US2213418A

US2213418A - Two-cycle combustion engine

Info

Publication number: US2213418A
Application number: US298496A
Authority: US
Inventors: Bernard A Swanson
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-10-07
Filing date: 1939-10-07
Publication date: 1940-09-03
Anticipated expiration: 1957-09-03

Description

S 3; 1940. I B. A. SWANSON 7 2,213,418

TWO-CYCLE COMBUSTION ENGINE Filed 001;. 7, 1939 2 Sheets-Sheet 1 art 0W TtSQTL B. A; SWANSON TWO-CYCLE COMBUSTION ENGINE Sept; 3, 1940.

2 n t J W .W %M w w \w 7 a My m 9 7 Patented Sept. 3, 1-940 UNITED STATES 4 PATENT OFFICE 18 Claims.

This invention relates to improvements in internal combustion engines and pertains particularly to an improved two-cycle engine.

. One of the principal objects of the present invention is to provide an improved two-cycle internal combustion engine wherein there is provided a new and novel means of feeding the motive fuel such as gasoline or the like into the engine under pressure, dispensing with the usual carbureter, valves, cam shafts, etc., which are necessary in the ordinary type of gasoline motor.

Another object of the invention is to provide an improved two-cycle gasoline engine employing a novel pressure system by means of which lubricant is forced to the moving partsof the machine and the gasoline or other motive fuel is forced through a suitable mixing or carburetting valve into the engine cylinder when the fuel inlet to the cylinder is opened or uncovered by the piston operating therein.

A further object is to provide a novel twocycle internal combustion engine in which novel means is employed for vaporizing the liquid fuel prior to its injection with air into the engine cylinder. v

A still further object is to provide in an engine of the character described, a novel means for introducing air into the lower part of the cylinder beneath the piston for compression by the piston as the same moves downwardly, whereby the introduced air is circulated in such amanner as to facilitate the cooling of the piston.

Still another object is to provide an engine of the character stated having a novel oil and fuel feeding means, in which a novel arrangement is provided whereby the oil and fuel feeding means will continue to function regardless of the angle at which the engine may be disposed, thereby making the engine particularly suitable for airplane use.

Still another object is to provide in a twocycle engine of the character stated, a novel fuel and air injector unit which is so designed that the air when introduced will flow ahead of the the showing of the drawings but may be changed or modified so long as such changes or modifi- 55 cations mark no material departure from the fuel and thoroughly scavenge the engine cylinsalient features of the invention as expressed in the appended claims.

In the drawings:

Fig. 1 is a vertical sectional view through a single cylinder engine constructed in accordance with the present invention showing connected 1 therewith and in section the lubricating oil receptacle and fuel receptacle.

Fig. 2 is a sectional view on the line 22 of Fig. 1. 0

.Fig. 3 is a view in bottom plan of the piston.

Fig. 4 is a sectional view on the line 44 of Fig. 2.

Fig. 5 is a view in elevation showing the linkage between the movable units ofthe mixing 15 valve by which the units are moved in unison. Fig. 6 is a sectional view on the line 6-6 of Fig. 1.

Fig. 7 is a detail view on an enlarged scale of the swivel joint for a swing spout. 20

Referring now more particularly to the drawings, the numeral l generally designates the cylinder block 4 of the present engine structure, the cylinder block at its lower end being flanged as indicated at 2, for support upon the bottom block 25 3 to which the flange 2 is suitably secured.

While only a single cylinder engine is here 11- lustrated, it is to be understood that any number of cylinders may be coupled together to provide a multi-cylinder motor but the showing and describing of a'single cylinder motor is suificient for a disclosure of the present invention.

The cylinder block has formed therein the cylinder 4 having the sloping or inclined head 5 in which is a suitable opening 6 for an igniter such as a spark plug 1. The upper part of the wall of the block is chambered to form a water jacket 8 and below this water jacket is an annular air chamber 9, the function of which will be hereinafter described. There is also formed in 40 the Cylinder block below the air chamber 9, a vertically extending short air by-pass passage II] which opens at its upper and lower ends-into the cylinder 4, but these ends of this passage are never" in communication with the cylinder above the piston, as will be hereinafter explaned.

