More specifically, the present invention relates to a springless-valve engine mechanism having combustion cylinders with valves positioned externally (without occupying any of the interior space of the cylinder), said valves being driven in order to seal the cylinders springlessly, by means of direct engine power transmission. The springless-valve engine mechanism of the present invention significantly improves the efficiency, momentum and horse-power level of the engine, relative to conventional spring-valve engines.

Background of the invention: The spring valve mechanism commonly used in internal combustion engines is comprised of an inlet valve and an exhaust valve, said valves being driven and retained repeatedly in order to seal the cylinder by means of spring power. The valves are opened during the respective cycles of fuel-air mixture suction and gas exhaust, by means of the engine power that is transmitted to the valves through power transmission means including a timing chain which revolves cams arranged on a camshaft in appropriate positions and respective angular orientations. Each valve is being repeatedly driven open by means of direct engine power countering the power of the spring, then driven close (for sealing the cylinder) through the appropriate temporary angular orientation of the cam by which the direct engine power is released from the valve, thus enabling the spring power to retract the valve closed.

It can be clearly understood from the conventional mechanism herebefore described that the valves have a response time dependant on agility and efficiency of the springs used. As it will be further explained, the dependence between the operation of the valves and the response time of the springs impairs the engine efficiency. In order to clarify this matter, we will refer to the critical moments at which the influence of the spring qualities become relevant. As mentioned above, the valves are driven to their"open"mode by means of direct transmission of engine power.

Therefore, by performing careful adjustments, accurate timing of valve opening events can be achieved. The problem arises with the closing events, at which time the valves are closed under the control of their respective retracting springs. In effect, as the engine speed increases, the significance of the spring response time increases, relative to the shortened duration of engine cycle. Thus, as the engine speed increases, the spring-dependant valves work in a manner that becomes increasingly independent on the timing-chain driven camshaft-crankshaft mechanism, and the valves are thus closed more and more imprecisely.

It is utmost essential for optimal engine operation that when the fuel-air mixture is supplied, there be an absolute synchronization between the repeated movements of the valves and the rotation of the crankshaft and its timing chain. In other words, synchronization between the spring-dependant valves and the rest of the interacting parts deteriorates in proportion to the spring's inability to maintain an efficient reaction time.

At the end of the engine intake cycle, when the piston is in its fully descended position at the bottom center point of the crankshaft, the fuel-air inlet has to change immediately from its intake"open"mode to the"close"mode, in order to establish a successful compression cycle.

The greater delay time for this change to happen (due to lack of springs maintaining an efficient reaction time), the less efficient the compression cycle that is established. This is because as the relative significance of the closing delay time increases, a greater part of the compression cycle is performed with an unsealed cylinder chamber.

A similar problem occurs at the end of the engine exhaust cycle, when the piston is in its full advanced position within the cylinder chamber, at the top central point of the crankshaft, and the exhaust outlet has to change immediately from its exhaust"open"mode to the"close"mode, in order to establish a successful intake cycle. As the relative significance of the closing delay time increases, a greater part of the intake cycle is performed with the cylinder chamber opened to the exhaust piping, which negatively effects the suction of the fuel-air mixture.

Various attempts have been made to improve the performance of the valve response time and the camshaft-crankshaft mechanism. To date, none of these modifications have been able to solve the synchronization problems between the two inevitably incoherent parts, which will be the first aim of the present invention.

A further aim of the present invention is to better facilitate the valve mechanism, thus simplifying the engine maintenance tasks, decreasing the wear of valves and associate parts, and reducing the total dimensions of the engine.

Summary of the invention: The present invention relates to a springless-valve engine mechanism for fuel engines, comprising a plurality of combustion cylinders and respective pistons, wherein said pistons are connected in a conventional manner to a crankshaft, and each cylinder has a fuel-air mixture inlet and an gas exhaust outlet. The mechanism is characterized in that at least one of said inlets and outlets has an outwardly-oriented sealing lip that matches with an outwardly located springless valve, said valve being pressed repeatedly into a sealing position in order to seal the respective fuel-air inlet or gas exhaust outlet by means of a revolving cam driven by the crankshaft rotation that is transmitted through respective power transmission means.

According to one embodiment of the springless-valve engine mechanism according to the present invention, the gas exhaust outlet has an outwardly oriented sealing lip that matches with an outwardly located springless valve, wherein said valve is pressed repeatedly into a sealing position in order to seal the gas exhaust outlet by means of a revolving cam driven by the crankshaft rotation transmitted through respective power transmission means, and wherein said cam is shaped in a manner to allow the valve to be drawn-out automatically from said sealing position by means of the exhaust gas pressure during an exhaust cycle of the respective cylinder.

