US3651779A

US3651779A - Electrical steering system for boats

Info

Publication number: US3651779A
Application number: US25874A
Authority: US
Inventors: Calhoun Norton
Original assignee: ARENS CONTROLS Inc
Current assignee: ARENS CONTROLS Inc
Priority date: 1970-04-06
Filing date: 1970-04-06
Publication date: 1972-03-28
Anticipated expiration: 1989-03-28

Abstract

There is disclosed a control system for electronically controlling a boat powered by a conventional twin screw inboard-outboard drive system. The boat is maneuvered by a plurality of reversible direct current motors which are controlled through a complex electronic circuit system by a portable control box. The portable control box is disengageably connected to the electronic system so that the boat may be maneuvered from any position thereon.

Description

llite States Patent Norton [4 a1". 2%, 1972 [s41 ELEETRICAIL STEERING SYSTEM FOR 2,498,223 2/1950 Rommel ..114/144 BQATS 3,013,519 12/1961 Wiggermann 3,187,704 6/1965 Shatto, Jr. et al..... I 1 Inventor Calhoun Nam, mm 3,481,299 12/1969 Horn ..114/144 3 "l ['7 A1 gnee Aron Controls, lac Evanston 111 Primary Examiw Mflmn Buckle: [22] Flled: Apr- 6, 1 Assistant Examiner-CarlA. Rutledge [211 App! No 25 874 Attorney-Olson, Trexler, Wolters & Bushnell [57] ABSTRACT 'i l There is disclosed a control system for electronically con- [58] Fieid 8 E 34 trolling a boat powered by a conventional twin screw inboard- -outboa.rd drive system. The boat is maneuvered by a plurality of reversible direct current motors which are controlled through a complex electronic circuit system by a portable con- [56] References Cited trol box. The portable control box is disengageably connected UNITED STATES PATENTS to the electronic system so that the boat may be maneuvered from any position thereon. 2,804,838 9/1957 Moser ..115/18 2,877,733 3/1959 Harris ..115/18 7 Claims, 6 Drawing Figures This invention relates generally to a control system for maneuvering a boat, and more particularly to an electronic control system for maneuvering a boat.

In the past, steering arrangements for boats were disclosed in accordance with my own U.S. Pat. No. 3,294,054 which shows a mechanically coupled steering system without the use of electronic controls. Although the system therein disclosed provides an excellent steering mechanism for facilitating maneuvering of the boat, it has been found that by utilizing an electronic control system, as disclosed hereinafter, the ability to maneuver a boat is enhanced. It has also been found that boat maneuverability can be controlled from any position on the boat whereas such a feat is not possible to utilizing a mechanically coupled system by itself.

Accordingly, a general object of the present invention is to provide a novel electronic control system for maneuvering a boat.

Another object of the present invention is to provide an electronic control system for maneuvering a boat wherein maneuvering can be accomplished from any desired position.

A more specific object of the present invention is to provide an electronic control system for controlling the maneuverability of a boat wherein the clutch, throttle, and steering mechanism of the drive system can be independently regulating from various remote positions.

A further object of the present invention is to provide novel electronic control circuits for the control of the clutch, throttle and steering mechanisms of a boat drive system.

Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a block diagram of the electronic control system for controlling the maneuverability of a boat powered by a twin screw inboard--outboard drive system;

FIG. 2 is a block diagram of the electronic control circuit for controlling the throttles and steering of the boat;

FIG. 3 is a schematic diagram of the electronic control circuit for controlling the steering of the boat;

FIG. 4 is a schematic diagram of the direct current reversible motors used in conjunction with the electronic control circuit of FIG. 3 for controlling the steering of the boat;

FIG. 5 is a schematic diagram of the electronic control circuit and direct current reversible motor for controlling the throttles of the boat; and,

FIG. 6 is a schematic diagram of the electronic control circuit and direct current reversible motor for controlling the clutch mechanisms of the boat.

Referring now more specifically to the drawings and particularly to FIG. 1, the rear end section of a boat 10 is shown, conventionally powered by a twin screw inboard--outboard drive system designated generally by the

numerals

12 and 14 although it is to be understood that conventional outboard engines could also be used. An electronic control system designated generally by the numeral 16 electronically controls the maneuverability of the boat 10 in the same manner as the boat disclosed in my patent, U.S. Pat. No. 3,294,054, is maneuvered but with a higher degree of accuracy. For a discussion of the particular maneuvering positions and the various forces required for these respective positions, reference is made to the above mentioned patent.

