US2979019A

US2979019A - Outboard marine drive

Info

Publication number: US2979019A
Application number: US731926A
Authority: US
Inventors: Lyman O Leavitt; Pitt Donald
Original assignee: Anchor Boat & Steel Co
Current assignee: Anchor Boat & Steel Co
Priority date: 1958-04-30
Filing date: 1958-04-30
Publication date: 1961-04-11
Anticipated expiration: 1978-04-11

Description

INVENTORS Zeal 611' Donald Pitt BY L. O. LEAVITT ETAL OUTBOARD MARINE DRIVE Filed April 30, 1958 April 11, 1961 Man/2, L iddy, Daniels & Marc/ ATTORVEYS United States Patent 9 OUTBOARD MARINE DRIVE Lyman 0. Leavitt and Donald -Pitt,'Salt Lake City, Utah, asslgnorsto Anchor Boat & Steel 430., Salt Lake City, Utah, a corporation of Utah Filed Apr. 30, 19158, Ser. No. 731,926

1 Claim. (Cl. 115-34) This invention relates to marine drives .as adapted for small boats and launches, and ,moreparticularly to outboard-type drives for use with inboard engines.

An object of the present invention is to provide a novel and improved, outboard-type screw or propeller drive mechanism for use with an inboardengine, said drive having a quiet, powerful and reliable belt type of transmission extending below the water line and characterized by greatly reduced drag and resistance which is offered to thepassage of water past the hull and drive mechanism.

In the specific illustrated embodiment of the invention the power transfer is accomplished by a toothed beltof the type commonly used for automotive timing drives, and in accomplishing the above object we provide anovel housing for enclosing the said belt, consisting of two vertically extending spaced hollow legs which contain and house respectively the ascending and descending portions of the belt drive. Between the spaced housing legs a passage .of relatively large area exists, through which water may flow freely and with but .little resistance, thereby greatly reducing the drag of the-drive housing. In conjunction with such housing we further ,provide .ahollow screw or .propeller shaft carrying the pulley for the driving belt, said shaft .by virtue of its hollow construction permitting thepassage of .water therethrough, thus further decreasing the resistance or drag of the drive. mechanism.

A further object of the present inventionis to provide a novel and improved propeller mounting and torqueimparting means, in conjunction with the .said hollow propeller shaft,.by which the propeller is normally driven without slippage for movingthe boat through the water, yet if the propeller should strike an object while being driven, it may immediately .halt in its iturningor slow down 'as required, while the. engine and remainderof .the drive mechanism continue delivering ;power, thereby sto prevent damage to the propeller.

A feature of the invention resides in the provision of improved outboard drive meanscharacterized by minimum drag, and improved propeller 'torque imparting means as above characterized, which are extremely simple in construction, reliable in operation and economical to fabricate.

Other features and advantages will hereinafter appear.

In the drawings accompanying this specification, similar characters of reference are used to designate like components throughout the several views, in which:

Figure 1 is a side elevational view of a small boat or launch, having the improved outboard drive of the invention attached to it.

Fig. 2 is a fragmentary rear elevational view of the outboard drive structure which is incorporated in the boat shown in Fig. 1.

Fig. 3 is a side elevational view of the outboard drive structure of Fig. 2.

Fig. 4 is a fragmentary exploded view of the pulley and belt drive components utilized in the outboard drive of the present invention.

Fig. 5 is a fragmentary axial sectional view of the propellershaft and yieldable friction drive between the propeller hub and shaft, as,provided by the invention.

Fig. 6 is a'fragmentary axial sectional .view showing a .universal joint type of driving coupling or connection, as provided :between the inboard engine and the outboard .drive of the present invention.

Referring first to Fig. 1 there is shown a usual type of small boat having a hull 10 in the stern of which there is mounted an inboard marine engine 12. The engine 12 has a splined hollow drive member 13 extending rearwardthrough a suitable opening in the stern of the hull 10. 'Carriedby the drive shaft 13 is a universal joint or driving connection 15, Fig. 6, which has a splined output shaft .17 adapted to :be received in a hollow jack shflt 18 disposed within an outboard drive housing, specifically an .upperhousingportion .19. The universal joint or driving rconnection .15 may also have a splined input shaft 26, .Fig. '6,-a'dapted :to be receivedvin the drive member 13 carried; by the engine "12.

.According to thepresent invention we provide a novel ;andzimproved outboard drive mechanism of the type employing an endless belt'or-chain, and in conjunction therewith providea uniquethousing means, including a lower :housingzportion.indicated at 22 in Figs. 1, 2 and 3, said :housing portion being-especially arranged to enclose the driving belt or chain while at the same time providing .a rminirnumdrag or-resistance to the fiow of water past the thrill Iii.

:Referring ,to Figs. 2-4, the upper housing portion 19 .mounts the hollowjack shaft 18 on suitable bearings (not rshown). The shaft 18 carries apulley or sprocket 24 of the type .adaptedto mesh with a timing belt 25 of conventional design or structure. The lower housing portion 22 of: the :outboard drive carries a propeller shaft 26 in suitable bearings (not shown), such propellershaft also having 'a pulley :or sprocket wheel 27 adapted to mesh -withthe timing'belt 25.

.Referring"particularly to Fig.2, the improved housing construction also includes an intermediate housing portion constituted of -a pair of vertically extending, spaced hol- .low legs .28 ,and29, through which the ascending and descending portions of the timing belt or chain 25 pass in traveling-between thepulleys or sprockets 2.4 and 27.

