US1931505A - Internal combustion engine - Google Patents

Description

Oct. 24, 1933. c MULLER 15931505 INTERNAL COMBUS TION ENGINE Origineil Filed Jan. 12, 1925 4 Sheets-Sheet l -FIG. I-

WITNESSES lNV I [Mum/22A I W Dct.

WITNESSES W 2m 1933- I c. A. MULLER 1,931,505

INTERNAL COMBUSTION ENGINE Origiiial Filed Jan. 12, 1925 4 Sheets-Sheet 2 Oct. 24, 1933. c MULLER 1,931,505

INTERNAL COMBUSTION ENGINE Original Filed Jan. 12, 1925 4 Sheets-Sheet 3 E'TZ ZMM gag 04%22/ Oct. 24, 1933. c. A. MULLER INTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 4 Original Filed Jan. 12, 1925 Patented Oct. 24, 1 933- 1.931.505 INTERNAL COMBUSTION ENGINE,

Charles A. Muller, Brooklyn, N. Y.

Original application January 12, 1925, Serial No. 1,822, now Patent No. 1,821,662. Divided and glizsaggplication .lanuary 16, 1929. Serial No.

22 Claims. or. res-32) This invention was shown and described in a prior co-pending application, 8. No. 1,822, filed Jan. 12, 1925, which became Patent No. 1,821,662, Sept. 1, 1931.

This invention relates to internal combustion engines, of'the Diesel, or surface ignition" type, wherein the heat produced by compression of the air charge, and that of the surfaces err-- posed to combustion, is used to ignite the fuel charge, and more especially to engines in which the combustible is injected into the cylinders toward the end of the compression stroke of the pistons, and at the beginning of the power stroke. Inengines of the specified type, heretofore known, and especially in those subjected to wide within the limits of safety for the materials of the engine and the lubrication.

This invention is for the purpose of controlling more closely the temperature of combustion at any load under varying conditions for the purpose of realizing the aforementioned maximum efi'iciency.

In carrying out the invention not only is the amount of fuel admitted at each power stroke directly controlled in the usual manner, but an additional control is maintained over the temperature of the air charge before compression in the engine cylinder. The invention also pro= vidcs for indirect control of the discharge pres sure of the compressor through the temperature control coupled with automatic regulating means of the air delivery from the compressor.

Manual control means are also provided to regulate the initial volume of'air trapped in the engine cylinder. These control means are designed to eiicct a decrease in the amount of air admitted to the cylinder when the initial volume is increased to thus effect the desired weight of the air charge trapped.

In connection with the invention is disclosed novel combinations of apparatus and means to introduce immediately before compression a comparatively large portion of the air charge intothe power cylinder, preferably at a higher pressure than that of the portion of the charge already filling the cylinder which has been sup= plied during the scavenging operation.

While there are herein illustrated specific embodiments of the present invention in two stroke cycle constant pressure engines, it will be understood that the invention may be also applied to four stroke cycle engines and to engines of the 60 'constant'volume type. The invention also comprises the various features which shall herein after be described and claimed.

An object of the present invention, is to provide an engine wherein the temperatures are 65 controlled within a range adapted to generate the maximum of power from the quantity of fuel used, irrespective of the variations of load encountered.

A further object of the invention is to supply 70 charges of air for combustion purposes, of suiii cient density to enable the fuel to be combusted *with the maximum emciency.

The application for patent for this invention is a division of application, Serial No. 1822, filed 75 January 12, 1925.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a vertical section of a two cycle internal combusso tion engine of the constant pressure type, showing the essential features of the invention, but omitting certain elements not important to a clear understanding of the same- F'ig. 2, a diagram, illustrating the relative positions between as the points of opening and closing of the supercharging valves shown in Fig. 1, along the circum ference described by the crank pin in a single revolution; Fig. 3, a conventional pressure volume diagram, applicable alike to the engines 00 shownin Figs. 1 and 4; Fig. i, a vertical section of an engine embodying a modified form of the invention; Fig. 5, a diagram, applicable to the engine of Fig. 4, illustrating the relative positions between the points of opening and closing of the 05 superchargins valves, along the circumference described by the crank pin in a single revolution: Fig. 6, a vertical sectionof an engine illustrating a further modified form of the invention; Fig. "l, a diagram applicable to the engine of Fla. 6, show too ing the relative positions between the points of opening and closing of the superchargine valves along the circumference described by the crank pin in a single revolution; and, Fig. 8, a diagram applicable to the engine of Fly. 6, showing the its opening and closing, positions of the mechanh cally operated suction valve for the precompression and discharge of the scavenging and chore ting air.

