US2681029A

US2681029A - Propulsion drive unit for boats

Info

Publication number: US2681029A
Application number: US160337A
Authority: US
Inventors: Canazzi Henry Donald
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-05-05
Filing date: 1950-05-05
Publication date: 1954-06-15
Anticipated expiration: 1971-06-15

Description

June 15, 1954 H. D. CANAZZI PROPULSION DRIVE UNIT FOR BOATS 3 Sheets-Sheet 1 Filed May 5 1950 jfepgponaldcazyagji June 15, 1954 H. D. CANAZZI PROPULSION DRIVE UNIT FOR BOATS 3 Sheets-Sheet 2 Filed May 5, 1950 attorney;-

' Zmventor U01) III) June 15, 1954 ANAZZ| 2,681,029

PROPULSION DRIVE UNIT FOR BOATS Filed May 5 1950 3 Sheets-Sheet 5 E 34L 43 y g 2\ 33291575 93 76 76 3 @113 4A l 0 91 71 12: 4. 74/ X C: 2 2/7 1 $3. m: imnn E: 33

I 5 U: 49 J02 4 34 7 J 5106 3 107 10603 r 78 52 101 a 3 g X 55. w l 7'9 Zmvento;

Hang P012414 (211241551,

F g m 5.6mm

(Ittorneg Patented June 15, 1954 ITED STATES PATENT OFFICE Claims.

My invention relates to propulsion drives for boats, and more particularly relates to improvements in boat drives wherein a propulsion unit of the drive is secured to the outboard side of a boat and is operably connected to a motor and to oper-v ating controls within the boat.

Heretoiore, it has been found impractical to provide a small, compact, quiet and efficient stern drive propulsion unit for the reasons that the size of the gears and sundry parts of the drive mechanism and their lubricant reservoir have determined the size of their housing and if small gears and a small reservoir are used to reduce the size of the unit, the heat generated by the small gears at high rotative speeds thins the small volume of lubricant and causes objectionable gear noises. In prior drives no means for maintaining the gear lubricant at a consistency to reduce gear noises at high speeds have been provided so that they have been either large and cumbersome or small and noisy.

in propulsion drives the propulsion unit and the motor have been rigidly secured to the boat so that noises and vibrations generated in operating the drive have been transmitted to and amplified by the boat to an annoying degree.

Furthermore in the installation of prior drives the arrangement of the various services and controls, i. e., the motor cooling and exhaust conduits and the drive unit steering and reversing controls has been such as to require making a separate hole in the boat for each of the service conduits and controls and each hole has required a packing or seal which, only if properly installed and maintained, prevents water from leaking into the boat.

The objects of my invention are to provide a small, compact, quiet and efiicient reversible and steerable propulsion drive unit for boats, to provide an attractive appearing housing which encases a drive mechanism, a cooling system for the drive mechanism and reversing and steering mechanism so that by forming a single large installation hole in a boat the drive unit may be readily installed and operably connected to a motor, to cooling and exhaust conduits of the motor, and to steering and reversing controls in the boat; to provide a resilient support for a drive unit arranged to seal the installation hole against the entrance of water and to cooperate with resilient mountings for the motor in isolating noises and vibrations, generated by operation of the drive mechanism or by movement of the unit through water, thus preventing such noises and vibrations from being transmitted to and ampli- Cir fied by the boat hull; and to provide a stern drive unit with a cooling system operably connected to a motor cooling system and in constant communication with an exhaust conduit in a rotatable steering section of the unit.

In the drawings:

Figure 1 is a side elevational view showing my improved stern drive unit mounted in the stern portion of a boat, shown in section, and operably connected to a motor and controls in the boat.

Figure 2 is a rear elevational view of the drive unit shown in Figure 1.

Figures 3 and 4 are enlarged transverse sectional views taken substantially along the lines 33 and 4-4 of Figure 1.

Figure 5 is an enlarged horizontal sectional view taken along the line 5-5 of Figure 1.

Figures 6 and 7 are enlarged horizontal sectional views taken along lines 66 and l-'i respectively of Figure 1.

Figure 8 is a view similar to Figure 1 but enlarged and having the upper portion of the drive housing broken away to show sundry features of the drive mechanism.

Figures 9 and 10 are enlarged sectional views showing the connections between the shifting mechanism and its flexible control and the connection between the steering mechanism and its flexible control respectively, and;

Figure 11 is a side elevational view of a drive unit similar to Figure 1 but modified to be resiliently connected to the bottom of a boat.