Disposed between the lower extremities of the hollow legs28 and 29 is the circular or cylindrical lower housing portion 22, having ;a forward extension 31 in which the propeller shaft 26 isdisposed, together with the bearings for such shaft. The spaces within the hollow legs 28 and '29communicate withzthe interior of the cylindrical housing =portionsl22, as will be readily understood, for the -purpose:of .permittingpassage of'the driving belt or chain 125. Theilegsi28;and.29 are watertight, as are the joints where-they attachrtothe upperjhousing portion 19 and the lower housing portion 22. It will be understood that where the propeller shaft 26 extends forwardly out of the cylindrical housing portion 31 a suitable packing and sealing arrangement is provided, in conjunction with the forward bearing for the propeller shaft, thereby to prevent entrance of water into the housing, where such water might come in contact with the driving timing chain 25 and lower sprocket 27.

Further, in accordance with the present invention, the propeller shaft 26 is made hollow and has an appreciable diameter, thereby to permit the passage of water through the propeller shaft and through the hub 33 of the propeller or screw 34 which is carried on the forward extremity of the shaft 26. Thus, the propeller hub 33 and the shaft 26 provide a minim-um of resistance to the flow of water past the hull 10, and also the same is true of the lower housing portion 22 and intermediate housing portion of the outboard drive, since a relatively large space 36 exists e 3 between the depending hollow legs 28 and 29 through which space water may flow with only slight impedance. Further, in accordance with the present invention, we

'provide a novel torque-transmitting device between the hub 33 of the propeller 34 and the propeller shaft 26,

said device normally driving the propeller at its proper rate of speed to propel the boat forwardly, but permaterial such as resilient and flexible rubber or rubberlike substance.

The friction sleeve 38 is contained within the propeller hub 33 and rests against a rear internal shoulder 40 provided in said hub. At its front end, the friction sleeve 38 is engaged by a nut 41 which is threaded on the propeller shaft 26. The nut 41 has a shoulder 42 adapted to engage the front edge of the propeller 33, and

the propeller shaft 26 has an annular external shoulder 44 engaging the rear of the hub 33, thereby to securely retain the propeller 34 on the shaft 26 while at the same time permitting a controlled slippage of the propeller when it strikes an object in the water.

By regulating the nut 44, the amount of compression existing in the rubber sleeve 38 may be varied, thereby to vary the friction between the propeller 34 and the shaft 26, and such friction is adjusted so that normally it is great enough to cause a proper driving of the propeller during normal operation of the boat and engine, yet not so great that the propeller cannot slip and come completely to a stop when it strikes an object in the water, even though the engine and the drive shafts connected thereto continue to turn. Thus, the propeller 34 is protected at all times by this frictional drive which permits slippage under abnormal conditions, and this is an important feature of the invention.

Moreover, it will be observed that such controlled slippage of the propeller is effected by an extremely simple and inexpensive friction device, comprising the rubber sleeve 38.

Referring to Fig. 6, the universal joint type of coupling includes a bearing 50 for the spline-d shaft 17, said bearing being carried by the upper housing portion 19 of the outboard drive. The universal joint includes a link 51 which is pivotally connected between yokes 52 and 53 respectively secured to the splined shafts 17 and 20. A flexible rubber boot 55 encloses the universal joint 15 and seals the same against entrance of water and other foreign matter.

It will now be readily understood that by the foregoing and in accordance with the invention we have provided a novel and unique, quiet yet powerful and reliable outboard drive means for small boats, launches and the like,

the said drive means being characterized by an extremely smooth action as effected by the use of a timing chain or similar belt type of drive, and being further characterized by presenting a minimum of resistance to the flow of water past the hull 10. Such minimum resistance is effected by the unique hollow-leg design of the intermediate portions 28 and 29 of the outboard drive housing, in conjunction with the hollow construction of the shaft 26. Moreover, in conjunction with such structure we further provide a novel friction mounting for the propeller 34, which permits the propeller to slip and come to a complete standstill if it should strike an immovable object while turning in the water, even though the engine and the accompanying drive shafts continue to rotate at normal speeds.

The above structures as provided by the invention are extremely simple and economical to fabricate while at the same time providing for great reliability and flexibility in .below the said upper portion, and an intermediate connecting portion between said upper and lower portions;

a drive wheel disposed in said upper housing portion at a point above the water line of the housing; a propeller shaft and driven wheel disposed in said lower housing portion at a point below the water line of the housing, said propeller shaft having an appreciable diameter and being hollow with open ends thereby to permit the passage of water. through the center of the propeller shafts; a belt extending between and passing around said wheels, said intermediate housing portion comprising a pair of spaced,

slender, hollow members extending vertically between the upper and lower housing portions and enclosing respectively the ascending and descending portions of the belt, the space between said hollow members being free of obstruction from front to rear, thereby to make possible the unimpeded passage of water between the members.

References Cited in the file of this patent UNITED STATES PATENTS 1,845,712 Jacques Feb. 16, 1932 2,679,909 Kiekhaefer June 1, 1954 2,722,193 Brindley Nov. 1, 1955 2,751,987 Kiekhaefer June 26, 1956 2,809,605 Russell Oct. 15, 1957 FOREIGN PATENTS 311,674 Great Britain May 10, 1929