US2528480A

US2528480A - Outboard motor

Info

Publication number: US2528480A
Application number: US675920A
Authority: US
Inventors: Eldon M Wilson; Pollock Latham
Original assignee: SOUTHERN ENGINEERING Co I
Current assignee: SOUTHERN ENGINEERING Co I; SOUTHERN ENGINEERING COMPANY Inc
Priority date: 1946-06-11
Filing date: 1946-06-11
Publication date: 1950-10-31
Anticipated expiration: 1967-10-31

Description

Oct. 31, 1950 E. M. WILSON ETAL OUTBOARD MOTOR Filed June 11, 1946 Sheets-Sheet 1 [200m /l /Z l V/z so/v, 91 1471 44/14 A 044 oc/r,

" INVENTORS ATTORNEY Oc 1950 E. M. WILSON ET AL 2,528,480

OUTBOARD MOTOR 4471/4; p 06 INVENTORS Oct. 31, 1950 E. M. WILSON ET AL 2,528,480

OUTBOARD MOTOR Filed June 11, 1946 Y 5 Sheets-Sheet 5 4200/v/W. /////A 50% 442 /4/14 9041. our,

INVENTORS ATTORNEY.

1950 E. M. WILSON ET AL 2,523,480

OUTBOARD MOTOR Filed June 11, 1946 5 Sheets-Sheet 4 1 -8- fZDO/VM W/LSO/V,

ZATHAM Q04; oc/r,

' INVENTORS OUTBOARD MOTOR 5 Sheets-Sheet 5 Filed June 11, 1946 w m w 1 a I v. m w m 7. w w 3 w 4 p n.

e W w I r .1 1M X a 3 m M TE 5 w,

INVENTORS firroewzx Patented Oct. 31, 1950 OUTBOARD MOTOR Eldon M. Wilson, La Canada, and Latham Pollock,

Los Angeles, Calif, assignors to Southern En- Incorporated, Burbank, Calif, a corporation of California Application June 11, 1946, Serial No. 675,920

.gineering Company,

7 Claims. 1

The present invention relates to outboard motors, and is directed to the provision of a new and improved outboard motor embodying many advantageous features not found on any prior machine to our knowledge.

One of the principal shortcomings of outboard motors heretofore known has been the lack of a manually controllable clutch in the propeller transmission mechanism which could be disengaged at will to permit the propeller to stop while the engine idles. Thus, when it has been desired in the past to bring the boat to 'a standstill, the only course open has been to kill the engine and then to restart it when ready to move on. Twocycle engines, which power the great majority of all outboard motors, are sometimes dificult to start even when hot, and frequent restarting necessitated by the absence of a clutch is a serious inconvenience and annoyance.

The-omission of a clutch has not been due solely to lack of foresight on the part of outboard motor designers, nor to a desire to reduce the size, weight, and cost of the unit, but has been dictated primarily by the difiiculties experienced in obtaining adequate cooling of the engine when the clutch is disengaged. This is due to the fact that all outboard motors have heretofore been water-cooled, and the cooling water has been circulated through the cylinder jackets by a pump submerged beneath the water level and driven from the propeller shaft or the vertical drive shaft. Thus, when the drive shaft or propeller shaft were stopped by disengaging the clutch, the pump stopped also and the circulation of cooling water ceased, with resultant heating of the engine. Attempts to overcome this difficulty by driving the pump directly from the engine crankshaft resulted in other complications and were generally unsatisfactory.

The present invention, however, eliminates the quirements of such a unit when operating with the clutch disengaged.

Another object of the invention is to provide a novel clutch construction combining simplicity,

compactness, light weight, absolute reliability, and low cost of manufacture. In this connection, one of the features of our novel clutch construction resides in the shape and arrangement of the driver and driven member whereby any oil seeping down into the clutch compartment from the engine crankcase is thrown outward by centrifugal force from the driver and is prevented from coming in contact with the clutch facings.

A further object of our invention is the provision of a novel shell or outside casing for the engine which constitutes a volute housing for the blower fan, In this way, the outside casing of the engine serves the several functions of providing an ornamental and protective covering for theentire power unit; providing a volute housing of high efliciency for the centrifugal blower; and providing a shroud for directing the cooling air from the blower down over the cylinders. By thus eliminating a separate blower housing and cylinder shroud in addition to the'usual protective casing the bulk of the outboard motor is reduced to a minimum, resulting in a compact unit of pleasing appearance and light weight.

