Abstract: A device for mounting a position detecting sensor for detecting a stroke of a cylinder. It has such an arrangement that a rotary angle of a magnetic sensor (1) is regulated to within .+-.5 degrees by a slit (9) formed in a housing (2) mounted thereon with the magnetic sensor (1) and a rotation-locker (7) mounted on a cover (6), the slit (9) allows the housing (2) and the cover (6) to slide on each other, but does not allow the both members to fall off each other, and the cover (6) and a head (4) are aligned with each other by a knock pin (10). With this arrangement, assembling work and highly accurate positioning can be easily performed.

Abstract: The present invention relates to a hydraulic control valve in a construction machine, wherein a parallel port (20b) and bridge ports (20c) which are provided in a valve body (40) of the hydraulic control valve are formed by machining, cylinder drain ports (20e) are limited to through holes opened on opposite sides of the valve body (40) and caused to join together in a tank port block (39). Accordingly, when the valve body (40) is manufactured by casting, only a main core (19) forming a spool port (13h) need be used, so that the control valve can be made compact in size. Furthermore, portions (20', 21') where a passage of a neutral port of the core has heretofore been formed by jointing the main core (19) to joint cores (20, 21) are formed by machining a manual operation process of jointing can be dispensed with and the working efficiency and casting accuracy are improved.

Abstract: In an engine used for a portable working apparatus such as a brush cutter, there are arranged a drive gear rotated by a starter motor, and a driven gear engaging with the drive gear and connected to a crankshaft through a nonreturn clutch. The driven gear is fixed to the crankshaft until the starter motor starts the engine and released from the crankshaft after the start of the engine and after a rotational speed of the crankshaft exceeds that of the starter motor.

Abstract: A method of processing the surface of a metallic rod, wherein coating films (2, 22 and 32) are applied onto portions other than the shape where grooves are to be formed on the surface of the rod, the surfaces of the rods (1, 21 and 31) which are not coated are dissolved and processed by chemical polishing or etching, whereby patterns of very shallow grooves (6, 24 and 34) are formed on the surface of the rod, so that making of grooves on the surface of a very heavy rod, a long rod and a curved rod, which have been considered difficult by the conventional machining, can be easily and accurately carried out. Furthermore, after the making of the grooves, the surface of a rod (41) is plated in a state (42) of being coated by photoresist films and screens, whereby the grooves and the recessed portions (43) are plated (44), and thereafter, the coating films (42) are removed by buffing (45) and the like and the plated surface is finished, thus effectively plating the grooves and the recessed portions.

Abstract: A seal device for a gear pump, whose gear case (1), rotatably containing a pair of gears (2), (3) meshing with each other therein, is closed by side plates (4) at both sides thereof interposing seals (5) therebetween, wherein the seal (5) is formed of a plurality of annular parts (5.sub.1), (5.sub.2), projections 5a) formed on the annular parts (5.sub.1), (5.sub.2), a connecting part (5c) for connecting the annular parts (5.sub.1), (5.sub.2), and a notch (5d) formed on at least one side of said connecting part (5c). Thanks to a structure as above, even when a tensile force acts on the connecting part during the use of the device, cracks concentratedly develop at the notch (5d) and are prevented from developing at the other parts, whereby oil leakage can be prevented.

Abstract: This choke device is characterized in that a starting pump 49 for supplying the fuel in a fuel tank 25 by suction to a starting nozzle port 41, is driven by a fuel motor 53. Starting of the engine is executed by the use of a starting motor or a recoil starter, by supplying the fuel in the fuel tank 25 to the starting nozzle port 41 through sucking of the fuel with the starting fuel pump 49 which is turned by the fuel motor 53, thereby facilitating the ignition by augmenting the concentration of the mixed gas.

Abstract: In an engine used for a portable working apparatus such as a brush cutter, there are arranged a drive gear rotated by a starter motor, and a driven gear engaging with the drive gear and connected to a crankshaft through a nonreturn clutch. The driven gear is fixed to the crankshaft until the starter motor starts the engine and released from the crankshaft after the start of the engine and after a rotational speed of the crankshaft exceeds that of the starter motor.

Abstract: Disclosed is a fuel supply system for an internal combustion engine having a fuel tank, a combustion chamber defined in an engine cylinder, and an air intake passage communicating with the combustion chamber. The fuel supply system comprises a main fuel passage communicating the fuel tank and the air intake passage, first supply mechanism provided on the main fuel passage for supplying main fuel from the fuel tank to the air intake passage responsive to the cranking of the engine a starting fuel passage defined separate from the main fuel passage and communicating with the air intake passage and the main fuel passage, and second supply mechanism provided on the starting fuel passage for supplying a predetermined amount of starting fuel into the air intake passage, in addition to the supply of main fuel, responsive to the temperature of the engine cylinder upon starting of the engine.

Abstract: This fuel supply is characterized in that a starting pump 49 for supplying the fuel in a fuel tank 25 by suction to a starting nozzle port 41, is driven by a fuel motor 53. Starting of the engine is executed by the use of a starting motor or a recoil starter, by supplying the fuel in the fuel tank 25 to the starting nozzle port 41 through sucking of the fuel with the starting fuel pump 49 which is turned by the fuel motor 53, thereby facilitating the ignition by augmenting the concentration of the mixed gas.