Abstract: A contact lens for intraocular observation including a lens body having a contact face to be brought into contact with cornea of an eyeball of a subject, and a lens support having a contact portion to be settled on sclera of the eyeball of the subject, the lens body and the lens support being assembled on each other by means of a slide mechanism so as to be movable relative to each other in the axial direction of lens, wherein the lens body is capable of pressing the cornea of the eyeball of the subject by movement thereof in the axial direction of lens relative to the lens support settled on the sclera of the eyeball of the subject. The contact lens of the present invention is of good operability and adapted to effectively prevent slipping of itself on the cornea of an eyeball.

Abstract: A contact lens for intraocular observation capable of optically recognizing an inner portion of an eyeball by contacting the contact lens on a surface of a cornea of an eye to be inspected through a light ray transmitted through an inner portion of the contact lens comprising: an optical path dividing member provided on an optical path for leading a light ray incident on the inner portion of the contact lens to the eye to be inspected for dividing a portion of the light ray on said optical path; and an index provided at a position approximately optically conjugate with a portion to be observed of the eye to be inspected on a divided optical path divided by the optical path dividing member. The portion to be observed and said index can optically be recognized by at least partially superposing a first image of the index on a second image of the portion to be observed.

Abstract: An apparatus for measuring a refracting power of an optical system which comprises: a beam projecting optical system which projects a predetermined moving luminous flux to an optical system to be inspected; a beam condensing optical system in which a photoelectric conversion element receives a luminous flux transmitted through the optical system to be inspected; and a processing system which obtains the refracting power of the optical system to be inspected, based on an output from the beam condensing optical system; wherein a rotating plate having at least one tooth of a converging shape, which is protruded outwardly from a center of the rotating plate, is disposed in a beam path of the beam projecting system; and a luminous flux, both edges, in a moving direction thereof, of which are inclined to the moving direction with angles being different with each other and correspond to both sides of the tooth, irradiates the optical system to be inspected, by intermittently blocking the beam path by the tooth.

Abstract: A variable venturi-type carburetor comprising a suction piston and a needle. The root portion of the needle is fixed onto the central portion of the tip face of the suction piston. An annular groove is formed on the tip face of the suction piston around the root portion of the needle. A narrow groove is also formed on the tip face of the suction piston and extends downwardly from the annular groove to the downstream end of the tip face of the suction piston.

Abstract: A variable venturi-type carburetor comprising a main fuel passage, a slow fuel port and a slow fuel passage connecting the main fuel passage to the slow fuel passage. A fuel metering jet is arranged in the slow fuel passage. The slow fuel passage, between the fuel metering jet and the slow fuel port, is connected to the venturi portion of the carburetor via a jet.

Abstract: A variable venturi-type carburetor comprising a suction piston which has a tip face. A raised wall is formed on the inner wall of the intake passage, which faces the tip face of the suction piston. The raised wall has a substantially straight extending tip edge. The inner wall of the intake passage and the tip edge of the raised wall define a D-shaped air inlet mouth. The connecting portions of the inner wall of the intake passage and the tip edge of the raised wall have an arc shape. The upstream end portion of the tip face of the suction piston and the tip edge of the raised wall define an isosceles triangular air inlet opening therebetween when the amount of air fed into the cylinder of the engine is small.

Abstract: A variable venturi-type carburetor comprising a suction piston which has a tip face defining a venturi portion. The tip face has a flat upstream end portion. A raised wall is formed on the inner wall of an intake passage, which faces the tip face of the suction piston. The raised wall has a tip edge having an approximately V-shaped cross-section. The flat upstream end portion of the tip face of the suction piston cooperates with the tip edge of the raised wall for defining an approximately isosceles triangular-shaped air inlet control opening therebetween when the amount of air fed into the cylinder of an engine is small.