The inboard--outboard drive system 12 is positioned on the left or port side of the boat and includes an engine 18 mounted within the boat providing the power for a port outboard drive unit 20 conventionally mounted on the boat transom at the rear or stem of the boat. A movable throttle arm 21 cooperates with the engine 18 for varying the power output of the engine from no power or idle power when the throttle arm is in the position as indicated in solid lines to full power when the throttle arm is positioned as indicated in dotted lines.

boat transom. A tiller or steering lever 24 is provided for swinging the drive unit to the left or right about a generally vertical pivot 26, as viewed in FIG. 1, to change the angle of The outboard drive unit 20 includes a propeller 22 mounted v on the end of a propeller shaft (not shown) which extends in a generally horizontal position rearwardly with respect to the thrust of the propeller with respect to a longitudinal axis 23 of the boat. The extreme positions, both left and right, of the outboard drive unit 20 are indicated by dotted lines in FIG. ll. An engageable clutch member 30 is provided for engaging and disengaging the engine 18 and outboard drive unit 20. As indicated in FIG. 1, the clutch can be positioned to the far left for engaging the engine and outboard drive unit wherein the propeller 22 is driven in one direction for providing forward power to the boat 10. The propeller is driven in an opposite direction for providing rearward power to the boat 10 by positioning the clutch member 30 to the far right and finally, positioning the clutch intermediate the two above described extreme positions disengages the motor and drive unit.

The inboard--outboard drive system 14 is positioned on the right or starboard side of the boat and includes an engine ma mounted within the boat providing the power for a starboard outboard drive unit 20a mounted on the boat transom at the rear or stem of the boat. The inboard--outboard drive system 14 is structurally or functionally exactly the same as the inboard--outboard drive system 12 and therefore like components are designated with like numbers with an additional suffix a indicating the components of the drive system 14.

The maneuverability of the boat 10 is dependent upon three factors, firstly, the physical positioning of the

propellers

22 and 22a with respect to the longitudinal axis 28 of the boat, secondly, the amount of power delivered by the

engines

18 and 18a which is determined by the positions of throttle arms 21 and 21a, and thirdly, by the

direction propellers

22 and 22a are driven which is dependent upon whether the

clutches

30 and 30a engage their respective engine and drive unit in a forward or reverse manner. As stated above, reference can be made to my patent, U.S. Pat. No. 3,294,054, for a detailed description of the various maneuvering positions utilizing these factors.

For each inboard--

outboard drive system

12 and 14, the electronic control system 16 provides a

steering motor assembly

32 and 32a respectively, a

throttle motor assembly

34 and 34a respectively, and a clutch motor assembly 36 and 360 respectively. The steering motor assemblies 32 and 32a control the positioning of their

respective drive units

20 and 20a as described in more detail hereinafter. The

throttle motor assemblies

34 and 34a are used to position their respective throttle arms 21 and 21a for controlling the power output of their

respective engines

18 and 18a and the

clutch motor assemblies

36 and 36a are provided for positioning their

respective clutch members

30 and 30a for controlling the engaging status of their respective engine and outboard drive units.

The electronic control 16 also includes electronic control circuitry, described in detail hereinafter, positioned within a control panel 38 which may be mounted on boat 10 in any convenient location. The control circuitry is electrically connected to the above described motor assemblies via conduits 40 for controlling the motor assemblies as described below. Additional electronic control circuitry co-operating with the circuitry within control panel 38 is located within a portable control box 42. The control circuitry within the control box may be disengageably connected to the control circuitry within control panel 38 for co-operating therewith. This is accomplished by an electrical cord and plug 44 which cooperates with a socket 46 for connecting and disconnecting the electronic circuitry in control panel 38 and portable control box 42. This disengageable feature allows the operator of boat 10 to maneuver the boat from any position thereon merely by supplying an appropriate extension cord (not shown) or if desired by providing additional sockets located in various positions on the boat and connecting the electronic circuitry within control panel 38 to those sockets.

