Abstract: Stretch wrapping apparatus comprising a puckering device and an expandible rectangular frame demountably supported on the puckering device. Belts on the puckering device are provided to feed a length of plastic film tube onto pillars on the expandible frame to form a puckered band as a sub-base supporting the belts is raised relative to the pillars. A drive housed in the puckering device disengagably connected to jacking means on the puckering frame is provided to expand the frame and stretch the band to a size such that the expanded frame and the puckered band thereon can pass freely over the article to be wrapped.

Abstract: Roll opening apparatus for separating the crop conditioning rolls of a mower conditioner is presented. The mower conditioner is of the type wherein a wheel supported main frame has mounted thereto by pivotal linkage a transversely disposed header having a sickle spanning its forward edge, a rotary reel for rearwardly sweeping the crop cuttings across a platform, and an auger at the rear of the platform for delivering the crop cuttings to the nip of a pair of laterally extending upper and lower crop conditioning rolls. The lower conditioning roll is rotatably mounted to the header on a fixed axis. The upper conditioning roll is mounted on lever arms pivoted to the header and biased by tension springs to an operating position adjacent the lower roll. Each lever arm is fitted with a hydraulic cylinder mounted so that extension of its piston causes the upper conditioning roll to open against the force of the tension springs.

Abstract: A mobile agricultural harvester has a crop header connected to the harvester main frame for vertical swinging movement by a pair of pivot collars held against a pair of upright posts by releasable fasteners.

Abstract: An apparatus for use in lawn and garden maintenance, in which a chassis having a pair of axially aligned and independently operable drive wheels carries a central reel mower mounted with the rotational axis of the mower and the drive wheels lying in the same vertical plane. A pair of outer reel mowers may be mounted on the chassis on each side of the path of the central reel mower. A cultivator mounted on a chassis with a pair of axially aligned drive wheels has the frame of the cultivator projecting laterally and aligned with the axis of the drive wheels, the frame of the cultivator being preferably extensible. A lawn trimmer swivelly mountable vertically on a motor driven chassis comprises an articulated arm with a trimming device mounted on the free end of the arm, the arm comprising two pivotally joined parallelogram units and a handle for manipulation of the arm.

Abstract: A harvester for chili peppers and the like including a frame structure supported from a tractor or similar vehicle for movement along one or more rows of plants with the frame including rotatably supported picking units for removing chili pods from the plants and depositing them onto adjacently oriented longitudinally extending conveyors with the picking operation leaving the plants substantially unharmed so that the plants can continue to grow additional pods. The picking units are rotatably driven by a single hydraulic motor communicated with the hydraulic system of the tractor and the picking units can be vertically adjusted by hydraulic rams or the like connected with the hydraulic system of the tractor to enable the operator to control operation of the harvester.

Abstract: A coal gasification composite power generating plant has a coal gasification plant and a composite power generating plant. The coal gasification plant has a low-pressure steam generator for recovering heat from the furnace wall of a pressurized fluidized bed type coal gasification furnace, and a high-pressure steam generator disposed at the outlet of the gasification furnace and adapted to recover heat from the unrefined gas coming from the gasification furnace. The composite power generating plant includes a gas turbine which uses the gas generated in the gasification plant as the fuel gas, a boiler for recovering heat from the exhaust gas of the gas turbine, and high-pressure and low-pressure steam turbines which operate with the steam generated by the boiler.

Abstract: An anti-icing system for a rotating blunt nose bullet of a gas turbine engine uses a rotating thermosyphon effect to create a circulation within a chamber connected for rotation with the nose bullet which draws hot air from a downstream region of the engine forwards to impinge on the nose bullet over a small region close to the engine axis. This avoids complications with separate hot air supplies or electrical heaters. As shown in FIGS. 3 and 4 of the drawings, in one embodiment of the invention the chamber consists simply of a tube closed off by the nose bullet and in combination with an engine main shaft which extends to the turbine region of the engine to draw hot gas from this region. Alternatively, the chamber may extend only to the downstream end of the first compressor.

Abstract: An air/oil heat exchanger is relatively interconnected to the compressor discharge air or fan discharge air of a fan-jet engine to minimize the size of the heat exchanger core so as to be able to locate the heat exchanger within the intermediate case between struts. The plumbing may be combined with the surge bleed system to simplify the systems and reduce weight and cost.