These and other objects and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiment thereof, reference being had to the appended drawings wherein Figure 1 is a top plan view of an outboard motor embodying the principles of our invention;

Figure 2 is a partially sectioned side-elevational View of the same;

Figure 3 is an enlarged sectional view of the power head and clutch mechanism;

Figure 4 is a still further enlarged fragmentary view of Figure 3, showing the clutch in disengaged condition; s

Figure 5 is a sectional view, taken along the line 55 in Figure 4, showing the preferred arrangement of Y the eccentric wheel, which actuates the clutch;

Figure 6 is a similar view of an alternative arrangement of the eccentric wheel and rollers, which provides positive engagement of the clutch and eliminates the need for a clutch spring;

Figure '7 is a partially sectioned side elevational view of the construction shown in Figure 6;

Figure 8 is a sectional view, drawn to enlarged. scale and taken along the line 88 in Figure 3,

showing the construction of the cooling-air fan 1 chamber;

Figure 9 is a partially sectioned side elevational ders.

'plane'bya plurality of bolts, not shown. blower is of the centrifugal type and comrim and said flange.

view of the outboard motor turned 180 around to drive the boat in reverse, illustrating the maner in which the anti-tilt lock plunger is cammed down behind a pin bolt on the transom bracket to prevent the motor from being tilted; and

Figure is a vertical section taken through an alternative embodiment of the clutch mechanism.

Reference is had now to the drawings, wherein the reference numeral It designates the power head of the outboard motor in its entirety, said power head including the motor H with its related accessories such as the carburetor, magneto, fuel tanks, and starter. The lower unit is indicated at E3, and comprises a shaft housing i l enclosing the drive shaft l5, clutch l6, gears ll, and propeller IS. The outboard motor is adapted' to be mounted on the transom of a boat by means of a transom bracket 22, and is steered by a tiller bar 24 which is fixed to the top end of the shaft housing l4 and extends forwardly therefrom.

In the preferred embodiment of our invention, the motor ll takes the form of a two-cylinder, two-cycle, air-cooled engine, having a crankshaft 26 disposed vertically and the cylinders Z'i arranged in line, to the rear of the crankshaft. The two cylinders and the top half 28 of the crank case- (or rear half as it appears in the drawings) are preferably cast en bloc, and a separate pan or bottom crankcase portion 29 is bolted to the top half 28. A' carburetor 38 is mounted on the front end of the bottom crankcase'portion 29 as shown, and the fuel-air mixture from the carburetor is drawn into a manifold. chamber 3% and thence through reed valves 32 into separate crankcase compartments 33 and 34 by the pumping action of the pistons, as is well understood in the art. The crankshaft is journaled in top, center, and bottom bearings 35, 35' and 31, respectively, said center bearing being supported in a solid partition as which divides the crankcase into the tWo'pressure-tight compartments 33, 35.

The top end of the crankshaft 26 projects above the end of the crankcase and has a magneto rotor ll mounted thereon in the usual man ner. Thestator 3'2 of the magneto is mounted on the top end of the crankcase in any suitable fashion, and has an operating lever i3 extending forwardly from the bottom side thereof, said lever preferably being also connected to the carburetor throttle valve by suitable linkage (not shown) so that the throttle is closed simultaneously with retarding of the spark.

The power head H3 is enclosed by a streamlined cast metal shell 56 which has the dual function of protecting the operator from contact with the hot engine, while at thesame time providing a housing for the cooling air blower 5i and a shroud for directing the air down over the cylin- The shell is preferably made in two halves to facilitate coring the casting, said halves being joined together in longitudinal vertical The prises an annular rim '52 having a radial flange 53 extending outwardly from the bottom edge thereof, with a plurality of angularly spaced, radially extending blades 5% fixed to both said The blades 54. are preferably curved, as shown in Figure 8, which has the effect of improving the efficiency of the blower. An overhanging portion 55 of each blade projects radially inward over the top of the rim 52, and the rim 52 is pressed over the outer shell of the magneto rotor at to bring the bottom edge of said overhanging blade portions into contact with the top of the rotor shell.

