Diesel Motor Co. of America - Assigned Patents

Manufacturers Index - Diesel Motor Co. of America

Diesel Motor Co. of America
New York, NY, U.S.A.
Manufacturer Class: Steam and Gas Engines

Patents

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Patent Number	Date	Title	Name	City	Description
67,207	Feb. 18, 1892	Arbeitsverfahren und AusfÃ¼hrungsart fÃ¼r Verbrennungskraftmaschinen	Rudolf Diesel	, Germany	This is the original German patent for the Diesel Engine.
542,846	Jul. 16, 1895	Method and Apparatus for Converting Heat to Work	Rudolf Diesel	Prussia,, German Empire	Patented in Germany, 28 Feb 1892, #67,207; in Switzerland, 02 Apr 1892, #5,221 and in England, 14 Apr 1892, #7,241. Abstract: My invention has reference to improvements in the methods of and apparatus for converting heat into work. Claims: 1. The herein described process for converting the heat energy of fuel into work, consisting in first compressing air, or a mixture of air and neutral gas or vapor, to a degree producing a temperature above the igniting point of the fuel to be consumed, then gradually introducing the fuel for combustion into the compressed air while expanding against a resistance sufficiently to prevent an essential increase of temperature and pressure, then discontinuing the supply of fuel and further expanding without transfer of heat. 2. In an internal combustion engine, the combination with the cylinder and piston, of a valved suction inlet for air or a mixture of air and neutral gas, a valved fuel feed constructed to gradually discharge the fuel into the cylinder, and means in operative connection with the feed valve for opening the same at the commencement of the working stroke of the piston and for closing the same at a predetermined part of the stroke, substantially as described. 3. In an internal character specified, the combination of a combustion cylinder provided with means for gradually introducing fuel therein up to the point of cut-off, a compressor for air, a reservoir connected with the latter and with the cylinder, and an expansion chamber for the exhaust gases, substantially as described.
608,845	Aug. 09, 1898	Internal Combustion Engine	Rudolf Diesel	Prussia,, Germany	Patented in Spain, 03 Dec 1894, #16,654; in France, 10 Dec 1894, #243,531; in Belgium, 10 December 1894, #113,139; in Luxemburg, 10 December 1894, #2,192; in Italy, 21 Feb 1895, #LXXV, 132; in England, 27 Feb 1895, #4,243; in Switzerland, 05 Mar 1895, #10,134 & 10,135; in Germany, 30 Mar 1895, #86,633; in Hungary, 23 Nov 1895, #4,539 & 20 Mar 1897, #7,876; in Austria, 18 Jan 1895, #46/203 & 22 May 1896, #2,038 and in Denmark, 12 Feb 1896, #393. Abstract: My invention has reference to improvements in apparatus for regulating the fuel supply in slow-combustion motors, and in particular to internal-combustion engines adapted for carrying out the process described in my prior patent, No. 542,846, dated July 16, 1895, which process consists in first compressing air or a mixture of air and neutral gas or vapor to a degree producing a temperature above the igniting-point of the fuel to be consumed, then gradually introducing the fuel for combustion into the compressed air while expanding against resistance sufficiently to prevent an essential increase of temperature and pressure, then discontinuing the supply of fuel and further expanding without transfer of heat. Claims: 1. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel, a supply for compressed air or gas; a fuel-supply; a distributing-valve for fuel, a passage from the air-supply to the cylinder in communication with the fuel-distributing valve, an inlet to the cylinder in communication with the air-supply and with the fuel-valve, and a cut-oil, substantially as described. 2. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel; a distributing-valve for fuel; a cutoff for varying the time and duration of the supply of fuel, and a burner placed in the combustion space and constructed for slow and perfect combustion of the gradually introduced stream of fuel, substantially as shown and described. 3. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel, a supply for compressed air or gas, a hopper, a distributing valve for pulverulent fuel, a passage from the air-supply to the cylinder in communication with the fuel-distributing valve, an inlet-valve to the cylinder in communication with the air-supply and with the valve for pulverulent fuel, and a cut-off for the fuel-supply, substantially as shown and described. 4. In an internal slow-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above .the igniting-point of the fuel, a supply for compressed air, a hopper and distributing-valve for pulverulent fuel, a supply-pipe for liquid- .fuel, a valve or valves leading to the cylinder and communicating with the pulverulent fuel-distributing valve and the liquid-fuel supply pipe, and a cut-off for the fuel-supply, substantially as specified. 