Referring now to the drawings the numeral 28 generally designates a power boat hull having a bottom 2|, spaced side walls 22 and a rear wall or stern 23.

A motor 25 is resiliently mounted in the hull for limited oscillatory movement, as by the resilient mountings indicated at 26 with its drive shaft 21 and its fly-wheel housing 28 directed toward and spaced from the sterm 23. A single large hole 24 isfformed in a wall of the boat, preferably in the center of the stern 23, for the passage therethrough of sundry elements of a propulsion drive unit 30.

In general the drive unit 30 is resiliently secured by a resilient mounting means which isolates noises and vibrations and which preferably seals the installation hole 24 against leakage of water into the boat. The drive unit 3t includes a housing 3| having a rotatable depending propeller carrying steering section 45, and encases a mechanism for rotating the section 45, a reversible propeller drive mechanism 10, a clutch mechanism for controlling the drive mechanism, and a cooling system I for the drive mechanism.

By reason of their encasement by the housing the drive mechanism and the cooling ssytem may be readily extended through the single hole 2t and operably connected to the motor 25 and at the same time the encased reversing and steering mechanisms are also extended through the hole and may be operably connected to suitable controls within the boat.

More specifically stated, and as best seen in Figure 8, the multi-section housing 3! includes an upper section 32, formed with a gear chamber 33 which, being separated from a cooling chamber 36 formed in its lower reduced end portion by a transverse wall 35, is in a heat exchanging relation with the cooling chamber 313. The open top of the chamber 33 is closed by a cap section 36 which is detachably secured to the top of the section 32 by suitable bolts. The section 32 and the cap 36 are each formed with complementary portions which extend horizontally therefrom and, being formed at their outer ends with complementary

external flanges

31 and 38, provide a flanged tubular mounting bracket section 39. The tubular section is secured by bolts 5i to a resilient element 22 of the mounting means M] which in turn is secured to the stern 23 so that the section 32 is spaced from the hole 23 and the outer side of the stern 23. By reason of this manner of resiliently securing the drive unit 39 in spaced relation to the stern 23 and the hole 2 2 noises and vibrations generated by operation of its drive mechanism or by movement of the steering section 45 through water are isolated by the resilient element and are not transmitted to and amplified by the boat.

Since it is preferred to also utilize the mounting means 29 as a seal for the hole 24, the resilient element 32 is formed of a sheet of strong and tough rubber-like material which is extended to overlie the hole 25 and is secured thereabout by a ring 53 and screws 44 thus providing a simple and effective combined resilient mounting and seal for the drive unit.

The steering section 45 of the casing 3| preferably includes an upper section 46 and a lower section 5! operably connected together by a pivot pin and a shear pin (see Figures 5 and 8) for rotating movement about a common vertical axis and for upward swinging movement of the lower section independently of the upper section and about the horizontal axis of the pivot pin when the lower section encounters an obstacle with sufficient force to break the shear pin. To prevent water from entering the steering section at the juncture of the sections 45 and 5! their abutting surfaces are formed to normally interfit as indicatedin Figure'8.

The upper steering section 43 includes an annular body which is formed with a reduced bearing surface 51 concentric with the body and a fur ther reduced tubular bearing boss 48 also concentric with the body and connected thereto by integral radial arms, thus providing through passages between the body and the boss .8 for a purpose to be described later.

The bearing surface 41 is journalled in a flanged bearing 49 secured in the lower end of the reduced portion of the section 32, and the boss 48, being extended above the annular body so that it projects through the cooling chamber 34, the wall and into the gear chamber 33, is journalled in the center of the wall 35 by a radial thrust ball-bearing 49'. A suitable seal is mounted in the wall 35 below the bearing so as to allow the boss 48 to rotate and to seal off communication between the gear chamber 33 and the cooling chamber 34.

The lower section 5| of the steering section includes a tubular body portion 52 which between its bell-shaped upper end 53 and a stream-line hollow enlargement 54 at its lower end is of a flattened substantially elliptical cross sectional shape, and is formed with a rearwardly extending conduit portion 55 below which a horizontally disposed cavitation plate 55 is integrally formed.

A plate El, formed integral with and extended below the enlargement 54 in a plane coincident with the plane of the long axis of the section 5!, cooperates with the body 32 in serving as a rudder for steering the boat when the steering section 4-5 is rotated. A propeller 53 is operably mounted at the rear end of the enlargement 53 with its axis of rotation in co-planar relation with the body 51 and the plate 51, so that when the propeller is rotated its thrust is parallel to the rudder. The thrust of the propeller is thus advantageously used to supplement the steering effect of the rudder in steering the boat. In other words power steering is provided.

