Abstract: An intake port for a 4-cycle engine includes an intake port base integrally formed with a cylinder head, and an intake port forming member that forms an intake port together with the intake port base. The area of the cross section of the intake port orthogonal to a centerline of the intake port is substantially uniform from an open intake side thereof toward a combustion chamber. The angle made by the centerline of the intake port and an intake valve shaft is larger than 90° from a viewpoint of the intake valve. Thereby, the 4-cycle engine can output high power with the intake port shape, as formed with above mentioned configuration, that reduces intake resistance and that uses simple design molds. More specifically, the engine can reliably prevent condensed fuel from remaining in the intake port to avoid incomplete combustion of gas.

Abstract: In an engine-driven handheld vacuum/blower, a first grip is provided as one part of an outer shape of an engine casing in which an engine is mounted, and a second grip is formed on a fuel tank which forms another part of the outer shape of the engine casing. The first grip and the second grip are positioned on the opposite sides of the center axis of the engine. Therefore, since there is no unbalanced load applied on either of both the hands, an operator can easily maintain the posture during operation, and can work with the vacuum/blower under good efficiency.

Abstract: A handheld blower is provided with an end pipe having a blowing opening at a distal end thereof, the end pipe being coupled to the upper half side of an impeller case and extended in a tangential direction of the impeller. The blower further includes a grip grasped by an operator's fingers to support the blower in a suspended manner, a stop switch provided on an extension line of a widthwise center line of the grip, and a thumb rest extending to a side of the grip from near the stop switch for receiving the operator's thumb. Thus, the handheld blower can prevent accidental stop of the blower, which is caused by an inadvertent touch to the stop switch with the thumb, during use, and enables the operator to keep orienting the end pipe to a desired direction while mitigating the load on the thumb on the grip.

Abstract: In an engine-driven handheld vacuum/blower, a first grip is provided as one part of an outer shape of an engine casing in which an engine is mounted, and a second grip is formed on a fuel tank which forms another part of the outer shape of the engine casing. The first grip and the second grip are positioned on the opposite sides of the center axis of the engine. Therefore, since there is no unbalanced load applied on either of both the hands, an operator can easily maintain the posture during operation, and can work with the vacuum/blower under good efficiency.

Abstract: An intake passage device is provided for an internal combustion engine having carburetor communicated with a connecting projection of an intake port of a cylinder of the engine, wherein the diameter of the connecting projection becomes smaller toward the inside of the intake port. A connecting pipe is provided for communicating the carburetor with the intake port. An inner end of the connecting pipe is engaged in the connecting projection. There is formed a plurality of one communication passages formed in the connecting pipe for communicating an inside of the connecting pipe with a space between an inside wall of the connecting projection and an outside wall of the connecting pipe.

Abstract: A lubricating apparatus for small-sized four-cycle engines to be used in portable type bush cutters, knapsack type powered sprayers, etc. In the lubricating apparatus, an oil returning channel is arranged to provide communication between a valve gear room and an oil sump, and an oil inhaling channel is branched from the middle of the oil returning channel so as to provide communication to an opening in an immediate lower portion of a skirt of a piston being at the top dead center. By this means, when a crank room is negatively pressurized, the oil sucked from the valve gear room is taken through the oil inhaling channel being in communication to a point inside a cylinder where the highest negative pressure is generated, and fed into the cylinder. An opening portion of the oil returning channel is provided with a check valve for opening when the engine is upright and closing when the engine inverted or slanted to prevent the backflow of oil from the oil sump to the oil returning channel.

Abstract: A four-cycle engine has a base plate provided on a side of the engine and having an opening communicated with a carburetor. A choke plate is pivotally mounted on the base plate, and a choke lever is pivotally mounted on the base plate. A transmitting means is provided for transmitting the opposite rotation of the choke lever to the choke plate so as to rotate the choke plate.

Abstract: A cam gear is mounted on a camshaft, and an intake cam and an exhaust cam are formed on the cam gear for operating an intake valve and an exhaust valve of a hand starting four-cycle engine. A decompression device is rotatably mounted in the cam gear. A decompression cam of the decompression device is exposed from the exhaust cam. The decompression device has a weight, and a spring is provided for urging the weight to the cam shaft. Elastic force of the spring is set so that the weight is urged toward the camshaft in hand starting operation of the engine and moved apart from the camshaft by centrifugal force, thereby projecting the decompression cam in the compression stroke of the engine as to open the corresponding valve.

Abstract: A cultivator has a blade secured to a frame. The blade is downwardly projected from the frame and has an edge at the forward side thereof. An air injector is provided at a lower portion of the blade. A swing arm is provided to move in accordance with the depth of the injector in the soil. A switch produces a signal when the swing arm moves to a predetermined position at which the injector is positioned at a sufficient depth for aerating the soil. In response to the signal, a valve is opened to supply the compressed air to the injector.

Abstract: A starting motor is securely mounted in a holder rotatably mounted on a shaft, a pinion is secured to an output shaft of a starting motor in the holder. The holder is arranged to be rotated by an operator through a start lever from a home position to a starting position so as to engage the pinion with a ring gear securely mounted on a crankshaft. A pair of contacts are provided on the holder, and a contact is provided on the start lever so as to engage with the former contacts. The holder and the start lever are arranged to engage the latter contact with the former contacts when the holder is at the starting position and the start lever is returned to the home position to close an engine starting circuit, so that the starting motor is driven to start the engine.

Abstract: A cultivator has a blade secured to a frame. The blade is downwardly projected from the frame and has an edge at the forward side thereof. An air injector is provided at a lower portion of the blade. The frame is supported with the blade and the injector above the ground by a pair of supporting wheels and a stand which are changeable to a criss-crossed stored position to permit the cultivator to be moved downwardly to its operative position.

Abstract: A frame having a wheel for supporting the frame at a predetermined height has a blade which is downwardly projected from the frame and has an edge at the forward side thereof. An injector is provided at a lower portion of the blade. The frame is moved by a tractor, cutting the soil. Compressed air is injected from the injector into the soil for loosening the soil. Orifices for air injection are located at a narrowed neck of the injector for protection from soil clogging and escape of compressed air.

Abstract: A cultivator has a blade downwardly projected from a frame, an injector provided at a lower portion of the blade, a compressor mounted on the frame and an air tank for storing air compressed by the compressor. An unloading valve provided in a hydraulic circuit for supplying compressed air in the air tank to the injector. The unloading valve is arranged to be opened when the pressure in the air tank is higher than a predetermined value. A master valve is provided in the circuit means, for passing the compressed air to the injector. A mechanical valve is provided to be opened when the depth of the injector reaches a predetermined value, so that the compressed air is supplied to the master valve to open it, whereby air is injected from the injector when the pressure in the air tank is higher than the predetermined value at the predetermined position of the injector.