US2494742A

US2494742A - Engine construction and cooling method

Info

Publication number: US2494742A
Application number: US728504A
Authority: US
Inventors: Gilbert E Buske
Original assignee: NAT PRESSURE COOKER CO
Current assignee: NAT PRESSURE COOKER CO; NATIONAL PRESSURE COOKER Co
Priority date: 1947-02-14
Filing date: 1947-02-14
Publication date: 1950-01-17
Anticipated expiration: 1967-01-17

Description

Jan. 17, 1950 G. E. BUSKE 7 2,494,742

ENGINE cousmuc'rxon Ann coounc mimon Filed Feb. 14, 1947 s Sheets-Sheet 1 X- 52 I a 54 .1

W [Avail/ K JWENToR. GILBERT E. B-USKE Jan. 17, 1950 N G. E, BUSKE 2,494,742

ENGINE CONSTRUCTION AND COOLING METHOD' Filed Feb. 14, 1947 z Sheet s-Shet 2 as 0 89 19 0 so '5 w s9 5: 6| 5a n .11 (an as.

O as

,vs 77 k V 15 89 Z 84 as 4 u a4 4 N Jan. I7 1950 s. E. BUSKE 2,494,742

ENGINE cons'mucuon m coounc names Filed Feb. 14, 1947 a Sheets-51199126 no u /Enron.

QILBERTEYBUSKE Patented Jan. 17, 1950 ENGINE CONSTRUCTION AND COOLING METHOD Gilbert E. Buske, Anson Township, Chippewa County, Wis, asaignor to National Pressure Cooker Company, Eau Claire, Wis, a corporation of Wisconsin Application February 14, 1947, Serial No. 728,504

This invention relates to internal combustion engines such as are usedin outboard motor units,

and has to do with the construction of such an engine and the means for and method of cooling it Outboard motors are ordinarily water cooled and the cooling water preferably is circulated by a constant displacement type pump, 1. e., a pump -whi ch displaces a substantially constant volume of water per stroke, driven by the engine. It is common practice to supply the cooling water from the pump directly to the cylinder water jacket, or to the water jacket or cooling water space of the cylinder head With, the water passing through the two spaces either in series or in parallel and thereafter passing around the exhaust gas passage, so as to cool the exhaust gases and aid in their condensation, reducing their volume. In such an arrangement, particularly when the unit is used in cold water and the engine is'operated at low speed, over-cooling of the engine occurs. "That causes condensation of the water content of the combustion gaseson the cylinder sleevw; and heads of the engine, resulting in rusting of the cylinder sleeves and piston 16 Claims. Cl. 123-473) ingobjectionable cooling of the cylinder walls at low engine speeds. Also, the cooling water space extending across the cylinder head receives water from the cylinder water jacket in such manner that the amount of water supplied to that space varies directly as the speed of the engine. Consequently, when the engine is operating at the higher speeds, with corresponding increase in heat generated, the amount of water supplied to the water space of the head is increased sufiiciently to preclude overheating, without over-cooling. On the other hand, when the engine is operating at low speed, the supply of water to the cooling water space of the engine head is reduced to such an extent as to preclude over-cooling, while being suflicient to prevent overheating. In that manner, the temperature of the engine is controlled automatically in accordance with its speed of operation, and effective cooling, without over-cooling,-at all speeds is assured. Further objects and advantages of my invention will appear from the detail description.

rings and fouling of the spark plugs, which is objectionable for obvious reasons. Also, condensation of the entering fuel-air mixture'may occur, with-resultant loss in operating eiliciency of the engine, likewise objectionable for obvious reasons. 1 When the engine is operated at higher speeds, thesurfaces thereof in contact with the combustion gases and the. fuel-air charge drawninto the cylinders are heated to a temperature above the dew point of such gases and objectionable condensation may not then occur. It'will be seen that over-cooling and objectionable condensation are apt to be encountered when the engine is operated at low speed, as when trolling, for example.

My invention is directed to an internal combustion engine of simple and inexpensive construction and light weight, suitable for production by die casting and particularly suited to outboard motor units, which avoids the objections to present day engines in respect to over-cooling at low speeds, above referred to. The engine of my invention embodies a novel cooling system and method, such that adequate cooling is assured at all speeds and over-cooling, with resultant objectionable condensation at low speeds is prevented. More specifically, I provide means In the drawings: V

Figure 1 is an isometric side view of an outboard motor unit embodying the engine of my invention;

Figure 2 is an end view of the engine of the unit of Figure 1, with the cylinder head cover plate partly broken away, certain other parts being broken away and the engine accessories, including the spark plugs, being omitted for clearness of illustration;

Figure 3 is an underneath view of the'engine;

Figure 4 is a fragmentary sectional view, on an enlarged scale, taken substantially on line 4-4 of Figure 3;

Figure 5 is a fragmentary sectional view, on an enlarged scale, taken substantially on line 55 of Figure 3;

Figure 6 is a fragmentary transverse vertical sectional view, on an enlarged scale, of the top substantially on line of Figure 7, on an being broken away;

Figure 13 is a sectional view taken substantially on line |3'|3 of Figure 2, certain parts being shown in elevation and certain other parts being broken away;

Figure 14 is a sectional view taken substantially on line |4-|4 of Figure 13;

Figure 15 is a sectional view taken substantially on line ||5 of Figure 13; and

Figure 16 is an isometric view of the intermediate and lower sections and associated parts, of the outboard unit on an enlarged scale, with certain parts broken away and shown in section.