Abstract: The control device comprises at least one control ring to which one end of n elbow lever is articulated. The vane pivot of alternating vanes is fixed at the intersection of the arms of the elbow levers. The other end of each elbow lever is connected by a rod to the end of a straight lever, the other end of which is fixed to the pivot of an adjacent vane. The circumferential movement of the ring causes the pivots of the adjacent vanes to pivot in opposite directions. Two other embodiments have two rings.

Abstract: A pumping apparatus includes a reversible variable displacement drive pump having two ports and a lifting apparatus connected to one of the ports. The lifting apparatus is designed to fit on the well-head of an oil well and attach to the polish rod of the well to operate a down-hole pump. A fluid accumulator containing a precharge is connected to the second port of the drive pump. A pump-off control system automatically adjusts the pumping rate of the lifting apparatus to the individual rate of formation flow of a particular well.

Abstract: A thermo-siphon type generator apparatus making use of a gravity-type heat pipe in which a working medium is cyclically evaporated and condensed. The apparatus has a closed vessel filled with the working fluid and defining a lower evaporating section, an upper condensing section and a heat-insulated section between the evaporating and condensing sections. A turbine connected to a generator is mounted in or on the closed vessel. A first passage is provided for introducing the vapor of the working fluid generated in the evaporating section to the turbine, while a second passage is adapted for introducing the vapor from the turbine to the condensing section.

Abstract: In order to stop the continuous stream of liquid nitrogen supplied through the outlet conduit 4 of the device 2 for regulating the pressure, this conduit is provided with a stop electrovalve 5A combined with a degassing device 27 so that the flow of plain liquid in normal operation is not disturbed. Application to the pressurization of preserving boxes or cans by vaporization of liquid nitrogen.

Abstract: Time dependent fluctuations in a low pressure drop heat exchanger can be prevented by incorporating an improvement into the heat exchanger and practicing a method relating to the pressure drop across the heat exchanger tubes. The improvement comprises an orifice at or near the inlet of the tube wherein the flow flowing into the tube at a liquid inflow rate enters the tube in the liquid state and is then converted while in the tube into a gaseous state at some point downstream from the orifice. The tube is characterized at a given pressure. The fluid, now in a gaseous state, exits the tube at a gas outflow rate. The orifice is disposed at the input of the tube and is sized to provide an inlet pressure drop across the orifice to the liquid which enters the tube at a magnitude equal to a fractional portion of the low pressure drop across the tube itself.

Abstract: The invention is a UF.sub.6 -recovery process of the kind in which a stream of substantially pure gaseous UF.sub.6 is directed through an externally chilled desublimer to convert the UF.sub.6 directly to an annular solid ring adhering to the interior wall of the desublimer. After accumulation of a desired amount of solid UF.sub.6, the desublimer is heated to liquefy the solid. Subsequently, the liquid is recovered from the desublimer. It has been found that during the heating operation the desublimer is subjected to excessive mechanical stresses. In addition, it has been found that the incorporation of a very small percentage of relatively noncondensable, nonreactive gas (e.g., nitrogen) in the UF.sub.6 input to the desublimer effects significant decreases in the stresses generated during the subsequent melting operation.

Abstract: A process as disclosed forming a non-agueous, free-flowing composition. The process involves treating a finely divided inorganic or organic material with liquid carbon dioxide to form a slurry. The treated material is separated from the slurry and shows suprising free-flowing, nonagglomerated behavior.

Abstract: In a cryopump, condensation of gases such as argon, oxygen and nitrogen on surfaces other than the second stage array 38, 40 is avoided to prevent cross over hang up and pressure instability. To prevent condensation of argon, oxygen and nitrogen on the frontal cryopumping array 46, that array is held to a temperature of at least 50.degree. K. A heat load to the first stage increases as the temperature of the first stage drops. That heat load is provided by a high emissivity radiation shield 44 or by a thermal switch 56, 58. Condensation of argon and other gases on the second stage refrigerator cylinder 32 is avoided by a close fitting sleeve 52 positioned over the refrigerator cylinder 32 in thermal contact with the second stage heat sink 30 but out of thermal contact with the cylinder 32.

Abstract: The leads for an infrared detector unit are arranged to pass through bores in a cooled detector housing with intimate contact with the cooled detector housing for precooling the leads extending from the detector elements to the respective preamp leads.

