Abstract: A vehicle having driving wheels both on the left and right sides of the chassis frame thereof. The vehicle has a power unit including an engine and a transmission system for transmitting the power from an output shaft of the engine to the driving wheels independently. The power unit has a casing constructed as a rigid member supporting the driving wheels and rockably connected through a pivot shaft to the chassis frame so as to permit vertical movement of the driving wheels. The vehicle also includes a differential gear having a case connected to the output shaft. The transmission system includes a left and a right input sections extending from a left and a right side gears of the differential gear and output sections through which the input sections are drivingly connected to respective driving wheels. The output sections include V-belt type automatic transmissions.

Abstract: A motorcycle engine having a tensioning mechanism for a cam chain. The mechanism includes a guide on the slack side of the chain which is controlled by two spaced pivotally-mounted links. One of the two links is biased by a spring to tension the cam chain. A sliding rod mechanism prevents facile motion of the links to lessen tension in the cam chain while allowing free tightening. The links are of such proportional extent that the end of the guide nearest the driving sprocket provides the tensioning motion while the end of the guide adjacent the driven sprocket remains tangent thereto.

Abstract: A power transmission casing apparatus in a motorized two-wheeled vehicle which comprises a case main body extending from one lateral side of an internal combustion engine to one lateral side of a rear wheel in rear thereof and supporting rotatably a wheel axle of the rear wheel. The case main body is applied with a cover member for containing therein liquid-tightly a reduction gear means, and is applied with another cover member for containing therein a V-belt means.

Abstract: A power transmission casing apparatus in a motorized two-wheeled vehicle which comprises a case main body extending from one lateral side of an internal combustion engine to one lateral side of a rear wheel in rear thereof and supporting rotatably a wheel axle of the rear wheel. The case main body is applied with a cover member for containing therein liquid-tightly a reduction gear means, and is applied with another cover member for containing therein a V-belt means.

Abstract: A sealing structure of a rotary valve in an internal combustion engine in which a recess is formed either at an opening portion of a rotary valve proper or at an opening portion of a combustion chamber in a housing and in which a seal member slidably fitted in the recess is resiliently pushed against the opposing part by means of a spring member. An annular resilient member is interposed between the lower surface of the seal member and the opposing bottom surface of the recess in such a manner that the two ends of the resilient member are respectively in contact with the surfaces of the seal member and the recess. Thereby, the contact pressure at the ends of the resilient member is increased by utilizing the gas pressure in the combustion chamber. Further, the pushing force of the seal member against the opposing part is increased, so as to enhance sealing efficiency.

Abstract: A lubrication apparatus for an internal combustion engine is provided which has a crank chamber with an oil pan detachably mounted on the lower surface of the crank chamber. An oil pump and an oil filter are coupled together by an oil passage in the crank chamber. A relief valve is provided in the oil passage, the relief valve being opened by an oil pressure above a predetermined value. The oil passage includes an opening directed towards the oil pan and the oil pan includes a rib formed on the upper surface thereof, wherein the relief valve is inserted in the opening and is supported therein by the rib.

Abstract: A rotary valve in an internal combustion engine in which the rotary valve proper is formed so as to be hollow and cylindrical and arranged in such a manner that its inner space forms a portion of an intake passage and a portion of an exhaust passage, which portions are separated from each other. In this manner, the valve proper, exhaust passage, and a housing are effectively cooled, and sealing for the rotary valve proper is made effectively and positively.

Abstract: A power transmission casing apparatus in a motorized two-wheeled vehicle which comprises a case main body extending from one lateral side of an internal combustion engine to one lateral side of a rear wheel in rear thereof and supporting rotatably a wheel axle of the rear wheel. The case main body is applied with a cover member for containing therein liquid-tightly a reduction gear means, and is applied with another cover member for containing therein a V-belt means.