The housing for the blower 5! is in the form of a volute, and is defined in part by the shell 56 and inv part by a horizontal partition 55 cast integrally with the two halves of the shell and disposed in closely spaced relation beneath the flange 53. The partition 56 is formed with a circular opening 5? concentric with the crankshaft 2'5, through which the latter projects. Also cast integrally with the left hand half of the shell 5% (the top half, as seen in Figure 8) is a vertical partition 58 which is joined with the side and top of the shell and projects laterally inward to the inner edge of the horizontal partition 55. The left hand portion of the horizontal partition 55 terminates in an edge 59 which extends rearwardly from the opening 51 to the back end of the shell 5%, parallel to the axis of the cylinder N and offset slightly to one side thereof, as shown in Figure 8. The edge 59 of the partition 55 serves to confine the cooling air to the finned cylinders 2'1, closing off the open spaces alongside the cylinders through which the air would otherwise be wasted. A circular opening 258 in the partition 56 directs a portion of the air down .over the finned exhaust pipe 25i to cool the latter. The right hand half of the partition 55 terminates rearwardly in a shelf 252, the edge of which extends rearwardly from the opening 51 parallel to the opposite edge 59' to a point approximately even with the head end of the cylinders, where it is cut off to provide an enlarged opening through which a substantial portion of the air is directed down over the finned cylinder heads.

Cooperating with the shell 50- and partition 56 is a curved vertical wall it which may be made of sheet metal and which is attached by screws at one end 61 to the inner edge of the partition 58 and'at the other end 62 to the shell 59. The wall Bil extends from the horizontal partition 56 up to the bottom surface of the top wall of the shell 5t, and is shaped to conform closely to the curvature of the shell. The end 6! of the wall 68 lies closely adjacent to the outer periphery of the blower 5|, while the opposite end 62 of the wall, diametrically across the blower, is tangent to the shell 50. The chamber thus formed between the blower wheel and the wall is substantially a volute, increasing uniformly in cross sectional area from end 6! to end 62.

Air is drawn into the blower housing through a circular intake opening 55' in the top of the shell 59 concentric with the axis ofthe blower, and through a plurality of radially extending slots 57 arranged in a circle around'the opening 65, as shown in Figure 1. These slots 6'! provide the requisite cross sectional area for the intake opening, and at the same time afford a protective grill for preventing entrance of any foreign object into the blower which might damage the same or obstruct the free passage 0f air. The opening 65 is further protected by a rope-starter wheel 16 which is bolted at 69 to the top of the magneto rotor housing ll and which is disposed slightl above the opening, said wheel having a somewhat larger outside diameter than the intake opening so that the latter is completely sheltered under the starting wheel. Air from the blower 5| is discharged through the opening 66 defined by the vertical edge BI and the opposite wall of the shell 50, and is directed down over the finned cylinders and confined thereto by the downwardly curved rear end portion of the shell 50, being discharged to the atmosphere through an opening II in the bottom of the shell.

The blower housing construction described in the paragraphs above, utilizing the outer shell 50 of the power head for the greater part of its wall area, provides a unit of the very minimum bulk, which is an important consideration in outboard motors. Such motors are usually transported in automobile trunks and, at best, are unwieldy to handle. Furthermore, since they are usually attached to relatively small boats, a motor of excessive size presents an incongruous appearance.

In addition to the consideration of size, the volute chamber construction, with its uniformly increasing cross-sectional area between points 6| and 62 contributes appreciably to the overall efiiciency of the centrifugal blower, reducing the power required for cooling the engine.

The lower unit I3, as brought out previously, comprises a shaft housing I4 which encloses the drive shaft I5 and, at its upper end, contains a clutch I6. The shaft housing I4 is preferably die cast in four

longitudinal sections

75, 16, TI and 18, which are joined together as shown in Figure 2.

The top section 15 of the housing is cylindrical in shape and is provided at its upper end witha cup-shaped portion 90 of enlarged diameter which receives an annular mounting flange portion 8| projecting axially downward from the bottom end of the crankcase. The power head I is secured to the top section I of the lower unit I3 by means of two bolts I9 on opposite sides of the motor which extend through aligned bolt holes in the cup-shaped portion 80 and in the crankcase. The hollow interior of the housing section I5 is divided by a partition 62 to form an upper compartment 83 which is separate from the balance of the interior of the shaft housing. In the bottom portion of the partition 82 is a sleeve bearing 84 within which the drive shaft I5 is journaled. The shaft I5 is also journaled adjacent its bottom end in a second sleeve bearing 85 (see Figure *2) which is supported by a horizontal partition 86. The gears I! are contained within a compartment 90 formed by companionate cavities in sections TI and I8, and comprise a beveled pinion 9| fixed to the bottom end of shaft I5 which meshes with a beveled gear 92 mounted on and pinned to the horizontally disposed propeller shaft 93. The shaft 93 is journaled in bearings 94 and 95 and projects rearwardly from its housing, the propeller I8 being mounted thereon in the usual manner.