Abstract: Ice lollies are frozen in two-parted moulds which are inserted in rows of freezing pockets in an ice lolly freezing machine. The moulds are thawed loose from the freezing pockets in which freezing has been carried out, are lifted out of the freezing pockets, separated for releasing the frozen ice lollies, assembled and inserted again into a row of freezing pockets. Before the moulds are lifted, a moderate heating of the freezing pockets is carried out sufficient for thawing loose the moulds with respect to the pockets. Then the moulds are lifted and moved to a position outside the area of such freezing pockets of such freezing machine. At the position the moulds are heated for thawing loose the ice lollies. Then the moulds are separated and the ice lollies removed while the moulds are positioned outside the area of the freezing pockets. Now the moulds are moved back to the area of the freezing pockets and are inserted into an empty row of freezing pockets.

Abstract: The optimum charge in the heating and cooling modes is achieved in a reversible heat pump system by providing a receiver in the indoor section which is sized to store an amount of refrigerant equal to the difference in the optimum charge in each mode. The amount of refrigerant in the receiver is varied in response to the ambient temperature whereby the refrigerant charge is optimized over a range of temperatures.

Abstract: An air conditioning system for a vehicle has a compressor adapted to vary its capacity so as to maintain the suction pressure of refrigerant. A door is arranged upstream of the evaporator in an air passage, which can assume a variable opening to vary the refrigerating capacity of the evaporator. The opening of the door is controlled in response to the set position of temperature setting means which sets the discharge air temperature, whereby the refrigerating capacity of the evaporator can be reduced when overcooling takes place, to thereby reduce the work done by the compressor for minimizing a waste of energy.

Abstract: A capacity control system for a refrigeration system including a compressor, a condensor, and an evaporator, all connected in a closed refrigeration circuit is provided. The compressor includes a plurality of adjustable inlet guide vanes, a motor connected to regulate the inlet guide vanes position, and an electrical speed motor connected to drive the compressor. The capacity control system includes a microprocessor responsive to continual measurements of a PRV signal, a compressor head signal and a suction flow signal for calculating a current operating point. The microprocessor determines whether the operating point is sufficiently away from a surge surface. The microprocessor will cause the operating point to move to a new operating point of a lower compressor speed and a more open PRV position if the operating point is sufficiently away from surge.

Abstract: To cool electronic heat producing elements and components which are normally connected to a heat sink, an evaporator containing a circulating coolant is thermally connected to each of the heat producing components. The evaporator absorbs the heat from the heat producing element. The coolant is boiled or evaporated within the evaporator. The pressure on the gas produced by the evaporation is maintained at a constant pressure. This will result in a uniform temperature of the liquid as it is being evaporated. The heat producing components, therefore, will be maintained at substantially a constant temperature. Several heat producing elements may be connected to a single evaporator. For retrofitting existing units, individual evaporators are made to attach to the heat sink between the heat producing component and the heat sink.

Abstract: An absorption refrigeration system utilizing a low temperature desorber and intermediate temperature resorber. The system operates at three temperatures and three pressures to increase the efficiency of the system and is capable of utilizing a lower generator temperature than previously used.

Abstract: A cooled infrared detector post includes a detector post formed of a stack of wafer disks with a detector substrate wafer forming one end of the post and a cooling chamber adjacent to the detector substrate with coolant supply and return passages formed in the series of wafers with a supply passage contained to a supply port with a supply passage forming a plurality of serpentine passages at various planes within the post and a return passage including a plurality of precooling chambers with the wafer stacked in a predetermined arrangement and fused together to form a monolithic post structure.

Abstract: A circular knitting machine for the production of knit goods with combed-in fibers, has a rotating needle cylinder in which needles having hooks for receiving fibers are mounted, at least one carding device having a feed apparatus for feeding a fiber strand, a separating apparatus for separating the fiber strand into a stream of individual fibers, and a combing-in zone through which the needles pass, and wherein the fibers are carried within the fiber stream for the purpose of contactlessly combing-in the fibers into the hooks of the needles. Guides are provided ahead of the combing-in zone for the purpose of dividing the fiber stream into partial fiber streams, thus considerably reducing or varying the percentage of fibers which are bound across several neighboring loops by several neighboring needles.

Abstract: To permit independent adjustment of movement of knock-over bit - jack sinker elements (3) having knock-over or casting-off heads (7), a cam box (22, 23) has an individually adjustable raising and lowering cam track (26, 28), engaging a butt (6) on the sinker element. The shaft (4) of the jack or sinker is formed as a double-arm lever (16, 17) with an intermediate fulcrum or pivot point projection (18), engaging a surface of the knitting machine, for example a cylinder groove, and two individual cam tracks (34, 35) are provided, formed on cam carriers (36, 37), of which, preferably, at least one (36) is adjustable, to provide for rocking movement of the knock-over bit - sinker jack element about the fulcrum or pivot projection independently of sliding longitudinal raising and lowering under control of the customarily provided cam structure (26, 28).