The exterior surface of the cylinder head 5 is provided with aseries of upwardly extending fins l I and covering the fins and the head 5 is a cap 12 which has downwardly extending fins l3 which are disposed between the fins H of the cylinder head, thus cooperating with these latter fins to form baflles which provide a tortuous passage from a fuel inlet port M at one side of the cap l2 to the downwardly leading fuel tube 15 55 which is at the opposite side of the cap and which extends downwardly through the cylinder block between the cylinder and the water jacket as shown. The cap I2 is suitably secured as indicated at Hi, to a supporting flange encircling the cylinder block and the area. between the cap and the cylinder head 5 forms a fuel vaporizing or generating chamber.

The bottom or base block! of the engine is suitably formed to receive crank shaft bearings 18 which in turn receive the parts of a crank shaft [9 lying at opposite sides of the crank 20.. The central part of the base block 3 is chambered to form the crank case 2| into which the crank swings during its revolution.

One of the bearings I8 is provided with an annular oil channel 22 which opens against the crank shaft and the shaft together with the crank thereof is provided with the oil distributing channel 23 which leads from the annular groove 22 through the two arms and the central or yoke portion of the crank and terminates in the part of the shaft upon the remote side of the'crank from the channel 22, as indicated at 24. In the yoke portion of the crank a lateral outlet opening is formed which communicates with the iongitudinal passage 25 formed through the connecting rod 26 which at one end is coupled with the shaft crank in the manner illustrated.

Within the cylinder is the piston 21, the head 28 of which is inclined to correspond with the inclination of the cylinder head 5. The side of the piston at the high slde'of the head thereof is cut out' or formed to provide the air and fuel receiving pocket into which the air and fuel is discharged when the piston is at the low point of its movement and this pocket tends to deflect the charge upwardly into the cylinder so that it will not be carried across the cylinder to the exhaust port 30 which leads from the cylinder to the exhaust pipe ii;

The piston carries the usual wrist pin 22 by which the connecting rod 25 is coupled therewith and this wrist pin is provided with the longitudinal oil passage 33 which is joined to the passage 25 intermediate its ends, as shown, and which, in addition-to discharging through the ends of the wrist pin toward the cylinder wall, connects with upwardly discharging tubes 3 which are located within the upper part of the piston. By this means oil may be discharged. through the upper part of the piston to assist in keeping the piston temperature down.

Below the wrist pin the skirt portion of the piston is provided with the oppositely disposed

ports

35 and 36. The port 35 is designed to 8- ister with the air intake port 31 which is formed through the cylinder block and which is closed by the piston at all times except when the piston reaches the position where it registers with this port 35. The outer end of this inlet port is connected with a suitable air strainer 25 so that only dust-free air will be taken into the engine. I

The lower end-of the piston is closed by the bottom plate 39 and this is integral with a sleeve 40 whichextends up and over the'wrist pin so that the connecting rod will have free rocking movement in the lower part of the piston but the interior of the piston will remain closed except for the two ports 25 and 25 which open through the sides of the skirt portion and the laterally opening oil apertures? 4| which are located beneath the-ports 35-45 and pass between the lower piston rings.

Enclrcling the shaft I! at opposite sides of the crank and outwardly of the channels 22 and 24 there are formed in the base block and through the bearings theoil collecting chambers 42. These chambers at their lower ends have downwardly opening flap valves 43 and beneath the valves the chambers communicate with the drain passages or tubes 44 which are formed through the base block and are inclined downwardly to discharge into the crank case or chamber 2|.

The bottom of the crank case 2| has an air outlet 45 controlled by a downwardly opening flap valve or other suitable type of one-way valve 45. This discharge or outlet port. 45 is connected by a suitable pipe 41 with an inlet for an oil receptacle 48. This receptacle is formed to provide at one side a chamber 49 for a filtering unit 50, the chamber 49 being in communication with the interior of the receptacle through the port 5|. The oil receptacle is provided with a discharge pipe 52 which at one end opens into the receptacle and is con-" nected as shown by suitable swivel coupling 52 with a downwardly opening nozzle 54. The oil discharge pipe 52 is connected with the base block 3 and discharges through a suitable port 55 therein into the oil channel 22. The filling opening for the oil receptacle is closed by a suitable screw cap 55, as-shown.