According to another embodiment of the springless-valve engine mechanism according to the present invention, the fuel-air mixture inlet has an outwardly oriented sealing lip that matches with an outwardly located springless valve, wherein said valve is pressed repeatedly into a sealing position in order to seal the fuel-air mixture inlet, by means of a revolving cam driven by the crankshaft rotation transmitted through respective power transmission means, and wherein said valve is drawn-out repeatedly from said sealing position in order to open the fuel-air mixture inlet during a suction cycle of the respective cylinder, by means of a secondary-cam integrally connected to the said revolving cam and cooperating with means for the drawing-out of said valve from said sealing position.

According to the preferred embodiment of the present invention, both inlet and exhaust valves of all the engine cylinders use the springless-valve engine mechanism.

Preferably, the springless valve according to the present invention has a cylindrical contour. Preferably, the cylindrically contoured valve is movably located between the sealing position and the drawn-out position within a cylindrical track ending near said sealing lip. According to various embodiments of the cylindrically contoured valve, the valve's circular basis is adapted for sealing the respective fuel-air mixture inlet or gas exhaust outlet, wherein the cylindrical wall of the same cylindrically contoured valve is adapted to firmly contact a ring-shaped sealing lip located near the end of said cylindrical track facing the free atmosphere, to provide a seal between the free atmosphere and the fuel-air mixture piping or the exhaust piping ending near said inlet and outlet, respectively.

According to various preferred embodiments of the present invention, the springless valve is a hollow body.

According to the preferred embodiment of the present invention, the means for drawing-out the inlet-valve from the sealing position is comprised of a pivoting rocker hinged to a stationary portion of the engine and having an arm partially penetrating a recess or groove formed within the valve body. This allows for the drawing-out of the valve from the sealing position during the engine suction cycles when the above mentioned cooperating secondary-cam pivots the corresponding rocker.

Preferably, the inlet cam is comprised of two similar parts connected in parallel to each other, and the secondary cam is connected in between said two cam parts.

Preferably, a plurality of cams and respective secondary cams are connected in parallel along one axis, spaced along said axis and oriented in angular relative positions, according to respective positions of the engine combustion cylinders and their working sequence.

Using the mechanism according to the present invention enables reducing the height of the engine head by approximately 40%, for example, from 250mm height in a conventional engine, to 150mm. The absence of springs and their associated response-time problem, together with the absence of valve parts within the cylinder chamber interrupting the fuel intake, significantly improves the engine efficiency, momentum and horse-power level relative to conventional spring-valve engines. The fuel consumption is reduced due to increased diffusion of the fuel-air fumes within the cylinder chamber, and the execution of the combustion blast within a completely sealed chamber. The amortization of the sealing regions is significantly reduced due to the external orientation of the sealing lips, and the maintenance of the entire engine becomes easier, because no valve adjustments are required. As opposed to the conventional mechanisms, the treatment (or replacement) of the springless-valves do not require the removal of the engine head. The possibility of mechanical beating between the piston and the valves during high engine speeds is eliminated, because there is no space-sharing between the piston and the externally located valves. In addition, the precise accuracy of the timing chain and timing adjustments between the crankshaft and the camshaft become less significant. Principally, for the permissible timing and mutual adaptation requirements between the synchronous engine parts of the new mechanism of this present invention, a plain transmission belt may be sufficient.

Detailed description of the invention: The present invention will be further described in detail by Figures 1-10.

These figures are solely intend to illustrate one preferred embodiment of the present invention, and in no manner intend to limit its scope.

Brief description of the Figures: Figure 1 illustrates and compares between the conceptual views (in a vertical cross section) of a conventional internal combustion engine, and a springless-valve engine according to the present invention, wherein; Figure 1A illustrates a conceptual view of a conventional engine.

Figure 1B illustrates a conceptual view of the engine according to the present invention.

Figure 2 illustrates a typical cross sectional view of a cylinder of conventional engine, as it looks like during high-speed operation with cams and piston at a 0° angle, at the start of an intake cycle.

