Abstract: An automatic transmission comprising a planetary gear mechanism having a first gear driven from a drive shaft, a second gear engagable with the first gear to transmit speed change output to a driven shaft, and a third gear engagable with the second gear to control the operation thereof. A centrifugally operated clutch operates to directly connect the first gear and second gear when the rotational speed of the driven shaft exceeds a predetermined value, and a ratchet type one-way clutch is disposed between the third gear and a fixed construction member to permit rotation of the third gear in the same direction as that of said drive shaft but prevent rotation in the reverse direction.

Abstract: An engine cooling system for a small motorcycle employing a radiator mounted compactly in the vacant space in front of a water-cooled engine. The radiator and engine are located and protected in the rear body of the motorcycle. The rear body prevents the radiator from being damaged by objects picked up from the roadway. Outlet openings at the rear of the rear body aid in the flow of air through the radiator, passed the engine and from the engine compartment.

Abstract: Motorcycles having front leg shields, step floors and rear bodies. The rear bodies contain engines and water cooling systems therefor. The radiators of such systems are located above or behind the engine with inlet air directed to the radiator and independently to the engine of these motorcycles.

Abstract: In an automatic multispeed transmission having at least two centrifugal clutches arranged on a rotary shaft driven by the output shaft of an engine and adapted to engage at predetermined different rotational speeds and higher of the rotary shaft, each clutch having an input member drivingly engageable with an output member by the opening motion of weights, an engagement prohibiting mechanism is provided, which is manually operatable to prohibit the opening motion of the weights of one of the clutches which is engageable at a predetermined rotational speed higher than that of the lowest engaging speed clutch. Further, a disabling mechanism is provided to release the engagement prohibiting mechanism from its prohibiting action to permit the opening motion of the weights when the centrifugal force of the weights is larger than a predetermined value.

Abstract: Motorcycles of the type having front leg shields, step floors and rear mounted engines have water-cooled engines with radiators mounted at the front leg shield. Tubes connecting the radiator with the water-cooled engine extend below the step floor. In certain of the embodiments, a trunk is illustrated within which the filler cap and the radiator tank are positioned for easy access. The trunk may be mounted above and spaced from the front fender to define a passage for frontal air to be directed to the front mounted radiator.

Abstract: A motorcycle having a water-cooled engine. The cooling system includes a radiator located in a hollow front leg shield of the motorcycle. The radiator may be positioned on one side of the down tube while a radiator tank is located on the other. A damper mechanism is disclosed which allows selected flow of heated air from the radiator to be directed toward the rider for warmth. Alternately, heated air flows from the radiator downwardly from the hollow interior of the front leg shield.

Abstract: A motorcycle having a liquid-cooled engine with a liquid cooling system. The system includes a radiator, a water jacket about the engine and connecting feed and return lines. The radiator is located in the forward part of the motorcycle while the engine is located in the rear. The cooling lines pass beneath a step floor located intermediate a front leg shield and the rear body of the vehicle. A thermostat is positioned to selectively control flow through the return line while a water pump pumps flow to the engine. A bypass line extends from the uppermost portion of the cooling jacket at the engine to the radiator for extraction of air from the system. A pressure controlled radiator cap provides selective communication with a reserve tank.

Abstract: An improved automatic transmission is disclosed which includes a planetary gear mechanism and a wet type centrifugally operated clutch for controlling power transmission from a rotating input member to an output member. The clutch is connected to the input member for integral rotation therewith and disposed in a casing at a location close to the planetary gear mechanism. A drive chain for transmitting power from the output member to a driven member is disposed in the casing at a location close to the planetary gear mechanism on the opposite side of the clutch. One or both of the clutch and the chain is/are immersed in a lubricating oil sealingly contained in the casing so that the lubricating oil is scooped up by means of the clutch or chain in accordance with the rotation of the input member so as to be supplied to the planetary gear mechanism.

Abstract: A light, miniaturized power transmission device of the type wherein the power from a drive shaft is transmitted to a driven shaft via a planetary gear mechanism. The planetary gear mechanism has a ring gear, a sun gear disposed concentrically on the radially inner side of the ring gear, and planetary gears disposed between and engaged with the sun gear and the ring gear. At least the meshing portions of the planetary gears, ring gear and sun gear are resiliently held from opposite side surfaces thereof by a pair of side plates attached to said planetary gear mechanism. The side plates permit free orbital movements of the planetary gears and suppresses the relative axial movements of the ring gear, planetary gears and sun gear. A centrifugally operated friction clutch is disposed between the drive shaft and the planetary gear mechanism so as to control the transmission of power from the drive shaft to the planetary gear mechanism.

Abstract: An automatic transmission including a drive shaft directly connected to a drive source, an output shaft, and a planetary gear mechanism provided between the drive shaft and output shaft and serving to effect automatic speed change in power transmission. The planetary gear mechanism is mounted on the drive shaft with its sun gear fitted thereon. Thus, the length dimension of the drive shaft can be reduced to provide a very compact system. Further, a plurality of clutches are arranged in a radial plane between the drive shaft and the output shaft, thus permitting a further reduction in the size of the system.

Abstract: A power transmission apparatus in which a crank shaft of an internal combustion engine, an input shaft of a speed-change mechanism and an output shaft of the speed-change mechanism are arranged in three parallel rows, the input shaft being provided at an end portion with a torque convertor drivingly coupled to the crank shaft. At least two gears are provided on the input shaft and are in mesh with respective gears rotatably mounted on the output shaft. The output shaft is provided at an intermediate portion between the two gears thereon with a shift member which is connected for common rotation with the output shaft but is slidable thereon in axial direction. Between each end surface of the shift member and a facing surface of the gear on the output shaft there is interposed a dog clutch comprising pins on one surface and pin openings in the other surface.