To prevent axial movement of the upper section 3-6 in its bearings 39 and a9 and to provide means for rotating the steering section a worm wheel SI of the steering mechanism 3:] is detachably secured to the inner end of the boss 48, and is retained against the inner face of the hearing by a suitable retainer ring. A driving connection, preferably a key (not shown) is provided between the worm wheel and the boss to insure rotation of the section 15 when the steering mechanism is operated.

In the mechanism 50 for rotating the steering section 45 (Figure 7) a shaft 82 is horizontally disposed and at opposite ends of a worm E3, is journalled in bearing bushings secured in bearing bosses 6d and 65 formed on a Wall 33 of the gear chamber 33 so that the worm is in constant mesh with the worm wheel. The shaft 32 is horizontally extended through the wall the tubular bracket section 39, the mounting means 33 and the hole 24, and its enlarged end (see Figure 10) is formed with a squared central bore 33 in which the squared outer end of a flexible drive element til of a flexible drive cable 68 is inserted and secured by a set screw 69.

The flexible cable 38 is extended to some con venient location the boat at which point the flexible element 6? is operably connected to any suitable means for rotating it (e. g. a steering wheel, not shown) so that by rotating the remote end of the element Bl more or less, the shaft 62, the worm 63, the worm wheel 6! and the steering section 45 are likewise rotated more or less, in steering the boat. The construction of flexible drive cables and their mountings are so well known that they need not be further described.

Referring now to the reve sible propeller drive mechanism 78 (see Figure 8) a horizontally disposed shaft TI is journalled in bearings 12 and '13 mounted in the walls of the gear chamber 33 and the cap 36 and is extended through a seal adjacent the bearing 12, the tubular bracket 39 and the mounting means it). The inner end of the shaft "H is operably connected to and driven by the drive shaft 27 by any suitable means which allows a slight gyrating or universal movement between the shafts due to slight misalinement of the shafts or slight movement of the resiliently mounted drive unit 30. A suitable spline connection between the drive shaft 21 and the shaft H is indicated at M.

A pair of bevel gears 15 and 76 are freely rotatable in spaced relation on the shaft ll within the gear chamber 33 and either of the gears may be caused to rotate with the shaft by shifting a clutch body, slidably secured to the shaft, toward the gear to be rotated. The clutch may be of any suitable type, however, for the sake of compactness, capacity and smoothness of operation it is preferred to use a multiple disc type of clutch, wherein a series of clutch discs are slidably secured to opposite ends of the clutch body and are internested in alternate relation with a series of clutch discs slidably secured in tubular concentric extensions of the gears 1'5 and 76.

The internested series of clutch discs, as indicated by dotted lines at 15' and 16 in Figure 8, normally have no driving effect when the clutch body is in its neutral position midway between the gears, but when the clutch body is shifted toward the gear '15 the associated series of clutch discs 55' are engaged and the gear 15 is driven, and when the clutch body is shifted toward the gear E6 the associated series of clutch discs 16' are engaged and the gear 16 is driven.

The bevel gear 15 and T6 are in constant mesh with diametrically opposite sides of a bevel gear ll secured to the upper end of a vertically disposed shaft 18 which is extended through the bore of the boss 48 and is journalled in suitable bearings secured in counterbores in its upper and lower ends so that upon shifting the clutch in the above described manner, the gear l! may be rotated in opposite directions. The bevel gears 15, 16, ll, the worm wheel SI and the worm 63 are lubricated by operating in a suitable oil in the gear chamber 33 and since the chamber 33 is in heat exchange relation with the cooling chamber 3d of the cooling system Hill the oil is cooled and the gears operate quietly. Leakage of oil from the chamber 33 into the cooling chamber 3 is prevented by an oil seal secured in a counterbore in the boss at below the upper bearing and by a seal below the bearing 49 in the wall 35.

At the juncture of the sections 46 and 5! companion jaw clutch elements 8| and 82 are secured respectively to the adjacent ends of the shaft 18 and a shaft 19 journalled in the center of the section 5| in coaxial alinement with the shaft it. The clutch elements 3! and 82 are normally engaged for the transmission of power between the shafts and when the shear pin is broken and the section Si is swung about the axis of the pivot pin, as described above, the clutch elements are separated and transmission of power between the shafts is cut off.

