Abstract: A rotary mower wherein tall vegetation is cut by selectively exposing a front opening in the housing of the mower, which in turn exposes a portion of a rotating cutting blade.

Abstract: A device for detecting a break in one of two tensioned threads merging into a yarn comprises a support on which a guide member with two yarn-bracketing pins is pivotable about a horizontal axis. The guide member is provided with a hole penetrated by a stud of smaller diameter having a head with two or more chordal ridges of different peripheral widths each of which, when brought into a horizontal position above the stud axis, contacts a rabbet on the guide member disposed below its center of gravity to hold that member in a metastable position from which it is dislodged by a difference in the tensions of the two threads. When that difference surpasses a certain threshold, upon rupture of one of the threads, the guide member tilts into an unstable position from which it gravitates through substantially half a turn into an inverted stable position, thereby entangling the remaining intact thread with its pins and inhibiting the advance thereof so that it, too, will rupture.

Abstract: A novel synthetic yarn is disclosed which comprises fibers of different lengths (as specified). At least three groups of synthetic fibers are present in the yarn, with the synthetic fibers within each group being substantially uniform in length. The substantially uniform length of each group of synthetic fibers present in the yarn differs from the substantially uniform length of the synthetic fibers in the other groups. The use of such mixtures of fiber lengths in a synthetic yarn enables the yarn to exhibit physical characteristics such as high bulk which more closely resemble the characteristics of natural fiber-containing yarns. Fabrics having improved physical characteristics may also be produced from the novel synthetic yarns disclosed.

Abstract: This disclosure relates to a link band, in particular a watch wrist band, a bracelet or the like which includes a plurality of links defined by opposite longitudinal edges, opposite transverse edges, and opposite upper and lower surfaces; adjacent links being articulately interconnected by projections received in recesses, the connection between an end of a projection and an associated recess having an axis of rotation located contiguous adjacent longitudinal edges and upper surfaces of adjacent links, and the articulating connections being such as to absorb longitudinal forces imparted to the link band when in use and to also lock adjacent links together against unlocking movement of the links perpendicular to a longitudinal plane of the link band.

Abstract: A cavity is defined between the rotating and stationary parts of a gas turbine engine through which cavity air is circulated. Upstream and downstream seals are disposed at opposite ends of the cavity for regulating the circulation of air flowing into and out of the cavity. A cooling air circuit for the engine rotor is provided which channels air from the stationary portion of the engine to the rotor through the cavity therebetween. The rotor air cooling circuit includes an inducer chamber where the cooling air is accelerated and transferred to the engine rotor. The inducer chamber is defined by two additional seals which, in conjunction with the other cavity seals define chambers upstream and downstream of the central inducer chamber. A bypass circuit directs the air circulated within the upstream chamber directly to the downstream chamber (bypassing the inducer chamber) so that the coolant air flowing through the inducer chamber is not contaminated with the air circulated between the engine rotor and stator.

Abstract: This invention relates to the mounting and support of fuel nozzles for gas turbine engines with the capability of removal externally and internally so that external removal capability negates the necessity of turbine and combustor teardown and allows access without engine removal from the aircraft.

Abstract: A waste heat recovery boiler for generating steam by utilizing a flue gas discharged from a gas turbine as a heat source comprises an economizer for preheating feedwater by the flue gas, an evaporator for evaporating the preheated feedwater, and a superheater for generating a steam for driving a steam prime mover by heating the evaporated feedwater. The economizer, the evaporator and the superheater are successively arranged in the direction from a downstream side to an upstream side of flue gas passage. The evaporator itself is divided into two sections and an apparatus for removing NO.sub.x is provided in a space between the divided two sections of the evaporator in the flue gas passage to remove NO.sub.x from the flue gas. An NO.sub.x concentration of a flue gas discharged from a combined cycle power plant including the gas turbine can be stably abated at any of full and partial loads.

