US3653270A

US3653270A - Tilting and trimming arrangement for a tiltable outboard propeller housing for a boat

Info

Publication number: US3653270A
Application number: US52951A
Authority: US
Inventors: Karl Abdon Bergstedt
Original assignee: Volvo Penta AB
Current assignee: Volvo Penta AB
Priority date: 1970-07-07
Filing date: 1970-07-07
Publication date: 1972-04-04
Anticipated expiration: 1989-04-04

Abstract

An electro-mechanical trimming and tilting arrangement for an outboard propeller housing for a boat in which a linkage system couples a jack screw mechanism operated by a reversible electric motor to the tiltable propeller housing. The jack screw mechanism is self-aligning by being mounted by a ball and socket and includes a worm drive between the motor and a rotatable nut which screws a threaded rod up and down through the nut. The nut is caged in operative position by spring loaded detents which yield to release the nut and thereby permit the propeller housing to kick up upon meeting an obstruction. Yieldable flaps are swingable into position to restrain the detents during reverse operation of the propeller to prevent kick-up when backing down. The rod is provided with threads of differing pitch according to the first embodiment, or the nut and rod are provided with a recirculating ball screw connection according to a modification, whereby trim adjustments to the outboard housing are accomplished slowly and tilting movement is accomplished rapidly. The worm connection acts to prevent rotation of the nut by the forces imposed by the propeller reaction whereby the mechanism retains the housing in the position into which it is adjusted by operating the motor. A dog clutch or cone clutch connects the nut to a worm wheel to disconnect the nut from the motor when the nut escapes from the detents.

Description

United States Patent Bergstedt [151 3,653,270 1 Apr .4, 1972 [54] TILTING AND TRIMMING ARRANGEMENT FOR A TILTABLE OUTBOARD PROPELLER HOUSING FOR A BOAT [72] Inventor:

[52] U.S. Cl. ..74/89.l5, 115/41 R, 248/4 [51] ..B63h l/14, B63h 5/06 [58] Field ofSearch ..74/89.15; 115/41; 248/4 [56] References Cited UNITED STATES PATENTS 3,191,573 6/1965 l-lixon ..115/41 2,809,605 10/1957 Russell... 115/41 2,973,738 3/1961 Ladewig.... ...115/41 3,382.839 5/1968 Kiekhaefer ..115/41 Primary Examiner-William F. O'Dca Assistant ExaminerP. D. Ferguson Att0rneyGeorge H. Baldwin and Arthur G. Yeager [57] ABSTRACT An electro-mechanical trimming and tilting arrangement for an outboard propeller housing for a boat in which a linkage system couples a jack screw' mechanism operated by a reversible electric motor to the tiltable propeller housing. The jack screw mechanism is self-aligning by being mounted by a ball and socket and includes a worm drive between the motor and a rotatable nut which screws a threaded rod up and down through the nut. The nut is caged in operative position by spring loaded detents which yield to release the nut and thereby permit the propeller housing to kick up upon meeting an obstruction. Yieldable flaps are swingable into position to restrain the detents during reverse operation of the propeller to prevent kick-up when backing down. The rod is provided with threads of differing pitch according to the first embodiment, or the nut and rod are provided with a recirculating ball screw connection according to a modification, whereby trim adjustments to the outboard housing are accomplished slowly and tilting movement is accomplished rapidly. The worm con- 23 Claims, 3 Drawing Figures PATENTEDAPR M972 3,653,270

