US3796178A

US3796178A - Boat steering and reversing system

Info

Publication number: US3796178A
Application number: US00284179A
Authority: US
Inventors: J Smith
Original assignee: Wolverine Pentronix Inc
Current assignee: Wolverine Pentronix Inc
Priority date: 1972-08-28
Filing date: 1972-08-28
Publication date: 1974-03-12
Anticipated expiration: 1991-03-12

Abstract

A system for controlling the forward and reverse operation of a boat having a propulsion unit mounted on the boat and rotatable to provide normal steering of the boat. Included is a mechanism for initiating a rapid rotating of the propulsion unit through a turn of approximately one-half circle to redirect the force of propulsion forwardly and thus provide reverse drive of the boat. The mechanism comprises a rotating gear associated with the propulsion unit itself for generating and applying a turning moment of force or torque for reorienting the propulsion unit through the half-circle turn. A detent means is coupled to the unit and selectively positioned by a manual control lever in the path of a stop mounted on the unit during its turning to retain it in either the forward or the reverse drive position.

Description

[ Mar. 12, 1974 BOAT STEERING AND REVERSING SYSTEM Inventor: Joseph E. Smith, Birmingham,

Mich.

3,738,306 6/1973 Pinkerton ll5/35 Primary Examiner-Duanc A. Regcr Assistant ExaminerCharles E. Frankfort Attorney, Agent, or FirmHauke, Gifford, Potalidis &

I73] Assignee: Wolverine-Pentronix, lnc., Lincoln Dumont Park, Mich. 1221 Filed: Aug. 28, 1972 ABSTRALT A system for controlling the forward and reverse oper- [211 Appl' N05 284,179 ation of a boat having a propulsion unit mounted on Related Application Dam the boat and rotatable to provide normal steering of [631 Continuatiomim an of Scr NO 249 '68 Ma 1 the boat. Included is a mechanism for initiating a rapid 1972 p y rotating of the propulsion unit through a turn of approximately one-half circle to redirect the force of 52 US. Cl. 114/144 R 115/35 Propulsimforwardly and thus Pmide reverse drive of 51 Int. Cl B6311 25/42 the boat- The mechanism mPrises rotating gear [58] Field of Search 115/34 35 17 18- associated with the P P "self for 114/144 154 155 ing and applying a turning moment of force or torque for reorienting the propulsion unit through the half- [56] References Cited circle turn. A detent means is coupled to the unit and selectively positioned by a manual control lever in the UNITED STATES PATENTS path of astop mounted on the unit during its turning g l t lto retain it in either the forward or the reverse drive rcxere a.... 1,903,265 3 1933 Peck 115 35 l" 3,486,478 12/1969 Halliday ll5/35 21 Claims, 7 Drawing Figures 3z- 2g 46 I l -56 ZZ\ 40 I] 2 1 ll l l 1 27 l M 10- i /Z 1.3 .3 j ::j 1]) PATENTEMAR 12 I974 SHEE! 3 OF 3 Fig -2 PATENTEDHAR 1 2 mm 3796 1'78

sum

3 or 3 BOAT STEERING AND REVERSING SYSTEM REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of U.S. application Ser. No. 249,168 filed May 1, 1972 for Boat Steering and Reversing Mechanism.

BACKGROUND OF THE INVENTION This invention relates to a steering and reversing system for boats or other watercraft in which there is provided a propulsion unit adapted to provide .a variable magnitude thrust force generally rearwardly of the boat to move it in a forward direction. The invention is particularly suitable for use with a propulsion system in which the propulsion unit is rotated about a substantially vertical axis to provide for controllable steering of the boat. The major directional control is through the selective directing of the thrust force through the propulsion unit itself, which may incorporate a modified rudder construction when rudder effect is desired.

The present invention may be applied to propulsion systems comprising dual units and in which internal combustion engines are included for driving the propellers and thus generating the thrust force. Alternately, the propulsion unit may be connected to a hydraulic motor, an electrical motor, a turbine engine, a Wankeltype engine, or any other convenient prime mover. The changeover between forward and reverse operation of the boat is achieved by means of a rapid reversing mechanism which utilizes the reaction torque generated by a rotating element of the propulsion unit to reorient the thrust vector direction.