The numeral 51 designates the fuel receptacle for the engine which may be gasoline or other suitable fluid fuel and this receptacle has connected therewith one end of an air pipe 53 which leads from the filter chamber 49 to the port 59 which is closed by an inwardly opening valve 60. Within the fuel receptacle 51 there is a stationary body 6| having a fuel outlet passage 52, one end of which opens into the receptacle while the other end communicates with the port 63 to which an end of a fuel conducting pipe 54 is connected. The body 6| constitutes a support for a swingably supported nozzle 65 which is joined with the body to open into the lower'end of the passage 62, by a swivel connection 53, such as was described in connection with the nozzle 54.- A filling opening for 5:168 fuel receptacle is closed by the threaded cap The fuel pipe 54 leads to and is connected at its other end in the inlet port l4 which discharges into the vaporizing chamber over the head of the engine cylinder and this pipe is provided with a suitable shut-oi! valve 61.

Extending into the fuel receptacle 51 is an end of an air conducting pipe 58 by which scavenging air, is carried from the upper part of the fuel receptacle to the air chamber 9 which is formed in the cylinder block, the other end of this air pipe 58 being connected with the cylinder block'to discharge into the air chamber in the manner shown in Fig. 1. Within the receptacle 51 the air pipe 58 is connected by a swivel coupling 53 with an upwardly directed air outlet nozzle 69. This nozzle is main tained with its open end directed upwardly in the fuel receptacle, by the provision of a weight 15 connected with the end thereof remote from the inlet end. a By this means the air outlet nozzle 69 will always be held in upright position so that only air may leave the receptacle 51 from above the,fuel therein whereas only fuel may leave wardly directed viding these swinging nozzles in the oil fuel outlet nozzle 65. By proand fuel the receptacle 'by way of the downtank, it will thus be seen that the engine is' particularly adaptable to use in airplanes or other locations where the engine would be tilted from vertical .position as the flow of oil and fuel will continue regardless of the angular position in which the engine is located. The crank shaft I9 is provided with the usual flywheel II and a distributor mechanism of standard construction may be employed for use in association with the firing plug 1 so as to time the firing of the plug with the movement of the piston 21. Such a distributor is indicated at 12 and has its operating shaft 13, Fig. 6, geared to the crank shaft l9 as is illustrated in detail in this figure, the distributor shaft and crank shaft gears being indicated respectively by the numerals 14 and I5.

Extending through the cylinder block and threaded in a suitable opening in the wall of the cylinder 4 at the level of the. lowest position assumed by the piston pocket 29 is a fuel mixer or carburetting device which is generally indicated by the numeral 16. This device comprises a casing 11 having two

longitudinal chambers

18 and 19 thereinand as shown in Fig. 4, the device extends through the air chamber 9. At its sage I5, as is shown in Fig. 1.

of the two valves the ste inner end the two

chambers

18 and 19 have valve seats 80 and 8i, respectively, which form-the peripheries of discharge openings directed into the cylinder. The chamber 18 has a lateral'opening 82 communicating with the air chamber 9, as shown in Fig. 4.

An air control valve 83 is disposed in the chamber 18 and at its outer end has screw threads 84 which are in threaded connection with the wall of the chamber so that'the point of this-valve, which is indicated at 85, may be advanced toward the seat 80 or retracted therefrom as desired to control the flow of air through the chamber 18 into the cylinder. The outer end of the air valve 83 has a stem 86'extending longitudinally therefrom, to which is attached a control arm 81.

The chamber 19 has communicating therewith an end of a fuel conducting pipe 88 which leads from and forms a continuation of .the fuel pasv Within the fuel chamber 19 of the mixing device is a needle valve 99, the forward end or point 90 ofwhich is designed to seat at 8| to close or restrict the fuel discharge aperture. Adjacent its rear end the needle valve 89 is screw threaded, as indicated at 9|, for threaded connection with the wall of the chamber 19 so that by rotating the needle valve its point may be advanced or re tracted as desired. The rear end of the needle valve has the stem 92 carrying an arm 93 and: this arm is coupled with the arm 81 of the air valve by means of a link 94, as shown in Fig. 5,;

or in any other suitable manner so that these valves may be rotated as a unit to control therichness of the fuel mixture. For the control mayhave the additional ar 95 connected therewith for connection with a suitable actuating rod or cable, not shown, by which the running of the engine may be controlled from any remote point.