I have illustrated my invention, by way of example, as embodied in an outboard motor unit utilizing a two cylinder, two cycle internal combustion engine of the horizontal type, i. e., an engine mounted with the cylinders thereof disposed horizontally, as is usual in outboard motor units. It is to be understood, however, that my invention is also applicable to engines having one or any suitable number of cylinders and, in its broader aspects, to vertical cylinder engines, and that the terms, horizontal, upper, lower and side, as used in this specification and the appended claims, with reference to a horizontal engine, are used for convenience of description and are to be so construed and not in a limiting sense as to the substance of my invention.

The outboard motor unit 2t shown in Figure 1 comprises an underwater section 2|, an intermediate section 22, and an upper section comprising a motor support tube 23 having a flanged fitting 24 fixed to its lower end. The sections 2| and 22 are secured together and to fitting 24 in a suitable manner, convenientlyv by bolting, as is known; A hearing sleeve 25, formed of two sections bolted together, fits about the support tube 23, between a mounting plate 26 fixed on the upper end of the tube 23 and the fitting 24, there being a washer 21 between the lowerend of sleeve 25 and the upper end of fitting 24. An arm 28,

rigid with the upper end of sleeve 25, carries a clamp bracket 29 suitably mounted thereon, by means of which the unit may be secured to the stern sill or transom of a boat. When the unit is mounted on a boat, the sleeve 25 supports tube 23 and the parts carried thereby for turning movement about the axis of the tube.

The mounting plate 26 is of dished formation, open at its top, where it is provided with an outwardly extending peripheral flange 30, and is of substantial depth interiorly opening directly into the upper end of motor support tube 23. Flange 30 is of generally elliptical shape in plan'and has its upper surface machined to provide a seating surface 3| of generally elliptical shape, as is shown more clearly in Figure 14. At its under face, mounting plate 26 is provided with down wardly opening recesses (Figure 13) carrying elements 32 cooperating with elements 33 carried by 'a flange 34 at the upper end of sleeve 25. The

elements

32 and 33 are included in steering stabilizing means for holdin tube 23 in desired adjustment about its axis. The stabilizing means referred to is not included in my instant invention and need not be further described here.

The lower section 2 l of unit 20 is provided with the usual skeg 35 (Figure 1) extending downward therefrom. This section 2| houses the gearing and associated parts for driving the propeller shaft, mounted therein, from a drive shaft 35 (Figure 13) extending from the power head downward through motor support tube 23 and the intermediate section 22. The propeller shaft (not shown) is rotatably mounted in section 2|, projects outwardly therebeyond, and has suitably mounted thereon a propeller 31. Section 2| also carries a constant volume water pump 33,

of suitable known type, having an underwater intake 39 opening through one side of section 2|.

A discharge passage 4|) leads from the discharge of pump 38 and opens into the lower end-of a bore 4| extending through the upper end of section 2|. A water supply tube 42, preferably formed of aluminum, fits snugly at its lower end in bore 4|] and extends upward therefrom through intermediate section 22 and support tube 23, alongside the drive shaft 35. The upper end of tube 42 communicates with the water'spaces of the engine of the power head for supplying cooling water thereto, as will appear more fully presently. I The intermediate. section 22 of unit 20 flares downward and is provided, at the stern thereof, with an underwater discharge opening 43 of substantial size, adjacent anti-cavitation plates 44 at the lower endand opposite sides of section 22.

The mounting plate 25 carries the power head, including the engine and its accessories. Since my instant invention has to do particularly with the engine, so far as the power head is concerned, in the accompanying drawings, I have omitted the engine accessories as well as certain parts of the engine itself not necessary to a disclosure of my invention, for clearness of illustration. The engine 45 is shown as a two cycle two cylinder engine, with its cylinders disposed horizontally. It comprises a substantially cubiform cylinder block 46 having at one end a vertically disposed crank case section 41 (Figure 12) integral therewith, and provided with two superposed horizontal cylinders 48, with cast in liners or sleeves 49 of cast iron, extending outward from its other end. The outer ends of the cylinders 43 are closed by a cylinder head 50 comprising an outer end wall structure 5| providing two connected cupped head members 52 (Figure 13) seating on the outer ends of cylinders 45 in sealing engagement therewith, with an intervening sealing gasket 53. The head 50 is provided with a peripheral wall or flange 54 connected to the end wall structure 5| by a web element 55 (Figure 2) having, adjacent flange 54, top and bottom slot-like openings or

ports

55 and 51, respectively.