Prior art propulsion systems for watercraft disclose a variety of drive systems in which there is generally included a propulsion unit, consisting of the propeller shaft housingand propeller, sometimes with a modified rudder or fin, which is manually rotatable for steering of the boat. An example of this type of mechanism is shown and described in U.S. Pat. No. 1,693,590. U.S. Pat. No. 1,866,482 discloses a similar arrangement, but in which the motor unit is fixed to the boat hull and steering is achieved by rotating the propulsion unit through a cable and bevel gear arrangement.

U.S. Pat. No. 1,824,213 is another example of a disclosure of an outboard motor wherein the propeller housing is rotatably controlled relative to the motor housing for steering of the boat. Rotating action is provided in that case by the direct mechanical forces applied by a sector gear and rack mechanism.

Other mechanisms are known, similar to that dis closed in U.S. Pat. No. 1,774,956, in which the propulsion unit and steering unit include a turret-like structure which encloses the driveshaft and the lowermost projecting portion of the propulsion unit. For normal steering, the turret-like structure is turned about a substantially vertical axis through a gear coupled to the steering wheel and in mesh with a ring gear mounted on the turret-like structure.

It is also known to rotate a propulsion unit through a turn of essentially 180 in order to reverse the direction of the thrust force and hence the direction in which the boat is driven. The mechanisms to provide this rotating effect are for the most part directly operable through the steering wheel and the extent of turning is not precisely controllable by the operator. Additionally, relatively large magnitude forces must be applied from an external source to provide the rapid changeover between the forward and reverse direction.

All of the aforesaid arrangements are subject to the obvious disadvantages arising from the face that the rotatable propulsion unit itself is not visible to the operator and the steering wheel does not always clearly indicate the exact angular position of the propulsion unit relative to the hull axis.

Other patents and publications have shown steering systems which make general reference to the rapid turning of the propulsion unit through a turn approximating-. But while these in several cases, for example in U.S. Pat. No. 2,834,313, refer to providing a quick rotation, there is no actual disclosure of a working mechanism whereby such turning may be achieved.

The present invention provides a mechanism which I utilizes the resultant torque or reaction force generated as a result of applying a drive torque to the various rotating elements of the propulsion unit to rapidly rotate the propulsion unit 180 from its original orientation to reverse the direction of travel of the boat.

SUMMARY OF THE PRESENT INVENTION The present invention thus relates to a rapid reversal mechanism for reorienting a watercraft propulsion unit in which the reversing mechanism is operable by forces independent of the normal steering system and without the need of a complicated reverse drive or gear train mechanism. The present invention in its simplest form includes a reverse control system in which a manually operated detent-stop mechanism provides limits for rotation of the propulsion unit through a 180 turn between two arcuately spaced positions, one representing the forward and the other' representing the reverse orientation of the thrust force. The mechanism itself in one embodiment is constructed to include an offset propeller to provide the torque to rotate the propulsion unit in which the propeller is mounted. Alternately, the torque for rapidly rotating the propulsion unit may be derived from the reaction forces applied upon the propulsion unit housing and caused by drive torque applied to the propeller shaft. In this manner, the reversing control system needs only a manually operated means to arrest the rotating of the propulsion unit in the position desired, while the turning force is rapidly generated through the unit itself. The manually operated means includes a rockable lever which is operated through a reversing control lever and cable arrangement.

BRIEF DESCRIPTION OF'THE DRAWINGS The present invention will be described in the accompanying specification with reference to the accompanying drawings in which like numerals are used to refer to like parts which appear in the several views, and wherein:

FIG. 1 is a partly schematic, cross-sectional view of a propeller type propulsion unit, with parts broken away;

FIG. 2 is a partly schematic, cross-sectional view of an alternate embodiment of the present invention, with parts broken away;

FIG. 3 is a sectional view taken along the line 3 3 of FIG. 2;

FIG. 4 is a partly schematic, cross-sectional view of a further embodiment of the present invention, with parts broken away;

shown in FIGS. 2 and 3.