5. In an internal-combustion engine, the combination of a supply for compressed air, a feed for pulverulent fuel placed in communication with the air-supply and with the cylinder, and an auxiliary feed for liquid fuel communicating with the cylinder, substantially as specified. 6. In an internal-combustion engine, the combination of a cylinder and piston, a supply for compressed air, a distributing-valve communicating with the air-supply and with a fuel-supply for gradually introducing a unitary, or mixed fuel, into the combustion space, a valve placed between the air-supply and the cylinder, and a reversing gear in cooperation with said valve for starting the motor with the compressed air from the air-supply during part of the working stroke, substantially as and for the purpose specified. 8. In an internal-combustion engine, the combination of a cylinder and piston constructed to compress air or a mixture of air and neutral gas storage-reservoir in communication with the combustion-space of the cylinder, a valve controlling this communication and opening to admit compressed air from the cylinder to the reservoir, and a fuel-feed in communication with said reservoir for the introduction of fuel to the combustion space under the pressure of the compressed air or gas in the reservoir, substantially as dc scribed. 9. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel, a distributing-valve for fuel, and a cut-off for varying the time and duration of the supply of fuel by said valve, substantially as described.
644,798	Mar. 06, 1900	Internal Combustion Engine	Arthur J. Firth	New York, NY	Abstract: My invention relates to improvements in internal-combustion motors of the Diesel type. These engines work on a four-stroke cycle as follows: The combustion of fuel injected from the fuel-valve gives a pressure on the inward stroke of the piston. On the next outward stroke the waste gases or products of combustion are expelled from the cylinder. On the next inward stroke the cylinder fills with fresh air drawn in from the atmosphere. This air is compressed on the succeeding outward stroke to a temperature sufficient to ignite the fuel, which is now injected from the fuel-valve. Combustion of the mixture of air and fuel then ensues and the cycle recommences. For the successful operation of these engines it is essential that the temperature attained by the air in the cylinder during the period of compression on the fourth stroke of the cycle be high enough to cause ignition of the fuel when injected from the fuel-valve. It is also important that on the introduction of the fuel uniform and complete combustion shall take place as quickly as possible. Owing to the large amount of relatively-cooler metallic surface to which the air is exposed at this point and the proximity of the usual water-jacket the loss of heat between the time of compression and that of the admission of the fuel may become so great as to preclude a proper ignition. This may be compensated for by an excessive compression, but only at the expense of additional energy. In the German engines it has been the practice to simply compress the air in the top of the cylinder, thus forming a cylindrical body of air exposed to the combined cooling effect of the entire cylinder end, the piston-face, and a strip around the cylinder equal in length to the circumference of the cylinder and in Width to the distance between the cylinder-head and the piston-face at the outer limit of the stroke. As the strip last mentioned is usually backed by a water-jacket it is readily apparent that the construction gives a very large amount of cooling-surface per cubic inch of enclosed air. Now it is evident that if the metallic surface to which the air is exposed can be diminished the detrimental cooling of feet will be considerably lessened; and the objects of my improvements are to provide a clearance-space in the cylinder of less surface area than has been hitherto employed and to afford facilities for the rapid introduction and ignition of the fuel. Claims: l. In an internal-combustion engine, the combination of a cylinder, a head on said cylinder, a piston in said. cylinder, said piston and cylinder-head being so shaped with respect to each other as to form between them a channel to serve as a clearance-space and ignition-chamber, the longitudinal axis of said channel lying substantially at right angles to the longitudinal axis of the cylinder, substantially as described. 2. In an internal-combustion engine, the combination of a cylinder, a head on said cylinder, a piston in said cylinder, said piston and cylinder-head being so shaped with respect to each other as to form between them a channel, the longitudinal axis of said channel coinciding with the diameter of the cylinder, and lying substantially at right angles to the longitudinal axis of the cylinder, to serve as a clearance-space and ignition-chamber, substantially as described. 