sum 1 OF 3 INVENTOR liar! fla'mBe/ysfm'f TTORNEY SHEET 3 [IF 3 INVENTOR Karl 416d: Berysfedf ATTORNEY FATENTED R 4 I972 III/Il .1 I I n TILTING AND TRIMMING ARRANGEMENT FOR A TILTABLE OUTBOARD lROPELLER HOUSING FOR A BOAT The invention relates to a mechanical tilting and trimming arrangements in boats with propeller housing hingeable upward. The arrangement is herein illustrated and described as embodied in a boat drive in which the drive motor is mounted inward and has its drive shaft connected into a propeller housing carried by and disposed rearwardly of the stern transom, the outboard housing being tiltable or hingeable upward on a substantially horizontal transverse axis, and also swingable or rotatable on an upright axis for the steering of the boat. The requirements of tilting and trimming systems vary, however, between different arrangements of drive systems, and with the horsepower of the drive. Hydraulic systems may be excessively complex and expensive for certain applications, and in many cases conflicting requirements are difficult to meet with hydraulic systems. For example, it is usually desirable that the propeller housing should tilt up upon striking an underwater object, but that it should be held against tilting when the propeller is operated in reverse. It is usually desirable that the propeller housing, or outboard leg, should be maintainable in a partially tilted position to permit operation in shallow water. It is usually desirable that means he provided to slowly adjust the trim of the outboard leg during operation from the remote steering station of the boat and that such means be also operable to rapidly tilt the leg into fully raised non-operating position when desired, for example, to permit inspection or replacement of the propeller, or to tilt the leg out of water for storage. Electrical remote control of the tilting and trimming system may be preferred in many instances to remote hydraulic control since electrical wiring is more flexible and cheaper than hydraulic lines. Moreover, since battery power is usually available for other purposes, a saving in cost may be realized if a hydraulic system is omitted.

The electro-mechanical system of the present invention may be disassembled for repair and reassembled by a mechanic using simple tools, whereas hydraulic systems may require hydraulic technicians and more sophisticated tools and equipment. The arrangement described herein is simple, sturdy and reliable in operation, and provides slow trim angle adjustment for the leg, effective maintenance of the selected trim angle during operation of the drive, rapid power tilting of the leg, readily adjustable resistance to initial tilting of the leg upon striking an underwater or floating object, convenient automatic means for locking the leg against tilting during reverse operation of the propeller, electrical remote control, as well as compact and convenient installation and adaptability to various designs and arrangements of inboard-outboard and outboard motor propulsion equipments.

It is required, accordingly, that the propeller housing during forward movement is to be possible to adjust and lock in various trim positions, but if the propeller housing should strike against a solid obstacle, then of course, it would have to yield and swing upward, to return immediately to the starting position after the obstacle has been passed. The propeller housing must not, however, swing up in the event that the drive engine is suddenly, such as by shifting gears into neutral, decoupled when the boat has headway, nor may it be permitted to swing up during reverse propeller rotation, but it must be maintained securely with a force which at least corresponds to the drag or reverse :driving force of the propeller under these circumstances. It is desirable that it should be possible to tilt the propeller housing out of the water for inspection or repair through a large angle, and that such tilting, and tilting through a lesser angle for shallow water operation should be easily and rapidly accomplished with minimal power requirements.

An object of the present invention is to provide an electromechanical tilting and trimming arrangement which fulfills these and other requirements, which is simple and inexpensive, and which is reliable in operation.

The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a side elevational view, partially broken away and in section, of a portion of an inboard-outboard drive unit for a boat embodying the invention;

FIG. 2 is a partially sectioned plan view of the tilting and trimming mechanism of the unit taken generally along line 2- 2 of FIG. 1 and on an enlarged scale; and

FIG. 3 is a side elevational view similar to FIG. 1 showing a modified tilting and trimming mechanism.

As seen in the drawings, the tilting and trimming arrangement is shown as applied to a propeller housing 1 suspended in a known manner on the stern transom 2 by means of a support bracket 3 fixed thereto. Power from an inboard engine may be supplied to the propeller housing through drive shaft housing 40, and through a flexible boot 41 adapted to contain suitable universal joint means. The mounting bracket 3 includes fixed tilt journal pins 4 which carry a yoke or gimbel member 5 for swinging on the horizontal axis of pins 4. The yoke member 5 supportingly carries the propeller housing 1 for swinging on an upright axis under the control of a steering arrangement generally identified at 42, all as shown and described, for example in my US. Pat. No. 3,339,517 issued Sept. 5, 1967 and assigned to the assignee hereof.

