US3416483A

US3416483A - Brake mechanism for tiltable propeller units

Info

Publication number: US3416483A
Application number: US602820A
Authority: US
Inventors: Bergstedt Karl Abdon
Original assignee: PENTA AB
Current assignee: PENTA AB
Priority date: 1965-12-22
Filing date: 1966-12-19
Publication date: 1968-12-17
Anticipated expiration: 1985-12-17

Description

Dec. 17, 1968 K. A. BERGSTEDT BRAKE MECHANISM FOR TILTABLE PROPELLER UNITS 3 Sheets-Sheet 1 Filed Dec. 19, 1966 I mvsmon KARL ABm/v Bmesrwr yii ywk ATTORNEY 17, 1963 K. A. BERGSTEDT 3,416,483

BRAKE MECHANISM FOR TILTABLE PROPELLER UNITS Filed Dec. 19, 1966 v 5 Sheets-Sheet 2 INVENTOR hA RL ABDONBERGSTEDT Dec. 17, 1968 K. A. BERGSTEDT 3,416,483

, BRAKE MECHANISM FOR TILTABLE PROPELLER UNITS Filed Dec. 19, 1966 3 Sheets-Sheet 3 FIG. 3

3 v 2d 16 14 15 1 17 3 a;

(u mul V v 3L HQJLL.

United States Patent 3,416,483 BRAKE MECHANISM FOR TILTABLE PROPELLER UNITS Karl Abdon Bergstedt, Goteborg, Sweden, assignor to AB Penta, Goteborg, Sweden Filed Dec. 19, 1966, Ser. No. 602,820 Claims priority, application Sweden, Dec. 22, 1965, 16,680/ 65 7 Claims. (Cl. 115-41) A boat drive arrangement including a tilting outboard power leg and having a brake comprising a drum and friction band, the drum being coaxial with the tilt axis of the outboard power leg and the brake restraining tilting movement of the leg.

In those drive arrangements for boats which consist of an outboard power leg or propeller unit mounted in the stern of the boat and which may be coupled to an inboard engine, for example, the outboard unit is preferably tiltable so as not to be damaged in case of running aground. In normal forward operation, the propeller thrust keeps the unit in operating position, so that it may be freely pivoted, but it must nevertheless be retained in this position with enough force so that the propeller housing when throttling down in motion will not be shifted up because of the resistance of the water. If in that case the motor is accelerated again before the boat has stopped, the partly tilted propeller unit will strike against the abutment on the boat with great force, which may cause damage. The same may occur whenever the outboard leg re- Q turns from the fully or partially tilted position, particularly when power is 'being applied to the propeller for forward drive. In reverse operation, it is necessary to lock the pivoting motion, as the propeller thrust will tend to swing the unit upward.

It has been known to lock the outboard leg of a boat drive with a hook or the like to secure the leg positively against tilting for reverse operation but with less effort in forward operation such that the restraint of the hook or latch is overcome when the leg strikes an underwater object. This locking device has the disadvantage that as soon as the hook is released, the propeller unit can swing freely and may be damaged either when abruptly stopped as it reaches its maximum tilt position or when it swings back into operating position under the thrust of the propeller.

The present invention relates to an arrangement by means of which both the upward and the downward tilt can be braked at will, while at the same time the leg may be effectively locked in normal operating position while driving the boat in reverse, i.e. while backing down, and may also be restrained or locked in any intermediate partially tilted position. The characteristic feature of the invention is a brake drum arranged coaxially with the tilt pivot of the outboard leg to cooperate with a brake band of which the reaction is transmitted to a part fixed with respect to the boat.

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 drawing, in which:

FIG. 1 shows a side view of the stern of the boat with an inboard-outboard power leg (a propeller unit) provided with a brake mechanism according to the invention,

FIG. 2 shows a lengthwise section of a transmission case belonging to the propeller unit in FIG. 1,

FIG. 3 is a fragmentary sectional view taken generally ice along line 33 of FIG. 1 on an enlarged scale showing details of portions of the brake mechanism, and

FIG. 4 is a fragmentary side view on an enlarged scale of a portion of the mechanism as seen in FIG. 1 with parts in position corresponding to operation of the drive in reverse gear.