The shaft housing I4 also serves as an exhaust pipe through which the exhaust gases from the engine are carried for under-water discharge, and to this end, the top section is provided on its back side with a port 98 which communicates with the open interior of the housing. The exhaust pipe I of the engine is bolted to said port, andthe exhaust gases are carried down through the hollow shaft housing and discharged beneath the water through a flattened tail pipe I00 projecting rearwardly from the housing below the anti-cavitation plate IOI and in closely spaced relation thereto.

The drive shaft I 5 is arranged coaxial with the crankshaft 26 of the engine and is adapted to be connected thereto by the clutch mechanism I6 which will now be described.

In its preferred form, illustrated in Figures 3 and 4, the clutch I6 comprises a driver I05 and driven member I06, the driver I05 being in the form of an inverted cup having a sunken center, and the driven member I06 being disposed beneath the driver and within the confines of the outer wall thereof. The driver 05 is bolted to the bottom side of a coupling member II9 having an upwardly extending fiat tongue I I I which is slidably and non-rotatably disposed within a correspondingly shaped hole I01 in the end of the crankshaft. This construction provides a driving connection between the crankshaft andfclutch driver which prevents the transmission of end thrust forces from either member to the other, and also provides a quickly separable coupling permitting the power head I0 to be lifted off of the lower unit when the two mounting bolts 19 are removed. The hub of the clutch driver I05 has a central bore I I2 into which the outer race II3 of a ball bearing H4 is pressed. The top edge of the outer race II 3 abuts against the bottom surface of member I I, while the bottom edge of the race is engaged by an inwardly turned flange II5 on the driver hub. The inner race, designated at H6, is pressed onto a stub portion E20 Of reduced diameter at the end of the shaft I5, the bottom endof said race abutting against a shoulder IZI on the shaft, while the top end is engaged by a retainer ring.

The downwardly turned outer flange I22 of the driver 505 is conical in shape and is engaged on its inner face by a clutch facing I23 of corresponding conical shape which is secured by countersunk screws H9 to the outer periphery of the driven member I655. The driven member I06 is formed with a hub I25 having a square hole I26 broached through the center thereof which receives a portion I of square cross section on the shaft I5. By virtue of this construction, the driven member I06 is slidable axially along the shaft but is held against rotation with respect thereto. The driven member is yieldingly urged into engagement with the driver by means of a spring I 3I which embraces the shaft I5 and bears against the bottom end of the hub I25. The bottom end of the spring i3I bears against a thrust washer I32 which is welded to the shaft I5 just above the bearing 24.

The advantages of the clutch construction described are many. Probably the most important of these advantages is the way in which the clutch facing is protected from oil which unavoidably seeps down through the bottom bearing 31 of the engine from the crankcase. Such oil drops into the cavity I33 in the top of the member H0 and is thrown outwardly by centrifugal force to the inside surface of the mounting flange 8| where it runs down into the compartment 83 and collects in the bottom thereof. The clutch driven member I05, being enclosed on the top and sides by the driver 505, is completely sheltered from any oil and enjoys complete protection therefrom. The oil then seeps through the clearances of the shaft bearing 84 to lubricate the latter and is-expelled through the tailpipe I99 with the exhaust. The partition 82 prevents the entrance of exhaust gas into the compartment 83 where it would foul the clutch facings and escape through the opening MI.

Another advantage of our improved clutch lies in the arrangement of the clutch spring I3I, thrust washer I32, driven member I 536, driver I 05, andball bearing IM, whereby the thrust of the spring is taken in both directions by the drive the driven member.

comes to a stop as soon as the clutch is disenshaft I5. By reason of this construction, the thrust of the spring I3I is isolated from the engine crankshaft, preventing undue wear on the thrust faces of the crankshaft main bearings.