3. In an internal-combustion engine, the combination .of a cylinder, ahead on said cylinder having a plane inner face, a piston in said cylinder, having a plane face opposed to the plane face of the cylinder-head and a channel in the piston-face, the longitudinal axis of said channel coinciding with a diameter of the cylinder, and lying substantially at right angles to the longitudinal axis of the cylinder, to provide clearance between the piston and the cylinder-head, substantially as described. 4. In an internal-combustion engine, the combination of a cylinder, a head on said cylinder having a plane inner face, said cylinder provided near said head with a lateral admission-port, a piston in said cylinder, having a plane face opposed to the plane face of the cylinder-head and a channel in the piston-face to provide clearance, the longitudinal axis of the channel lying substantially at right angles to the longitudinal axis of the cylinder, and in a plane passing through the longitudinal axis of the cylinder and the axis of the admission-port, whereby at the outer limit of the stroke the channel and port align, and provide a continuous chamber for the admission of the fuel charge, substantially as described.
654,140	Jul. 24, 1900	Apparatus for Regulating Fuel-Supply of Internal-Combustion Engines	Rudolf Diesel	Bavaria,, Germany	Claim: In an apparatus for supplying a variable quantity of fuel to a combustion-motor, the combination with the fuel-supply, of fuel-forcing means communicating therewith, and supplying at each working stroke of the motor an excess of fuel under a pressure less than the back pressure of the motor, means to allow part of this fuel to return to the fuel, supply under this lower pressure, and means to shut off the return flow and cause the remainder to be forced to the motor under a higher pressure, substantially as and for the purpose specified.
661,369	Nov. 06, 1900	Valve-Gear for Explosive-Engines	FrÃ©dÃ©ric C. Dyckhoff	Grand Est Region,, France	Claim: The combination with the engine and its controlling valves, of a valve-actuating mechanism comprising a driving-shaft, driven shafts arranged circumferentially around said driving-shaft and in constant operative engagement therewith, means for shifting said driven shafts around said driving-shaft and cams arranged on said driven shafts
672,477	Apr. 23, 1901	Oil Pump for Explosive Engines	Arthur J. Frith	New York, NY	Abstract: This invention relates to improvements in oil-pumps for motors, particularly for internal-combustion motors; and the object of the invention is to provide a pump for this purpose which will be regulable either under the control of a speed-governor or of the operator and which will be at the same time simple and effective in operation. The general principle of this pump is similar to that of a form of pump now applied to engines of this class wherein with a view to obtaining certainty in the delivery of small quantities of oil the pump draws in the suction-stroke a much larger quantity of oil than is actually needed. In the return or driving stroke this oil at first is driven through a by-pass back into the reservoir, and at a certain point of the stroke this by-pass is closed and the remaining oil is forced through a check-valve to the fuel-valve of the engine. By varying the time of closure of the by-pass very slight variations in the quantity of oil delivered are easily accomplished. The operation of our invention is somewhat similar, but the connection back to the reservoir is closed at a determinate point of the stroke, the variation in feed being effected by varying the stroke of the pump-piston after such closure. To this end the suction-valve is held open by a spring until the piston reaches such determinate point of its stroke, when it acts through a spring to close the suction-valve, and thus cut off communication with the reservoir, the latter spring then yielding to enable the further movement of the piston. No by-pass is necessary with this arrangement, and the variation of the feed is effected simply and accurately by adjustment of the stroke of the piston by suitable means. All air-bubbles that are drawn in in the suction-stroke remain at the top of the fluid and are driven back through the suction-valve before the latter closes, so that when said valve does close only oil is forced into the engine. Claims: l. In an oil-pump mechanism, the combination with the pump-cylinder, a communication therefrom to a source of oil-supply, and a suction-valve in such communication, of a piston working in said cylinder, means for operating said piston, a delivery connection from said cylinder including a check-valve, a spring for holding the aforesaid suction-valve open and means operated by the piston for closing the said suction-valve before the piston finishes its stroke. 