86 of the air valve lower end of the air pipe 68 is shown in detail. As shown in this detail view, the end of the pipe to which the spout is attached is provided with a lateral flange 96 and the spout has a similar flange 91 which encircles the inner end of the passage of the spout and these flanges, both being of the same diameter, are brought into side by side relation and are held in this manner for relative rotary movement by the interiorly channeled annulus 98 which is placed in encircling relation with the flanges. It will be readily seen that while this annulus prevents the flanges from separating, it also permits them to rotate relatively upon their axial centers.

In the operation of the present two-cycle gasoline or internal combustion motor, the piston when raised will effect a reduction of pressure in the part of the cylinder lying beneath it and in the crank case or chamber 2|, resulting in the closing of the air bypass valve 46. After the cylinder reaches its maximum inward position, the port 35 in the skirt of the piston will register with the air inlet 31. Due to the reduced pressure established beneath the piston air will be forced in through the strainer 38 and 'will pass across the piston through the port 36,

into the passage l0 and into the cylinder beneath 1 the piston. On the downward stroke the air beneath the piston will be forced through the valve 46, through pipe 41, into the oil receptacle 48. The pressure established in this receptacle will force the oil through the pipe 52 to the lu-' and 34, respectively.

The air under pressure will also pass through the filter 50 and, by way of pipe 58, will enter the fuel receptacle 5'! through the valve controlled inlet port 59.. It will be apparent that after the piston has been reciprocated two or three times in the cylinder, both of the receptacles will have an air pressure established therein so that'the distribution of the oil in the manner described may take place and so that some of the fuel will be forcedfrom the fuel receptacle through the pipe 64 into the vaporizing or generating chambered head l2. At the starting of the motor, some of the fuel vapor will pass through the passage l5 to the carburetting device 16 and this will be mixed with air which will. be forced under pressure from the upper part of the fuel receptacle through the pipe 68 and into the air chamber 9 to the air discharge opening at the air valve seat 80. When the engine becomes heated, then the fuel entering beneath the head l2 will be more completely vaporized and this vapor will enter the carburetting device 'and'be discharged therefrom with the air into the cylinder by way of the piston pocket 29 when the piston is at its extreme outward position with respect to .the cylinder.

It will be readily apparent that in the operation of the motor, the air discharged into the cylinder will also function to scavenge the cylinder, removing the products of combustion of the previous charge by way of the outlet 30 which outlet is uncovered, of course, only when the piston is at its extreme outward position. Control of the speed ofthe motor is accomplished byv the oscillation of the lever 95. This operation of the lever effects the turning of the air and

fuel control valves

83 and 89 so as to increase or decrease the amount of air and'fuel which will be introduced into the cylinder.

By the provision of a hollow piston closed at its lower end and the passage of the air through the piston before it is introduced into the cylinder beneath the piston to be forced therefrom under compression into the oil and fuel receptacles, the cooling of the piston is accomplished. The piston temperature is also kept down by discharge of oil into the upper part thereof from the tubes 34.

By the provision of the oil apertures 41 in the skirt of the piston, the oil may be drained back into the crank case 2| and fromvhere it will be forced back into the oil receptacle upon the downstroke of the piston.

Any oil which may work outwardly along the crank shaft bearings will be caught in the oil pockets 42 and from these pockets it will be drawn back into the'crank casing 2| through the channels 44 by the reduced pressure established in the crank case on the upstroke of the piston. Loss of pressure on the downstroke of the piston through these passages H is prevented by the valves 43 which are at the outer ends of the oil passages.

From the foregoing, it will be readily apparent that there has here been disclosed a novel and improved form of two-cycle internal combustion engine wherein the number of moving parts is greatly reduced, the feeding of fuel and lubricant is positive at all times, the fuel is effectively vaporized for introduction into the cylinder and the entire system is kept closed so that all possibility of fuel and oil escaping and creating a fire hazard is eliminated.