Figure 3 illustrates a first vertical cross sectional view via the inlet-valve with a corresponding second vertical cross sectional view of the exhaust-valve, of the springless-valve mechanism according to the present invention with the crankshaft and camshaft at a 0"ange. Figure 3 further illustrates isometric views of the inlet-cam and the inlet-valve, and a top view of the inlet and exhaust cams above their associate valves, wherein; Fig. 3A is a vertical cross sectional view across the inlet-valve.

Fig. 3B is a vertical cross sectional view across the exhaust-valve.

Fig. 3C illustrates an isometric view of the inlet-cam.

Fig. 3D illustrates an isometric view of the inlet-valve.

Fig. 3E illustrates a top view of the inlet-cam and the exhaust-cam located above the inlet-valve and the exhaust-valve, respectively.

Figure 4 illustrates vertical cross sectional views across the inlet-valve and the exhaust-valve, as they are positioned at a 90° angle of the crankshaft-camshaft, during an intake cycle.

Figure 5 illustrates vertical cross sectional views across the inlet-valve and the exhaust-valve, as they are positioned at a 450"ange of the crankshaft-camshaft, during a compression cycle.

Figure 6 illustrates vertical cross sectional views across the inlet-valve and the exhaust-valve, as they are positioned at a 630° angle of the crankshaft-camshaft, during an exhaust cycle.

Detailed description of the Figures: Figure 1 illustrates and compares between the conceptual views (in a vertical cross section) of a conventional internal combustion engine, and a springless-valve internal combustion engine according to the present invention. Figure 1A il ustrates a conceptual view of a conventional engine, while Figure 13 illustrates a conceptual view of the engine according to the present invention. Referring to the conventional engine 1A, a cylinder chamber (1) is shown, with a piston (2) in the 900 position, descending during an intake engine cycle. The fuel-air inlet (3) is in the "open"mode, wherein the inlet valve (4) is fully pressed by the inlet cam (5) into the cylinder chamber (1). The valve spring (6) is fully pressed within the spring-cup (13). Note that the inlet sealing-lip (7) is oriented so as to face the cylinder interior. Also note the fuel-air fumes flowing into the chamber interrupted by the inlet valve head (14) located within the cylinder chamber. The exhaust outlet (8) is sealed by the exhaust valve (9) and held in the"close"mode by the tension of the exhaust valve spring (10) which is fully stretched with the spring-cup (11) raised to maximum, due to the angular positioning of the exhaust cam (12). In comparison, a cylinder chamber (21) of the springless-valve mechanism is shown in Figure 1B, with a piston (22) in the 90° position, descending during an intake engine cycle. The fuel-air inlet (23) is in"open"mode, wherein a cylindrical-shape inlet springless-valve (24) is fully lifted within a cylindrical track (30). The means for lifting the inlet springless-valve (24) are not illustrated in this conceptual figure, and will be described later. However, an inlet cam (25) is shown, in the appropriate angular position so as to allow the valve (24) to be lifted.

Note the inlet sealing-lip (27) orientation, now facing towards the outside of the cylinder chamber (21). Also note the fuel-air fumes flowing into the chamber without obstruction. The exhaust outlet (28) is sealed by an exhaust springless-valve (29) held in the"close"mode by means of the appropriate angular positioning of the exhaust cam (32).

Regarding the above illustrated comparison, several advantages of the engine according to the present invention relative to the conventional engine may be clearly observed; (a) free flow of fuel-air mixture during the intake cycle; (b) lessened amortization of sealing lips due to their orientation towards the outside; (c) springless operation thus not having any dependence on spring response time; (d) simple, maintainable, and replaceable valve mechanism (valves may be easily treated without detaching the cylinder head).

Figure 2 illustrates a cross sectional view of a cylinder of a conventional engine, as it looks during high-speed operation with the cams and piston at a 0° angle, at the start of an intake cycle. Here, a delay in closing the exhaust valve occurs due to the response time of the exhaust-valve spring.

A gap"S"may be observed between the exhaust cam (12) and the exhaust spring-cup (11). As the engine speed increases, the cam (12) revolves faster and faster, until the exhaust spring-cup cannot track the cam and a delay occurs, said delay increasing as the engine speed increases. In this situation, damaging mechanical beating occurs at region"B", between the piston (2) and the regressing delayed valve (9).

As is self evident, no such beating occurs in the new mechanism of the present invention, because no springs (and their associate response time) are involved, nor is there any sharing of space between the piston and the externally oriented valves.