2. In an oil-pump mechanism, the combination of the pump-cylinder, a communication therefrom to a source of oil-supply and a suction-valve in such communication, a piston working in said cylinder, means for operating said piston, a delivery connection from said cylinder including a check-valve, a spring for holding the aforesaid suction-valve open and a spring interposed between the said suction-valve and the piston and operated by the latter to close the valve before the piston reaches the end of its stroke. 3. In an oil-pump mechanism, the combination with the pump-cylinder, of an oil-supply connect-ion communicating therewith, a suction-valve in such connection, a delivery connection from said cylinder including a check-valve, a piston working in said cylinder, a spring between said piston and the suction-valve, and operating means for said piston. 4. In an oil-pump mechanism, the combination with the pump-cylinder, of an oil-supply connection communicating therewith, a suction-valve in such connection, a delivery connection from said cylinder including a check-valve, a piston working in said cylinder, a spring between the piston and the suction-valve, and operating means for said piston comprising a spring for moving it away from the suction-valve and cam mechanism for moving it toward said valve. 5. In an oil-pump mechanism, the combination with the pump-cylinder, of an oil-supply connection therewith, a suction-valve in such connection, a delivery connection from said cylinder including a check-valve, a piston working in said cylinder, a spring between said piston and the suction-valve, and operating means for said piston comprising a part adjustable on said piston, piston-actuating means engaging with such adjustable part and a cam for operating such piston-actuating means. 6. In an oil-pump mechanism, the combination with the pump-cylinder, of an oil-supply connection communicating therewith, a suction-valve in such connection, a delivery connection from said cylinder including a check-Valve, a piston working in said cylinder, a spring between said piston and the suction-valve, operating to close the said valve, means for operating the suction-valve when released from the pressure of such spring, and operating means for said piston. 7. In an oil-pump mechanism, the combination with the pump-cylinder, of an oil-supply connection communicating therewith, a suction-valve in such connection, a delivery connection from said cylinder including a check-valve, a piston working in said cylinder, a spring between the piston and the suction-valve, said valve being adapted to be closed by the operation of said piston acting through said spring, and operating means for said piston comprising a spring for moving it away from the suction-valve and cam mechanism for moving it toward said valve. 8. In an oil-pump mechanism, the combination with the pump-cylinder, of an oil-supply connection therewith, a suction-valve in such connection, a delivery connection from said cylinder including a check-valve, a piston working in said cylinder, a spring between said piston and the suction-valve, said valve being closed by said piston acting through said spring, and operating means for said piston comprising a part adjustable on said piston, piston-actuating means engaging with such adjustable part and a cam for operating such piston-actuating means. 9. In an oil-pump mechanism, the combination with the pump cylinder and piston, suction and check valves controlling the oil supply and delivery connections of said cylinder, means controlled by said piston to engage and close the suction-valve at a determinate point of its stroke, and an operating-shaft, of controlling means adjustable relatively to such shaft, but rotating therewith, means engaging with said controlling means to cause operation of said piston, and a governor responsive to the speed of the engine and controlling the position of said controlling means on its shaft. 10. In an oil-pump mechanism, the combination with the pump-piston and its operating-shaft, of a cone-cam mounted on said shaft to move rotatively therewith but capable of longitudinal movement thereon, means engaging with said cam to operate the pump-piston, a lever connected to said cam, a governor connected to and controlling said lever, and means for adjusting the center of said lever. 11. In an oil-pump mechanism, the combination with the pump-piston and its operating-shaft, of a cone-cam mounted on said shaft to move rotatively therewith, but capable of longitudinal movement thereon, means engaging with said cam to operate the pump-piston, a lever connected With said cam, a governor connected to and controlling said lever, and means for adjusting the center of said lever, comprising an eccentrically-pivoted center for said lever, and means for rotating such center and for looking the same in position. 12. In an oil-pump, the combination With the pump cylinder and piston, of a suction-valve controlling the oil-supply and provided with means for pressing it away from its seat, a plunger Working in the valve-body, and adapted to engage with the piston and with the valve-body, and spring for holding the plunger toward the piston.