What is claimed is:

1. An internal combustion engine of the character described, comprising a piston cylinder, a crank case closing the lower end of the'cylinder and opening thereinto, a crank shaft extending through the case and having a crank working therein, a piston reciprocable in the cylinder and operatively coupled with said crank, means for admitting air to the cylinder beneath the piston upon the upstroke of the piston, an air-tight fuel receptacle, means for conducting air compressed in the ducting fuel under pressure from the receptacle into the cylinder above the piston when the latter is at the outward limit of its movement, means for introducing air under pressure through the same inlet as and with the introduced fuel, and means for exhausting the cylinder of products of combustion when the piston is at said outward limit of its movement.

2. An internal combustion engine of the char- I acter described, comprising a piston cylinder,

means forming a crank case closing the lower end its outward movement, a pairof receptacles one.

adapted to contain lubricating oil and the other liquid fuel, said receptacles being connected in series relation with said crank case toreceive crank case by the downstroke' of the piston into the receptacle, means for concompressed. air therefrom, means for conducting oil from the oil receptacle to moving parts of the motor, a fuel inlet for the cylinder, means rotatable in said case and operatively coupled with the piston, means for admitting air to the cylinder beneath the piston when the latter is at the limit of its inward movement, the piston operating to compress the air in the crank case upon its outward movement, a pair of receptacles one adapted to contain lubricating oil and the other liquid fuel, said receptacles being connected in series relation with said crank case to receive compressed air therefrom, means for conducting oil from the oil receptacle to moving parts of the motor, a fuel inlet for the cylinder, means for conducting fuel from the fuel receptacle to said inlet, means for introducing air with the fuel through said fuel inlet, and an exhaust I port for the cylinder, said fuel inlet and exhaust ter is at the limit of its outward movement, the said air admitting means comprising a tubular connection between the air inlet port and the "upper part of the fuel receptacle whereby air under pressure may be transferred from the fuel receptacle to the fuel inlet port.

4. An internal combustion engine, a piston cylinder, a piston in the cylinder, a crank shaft operatively coupled with-the piston, said cylinder being closed beneath the piston whereby the piston may operate to establish pressure in the lower part of the cylinder upon its outward movement, a fuel receptacle, a fuel inlet port for the cylinder which is located to be uncovered by the piston when the latter is at the limit of. its outward movement, means for effecting the discharge of fuel from the receptacleto and through said fuel inlet port by the air compressed in the cylinder, means providing a fuel vaporizing chamber between the receptacle and the fuel port and heated by the cylinder, and an exhaust port for the cylinder, said exhaust port and fuel intake port being uncovered by the piston when the latter is at the limit of its outward movement.

5. An internal combustion engine, comprising a cylinder having a fuel inlet port through a side wall thereof, means forming a heated fuel vapor- 1 izing chamber over the head of the cylinder and communicating with said port, a fuel receptacle separate-from said chamber and having communlcation with said chamber for the transfer of ,fuel to the chamber, a piston in the cylinder, crank means operatively coupled with the piston, means closing the lowerpart of the cylinder whereby said piston operates for the compression of air therein uponits outward stroke, means for transmitting compressed air from the lower part of the cylinder to the fuel receptacle where it is retained under pressure, an exhaust port for the cylinder, and means for transmitting air held under pressure in the fuel receptacle from such receptacle tothe fuel inlet port, said exhaust port and fuel inlet port being uncovered by the piston when the latter is atthe limit of its oup ward movement in -the cylinder..

6. An internal emin lcomprising a cylinder having a fuel inlet port through a side wall thereof, means forming a heated fuel vaporizing chamber over the head of the cylinder and communicating with said port, a fuel receptacle having communication with said chamber for the discharge of fuel thereinto, a piston in the cylinder, crank means operatively coupled withthe piston, means closing the lower part of the cylinder whereby said piston operates for the compression of air therein upon its outward stroke, means for transmitting compressed air from the lower part of the cylinder to the fuel receptacle, an exhaust port for the cylinder, means for transmitting .air under pressure from the fuel receptacle to the fuel inlet port, said exhaust port and fuel inlet port being uncovered by the piston when the latter is at the limit of its outward movement in the cylinder, andmeans for admitting air to the cylinder beneath the piston which is controlled by the piston and functions when the piston is at the limit of its inward movement in the cylinder.