In the practice of the invention. referring de .llc

or duct, 22. atmospheric air to enter the chamber, 20, during scriptively to the specific embodiment thereof which is herein exemplified as applied to an internal combustion engine of the two cycle type,

shown particularly in Fig. 1 of the drawings, the

scavenging air, and a charging port, 7, are'also provided in the cylinder wall. The piston, 5, is connected to the main crank shaft, 8, by the usual elements, including the piston rod, 9, sliding through the guide or stufling box, 10, and acting through the wrist pin, 11, and connecting rod, 12, which is coupled to the crank pin, 8a of crank 8c. The low pressure scavenging air entering the port, 6, is supplied by any convenient means, such as the air pump cylinder, 13, the piston, 14, of which is connected to the crank shaft, 8, by the connecting rod, 15, crank, 8e, and crank pin, 8a. The pump, 13, has a suction valve, 16, and a discharge valve, 1'7, which delivers air into the pipe, 18. From the pipe, 18, the air is delivered through the jacket, 18a, the duct, 19, and port, 6, to the cylinder, 2.

The .air used for supercharging is compressed by the piston, 5, the under or concave side of which acts as a compressor piston and compresses the air between the lower part of the cylinder, 2, and the inside of the piston, which forms, with the stufling box wall, 10, a chamber, 20, and is discharged through the valve, 21, into a receiver The suction valve, 23, allows the the in-stroke of the piston, 5. From the duct, 22, the supercharging air passes through the pipes, 24, into the valve chest, 25, oi, the main charging valves, 26, and, 60. The valve, 26, is mounted on a rod, 28, actuated by the spindle, 29, which slides through the stuffing box, 30, and is driven by links, 31, connected to a bell crank lever, 32, and a pin, 33, on the crank shaft, 8. The valve, 26, controls the passage of air into the cylinder, 2, through the charging port, 7, and the valve, 60, which is also mounted on the rod, 28, controls the admission of air from the valve chest, 25, into the intermediate space, 34. The valve, 60, is normally held down .on its seat, and the valve, 26, across the port, 7, by means of a spring, 28a, and both these valves are opened by the upward movement of the rod, 28, caused by the elevation of the upper end of the spindle, 29. The intermediate air space, 34, communicates with the firing chamber, 35, through the poppet valve, 36.

The poppet valve, 36, is operated by a. valve stem, 37, connected through the linkage, 38, to the pin, 33. All of the air used in the engine is heat controlled after precompression, the heat regulation being effected by lay-passing the air by means of the valves, 39, and, 40, actuated by any suitable means such as the rod, 41, situated at the outlets of the auxiliary heating elements or tubes, 42, and, 43, which are connected respectively with the pipes, 18, and, 22, and can be heated by a common source of heat, such as the burner, 44, located near the point at which the air enters the heating tubes, 42, from the pipe,

pipe, 4. The'pipes or ducts, 18, and, 22, form jackets, 18a, and 22a, respectively, around the exhaust pipe, 4, so that the air passing through such jackets becomes heated.

The scavenging or low pressure charging air emanating from the air pump, 13, is directed automatically through the jacket, 18a, or the tubes, 42, into the duct, 19, leading to the port, 6, or through both in proportional amounts as controlled by the position of the valve, 39.

The supercharging or higher pressure at emanating from the compressor chamber, 20, Within the piston, 5, is directed as desired into the jacket, 22:1,, or through the tubes, 43, or through both in proportional amounts as controlled by the position of the valve, 40, discharging through the pipe, 24, into the valve chest, 25, of the inlet valve, 26. The valves 39 and 40, are manipulated by the rod, 41, which,bears an integral locking spur, 46, intended to be engaged by the hand controlled latch, 47, so that when the latch is moved into the position shown in Fig. 1, the valves, 39, and, 40, will be closed and the air in the pipes, 18, and 22, will be forced to pass, respectively, through the tubes 42, and, 43. The free end, 48, of the rod, 41, is

engaged by the end, 49, of the bell crank lever,

50, which is operatedby the stem, 51, of a thermostatic regulator, 52.