The tiltable support yoke 5 carries a fixed pivot pin 6 spaced from but parallel to the tilt axis established by pins 4. A link member 7 is pivotally connected to yoke member 5 by pin 6 at one end and connected by a pin 43 to a lever 8. The lever 8 is pivotally mounted on a fixed pin 9 carried by an arm 10 constituting a fixed portion of mounting bracket 3. Swinging of arm 8 in a clockwise direction about the axis of pin 9 moves the pin 43 generally in the direction of arrow 44, and this movement is transmitted by link 7 to cause pin 6 to move rearwardly, that is, in a direction toward the right in FIG. 1, about the axis of pin 4. Such swinging movement of the lever 8 is accomplished through an arm member 11 rigidly affixed to lever 8 and carrying a pin 45 spaced thereon from the pin 9. The pin 45 connects lever 11 to a longitudinally movable rod 13.

The knee joint

construction including pins

6, 9 and 43, link 7 and lever arm assembly 8, 11 is preferably duplicated on each side of the unit and a cross-bar 12 is arranged to extend from one to the other-of the levers 11 whereby links 7 on each of the yoke member 5 will operate in unison.

The arrangement for bringing about the movement for the propeller housing and for maintaining it in a position into which it may be adjusted consists of a mechanical jack screw construction for moving rod 13 longitudinally. The rod 13 is fixedly attached to a sleeve 14 which extends upwardly therefrom. Rod 13 and sleeve 14 are axially non-rotatable due to the pin connection 45 between rod 13 and lever 11. The sleeve 14 includes an upper end portion 46 which is internally provided with screw threads 16 having a relatively small pitch, and the sleeve is further provided with an inward shoulder 47 spaced between its ends. A rod 17 carrying external threads meshing with threads 16 is disposed partially within sleeve 14 and extends upwardly therefrom through the central opening 48 of a mounting ball 15 and thence upwardly into an upper housing 20 which is mounted securely and fixedly to the ball 15. The sleeve 14 is arranged in a sliding fit within a depending tubular skirt portion 49 of ball member 15. The ball member 15 is rockable through a small angle in its hollow spherical socket 50 about an axis parallel to the pin 45 thereby to allow for and adjust itself to the movement of pin 45 toward the right as viewed in FIG. 1 as the lever 11 swings on the axis of pin 9. The socket is preferably lined with hollow rubber hemispherical cups 51 to absorb vibration and dampen shocks. The ball is non-rotatable about the axis of shaft 17 in socket 50 by virtue of the frictional resistance of the rubber lining, or, if desired, small projections 52 may be provided on the ball to engage in vertically oriented spline grooves formed in the socket to prevent such rotation. Socket 50 is fixed to or formed integrally with support bracket 3.

The rod 17 includes a stop portion 30 positioned to be engaged against the upper end of sleeve 14 for purposes hereinafter described. An oil passage 53 entering through portion 30 extends within rod 17. Rod 17 is provided with external screw threads 18 extending therealong from a point adjacent stop 30 to the extreme upper end of the rod. Threads 18 are of substantially greater pitch than the pitch of threads 16 and they may be double threads. A nut 19 is internally threaded to cooperate with threads 18 and is disposed on the upper portion of the rod which is provided with threads 18.

Rigidly affixed to ball 15 and extending thereabove is the housing 20 which is provided with a worm wheel '21, carried by a ball bearing 54 for rotation co-axially with rod 17. Nut 19 and wheel 21 are positioned with cooperating elements of dog clutch 22 nonnally providing a connection for the rotating of nut 19 in response to rotation of wheel 21. Worm 23 is rotatably carried by housing 20 and is threadedly engaged with the periphery of worm wheel 21.

Rod 17 further includes a downward extension 55 extending through shoulder 47 of sleeve 14 and terminating in a ball bearing lower end head portion 56 adapted during certain circumstances to engage against shoulder 47 as later described.

Referring now additionally to FIG. 0, IT WILL BE SEEN THAT WORM IS connected for rotation by a reversible electrical motor 24, which is also carried on housing 20.

Nut 19 is formed with a conical upwardly directed surface portion or flank 25 against which are normally disposed two oppositely disposed radially outwardly movable detents 26 which are urged inwardly by respective compression springs 27. The conical surface 25 of the nut is so oriented that an upward axial force on nut 19, if of sufficient strength to overcome the force of springs 27, forces the detents outwardly and permits the nut to escape and move upwardly in housing 20.