The fiange'54 (Figures 12 and 13) extends out-- ward a short distance beyond the end wall structure 5| and receives, at its outer end, a fiat cover plate 58 seating thereon with an intervening sealing gasket 59. The plate 55 is shaped conformably to the cylinder head I. (Figure 2) which. in outer end view, approximates a figure-8 shape, and is provided with spaced outwardly extending bolting ears 5. disposed for alignment with spaced bolting bosses 5| integral with flange 54. Each head 52 is provided with an off center outwardly extending boss 62, the outer end of which is in the plane of the outer end of flange 54. The boss 52 is suitably bored and tapped to receive the reduced neck of a spark plug 53 passing through plate 58 and screwing into boss 52, between which and the inner face of plate 53 there is interposed a sealing gasket 64 disposed about the neck of the spark plug. A sealing gasket 05 is also provided about the neck of each spark plug 83, between the body thereof and the outer face of the cylinder head cover plate 58. I thus effectively guard against possible leakage, either interiorly or exteriorly of the cylinder head, about the spark plugs, and the latter may also function as supplementary means for securing the plate 58 in position should looseness develop in the main securing means, to be referred to presently. The cover plate 58 is spaced, by flange 54, outward a short distance from the end wall structure (Figures 12 and 13) and defines therewith and with flange 54 a cooling water space 66 extending across the cylinder head members 52.

The outer end of the body portion of cylinder block 46 extends outward beyond the cylinders 48 radially thereof and is machined off to provide a seating surface. Flange 54 extends from the end wall structure 5| inward along the cylinders 48 for a considerable distance, such that it seats on the seating surface of the outer end of the body portion of the cylinder block 48, with an intervening sealing gasket 61. Through bolts 88, having heads 59 at their Outer ends, pass through ears 68 of cover plate 58 and the tubular bosses 5| of flange 54, and screw into the outer end of the body of cylinder block 45, appropriately bored and tapped for that purpose. Spring washers 18 are interposed between cover plate 58 and the heads 69 of certain of the bolts 58, certain others of which may pass also through a flange H of a shield 12, disposed at the outer face of plate 58 and extending about the upper one of the spark plugs 63. It will be seen that the bolts 58 secure cylinder head 58 in position seated on cylinder block 45 in sealing engagement therewith, and secure the cover plate 58 tightly seated on the outer end of the cylinder head flange 54, these bolts 88 constituting the main securing means, previously referred to, for the cylinder head assembly. When the cylinder head 58 is secured in position on the cylinder block 48, flange 54 is spaced outward from cylinders 48 radially thereof defining therewith a cooling water space or jacket 13 extending about the cylinders and opening freely into head space 66 -through the upper slot or port 58 in web element 55, as will be explained more fully later.

The cylinder block is provided, in one side thereof, with a recess 14 (Figures '1 and 12) of generally oblong shape in side View, extending to some extent about the cylinders 48 and, at its inner end. about the crank case section 41. A thickened wall 15 frames the outer opening of recess 14 and projects a short distance outward beyond the body portion of cylinder block 46. Wall 15, like recess 14, has its longer axis disposed vertically and is of channel cross section at its top and its ends. A cross web 16, at the midlength of the top element of wall 15, separates the latter interiorly into an outer channel 11 and an inner channel 18 (Figure 10) adjacent crank case section 41. A suitable number of openings 19 (Figures 6 and 7)one or more-are bored in the cylinder block 45, from the upper end of outer channel 11, adjacent across web 18, into a water inlet passage 80 (Figures 6 and 13) formed in cylinder block 48 at the top thereof. The passage 88 flares toward, and opens through, the outer end'of the body portion of cylinder block 48 into the cylinder water jacket 13, at the top thereof, as shown in Figure 13. The passage 88 and openings 19 .8 I establish free communication between the cylinder water jacket 18 and the outer channel 11 of wall 15, as will be clear from what has been said.

The outer face of wall 15 is fiat and is machined to provide a seating surface. A cover structure 8I (Figures 7, 8, 9, and 12) is suitably secured, conveniently by screws 82, to wall 15 and seats thereon, with an intervening gasket 88 providing a water tight seal therebe'tween. The cover structure 8| comprises an inner flat closure plate 84 and an outer cover plate 85 of dished formation seating on plate 84. with an intervening gasket 88 providing a water tight seal therebetween. The screws 82 pass through appropriately disposed bosses of plate 85 and through plate 84, and thread into bosses of wall 15, as will readily be understood. The

plates

84 and 85 define between them a water space 81. Plate 84 is provided, adjacent its bottom, at its outer end, with an opening 88 which overlies the lower end portion of channel 11 of wall 15, and, adjacent its top, with an opening 88a which overlies the top portion oi channel 11, gasket 83 also being provided with openings in register with

openings

88 and 88a, respectively. Plate 84 is also provided, at its top, with an opening 89 overlying and opening into the top portion of channel 18 of wall 15, through an opening in gasket 83 in register with opening 89. The cover plate 85 is appropriately formed interiorly, as will be clear from Figures 8 and 11, to provide free communication between water space 81 and channels 11 and 18, through

openings

88 and 88a and opening 89 of closure plate 84. It will be clear, from what has been said, that water space 81 of cover structure 8| opens into channel 11 at the bottom and the top thereof and into channel 18 at the top thereof.