The regulator, 52, has a fluid chamber, 53,

which extends over the wall, 54, at the end 012105 the combustion chamber of the cylinder, 2, in such manner as to expose most effectively the thermostatic fluid in such chamber to the variations of the highest temperatures reached by the wall or walls, and communicates with the expansion chamber, 55. The fluid is allowed to expand to the expansion chamber, 55, by reason of the expansible wall, 56, thereof, which at its outer edge is secured to the flange of the stem, 51. The inner end of the stem, 51, slides freely in the guide, 57, formed on the exterior of the cylinder, 2, by which the stem, 51, and the wall, 56,\are supported and held in position.

It will thus be seen that as the stem, 51,

tion or expansion of the thermostatic fluid, it will cause the rod, 41, through the lever, 50, to

operate the valves, 39, and, 40, and thus control the amount of heat applied both to the scavenging air and the high pressure air, by regulating the amount of such air passing through the jackets, -18a and 22a.

Before starting the engine, the rod, 41, is lifted and locked in the position shown in Fig. 1, by the latch, 47, thus closing the valves, 39, and, 40, so that the air entering the pipe, 18, from the pump, 13, must pass through the tubes, 42, and the air from the compressor chamber, 20, must pass through the tubes, 43. With the parts in such positions, the burner, 44, is lighted, and heats the tubes, 42, and, 43, The engine is then started by any of the usual methods, and the air from the pump and compressor circulates through the tubes, 42, and, 43. As soonfas the exhaustduct, 4, becomes sufliciently heated, the burner, 44, is extinguished, and the rod, 41, is released from the latch, 47. This permits the upper end, 48, of

the rod, 41, to engage with the end, 49, of thebell crank lever, 50, of the thermostatic regulator, 52. Before the cylinder, 2,,is warmed up, the thermostatic fluid is contracted in the'expansion chamber, 55, and the expansible wall, 56. of such chamber is likewise contracted under the action of, atmospheric pressure, and the weight of the rod, 41, as applied to the outer end of the stem, 51, thus causing the valves, 39 and, 40, to be opened to the entire fullest extent, and the bypasses closed, so that the scavenging air will pass through the Jacket, 18a, and the entire supercharged air will pass through the Jacket. 22a, and will thus be exposed to the heating effect 01 the exhaust, 4. Then, as the cylinder heats up, the thermostatic fluid will expand and by its movement of the rod, 41, will vary the amount of the opening of the valves, 39, and, 40, and thus regulate the passage of the air through the Jackets, 18a, and 22a, and by-passes. If desired, the heating elements, 42, and, 43, may act as radiating or intercooling elements, since an opening, 58, may be provided about the burner, 44, to permit the admission of a cooling element to pass through the auxiliary chamber, 44a,'so that, un derpealr or overload, when the valves, 39, and, d0, are closed, the air passing through the elements, i2, and, 43, will be cooled, and the temperature of the cylinders accordingly reduced.

Referring now to the diagram of Fig. 2 in con nection with the operation of the engine of Fig. i, when the crank pin, moving in the direction of the arrow, reaches the point, a, or the diagram, the exhaust port, 3, is uncovered by the piston, 5, on its out stroke and the exhaust begins. At this point the engine piston has entirely uncovered the cylinder port, 7, but the valve, 26. has not yet opened up the opposite end of the port, 7. Following the out stroke oi the piston the port, 6, is uncovered, thus admitting low pressure air to enter for the scavenging action. But this function is not shown in the diagram crris. a

When the cranls pin reaches the position cor= responding to the point b of the diagram, the valve, 36, opens and the air trapped in the inter= mediate space, 3%, which has definite predetermined volume, encounters the relatively small and decreasing resistance in the cylinder, 2, due to the prior opening 01' the exhaust port, 3, so that the air in the space, 34, expands into the cylinder clearance, 35, and scavenges the upper portion of the cylinder, 2. During the movement of the crank pin, 80., from its point, b, to point, e. the valves, 26, and, 80, are still closed, so that there is no live air or direct connection with the source of the compressed air.

,When the cranl: pin reaches the point, e, the valves, 26, and, do, begin to open, and live air ilows through the space, 34, and through valve, 86, and inlet port, 7, respectively. Since the exhaust port, 3, is about to be closed at point, d, by the piston, 5, practically none of the live air is lost through the exhaust, as the mechanism is so timed that the valves, 26, and, 60, in opening have merely a lead over the exhaust closure.

The only eiilect of this lead is to accelerate the egress of the exhaust gases through the exhaust port, 3, for a relatively short space of time. When the crank pin, 8a, reaches the point, e, the piston, 5, closes the port, '7, at its upper edge, e, and the valve, 36, is then closed, thus inter rupting the flow of live air to the cylinder and ending the period of supercharging which began at the point, d, as is indicated by the cross hatched section of Fig. 2. The valves, 26, and, 60, remain open, and the air supply fills the space, 34, to pressure until these two valves close at the point, i, of the diagram.