DETAILED DESCRIPTION 7 With reference to FIG. I, the drawing illustrates the basic parts of a boat propulsion unit I5 which is of the propeller driven type. The propulsion unit is adapted for mounting on a boat transom, as will be shown in FIGS. 6 and 7 hereinafter, although the control system of the invention may also be used in conjunction with propulsion units of the inboard/outboard type as well as those mounted amidship or forward on the boat in a tunnel or in a well. Included in the unit is a driveshaft 10 which is vertically disposed and provided with a bevel gear 12 keyed to its lower end. A drive source, such as the output shaft of an internal combustion engine, not shown, is coupled to the upper end of the driveshaft 10. The driveshaft 10 is enclosed within a steering tube 14. The steering tube 14 is connectible at an intermediate portion to the propulsion unit 15 through

detents

40 or 42 The steering tube 14 and the propulsion unit 15 are both rotatable by means of a steering control wheel and associated linkage to provide normal steering. Reference is made to the aforementioned U.S. Pat. application Ser. No. 249,146 for an explanation of an appropriate steering system to be employed at the upper end of the steering tube 14. The lower portion of the propulsion unit 15 consists of a housing 16 enclosing a propeller shaft 17 journalled for rotation between a pair of spaced bearings 18. The right-hand end, as shown in the drawing, of the propeller shaft 17 projects from the housing 16, and has a propeller 19 mounted thereon. A bevel gear 20 is keyed to the propellershaft l7 proximate its left-hand end and is in mesh with the bevel gear 12 mounted at the lower end of the driveshaft 10 to be driven therefrom. The propulsion unit 15 is rotatable about a substantially vertical axis as a result of being mounted for free rotation relative to a supporting strut 22, which in turn is fixedly mounted on the boat. The lower portion of the supporting strut 22 is provided with a recessed annular bearing surface 24 accepting a radially extending flange 26 affixed to, or formed integral with, the top portion of the propulsion unit housing 16. A segmented retainer ring 27, affixed to the end of the supporting strut 22 by any convenient means such as bolts, not shown, maintains the flange 26 within the annular recess in the end of the strut 22, and thrust and other bearing members, not shown, may be disposed between the engaged surfaces to reduce friction. Unless otherwise restrained, the propulsion unit housing 16 is thus free to rotate about a vertical axis relative to the support strut 22 and also relative to the steering tube 14.

As also shown in FIG. 1, a manual control is provided for effecting changeover of drive between forward and reverse modes. The manual control includes a reversing lever 28 which is pivotably mounted about a horizontal axis on a pivot pin 30 affixed to the steering tube 14. The lever 28 further includes an upstanding arm 32 to the end of which is attached a reverse cable 34. A pair of lateral arms 36 and 38 are each pivotably mounted at an end detent of the lever 28 and are provided with a detent mechanism, 40 and 42, respectively. It will be seen that each of the

detent mechanisms

40, 42 is freely pivotably mounted on its respective arm 36, 38 so that according to the rocking movement of the lever 28 about the pin 30, one or the other of the

detent mechanisms

40, 42 is placed in the path ofa fixed stop 44, which stop is fixed to the upper surface of the flange portion 26 of the propulsion unit housing I6.

A manually operated lever 46 is schematically represented with the three positions forward," neutral and reverse indicated by letter designation F, N and R, respectively. The propulsion unit 15 is illustrated at FIG. 1 in its forward position in which the detent mechanism 40 is in abutment with the stop 44 to prevent rotating of the propulsion unit housing 16 relative to the steering tube 14 and thus direct the thrust force from the propeller 19 in a generally rearward direction, while permitting controlled steering of the boat by rotating the steering tube 14 about a vertical axis by means of the normal steering mechanism. When the lever 46 is placed in its right-hand or reverse position, as designated by the letter R, the lever 28 will be rocked in a clockwise direction to place the detent mechanism 42 in the path of the stop 44, thus finally arresting the rotation of the propulsion unit 15 at a point substantially from its original or forward position. With the propeller 19 turning, the drive gear 12 mounted on the lower end of the driveshaft 10 will provide a torque force T to make a rotation of the propulsion unit 15 into its reverse operating position. The force T is directed, as indicated by arrow, to rotate the propulsion unit 15 in a counterclockwise direction about the axis of the driveshaft 10.