Figure 3 illustrates a first vertical cross sectional view (Fig. 3A) across the inlet-valve (44), with a respective second vertical cross sectional view (Fig. 3B) across the exhaust-valve (49), of the springless-valve mechanism according to the present invention with the crankshaft (40) and camshaft (60) at 0° angle. The piston (42) is in the upper position within the cylinder chamber (41), at the start of an intake cycle. Fig. 3C illustrates an isometric view of the inlet-cam (45), which is comprised of two similar mirroring side cams (45a) (45b), and a central secondary-cam (45c). The side-cam (45a) and the secondary-cam (45c) are also shown in Fig. 3A, with the secondary-cam (45c) positioned within a rocker (58) which may pivot restrictedly around the rocker-axis (59). The rocker (58) has a lower concave arm (58a) which penetrates a recess within the inlet-valve (44). Fig. 3D illustrates an isometric view of the inlet-valve (44) and its recess (44a). Referring again to Fig. 3A, the rocker (58) has an upper concave arm (58b) cooperating with the secondary-cam (45c) for lifting the inlet-valve (44) by means of the penetrating lower rocker-arm (58a), when the secondary-cam (45c) is repeatedly engaged (see Figures 4-5) with the upper rocker-arm (58b) during rotation of the camshaft, forcing the rocker (58) to pivot upwards with the inlet-valve (44) mounted on the lower rocker-arm (58a). Simultaneously, the oblate portion of the side-cams (45a) (45b) occupies position facing the upraised inlet-valve (44), thus allowing for lifting of the valve.

Fig. 3E illustrates a top view of the inlet-cam (45) and the exhaust-cam (52), located above the inlet-valve (44) and the exhaust-valve (49), respectively, wherein their relative positions along the relevant portion of the camshaft (60) are shown. In this Figure it may be observed how the inlet-cam (45) is arranged above the inlet-valve (44) with the two side-cams (45a) (45b) on both sides of the valve (44), and the secondary-cam (45c) in between the two side cams and partly within the rocker (58) which pivots around axis (59).

Fig. 3B, illustrates the exhaust-valve (49) with the exhaust-cam (52) (being rotated clockwise) pressing it down by means of the round protruding portion which begins facing the valve (49) apex. The cams rotate by rotation of the camshaft (60) due to the transmission of the rotation from the crankshaft (40) through the transmission belt (39).

Figure 4 illustrates vertical cross sectional views across the inlet-valve (44) and the exhaust-valve (49), as they are positioned at a 90° angle of the crankshaft-camshaft, during the intake cycle. The exhaust-valve (49) is fully pressed in order to seal the exhaust outlet by means of the round portion of the exhaust-cam (52) facing it. The inlet-valve (44) is almost fully lifted by means of the rocker lower-arm (58a), which is forced upwardly by means of the secondary-cam (45c) engaged with the rocker upper-arm (58b). In the meantime, the oblate portion of the side-cams (45a) (45b-not shown in this Fig.) occupy positions facing the valve apex, thus allowing for lifting of the valve. The cylindrical wall of the cylindrically contoured valve (44) is adapted to firmly contact a ring-shaped sealing lip (or gasket) (56) located near the end of the cylindrical track (55) facing the free atmosphere, for providing a seal between the free atmosphere and the fuel-air mixture piping (54).

Figure 5 illustrates vertical cross sectional views across the inlet-valve (44) and the exhaust-valve (49), as they are positioned at a 450° angle of the crankshaft-camshaft, during a compression cycle (in the context of the present invention, the relative piston cycle is expressed in angles of between 0° and 720° since the crankshaft has to revolve twice for the accomplishment of the four engine cycles of each cylinder, including two fully upward and two fully downward intermittent piston movements, each being the result of a 180° crankshaft rotation). In this position, both valves are fully pressed for sealing the cylinder chamber, by means of the round portions of their respective inlet and exhaust cams (45) (52) that force the valves downwardly toward the sealing lips.

Figure 6 illustrates vertical cross sectional views across the inlet-valve (44) and the exhaust-valve (49), as they are positioned at a 630° angle of the crankshaft-camshaft, during an exhaust cycle. In this position, the inlet-valve (44) is still fully pressed, sealing the fuel-mixture inlet, by means of the round portion of the inlet cam (45a) forcing it downwardly toward the inlet sealing lips. The exhaust-valve is almost fully lifted by means of the compression force of the exhaust gases pressing it upwards, and due to the oblate portion of the exhaust-cam (52) which faces the exhaust-valve during the exhaust cycle, thus allowing automatic lifting of the valve by the pressure of the exhaust gases.