The crank case section 41 is provided, at its upper end, with a semi-cylindrical boss 98 (Figures 2, 7, and 13) and, at its lower end, with a second'semi-cylindrical boss 9i. An outer crank case section 92 is bolted to crank case section 41 and is provided, at its upper and lower ends with semi-cylindrical bosses 93 and 94, respectively. The bosses 93 and 94 are complementary to bosses 98 and 9I and define therewith collars receiving bearing bushings 95 and 96 in which a 0 vertical crank shaft 91 is rotatably mounted. An

oil seal 98, of known type, is disposed about crank shaft 91, at the upper end of bushing 95. A center main bearing ring I88 is suitably mounted in the crank case, centrally thereof, and fits snugly in a corresponding groove in the crank shaft 91, with the shoulder at the upper side of the groove seating on ring I88, which carries the load of the crank shaft. The ring I88 and its mounting separate the crank case interiorly into two separate chambers or compartments I8I into which the cylinders 48 respectively open, at their inner ends. The seal provided by the ring I88 and the cooperating shoulder of the crank case 91 is of importance. Since crank case compression is utilized to charge the combustion spaces of the cylinders 48, one compartment I8I of the cylinder is under pressure while the other compartment is under partial vacuum. Under such conditions, objectionable leakage between the two compartments will occur unless carefully guarded against. The seal provided by the shoulder of crank shaft 91 seating on the upper face of bearing ring I88 effectively prevents any objectionable leakage between the crank case compartments I81.

The outer crank case section 92 is provided, at its outer side, with an appropriately disposed and formed pad I02 (Figures 3 and 12) having therein passages I03 respectively opening into the compartments IOI. Each of the passages is controlled by an outwardly opening and inwardly closing poppet valve I04. An intake passage and spring housing member I05 is bolted to pad I02, at the outer face thereof, with an intervening gasket I06. Member I05 is provided with pockets I01, which receive compression springs I08 urging the valves I04 closed, and with a neck I09 having an intake passage IIO opening into the spring pockets I01, which overlie and open directly into the respective valve pockets III of pad I02. The outer end of neck I09 is adapted to bolting thereto a stack of a carburetor (not shown). The valves I04 are actuated in opening direction by cam followers I I2 pivotally mounted in the crank case and operated by appropriately disposed cams II3 on the cam shaft 91. The provision of means for admitting the combustible fuel mixture directly to the crank case compartment, or compartments, has an important bearing on the disposition of the exhaust gas recess 14, as will appear more fully presently. Within the broader aspects of my present invention, any suitable means may be provided for admitting the combustible fuel mixture directly into the crank case.

The cylinder -block 46 has formed therein, at the opposite side thereof from recess 14, two transfer passages IE4 (Figure 12) flaring toward and respectively opening at one end into the crank case compartments IOI. Passages II4 open at their other ends into hollow rectangular bosses II5 formed integral with block 46. The outer faces of bosses II5 are flat and formed to provide seating surfaces on which closure plates II6 seat, with intervening gaskets H1. The plates II6 are secured to bosses II'I in a suitable manner, conveniently by screws H8, and effectively close the outer sides thereof. Inlet ports I I9 are bored through the walls of the respective cylinders 48, to which ready access is had through the bosses I I5, these ports II9 opening directly into'the transfer passages II4, as will be clear. Also, exhaust ports I20 are bored through the walls of cylinders 48, at the opposite side thereof from inlet ports H9 and somewhat nearer the outer ends of the cylinders than inlet ports H9. The recess 14 in the cylinder block 46 gives ready access to the cylinders 48 for boring the exhaust ports I20 therein, as will be clear. Pistons I21 operate in cylinders 48 and have operating connection, by means of connecting rods" I22, to'the crank shaft 91. Each piston is provided, at its outer or head end, with an appropriately formed extension I23 for deflecting the entering fuel-air mixture charge toward the outer end of the cylinder and causing displacement therefrom of the burned gases to and through the exhaust outlet.

The provision of means for admitting the combustible fuel-air mixture charge directly to the crank case compartments renders it possible to have the water inlet passage 80 at the top of cylinder block 46, with the transfer passages H4 and the recess 14 at opposite sides thereof. The recess 14 may thus be disposed to best advantage, with the exhaust ports I20 opening directly into its outer end. Further, the recess 14 may have an outlet opening 524 of ample size, directly through the bottom of cylinder block 46 and its associated crank case section 41, disposed within the area enclosed by a seating surface I25 (Figure 3), formed on the bottom of cylinder block 46 and crank case section 41, conforming to the seating surface of the rearward or stem portion of flange 30 of mounting plate 26. The cylinder block 46 is also provided, at the bottom thereof and within seating surface I25, with a downwardly opening hollow rectangular boss I26 (F 8- ures 3, 14 and 15) from which a water outlet passage I21, extending outward along the under side or bottom\ of block 46, opens through the outer end of block 46 at the bottom of the cylinder water jacket 13. The bottom of boss I26 provides a seating surface I28 flush with and supplementary to seating surface I25, and the bottom of crank case section 92 is provided with a seating surface I29 constituting a continuation of seating surface I25 and conforming to the seating surface of the forward portion of flange 30 of mounting plate 26. The engine block and crank case assembly is thus provided, at the bottom thereof, with a seating surface, comprising the surfaces I25 and I29, conforming to, and adapted to seat accurately upon, the upper face of flange 30.

The lower cylinder 48 is provided, adjacent its bottom or under side, with two exterior lengthwise ribs 48a (Figures 2, 4, and 13), disposed at opposite sides of the bottom port 51 of head 5I. The ribs 48a extend from web element 55 of head 5| to the outer end of cylinder block 46, defining between them a water outlet passage or channel 121a leading from port 51 to the outer end of passage I21. Ribs 48a also extend radially outward from sleeve 48 to within a short distance of skirt or flange 54 of cylinder head 5|, defining therewith slot-like openings I21b providing restricted communication between the cylinder water jacket 13 and channel I21a.