During the operation of the engine, the regulation of the heat of the charging, supercharging and scavenging air is normally done automaticaliv. The heating affects the pressure or discharge of the compressors, and when the pressure is increased it operates to decrease the amount of air delivered by the said compressors, as a relatively large fixed clearance is provided in these compressors that will retain or absorb a greater proportion or weight of air at the higher pressure. Thus the heating of the air decreases automatically the amount of air used for charging, supercharging and scavenging, when the engine load decreases; while when the discharge pressures of the compressors are de creased, the weight of the air used for charging, supercharging and scavenging is increased.

In the conventional pressure volume diagram shown in Fig. 3, the point, it, corresponds to the position of the piston when at the extreme end of its power or outstroke; the exhaust port, 3,

is closed by the piston when it reaches the point, d, and the charge would be compressed along the line, d-k, unless supercharging takes place through valves or ports that close when the piston is in line with the point Z, and moves to point, we, straight compression takes place and the piston reaches the extreme end of the imstroke when in line with points, m, it, and, g, the distance, g, to, 0, representing the remaining space in the cylinder, or the fixed clearance. The pressure is maintained constant from the point, m, to, n, by the combustion of the fuel, and the expansion line, n, to a, is interrupted when the exhaust port is opened by the piston now in line with the point, a, and the gases-are discharged from the cylinder while the-piston travels toward the point, it, and returns to, d. During most of the exhaust period, low pressure air is blown into the cylinder to scavenge it, and, while its action is not represented on the dia gram of Fig. 3, it is assumed that the cylinder is full of pure air at atmospheric pressure at point, d. I

In the embodiment of the invention shown in Fig. 4, the air pump, 13, has a double acting piston, 14*, and, therefore, two inlet valves, 16, and two discharge valves, 17 The air for supercharging, which is supplied by the pistons, 5 acting as compressors, is discharged into the receiver or duct, 22 and through jacket, 2212, around the exhaust pipe, 4 and duct, 24 to the valve chest, 25. The air is regulated by the thermostatically controlled valve, s0 and by the manually operated valve, 65. The air may be passed from the duct 22 to the duct 24 either around the heating Jacket 2212 or through the pipe 66, according to the position or the valve, 40 or it may be directed through the pipe, 67, and the heating unit, 43 to be heated at starting, according to the position oi the valve 65; or both the valves, 40 and, 65, may be used for regulation at one time. No provision is here shown for heating the air passing through the pipe, 18 through which the air for scavenging is supplied.

The valves, 36a, and, 36b, have stems, 37 connected to the beam, 68, which is driven by the eccentric, 33 through the linkage, 69, shown as containing a Stephenson link, '70.

Before starting the engine, the valve, 40 because of the contraction of the thermostatic the linkages, 31

through the heating unit, 43 and the initial temperature of the air is thus elevated. As soon as the exhaust pipe, 4 carries a sufficient amount of heat, the valve, 65, is shifted to close the pipe, 6'7, and open t e duct, 22 to the heating jacket 22b, and the urner, 44 is extinguished and thereafter the passage of the air to the heating jacket, 22b, is controlled by the thermostatic regulator, 52 which controls the valve 40 which valve 40 in regular operation by-passes part of the air through the branch, 66, while the remainder flows through the duct, 22 to the main heating unit, 22b.

The operation of the valve, 60 is limited to supercharging the cylinders, 2 through the valves, 36a, and 36b. The valve, 60 controls the filling of the intermediate space, 34 twice in one revolution of the crank shaft, 8 opening when the crank pin, 8b, reaches the point, 0 indicated on the diagram of Fig. 5, and closing when the point, f is reached; it opens again when the crank pin, 8b, reaches the point, c the valve, 361), being closed, but the valve, 36a, being open, and the crank pin, 8, isat the point, 0 thus indicating the beginning of the supercharging of the left hand cylinder, 2 closes again when the crank pin, 8b, is at the point, I and the diametrically opposed crank, 8", is at the point, f The lead of the opening supercharging valves over the closing of the exhaust is indicated by the arc,'c to, d but practically the arc, (U, to, e indicates the period of supercharging, since the valves, 36a, and, 36b operate in the same way as the valve, 36, of the engine shown in Fig. 1. I

As the valve, 60 is operated by the wrist pin, 11, and beam, '71, the beam being connected to to the wrist pin 11 at one end by a link and pivotally connected at its opposite end to a fulcrum suitably fixed to the engine, it will open when either crank pin, 8'', or, 8, moving in reverse direction, arrives at point, I while the exhaust ports are closing in the same cylinder, and it will function equally well for the engine moving in either direction, and is adapted to reversible engines.