In the stern transom 1 of boat 40 there is an opening 2 covered by a shield 3. The shield 3 carries bearings 4 disposed forwardly of the shield, that is, within the boat and these hearings mount a transmission case 5 freely rotatable on an axis of rotation which is horizontal and parallel to the stern transom 1. The shield 3 is provided with an opening 30 for an intermediate shaft 6 for driving a propeller. The shaft 6 is enclosed in the outboard housing or leg 7 which mounts the propeller, as shown, for example, in my application entitled Drive Arrangement for Motor Boats, filed Nov. 29, 1966, Ser. No. 597,769. The intermediate propeller drive shaft 6 is supported for rotation in the transmission case 5, and as the propeller housing or outboard leg swings in a vertical plane, i.e. when it tilts on the aforesaid axis, the transmission case rotates on its bearings 4. At one end of the transmission case, an input shaft 8 is mounted in bearings 31 in such manner as to be coaxial with the geometrical axis of rotation of the transmission case 5, and the shaft 8 is connected by a belt sheave 9 or the like to a motor, not shown, set up in the boat. The shaft 8 is connected in known manner by double bevel gears to the intermediate shaft 5 for forward and reverse operation, for example, as shOWn in my US. Patent No. 3,269,497. At the opposite end of the transmission case 5 there is an operating means 10 for the clutch 32 of the transmission and on the end 33 of the transmission case is a cylindrical braking surface or drum 11. The axis of rotation of surface 11 is concentric with the geometrical axis of the transmission case 5. The brake drum 11 is encircled by a double-action friction brake band 12, controlled by a stop member in the form of pin 13 fixed with respect to the boat by attachment to shield 3 by means of socket member 41 and nut 42 both threadedly engaged on the pin.

The brake band is provided at its end with

lugs

14 and 15 having

holes

34 and 35 through which pin 13 extends. The holes a-re large enough to permit pin 13 to slide freely therein. On either side of the

lugs

14, 15, the pin 13 has fixed

stop lands

16, 17. Outside or beyond the stops, the pin 13 is threaded and fitted with

nuts

18, 19, and between each nut and the adjacent lug of the brake band 12, a

coil spring

20, 21 is inserted. The spring compression of each spring can be regulated by drawing up or tightening the

respective nut

18 or 19, thereby to increase the bias against the respective lug. It will be seen that

lands

16 and 17 are arranged outwardly of the lugs, that is, not between the lugs, and that land 16 is disposed behind lugs 14, and land 17 behind lug 15.

The brake mechanism functions as follows. The

nuts

18 and 19 are tightened enough so that the brake band 12 acts with some friction on the brake drum 11. If outboard leg 7 swings up or tilts for any reason, the lug 15 is pressed by the force transmitted through the hand against the stop land 17, while the lug 14 is acted upon by the spring 20 in the same direction. The result is a servo or self-applying brake effect whose force depends on the adjusted spring tension of spring 20. When the propeller housing is lowered, the brake band 12 will turn in the opposite direction, holding leg 14 against the stop land 16, while leg 15, under the action of spring 21 and the friction between the brake drum 11 and the brake band, is shifted to the left in FIG. 1, providing a brake action on the downward swing which is adjustable at will. The adjustment of spring 21 should be sufiiciently tight to prevent an excessive blow against the shock absorbent abutment means 36 when the leg returns to operating position but the adjustment for normal operation should be not so tight as to prevent return of the leg from its tilted position. If the nut 19 is tightened to compress spring 21 sufficiently to cause lug 14 to engage or nearly engage stop 16, the braking action upon the return of the leg from tilted position will be substantially increased, and it will be increased to a greater extent than the braking force resisting tilting, whereas tightening of nut 18 to further compress spring 20, will increase resistance to tilting to a greater extent than it increases resistance to the return movement of the leg. If either or both of