The detents include rods, such as rod 28, which, upon outward movement of the detents, project outwardly of the housing 20. In order to lock the detents when desired, thereby to prevent the upward escape of nut 19, a pair of swingable flaps 29 are disposed outwardly on housing 20 and these, through a remote cable or push-pull control rod 57, may be operated from the detent retaining position shown into a position free of the rod ends 28. The flaps, however, are of a material which will yield when substantial force is applied, such that if a force is imposed on nut 19 which would be sufficiently great to damage other parts of the mechanism, the flaps will yield outwardly thereby to permit the detents to separate and release the nut. The yielding of he flaps may be by plastic deformation but is preferable resilient yielding with the flaps consisting of strong leaf springs. In operation, while the boat is being propelled forwardly, the propeller pressure urges the housing 1 in a clockwise direction about pivot 4 as seen in FIG. 1, thereby tending to force link 7 forwardly and urging lever 11 to rotate in a direction to lower pin 45. The force is transmitted through rod 13 and sleeve 14 to rod 17 and, the outward shoulder 31 provided at the upper end of rod 17 being in engagement with nut 19, the nut is urged downwardly to maintain dog clutch 22 in driving engagement. Operation of motor 24 with the parts in the positions shown in FIG. 1 will now rotate wheel 21 and, through clutch 22, will rotate nut 19. Because the threads 18 are of substantially greater pitch than the threads 16, such rotation of the nut will screw rod 17 inwardly or outwardly of sleeve 14 on threads 16. If the rod 17 is being screwed into the sleeve 14, the sleeve is caused to rise, thereby raising rod 13 and this motion is transmitted by lever 11, arms 8 and link 7 to yoke 5, thereby to cause the yoke and propeller housing to swing in a counter-clockwise direction on pivot 4. Because of the relatively small pitch of threads 16, this motion takes place slowlyv and trims the angle of the propeller housing to adjust it into desired operating position. While operation of the motor in this direction causes the unit to be trimmed outwardly from the boat, that is toward a tilted position, rotation of the motor in the opposite direction causes pin 7 to move forwardly,

thereby trimming the propeller housing toward the boat. The relatively small pitch of threads 16 makes it unnecessary to provide any locking arrangement to retain the outboard housing in its trim position since upward or downward force transmitted through rod 13 is insufficient, with the motor deenergized,'to cause rotation of rod 17.

If during forward propulsion, the engine is suddenly throttled down, or if it is otherwise disconnected from driving the propeller such as by shifting gears into neutral, the resultant water pressure against the propeller and propeller housing tends to swing the propeller housing toward tilted position, and this tendency urges rod 13 upwardly. Since the dog clutch is engaged, nut 19 is prevented by the drag of the worm and motor from rotating on threads 18, and the compression springs 27 are designed to be of sufficient strength to retain nut 19 against rising in this event, whereby the housing is prevented from such tilting. lf, however the propeller housing should strike a submerged or floating object when the boat is moving forward, the resultant tilting force imposed on the propeller housing may be much greater than is produced by the force of water, and, to prevent damage to the outboard leg or other parts of the drive unit, the springs are arranged to yield under such excessive forces. Accordingly, the detents 26 will be forced outwardly by the conical surface 25 and will thus release the nut and permit the necessary upward movement of rods 17 and 13 until the obstruction has been cleared. When the obstruction is cleared, the propeller housing will return toward its upright position, either by gravity or by the driving force of the rotating propeller, or tooth, and it will be seen that as it nears its upright trim position, the nut 19 will be brought down onto the detents. The detents are formed with upper and lower camming surfaces, and the descending nut will force the detents apart to permit the nut again to return to its normal operating position with its surface 25 caged under the detents. The force of the springs which must be overcome as the nut passes downwardly between the detents tends to cushion the shock just before the unit reaches its trim position.

When the engine is driving the propeller in reverse, the tendency of the propeller housing to tilt may be sufficient to overcome the detent springs. To prevent the escape of nut 19 during reverse operation, the flaps 29 are operated by control rod or cable 57 into the positions shown in FIGS. 1 and 2 to cause the pins 28 of the detents to be restrained against outward movement. It is desirable that the cable or push-pull rod 57 be connected to the reverse gear control, so that whenever the engine is connected in reverse, the flaps are simultaneously and automatically moved into the detent retaining position, but that when the gears are in neutral or forward drive position, the flaps are automatically caused to swing into a position out of the way of the pins 28.