Also shown in the FIG. 1 drawing in block diagram form is a clutch 48 which is operable in the intermediate or neutral position of the control lever 46 to provide for disengagement of the drive from the engine associated with the driveshaft 10. The clutch 48 may either be a mechanically operated dog-type clutch, a solenoid operated clutch, a hydraulic operated clutch, or the like. Examples of several clutch mechanisms suitable for use in connection with the present invention are shown and described in US. Pat. application Ser. No. 249,168 hereinbefore referred to.

FIGS. 2 and 3 show an alternate embodiment of the present invention in which the basic parts of the propulsion unit 15, including the driveshaft'lO, the bevel gear 12, the steering tube 14 and the propulsion unit housing 16, are mounted on a boat rear transom, with the rotation and changeover between forward and reverse operation provided by the turning of the propulsion unit 15 through a differently generated torque. The turning force applied to the propulsion unit 15 is provided by an arrangement whereby the propeller 19 is offset from the axis of the driveshaft l0. Included in the mechanism is a separate propeller shaft 49 which is journalled at its right-hand end for rotation in a bearing 50. The shaft 49 is also journalled for rotation at its left-hand end in a suitable bearing and support plate 52. The propeller shaft 17, which carries the bevel gear 20, is likewise journalled for rotation in the plate 52. Drive is transmitted from shaft 17 to shaft 49 through a gear set including a pinion gear 54 fixed to the righthand end of the shaft 17 and a pinion gear 56 fixed to the left-hand end of the shaft 49 and in mesh with the gear 54.

Reversing control is provided through a rockable lever 58, which is pivotably mounted as-shown, alternately and selectively positions the

detent mechanism

40 or 42 into or away from alignment with the stop 44 extending from the upper surface of the propulsion unit 15. In a manner similar to the FIG. 1 embodiment, there is included a clutch 48 which is actuated in the neutral position by the control lever 46 to disconnect engine drive from the driveshaft 10. The detail of construction of the clutch 48 is omitted in the interest of brevity.

FIG. 4 shows a different embodiment of the present invention which is substantially similar to the embodiment of FIG. 1 except that the clutch 48 is located proximate the lower end of the driveshaft on which the gear 12 is fixed. The clutch 48 is positioned in an opening 58 formed centrally in the propulsion unit 15. The entire propulsion unit 15 is rotated counterclockwise about the axis of the steering tube 14, while the operation of the reversing control lever 28 raises detent mechanism 40 and lowers detent mechanism 42 into the path of the upwardly extending stop 44. This stops and retains the propulsion unit 15 in its forward or reverse operating position. In a similar manner to the embodiment of FIG. 1, the clutch 48 is operable in the neutral selection position of the lever 46 to disconnect drive from driveshaft 10 and hence from the propulsion unit 15. It will be understood that the supporting struts 22 are attached to a suitable mounting bracket fixed to the boat transom.

While the present invention is generally illustrated and described with respect to the propulsion unit 15 being mounted at the rear end of the boat, the invention is not so limited, but is equally adaptable for forward or amidship installation on a boat. The clutch 48 may be of the conventional type, either electrically or mechanically actuated, and used with a split-type driveshaft 10.

The FIG. 5 embodiment is substantially similar to the one disclosed in the aforementioned US. Pat. application Ser. No. 249,l68 in FIG. 4 thereof. The propulsion unit 15, which is connected at its upper end to the steering tube 14, provides for rotating action and normal steering of the boat. The control mechanism includes, in addition to the vertical driveshaft 10, a neutral tube 60 which at its upper end is suitably actuated through movement of the reversing cable 34. According to the operation of the neutral tube 60, a separate clutch 62, which is slidably mounted relative to the propeller driveshaft 17 at its left-hand end, is used-to selec tively engage and disengage the lower gear from driving relationship with the propeller driveshaft 17. The neutral control tube 60 has a sector gear 64 fixed to its lower end and in mesh with a pinion gear 66 fixed to the upper end ofa rod 68. The rod 68 carries a lower cam disk 70 which is engageable with the forward end of a clutch pin 72. It will be understood that the gear 20 is a free-running gear rotatably mounted with respect to the propeller driveshaft 17. When the neutral tube 60 and the sector gear 64 rotate, the neutral pinion gear 66 will then turn the cam 70 and cause it to provide a depression of the clutch pin 72. The operation of the clutch pin 72 will move the clutch 62 and disengage it from the gear 20. The bevel gear 20 thus is permitted to spin freely on the propeller driveshaft 17, while the propeller 19 is not being rotated. A torque T in the direction indicated by the arrow, is generated by the resistance which the gear 20 offers to the bevel drive gear 12. This torque will rotate the entire propulsion unit 15 once the reverse cable has been operated. The selection of forward or reverse operation is made by the actuation of the reversing control lever 46 which serves to rock the lever 28 either clockwise or counterclockwise to place the detent mechanism 40 or the detent mechanism 42 in limiting abutment with the stop 44.

