Abstract: A fuel metering arrangement in devices for pneumatically assisted direct fuel injection into an internal combustion engine cylinder head (12) provided with a chamber (19) housing a connecting rod (23) for operating a compression piston (24) slidingly guided within a jacket (25) provided with one or more transfer conduits (26) connecting said internal chamber (19) to a variable-dimension space (27) positioned downstream of the piston (24) and upstream of a valve (28) providing access to a combustion chamber (29), fuel feed means (31, 33, 35) being connected to said variable-dimension space (27). In this manner a very rapid transient is achieved during acceleration.

Abstract: A valve arrangement in an internal combustion engine, into which engine the air-fuel mixture is directly injected by relative pumping elements from a pressure chamber towards at least one cylinder provided with a valve aperture with its relative valve located within a valve body provided with at least one communication channel, between the valve and the valve aperture there being positioned an elastic element which when at rest maintains the valve in its closed position, the valve being inserted into said valve body by way of interposed elements, lockable in their selected position, for adjusting both the preload and its travel.

Abstract: A mixture preparation device for double-feed engines having a body (11) in which two ducts are provided, namely a first duct (12) for air feed to the crankcase and a second duct (13) connected to an injection device. Throttle elements (10, 35) are provided for the two ducts (12, 13). In the second duct (13) connected to the injection device there is provided an air-fuel mixture emission unit (29-34) adjustable in its degree of opening, the opening being controlled by transmission elements (49, 50) operationally connected to a shaft (36, 43) carrying one of the throttle elements (35) positioned within the first duct (12) for air feed.

Abstract: A compact cylinder head arrangement (11) for internal combustion engines, in particular with two cylinders, comprising at least one pair of cylinders provided with a valve aperture (53) and relative valve (56), there being associated with each cylinder a chamber (14, 15) which at one end is connected to the valve (56) and at the other end is connected to means for feeding a fuel mixture, within each chamber (14, 15) there being provided a piston (17, 18) for injecting a mixture generated within the chamber (14, 15) into the respective cylinder, the pistons (17, 18) being moved by a connecting rod (23) driven by a positive transmission (44, 47) operated by a drive shaft, each piston connecting rod (23) being rotatably pivoted on a shaft element (24, 25, 26) rotating within a bush (31) retained in the cylinder head (11) and rigidly connected to the positive transmission, the shaft element and the bush being provided with fuel mixture feed ducts (33, 34, 35) which are alternately alignable during the rotation of

Abstract: An auxiliary carburetion device in direct fuel injection engines, to be positioned in correspondence with a main duct (12) feeding air to the engine crankcase (10), a throttling member (38) being located in the main duct (12). The device includes a block (13) containing at least one selective regulating element (15, 25) positioned in a connection duct (19, 20; 30) which is connected at one end to a vessel (14; 45, 51) containing a constant predeterminable amount of fuel and to a mixing air duct (23, 32), and at the other end to the main duct (12) feeding the crankcase (10).

Abstract: A cylinder head for internal combustion engines, with a device for the pneumatically assisted direct injection of fuel into at least one cylinder provided with at least one spark plug and a valve aperture with its relative valve, fuel feed means being provided, the valve being connected to a chamber into which said feed means cause the fuel to flow. The chamber is connected to a feed duct directly associated with an air pipe and an oil pipe, a piston acting within the chamber in order, during its compression stroke, to inject the air-fuel mixture generated in the chamber into at least one cylinder via the valve aperture, the piston being operated mechanically by a positive transmission driven by the crankshaft.

Abstract: An apparatus is provided for regulating the inflow of fuel into an intake duct (19) of a controlled-ignition internal combustion engine through the utilization of a fuel injection valve (11) having an outlet (21) opening into the intake duct (19) downstream of a multiple position speed regulator valve (30). Conventional control mechanisms (29, 40) energize the fuel injection valve (11) as a function of the operating parameters of an associated engine. A fuel container (13) has an outlet connected by a pipe (12) to an inlet of the fuel injection valve (11), and a float valve mechanism (17) maintains a substantial uniform level of fuel (14) in the fuel container (13) which corresponds to the position of the fuel injection valve outlet (21) whereby the amount of fuel introduced into the intake duct (19) is proportional to the velocity of the air flowing therethrough and substantially absent pressurization from the fuel (14) within the fuel container (13).

Abstract: In order to provide an automatic transmission for vehicles, having a wide range of transmission ratio, a first transmission unit is provided, with a transmission ratio variable with continuity, connected on its inlet side with a driving shaft, and at least a second transmission unit and a third transmission unit are provided, each with a fixed transmsision ratio, which is different from each other, with each of them being connected, on its inlet side, with said first transmission unit, and on its outlet side, with a driven shaft of the vehicle, which they supply with motion, alternatively to each other; the second transmission unit and the third transmission unit are connected with the first transmission unit by means of two respective automatic couplings, which engage at different actuation speeds.

Abstract: A braking system for two-wheelers is provided with a normal-duty actuation member which acts on both a front braking assembly and a rear braking assembly, and with an emergency actuation member which acts on one only of said braking assemblies; means are provided for balancing the actuation force applied by the normal-duty actuation member and the actuation force applied by the emergency actuation member on the common braking assembly, which enable the greater of the two braking actions to be applied as the braking action, for the purpose of preventing the jamming, and hence the skidding of the vehicle wheel on which such common braking assembly acts.

Abstract: In a two-stroke internal combustion engine, with fuel injection and controlled ignition, a valve is provided, which allows or prevents the inflow of fuel into the combustion chamber; such a valve is driven by an electromagnet controlled by a control unit as a function of the engine operating parameter.