nuts

18 and 19 is tightened, the band may be caused to grip the drum sufiiciently tightly to retain the leg in operation position while backing down, though if one wishes to utilize such adjustments to prevent tilting of the leg during reverse driving of the propeller, less tightening of nut 18 would be required to provide sufi'icient braking action than would be the case, if nut 19 is tightened. Tightening of one or the other or both of

nuts

18 and 19 will permit locking of the leg in any desired angle of tilt, such as for operation in shallow water. If spring 20 were omitted or made ineffective by backing ofi nut 18, the band would have little braking effect as the leg tilts but, under the influence of spring 21, the return movement of the leg from tilted position would be substantially retarded or braked.

For reverse operation, the brake action obtained by tightening nut 18 to compress spring 20, or tightening of both nuts, may be insufficient to retain the outboard leg 7 in operating position, and for this reason a more positive locking means is preferably associated with the brake mechanism, which locking means in the illustrated embodiment is coupled for operation by the control linkage for the reverse gear so that both are actuated simultaneously.

This linkage included in the reverse gear control consists of a rotatable shaft or rod 10 entering into the transmission case 5 through an opening 39 in the center of the brake drum 11, i.e. along the axis of rotation of the transmission case, rotation of the shaft being effected by a lever 23 fixed to the end thereof and connected by

links

24, 25 to a remote control bar 26. A rod 27 or the like is articulated to lever 23 and is guided for movement in a direction substantially radially of the brake drum 11 by a guide 38 fixed to the brake drum, and, thus, to the tiltable leg structure. When the lever arm 23 is swung into the position which it assumes upon shifting into reverse gear, as shown in FIG. 4, the end portion 37 of the rod 27 projects outwardly alongside of the brake band 12. As best seen in FIG. 3, alongside of lug 14 and preferably forming a part of the lug, there is a laterally projecting post or knob 28, carrying a setscrew 29. The end portion 37 of the rod 27 can cooperate with knob 28 which is fixed to lug 14 through engagement with setscrew 29. When the gear is placed in reverse by raising clutch member 32, which is accomplished by moving control rod 26 to the left as seen in FIG. 2, the rod end 27 is caused to project from the brake drum, as best seen in FIG. 4, and then, when the leg has tilted through a few degrees from normal operating position as a result of the reverse propeller thrust, and when transmission case 5 has rotated therewith slightly in the clockwise direction as seen in FIG. 1, the rod end portion 37 will engage the end of setscrew 29 and move the knob 28 and lug 14 in a direction to tighten the brake band on the drum, thus to arrest the tilting motion of the leg. Setscrew 29 permits adjustment of the number of degrees through which the transmission case will rotate, in the direction of increasing tilt of the leg, in which direction the transmission case tends to rotate when the boat is being driven in reverse, before the brake band tightens on the drum.

While the brake mechanism described above is especially suitable for those boat drives which comprise a tiltable 1. In a boat propulsion arrangement including an outboard power leg tiltably mounted on a boat by means establishing a horizontal tilt axis for said leg, the combination of a brake drum fixed to said leg coaxial with said tilt axis, a friction brake band having opposite ends, a respective lug afiixed to each said end, said band being disposed around said drum with said lugs in proximity, means for urging said lugs toward each other thereby to engage said band with said drum, and for restraining said hand against rotating with said drum, said last means comprising a fixed stop member having a respective stop land for each said lug disposed behind its respective lug and each land being selectively engageable by its respective lug when said leg tends to move on said axis, said last means further comprising a respective spring for each lug, means fixing a first portion of each said spring with respect to said stop member, each said spring having a second portion engaging and urging its respective said lug in a direction toward the other said lug and away from its respective stop land.

2. The combination according to claim 1 wherein the means fixing the first portion of at least one of said springs with respect to said stop member comprises an element adjustably attached to said stop member for adjusting the force exerted by such spring against its respective said lug.

3. The combination according to claim 1 wherein said leg is provided with retractable and extendable forceapplying means disposed, when extended, in a position to impose brake-band-tightening force upon one of said lugs in response to predetermined tilting movement of said leg on said axis and when retracted to be inoperative to impose such force, and wherein means are provided for selectively extending and retracting said force-applying means.