The shaft I9, being thus normally connected to the shaft "58 by the clutch elements 81 and 32, has its upper end journalled in a bearing secured in a boss 83 formed in the center of the bell shaped portion 52 and inwardly spaced therefrom by integral radially disposed legs 84, thus providing passages therebetween for a purpose to be presently described, and has its lower end journalled in a bearing 85 secured in the section 54 at its juncture with the enlargement 5d. A bevel gear 85 is secured to the lower end of the shaft 79 and meshes with a bevel gear *8! secured to a shaft 88 which drives the propeller 58. The shaft 88 is horizontally disposed and journalled in the center of the enlargement 54 by spaced bearings 89 secured in the enlargement, and be ing projected rearwardly beyond the enlarge- 6 ment is secured in the hub of the propeller by any suitable means.

In the mechanism for controlling the drive mechanism it (see Figure 6) and thus reversing the rotation of the propeller 58, a shaft 9| is arranged in spaced parallel relation to the shaft H and is slidably mounted in a bushing secured in a boss 92 formed on the wall 33. A fork 93 being secured to the end of the shaft 9| located within the chamber 33 is formed to engage in a circumferential groove formed medially of the clutch body so that by shifting the shaft 9| the clutch may be shifted between a non-operative (neutral) position and either of its operative positions described above. The shaft 9|, being extended beyond the boss 92 and through the tubular bracket 39, the mounting means 40 and the hole 2t, has its opposite end formed with a central bore 96 in which one end of a flexible pushpull wire 98 of a flexible cable $5 is secured by a set screw 9? (see Figure 9).

The cable 35 is extended into the boat and, near the point previously selected for the location of a steering wheel, the other end of the wire 95 is operably connected to a suitable hand lever (not shown).

Since the shaft H, as viewed from its splined end, rotates in a clockwise direction it will be seen that the arrangement of the drive gears and the blades of the propeller 58 ar such that when the wire is pulled to clutch the gear 15 to it, the boat will be driven forwardly, and when the wire 86 is pushed to clutch the gear 15 to the shaft H the boat will be driven rearwardly. By combining the reversible propeller drive mechanism with the power steering rudder, in the above described manner, steering and control of the boat is improved considerably.

Referring now to Figure 1 the motor 25 drives a water pump P which is supplied with water by an intake conduit I and which, by suitable connections, pumps water through the motor block, through a conventional gas and water exhaust manifold M and into a combined exhaust gas and water conduit E.

The cooling system :08 for the driv mechanism includes a water intake conduit lill which, being extended from a point below the bottom of the boat passes through the mounting bracket 39 and has its inner end operably connected to the intake conduit I by a conduit I02, thus supplying cooling water to the pump P. After leaving the exhaust manifold M the exhaust gases and water are mixed in the exhaust conduit E and, by means of a conduit 33 operably connected to the conduit E and to a conduit extension 3d of the cooling chamber 34, are directed into the cooling chamber 34.

As best seen in Figure '7, the conduit 34 is formed in the bracket section 39 to one side of the fore and aft center of the cooling chamber whereby the exhaust water and gases are caused to swirl in passing therethrough, thus increasing their cooling effect on the plate, the oil and the mechanism in the chamber 33. If desired, a further cooling effect may be obtained by providing the xternal wall surfaces of the chamber 33 and the cap 35 with suitable cooling fins in the manner shown in the drawings.

Referring again to Figure 8 it will be seen that, regardless of the position to which the rudder section 55 may be rotated in steering the boat, the passages formed in the sections 46 and 5| and the conduit 55, are in constant communication with the cooling chamber 34 and provide for the continuous passage of the exhaust gases and water therefrom. Since the exhaust gases and water leave the steering section 45 at the rear end of the conduit 55 which is normally sub merged, exhaust noises are mufrled by the water and by reason of the. conduit 55 being arranged in coplanar relation with the steering section any propulsion effect exerted by the exhaust on the water is utilized in steering and propelling the boat.

It will be obvious that a drive unit so constructed and resiliently secured to a boat and operably connected to the drive shaft and the cooling system of the motor 25 and to controls within the boat, in the above described manner, will satisfactorily perform its intended functions. However, it is preferred to rigidly connect the resiliently mounted motor 25 to the resiliently mounted drive unit 36 by a ri id tubular connecting section H35 to provide a complete resiliently mounted propulsion drive unit for boats.