Abstract: A variable venturi-type carburetor comprising a vacuum chamber and an atmospheric pressure chamber which are separated by a suction piston. A needle is mounted on the central portion of the tip face of the suction piston. A suction hole, interconnecting the vacuum chamber to a venturi portion of the carburetor, is formed on the tip face of the suction piston at a position located upstream of the needle. The vacuum chamber is open to the atmosphere via a flow rate control valve apparatus when the engine temperature is low. The vacuum chamber is disconnected from the atmosphere by the flow rate control valve apparatus when the engine temperature is high.

Abstract: A variable venturi-type carburetor comprising a hollow cylindrical casing and a suction piston which is movable in the casing. The casing has a support pipe extending along the axis of the suction piston. The suction piston has a piston rod which is inserted into the support pipe. A bearing sleeve, equipped with a plurality of balls, is inserted between the piston rod and the support pipe. The bearing sleeve has a plurality of connecting grooves formed on the outer circumferential wall of the sleeve and extending in the axial direction of the sleeve over the entire length thereof.

Abstract: A variable venturi-type carburetor comprising a fuel passage which is open to an intake passage. An air bleed passage is connected to the fuel passage. The carburetor comprises an air bleed control valve device for controlling the flow area of the air bleed passage. The air bleed control valve device comprises a bore formed therein, a push rod slidably inserted into the bore for controlling the flow area of the air bleed passage, and a wax valve actuating the push rod. A cooling water passage is formed in the air bleed control valve device so as to surround the air bleed passage and the wax valve.

Abstract: A variable venturi-type carburetor comprising a suction piston which has a tip face having an upstream end portion. A raised wall is formed on the inner wall of the intake passage. The upstream end portion of the suction piston cooperates with the tip edge of the raised wall to restrict the flow of air flowing within the intake passage. The upstream end portion of the suction piston has a V-shaped central portion and flat opposed end portions. The tip edge of the raised wall has a flat central portion cooperating with the V-shaped central portion of the suction piston and has opposed end portions cooperating with the flat opposed end portions of the suction piston and projecting towards the intake passage.

Abstract: A variable venturi-type carburetor comprising a suction piston which has a tip face defining a venturi portion. The tip face has a needle-mounting face at the center thereof, and a metering needle is fixed onto the needle-mounting face. The tip face also has a projecting tip face portion located upstream of the needle and projecting from the needle-mounting face towards the venturi portion. A groove, extending along the axis of the intake passage of the carburetor, is formed on the projecting tip face portion. The projecting tip face portion has a V-shaped cross-section which expands from the groove towards the venturi portion.

Abstract: A variable venturi-type carburetor comprising a suction piston which has a tip face defining a venturi portion. The tip face has a projecting tip face portion located upstream of the needle and projecting toward the venturi portion. A groove, extending along the axis of the intake passage of the carburetor, is formed on the projecting tip face portion. The projecting tip face portion has a V-shaped cross-section which expands from the groove toward the venturi portion. A projection, having a V-shaped cross-section, is formed on the inner wall of the intake passage, which faces the tip face of the intake passage, which faces the tip face of the suction piston. The projection enters into the V-shaped cross-section of the projecting tip face portion of the suction piston when the amount of air fed into the cylinder of the engine is small.

Abstract: A variable venturi-type carburetor comprising a suction piston, a fuel passage, and a needle fixed onto the suction piston and extending through the fuel passage. An air bleed passage is connected to the fuel passage. During engine starting, before the engine begins to rotate by its own power, the vacuum chamber of the suction piston is open to the atmosphere and the air bleed passage is shut off. When the engine begins to rotate by its own power, the vacuum chamber of the suction piston is closed from the atmosphere. After this, the air bleed passage is gradually opened. Such control of the closing of the vacuum chamber and the opening of the air bleed passage prevents engine stall by preventing the fuel mixture from becoming excessively lean when the engine first begins to rotate on its own power and then prevents engine misfires by subsequently reducing the air-fuel ratio to a lean mixture.