Abstract: A method of bevelling the peripheral edges of port openings on the inner wall of cylinders for two-cycle engines. At least the upper and lower edges of the port opening on the inner wall of a cylinder are shaped, in advance when casting the cylinder, into concavities arcuately recessed in both axial and radial directions of the cylinder. The boundary edges between the recessed concavities and the inner wall of the cylinder are lightly bevelled by pressing or grinding so that an excellent workability, mass-productivity, and great precision can be attained.

Abstract: Microwave heating apparatus employing at least one surface waveguide which is provided in a lower portion of the apparatus below an article to be heated receives microwave output, directly or via a tubular waveguide, from an oscillator means, and acts to concentrate microwave energy in a specific region of the apparatus, whereby heating is rendered more efficient and unevenness of heating in the vertical plane is avoided. For improved evenness of heating in the horizontal plane the surface waveguide may be rotated either by separate drive means or by air supplied to cool the oscillator means, or the article to be heated may be rotated or moved reciprocally while the surface waveguide is moving or is stationary. The improved concentration of microwave energy permits greater economy, and offers a particular advantage for producing highly a baked or hardened outer surface without overheating of other portions of an article to be heated.

Abstract: A device for winding a spiral spring to start an engine of a construction such that a pedal shaft and a driving sprocket which is supported on the pedal shaft are connected each other in a freely rotatable manner through a clutch which is engaged and disengaged in accordance with forward and reverse rotations of the pedal shaft, that a ratchet pawl which permits the forward rotation of the pedal shaft and prevents the reverse rotation thereof is caused to be engaged with the outer peripheral teeth of the driving sprocket, and further that the driving sprocket and a driven sprocket which is provided on a starter shaft to be connected with a spiral spring are interlinked by a power transmission chain so as to cause the spiral spring to be wound around the starter shaft at the time of the forward rotation of the driving sprocket.

Abstract: A power unit for a motor-cycle of a type having a power transmission case which supports at the rear end thereof a rear axle and which is integrally joined together at one end of a crank case of an engine, wherein the power transmission case is constituted by an inner half directly connected to the crank case and an outer half separably connected to the inner half, the rear axle being fitted onto the inner half of the power transmission case, a driving power transmission mechanism is disposed in the inner half to connect the rear axle and a crank shaft of the engine. A pedal shaft having an engine starting pedal connected at one end thereof and an engine starting shaft adjacent to the crank shaft on the same axis is fitted onto the outer half of the power transmission case. A starting power transmission mechanism is disposed in the outer half to connect the crank shaft and the engine starting shaft.

Abstract: An improved engine starting device for a motorcycle of the kick pedal type is provided which is easy to operate, does not require any large force of operation and is thus particularly suitable for an unskilled and powerless person such as a woman or girl to operate. To this end, the device includes a spiral spring which is operatively associated with an engine crankshaft and with a pedal arm so that it can rotate the crankshaft for engine cranking by releasing its spring force or energy previously accumulated by several repetitive swing motions of the pedal arm due to the rider's foot operation. The device also provides improved safety in engine starting operation by preventing the motorcycle from starting to run unintendedly even where the engine is started with the engine throttle valve being opened excessively.

Abstract: There is disclosed a microwave heating apparatus which includes a source of high frequency electromagnetic energy which generates microwaves having a predetermined operating wave length, a heating chamber to accommodate therein a material to be heated, a spatial arrangement to transmit microwaves generated by the source, and a surface wave transmission circuit or line positioned between the chamber and the spatial arrangement. The microwave power from the source is coupled to the spatial arrangement and possibly to the chamber. Heating of a material to be heated takes place as the high frequency electromagnetic waves impinge upon the material and penetrate thereinto.

Abstract: There is disclosed a magnetron power supply means which avoids use of bulky components and which has a frequency converter for drive of a magnetron at a frequency higher than that of a commercial power source. Feedback is supplied to the converter which in response maintains output within a specific range, which may be adjustable, whereby the power supply to the magnetron, and hence the output thereof are regulated.