FIG. 6 illustrates the manner in which a dual installation including two propeller type propulsion units 15 are mounted on the transom 72 of a boat 74. Each of the two propulsion units 15 are mounted on a suitable bracket 76 with the units rotatable about their respective vertically oriented driveshaft 10 in accordance with the operational explanation given in connectionwith FIG. I. The turning force for each unit 15 is derived from the rotation of its associated bevel gear 12. In order to neutralize side thrust forces, the propeller driveshaft l0 and the associated right-hand propulsion unit 15 are rotated in a counterclockwise direction, while the driveshaft 10 and the associated left-hand propulsion unit 15 are oppositely rotated in a clockwise direction. Thus, the turning moment applied to the right-hand unit is counterclockwise, while the turning moment applied to the left-hand unit is clockwise, and the arcuate paths followed by the two units during reversal changeover are in opposing directions as indicated by the arrows.

FIG. 7 shows a dual installation on a boat 74 of a pair of propulsion units 15, each of which is constructed like the embodiment of FIG. 2, with the propulsion unit housing 16 and propeller in each case offset relative to the substantially vertical axis of the driveshaft 10. In this manner there is provided an opposite direction turning moment about each of the axes of rotation as indicated by the arrows. Here again the advantage of the dual installation and of the particular embodiment of the unit used is that the side thrust forces are neutralized and the stability of the boat during direction changeover is greatly improved.

It will thus be seen that by the present invention in its several embodiments there is provided a novel and improved boat propulsion system with a simplified mechanism for providing changeover between forward and reverse operation. The system requires no external force in its operation. A force of turning for the propulsion unit is generated by the unique arrangement of elements associated with or within the unit itself.

What is claimed is:

11. In a boat having a propulsion unit mounted on it and rotatable about a substantially vertical axis, a drive means for providing a rotative drive to said unit, a steering means, a means connected between said steering means and said propulsion unit for normally steering it in a forward direction, and a control system operatively connected to and controlling said propulsion unit for rapidly turning it about said axis through a turn of substantially to effect a changeover between forward and reverse drive of the boat, said system including a stop mounted on said propulsion unit and a pair of oppositely disposed detents, each selectively engageable with said stop to retain said unit in a forward or in a rearward drive position, said unit operable to rotate itself between said forward and reverse drive positions responsive to the torque provided by said drive means.

2. The combination as set forth in claim 1 wherein said detents are both suspended from a common operating lever, said lever shiftable by a reversing cable coupled thereto.

3. The combination as set forth in claim ll wherein said drive means comprises an engine driveshaft connected to said propulsion unit for driving it, said propulsion unit further including a propeller and a propeller driveshaft mounted between said engine driveshaft and said propeller.

4. The combination as set forth in claim 3 wherein a pair of said propulsion units are mounted in spaced relationship on said boat, said propellers normally rotatable by said engine driveshafts in opposite directions to null side thrust forces during changeover between forward and reverse positions.

5. In a boat having a propulsion unit mounted on it and rotatable about a substantially vertical axis, a steering means, a connecting means coupled between said steering means and said propulsion unit for normally steering it in a forward direction, and a control system operatively connected to and controlling said propulsion unit for rapidly rotating it about said axis through a turn of substantially 180 to effect a changeover be tween forward and reverse drive for the boat, said system including a substantially vertical driveshaft having a gear mounted thereon, a propeller, a propeller driveshaft having said propeller fixed proximate one end and a gear fixed proximate the other end, said gears in mesh, a stop fixed to a substantially horizontal surface of said unit, a pair of detents spaced approximately 180 apart and selectively engageable with said stop to retain said unit in position after changeover between forward and reverse drive, said gear on said driveshaft operable to provide a torque force for rotating the pro pulsion unit during said changeover.