The bearing sleeve at the bottom of the crank case, comprising the bosses 9I and 94, is provided with a downwardly opening annular channel I26. A plate I3I seats on the bottom of the bosses 5| and 94, with an intervening gasket I32, to which it is suitably secured, conveniently by screws I33 threading into suitably disposed bosses, and closes the bottom of channel I30. The plate I3I is provided with a rounded extension I34 (Figure 14) underlying a rounded projection 9Ia of boss 3|, and with a depending cylindrical neck I35. A tube I36 is secured, at its upper end, in neck I35 and extends therefrom downward. When the engine is mounted on plate 26, tube I36 extends downward about drive shaft 36, the upper end of which is splined to the lower end of crank shaft 91 (Figure 13), into the upper portion of motor support tube 23, in concentric spaced relation thereto and to shaft 36. A recess I31 is formed in an extension 15a of wall 15 (Figure 3) and opens into the lower end of channel 16 and into the annular channel I30, establishing communication therebetween. The outer side of recess I21 is closed by extension 92a of crank case section 92.

The mounting plate 26 is provided, at the after or stern portion thereof with an upwardly opening hollow boss I38 (Figures 13, 14, and 15) substantially rectangular in plan, the top of which is flush with the upper face of flange 30 and provides a seating surface I38a supplementary thereto. The forward or inner end wall I39 of boss 138 is provided with a water outlet aperture I46 of substantial size opening into mounting plate 26.

.As will be clear from Figures 3, 13, 14, and 15,

seating surfaces I25, I26 and I26, at the bottom will be clear,

9 of the cylinder block and crank case assembly, provide a continuous seating surface area which conforms to the seating surface area of flange 38 of mounting plate 26 and the top of boss I38. The cylinder block and crank case assembly. is suitably bored and tapped, in the area of the seating surfaces I25 and I29 thereof, for reception of headed screws I44 passing through flange 38 of plate 26, there being spring lock washers I45 interposed between the heads of screws I44 and the underface of flange 38. The engine may thus be mounted upon the mounting plate 26 with expedition and facility, with a sealing gasket I46 disposed between the seating surfaces thereof. Gasket I46 may be provided with an extension conforming to the opposed seating surfaces of the bosses I26 and I38, disposed therebetween.

The projection 9Ia of boss 8| a stepped bore 8Ib, of larger diameter at its lower end portion, extending from its under face and opening into channel I38. A backing washer I (Figure 13), which may be formed of brass or other suitable metal, seats in the lower portion of bore 8Ib, and a sealing washer I42 also seats in the lower portion of bore 8|b and is confined between washer MI and extension I34 of plate Ill. The extension I34 of platei|3| is provided with an aperture which registers with the lower end of bore 8Ib. The upper end portion of water tube 42 is straight lengthwise and is offset outward a shortdistance from the body portion thereof, to which it is connected by a short curve or bend, as shown. The sealing washer I42 preferably is formed of a synthetic rubber, such as "neoprene," and is of an inner diameter to flt tightly about tube 42 in sealing contact therewith. In mounting the engine on the mounting plate 26, the straight upper end portion of tube 42 is inserted through the washers I42 and I, the inner diameter of washer I being slightly greater than the outer diameter of tube 42, as will be understood. To assist in inserting tube 42 through the washers I42 and I, the upper end of tube 42 is cut on a slant, as shown. It from what has been said, that when the engine is mounted on plate 26 and is in operation, water will be delivered from the discharge of pump 38 through tube 42, under pressure to channel I38. By removing the screws I the engine and the parts carried thereby, constituting therewith the power head, may be lifted as a unit from the mounting plate 26. The water supply tube 42 may then readily be withdrawn through the motor support tube 23, for inspection, cleaning, repair or replacement.

The wall and the cover structure 8| mounted thereon define, with recess 14 of cylinder block 46, an expansion chamber, of adequate volume, for the exhaust gases discharged from the cylinders 48 directly into that chamber through the exhaust ports I28. When the engine is mounted on plate 26, the exhaust expansion chamber opens directly into that plate, through opening I24, as will be clear, and tube I36 extends downward about drive shaft 36 into the upper portion of motor support tube 23, in concentric spaced relation to both thereof.