Another advantageous'feature of the clutch described resides in the fact that disengagement of the clutch is accomplished by pulling the driven member E89 down out of contact with the driver, and this is done by a shift lever I49 (to be described in more detail presently) which engages Since the driven member gaged, it will be seen that there is no running friction between the shift lever M9 and the driven member I86 while the clutch is disengaged, which is a distinct advantage inasmuch as it eliminates the need for a special throw-out bearing which is necessary in the more widely used multiple disk clutch,'or in other clutch constructions wherein the shifting lever acts on the constantly rotating driver.

The clutch I6 is disengaged by means of the shift lever M9 which extends through an opening MI in the front wall of the shaft housing top section I5, and is pivotally mounted on a pin M2 for swinging movement in a vertical plane. The inner end of the lever I58 is bifurcated to form a fork I43, the fingers of which are disposed within a groove I44 in the hub I on opposite sides thereof. Pressed into a longitudinally extending hole I45, drilled in the outer end of lever arm I49, is a pin I46 uponwhich is journa-lled eccentric I5Il. The outer rim of the eccentric I59 rides on a pair of laterally spaced rollers 55I and I52 disposed below the eccentric and positioned equidistantly on opposite sides of the axis thereof, said rollers being journalled on pin bolts i53 which are screwed into tapped holes formed in the outer face of a flange I54. The eccentric I58 7 and rollers I5 I, I52 are arranged so that when the low point of the eccentric is bearing on the rollers, as in Figure 5, the clutch driven member I86 is held in full engagement with the driver I35 by the spring I3I. When the high point of the eccentric I59 is resting on the rollers, however, the

outer end of the lever arm I49 is raised, causing the fork 63 to be depressed and the driven member I96 to be pulled down out of engagement with the driver. Two pairs of angularly spaced notches I and I56 (see Figure 5) are formed in the rim of the eccentric I59, on the high and low sides respectively, and these notches are adapted to receive the rollers I55, E52 when the eccentric is in either of its operative positions, providing a detent action which prevents the eccentric from rolling out of either operative position when the controlling means is released.

Operation of the clutch is effected by means of a twist-grip handle I69 having a cylindrical shank I6I which is journaled within a bore I52 in a member I83 pivoted at I94 on the outer end of the tiller bar 24. The purpose of the pivotal connection I84 is to permit the handle let to swing upwardly in the event the motor is tilted, as will be pointed out mor fully hereinafter. The shank wound strands of stainless steel wire and is capa- I5 to permit such steering movement.

ble of transmitting a considerable torque in either direction of rotation. Thus, it is seen. that engagement or disengagement of the clutch I6 can be effected by merely turning'the twist-grip handle I66 through 139, the torque thus applied being transmitted the cable I56 to the eccentric 459 to rotate the latter and thereby swing the operating arm I69 up or down, as the case may be.

Steering of the outboard motor is also accomplished by swinging the tiller bar 24 in the desired direction, the lower unit I3 being pivotally supported on the transom bracket 22 for swinging movement about the axis of the drive shaft To this end, the cylindrical top section I5 of the shaft housing is journalled within a vertical bore H6 in a tubular barrel portion H? which is integral with a bracket member I199. The bracket member I88 extends forwardly from barrel portion II 'I and is pivotally connected by a pin I8I to the vertical flange I82 of a clamp member I83, said clamp member I83 being formed with a downwardly extending backing plate Hit, which bears against the back side of the transom 29. At its front end, the clamp I83 has a downwardly extending arm I85 terminating in a boss I86 having a threaded aperture therein which receives a clamping screw I99. At its rear end, the screw I99 has a bearing plate I9I pivotally connected thereto which is engageable with the .front surface of the transom 29 to -secure the transom bracket thereto, while the frontend of the screw has a handle I92 by which the screw can be turned.

During normal operation'of the outboard motor, when the boat is being driven straight ahead, the thrust of the propeller acting in a forward direction on the bottom of the lower unit produces a counterclockwisemoment on the outboard motor which is resisted by engagement of a notch I94 on the lower front end ofthe barrel portion I'I'I with a transversely extending thrust, pin I95, which extends through alined holes I98 in a pair of laterally spaced flanges I97 extending rearwardly from the backing .plate I84 on opposite sides of the barrel member I'I'I.