7. An internal combustion engine, comprising a cylinder having a fuel inlet port through a side wall thereof, means forming a heated fuel vaporizing chamber over the head of the cylinder and communicating with said port, a fuel recep-" tacle having communication with said chamber for the discharge of fuel thereinto, a piston in the cylinder, crank means operatively coupled with the piston, means closing the lower part of the cylinder whereby said piston operates for the compression of air therein upon its outward stroke, means for transmitting compressed air from the lower part of the cylinder to the fuel receptacle, an exhaust port for the cylinder,

' means for transmitting air under pressure from the fuel receptacle to the fuel discharge port, said exhaust port and fueldischarge port being uncovered by the piston when the latter is at the limit of its outward movement in the cylinder,

' said piston being of hollow construction and closed at its lower end and having a pair of ports through its skirt portion, an air inlet for the cylinder, which is registrable with one of said piston ports when the piston is at the limit of its inward movement in the'cylinder, and a bypass in the wall of the'cylinder having an end arranged to register with the other piston port when the piston is at the limit of its inward movement and having its other end discharging into the cylinder beneath the piston.

- 8. An internal combustion engine, comprising a cylinder block formed to have a piston cylinder therein, a chamber formed in the block, said cylinder having a solidhead, a cap secured over and in spaced relation with the head and forming therewith a fuel vaporizing chamber, a fuel mixing unit comprising a body having a pair of chambers thereineach opening through an end of the unit and adjustable valves in the body each/controlling a chamber opening, said unit being secured in the wall of the cylinder with said chamber openings directed into the cylinder, one of said unit chambers being in communication with said air chamber, the other of said unit chambers being in communication with said vaporizing chamber, an air-tight fuel receptacle, means for conducting fuel from the receptacle to said vaporizing chamber, a piston in the cylintherewith, said cylinder being closed beneath the piston and said piston operating to compress. air

in the lower part of the cylinder, upon the outward stroke of the piston, means for admitting for conducting air under pressure from the lower part of the cylinder into said fuel receptacle, an exhaust port for the cylinder, said exhaust port and mixing unit chamber openings being disposed in a plane to be uncovered by the piston when it is at the limit of its outward stroke, and means for introducing airinto said air chamber.

9. An internal combustion engine, comprising a cylinder block formed to have a piston cylinder therein, a chamber formed in the block, said cylinder having a solid head, a cap secured over and in spaced relation with the head and forming therewith a fuel vaporizing chamber, a fuel mixing unit comprising a body having a pair of chambers therein each opening through an endof the unit and adjustable valves in the body each controlling a chamber opening, said unit being secured in the wall of the cylinder with said chamber openings directed into the cylinder, one of said unit chambers being incommunication with said air chamber, the other of said unit chambers being in, communication with said vaporizing chamber, an air-tight fuel receptacle, means for conducting fuel from the receptacle to said vaporizing chamber, a piston in the cylinder having a crank shaft operatively connected therewith, said cylinder being closed beneath the piston and said piston operating to compress air in the lower part of the cylinder upon the outward stroke of the piston, means for admitting air into the lower part of the cylinder when the piston is at the limit of its inward stroke, means for conducting air under pressure from the lower part of the cylinder into said fuel receptacle, an exhaust port for the cylinder, said exhaust port and mixing unit chamber openings being disposed in a plane to be uncovered by the piston when it is at the limit of its outward stroke, and air conducting means connecting said air chamber with the upper part of the fuel receptacle for the transmission of air under pres- .Sure from the receptacle to the air chamber.