Abstract: An improved ion thruster (10) for low specific impulse operation in the 1500 sec to 6000 sec range has a multicusp boundary field (48) provided by high strength magnets (30-38) on an iron anode shell (14) which lengthens the paths of electrons from a hollow cathode assembly (20). A downstream anode pole piece in the form of an iron ring (40) supports a ring of magnets (44) to provide a more uniform beam profile. A cylindrical cathode magnet (46) can be moved selectively in an axial direction along a feed tube (22) to produce the desired magnetic field at the cathode tip (24).

Abstract: A flow control valve for a power steering system of the kind having a metering pump is provided with a leaf spring device stressed upon rotation of a hand steering wheel to operate a valve sleeve and the metering pump. The spring device provides a force for returning the valve sleeve to neutral position after a steering operation and comprises curved or arched springs between pressure plates. The convex sides are back-to-back between pressure plates and have curved ends supported on and shaped to slide on the pressure plates with minimum friction as the springs are compressed. The pressure plates are uniquely shaped in the central areas for providing flexibility to compensate for manufacturing inaccuracies.

Abstract: A collection device for energy from water with wave motion has working fluids, a number of pumping units and accumulators interconnected together, and valves to regulate the fluid flow. Each pumping unit has a chamber with an intake port connected to an accumulator, an exhaust port connected to another accumulator, and an outlet to the water. The working fluid in the chamber is in contact with the water, or is partitioned from the water by a flexible membrance or a piston. The pressure from the wave motion of the water pumps the working fluid from one accumulator to another with certain pressure or elevation increase. The working fluid gains suitable pressure or elevation increase through several stages of pumping units.

Abstract: A power plant having a fluid powered flywheel is disclosed. The flywheel comprises internal cylinder spaces which extend radially outwardly from a central region of the flywheel but which curve in a particular circumferential sense about the axis of the flywheel. Helical structures are disposed within the cylinder spaces to define respective helical flow paths through the cylinder spaces. Power fluid is delivered to a central region of the flywheel for entry into the cylinder spaces. Exhaust ports are provided to extend between the outer perimeter of the flywheel and the radially outer end of each cylinder space so that the exhausting fluid is jet discharged. Pressurized fluid is delivered from a reservoir containing a gas-over-liquid power source. An impeller driven by the flywheel collects the fluid discharged from the perimeter of the flywheel and returns it to the reservoir.

Abstract: A brake booster includes a body having a central wall portion on which a, doughnut-shaped reinforcement plate is securely mounted, and bolts mounted on the reinforcement plate for fastening a master cylinder to the central wall portion. The reinforcement plate has an annular ridge extending along an inner peripheral edge thereof and projecting against the reinforcement plate. The master cylinder includes a flange mounted on the body and having an inner peripheral portion held against the central wall portion of the body in axial alignment with the annular ridge, and an outer peripheral portion spaced from the central wall portion by a distance such that the outer peripheral portion of the flange will not be forced into contact with the central wall portion when the master cylinder is actuated for braking action. Therefore, no localized forces are applied by the outer peripheral portion of the flange to the central wall portion of the body.

Abstract: A system for correcting the effect of altitude on an engine with a supercharger. A bypass is provided to bypass an exhaust gas turbine of the supercharger and a waste gate valve is provided in the bypass. An actuator is provided for operating the waste gate valve. The actuator has a supercharging pressure chamber supplied with supercharging air, a standard pressure chamber filled with air at standard pressure, and a diaphragm partitioning both chambers. The diaphragm is operatively connected to the waste gate valve so as to open it when the diaphragm is deflected by an increase of the pressure in the supercharging pressure chamber.

Abstract: A control method and device for the waste gate of a turbocharged internal combustion engine. This exhaust discharge control device entails a waste gate held closed by at least one spring which pushes it back into the closed position against the engine air feed pressure prevailing immediately downstream from the compressor and acting on a control piston for the gate in order to bring about the opening of the gate and to bypass the turbine. The control chamber (20) delimited by at least a part of the surface of the control piston (22) is connected by a conduit (25) and a control valve (27) to a source of fluid under pressure (29, 28a). The control valve (27) is activated by the accelerator pedal (35) of the engine in the area (36) of low engine loads. The invention is applicable to the automatic bypassing of a supercharging turbocompressor's turbine at low engine loads.