The valves, 36a, and, 36b, are operated through the Stephenson link, '70, by which they may be made to operate with the engine running in reverse. Furthermore, while running in either direction, the regulation of the time allowed for each supercharge to enter the cylinders, 2 is effected by adjusting the position of the link arc, and such adjustment will have the effect of lengthening or shortening the length of the arc, d -e of Fig. 5. When the arc, d -e is shortened, the time allowed for supercharging is less, but the volume of air trapped in the engine cylinder is larger, since the arc, e -g is correspondingly increased; this arrangement gives the operator a means of adjustment between the initial cylinder pressure and volume, as said pressure will drop when the net period, d e of, valve opening is decreased, and the initial volume increased.

In Fig. 6, is shown the application of the invention to .a further form of twoecycle engine, in which the rod, 12 connects directly the piston, 5 and crank pin, 8. .The crank case, '72, is made air tight, and hence acts as a pump casing. The valves, J26 ,a'nd, '75, are mounted on the stem, 29*, and operated by the eccentric, 33 through The scavenging air is drawn in during the in or up stroke of the piston, 5 through the suction port, '73, the valve controlled The valve, 60

ports, '74, the valves, '75, and, 26 and passages, '76, and, 7'7, to the crank case, '72, the suction covering the space between the points, c and, 11', of the diagram shown in, Fig. 8. During the out-stroke of the piston, 5 compression occurs between the points, a, and, 0 Following this the air is discharged between points, 0 and, e from the crank case, '72, into the cylinder through the same passages, '77, and, '76, the valve, 26 and the port, 7 (which performs substantially the functions of the ports, 6, and '7, of Fig. 1) controlled on one side by the valve, 26 and on the other by the piston, 5

The air used for supercharging is supplied by the air pump from the supply of scavenging air, and is therefore at a relatively low pressure. All of the air used in the engine is temperature controlled both before precompresslon and after precompression, since during suction it is drawn down through the passages, '76, and '77, around the heating tubes, 80. Any suitable source of heat for heating the tubes, 80, may be located in the opening, 81. When the engine is running, the exhaust gases are led out through the exhaust, 4 which has a thermostatically controlled valve, 82, by which the exhaust gases may be passed through the heating tubes, 80, or may be by-passed directly into the free exhaust branch, 83. The thermostatic control may be held out of, or brought into, operation by the latch, 851, which engages a spur, 85, onthe lever, 50

When the engne is running, the air is made to travel twice at each turn of the crank shaft, through the spaces, '76, and, '77, around the tubes, 80, thereby absorbing sufficient heat to raise the initial temperature and the temperature after compression to induce ignition of the fuel when injected into the cylinders.

When the engine temperature increases, and the walls of the cylinder nearest the thermostatic regulator, 52 become heated, the fluid in the thermostat expands, with a resultant movement of the valve, 82, that by-passes part of the exhaust into the branch, 83, thus lowering the heating effect of the tubes, 80, upon the air which flows around said tubes. The thermostatic regulator, 52 follows the variation of the in-.

temal temperature and operates the valve, 82, thereby adjustingat all times the,heating of the air charges, and maintaining the highest degree of efficient combustion at all loads.

The operation of the multiple piston valves, 26 and, '75, can be visualized by Fig. '7, showing the exhaust opening at'the point a while the valve, 26 is still closing the ports, '7 so that the exhaust gases cannot enter the valves, as these are filled with part of the .resh charges. When the crank pin, 8d, passes the point, 0 of the diagram of Fig. '7, the valve, 26 opens to the port, '7 and air entering the cylinder therethroughscavenges and charges the cylinder until the piston, 5 closes the exhaust port, 3 at point, 11 of the diagram, and the air continues to flow through valve, 26 thus supercharging until the piston closes the port, '7 at point, e of the diagram of Fig. '7. When at point, e the valve, 25?, is fully open and does not interfere with an a bundant flow of air, until it is suddenly interrupted by the piston, 5 at the point, c of the diagram, while the valve, 26 does not close until later at the point, F. The compression begins ."when the crank pin, 8 is at the point, 6 and ends at the top center, g the extent of the power stroke being from, 9 to a r Thus the invention provides an engine in which 15c over the volume of air trapped in the power cylinder, and furthermore, the weight of the air charge will be decreased when the temperature is increased, and increased when the temperature is decreased.