In order to accommodate variations in the inclination of the transom 29 encountered in different makes and models of boats, the flanges I9T are provided with a plurality of pairs of holes I96 which are arranged in an are described about the pin IBI as a center. Thus, if a particular transom is inclined upwardly and rearwardly from the bottom of the boatand it is found that the outboard motor is tilted at an undesirable angle, the pin, I95 can be withdrawn and reinserted through any other pair of holes I96 to bring the unit to a vertical position or to any desired degree of angularity.

The notch I94 engages thepin I95 on the back side only thereof to take the thrust of the propeller when the latter is driving the boat forwardly and, being open on the front side, allows the unit to tilt upwardly about the pin I8I if the propeller or skeg strikes an obstruction. Damage to the propeller and other parts of the outboard motor is thus avoided by allowing the unit to yield and ride over the obstruction, the normaldriving position being resumed'as soon as the lower unit has cleared the obstacle. Alimit stop arm I98 projects downwardly and'forwardly from the front end of the bracket member I86, and is engageable with the clamp member I83 to limit the angular movement of the outboard motor and prevent the propeller from'being thrown out of the water if an'obstruction is hit at high speed. The pivotal connection of the twist-grip handle I60 with the tiller bar 24, described earlier, allows the handle to fold upwardly when the unit tilts and thus prevents the handle from being torn out of the operators hand by the sudden violent angular deflection of the handle. This arrangement also affords protection to the operators hand against injury which might otherwise result if rigid tiller bar handle were to strike the bottom of the boat or the transom. The flexible cable I66 merely bends when the tiller bar handle folds up, without disturbing the eccentric I50 or the clutch I6.

One of the features of the present outboard motor is that it can be turned 180 to drive the boat in reverse, and in this condition, with the direction of propeller thrust reversed, the unit must be restrained against tilting, as the propeller would otherwise push the bottom end of the lower unit up out of the water. Accordingly, we have provided an anti-tilt lock device, designated generally by the reference numeral 200, which is operated automatically when the outboard motor is turned more than 90 in either direction from straight ahead, to lock the unit to the transom bracket.

The anti-tilt lock 200 comprises a plunger 20I which is slidably disposed within a vertical bore 202 provided in the body of the bracket member I80 immediately ahead of and parallel to the barrel portion Ill. The plunger 20I is yieldingly urged upwardly by a spring 203 embracing the plunger and bearing against the bottom of a bushing 204 which is pinned or otherwise secured to the plunger. The spring 203 and bushing 204 are contained within a counterbore 205 at the top end of the bore 202, said spring bearing at its bottom end against the shoulder 206 formed by the junction of the counterbore with the bore. The bore 202 opens through the bottom of the bracket member I80, and the bottom end of the plunger MI is normally retracted into the bore so that it clears the thrust pin I95.

The plunger 20I is adapted to be cammed down to a position behind the pin I95, thereby locking the unit against tilting movement, and this is accomplished by an annular cam 2l0 which engages and acts upon the top end of the plunger. The cam 2 I is formed integral with the top section I5 of the shaft housing and comprises a radially outward extending flange, the bottom surface of which bears on the plunger 20!. The rear half 2 of the circular flange is the low side of the cam and lies in a horizontal plane,

while the front half of the flange rises from I each side of the shaft housing in the manner of a spiral ramp to a flat high point 2 I 2 at the front end of the housing. The cam 2I0 is so arranged and proportioned that when the outboard motor is in the straight-ahead position shown in Figure 1, with the top end of the plunger 20I in engagement therewith, the bottom end of the plungor is fully retracted into the bore 202, and the unit is free to tilt. When the outboard motor is turned more than 90, however, the cam 2E0 depresses the plunger 20I down behind the thrust p1n I95, locking the unit to the bracket member I80.

The arrangement illustrated in Figures 6 and 7 shows an alternative construction for the clutch actuating mechanism, featuring positive engagement of the clutch it instead of the spring-loaded engagement of the previously described construction. In this embodiment,the eccentric I is disposed between and turns on two pairs of rollers 220 and ZZI which are located at the top and bottom of the eccentric. The two top rollers 220 are journalled on pin bolts 225 which are screwed into suitable tapped holes provided in the cupshaped element 80, while the two bottom rollers 22! are journalled on pin bolts 226 which are screwed into the flange I54, as in the preceding embodiment. The throw-out mechanism is initially set up so that when the eccentric I50 is turned to bring its high point down to the bottom position, the clutch driven member will be just disengaged from the driver. Engagement of the clutch is then effected by turning the eccentric as far as it will turn in either direction, at which point the driven member will be solidly against the driver and further rotation of the eccentric prevented.