Abstract: The present invention relates to gas turbine systems for generating high-temperature process heat. To simplify the primary circuit and to eliminate the necessity of using the same circulation means for the primary and drive circuits in gas turbine systems, a system of this type is designed so that the medium heated in the secondary part of a heat exchanger is divided into a portion of drive gas for operating the drive circuit and a portion of process gas for the actual generation of process heat in the secondary circuit. After the process heat has been given off in a process-heat consumer part, the process gas is then expanded in an expansion turbine and thereafter recycled to the drive circuit. Thereupon, the combined drive gas and process gas, which is compressed in at least one compressor located in the drive circuit, is preheated in a recuperator.

Abstract: A gas turbine engine in which the air compressed by a compressor provided therein is injected into a combustion chamber provided therein through an air injection valve after passing through a first air passageway formed integrally with the main housing and a second air passageway formed integrally with the combustion chamber housing. One end of the first air passageway is formed into a funnel shape, so that the air compressed by the compressor can efficiently enter the first air passageway. Since the air flowing through the air passageway according to the present invention is heated while passing along the combustion chamber, it is possible to enhance the combustion efficiency.

Abstract: Valves for controlling process gas at the cold end of an expansion engine are fluid actuated. The actuating fluid is controlled by a solenoid actuated spool valve positioned at ambient temperature. The fluid is cooled in a thermally regenerative flow path extending between the solenoid actuated valve and the fluid actuated valve.

Abstract: The inner cryopanel of a cryopump includes a substrate having a plurality of holes such that the open areas represent 30% to 70% of the surface area of the substrate. A layer of cryosorbing material is secured to one surface of the substrate. An imperforate panel is juxtaposed to said one surface of said substrate.

Abstract: An arrangement of controls for a vapor compression open cycle industrial process heat pump permits the level of liquid and fluid pressure in a flash tank to be simultaneously and independently monitored and regulated to assure efficient operation of the system and to prevent equipment failure. Liquid level sensing means send a signal to a modulatable valve associated with a liquid discharge pump to maintain the liquid in the flash tank at an optimum level. At the same time, fluid pressure sensing means send a signal to a modulatable inlet throttle valve to regulate fluid pressure in the tank by regulating fluid as required, to maintain tank fluid pressure at the desired level.

Abstract: A refregerated showcase of the type that cold air is circulated across its front opening and along its bottom wall, rear wall and top wall, in which a guide plate having a short vertical length is provided hanging from a middle portion, in the depthwise direction of the showcase, of an ejection port of the cold air along the top edge of the front opening, whereby a rectified flow of an air curtain can be elongated down to a suction port along the lower edge of the front opening to prevent air in an ambient atmosphere from invading the showcase.

Abstract: An improved cooling system for electronic assemblies provides cold bars (10) and cold plates (60) for supporting and conducting heat away from a plurality of electronic assemblies (12, 52) attached thereto. A plurality of refrigerant holes (A-F, 70-77) are drilled through the cold bar or plate. End caps (27, 28, 61, 62) have well-like areas forming refrigerant return passages that cooperate with the cold bar or plate to interconnect individual refrigerant holes or groups of holes to form multiple pass refrigerant paths through the cold bar or plate to external connections for connecting to a refrigeration system. The holes are preferably threaded to improve heat transfer characteristics. The pattern, sizing, and grouping of holes can be varied to adjust the design of a particular cold bar or plate to the heat load of a given application.

Abstract: A ground-installed coolness storage and utilization system wherein a given volume of water-soaked soil is frozen by passing an air-chilled heat-exchange liquid through tubes buried in the soil, and thereafter on demand the heat-exchange liquid is conveyed out of the tubes buried in the frozen soil to cool a warmer medium such as ambient air in a building.