The steering motor assembly 32 includes a reversible direct current motor 48 and a piston assembly 50 mechanically coupled to the output of reversible motor 48 for driving a piston or actuator 52 of the piston assembly 50. The piston 52 is driven from a retracted position as indicated by solid lines in FIG. 1 to an extended position as indicated in dotted lines when the reversible motor 48 is forwardly driven and back to its retracted position when the reversible motor is reversely driven. It is to be understood that the reversible direct current motor and the piston assembly are both conventional and conventionally coupled to each other so as to provide the above described results and therefore will not be discussed in further detail. The free end of piston 52 which may be a gear driven rack is mechanically connected to the steering lever 24 of the port outboard drive unit 20 by means not shown so as to drive the outboard drive unit and corresponding propeller 22 from the extreme right as viewed in Fig. 1 when the piston is in its extended position to the extreme left when the piston is in its retracted position.

A steering motor assembly 32a which is both structurally and functionally identical to the steering motor assembly 32 is mechanically coupled to the steering lever 24a of the starboard outboard drive unit 20a in the same manner as steering motor assembly 32 is coupled to steering lever 24. The reversible direct current motor, piston assembly, and actuator of the steering motor assembly 32a are designated by numerals 48a, 50a, and 5211 respectively. It is to be noted that when the actuator 52a is in its extended position as indicated by dotted lines, the starboard outboard drive unit 20a and its corresponding propeller 22a are positioned to the right as viewed in FIG. 1. This is identical as that described with respect to port outboard drive unit 20. It is to be understood that the piston 52a may be easily coupled to the steering lever 24a in such a manner so as to have the propeller 22a positioned to the left when the piston is in its extended position.

The

throttle motor assemblies

34 and 34a are likewise structurally and functionally equivalent to the steering motor assembly 32, the reversible direct current motor, piston assembly, and actuator of throttle motor assembly 34 being designated by

numerals

54, 56 and 58 respectively while the reversible direct current motor, piston assembly, and actuator of the throttle motor assembly 34a being designated by

numerals

54a, 56a and 58:: respectively. The free end of piston 58 or rack is mechanically connected to the throttle arm 21 of engine 18 so as to drive the throttle arm 21 from its position as indicated in solid lines when the actuator is in its retracted position to a position as indicated in dotted lines when the actuator is in its extended position. As stated above, when the throttle arm is in its solid lined position, the engine 18 merely provides idle power and when the throttle arm is in its dotted lined position, the engine provides full power. It is to be understood that the engine power continuously increases as the throttle arm is driven from its solid lined position to its dotted lined position. The actuator 58a is mechanically coupled to the throttle arm 21a in the same manner for controlling the power output of engine 18a.

The

clutch motor assemblies

36 and 36a are also both structurally and functionally identical to steering motor assembly 32 and include respective reversible direct

current motors

60 and 60a, piston or

rack assemblies

62 and 62a, and

actuators

64 and 64a. The free end of actuator 64 is mechanically connected to the engageable clutch member 30 for driving the clutch member from its far left position, as viewed in FIG. 1, when the actuator is in its retracted position to the far right when the actuator is in its extended position and in an intermediate position when the end of the actuator is intermediate its retracted and extended positions. As stated above these three clutch positions represent forward engagement of the outboard drive unit 20 and engine 18, reverse engagement, and disengagement. The actuator 64a is mechanically coupled to the engageable clutch member 30a so as to provide the same function with respect to the inboard--outboard drive system 14 as actuator 64 provides with respect to inboard-- outboard drive system 12.

Now that a sufficient description has been given of each component required for maneuvering boat attention is directed to portable control box 42 for a discussion dealing with the control of each of the above described components for electronically controlling the maneuverability of boat 10. It is to be understood that each individual control mechanism on portable control box 42 is appropriately connected to the electronic circuitry required to control the various components as described above and that this electronic circuitry will be described in great detail subsequently.

The portable control box includes a steering wheel 66 and a switch 67 which may be referred to as a maneuvering switch. This switch is a two-position switch, one position being the cruise position and the other position being the maneuvering" position. The steering wheel 66 is appropriately coupled to the electronic circuitry so as to drive the pistons 52 and 52a of

steering motor assemblies

32 and 32a respectively when the steering wheel is turned either clockwise or counterclockwise as viewed in FIG. 1. This, of course, causes the

outboard drive units

20 and 20a respectively to pivot about venical pivots 26 and 26a.

When the maneuvering switch 67 is in the cruise position, the electronic circuitry is such that the

outboard drive units

20 and 20a are positioned parallel to each other and remain parallel to each other when the steering wheel is turned. That is to say, for example, when the steering wheel is turned clockwise the outboard drive units will concurrently pivot to the right as viewed in FIG. 1 and will pivot to the left when the steering wheel is turned counterclockwise.