'llhe invention further provides for introducing immediately before compression, a subsequent and comparatively large portion of the air charge into the power cylinder, at a higher pres= sure than the initial portion oi charge already filling the chamber.

it will thus be seen that the invention provides means for regulating the temperature oi the air previous to its being introduced into the cylinder, and so delivering the air to the cylinder that it will be of the desired temperature when delivered, varying in degree in a manner dependent upon the variation in temperature of the cylinder wall. This is preferably accomplished by passing the air through two branches for independent tem-- perature treatment, and then selectively drawing from these two branches respective quantities to obtain the desired results in the charge admitted to the cylinder. The quantity selection being dependent upon variations in the temperature in the cylinder wall. I

It will be seen from the foregoing that the temperature=regulating contemplated, regulates the temperature of the cylinder wall, the temperature of which in turn is the agent employed that regulates the temperature=regulating oi the wall itself.

The invention claimed as new, and desired to be secured by Letters Patent is:

1. In an internal combustion engine the combination of a power cylinder; a piston therein; a

supercharging air compressor; a branched duct leading from the supercharging air compressor to the power cylinder; valve means controlling the admission or supercharging air to the power cylinder; a scavenging air compressor; a branched duct leading from the scavenging air compressor to the power cylinder; heating means for a branch or each oi the ducts; means adapted for heating or cooling the air in another branch of each of the ducts; thermally energized means for varying the relative proportions of air conveyed through the branches oi each oi the ducts, responsive to variations of temperature of the cylin der walls; and means cooperative with the piston adapted to operate the valve means to cause some to admit air to the power cylinder at predator mined positions of the piston.

2. In an internal combustion engine, the combination of a'power cylinder provided with independent air and fuel inlet means for the introduction of the power charge thereto; two-part air supply means in communication with said air inlet means; means for heat-treating said supply means, including a heating element for one part, of said supply means operably dependent upothe heat of the cylinder, and-a heating element for the other part of said supply means operably independent of the heat, of the cylinder; and means automatically responsive to temperature changes in the cylinder wall for varying the quantity of air introduced from the respective parts, from the part having the dependent heat-= ing element inversely, and from the other part directly with said changes. a

3. In an internal combustion engine, the com= bination of a power cylinder provided with independent air and fuel inlet means for the introduction of the power charge thereto; two-part air supply means in communication with said air inlet means; means for heat-treating said supply means, including a heating element for one part of said supply means operably dependent upon' the heat of the cylinder, and a heating element for the other part of said supply means operably independent of the heat oi the cylinder; means automatically responsive to temperature changes in the cylinder wall for varying the quantity of air introduced from the respective parts, from the part having the dependent heating element, inversely, and from the other part directly with said changes; and means for closing the part having tthe dependent heating element from said a. In an internal combustion engine, the com bination oi a power cylinder provided with an air inlet and a fuel inlet iorthe introduction of the power charge thereto; a main air supply pipe for the air inlet; two branch feed pipes opening into said main pipe; means associated with one oi said branch pipes adapted for heating the air passing through said branch pipe by the engine waste gases; valve means operable to vary inversely the proportionate quantities of air fed irom the feed pipes to the main pipe; and means automatically responsive to temperature changes in the cylinder wall for operating said valve liiii 'means to vary the quantity of air fed from the reed pipe heated by the waste gases, inversely to the temperature changes of the cylinder wall and the quantity or air led from the other iced pipe directly with said temperature changes.

5. In an internal combustion engine, the combination of a power cylinder provided with an air inlet and a fuel inlet for the introduction of the power charge thereto; a main air supply pipe for the air inlet; two branch pipes opening into said main pipe; means associated with one of said branch pipes adapted for heating the air passing through said branch pipe by the-engine waste r gases; a source oi compressed air for the said branches; valve meansoperable to vary inversely the proportionate quantities of air fed from the teed pipes to the main pipe; and means auto matically responsive to temperature changes in the cylinder wallior operating said valve means to vary the quantity of air feel from the feed pipe heated by the waste gases, inversely to the term perature changes of the cylinder wall and the quantity of air led from the other iced pipe directly with said temperature changes.