Abstract: The present invention is a self-aided refrigerated filter assembly and method for its use for filtration of liquid petroleum gas (LPG) so that a liquid phase is maintained during the filtration process and that the LPG is sufficiently subcooled to suppress the formation bubbles to prevent the risk of vapor lock or cavitation damages to a pump downflow from the filtration process and/or to provide liquid for metering purpose.

Abstract: A method for low-temperature plasma treatment of a textile product such as a cloth comprising transporting a textile product to be treated through a reaction chamber, in which low-temperature plasma is produced in situ by applying high frequency electric wave to electrodes provided in the chamber uniformly without stay, for subjecting the textile product to low-temperature plasma treatment uniformly, and an apparatus therefor.

Abstract: A locking device for locking a cap upon the filling neck of a tank permits the protective cup-like member of the locking device to be axially offset from the tank cap to enable the locking device to accommodate itself to the restricted compartment available about the tank neck. The locking device comprises a cup-like cylindrical body member and a pair of inwardly extending collar parts, the body member and collar parts being cooperable with a lock for securing the body member and collar parts against movement. The collar parts are independently pivotally secured to the body member at one end thereof with the opposite ends of the collar parts being apertured and movable relative to the other collar part and the body member in the absence of the lock.

Abstract: The invention relates to an antitheft device for trailers and semitrailers comprising a threaded rod which can be screwed in a block integral to a fixed portion of the trailer or semitrailer and having one end thereof idly engaged in a body integral to a linkage leading to the levers which actuate the brakes of an axle of the trailer or semitrailer. By screwing or unscrewing the threaded rod in said block it is possible to achieve the locking or the releasing of brakes. When brakes are in their locking position, acting on a latch control member operable by means of a key it is possible to engage one end of the latch within an annular groove formed in the threaded rod, so that the latter is prevented from moving axially. During this stage the other end of the latch acts on a non-return valve connected to the service brake circuit in order to allow the brake fluid to flow in one direction only.

Abstract: Disclosed is a security device which includes a cylindrical externally threaded member having formed therein a radial first hole and a threaded second hole formed coaxially with the threaded member and intersecting the first hole. A bar is insertable into the first hole to extend radially outwardly therefrom. The bar includes a notch which is alignable with the second hole when the bar is inserted into the first hole. The device includes a sleeve having a first internal portion engageable with the externally threaded member and a second internal portion. The sleeve is engageable with the bar for preventing rotation of the sleeve with respect to the threaded member. The device includes a key operable pick-resistant lock that includes a lock body that is non-rotatably engageable with the second internal portion of the sleeve and a key operable screw that is threadably engageable with the second hole to engage the notch and prevent the bar from being removed from the threaded member.

Abstract: An improved steering lock is disclosed. It is of the type comprising a rotatable lock cylinder, a latch operable in a first position and inoperable in a second position to engage a recess in a steering shaft of an associated motor vehicle, and a rocking lever operable in a first position and inoperable in a second position to maintain the latch in its second position. During rotation of the lock cylinder in one direction, the latch is caused to move from its first position towards its second position. When the latch reaches its second position, a projection on the rocking lever engages a recess in the latch whereby it is maintained in its second position and the steering shaft is maintained in an unlocked condition. The steering lock includes means mounting the rocking lever for rotation in two different planes. The rocking lever is mounted for rotation in a first plane about an axle and, in a second plane, about one of its ends.

Abstract: A device for the unlocking and locking of doors having pneumatic setting members in the individual door-locking mechanisms is provided centrally with a pneumatic pump (19) having a motor (18) of controlled direction of rotation. This motor can be controlled by means of a DC door switch (2). Immediately after a pressure build-up or vacuum build-up a holding-circuit switch (23) closes a holding circuit so that the DC motor (18) which drives the pneumatic pump (19) continues to operate even if it is immediately switched back directly after the making of contact by the door switch (2).Upon an increase in vacuum or pressure, a contact finger (26) of the holding-circuit switch (23) displaces a contact bridge in such a way that it actuates a bistable change-over switch (10) via mechanical transmission members.