When the maneuvering switch is flipped into the maneuvering position, a portion of the electronic circuitry is reversed as will be described hereinafter. As a result, when the wheel is turned clockwise both of the outboard drive units toe in, i.e., concurrently pivot towards each other, and will toe in until they reach the maximum position which is about 45 to the longitudinal axis 28 of the boat 10 or at about with respect to each other. This will also be the position at which the steering wheel can no longer be turned clockwise. When the steering wheel is turned counterclockwise until it can no longer be so turned, the outboard drive units will toe out, i.e., concurrently pivot away from each other until they reach their stop positions which again are at about 45 angles to the longitudinal axis 28 and at about 90 with respect to each other.

The portable control box 42 also provides a pair of throttle levers 68 and 68a which are appropriately connected to the electronic circuitry for driving throttle arms 21 and 21a respectively when the throttle levers are moved in a forward and rearward direction. Two clutch levers 70 and 700 are also provided, appropriately connected to the electronic circuitry, for driving engageable

clutch members

30 and 30a respectively into positions described above when the clutch levers are moved in upward and downward directions.

When the maneuvering switch is in the cruise position, the boat is steered and the throttles are actuated in the usual manner obtaining conventional but precise results. When the maneuvering switch is in the maneuvering position with the steering wheel turned clockwise as far as it can go so that both drive units are toed in, free maneuverability can be obtained. In this condition and with both clutches engaged in the forward position, the boat can be steered merely by differential operation of the throttle levers 68 and 680. In other words, if the right hand or starboard throttle 70a is advanced relative to the port throttle 70 so that engine 18a has greater output power than engine 18, the boat will turn to the right. As stated above, this is explained and broadly covered in US. Pat. No. 3,294,054.

When the drive units are toed in and with one engine engaged in reverse and the other in forward, and with the throttle levers actuated generally uniformly, the boat will turn about its center of drag. In other words, the boat will turn completely around within its own length. The direction of turn can be reversed by a turn of the steering wheel completely counterclockwise so that the drive units are toed out.

An interlock, which will be described with respect to FIG. 6, is provided between the throttle electronic circuitry and the clutch electronic circuitry so that the clutches cannot be shifted until the throttles have been returned to the idle position. In addition, a time delay electrical device is provided so that if the clutch switches have been shifted from one position to the other while the throttles are advanced no shifting will take place even when the throttles are returned to the idle position until after a small time delay which permits the engines to drop back to the correct speed before actual shifting takes place.

It is to be noted that the above described control system is adapted to be connected with the usual steering, throttle and gear shift controls of conventional structures.

Turning to FIG. 2, a block diagram of the electronic control circuit for controlling the throttles and steering of the boat is shown. An adjustable input circuit 72 is connected across a l2-volt direct current power supply (not shown) for developing a variable differential signal. In the case of the electronic steering circuitry the value of this differential signal is dependent upon the position of steering wheel 66 of FIG. 1 while in the case of the electronic throttle circuitry the differential signal value is dependent upon the position of throttle levers 68 and 68a. This differential signal is fed to an operational amplifier circuit 74 which both regulates and amplifies the differential signal. The output of the operational amplifier circuit, which is connected to a switching circuit 76, is referenced to a positive 6 volts and can swing either positive or negative from that value depending upon the sign of the differential input signal.

When for example, the steering wheel is turned in one direction the differential input signal is increased thus swinging the output of the operational amplifier circuit positive with respect to the above mentioned reference. When the steering wheel is turned in the opposite direction, the differential input signal is decreased causing the output of the operational amplifier circuit 74 to drop below the reference voltage. The output of switching circuit 76 is electrically connected to a motor I assembly circuit 78 which in the case of the electronic steering circuit includes the two reversible direct current motors 48 and 4811. When the output of the operational amplifier circuit is positive with respect to the 6 volts reference, the switching circuit allows the reversible motors to be forwardly driven for driving the

outboard drive units

20 and 20a in one direction as described with respect to FIG. 1. When the output of operation amplifier circuit 74 is below the 6 volts reference, the switching circuit allows the reversible motors to be reversely driven for driving the outboard drive units in an opposite direction. As stated above, the switching circuit includes a maneuvering switch which can adjust the switching circuit so as to drive the reversible direct current motors in opposite directions which causes the outboard drive units to be either toed in or toed out as described with respect to FIG. 1.