is provided with substantial extent by heat .before passing to the cylinder water jacket, which ward about the In the operation of the engine, when the unit is in use, the pump 38 delivers water under appropriate pressure to the water supply tube 42. The water is discharged from tube 42 into channel I30 (Figures 3 and 13), where it eifectively cools the lower crank shaft bearing so as to prevent overheating thereof. From channel I30 the water flows through recess In (Figure 3) into channel 10 18 and upward through the latter channel and opening 88 of closure plate 84 (Figure 7) into water space 81 (Figures 10 and 11) of the exhaust expansion chamber cover structure 8|. It will be noted that the cover structure is of a height equal to that of the cylinder block 46 and of a length approximating thatof cylinder block 46 (Figures 7 and 13), being of substantial extent in a plane paralleling the cylinder axes, while the water space 81 of cover structure 8| (Figure 12) is of but slight thickness or extent perpendicular to that plane. Accordingly, the water entering space 81 is spread out therein in a thin layer or sheet of considerable extent, and is there subjected to the heat of the hot exhaust gases discharged into chamber 14. the cover structure 8| is thus heated to a substantial extent by the exhaust gases and quickly cools and condenses such gases, substantially reducing the volume thereof and precluding objectionable back pressure in the engine. The water flowing through channel 18 will also be heated by the exhaust gases and will assist in cooling and condensing them. The water leaves space 81 at the top thereof, through opening 88a (Figures 7. 9 and 10) in closure plate 84,-and adjacent the bottom thereof, through opening 88 in closure plate 84. The

openings

88, 88a and 882.11 open into the water space 81' of the cover structure 8|.

It will be noted that the opening 88 is at least as large as opening 89 (Figure 9), and opening 88a is substantially smaller than opening 88, providing a restricted outlet. The water entering channel 11 through opening 88 will flow upward through channel 11 under substantial pressure and velocity and will mix, in the top of channel 11, with water discharged thereinto through opening 88a from space 81. The water flowing through channel 11 will also be heated by the exhaust gases and will assist in condensing them. From what has been said, it will be seen that the entering cold water is utilized to best advantage for cooling and condensing the exhaust gases, and is also heated to a derived from such gases is conducive to avoidance of over-cooling of the engine, particularly when it is operating at low speed.

The water discharged under pressure into channel 11, as above, flows through openings 18 into passage 88 (Figure 13) and thence into the cylinder water jacket 13. The water flows downcylinders 48, within th cylinder Jacket 13, and escapes through the restricted openings I21b into the channel I21a, from which it flows into passage I21 and thence, by way of bosses I26 and I38 and mounting plate 26, into tube 23.

Since, as noted, the pump 38 is a constant volume pump and delivers a fixed volume of water per stroke, the amount of water delivered by the pump to the engine cooling system varies directly as the speed of the pump, that is, as the speed of the engine. When the engine is operating at low speed, as when trolling for example, the rate of supply of water to the cylinder water jacket 13 may be insufllcient to maintain it completely filled. In such case the water flows downward about the cylinders and escapes through the restricted openings I21b. But little, if any, water then enters the head space 66 through port 56, and space 66 may then be substantially empty, such water as may enter that space flowing downward therethrough by gravity across the cylinder heads and escaping through port 51. The engine The cold water flowing through will then be adequately cooled while being heated sufliciently to preclude objectionable condensation and assure smooth and efficient operation of the engine. As the speed of the engine increases, the rate of supply of water to the cylinder water jacket 13 increases and water may then flow continuously through port 56 into the head space 66 completely filling it, after which the cooling water flows under pressure in two parallel streams downward through the jacket 13 and the space 66. At high speed operation of the engine, the water flows through jacket 13 and space 65 at increased velocity. Since the amount of heat generated in the engine increases with the speed thereof, the increase in flow of cooling water with increase in engine speed, assures adequate cooling without over-cooling, which assures smooth and eflicient high speed operation of the engine while avoiding objectionable condensation therein of the combustion gases. Likewise, and to the same end, cooling of the engine is adjusted automatically to intermediate speeds thereof.

It will be seen that, by the cooling system of my invention, the extent of cooling of the engine is automatically varied in accordance with engine speed and is such that, at any given engine speed, the engine is adequately cooled, while over-cooling is avoided and smooth and emcient operation without objectionable condensation in the engine of combustion gases is assured. The velocity of flow of cooling water through the channels of wall 15 and through the cover structure at, of the exhaust expansion chamber 14, increases as the engine speed increases. At high speed operation of the engine, there is practically no risk of overcooling, and the problem then becomes one of adequate cooling, which is fully provided for by the cooling system of my invention. At low speed operation of the engine, the water flows through the channels of wall I and through cover structure 8|, of the exhaust expansion chamber 14, at low velocity. The water is then preheated to a greater extent than at high engine speeds, which is desirable. In that connection, at low engine speed the heat generated by the engine is much less than at high engine speed, and the problem then becomes principally one of preventing overcooling of the engine with the attendant objections previously referred to. The increased preheating of the water at low engine speed is desirable as being conducive to avoidance of over-cooling, and the decreased cooling of the exhaust gases is still adequate due to the decreased volume of such gases at low engine speed. The water flowing into mounting plat 26 and thence downward about tube I36 further cools and condenses the exhaust gases while tending to produce a partial vacuum or suction effect in the expansion chamber, which contributes to prevention of objectionable back pressure in the exhaust passages of the engine and to increased efliciency thereof. The exhaust gases discharged into mounting plate 26 mix with the water flowing down the motor support tube 23. The mixture of water and exhaust gases flows from tube 23 into intermediate section 22 of unit 20 and is discharged therefrom under water, through opening d3, as will be clear from what has been said.