		Oil Pump for Explosive Engines	James D. Macpherson	Passaic, NJ
673,160	Apr. 30, 1901	Method of Igniting and Regulating Combustion for Internal Combustion Engines	Rudolf Diesel	Bavaria,, German Empire	Abstract: All internal-combustion engines which compress a combustible mixture and ignite the same at or near the end of the compression in any manner whatsoever allow the combustion which results from the stroke of the piston in any such ignition to take its own course; i.e., they do not regulate or control the ensuing combustion by any action of the machine itself. This neglect leads to important difficulties and irregularities. The governing of such machines is difficult and unsatisfactory. When such governing is attempted by changing the composition or proportion of the mixture while retaining the same apparatus for Igniting, mixtures which contain much combustible matter, as required when Working at full load, often ignite too suddenly and violently, while, on the other hand, the action of mixtures for light loads containing less combustible matter is apt to slow and retarded ignition, because the velocity of propagation of such ignition varies with the proportion of the mixture in very wide limits. Every mixture therefore of a combustible with air or with oxygen follows its own course, different from that of other mixtures, as recorded by indicator-diagrams. The igniting point of a combustible is that temperature up to which the mixture under the given pressure must be heated before the igniting-point combustible will ignite. The igniting point of any given combustible for a given pressure and a given proportion of the mixture of such combustible with air has a constant value, depending on the physical properties of the combustible. On the other hand, different combustibles have different igniting-points under the same condition of mixture and pressure. This variation can be further increased by variation in the pressure or in the proportions of the mixture to which the various combustibles are subjected before or during ignition. If, therefore, in internal-combustion engines regulation or governing is attempted by changing the quantity of the working mixture while keeping its proportions practically constant, the velocity with which ignition is propagated through-the mixture will also vary, because the amount of compression and the resulting temperature must vary with this quantity. Therefore each change in the load will change the course of the combustion but the course of the combustion after ignition vitally influences of the whole process. When the most economical course of combustion has once been determined, it is of the greatest importance to retain such control of the combustion, as to make it follow such course. It follows from the foregoing that if a given mixture is compressed to a degree below its higher than the igniting or auxiliary combustible, then injecting this latter into the first compressed mixture will induce immediate ignition of the secondary fuel and gradual combustion of the first mixture, the combustion after ignition depending on the igniting or secondary combustible. Claims: 1. The method of regulating combustion in internal-combustion engines which consists in producing a mixture of air or oxygen and a combustible, compressing the mixture to a temperature lower than the igniting-point of the combustible, and introducing under excess of pressure into the mixture a secondary combustible, the igniting-point of which is equal to or below the temperature due to the compression, substantially as described. 2. The method of regulating combustion in internal-combustion engines, which consists lower than the igniting-point of the combustible, and introducing under excess of pressure into the mixture a secondary combustible, the igniting-point of which is equal to or below the temperature due to the compression, substantially as described. 3. The method of regulating combustion in internal-combustion engines, which consists in producing a mixture of air or oxygen and a combustible, compressed to a temperature lower than the igniting-point of the combustible, introducing into the mixture a secondary combustible, the igniting-point of which is equal to or below the temperature due to the compression, and regulating the quantity and duration of admission of such secondary combustible while expanding against a resistance, substantially as described.