Abstract: A safety lock is provided with two plate assemblies, the first to be mounted on the outside of the door leaf and the second on the inside thereof. Each one of these plate assemblies comprises a first plate adapted to be placed on the side of the door leaf and having a first opening for receiving an actuating mechanism, a second opening housing a transmission gear mechanism, and corner holes for passing fasteners which hold the two plate assemblies together. A second plate is on the outer face of the first plate which comprises holes providing bearings for each gear of the transmission mechanisms as well as holes wider than the ends of the fasteners for housing the same therein. A third plate is spot welded on the outer face of the second plate and prevents access to the transmission mechanism. In the outer plate assembly, this third plate covers the ends of the fasteners and has only one hole, shaped in correspondence with the respective key hole opening of the cylinder lock.

Abstract: The compound tool is made from a powder-metallurgically-prepared portion, establishing the wear-resisting zones onto which a carrier body is cast from steel.

Abstract: A forging press for producing flashless forgings from metal billets or pre-forms has a die-head (26) slidably mounted in a press-head (10) whereby it may retract into the press-head if a predetermined pressure on the die-head is reached or exceeded during the forging stroke. The die-head (26) is slidably mounted in a bore (30) containing hydraulic fluid and connected via conduits (38) and pressure relief valves (40) to a hydraulic reservoir (32). A die cavity for the billet or pre-form is defined between relatively movable die halves (16) and (18).

Abstract: Curved metal structures such as cylinders, circumferential parts of cylinders, tubes, and circumferential parts of tubes formed from flat stock have reformed protrusions in limited areas in order more accurately to position mating parts. The flat stock is formed to its cylindrical or tubular shape with known onestroke die-mandrel techniques, and near and at the end of the forming process there also is a concurrent precision reforming of limited sections of the formed stock by localized radial thinning of the material. When precisely-located radial and axial surfaces are desired at an end of the structure, then this is done at an axial end at least by related localized elongation and cold working of material into contact with a die wall. When a precise internal surface is desired, the reforming and cold working can be done at a substantial distance from the end.

Abstract: A straightening apparatus for use in straightening the bent portions of vehicles including a support frame in which the vehicle is positionable; a pusher unit adjustably mounted on the support frame and adapted to engage the bent portion of the vehicle and applying a straightening force thereto in a first direction; and a backup unit adjustably mounted on the support frame and adapted to engage the vehicle in the vicinity of and in opposition to the pusher unit and apply backup forces to the vehicle oriented generally parallel to the straightening force and in a second direction opposite to the first direction so that the bent portion of the vehicle can be straightened back to its original shape without deformation of the unbent portions of the vehicle.

Abstract: A hand operated bending tool for bending convoluted tubes, pipes, and other tubular material, with the tool providing a tool handle socket and a flexible tube gripping band that, upon initial movement of the tool, will grip and secure the free end of the tube to the bending shoe of the tool.

Abstract: A reference block for ultrasonic examination, said block having an ultrasonic absorber secured to its back surface; and a method for ultrasonic examination using these blocks.

Abstract: In an apparatus for testing lubricating or material properties, two clamping assemblies are pressed together. Each clamping assembly has a clamping surface facing the clamping surface on the other assembly. The first clamping surface has two annular roller paths with the axes of the paths spaced apart. The second clamping surface has one annular roller path intersecting the roller paths on the first clamping surface. Four balls roll in the roller path of the second clamping surface with two of the balls rolling in one of the roller paths of the first clamping surface and the other two balls rolling in the other roller path of the first clamping surface. The clamping assembly with the second clamping surface oscillates back and forth relative to the clamping assembly with the first clamping surface. The pulling force developed by the movement of the balls is measured as an indication of the properties of a lubricant filled into the roller paths or of the materials of the balls and the roller paths.