Separate electronic control circuitry is provided for the throttles and functions in the same manner as described above except that each portion of the circuitry controls only one reversible direct current motor included in motor assembly 78, that motor being either reversible direct

current motor

54 or 54a. When, for example, the throttle lever 68 is repositioned this either increases or decreases the value of the differential input signal depending upon which direction the throttle lever was moved. This variation in the differential input signal in turn either increases or decreases the output of the operational amplifier circuit with respect to its output reference voltage causing the switching circuit to allow the reversible direct current motor 54 to be driven in one direction or the other.

Turning to FIG. 3, a schematic view of an electronic control circuit 79 for steering boat 10 is shown. The circuit includes a l2-volt direct current source 80, an adjustable input circuit 82 electrically connected across the power supply 80, an operational amplifier circuit 84 electrically connected to the output of the adjustable input circuit, and a switching circuit 86 electrically connected to the output of the operational amplifier circuit.

The adjustable input circuit 82 includes a master potentiometer R5 and a slave potentiometer R6 fonning a part of a bridge circuit 87 across power supply 80. The adjusting arm 83 of potentiometer R5 is mechanically connected to the steering wheel 66 so as to be driven by the steering wheel causing the voltage across R6 to vary when the steering wheel causing the voltage across R5 to vary when the steering wheel is moved which in turn drives actuators 52 and 52a as described above. Potentiometer R6 likewise has an adjusting arm 85 which is mechanically connected to the steering actuators 52 and 52a for varying the voltage across R6 in proportion to the movement of the actuators as will be described hereinafter. Two resistors R1 and R2 connected in series across power supply divide the 12 volts supply so that 6 volts appear between resistors R1 and R2 and at the top of potentiometer R6 which has one end electrically connected intermediate resistors R1 and R2. A resistor R7 having one end electrically connected to the other side of potentiometer R6 with the other side of R7 connected to the negative side of power supply 70 is provided so that the range of voltage appearing across potentiometer R6 is about 3 volts. The voltage range of potentiometer R5 is also 3 volts or less depending upon the adjustment of potentiometers R3 and R4 which also form part of bridge circuit 87. Each of the potentiometers R3 and R4 has a

respective adjusting arm

86 and 83 electrically connected to a respective end of potentiometer R5. The potentiometers R3 and R4 are connected in series with the otherwise free end of potentiometer R3 electrically connected intermediate R1 and R6 and the otherwise free end of potentiometer R4 electrically connected through a resistor R19 to a point intermediate resistors R7 and potentiometer R6. Potentiometers R3 and R4 are used to adjust the range of travel of actuators 52 and 52a when potentiometer R5 is moved from one extreme position to the other which in turn is driven by moving steering wheel 66 as stated above. The slave potentiometer R6 is mechanically connected to the actuator in such a way that only about three turns of the lO-turn potentiometer are used for full range travel of the actuator. In other words, the adjusting arm will only move a distance equal to threetenths that of the entire distance of potentiometer R6 when the actuators 52 and 52a are moved from one extreme position to the other as described with respect to FIG. 1. Therefore, about seven-tenths of the resistance of the potentiometer R6 appears in the circuit as if it were a fixed resistance. Resistor R19 is provided within the bridge 87 to match this unvarying portion of potentiometer R6. A resistor R8 has one end electrically connected to the actuating arm 85 of potentiometer R6 and its otherwise free end connected to the negative input terminal of an operational amplifier 90 which will be described hereinafter. A resistor R9 electrically connects the adjusting arm 83 to the positive input terminal of operational amplifier 90. The two resistors R8 and R9 are provided so as to utilize the voltages across potentiometers R5 and R6 as a differential input signal which is to be fed to the input of operational amplifier 90.