As heretofore mentioned, if, for any reason, while the flaps are in detent retaining position, the outboard propeller housing is forced to tilt, the flaps are designed to yield and thereby permit the nut to escape beyond the detents before any damage is done to the system.

It is frequently desired to tilt the propeller housing completely out of water, as, for example, when it may be desired to remove the boat from the water, or to inspect, replace or remove weeds from the propeller. To accomplish such tilting, the electric motor 24 is operated in the direction to screw rod 17 into sleeve 14 until the sleeve engages against upper shoulder 30. The rearward tilting of the unit occurs relatively slowly during this part of the operation, but after sleeve 14 has engaged shoulder 30, the further operation of the motorcan no longer rotate shaft 17, and the continued rotation of nut 19 screws rod 17 upwardly through the nut. Because of the relatively steeper pitch of threads 18, the rod 17 now moves upwardly at a much faster rate, drawing sleeve 14 and pin 45 upwardly and causing rapid movement of the inner end of link 7 in the direction of arrow 44 until the propeller housing has been tilted as far as may be desired or until it is prevented'from further tilting by engagement with rubber bumper 59. Subsequent operation of the motor in the opposite direction first results in the rod or shaft 17 being screwed out of nut 19 until the upp r end shoulder 31 of shaft 17 engages the upper end of the nut. Continued motor operation thereafter causes, at the slower trimming rate, further movement of the propeller housing into its desired trim position for normal operation.

Should the motor 24 be operated in the direction to trim the propeller housing forwardly after it has reached its extreme forward position, the nut 19 will be forced up through the detents thereby to disengage the dog clutch 22, whereby wheel 21 is disengaged from the nut and the motor and worm 23 are permitted to rotate freely. As alimit arrangement, in order to prevent the rod 17 from becoming completely screwed out of sleeve 14, the ball bearing head 56 on the lower end of rod 17 engages internal shoulder 47 of the sleeve and the motor will then be stalled against further operation in the direction tending to swing the propeller housing forwardly.

A modification of my invention is shown in FIG. 3. According to the modification, and identifying the parts thereof which correspond to the parts of the foregoing embodiment by the same numbers with prime symbols added thereto, the ball is fixedly connected to housing and is rockably carried in socket 50'. Unitary depending tubular skirt portion 49 extends downwardly from the ball. A unitary shaft 60 is disposed for axial movement through skirt 49, ball 15 and housing 20' and comprises a lower end portion 13 pinned by pin 45' to lever 11, being coupled by the pin and lever to swing the propeller housing 1 in the manner described above in connection with the first embodiment.

The upper portion 61 of shaft or rod 60 is externally provided with a spiral ball race 62 and extends through a nut 63 internally provided with a cooperating ball race. The ball race of the nut, however, does not open through the upper or lower ends of the nut but is closed off at each end, and a recirculating passageway 64, shown in broken lines, is provided internally of the nut to permit passage of bearing balls 65 from and between one and the other of the ends of its ball race. The bearing balls 65 fill, or substantially fill, the race of the nut and the passageway, whereby as hearing balls reach the upper end of the nut as the result of nut rotation in one direction, they pass through passageway 64 to enter the lower end of the nut race, and, as they reach the lower end of the race as the result of opposite rotation, they pass upwardly through passageway 64 again to enter the face at its upper end.

The races of the nut and shaft are substantially semicircular in cross section and the balls fill the races between the shaft and nut thereby to form a low friction ball bearing screw connection therebetween in a manner known for recirculating ball screw assemblies. A coil compression spring 66 is disposed under the upper end shoulder 67 of shaft 60 and bears against the top of nut 63 to urge the nut downwardly on the shaft.

The lower end of the nut has a conical surface portion 67 cooperative with and conforming to and normally engaged with a conical upper surface portion of a worm wheel 68 thereby to comprise a metal-to-metal cone clutch between the wheel 68 and nut 63, replacing the dog clutch connection of the first embodiment. The wheel 68 is threadedly engaged with a motor driven worm 23' corresponding to worm 23 of the first embodiment.