6. In an internal combustion engine, the com- 1140 bination of a power cylinder provided with an air inlet for scavenging air; means, in communi-v cation with said air inlet for heat treating scavenging air for the cylinder; and means auto= matically responsive totemperature changes in M5 the cylinder for varying the quantity of said treated air introduced inversely to said tempera= ture changes.

'i. In an internal combustion engine, the com== bination of a cylinder, one end of which operates 5150 as a combustion power cylinder, and the other end as an air compressor cylinder; a piston operating in'thecylinder as the piston for both the combustion engine and air compressor; means for reciprocating the piston; an air supply chamber, communicating withthe combustion power end of said cylinder; means connecting said supply chamber with the air compressor end of said cylinder for receiving the separate charges of air from the air compressor end of said cylinder at each compressing stroke of the piston for said compressor; a valve for preventing the return of the charges to the air compressor end of said cylinder; air discharge control means from the chamber to the combustion power end of said cylinder; means operatively connected to the piston reciprocating means for actuating said control means in timed relation with the forcing of the charges of air into said chamber; heating means in said supply chamber for affecting the temperature and pressure of the air charges therein; and means automatically responsive to temperature changes in the power end of the cylinder wall to vary the amount of air heated by said heating means.

8. In an internal combustion engine, the combination of a power cylinder provided with independent air and fuel inlets for the introduction of the power charge thereto; an air compressor; an air supply chamber intermediate the compressor and cylinder, divided into two parts; means for introducing the compressed air from the compressor to the chamber and preventing the return of the air from the chamber to the compressor; means for conveying the charge of the compressed air from the two parts to the cylinder through said air inlet; heat treating means associated with each of the said parts adapted to heat the air as it passes through said parts to increase the pressure of said air, one of said treating means being heated by the engine waste gases; and means automatically responsive to temperature changes in the cylinder wall for varying the quantity of air conveyed. from each part, the quantity conveyed from the part heated by the engine waste gases being varied inversely and the quantity from the other part being varied directly with said changes and the"pressure of the conveyed charge being thereby varied in response to said changes.

9. In an internal combustion engine, the combination of a power cylinder provided with air and fuel inlet means for the introduction of the power charge thereto; two air supply means for supplying air to the air inlet means; means for heating air passing through one supply means from the engine waste gases; and means automatically responsive to temperature changes in the cylinder wall for varying the quarrtity of air introduced from the respective supply means, for varying the temperature of the air supplied to the air inlet means, the quantity of air supplied from the air supply means adapted to be heated by the engine waste gases being varied inversely,

- and the quantity of air supplied from" the other air supply means being varied directly, with said changes.

10. 131 an internal combustion engine, the combination of a power cylinder provided with independent air and fuel inlets for the introduction of the power charge thereto; an air compressor; a

L two-part duct for receiving compressed air from the compressor; means for conveying the compressed air from the duct to the cylinder through said air inlet; heat-treating means asseciated with one of said parts, adapted to vary the pressure of the compressed air while in said duct; and means automatically responsive to temperature changes in the cylinder Wall for varying the quantity of air treated in said duct.

11. In an internal combustion engine, the combination of a power cylinder; a piston therein; a two-part duct for conveying charging air to the cylinder; a main valve for admitting air from the duct to the cylinder; an air chamber intermediate the duct and the cylinder; means for admitting air from the duct to the chamber; a valve for admitting air from the chamber to the cylinder; means for heating air in one part of said duct; means for controlling the relative flow of air through said duct parts; means responsive to the temperature changes in the cylinder wall operatively connected to said controlling means; and means cooperative with the piston adapted to operate said valves to cause them to admit air to the cylinder at predetermined positions of the piston.

12. In an internal combustion engine, the combination of a power cylinder; a piston therein; a

1 compressor for compressing air for the power charge of the cylinder; inlet and egress valves for the compressor; a branched duct for conveying charging air from the compressor to the cylinder; a main valve for admitting charging air from the duct to the cylinder; a second compressor for compressing scavenging air for the cylinder; a branched duct for conveying the scavenging air from said second compressor to the power cylinder; heating means for a branch of each duct; air temperature control means in another branch of each duct; means responsive to temperature changes in the cylinder wallfor varying the relative proportions of air conveyed through the respective branches of each duct; and means cooperative with the piston adapted to operate said main valve at predetermined positions of the piston.