The crank case section 41 flares generally away from the cylinder block 46, the transfer passages H4 are straight lengthwise and open into and flare toward crank case section 41, and water passages 80 and I21 are straight lengthwise and flare toward and open through the outer end of cylinder block 46. Likewise, all other passages and recesses in the cylinder block, except the drilled passages or openings, are appropriately formed and disposed to provide draw for die casting, and all seating surfaces on the cylinder block 46 and appurtenant parts are flat and, in general, perpendicular to other seating surfaces, to facilitate machining thereof. The cylinder block and crank case unit of the engine is thus well suited to production by die casting, and such machining of surfaces thereof as may be required can be performed quickly and easily. Likewise, the cylinder head 50 is well suited for die casting, as is the crank case section 92, and the cover plate 85. It will be seen that the engine of my instant invention is so designed and constructed that the stationary parts thereof may readily be produced by die casting, or by stamping, require but little machining, which may be performed with expedition and facility, and may be quickly and easily assembled, rendering it possible to produce an engine of exceptionally high efficiency at comparatively low cost.

It will be understood that changes in detail may be resorted to, without departing from the field and scope of my invention, and I intend to include all such variations, as fall within the scope of the appended claims, in this application in which the preferred form only of my invention is disclosed.

I claim:

1. In an outboard motor unit, an internal combustion engine comprising a substantially horizontal cylinder having a water jacket provided with a water inlet and with a restricted water outlet adjacent its lower side, a head for said cylinder having a cooling water space extending downward across the outer end of said cylinder, said water space opening into the cylinder water jacket adjacent the upper side of the latter and being otherwise substantially closed thereto and having a water outlet adjacent its lower side substantially separate from the cylinder water jacket, the latter with its inlet and outlet providing a first path of flow for cooling water, said head cooling water space providing with its inlet and outlet a second path of flow for cooling water substantially separate from said first path of flow, and means for supplying cooling water to said cylinder water jacket comprising a pump driven at variable speed corresponding to the speed of said engine.

2. In an outboard motor unit, an internal combustion engine comprising a substantially horizontal cylinder having a water jacket provided with a water inlet adjacent its upper side and with a restricted water outlet adjacent its lower side, a head for said cylinder having a cooling water space extending downward across the outer end of said cylinder, said water space having adjacent its upper side a water inlet port opening into the cylinder water jacket and being otherwise substantially closed thereto, said water space being provided adjacent its lower side with a water outlet port substantially separate from the cylinder water jacket and communicating with the water outlet of said cylinder jacket, said cylinder water jacket with its inlet and outlet providing a first path of flow for cooling water and said head water space providing with its inlet and outlet ports a second path of flow for cooling water substantially separate from said first path of flow, and means for supplying cooling water to the water inlet of said cylinder water jacket comprising a water pump driven by said engine.

3. In an engine for an outboard motor unit,

' a horizontal stricted water outlet adjacent its'lower side, and

- a head for said cylinder having'a cooling water space extending downward across the outer end of said cylinder, d water space opening into the cylinder water et adjacent the upper side of the latter and being otherwise substantially closed thereto and having a water outlet adjacent its lower side substantially separate from the cylinder water jacket; the latter with its inlet and outlet providing a first path of flow for cooling water; said head cooling water space providing with its inlet and outlet a second path of flowfor cooling water substantially separate from said first path of flow.

.top of the latter-and being sent its bottom, said cylinder having a water jacket provided with a water inlet and with a re-.

7. In" an outboard motor unit, an internal combustion engine comprising a substantially horizontal water jacketed cylinder having a restricted water outlet adjacent its bottomand a head for said cylinder having a coolingwater space extending downward across'th'e outer end of said cylinder, said space opening adjacent its top into the cylinder-water jacket adjacent the otherwise substantially closed thereto. and having a water outlet adj ajacketed exhaust chamber with the water jacket adjacent the top thereof 4. In an outboard motor unit, an internal combustion engine comprising a substantially horizontal cylinderhaving a water jacket provided water inlet adjacent its upper side ,and

restrictedwater outlet adjacent its lower head for said cylinder having a cool thereof opening into said'cylinder water jacket and being" provided at its under side with. a crank shaft bearing opening surrounded by a cooling water channel opening' into the exhaust chamber water jacket, and

means for supplying cooling water to said channel and thence through the exhaust chamber water jacket to said cylinder water jacket comprising a water pump driven by-said engine.

- 8, In an outboard motor unit, an internal combustion engine comprising a substantially hori zontal water jacketed cylinder having a restricted water outlet adjacent itsbottom and a head for said cylinder ha a cooling water space extending downward across the outer end of said cylinder, said space opening adjacent its top into and said head water space providing with its inlet and outlet ports a second path or flow for cooling water substantially separate from said 5. In an outboard motor unit, an internal combustion engine comprising a water jacketed cylinder disposed with its axis substantially horizontal in the normal use of said engine, the water jacket of said cylinder having a restricted water outlet adjacent its lower side, and a head for said cylinder having a cooling-water space extending downward across the outer end of said cylinder,

said space opening adjacent its upper side intothe cylinder water jacket and being otherwise substantially closed thereto and having a water outlet adjacent its lower side, means for supplying cooling water to said cylinder water jacket comprising a water pump driven by said engine, and means for subjecting the cooling water to heat derived from the hot exhaust gases of said engine in its flow to said cylinder water jacket thereby condensing the exhaust gases and preheating the water prior to its entering said cylinder water jacket.

its lower side, said engine having a water jacketed exhaust chamber with the water jacket thereof opening into said cylinder waterjacket adjacent the upper side thereof, and means for supplying cooling water to the exhaust chamber water jacket and thence to said cylinder water jacket comprising a water pump driven by said engine.

the cylinder-water jacket adjacent the top of the latter; and being otherwise substantially closed thereto and having a water outlet adjacent its bottom, said engine having at one side thereof a water jacketed exhaust chamber with the water jacket thereof opening at its top into said cylinder water jacket and being provided at its under side 7 with a crank shaft bearing opening surrounded 'by a cooling water channel opening into the exhaust chamber water jacket adjacent the bottom thereof, and means for supplying cooling water to said channel and thence through the exhaust chamber water jacket to said cylinder water jacket comprising a water pump driven by said engine.