With this arrangement of the eccentric I50 between oppositely disposed pairs of

rollers

220 and 22!, the shift lever M0 is positively swung downwardly to engage the clutch, as well as upwardly to disengage the same, enabling the clutch spring I32 to be dispensed with. The operation of this clutch actuating mechanism is not affected by wear of the clutch facing I23, inasmuch as the eccentric is turned until full engagement is obtained, and a worn clutch merely requires Slightly more of a turn on the eccentric I50 to take up'the extra clearance.

Still another embodiment of our improved clutch is illustrated in Figure 10, wherein the clutch driver i and driven member I06 are substantially the sameas i the preceding constructions, but with an alternative clutch actuating mechanism. In this instance, the hub of the driven member I06 comprises a downwardly extending cylindrical sleeve 250 which slidablyreceives the cylindrical top end of the drive shaft E5. The hub 250 is connected to the shaft I5 to drive the latter by a pin 26I which extends diametrically through the shaft I5, and the ends of said pin being slidably disposed within longitudinally extending slots 252 formed in the inner surface of the hub. The slots 262 thus permit the hub 260 of the driven member to slide up and down on the shaft I5, while the pin 26I transmits the drive from the clutch member I06 to the shaft l5] Screwed onto the bottom end of the hub 250 is a thrust ring 253 having a shoulder 264. which bears against the bottom end of a throw-out member 265 and which is also engaged by the spring I3I. The member 255 has a smooth bore 260 which serves as a journal for the hub 260, and external threads 210 of coarse pitch formed on the outside surface thereof which are engaged in companionate internal threads in a stationary bushing member 2! I. The member 2?! is screwed into a horizontal partition 2'l2 formed integrally with the shaft housing top section I5. The top end of the throw-out member 265 is enlarged in diameter and has a plurality of radially extending tapped holes 2'53 formed therein, and screwed into one of said holes is the clutch lever 215 which extends forwardly through a transversely elongated opening 2?!) in the front wall of the housing element E5 to a point conveniently within reach of the operator.

The clutch is actuated by swinging the lever 2M horizontally from one side to the other, which rotates the throw-out member 265 and causes the latter to move up or down by reason of its threaded engagement with the stationary member 2'. When the throw-out member moves down, the clutch driven member I05 is carried down with it by the ring 255 which is screwed onto the end of the hub 200 and which is engaged by the bot-v am no and not, in any sense restrictive on the same. To

those skilled in the art, there will occur many changes in the shape and arrangement of the several parts going to make up the machine in its entirety, but such changes do not depart from the broad concept of the invention defined in the appended claims.

We claim:

1. In an outboard motor having a crankshaft, and a propeller drive shaft, a clutch serially arranged between said crankshaft and said drive shaft, the combination of a lever arm operatively connected to said clutch and pivotally supported for swinging movement between clutch-engaged position and clutch-disengaged position, an eccentric wheel journalled on said lever arm and e'ngageable with a stationary element whereby rotation of the wheelcau'ses said lever arm to move from one of said positions to the other, and a control handle op'eratively connected to said eccentric wheel to turn the same.

2. In an outboard motor having a crankshaft, a propeller drive shaft, and a clutch serially arranged between said crankshaft and said drive shaft, the combination of a lever arm operatively rolling on a pair of angularly spaced rollers disposed on one side of the center of the eccentric wheel whereby rotation of the wheel causes said lever arm to move from one of said positions to the other, and a control handle operatively connected to said eccentric wheel to turn the same.

3. In an outboard motor having a crankshaft, a propeller drive shaft, and means for securing said outboard motor to a boat and providing for pivotal movement of the outboard motor about a substantially vertical axis, the combination of a clutch serially arranged between said crankshaft and said drive shaft, a tiller bar connected to said outboard motor for turning the same to steer the boat, a lever arm operatively connected to said clutch and pivotally supported for swinging movement between clutch-engaged position and mg movement'between clutch-engaged position and clutch-disengaged position, an eccentric wheel journalled on said lever arm, the peripheral edge of said wheel rolling on a pair of angularly spaced rollers journalled on said outboard motor on one side of the center of the eccentric wheel whereby rotation of the latter causes said arm to move from one of its positions to the other, the periphery of said wheel being notched to receive said rollers when-the wheel is in either of its operative positions to prevent the wheel from turning by itself, a handle journalled on said tiller bar, and a flexibletorque-transmitting cable connecting said handle to said eccentric wheel whereby the latter is turned when the handle" is turned. a