Accordingly, the section N is formed with a tubular body Hi6 having a bell-like enlargement I07 at one end and an external flange I98 at its opposite end. The enlargement It? complements the fly-wheel housing 28 and is rigidly secured thereto by suitable bolts and the flange H38, being formed to complement the flange 37-38 is secured thereto by the bolts M with the resilient element 42 interposed and clamped tight 1y therebetween. The section 105 (see Figures 6, 7 and 8) serves to encase and maintain the shaft ii in operable alined engagement with the drive shaft 21, and since, end portions of the

control cables

68 and 95 and portions of the conduits H32 and I 03 pass through holes into the body 2% and are secured therein in alinement with the shafts 62 and 9! and conduits I8! and 35 respectively the section I05 also serves to encase the cables, shafts and conduits and to maintain them in operable alinement.

The enclosed ends of the

cables

68 and 95 are secured in the section I65 in alinement with the shafts B2 and 9! by any suitable mounting means (not shown). It is presently preferred that the enclosed ends of the conduits I02 and H33 respectively be secured in spaced holes formed in a coplanar inward extension Hi of the flange 08 as by swaging their ends (see Figures 3, 7 and 8) The ends of the conduits 02 and I03 being anchored in this manner are alined with the conduits HM 3i and to prevent leakage at their junctures a suitably formed gasket 42 which may be formed as an inward extension of the resilient element 42 is tightly clamped between the adjacent faces of the extension I H and a similar coplanar extension 31 of the flange 37 when the flanges are bolted together.

A hand hole H2, being formed in the top of the bod m5, provides access to the section I95 and facilitates operably connecting the driven shaft H to the drive shaft 21, the steering mechanism shaft 62 to its control cable 68, and the reversing mechanism shaft 9| to its control cable 95, in the above described manner. The hand hole H2 is normally closed by a cover plate H3 detachably secured thereto as by suitable screws.

In the modified form of the complete unitary propulsion drive, shown in Figure 11, parts which are identical with above described parts are given the same reference numerals and parts which are modified, but which otherwise correspond to previously described parts, are designated by the same numeral with a small figure 2 as an exponent.

Accordingly the upper section 32 of the unit 38 is extended below the motor and projects through a hole 24 formed in the center of the bottom 2! near the stern 23. And, the bearing 49 located between the section 32 and the steering section 45, is formed with a wide flange disposed eccentrically with respect to the section 3i! so as to extend laterally beyond it and the intake conduit 201 The flange is spaced from the hole 24 and serves as a mounting bracket for the unit and as to its size and the location of its bolt holes, is preferably a duplicate of the flange 31-3il so that the resilient element 42 of the mounting means 56 may be secured to it and to the bottom of the boat substantially in the manner described above in connection with the mounting of the bracket 39 to the stern 23, thus providing a combined resilient mounting for the unit 32 and a seal for the hole 2 5 in the bottom of the boat.

The intake conduit It}! terminates above the steering section so that the latter may be rotated through a full circle (360) by operating the control cable 58 and for this reason the reversing gear 15 and its clutch. it used in the drive unit 3 3 not be used in the drive unit 30 Except as noted the construction and operation of the modified form of propulsion drive is the same as the first form described above.

It should be understood that the forms of propulsion drives shown and described are intended to exemplify the principles of my invention and that various rearrangements and modifications may be made within the scope of the appended claims.

I claim:

1 In a propulsion drive unit for boats; a housing; a propeller carrying rudder section rotatably secured to the housing; a propeller drive mechani m operably mounted in the housing and in the rudder section; a cooling system for the drive mechanism comprising a water intake conduit in the housing, a combined exhaust water and gas conduit in the housing in heat exchange relation with the drive mechanism and in constant communication. with a combined exhaust water and gas conduit in the rotatable rudder section; a mechanism for controlling the drive mechanism; and a mechanism for rotating the rudder section; said. mechanisms and said cooling system conduits being encased by and extended beyond said housing for extension through a single hole in an exterior wall of a boat and being operably connectible respectively to a drive shaft and to a cooling system of an internal combustion motor and to control means mounted within the boat; and means for resiliently supporting said housing in spaced relation to the walls of the hole and the boat; whereby noises and vibrations generated in operating the drive unit and by movement of the rudder section through water are isolated by the resilient supporting means.

2. The combination set forth in claim 1 wherein the resiliently supported housing is extended through the single hole and its inner end is rigidly securable to a motor resiliently mounted in the boat and the resilient supports for the housing and motor cooperate in isolating noises and vibrations.

