Abstract: A fuel vapor entrapment device, during fueling of a motor vehicle fuel tank, traps escaping fuel vapors so as to enhance vacuum-assisted vapor recovery system operation. By deflecting fuel vapors and capturing them temporarily until their removed to a vapor storage tank, the device substantially prevents the escape of fuel vapor into the atmosphere and enables the vapor recovery system to capture a higher percentage of escaping fuel vapor. During the fueling process, the fuel entrapment device encircles the vehicle tank filler port, thereby forming a vapor containment area from which fuel vapors are removed, and prevents the ingestion of excessive ambient air into the vapor recovery system. A vacuum relief hole permits the ingestion of a limited amount of ambient air so as to prevent the build up of excessive negative pressure and avert vehicle fuel tank collapse during vacuum-assisted vapor recovery operation.

Abstract: A method of modifying a digital representation of an image in which digital data defines the content of pixels of the image. The method comprisesa) determining whether a predetermined degree of compression can be achieved if data defining a block of pixels is compressed by applying a predetermined compression algorithm; and, if not,b) discarding a portion of the data in the block, andrepeating steps a and b on the most recently modified block until the predetermined degree of compression is achieved, and generating a compressed version of the image.

Abstract: An improved nut fastener is utilize with a back-up plate to perfect a bolted flange joint. The fastener includes a cage having a planar body affixed to the back-up plate in bearing engagement with a surface thereof. Opposed sides upstanding from the cage body are configured to loosely capture a spherical faced washer, a spherical faced nut, and a nut anti-torque collar in self-aligning relation with a joint bolt hole. An extension of either the cage body or the collar is configured to engage the back-up plate in a manner to inhibit rotation of the cage.

Abstract: A digital-to-analog conversion circuitry is provided wherein a switching network is adapted to couple, or decouple, a selected one, or ones, of a plurality of identical current sources to, or from, an output bus selectively in accordance with the digital word being converted to produce an output current through an output bus having a level related to such digital word.

Abstract: A subsurface Zener diode is provided wherein a semiconductor has formed thereon spaced apart anode and cathode regions of opposite type conductivity, such regions having opposing surface portions, and disposed beneath a surface of such semiconductor a buried region of conductivity type the same as one of such regions, such buried region extending laterally through the spaced apart regions, one of the spaced apart regions having an opposing surface portion thereof formed with a portion which protrudes towards the opposing surface portion of the other one of the spaced apart regions. With such arrangement, an electric field produced between the spaced apart regions becomes concentrated at the protrusion with the result that Zener breakdown occurs repeatedly at the same point in the semiconductor thereby reducing long term drift. Also, a Kelvin buried Zener diode is provided by forming a second laterally spaced anode region with the cathode region disposed between the pair of anode regions.

Abstract: A comparator circuit is provided for producing a voltage across the base and collector electrodes of an output transistor to drive the output transistor to either a conducting condition, or a nonconducting condition, selectively in accordance with an input signal. A switching circuit, responsive to the input signal, is coupled between a current source and the base electrode of the output transistor for electrically coupling the current source to the base electrode of the output transistor when the output transistor is driving from the conducting condition to the nonconducting condition and for electrically decoupling the current source from the base electrode of the output transistor when such output transistor is driving from the nonconducting condition to the conducting condition. With such arrangement, when the switching circuit couples the current source to the base electrode of the output transistor, the current source provides a discharge circuit for base charge in the output transistor.

Abstract: A digital-to-analog conversion circuitry is provided wherein a switching network is adapted to couple, or decouple, a selected one, or ones, of a plurality of identical current sources to, or from, an output bus selectively in accordance with the digital word being converted to produce an output current through an output bus having a level related to such digital word.

Abstract: A differential amplifier having a pair of common base transistors with emitter electrodes adapted for coupling to an input signal and collector electrodes coupled to a voltage source through a pair of resistors. A pair of clamping diodes is connected, in opposing polarity, across the collector electrodes to limit the differential voltages produced at such collector electrodes. A bias circuit is provided between the voltage source and the common base electrodes of the transistors to provide a bias voltage at the common base electrodes which is as close to the voltage of the voltage supply without biasing either one of such pair of transistors into saturation. The bias circuit includes a first resistor connected between the voltage source and the common base electrodes and, in parallel with such first resistor, second resistor and serially connected diode.

Abstract: A turbofan engine fan blade made of composite material, and a method of making the fan, are taught. The fan blade essentially comprises an airfoil section having a root end and made of a plurality of bonded plies of composite material which are splayed and which are in a staggered condition at the root end; a two-piece platform section made of titanium or of aluminum, with one piece of the platform on each side of the airfoil section; and a steel outsert section which holds and secures the platform section to the airfoil section, with the outsert section having a triangular shaped cavity located at the root end of the airfoil section, between the splayed and staggered plies of the airfoil section. Among other advantages, the cavity eliminates the "insert plies" (or wedge) used in the prior art and the inherent disadvantages associated with such use.

Abstract: A turbomachinery rotor comprising a rotatable hub and a composite blade attached to the periphery thereof. The blade comprises a plurality of bonded filament laminates extending between, and wrapped around, a pair of hollow, semicylindrical inserts at the blade root. The laminates are bonded to the inserts so as to form a cylindrical blade root profile for insertion into a complementary cylindrical groove in the periphery of the hub. A slotted pin is positioned within the inserts to prevent the root from collapsing under loadings and to retain the blade in the hub.

Abstract: A turbomachinery blade platform comprising a pair of complementary platform halves, each having an outer flow path defining shroud adapted to extend generally laterally of the blade. An inner flange on each platform half, also extending generally laterally of the blade, is retained in a cooperating slot formed within the support structure retaining the blade. A structural member extending between the shroud and the flange is contoured to conform to an overlapping wedging surface disposed about the blade airfoil surface. The platform is thus provided with redundant retention by both the blade and by the blade support structure.