Abstract: A hydraulic transmission system comprising a housing having at least an oil tank containing oil, an oil pump mounted in the housing and having an inlet port and an outlet port, an oil motor mounted in the housing and having an inlet port and an outlet port, a high-pressure oil passage defined in the housing and interconnecting the outlet port of the oil pump and the inlet port of the oil motor, a low-pressure oil passage defined in the housing and interconnecting the outlet port of the oil motor and the inlet port of the oil pump, an oil supply passage defined in the housing and interconnecting the low-pressure oil passage and the oil tank, for supplying oil pumped from the oil tank by the oil pump for circulation between the oil pump and the oil motor through the high-pressure oil passage and the low-pressure oil passage, and a return oil passage defined in the housing and connecting at least a portion of the low-pressure oil passage to the oil tank, for removing air trapped in the oil circulating between th

Abstract: In a hydraulic system loaded on a working vehicle, an oil pump is fixedly secured to a casing block of a transmission system disposed on a vehicle body as separated from an engine, an input shaft of this oil pump is drivably coupled to an input shaft of the aforementioned transmission system, and a clutch is interposed between the input shaft and a transmission mechanism of the transmission system. Preferably, a control valve is fixedly secured to the oil pump, and a delivery port of the oil pump is directly coupled to an inlet of the control valve. Furthermore, so improved structures of a hydraulic switching valve adapted to be disposed on an outlet side of the control valve is proposed.

Abstract: An elevating apparatus for a working vehicle includes separate front lifting and rear lifting mechanisms that can be elevated by hydraulic cylinders, a feedback rod arranged between a link arm of one of the lifting mechanisms and a hydraulic pressure control apparatus for controlling the hydraulic cylinders. A change-over lever selects the front lifting mechanism or the rear lifting mechanism, and an elevating lever controls elevation of the lifting mechanisms. When one of the lifting mechanisms is selected and elevated by operation of the change-over lever, the elevating lever is operated normally without causing abutment between an adjuster member attached to the feedback rod that is interactive with the elevating lever, and an interactive member of the elevating lever. A return mechanism between the change-over lever and the elevating lever enables the elevating lever to be returned to the neutral position when selecting one of the front and rear lifting mechanisms.

Abstract: There is disclosed a starting decompression device for a four-cycle engine for forcedly open an exhaust valve to decompress a combustion chamber. The starting decompression device includes an interlocking means operatively connected to the exhaust valve, a decompression cam member opposed to the interlocking means, and a return spring for urging the cam member towards an inoperative position at which the exhaust valve is closed. In the device, the cam member is automatically returned, at a suitable time during cranking, to close the exhaust valve, thereby mitigating the initial load of cranking and positively starting the engine.