683,459	Oct. 01, 1901	Valve Gear for Diesel Motor	Arthur J. Firth	New York, NY	Abstract: This invention relates to improvements in valve-gears for Diesel motors or generally for internal-combustion engines operating on the four-stroke or Otto cycle and provided with means for admitting compressed air to start the motor. In such an engine positive operation of the fuel and exhaust valves during the regular running of the engine is only required once in each cycle that is, once in two revolutions of the engine-shaft. On the other hand, in starting the machine it is desirable to admit compressed air at each revolution, so as to obtain greater certainty and effectiveness in starting. My invention provides means whereby the engine may be run on a two-stroke cycle when starting with compressed air and may then be run on a four-stroke cycle with fuel, these operations being accomplished by one and the same mechanism. Claims: 1. In an internal-combustion engine, the combination with the fuel-valve thereof, of main eccentric mechanism operated by said engine once during each revolution of the engine, and auxiliary eccentric mechanism operated by the engine once during every two revolutions thereof, and controlling the operative relation of such main eccentric mechanism with the said fuel-valve, so as to bring said fuel-valve into operation on every other revolution. 2. In an internal-combustion engine, the combination with the cylinder provided with fuel and compressed-air valves, of eccentric mechanism operated by the engine once in every revolution thereof, valve-gear mechanism and means for controlling same to bring either the fuel-valve or the compressed-air valve into operative relation with the eccentric mechanism, auxiliary controlling mechanism operated by the engine once in every two revolutions thereof and controlling the operative relation of the said eccentric mechanism with regard to the valve-gear mechanism so as to bring said valve-gear mechanism into operation once in every two revolutions on a four-stroke cycle, and means for maintaining said auxiliary controlling mechanism in fixed position to cause operation of the valve-gear once in every revolution in a two-stroke cycle. 3. In an internal-combustion engine, the combination with valve-gear mechanism, of eccentric mechanism operated by the engine once in every revolution thereof, auxiliary controlling mechanism controlling the operative relation of the eccentric mechanism with regard to the valve-gear mechanism, means for operating said auxiliary controlling mechanism once in every two revolutions of the engine to cause the valve-gear mechanism to operate on a four-stroke cycle, and means for maintaining the auxiliary controlling mechanism in position to cause the valve gear mechanism to operate once in every revolution on a two-stroke cycle. 4. In an internal-combustion engine, the combination with fuel and compressed-air valves, adjustable valve-gear mechanism provided with means for operation of either the fuel or the compressed-air valve, means for adjusting said valve-gear to bring it into operative relation with either of such valves, and means for operating the valve-gear mechanism on a four-stroke cycle when in operative relation with the fuel-valve and on a two-stroke cycle when in operative relation with the compressed-air valve. 5. In an internal-combustion engine, the combination with fuel and compressed-air valves, adjustable valve gear mechanism adapted to be brought into operative relation with either of such valves, and means for adjusting said valve-gear to operative relation with either of such valves, operating eccentric mechanism operated by the engine on each revolution thereof, auxiliary eccentric mechanism adapted to be operated by the engine on each two revolutions thereof and con trolling the operative relation of the operating eccentric mechanism with the valve-gear mechanism, so as to operate the fuel-valve on a four-stroke cycle, a clutch connection between the engine and the auxiliary valve-gear mechanism, and means operatively connected with the valve-gear-adjusting means to disengage the clutch and hold the auxiliary controlling means in position to continually maintain the operative relation of the main eccentric mechanism and the valve-gear mechanism when the latter is in the air-valve operating position, so as to operate the compressed-air valve on a two-stroke cycle. 6. In an internal-combustion engine, the combination of fuel and compressed air valves, valve-gear mechanism adjustable to engaging relation with either of such valves, operating mechanism operated by the engine in every revolution, auxiliary controlling mechanism operated by the engine in every two revolutions, a clutch controlling the connection of such auxiliary mechanism with the engine and controlling means for said clutch. 