Abstract: A fluid density transducer with a vibrating tube 16 coupled to excitation pick-up transducers 32 utilizes an elliptical tube 16, having a small degree of ellipticity, to compensate for the variation in the natural frequency of vibration, resulting from a variation in the fluid pressure, i.e. a rise in fluid pressure tending to lower the frequency produces a more circular and hence stiffer tube cross-section tending to increase the frequency. A sealed evacuated chamber 36, formed by connecting together cylindrical nodal masses 24 and 26 using a flexible coupling 28, is used to enclose the vibrating tube 16, thus avoiding the risk of contaminating, and thereby also affecting the calibration of, the tube 16. The tube is supported at each end by a spring plate 12 fixed around its outer periphery to a collar 10 and around its inner periphery to an end-plate 25 of the nodal mass 24 or 26.

Abstract: A leak detection method and apparatus is disclosed, the apparatus comprising an enclosing temporary removable casing member which is connectable about a section of piping to be tested. The casing member provides openings which allow the passage of a section of piping to be tested therethrough, with the portion to be tested being sealably housed on the inner portion of the casing. The casing thus provides an inner leak recovery collection space between the casing and the section of the piping to be tested. The casing in the preferred embodiment is comprised of a pair of casing halves which are structurally connected about the section of piping to be tested by means of a bolted connection, for example, with flanged mating surfaces of each casing half registering and abutting to form a sealable connection about the section of the pipe to be tested.

Abstract: A sliding film rheometer for measuring the viscosity of a molten polymer comprising a measuring cell containing a molten polymer, the cell having a rectangular slit through which is passed a rectangular shaped tape at a constant rate and strain gauges connected to the measuring cell for measuring the shear stress and normal stress produced by pulling the rectangular shaped tape through the molten polymer and through the slit from which the viscosity is calculated. The viscosity measurement provides useful data for obtaining optimum extrusion of said molten polymers.

Abstract: An arrangment for measuring the viscosity of a fluid includes a heated, vertical container which receives a vessel filled with the fluid to undergo a viscosity determination. A pair of vertically spaced sensors are mounted in the peripheral wall of the container and are connected with an evaluating mechanism which includes a timer and a computer. The sensors are also connected with a temperature regulating mechanism which regulates the temperature of the fluid by controlling heating of the container. In operation, the fluid is heated on a predetermined temperature. A standard sphere is then permitted to fall through the fluid. When the sphere passes the uppermost sensor, the latter generates an impulse which activates the timer. Similarly, an impulse deactivating the timer is generated when the sphere passes the lowermost sensor.

Abstract: A high temperature and high pressure consistometer comprises a cylindrical pressure vessel having an integral bottom and a cover for said pressure vessel. A nonmagnetic canister extends downwardly from said bottom and is sealed therein. A driven magnet assembly is journaled in said canister. A drive shaft is connected to said driven magnet assembly extending into said vessel. A nonmagnetic canister extends upwardly from the cover and is sealed therein. A driving magnet assembly is journaled in said canister. A shaft connected to said driving magnet assembly extends downwardly into said vessel. A driven magnet assembly is mounted for rotation on the exterior of the downwardly extending canister and a driven magnet assembly is mounted for rotation on the exterior of the upwardly extending canister. A sample cup is connected to the upwardly extending drive shaft and a paddle is connected to the downwardly extending shaft.

Abstract: A flow cell for monitoring accumulations of microscopic material in heat exchange systems and the like, by measuring accretion on the surfaces of a pair of plates exposed to a primary flow, includes a split housing which supports the pair of plates in closely spaced relation with an inlet and an outlet positioned to apply a primary flow between the plates, and further includes a cavity formed in each housing half with the back or opposite sides of the plates exposed to the interior of the cavity and fluid inlets and outlets leading into such cavities providing for the flow of a secondary fluid through the cavities and across the back sides of the plates for the purpose of more accurately simulating the thermal gradient conditions on the plates in a heat exchanger, and for monitoring the rate of accumulation on the plate surfaces.