The operational amplifier circuit 84 includes an operational amplifier 90 having negative and positive input terminals respectively designated by numerals 1 and 2, an output terminal designated by the numeral 3 and additional terminals designated by the

numerals

4, 5, 6 and 7 respectively. The operational amplifier circuit also includes an adjustable resistor R10 connected at one end to the output terminal 3 of the operational amplifier 90 with its otherwise free end connected intermediate resistor R8 and negative input terminal 1. The resistor R10 provides conventional negative feedback for the operational amplifier. The amplifier gain is determined approximately by the values of resistors R8 and R10. The operational amplifier 90 is a conventional RCA No. CA 3029 type amplifier and reference is made to the RCA handbook RCA Linear Integrated Circuits (technical series IC-41) for a detailed discussion of the amplifier. It is to be understood, of

course, that other operational amplifiers providing the same function as described below may be substituted therefor. A resistor R11 and a capacitor C2 connected in series, are provided to form a phase compensation network for the operational amplifier. This series circuit has one end connected to terminal 4 of the operational amplifier and its otherwise free end connected intermediate resistors R1 and R2. The terminal 5 of the operational amplifier is connected to the otherwise free end of resistor R11 and the terminal 7 is connected to the negative side of power supply 80. The output of the operational amplifier is referenced to a positive six volts as discussed below and can swing either above or below that value depending upon the sign of the differential input signal. That is to say that the output of operational amplifier depends upon whether the voltage across R9 is greater or less than the voltage across R8. A resistor R18 is electrically connected at one end intermediate resistor R9 and positive input terminal 2 of the operational amplifier, the otherwise free end of resistor R18 being connected intennediate resistors R1 and R2. R18

has been included in the circuit for the sake of completeness. In practice, it has not been used and is not essential in this application.

The switching circuit 86 includes an NPN transistor Q1 and PNP transistor Q2 each of which has its base connected to the output of operational amplifier 90 and its emitter connected to the emitter of the other transistor. The collector of transistor Q1 is connected to the positive side of the power supply 80 through two biasing resistors R12 and R13 while the collector of Q2 is connected to the negative side of power supply 80 through biasing resistors R14 and R15. The emitters of both transistor Q1 and Q2 are also connected intermediate resistors R1 and R2 so that the emitters are maintained at six volts, the output reference voltage ofthe operational amplifier 90 as referred to above. The second NPN transistor O3 is connected across the power supply 80 with its base connected intermediate resistors R14 and R15, its emitter connected to the negative side of the power supply, and its collector connected to the positive side of the power supply through an electromagnetic relay K1. A second electromagnetic relay K3 is connected across the electromagnetic relay Kl. It is to be understood that the electromagnetic relays herein referred to, are conventional relays having electromagnetic coils which when energized open or close normally closed or opened associated contact. When reference is made to the relay itself what is meant is the electromagnetic coil. A second PNP type transistor O4 is also connected across the power supply 80 having its base connected intermediate resistors R12 and R13, its emitter connected to the positive side of power supply 80, and its collector connected to the negative side of power supply 80 through an electromagnetic relay K2. A fourth electromagnetic relay K4 is connected across relay K2. The electromagnetic relays K1, K2, K3 and K4 are also electrically tied to a wafer type switch 92 which may be actuated by maneuvering switch 67 such that electromagnetic relay K3 is electrically connected across K2 and that electromagnetic relay K4 is connected across K1 for reasons described below.

The transistor Q3 has a filtering circuit connected across its collector and emitter comprising a capacitor C4 and resistor R17 connected in series while the transistor 04 has a filtering circuit connected across its collector and emitter comprising capacitor C3 and resistor R16 connected in series. The electromagnetic relays K1, K2, K3 and K4 have respective contacts K1, K2, K3 and K4 which are electrically connected to reversible direct

current motors

48 and 48a and will be described with respect to Fig. 4.

The electronic control circuit 79 of FIG. 3 includes a capacitor C1 electrically connected across the resistors R1 and R2 so as to prevent a drain of power from supply 80 when reversible direct

current motors

48 and 48a are initially energized as described below. A diode D1 having its anode connected to the positive side of the power supply 80 and its cathode connected to the remainder of the electronic circuit 79 is provided to block the discharging of capacitor C1 by the motor load. It also protects the circuit against accidental application of the wrong polarity.

In operation, when the steering wheel 66 is maintained such that the

outboard drive units

20 and 20a are positioned parallel to the longitudinal axis 28 of boat 10 equal voltages appear across potentiometers R5 and R6 causing a differential input signal of zero to appear at the input of operational amplifier 90. The emitters of transistors Q1 and Q2 are therefore maintained at 6 volts reference causing the transistors to be in a nonconductive state. This in turn prevents either of the transistors Q3 or Q4 from being in a conductive state. As long as the transistors Q3 and Q4 remain in a nonconductive state, the electromagnetic relays K1, K2, K3 and K4 remain in a deenergized condition which prevents the

reversible motors

48 and 48a from driving their respective outboard drive unit as will be described with respect to FIG. 4.