6. The combination as set forth in claim 5 wherein said detents are mounted at opposite ends of a lever, and a reversing cable is coupled to said lever for operating it.

7. The combination as set forth in claim 5 wherein an engine driveshaft is connected to said propulsion unit for driving it and wherein a clutch means is operably connected to said driveshaft for providing drive disconnect from said propeller driveshaft.

8. The combination as set forth in claim 5 wherein a pair of said propulsion units are mounted and laterally spaced one from the other on said boat, each of said propulsion units having its propeller normally rotated in a different direction to minimize side thrust during the changeover between forward and reverse drive of the boat.

9. The combination as set forth in claim 6 wherein said lever is pivotally mounted at a point proximate with the axis of said vertical driveshaft, said lever having an upstanding arm coupled to said reversing cable.

10. In a boat having a propulsion unit mounted on it and rotatable about an upstanding axis, a steering means, a connecting means coupled between said steering means and said propulsion unit for normally steering it in a forward direction, and a control system operatively connected to and controlling said propulsion unit for rapidly rotating it about said axis through a half-circle turn to effect a changeover between forward and reverse drive for the boat, said system including a substantially vertical engine driveshaft having a gear mounted thereon, a propeller, a propeller driveshaft having said propeller fixed to one end and a gear fixed proximate the other end and in driven relationship with said first mentioned gear, said propeller drive shaft including a connecting means for offsetting said propeller and said propeller driveshaft relative to said axis, a stop fixed to said unit, a pair of detents arcuately spaced apart and singly engageable with said stop to retain said unit in position after changeover between forward and reverse drive, said propeller operable to provide a torque force to said unit during propeller rotation.

H. The combination as set forth in claim 10 wherein said detents are mounted on a lever, said lever pivotally mounted and having one end coupled to a reversing cable for positioning a selected one of said detents in the path of said stop.

12. The combination as set forth in claim 10 wherein said engine driveshaft has a clutch means operatively connected thereto for disconnecting its drive from said propeller shaft during said changeover.

13. The combination as set forth in claim 10 wherein said stop is mounted on an upper planar surface of said unit, said unit further including a lateral bearing extension supporting it for rotation about said axis.

14. The combination as set forth in claim 10 wherein said detents are each mounted on a different downwardly extending lever arm, said arms pivotally attached to a rockable lever for raising one of said detents and lowering the other of said detents into operable relationship with said stop.

15. The combination as set forth in claim 10 wherein a pair of such propulsion units, each having a propeller, are mounted in spaced relationship upon said boat, both of said propellers being angularly offset in opposite directions relative to their respective vertical axis to provide for their rotation between forward and reverse positions in opposite directions to null side thrust forces during said changeover.

16. In a boat having a propulsion unit mounted on it and rotatable about a substantially vertical axis, a steering means, a steering cable connected between said steering means and said propulsion unit for normally steering it in a forward direction, a control system operatively connected to and controlling said propulsion unit for rapidly turning it about said axis through substantially a half-circle turn to effect a changeover between a forward and a reverse drive orientation relative to the boat, said system including a substantially vertical engine driveshaft connectable to an engine for receiving a rotatable drive therefrom, said driveshaft aligned with said axis, a first gear fixed to said driveshaft, a propeller and a propeller driveshaft rotatably mounted in said unit, a second free-running gear associated with said propeller driveshaft and in continuous driven mesh with said first gear, and a clutch means operably connected to said driveshaft for selectively disconnecting said second gear from said propeller driveshaft and interrupting drive to said propeller, a projection extending from the surface of said propulsion unit and a pair of detents selectively engageable one at a time with said projection to arrest the movement of said unit in one of said orientations.

17. The combination as set forth in claim 16 wherein said detents comprise a pair of detents rockably mounted and movable into and away from opposed relationship to said projection on said propulsion unit.

18. The combination as set forth in claim 17 wherein a reversing cable is operably connected to said detents to operate one of same into' the path of said projection on said propulsion unit.