Abstract: A system for transmitting an EPR (Engine Pressure Ratio) from a gas turbine is provided with a resolver component (30) which modifies the EPR in accordance with variations in the optimum EPR for a particular turbine under particular conditions. The information from an EPR gauge is transmitted by a synchro transmitter, and is received by a differential transmitter (31) associated with the particular engine being monitored. The differential transmitter (31) is adjusted in accordance with pressure (at 33) and temperature (at 56) conditions in order to provide an EPR reading which is compensated in accordance with actual conditions of pressure and temperature. The differential transmitter (31) is also adjusted (at 45) in order to provide an output which is further varied in accordance with a variation in the optimum EPR under standard conditions for the particular turbine associated with the differential transmitter.

Abstract: A gear shifting mechanism includes an actuator for fore-aft movement with a tachometer and a linear displacement transducer to form a velocity and position feedback actuator. The gear shifting mechanism also includes a solenoid and a pivotal mounting to provide movement of the actuator assembly in a second direction, i.e. from first-second to third-fourth gear shift positions. A second pivotal mounting allows the actuator assembly to follow the curvilinear travel of the gear shift level which is facilitated by the ball joint attachment to the gear shift lever. A spring loaded mounting bracket provides force cushioning to the said gear shift lever. The actuator assembly is mounted on a base plate with legs to straddle the vehicle's floor hump and to secure the said base plate by mounting bolts to engage the vehicle's seat belt anchor openings.

Abstract: The functions of the hydraulic valve lifters here discussed are to automatically compensate for dimensional changes that occur in mechanisms such as valve trains found in internal combustion engines. The lifters accomplish this by locking a noncompressible fluid (oil) in a chamber to cause the push rod assembly to become solid enough to overcome the valve spring and the other included forces and to open the valve. This invention also provides that an engine may be tested at the location in which it is operated and a lifter mechanism provided with a helical orifice having an appropriate length on a plug assembly.

Abstract: Buoy for measuring wave slopes provided with a mainly circular disc shaped body having a mainly horizontal lower surface and protruding downwardly from said lower surface a central circular protrusion having a smaller diameter than said lower surface and dimensioned such that with a horizontal current the pressure deviation caused by said protrusion generates on said lower surface a tilting moment opposite and at least equal to the tilting moment caused by the protrusion itself.

Abstract: In a device for electrically monitoring the level of a liquid present in a container, a plurality of temperature-dependent resistance probes (n-1, n, n+1) are arranged at different heights in the container, they being adapted to be connected one after the other to a source of constant current (5) under the control of a program control device. For the evaluation of the voltage at one resistance probe (for example n+1) connected at the time to the source of constant current (5), a differentiator (6) is provided as well as a comparator (7), which is arranged behind the former and is and acted on by a threshold voltage and is connected to circuitry for forming a display signal. The circuitry comprises counter (4, 19) which counts the number of resistance probes (n-1, n, n+1) whose voltage differential is above the threshold voltage after connection to the source of constant current (5).

Abstract: A diver's combined gauge console having an integral mount for a knife and sheath. The gauges may include a tank pressure gauge and a depth gauge. The gauges may be slightly tilted toward one another for ease of reading. The depth gauge may be externally adjustable.

Abstract: A large number of equally spaced Hall-sensors form a column. They are mounted in a tube with a closed bottom. Each sensor is a packaged integrated circuit with a Hall-cell connected to a Schmitt Trigger circuit. An annular float being fitted slidably about the tube carries a compound magnet that generates a pattern of spaced apart magnetic field regions each capable of switching an immediately adjacent Hall-sensor. The Hall sensors are energized sequentially and one at one time. By counting the number of Hall-sensors scanned, from the beginning end of the column to the first Hall-sensor that is switched, a rough measure of the liquid level is obtained. The magnetic field regions are spaced apart by a distance that is not equal to the Hall-sensor spacing so that the pattern of Hall sensor output voltages provides a unique vernier measure of the liquid level that is appropriately added to the aforesaid rough measure.