When, for example, the steering wheel 66 is turned clockwise the voltage across potentiometer R5 increases causing the bridged circuit 87 to be unbalanced and thus a positive differential input signal appears at the input of operational amplifier 90. This in turn increases the output of the operational amplifier with respect to its six volts reference causing transistor O1 to conduct. With Q1 conducting, transistor 04 is properly biased, allowing electromagnetic relays K2 and K4 to be energized. As will be described with respect to FIG. 4, this causes

reversible motors

48 and 48a to be simultaneously driven in forward directions so that their respective actuators 52 and 52a move to extended positions. The

outboard drive units

20 and 20a will in turn be pivoted to the right as viewed in FIG. 1. When the steering wheel is no longer turned, such that the voltage across potentiometer R5 is maintained at a value greater than the voltage across potentiometer R6, the adjusting arm is repositioned by its mechanically connected actuators 52 and 52a such that bridge circuit 87 is again balanced. This in turn drives the differential input signal to a value of zero causing the

reversible motors

48 and 48a to be de-energized.

Similarly, if steering wheel 66 is turned counterclockwise reducing the voltage across potentiometer R5 a negative differential input signal appears at the input of operational amplifier 90 causing Q2 and O3 to conduct which in turn energizes electromagnetic relays K1 and K3 causing the

reversible motors

48 and 48a to be driven such that the

outboard drive units

20 and 20a are pivoted to the left as viewed in FIG. 1. When the steering wheel is no longer turned, the potentiometer R6 is again repositioned such that a differential input signal of zero appears at the input of operational amplifier 90 causing the reversible motors to be de-energized and stopping

outboard drive units

20 and 20a.

Turning to FIG. 4, the reversible direct current motor 48 has its positive or forward side connected to electromagnetic relay contact K2 and its negative or reverse side connected to electromagnetic relay contact K1. When the electromagnetic relays K1 and K2 are in their de-energized state, the contacts K1 and K2 connect reversible motor 48 to ground as indicated by a solid line representation in FIG. 4. When the electromagnetic relay K2 is energized, the contact K2 is moved to its dotted line position. This connects the reversible motor 48 to a l2-volt direct current source such that the motor is driven in a forward direction so as to function as described above. When the electromagnetic relay K1 is energized, contact K1 is moved to its dotted line position such that the reversible motor 48 is driven in a reverse direction. Reversible motor 480 is electrically connected to a 12-volt DC power supply in the same manner as reversible motor 48 such that motor 48a is driven in a forward direction when electromagnetic relay K4 is energized and in a reversed direction when electromagnetic relay K3 is energized.

The above discussion assumes that maneuvering switch 67 is in its cruise position. If the switch is thrown to its maneuvering" position causing electromagnetic relay K3 to be connected to K2 and K4 to be connected to K1 the operation will be the same except that motor 48a will be driven in an opposite direction from that of motor 48. This in turn will cause a toeing in and toeing out of drive units 20 and 200 as described with respect to FIG. 1.

It is to be understood that reversible direct current motors 48 and 480 may utilize their own electronic control circuit 79 as described in FIG. 3. In such a case, a potentiometer R of each circuit would be mechanically connected to the steering wheel 66 such that each of the potentiometers actuating arms 82 would be moved equally and simultaneously. It is to be further understood that the l2-volt direct current power supply 80 may be used to power the

reversible motors

48 and 48a in addition to the electronic circuitry of FIG. 3 rather than using separate power supplies as indicated in FIG. 4.

Turning to FIG. 5, an electronic control circuit for the throttle arm 21 is shown. This circuit functionally and structurally is similar to that circuit disclosed with respect to FIG. 3 with exceptions indicated below. Electrical components of the electronic circuitry of FIG. 5 which are equivalent to those components of FIG. 3 are designated with like numerals in addition to a suffix a.