Nut 63 is normally caged under spring loaded detents 26 corresponding to detents 26 of the first embodiment, although the camming surfaces engaging between the lower surfaces of the detents and upper surface of the nut are preferably more abrupt, that is, are at a lesser angle to a plane perpendicular to the axis of the threaded shaft than are the corresponding surfaces in the first embodimennThe detents 26' are provided with restraining flaps 29 operated by a push-pull rod 57' as in the first embodiment, and it will be understood that elements of the first embodiment not specifically described in the foregoing description of the modified embodiment are similarly provided for the same purposes in the modified embodiment.

Operation of the motor to drive worm 23 causes a corresponding rotation of wheel 68 and nut 63 which, depending upon the direction of rotation, results in the screwing up or down of shaft 60 through the nut. Since the frictional resistance of the ball bearing connection between the nut and shaft is very small, a small motor of low power is sufi'lcient to adjust the trim of the propeller housing even during high power driving of the propeller. During such operation. the force against the propeller is in a direction tending to force shaft 60 downwardly, resulting in firm engagement of the frictional cone clutch between nut 63 and worm wheel 68.

Since it is not ordinarily desired to tilt the propeller housing upwardly when the propeller is being driven, and because of the low friction of the recirculating ball screw connection, it has further been found that a small low power motion is sufficient to tilt the propeller housing at an acceptable and reasonably rapid rate even though the pitch of the race 62 is much less than the pitch of threads 18 of the first embodiment. Trim adjustment while full power or cruising power is being applied to the propeller will be, assuming the motor speed to vary with load, at a low rate, while tilting with no power being supplied to the propeller will be at a much faster rate.

Reverse operation of the propeller tends to force shaft 60 and nut 63 upwardly, and to prevent the nut from escaping as a result thereof, flaps 29 are swung into position to restrain the detents as in the first embodiment.

If the propeller housing strikes an underwater or floating object during forward movement of the boat, the nut is forced through the detents, camming them outwardly as it passes. Spring 66 then operates to spin the nut down on shaft 60 until it emgages the upper cam surfaces of the detents if it has risen above them, and on the return of the leg, after clearing the obstacle, the nut passes down between the detents but stops the forward movement of the propeller housing at a more tilted position than its original trim position, thereby desirably limiting the length of the return stroke of the housing and lessening the impact. The motor is thereafter operated to return the propeller housing to desired trim position.

While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.

What is claimed as new and what it is desired to secure by Letters Patent of the United States is:

1. In a boat drive arrangement including an outboard propeller housing tiltably mounted on a horizontal tilt axis to a non-tiltable support member and a device for controlling the movement of said housing about said axis, said device spanning said axis and including hollow body means and rod means extending into and movable with respect to said body means and said device being provided with a connection between one of said means and said propeller housing and a second connection between the other of said means and said support member, said device being characterized in that said rod means has a threaded portion thereof disposed in said body means, a threaded element is provided disposed in said body means having threads operatively in mesh with said threaded portion of said rod means, means are provided for imparting relative rotation between said element and rod means screwingly to move said rod means axially with respect to said element, and said body means is provided with yieldable detent means for releasably retaining said element in predetermined position in said body means.

2. The combination according to claim 1 in which said device is further characterized in that it is provided with selectively operable locking means for locking said detent means against yielding thereby to prevent release of said element.

3. The combination according to claim 2 wherein said means for imparting rotation comprises means for rotating said threaded element, said rod means comprises a rod element connected and restrained against rotation by one of said connections, said body means is connected and restrained againstrotation about the axis of said threaded portion by the other of said connections, said threaded portion of said rod means extends longitudinally of said rod element away from said connection thereof and is threadedly connected to said rod element by threads of a pitch less than the pitch of said threads of said threaded element.