10; An internal combustion engine, comprising a piston cylinder, a piston in the cylinder, the

- lower part of the cylinder being closed, a crank shaft operatively coupledwi-th the piston, the piston being designed to compress air on its outward stroke in ,the lower part of the cylinder, a fuel mixing unit comprising a body having a pair of chambers therein each opening through a wall of the body, the body being secured in a wall of the cylinder with said chamber openings directed into the cylinder, said unit in'cluding a valve in each of said chambers which is movable relative to the chamber opening for regulating the size of the same, an air-tight fuel receptacle, an air line connecting the lower part of the cylinder with said receptacle, a fuel conducting line leading from the lower part of the fuel receptacle to. one of the chambers of said unit, anair conducting line leading from the upper part of said receptacle to the other chamber of said unit, and an exhaust port for the cylinder, said latter port and theunit chamber openings being uncovered by the piston when the same is at the limit of its outward movement in thecylinder.

11. An internal combustion engine, comprising a piston cylinder, a piston in the cylinder, the lower part of the cylinder being closed, a crank shaft operatively coupled with the piston, the

piston beingdesigned to compress air on its outward stroke in the lower part of the cylinder, a fuel mixing unit comprising a bodyhaving a 30 the body, the body being secured in a wall of the pair of chambers therein each opening through a wall of the body, the body being secured in a wall of the cylinder with said chamber openings directed into the cylinder, said unit including a valve in each of said chambers which is movable relative to the chamber opening for regulating the size of the same, an air-tight fuel receptacle, an air line connecting the lower part of the cylinder with said receptacle, a fuel conducting line leading from the lower part of the fuel receptacle to one of thechambers of said unit, an air conducting llne leading from the upper part of said receptacle 'to the other chamber of said unit, an exhaust port for the cylinder, said latter port and the unit chamber openings being uncovered by the piston when the same is at the limit of its outward movement in thecylinder, and means within said receptacle and connected with said fuel conducting and air conducting lines for maintaining the inlet ends of said lines constantly in communication with the upper and lower portions of the fuel receptacle.

l2. An internal combustion engine, comprising a piston cylinder, a piston in the cylinder, the

lower part of the cylinder being closed, a crank' shaft operatively coupled with the piston, the piston being designed to compress air on its outward stroke in the lower part of the cylinder, a fuel mixing unit comprising a body having a pair of chambers therein each opening through a wall of cylinder with said chamber openings directed into the cylinder, said unit including a valve in each of said chambers which is movable relative to the chamber opening for regulating the size of the same, an air-tight fuel recepatcle, an air line connecting the lower part of the cylinder with said receptacle, a fuel conducting line leading from the lower part of the fuel receptacle to one of the chambers of said unit, an air conducting line leading from the upper part of said receptacle to the'other chamber of said unit, an exhaust port for the cylinder, said latter port and the unitchamber openings being uncovered by the piston when the same is at the limit'of its outward movement in the cylinder, and a pair of inlet nozzles in said fuel receptacle each swivelly supported and. connected with one of said lines, 'said nozzles'being so constructed and arranged that the nonle connected with the fuel line will have its inlet end constantly immersed in the fuel of the, receptacle and the nozzle connected with the air conducting line will have its inlet end constantly maintained in the upper part of the receptacle above the fuel level.

13. Anengine structure, comprising a cylinder having a head, a piston within the cylinder, a crank shaft operatively coupled with the piston, means closing the lower part of the'cylinder'and forming a compressed air chamber in which a portion of the crankshaft operates, said piston being closed at its lower end, means for admitting air to the cylinder beneath the piston when the latter is at the limit of its inward movement in the cylinder, means lying above the cylinder head' forming a fuelvaporization chamber, said chamber being heated from the cylinder head, an airtight liquid fuel receptacle, means'for conducting air from said crank case to said receptacle, means for conducting fuel under air pressure from the receptacle to said vaporization chamber, means for discharging vaporized fuel from said chamber into the cylinder, means for conducting air under pressure from the fuel receptacle into the cylinder at'a level adjacent the top of the piston when the latter is at the limit oi. its outward movement, and an exhaust port for the cylinder which is uncovered by the piston when the latter is at the limit of its outward movement.

it. An-internal combustion engine, comprising a cylinder having inlet and exhaust ports, an airtight fuel receptacle. a piston in the cylinder and a crankshaft coupled with the piston, means for admitting air to the cylinder beneath the piston when the latter is at the limit of its inward movement to be compressed by the piston on its outward movement, means for transferring air under pressure from beneath the piston into said receptacle, an air and fuel controlling valve unit secured in said inlet port, a fuel conduitleading from the lower part of thereceptacle tosaid unit, an air conduit leading from the upper part of the receptacle to said unit, and said inlet port being uncovered by the piston when the same is at the outward limit of its movement for admission of air and fuel into the cylinder through the valve unit and inlet port.