' 9. In an outboard motor unit, an internal combustion engine comprising a substantially horizontal water jacketed cylinder having a water outletadjacent the bottom of its water jacket,

said engine having an exhaust chamber with a hollow cover structure defining a cooling water space of considerable extent in one plane and of comparatively slight extent perpendicular to said plane, said engine having passages openingfrom the water space of said cover structure into said cylinder water jacket adjacent the top thereof, and means for supplying cooling water to said water space of said cover structure comprising a. water pump driven by said engine.

1 10. In an outboard motor unit, an internal combustion engine comprising a substantially horizontal water jacketed cylinder having a water outlet adjacent the bottom of its water jacket, said engine having at one side thereof a downwardly opening exhaust chamber defined :in part by a wall of channel formation projecting outward from said engine, a hollow cover structure seating on said wall defining a cooling water space of considerable extent in a plane substantially parallel with the cylinder axis and of comparatively slight extent perpendicular to said plane, said wall being separated interiorly into two channels each extending in part across the top of said chamber, one of said channels: opening at its top into said water space and the other of said channels opening at its bottom and at its top into said water space, said engine having engine having a water 1 passages opening from thetop of said other channel into the water jacket of said cylinder adjacent the top thereof, and means for supplying coolin water to said one channel" and thence through said water space and other channel and passages to said cylinder water jacket comprising" a water pump driven by said engine.

. the inner face of said flange defining therewith 11. In an outboard motor unit, an internal combustion engine comprising a substantially horizontal water jacketed cylinder having a water outlet adjacent the bottom of its water jacket, said engine having at one side thereof a: downwardly opening exhaust chamber defined in part by a wall of channel formation projecting outward from said engine, a hollow cover structure seating on said wall defining a cooling water topo! said chamber, one of said channels opening at its top into said water space and the other of said channels opening-:"at'its bottom and at its top into said water space, saidengine having passages opening from the top of said other channel into the water j'acketof said cylinder adjacent the top thereof and being provided at its under side with a crank shaft bearing opening surrounded by a cooling water channel opening into said one channel adjacent the lower end thereof, and means for supplying cooling water to said channel surrounding said bearing opening and thence through said one channel and said space and other channel and passages to said cylinder water jacket comprising a water pump driven by said engine.

12. In an outboard motor unit, an internal combustion enginecomprisinga cylinder block having a crank case at one end and a substantially horizontal cylinder sleeve projecting outward beyond its other end, and a cylinder head secured to said block closing the outer end of said sleeve having an inwardly extending flange seating on the outer end of said block extending about said sleeve in spaced relation thereto defining therewith a waterjacket, said block having a water inlet passage opening through its outer end into said water jacket adjacent the top thereof and a water outlet passage opening through its having two exterior lengthwise ribs disposed at opposite sides of said outlet passage extending radially outward of said sleeve into proximity to restricted water escape openings from said water I jacket to the space between said ribs, said head defining a cooling water space extending across the outer end of said cylinder having a port at its top, opening into said water jacket and a port at its bottom opening into the space between said ribs, said cooling water space being otherwise closed to said cylinder water jacket.

14. The method of cooling an internal combustion engine having a water jacketed cylinder and cylinder head, which comprises supplying water to the cylinder water jacket by a water pump of substantially constant volume per stroke driven by said engine while restrictedly discharging water from the cylinder water jacket independently of discharge of water from the cylinder head water jacket, and supplying to the water jacketof the cylinder head water overflowing thereinto from the cylinder jacket and discharging water from the cylinder head water jacket independently of discharge of water from the cylin-- der water jacket.

15. The method of cooling an internal combustion engine having a substantially horizontal water jacketed cylinder and a cooling water space extending downward across the cylinder head,

bustion engine having a substantially horizontal beyond its other end, and a cylinder head secured to said block closing the outer end of said sleeve having an inwardly extending flange seating on the outer end of said block extending about said sleeve in spaced relation thereto defining therewith a water jacket, said block having a water inlet passage opening through its outer end'into said water jacket adjacent the top thereof and a water outlet passage opening through its outer and adjacent the bottom of said sleeve, the latter REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 743,556 Perkins Nov. 10, 1903 1,375,110 Rowledge Apr. 19, 1921 1,434,348 Bull Oct, 31, 1922 1,457,944 Short June 5, 1923 1,500,668 Church July 8, 1924 1,754,689 MacPherson Apr. 15, 1930 2,063,825 Otwell Dec. 8, 1936 2,227,247 Conover Dec. 31, 1940 GILBERT EQBUSKE.