4. In a device for controlling the tilting movement of an outboard propeller housing mounted to a boat on a horizontal tilt axis, said device spanning said axis and comprising a rod member and a hollow body member, one of said members being coupled to said housing and the other being coupled to a support member for said housing which is non-tiltable with respect to said boat, said rod member telescopingly entering and having a threaded portion within said body member, a nut within said body member threadedly engaged on said threaded portion, a clutch element mounted for rotation in said body member, clutching means on said nut clutchingly engageable with said clutch element, said rod element and body member being subject to forces urging said rod element inwardly and outwardly of said body member in accord with the direction of external forces tending to move said leg on said tilt axis, and

said nut and clutching means being urged toward and away from said clutch element and correspondingly into and out of drive'engagement therewith in accord with the direction in whichfo'rc es are applied thereto from such external forces on said'propeller housing, and means engaging said clutch element for retarding rotation thereof.

5. The combination according to claim 4 wherein said means for retarding rotation includes selectively controllable means for rotating said nut.

6. The combination according to claim 4 wherein said clutching means on said nut comprises a cone clutch face thereon and said clutch element includes a cone clutch face for engagement therewith.

7. The combination according to claim 4 wherein said clutching means on said 'nut and said clutch element comprise dog clutch elements.

8. The combination according to claim 4 wherein said nut includes recirculating anti-friction balls engaging in the threads of said threaded portion.

9. The combination according to claim 4 wherein said clutch element is provided with gear teeth and said means engaging said clutch element for retarding rotation thereof includes a gear member engaged with said gear teeth.

10. The combination according to claim 9 and a reversible motor for rotating said gear member.

11. The combination according to claim 4 and yieldable nut engageable detent means for releasably retaining said nut in predetermined position in said body member.

12. The combination according to claim 4 in which said one of said members is coupled to said housing by means comprising a bell crank lever pivotally mounted at its fulcrum to said support member, one arm of said bell crank lever being operatively connected to said one of said members and the other arm of said bell crank lever being operatively connected to said housing.

13. The combination according to claim 12 in which said non-tiltable support member comprises a mounting bracket fixed to the boat and including horizontal axis pivot means, a tiltable gimbal member is supported on said pivot means, said housing is swingably mounted on said gimbal member, and a link connects said other arm of said bell crank lever to said gimbal member.

14. The combination according to claim 4 wherein the coupling between said other member and said support member is provided by means of a ball portion on said other member and a hollow socket on said support member housing said ball portion, the orientation of said device with respect to said support member being self-adjusting with rotation of said ball portion in said socket.

15. The combination according to claim 14 wherein said ball portion is integral with said body member, said body member has a longitudinal axis and is internally generally cylindrical about said axis and said ball portion, said socket, said rod member and said body member are coaxially aligned.

16. In combination in a boat drive arrangement including a mounting member and an outboard drive leg assembly mounted on said member for tilting on a horizontal tilt axis, a bell crank having its fulcrum pivotal on said member offset from said tilt axis and one arm linked to said assembly offset from said tilt axis, a tilt control device comprising a body supportedly connected to said member and extensible rod means, said rod means including two axially aligned elements, each of said elements having a spirally threaded portion and said elements being threadedly connected by engagement thereof, means for restraining one of said elements against axial rotation and for connecting it to the other arm of said bell crank, the other of said elements having a second spirally threaded portion, rotatable means carried by said body including a spirally threaded portion threadedly engaged with said second portion of said other element, means for rotating said rotatable means about the axis of its said threaded portion, and means for limiting the progression of one of said threaded portions along the other of said threaded portions with which it is so engaged.

17. The combination according to claim 16 wherein said one and said other engaged threaded portions are of less pitch than the other pair of engaged threaded portions.

18. The combination according to claim 17 wherein said one and said other of said threaded portions are the engaged threaded portions of said elements.

19. The combination according to claim 16 wherein said body is provided with spring-loaded detent means engageable with said rotatable means for releasably retaining said rotatable means in predetermined position in said body.

20. In combination in a boat drive arrangement including a mounting member and an outboard drive leg assembly mounted on said member for tilting on a horizontal tilt axis, a tilt control device comprising a body supportedly connected to said mounting member and threaded means extensible from said body, said means including two elements having respective coaxial spirally threaded portions and being threadedly connected by engagement of said portions, means for restraining one of said elements against axial rotation and for connecting said one element to said leg assembly, the other of said elements having a second spirally threaded portion coaxial with the first said threaded portion thereof, screw means carried by said body and including a respective spirally threaded portion threadedly engaged with said second threaded portion of said other element, said body comprising means to rotate said screw means, and means to limit the progression of one of said threaded portions along the other of said spirally threaded portions with which it is so engaged.