Abstract: Process and apparatus for applying in a continuous and level manner aqueous impregnating liquors to water-wet textile goods to prevent unlevelness of the liquor applied to the goods. This is accomplished by partly or completely exchanging the moisture on the goods by sucking or pressing liquor through the goods and by circulating the liquor to be applied while maintaining its volume and concentration at a constant value. The new technique makes it possible to dispense with the customary intermediate drying stage after the pretreatment.

Abstract: An improved dry cleaning machine of the type utilizing powdered cleaning agents and having a rotating drum. Such machines have a shroud which completely surrounds the rotating drum and the shroud is connected to a collector and to the intake of an air blower. The draperies, furs, or the like are to be cleaned are rotated in the drum with the powdered cleaning agent for a predetermined amount of time after which the air blower is turned on and the cleaning agents are evacuated from the drum and deposited in the collector. The improved machine has a plurality of spring loaded plates over various groups of openings through the side of the drum.

Abstract: An overload security system for a leather staking machine is disclosed. The system employs a disk spring package in order to release the staking plates from their predetermined positions when a certain critical pressure is exceeded. The position of the staking plates is adjustable for different qualities of leather or different intensities of staking.

Abstract: An inexpensive cable locking mechanism adapted for use with a conventional padlock which is comprised of a male handle portion having a pair of apertures extending axially therethrough, a tubular female member adapted for threaded engagement with the male portion and having a pair of apertures in the extended end thereof, and a flexible cable. The cable extends through one of the apertures in the handle, through the tubular female portion and out one of the apertures in the extended end thereof, loops about the object or objects to be secured and extends back through the other aperture in the extended end of the female member, through the tubular portion thereof and out the other aperture in the male handle portion of the lock.

Abstract: A handle device for a door which is formed of an assembly installed in a door panel and has a handle grip connected thereto by a pivot pin. A latch is retractably mounted to the assembly and is interlocked with the handle grip. An actuating lever is pushed by the handle grip to move the latch. A reset lever drives the actuating lever when pushed by a push rod extending inside the door. A lock mounted on the assembly has a cam secured to a rotor, serves to release the engagement between a lock plate which is secured to the assembly and adapted to check the slide of the latch, and the latch. When the push rod turns the reset lever, engagement between the lock plate and the latch is released and the latch slides and is retracted by turning the actuating lever.

Abstract: A cylinder lock which prevents picking is disclosed. The lock comprises an outer shell having a cavity therein, a plug having a hole and a plurality of circumferential apertures extending partially through the plug, with grooves around the openings of the apertures. The plug is snugly disposed in the cavity. Spring biased pins are slidably received in the plug apertures. The cylinder lock also has a shaft member disposed in the cavity with a flange portion extending outwardly from said shaft member. The flange portion has a plurality of apertures with grooves around the openings of the apertures which face the plug. The apertures extend through the flange portion, and are alignable with the apertures of the plug. The shaft member passes through the hole of the plug, and is adapted to be rotated. The flange portion fits snugly in the cavity. Pins are slidably received in the flange portion apertures.

Abstract: A press assembly by which cut metal workpieces of specified length are formed into blanks of desired shape by punches and dies is provided with a rolling mechanism disposed adjacent to and in line with the press assembly. The blanks formed by the press assembly are fed directly to the rolling mechanism to perform the press work and rolling work continuously.

Abstract: A roller mechanism and method for forming helical shaped structures from a feed wire or rod, wherein the feed wire is drawn through a plurality of staggered forming rollers by rotation of the rollers, while the wire is also being rotated about its own axis so as to form the desired helical shaped product. The mechanism includes a support frame and at least four lower fixed position driven rollers and at least five upper idler rollers having adjustable positions relative to the lower rollers rotatably mounted in the frame. The lower rollers usually have a roughened or grooved surface to facilitate drawing the feed wire through the staggered forming rollers. If desired, the feed wire can be pulled off a rotating supply reel by a pair of guiding rollers and then passed through the forming rollers to provide the desired helical shaped product.