19 In a boat having a propulsion unit mounted on it and rotatable about a substantially vertical axis, a steering means, a connecting means between said steering means and said propulsion unit for normally steering it in a forward direction, and a control means operably connected to and controlling said propulsion unit for rapidly turning it about said axis through a turn of substantially 180 to effect a changeover between forward and reverse drive of the boat, said control system ineluding a stop means fixed on the upper surface of said propulsion unit, a pair-of spaced detents for arresting its rotation in a forward and a reverse drive position, respectively, and a rotating means for providing a torque to said unit during changeover turning of said propulsion unit.

20. The combination as set forth in claim 19 wherein said last mentioned means comprises a vertically oriented driveshaft aligned with said axis and a gear fixed to said shaft.

2l. The combination as set forth in claim I) wherein said last mentioned means comprises a propeller mounted on said unit and offset relative to said vertical axis.

Claims

1. In a boat having a propulsion unit mounted on it and rotatable about a substantially vertical axis, a drive means for providing a rotative drive to said unit, a steering means, a means connected between said steering means and said propulsion unit for normally steering it in a forward direction, and a control system operatively connected to and controlling said propulsion unit for rapidly turning it about said axis through a turn of substantially 180* to effect a changeover between forward and reverse drive of the boat, said system including a stop mounted on said propulsion unit and a pair of oppositely disposed detents, each selectively engageable with said stop to retain said unit in a forward or in a rearward drive position, said unit operable to rotate itself between said forward and reverse drive positions responsive to the torque provided by said drive means.

3. The combination as set forth in claim 1 wherein said drive means comprises an engine driveshaft connected to said propulsion unit for driving it, said propulsion unit further including a propeller and a propeller driveshaft mounted between said engine driveshaft and said propeller.

5. In a boat having a propulsion unit mounted on it and rotatable about a substantially vertical axis, a steering means, a connecting means coupled between said steering means and said propulsion unit for normally steering it in a forward direction, and a control system operatively connected to and controlling said propulsion unit for rapidly rotating it about said axis through a turn of substantially 180* to effect a changeover between forward and reverse drive for the boat, said system including a substantially vertical driveshaft having a gear mounted thereon, a propeller, a propeller driveshaft having said propeller fixed proximate one end and a gear fixed proximate the other end, said gears in mesh, a stop fixed to a substantially horizontal surface of said unit, a pair of detents spaced approximately 180* apart and selectively engageable with said stop to retain said unit in position after changeover between forward and reverse drive, said gear on said driveshaft operablE to provide a torque force for rotating the propulsion unit during said changeover.

10. In a boat having a propulsion unit mounted on it and rotatable about an upstanding axis, a steering means, a connecting means coupled between said steering means and said propulsion unit for normally steering it in a forward direction, and a control system operatively connected to and controlling said propulsion unit for rapidly rotating it about said axis through a half-circle turn to effect a changeover between forward and reverse drive for the boat, said system including a substantially vertical engine driveshaft having a gear mounted thereon, a propeller, a propeller driveshaft having said propeller fixed to one end and a gear fixed proximate the other end and in driven relationship with said first mentioned gear, said propeller driveshaft including a connecting means for offsetting said propeller and said propeller driveshaft relative to said axis, a stop fixed to said unit, a pair of detents arcuately spaced 180* apart and singly engageable with said stop to retain said unit in position after changeover between forward and reverse drive, said propeller operable to provide a torque force to said unit during propeller rotation.

11. The combination as set forth in claim 10 wherein said detents are mounted on a lever, said lever pivotally mounted and having one end coupled to a reversing cable for positioning a selected one of said detents in the path of said stop.

18. The combination as set forth in claim 17 wherein a reversing cable is operably connected to said detents to operate one of same into the path of said projection on said propulsion unit.

19. In a boat having a propulsion unit mounted on it and rotatable about a substantially vertical axis, a steering means, a connecting means between said steering means and said propulsion unit for normally steering it in a forward direction, and a control means operably connected to and controlling said propulsion unit for rapidly turning it about said axis through a turn of substantially 180* to effect a changeover between forward and reverse drive of the boat, said control system including a stop means fixed on the upper surface of said propulsion unit, a pair of spaced detents for arresting its rotation in a forward and a reverse drive position, respectively, and a rotating means for providing a torque to said unit during changeover turning of said propulsion unit.

21. The combination as set forth in claim 19 wherein said last mentioned means comprises a propeller mounted on said unit and offset relative to said vertical axis.