5. In an outboard motor having a crankshaft, a propeller drive shaft, and means for securing said outboard motor to a boat' and providing for pivotal movement of the outboard motor about a substantially vertical axis, the combination of a clutchserially arranged between said crankshaft and said drive shaft, a tiller bar connected tosaid outboard motor for turning the same to steer the boat, a lever armoperatively connected to said clutch and pivotally supported for swinging movement between clutch-engaged position and clutch-disengaged position, an eccentric wheel journalled on said lever arm, two pairs of angularly spaced rollers journalled on said outboard motor on opposite sides of the axis of said eccentric wheel, the periphery of said wheel having constant rolling engagement with both pairs'of rollers, whereby rotation of said wheel causes positive'displacement of said lever arm from one of its positions vtothe'other when the wheel is turned, and means on said tiller-bar for turning said wheel.

6. In an outboard motor having a crankshaft, a propeller drive shaft, and a clutch serially arranged between said crankshaft and said drive shaft, the combination of a lever arm operatively connected to said clutch and pivotally supported for swinging movement between clutch-engaged position and clutch-disengaged position, an eccentric wheel journalled on said'lever arm, two pairs of angularly spaced'rollers journalled on said outboard motor on opposite sides of the axis of said eccentric wheel, the periphery of said wheel having constant rolling engagement with both pairs of rollers, whereby rotation of said wheel causes positive displacement of said'lever arm from one of its positions to the other when I the 'wheel is turned; and a control handle operaclutch-disengaged position, an eccentric wheel journalled on said lever arm, said wheel having rolling engagement on its periphery with at least one roller journalled on said outboard motor whereby rotation of the wheel causes said lever arm to move from one of its positions to the other, a handle movably mounted on said tiller bar, and means connecting said handle with said eccentric wheel for rotating the latter when the handle is moved.

4. In anoutboard motor having a crankshaft, a propeller drive shaft, and means for securing said outboard motor to a boat and providing for pivotal movement of the outboard motor about a substantially vertical axis, the combination of a clutch serially arranged between said crankshaft and said drive shaft, a tiller bar connected .to said outboard motor for turning the same to steer the boat, a lever arm operatively connected to said clutch and pivotally supported for swingtively "connected to said eccentric wheel for turning the same.

7In an outboard motor having a crankshaft, a propeller drive shaft coaxial with the crankshaft, and a clutch serially arranged between said crankshaft and said drive shaft, said clutch comprising arr-inverted cup-shaped driver having a non-"rotatable sliding connection with said crankshaft, a companionate driven member slidabl and non-rota-tably connected withsaid drive shaft, said driven member being disposed within and engaging the inner surface ofsaid driver, an anti-friction radial and thrust bearing having one race thereof fixedly mounted on said drive shaft, said driver being fixedly mounted on the other race of said bearing, a spring bearing at one end on said driven member and urging the latter into engagement with said driver, said spring bearing at its other against a shoulder on said drive shaft to transmit its thrust thereto, and means engageable with said driven member to move the latter out of engagement with said Number driver against the thrust of said spring. 1,733,361 ELDON M. WILSON. 1,857,636 LATHAM POLLOCK. 1,933,481 5 2,059,935 REFERENCES CITED 2,09 04. The following references are of record in the 2,155,112 file of this patent: UNITED STATES PATENTS 10 2,342,446 Number Name Date 413,569 Sherman Oct. 22, 1889 1,371,251 Larson Mar. 15, 1921 Number 1,382,955 Clementson June 28, 1921 282,058 1,683,893 Irgens Sept. 11, 1928 15 Name Date .Rice Oct. 29, 1929 I-Ieide May 10, 1932 Mathias Oct. 31, 1933 Eason Nov. 3, 1936 Bowden Sept..7, 1937 Anderson Apr. 18, 1939 Contoni Aug. 26, 1941 Blankshain Oct. 21, 1941 Beaven Feb. 22, 1944 FOREIGN PATENTS Country Date Germany Feb. 12, 1915