3. The combination set forth in claim 1 wherein the resilient supporting means for the drive unit is sealingly secured to said housing and to said Wall beyond said hole, whereby said support also serves as a seal for preventing water from entering the boat and the drive unit housing.

4. The combination set forth in claim 1 wherein the resilient means is formed as a resilient gasket having its inner margin sealingly secured to the housing and its outer margin extended beyond the hole and sealingly secured to the Wall to close and seal the space between the housing and the wall against leakage of water therethrough and said gasket is extended inwardly from its inner margin and clamped between the adjacent ends of the intake and exhaust concluits to prevent intake water and the combined exhaust water and gases from leaking into the housing,

5. The combination set forth in claim 1 wherein the propeller drive mechanism includes mechanism for reversing the direction of rotation of the propeller, and wherein the outlet of the combined exhaust water and gas conduit being normally submerged in water is arranged with its axis in coplanar relation with the steering section to utilize any propulsion effect of the combined exhaust on the water in steering and propelling the boat.

6. The combination set forth in claim 1 wherein the combined exhaust Water and gas conduit of the cooling system is operably connectable to the combined exhaust water and gas conduit of an internal combustion engine and enters one side of a cooling chamber in the housing in heat exchange relation with a gear chamber of the drive mechanism, thereby causing the exhaust gases and water entering the cooling chamber to swirl in the chamber for more effective cooling of the gear chamber before passing into and through the exhaust conduit in the rotatable rudder section.

7. A propulsion drive unit for boats comprising an internal combustion motor resiliently mounted in the boat; a housing; a propeller carrying rudder section rotatably secured to the housing; a propeller drive mechanism operably mounted in the housing and in the rudder section; a cooling system for the drive mechanism comprising a water intake conduit in the housing, a combined exhaust water and gas conduit in heat exchange relation with the drive mechanism and in constant communication with a combined exhaust water and gas conduit in the rotatable rudder section; a mechanism for controlling the drive mechanism; a mechanism for rotating the rudder section; said drive mechanism, said cooling system and said controlling and said rotating mechanisms being encased by and extended through said housing and being operably connected respectively to the motor drive shaft, to the motor cooling system and to control means within the boat, said housing being rigidly connected tosaid motor and freely extended through a single hole in a wall of the boat for submersion of its rotatable rudder section in water; and a resilient support means for the housing cooperating with the resilient mountings of the motor in isolating noises and vibrations generated in operating the drive unit and by movement of the rudder section through water.

8. The combination set forth in claim 7 wherein the housing is formed of inner and outer sections and the resilient supporting means is formed as a resilient gasket having its inner margin interposed and tightly clamped between inner and outer sections of the housing and between the alined opposite end walls of the intake and exhaust conduits to prevent transmission of noises and vibrations and leakage of water therebetween, and to prevent leakage of intake water and the combined exhaust water and gases from said conduits and into the housing, and having its outer margin extended beyond the sections and the hole and sealingly secured to the wall, thereby preventing water from leaking into the boat.

9. The combination set forth in claim 7 wherein the combined exhaust water and gas conduit of the cooling system enters one side of a cooling chamber in heat exchange relation with a gear chamber in the housing, thereby causing the exhaust gases and water to swirl in the cooling chamber for more effective cooling of the gear chamber before passing into and through the exhaust water and gas conduit in the rotatable rudder section.

10'. In a propulsion drive unit for boats; a housing; a propeller carrying rudder section rotatably secured to the housing; a propeller drive mechanism operably mounted in the housing and in the rudder section; a cooling system for the drive mechanism comprising a water intake conduit in the housing, and a combined exhaust water and gas conduit in the housing in heat exchange relation with the drive mechanism and in constant communication with a combined exhaust water and gas conduit in the rotatable rudder section; a mechanism for controlling the drive mechanism and a mechanism for rotating the rudder section; said mechanisms and said cooling system conduits being encased by and extended beyond said housing for extension through a hole in an exterior wall of a boat and being operably connectible respectively to a drive shaft and to a cooling system of an internal combustion motor and to control means mounted within the boat; and means for operably supporting said housing on said external wall of the boat.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,000,494 Clement Aug. 15, 1911 1,564,742 Acker Dec. 8, 1925 1,798,596 Fahrney Mar. 31, 1931 1,943,288 Chandler Jan. 16, 1934 2,103,087 Morris Dec. 21, 1937 2,209,301 Johnson July 23, 1940 FOREIGN PATENTS Number Country Date 516,974 Great Britain Aug. 14, 1939 890,890 France Nov. 19, 1943