13. In an internal combustion engine, the combination of a power cylinder; a piston therein; a branched duct for conveying air to the power cylinder; a main valve. for admitting air from the duct to the cylinder; an air chamber intermediate said duct and said cylinder; means for admitting air from the duct to the chamber;

a valve for admitting air from the chamber to the cylinder; heating meansnfor the branches of the duct; means for varying the relative proportions of air conveyed through the respective branches of the duct; means responsive to the temperature changes of the cylinder wall, conair inlet means; means for independentlytreating each part of said supply means for varying the temperature of the air of each respective part,

one of said treating means being adapted to be heated by the engine waste gases; a source of compressed air for said air supply means; and means automatically responsive to temperature changes in the cylinder wall for varying the relative quantities of air introduced from the respective parts of the supply means, thequan- I tity of air introduced from the part having treating means adapted to be heated by the engine waste gases, being varied inversely, and the quantity of air introduced from the other part being varied directly, with said changes.

15. In an internal combustion engine, the combination of a power cylinder provided with an air inlet for scavenging air; two-part air supply means in communication with said air inlet; means for independently treating each part. of said supply means for varying the temperature ofv the air of the respective parts, one of said treating means being adapted to be heated by the engine waste gases; and means automatically responsive to temperature changes in thecylinder wall for varying the quantity of air introduced from the respective parts, the quantity of air introduced from the part having the heat-- 7 treating means adapted to be heated by. the

engine waste gases, being varied inversely, and the quantity of air introduced by the other part being varied directly, with said changes.

16. In an internal combustion engine, the combination of a power cylinder provided with independent air and fuel inlets for the introduction of the power charge thereto; a compressor for compressing air for said cylinder; a supply chamber intermediate the compressor and. the cylinder for receiving air from the compressor; heattreating means associated with said supply chamber for heating the compressed air therein; means responsive to temperature changes in the cylinder wall for varying the amount of air heattreated in said chamber inversely to the changes in temperature of said wall; means for conveying air from the chamber to the cylinder for charging the cylinder; and means for conveying a portion of air from the chamber to the cylinder for scavenging the cylinder.

1'7. In an internal combustion engine, the combination of a power cylinder provided with independent air and fuel inlets for the introduction of the power charge thereto at one end of the cylinder; an inlet for scavenging air at said end of the cylinder; an air compressor; an air supply chamber, adapted to receive airfrom said compressor; means for conveying a portion of the air from said chamber to the cylinder through the charging air inlet; means for conveying another portion of said air from the chamber to the cylinder through said scavenging air inlet.

for scavenging the cylinder; heat-treating means associated with said chamber; a second compressor for compressing scavenging air; a second chamber for receiving air from the second compressor; heat-treating means for the second chamber; means for conveying air from the second chamber to the cylinder at a point further removed from the fuel inlet end of the cylinder than the said scavenging air inlet, for further scavenging the cylinder; and means re-. sponsive to temperature changes in the cylinder 18. In aninternal combustion engine, the combination of a power cylinder provided with in-' dependent air and fuel inlets for the introduction of the power charge thereto; an air compressor having a relativelylarge clearance volume; a two-part chamber for receiving compressed air from the compressor; means for conveying the charge from the chamber to the cylinder through said air inlet; heat-treating means associated with one of said parts, in cooperation with said compressor clearance during the compression stroke to vary the weight of the air charge delivered from the compressor and thereafter to vary the pressure of said charge; and means automatically responsive to temperature changes in the cylinder wall for varying the relative quantities of air passing through the respective parts of the chamber to vary the amount of air heat-treated inversely to said temperature changes.

19. In an internal combustion engine, the combination of a power cylinder; means for introducing air into said cylinder; means for preheating said air; and control means for said preheating means automatically responsive to temperature changes in the cylinder wall adapted to vary the amount of preheating inversely to said temperature changes.

20. In an internal combustion engine, the combination of a power cylinder; air heating means; air compressing means; means for conveying the heated and compressed air to the cylinder; and means automatically responsive to temperature changes in the cylinder wall for varying the amount of air heated inversely to said temperature changes.

21. In an internal combustion engine, the combination of a power cylinder; an aircompressor; means for heating compressed air from said compressor; means for conveying said heated compressed air to the cylinder; and means automatically responsive to temperature changes in the cylinder wall for varying the amount of air heated inversely to said temperature changes.

22. In an. internal combustion engine, the combination of a power cylinder providedwith independent air and fuel inlets for the introduction of power charges thereto; an air compressor; means for heating compressed air from said compressor; means for conveying said heated compressed air to the air inlet of the cylinder; and means automatically responsive to temperature changes in the cylinder wall for varying the amount of air heated inversely to said temperature changes.

- CHARLES A. MULLER.

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