4. The combination according to claim 3 wherein said leg comprises a transmission case at its upper end which is rotatable on said axis, a forward and reverse transmission in said case, a forward-reverse control element entering said case for controlling the transmission, wherein said retractable and extensible force-applying means is positioned upon extension thereof and upon slight tilting of said leg from its operating position, said brake-bandtightening force to that one of said lugs which increases the frictional engagement of said band upon such tilting of the leg, and wherein said extending and retracting means for said force-applying means is coupled to said control element for extending said force applying means in response to operation of said control means in a direction to place said transmission in reverse.

5. The combination according to claim 2 wherein said stop member comprises a post, said lugs being provided with openings through which said post freely extends, wherein said means fixing the first portion of at least said one of said springs comprises a nut, and said post is provided with threads engaged with the threads of said nut.

6. In a boat propulsion arrangement including an outboard power leg tiltably mounted on a boat by means establishing a horizontal tilt axis for said leg, the combination of a brake drum fixed to said leg coaxial with said tilt axis and rotatable in a predetermined direction with tilting of said leg, a friction brake band having opposite ends, a lug affixed to one said end, said band extending from its said one end around said drum in said predetermined direction and having its said ends in proximity, fixed means retaining said other end of said band against movement in a direction opposite to said predetermined direction, and spring means having one portion fixed with respect to said fixed means and another portion engaging said lug urging said 111g toward said opposite direction and toward said other end of the band, whereby said band frictionally retards the return movement of said leg from tilted toward normal operating position. 4

7. The combination according to claim 6 wherein said means retaining said other end of said band includes a stop portion engageable by said other end when said band is frictionally urged by rotation of said drum in said opposite direction and further includes a spring urging said other end in said predetermined direction and away from said stop portion, and wherein fixed stop means are provided in a position to be engaged by and limit the movement of said lug in said predetermined direction against the force of said spring means.

References Cited UNITED STATES PATENTS 1,729,015 9/1929 Seidman. 2,304,646 12/1942 Lear 188-77 X DUANE A. REGER, Primary Examiner.

US. Cl. X.R. 18877, 166

Claims

1. IN A BOAT PROPULSION ARRANGEMENT INCLUDING AN OUTBOARD POWER LEG TILTABLY MOUNTED ON A BOAT BY MEANS ESTABLISHING A HORIZONTAL TILT AXIS FOR SAID LEG, THE COMBINATION OF A BRAKE DRUM FIXED TO SAID LEG COAXIAL WITH SAID TILT AXIS, A FRICTION BRAKE BAND HAVING OPPOSITE ENDS, A RESPECTIVE LUG AFFIXED TO EACH SAID END, SAID BAND BEING DISPOSED AROUND SAID DRUM WITH SAID LUGS IN PROXIMITY, MEANS FOR URGING SAID LUGS TOWARD EACH OTHER THEREBY TO ENGAGE SAID BAND WITH SAID DRUM, AND FOR RESTRAINING SAID BAND AGAINST ROTATING WITH SAID DRUM, SAID LAST MEANS COMPRISING A FIXED STOP MEMBER HAVING A RESPECTIVE STOP LAND FOR EACH SAID LUG DISPOSED BEHIND ITS RESPECTIVE LUG AND EACH LAND BEING SELECTIVELY ENGAGEABLE BY ITS RESPECTIVE LUG WHEN SAID LEG TENDS TO MOVE ON SAID AXIS, SAID LAST MEANS FURTHER COMPRISING A RESPECTIVE SPRING FOR EACH LUG, MEANS FIXING A FIRST PORTION OF EACH SAID SPRING WITH RESPECT TO SAID STOP MEMBER, EACH SAID SPRING HAVING A SECOND PORTION ENGAGING AND URGING ITS RESPECTIVE SAID LUG IN A DIRECTION TOWARD THE OTHER SAID LUG AND AWAY FROM ITS RESPECTIVE STOP LAND.