Abstract: A device for adjusting the degree of opening of the throttle valve of a carburetor comprising a cam pivotally mounted on a pivot. The cam is actuated by a wax valve and rotated in accordance with an increase in the temperature of the cooling water of the engine. The cam has a cam face which is engageable with a lever connected to the throttle valve for retaining the throttle valve at a predetermined fast idling degree during engine warm-up. An auxiliary lever is pivotally mounted on the pivot. The auxiliary lever has an outer circumferential face which is engageable with the lever of the throttle valve for retaining the throttle valve at the predetermined fast idling degree after completion of engine warm-up.

Abstract: A vent changeover device for carburetors comprising two working ends provided on a piston rod of a piston moving in a suction chamber, one of which constitutes a rod end of the piston and the other of which constitutes an angle member joined to an end portion of the piston rod, an inner valve being actuated by the angle member so as to open and close an inner vent, an outer valve being actuated by the rod end so as to open and close an outer vent and disposed so as to face in a direction opposite to the direction in which the inner valve faces, and springs biasing the inner and outer valves, respectively, in vent-closing directions, the vents communicating with the fuel bowl via the respective valves, the inner and outer valves being adapted to be actuated in accordance with the movement of the piston rod such that when one of the valves is opened, the other is closed, the inner vent being opened only when the engine is rotated, and the outer vent being opened only when the engine is stopped.

Abstract: A feedback type variable venturi carburetor in which the negative pressure regulated by the variable venturi at a constant level is supplied to a solenoid valve which is opened and closed at a frequency of 5-30 Hz and whose open-close time ratio is controlled in accordance with the signal from exhaust gas sensor to control the vacuum pressure applied to a diaphragm chamber of an air-bleed flow control means thereby controlling the air-fuel ratio of the mixture at an optimum level. This invention obviates the use of a regulator for regulating the negative pressure from the intake manifold and precludes the drawbacks experienced with conventional carburetors, such as the slow response in the feedback control caused when the main fuel system and the idling system of the conventional carburetor are switched over, and the unstable supply of fuel when the fuel begins to be delivered from the main fuel system.

Abstract: A variable venturi type carburetor having a suction piston movable in response to the intake air flow rate to maintain a substantially constant flow velocity at a venturi portion defined between itself and the opposing wall of the carburetor body, the suction piston being provided at its bottom with a pair of partition plates having exponential, arcuate or tapered end surfaces, in order to suppress self-excited oscillation of the suction piston. The pair of partition plates being opposed by a bridge formed on the wall of the carburetor body to form therebetween a diverging opening. The distance between the pair of partition plates and the bridge is independently adjustable to make it possible to maintain a desired size of gap to avoid the fluctuation of fuel metering characteristics.

Abstract: A floatless variable venturi type carburetor in which the float chamber is substituted by a fuel pressure regulator. The carburetor has, in addition to the ordinary constituents such as variable orifice, fuel metering jet and air bleed, a fuel valve disposed in the fuel passage leading to the fuel metering jet and adapted to be opened and closed in relation to the turning on and off of the engine key switch, and a fuel pressure regulator adapted to regulate the pressure of the fuel introduced to the fuel metering jet through the fuel valve. The fuel pressure regulator has two regulating chambers, one of which being communicated with the inlet side of the fuel valve while the other being in communication with a venturi vacuum pickup port, so that the fuel pressure regulator maintains a constant pressure differential, by the action of a diaphragm separating two regulating chambers, between the fuel pressure at the inlet side of the fuel metering jet and the venturi vacuum.

Abstract: A variable venturi type carburetor incorporating a changeover valve which conducts the fuel vapor in the float chamber either into the internal passage leading to the suction pipe of the carburetor or into the external passage leading to the canister. The changeover valve is actuated via a rod projecting into the intake passage by a suction piston which is displaced according to the amount of air drawn into the engine and which abuttingly contacts the rod. With this invention, an electromagnetic valve employed in the conventional carburetor can be obviated and the structure of the carburetor becomes simple and small.