21. The combination according to claim 20 wherein said one and said other of said spirally threaded portions have threads of less pitch than the pitch of the threads of the other pair of said engaged threaded portions.

22. In combination in a boat drive arrangement including a mounting member and an outboard drive leg assembly mounted on said member for tilting on a horizontal tilt axis, a bell crank disposed below said tilt axis and having its fulcrum pivotal on said member below said tilt axis, said bell crank having two arms, a link pivotally connected at one end to one of said arms and pivotally connected at its other end to said leg assembly below said tilt axis, and an elongated, upright tilt control device comprising a body supportedly connected to said member and extensible rod means extending downwardly from said body, said body comprising means for longitudinally moving said rod means, the lower end of said rod means being pivotally connected to the other arm of said bell crank.

23. The combination according to claim 22 wherein, when said leg assembly is in normal drive position, said one arm extends upwardly from said fulcrum said said other arm extends rod means upwardly.

UNITED STATES RATENT OFFICE CERTIFICATE OF CORRECTION 3,653,270 April 4, 1972 Patent No. Dated Inven tor(s) Karl Abdon' Bergstedt It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 25, "FIG. 0" should read FIG. 2 Column 3, line 26, the reference numeral "00" should read -23-- Signed and sealed this 31st day of October 1972.

(SEAL) Attest:

' EDWARD M.FLETCHER,JR. ROBERT GOT'ISCHALK Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) UscoMM-Dc 375. 5

at us GOVERNMENT PRINTING OFFICE: I969 O-356334

Claims

1. In a boat drive arrangement including an outboard propeller housing tiltably mounted on a horizontal tilt axis to a nontiltable support member and a device for controlling the movement of said housing about said axis, said device spanning said axis and including hollow body means and rod means extending into and movable with respect to said body means and said device being provided with a connection between one of said means and said propeller housing and a second connection between the other of said means and said support member, said device being characterized in that said rod means has a threaded portion thereof disposed in said body means, a threaded element is provided disposed in said body means having threads operatively in mesh with said threaded portion of said rod means, means are provided for imparting relative rotation between said element and rod means screwingly to move said rod means axially with respect to said element, and said body means is provided with yieldable detent means for releasably retaining said element in predetermined position in said body means.

3. The combination according to claim 2 wherein said means for imparting rotation comprises means for rotating said threaded element, said rod means comprises a rod element connected and restrained aGainst rotation by one of said connections, said body means is connected and restrained against rotation about the axis of said threaded portion by the other of said connections, said threaded portion of said rod means extends longitudinally of said rod element away from said connection thereof and is threadedly connected to said rod element by threads of a pitch less than the pitch of said threads of said threaded element.

4. In a device for controlling the tilting movement of an outboard propeller housing mounted to a boat on a horizontal tilt axis, said device spanning said axis and comprising a rod member and a hollow body member, one of said members being coupled to said housing and the other being coupled to a support member for said housing which is non-tiltable with respect to said boat, said rod member telescopingly entering and having a threaded portion within said body member, a nut within said body member threadedly engaged on said threaded portion, a clutch element mounted for rotation in said body member, clutching means on said nut clutchingly engageable with said clutch element, said rod element and body member being subject to forces urging said rod element inwardly and outwardly of said body member in accord with the direction of external forces tending to move said leg on said tilt axis, and said nut and clutching means being urged toward and away from said clutch element and correspondingly into and out of drive engagement therewith in accord with the direction in which forces are applied thereto from such external forces on said propeller housing, and means engaging said clutch element for retarding rotation thereof.

7. The combination according to claim 4 wherein said clutching means on said nut and said clutch element comprise dog clutch elements.

23. The combination according to claim 22 whereiN, when said leg assembly is in normal drive position, said one arm extends upwardly from said fulcrum said said other arm extends forwardly from said fulcrum, and wherein said means for moving said rod means comprises power means for moving said rod means upwardly.