7. In an internal-combustion engine, the combination of fuel and compressed air valves, valve-gear mechanism adjustable to engaging relation with either of such valves, operating mechanism operated by the engine in every revolution, auxiliary controlling mechanism operated by the engine in every two revolutions, a clutch controlling the connection of such auxiliary mechanism with the engine and controlling means for said clutch and for the valve-gear, operating to engage the clutch when the valve-gear is in operative relation with the fuel-valve, and to disengage the clutch when the valve-gear is in operative relation with the compressed-air valve. 8. In an internal-combustion engine, the combination of fuel and compressed air valves, valve-gear mechanism adjustable to engaging relation with either of such valves, operating mechanism operated by the engine in every revolution, auxiliary controlling mechanism operated by the engine in every two revolutions, a clutch controlling the connection of such auxiliary mechanism with the engine and controlling means for said clutch and for the valve-gear, operating to engage the clutch when the valve-gear is in operative relation with the fuel-valve, and to disengage the clutch when the valve-gear is in operative relation with the compressed-air valve, and provided with means for stopping the auxiliary controlling mechanism upon disengagement of the clutch, to maintain such mechanism in position to operate the valve-gear on a two-stroke cycle. 9. In an internal-combustion engine, the combination of fuel and compressed air valves, valve-gear mechanism adjustable to engaging relation with either of such valves, operating mechanism operated by the engine in every revolution, auxiliary controlling mechanism operated by the engine in every two revolutions, a clutch controlling the connection of such auxiliary mechanism with the engine and controlling means for said clutch and for the valve-gear, operating in one position to engage the clutch and place the valve-gear in operative relation with the fuel-valve, in another position to disengage the clutch and place the valve-gear in operation with the air-valve, and in an intermediate position to remove the valve-gear from operative-relation with both fuel and air valves. 10. In an internal-combustion engine, the combination of fuel and compressed air valves, valve-gear mechanism adjustable to engaging relation with either of such valves, operating mechanism operated by the engine in every revolution, auxiliary controlling mechanism operated by the engine in every two revolutions, a clutch controlling the connection of such auxiliary mechanism with the engine and controlling means for said clutch and for the valve-gear, operating in one position to engage the clutch and place the valve-gear in operative relation with the fuel-valve, in another position to disengage the clutch and place the valve-gear in operation with the air-valve, and in an intermediate position to remove the valve-gear from operative relation with both fuel and air valves while maintaining the disengagement of the clutch. 11. A valve mechanism comprising two valves, a reciprocating valve-gear having toes adapted to operate either valve according to the angular position of such valve-gear, operating means adapted to operate said valve-gear at two different periodicityâ€™s, and controlling means for causing said valve-gear to come into operative relation with one of said valves when operating at one periodicity, and to come into operative relation with the other valve when operating at the other periodicity. 12. The combination with an engine, of valve mechanism comprising valve-gear, operating eccentric mechanism, auxiliary eccentric mechanism controlling the operative relation of the operating eccentric mechanism with the valve-gear, means comprising a clutch for operating said auxiliary eccentric mechanism from the engine, and disconnecting devices for said clutch comprising a cam device revolving with the clutch and a controlling device engaging such revolving cam device to open the clutch. 13. The combination with an engine, of valve mechanism comprising valve-gear, operating eccentric mechanism, auxiliary eccentric mechanism controlling the operative relation of the operating eccentric mechanism with the valve-gear, means comprising a clutch for operating such auxiliary eccentric mechanism from the engine, and disconnecting devices for said clutch comprising a cam and stop device revolving with the clutch and a controlling device engaging such revolving cam and stop device to open the clutch and stop the auxiliary eccentric mechanism in definite position.