Abstract: A portable electric driven conduit bender which accommodates rigid, IMC and thinwall conduit of various sizes in a single setup includes a rotatable, cone-shaped bending shoe, and a roller assembly for supporting conduit during bending. The bending shoe has a pair of arcuate-shaped die portions positioned diametrically opposite one another for shaping rigid and IMC conduit, and thinwall conduit, respectively, and each die portion has a plurality of bending grooves formed therein for accommodating various conduit diameter sizes. The roller assembly includes a roller unit for larger diameter conduit that has a split forming roller and a solid backup roller located side-by-side which cradle the conduit during the bending operation. One of the halves of the split roller is adjustable in its axial direction between a closed position for supporting thinwall conduit and a separated position for supporting rigid conduit.

Abstract: An apparatus for conveying tubular or bar-shaped rolled stock is provided having a collecting device which collects pieces of tube or bars from a cooling bed in closely spaced pockets, a transverse conveying device having the same pocket spacing as the collecting device which picks the collected pieces from the collecting device and transports them to and deposits them on a longitudinal conveyor, by means of which the pieces of rolled stock are fed to a cutting device which has a clamping device also provided with the same pocket spacing as the collecting device and which cuts the stock into portions of predetermined length.

Abstract: Methods and apparatus for initiating extrusion of elongated hollow product, more particularly cylindrical tubular product, by increasing the space between the end of a mandrel and an opposed extrusion die during extrusion start-up and thereafter gradually decreasing the space to the desired width for extrusion of the product to enhance extrusion initiation.

Abstract: A gear is formed in a gear-forming apparatus including a die block formed with an axial bore and a plurality of teeth radially projecting into the bore and having lead-in portions adjacent one axial end of the bore, and an elongated mandrel axially movable into the bore, by placing at least one blank in position outside the die block and adjacent the axial end of the bore, causing the mandrel to extend through the center hole in the blank; forcing the blank into the bore from the axial end of the bore until the blank is moved past the teeth of the die block so that the blank is caused to form gear teeth on its outer peripheral surface by the teeth of the die block; driving at least one of the die block and the mandrel to move with respect to each other so that the gear resulting from the blank is withdrawn together with the mandrel out of the bore in the die block; and removing the gear from the mandrel outside the die block.

Abstract: An apparatus and method for the high-speed production of seamless metal container bodies is disclosed utilizing a reciprocating ram which forces a relatively shallow metal cup through a die assembly to iron the sidewall of said cup to form an elongated ironed container body, the ram is supported and critically-aligned by at least two stationary guide means along its length and a slide blank means rigidly secured to its rearward end, the slide block means having opposed hydrostatic pressure pads to provide constant critical alignment of the rear end of the ram and prevent misalignment of the ram relative to the die assembly to avoid producing container bodies of overly-inconsistent length.

Abstract: A power operated blind-rivet setting tool comprises a hand-piece which carries a rivet pulling plunger and a piston in a cylinder furnished with a trigger operable valve for admission of working fluid to one or other end of the cylinder. A piston rod joined by one end to said piston has its other end operatively connected to the plunger, and a compression spring sleeved on said piston rod is so arranged as to store energy during a non-working stroke of said piston and to release that energy during a working stroke of the piston.

Abstract: An apparatus for repairing and straightening vehicles includes upper and lower tracks supported in vertically spaced relation by a frame, each track including a pair of laterally spaced apart and longitudinally extending side members. A plurality of tower assemblies are supported on the upper and lower tracks for longitudinal movement therealong. A pit is provided in which cross members support rails positioned directly under side bars of a truck vehicle for a tie-down to extend around the rails and to the vehicle side bars. A longitudinally moveable beam is provided between adjacent lower tracks and the pair of rails and is limited against vertical movement by horizontal flanges facing each other on the tracks and pair of rails. A pulley on the moveable beam engages a tension member extending from the tower to the vehicle to provide a downward pull on the vehicle between the track members and the rails. The structure of the tower assembly allows for pulling on the vehicle frame only at a 90.degree.

Abstract: A method and apparatus for forming self tapping threaded fasteners having a cylindrical gripping portion and a tapered end portion with swaging lobes thereon is disclosed. The apparatus includes a pair of flat dies having a flat G-surface formed with thread rolling grooves therein to form the gripping cylindrical portion of the fastener. A rise angle surface having thread forming grooves therein with lobe forming recesses adjacent to the finished end operate to form the tapered point with lobes thereon. The G-surface is wider at the forward end of the die and progressively narrows until a dwell or finished portion is reached adjacent to the finish end of the die. Consequently, the threads along the tapered portion of the blank are not as fully formed as the threads along the cylindrical portion when the blank reaches the finishing end and excess material is available to fill the recesses and produce the lobes.

