spring applied hydraulic brake actuator to engage the applied brake.

Abstract: A mounting for a bearing which comprises a cavity which has at least a portion thereof formed in a spherical section and another portion of the cavity is in the form of a groove extending outwardly from the spherical section. Thus, either a bearing having an external envelope that is a sphere or a cylindrical section may be installed in the cavity.