15. An internal combustion engine, comprising a cylinder having inlet and exhaust ports, an air-tight fuel receptacle, a piston in the cylinder and a crank shaft coupled with the piston, means for admitting air to the cylinder beneath the piston when the latter is at the limit of its inward movement to be compressed by the piston on its outward movement, means for transferring air under pressure from beneath the piston into said receptacle, an air and fuel controlling valve unit secured in said inlet port, a fuel conduit leading from the lower part of the receptacle to said unit, an air conduit leading from the upper part of the receptacle to said unit, said inlet port bein uncovered by the piston when thesame is a the outward limit of its movement for admission of air and fuel into the cylinder through the valve unit and inlet port,

and pivoted gravity controlled inlet nozzles con-.

nected within the receptacle with the fuel conduit and the air conduit and the fuel conduit connected nozzle maintaining its open end in the lower part of the receptacle and the air conduit connected nozzle maintaining its open end in the upper part of the receptacle above the fuel level.

16. An internalcombustion engine, comprising a cylinder having inlet and exhaust ports, an air-tight fuel receptacle, a piston in the cylinder and a crank shaft coupled with the piston, means for admitting'air to the cylinder beneath the piston when the latter is at the limit of its inward movement to be compressed by the piston on its outward movement, means for transferring air under pressure from beneath the piston into said receptacle, an air and fuel controlling valve unit secured in said inlet port, a fuel conduit leading from the lower part of the receptacle to said unit, an air conduit leading from the-upper part of the receptacle to said unit. said inlet port being uncovered by the piston when the. same is at the outward limit of its movement for admission of air and fuel into the cylinder through the valve unit and inlet port, said valve unit having two chambers each chamber having an inlet and an outlet, the outlets being directed through the cylinder inlet port, one valve inlet receiving air and the other valve inlet receiving fuel, and means in each valve chamber which is adjustable relative to the outlet thereof for controlling the same.

17. In an internal combustion engine having a cylinder provided with inlet and exhaust ports, 1|

a piston in the cylinder and a crank shaft operatively coupled with the piston, the inlet port opening into the cylinder at a level to be uncovered by the piston when the piston is at the limit of its outward movement, an air-tight liquid fuel receptacle, a fuel conduit leading from said receptacle to said inlet port, an air conduit.

leading from said receptacle to said inlet port, means for introducing air under pressure into said receptacle for intermittent discharge therefrom through the air conduit to the inlet and for forcing fuel therefrom through the fuel conduit to the inlet, and pivoted gravity controlled inlet nozzles within said receptacle connected.

with the fuel conduitand the air conduit, the nozzle connected with the fuel conduit being constantly maintained with its inlet end directed downwardly into the fuel in the receptacle and the nozzle connected with the air conduit bein constantly maintained with its inlet end directed upwardly in the receptacle above the fuel level therein.

18. An internal combustion engine, comprising 'a cylinder having inlet and exhaust ports, a piston in the cylinder and a crank shaft operatively coupled with the piston, the cylinder wall having an air chamber therein, a cap secured over the top of and having a portion spaced-from the head of the cylinder and forming therewith a fuel vaporizing chamber having communication with said inlet, said inlet opening into the cylinder at a level to be uncovered by the piston when the latter is at the limit of its outward movement, an air-tight fuel receptacle, anv air conduit leading from the upper part of the fuel receptacle to said air chamber, a fuel conduit leading from the lower part of the fuel receptacle to said vaporizing chamber, and air compressing means connected with said fuel recep tacle for introducing air under pressure thereinto,,the inlet serving as a common point of entrance into the cylinder for the fuel and air under pressure.

BERNARD A. SWANSON.