Abstract: Disclosed is an apparatus for continually monitoring for the presence of suspended or dissolved gas within a viscous material, such as in the material accumulated in the mud reservoir of a mud system used in an oil or gas drilling operation. Pressurized air is injected into the liquid to agitate and dislodge the gas. The dislodged gas is captured within a sealed chamber upon emerging from the liquid. A sample of the gas is continuously vented from the chamber through an outlet tube under the influence of the pressurized air. A gas sensor is mounted with the outlet tube so as to continually and accurately detect the presence of the gas within the liquid.

Abstract: A vibration densitometer including a synchronous detector, a threshold detector, an integrator, an electromagnetic bridge driver, a piezoelectric crystal pick-off, a voltage controlled oscillator (VCO), a phase detector responsive to the crystal output and that of the VCO to control the VCO frequency and/or phase to provide an output signal of a frequency to energize the driver.

Abstract: Apparatus and methods for durability (fatigue) testing of prosthetic heart valves or other check valves. The apparatus is circular in plan and includes a test fixture in which the valves are circularly arranged, located with communicating passages, such passages communicating with bellows closed at one end. The bellows are carried by a swash plate journalled to a motor by a coupling providing an adjustable tilt axis. The tilt axis determines the amplitude of the motion or flow of the fluid, as the bellows alternately expand and contract. A central bypass chamber includes orifices which are selectively varied in effective cross section to control an amount of the test fluid which bypasses the test samples, thereby determining fluid pressure differential across the sample valves. Fluid in the apparatus can be heated by an electric heater to temperatures similar to human blood, a temperature probe monitoring the temperature for its control.

Abstract: The output signal of an effluent detector, disposed, for example, downstream of a liquid phase chromotography column, is digitalized and then compared to a LEVEL signal, fixed in relation to the base line of the detected signal, plus a deviation value (LO). A slope threshold is defined. As long as the slope of the detected signal is below the threshold, the pilot signal follows the detected signal. When the slope of the detected signal is higher than the threshold, a peak has occurred, and the value of the pilot signal locked, at least during a pre-established time. Thereafter the pilot signal resumes its evolution substantially parallel with the base line. This enables an outstanding detection of the useful peaks in the analysis of effluents.

Abstract: The dynamic axis of a sphere, e.g. golf ball, is located by spinning the sphere at high speed while it is supported on a low friction-bearing surface, thus allowing the desired stable axis to align itself with the spin axis. Markings indicative of the location of the stable axis are applied to the sphere. The spinning operation also indicates the degree of existing eccentricities in the sphere.

Abstract: Capacitative device for measuring the moisture content of granular or powder materials, particularly materials in motion on a conveyor belt or in a pipe comprising a capacitative probe provided with at least two electrodes separated by an insulating zone and in contact with the material being examined, a support frame for the capacitative probe, and high frequency oscillator circuit associated with the electrodes in order to supply an alternating voltage of a frequency variable with the moisture content. The probe, which has a cylindrical body may be rotated by a motor and comprises cleaning scrapers mounted on the frame which cooperate with the body of the probe when the latter is rotating.

Abstract: A system for diagnosing operations of sensing systems of an internal combustion engine. The system comprises a first diagnosing circuit for diagnosing operation of an important system, such as a coolant temperature sensor, the first diagnosing circuit including a comparator for comparing an input from the sensing system with a reference range and for producing an output when the input is out of the range. A display is provided responsive to the output of the first diagnosing circuit indicating trouble in the sensing system, and a second diagnosing circuit is provided for diagnosing operation of a minor sensing system and for producing an output when the input from the sensing system is abnormal. A gate is provided for electrically connecting the output of the second diagnosing circuit with the display. A manually operated control circuit is provided for operating the gate so as to display the result of the diagnosing of the second diagnosing circuit.

Abstract: A system for diagnosing an internal combustion engine having an air-flow meter. The air-flow meter comprises a voltage divider including a variable resistor. A wiper of the variable resistor is operatively connected to a flap in an intake passage so as to produce an output voltage, responsive to the volume of the intake air. A computer is provided for computing the volume of the intake air from the output voltage and a fixed voltage at one end of the variable resistor. A smoothing capacitor is provided for filtering the output voltage and a resistor is connected in parallel to the capacitor for discharging thereof and a diagnosing circuit is provided to respond to the output voltage for producing a diagnosis signal when the output voltage decreases to a predetermined level.