The first electrical difference between the two circuits is that potentiometer R19 replaces resistors R19, R3 and R4. The potentiometer R19 serves to limit the range of travel of actuator 58 for a given range of travel of the master potentiometer R50. As stated above, this function was provided by potentiometers R3 and R4 of electronic control circuit 79 of FIG. 3. The actuating arm 96 of potentiometer R19 is electrically connected to the negative side of power supply 80a through resistor R7a. A second difference is that a zener diode D2 has been added, which diode is electrically connected intermediate variable resistor R10 and input terminal 1 of the operational amplifier 90. Thirdly, resistors R16 and R17 and capacitors C3 and C4 have been eliminated along with resistor R18. Finally, electromagnetic relays K3 and K4 have been eliminated so that the electronic circuit controls only one reversible direct current motor which as shown in FIG. 5 is the throttle reversible motor 54.

In operation, when the throttle lever 68 is maintained in its idle position equal voltages appear across potentiometers R5 and R6 which as in the case of electronic control circuit 79 causes transistors 01, Q2, Q3 and O4 to be off which in turn maintains electromagnetic relays K1 and K2 is their de-energized state so that reversible motor 54 is de-energized. When the throttle lever is forwardly moved, the voltage across potentiometer R5 increases so that reversible motor 54 is forwardly driven causing actuator 58 to drive throttle arm 21 as described with respect to FIG. 1. The motor 54 is de-energized when the voltage across potentiometer R6 goes to a value such that the differential input signal appearing at the input of operational amplifier 90 is equal to zero as in the case of circuit 79. The reversible direct current motor 54 may be reversed in the same manner as described with respect to the electronic control circuit 79.

It is to be understood that a circuit equivalent to that described with respect to FIG. 5 is provided for the throttle arm 21a and is actuated in the same manner by throttle lever 1580.

Turning to FIG. 6, an electronic control circuit 100 for controlling the engageable clutch member as described in FIG. 1 is connected across a l2-volt direct current power supply 102. The electronic control circuit 100 includes a wafer shaped switch 104 which is mechanically coupled to the clutch actuating motor 60, of the clutch motor assembly 36 so as to function as described below. The wafer switch 104 has two conductive portions 106a and l06b each of which substantially comprises a respective half of the wafer switch. The conductive portions may be made from copper or like conductive material. The wafer also has two wedge shaped insulating or

nonconductive portions

108a and 108b each of which extends from an opposite outer edge of the wafer and meets at the center thereof. The nonconductive portions separate the two conductive portions 106a and 106k.

The electronic control circuit 100 also includes a threeposition switch 110 having three positions indicated by the letters F, N and R respectively and a movement arm indicated by the numeral 112. The point about which movement arm 112 pivots is electrically connected to the negative side of power supply 102 through a switch 114 and a timing switch 116. The

switches

114 and 116 are operably connected to the throttle lever 68 by means not shown and function in a manner described below. The F or forward position of switch 110 is slideably and electrically connected to the wafer switch 104 by tap member 118. The tap 118 is positioned adjacent the lower left hand quadrant of wafer switch 104 as viewed in FIG. 6 such that the tap maintains contact with the wafer switch when the wafer switch is rotated as described below. The R or reverse position of switch 110 is connected to the lower right quadrant of wafer switch 104 by tap member 120 in the same manner as described with respect to tap member 118. The N position of switch 110 is likewise slidably and electrically connected to the wafer switch 104 by tap member 122. The tap member 122 is positioned on the wafer switch

intermediate taps

118 and 120.

The electronic circuit 100 also includes electromagnetic relays K5 and K6 each of which has one end connected to the positive side of power supply 102. The otherwise free side of electromagnetic relay K5 is slideably and electrically connected to wafer switch 104 by tap member 124 at a point adjacent to tap member 118. The otherwise free side of electromagnetic relay K6 is likewise connected to wafer switch 104 by tap member 126 which is positioned adjacent tap member 120. Each of the electromagnetic relays, K5 and K6, have respective contacts K5 and K6 which are connected respectively to the forward and reverse sides of reversible direct current motor 60, reversible direct motor 60 being the motor for controlling the engageable clutch member 30 as described in FIG. 1. The contacts K5 and K6 connect reversible motor 60 to ground when their respective electromagnetic relays are de-energized. This is indicated by a solid line representation of K5 and K6 in FIG. 6. The dotted line representation of contacts K5 and K6 indicate the positions of these contacts when their respective electromagnetic relays are energized and will control reversible motor 60 as described below.

In operation, when the clutch lever is positioned such that engine 18 and outboard drive unit 20 are disengaged as described with respect to FIG. 1, switch 110 which is mechanically coupled to clutch lever 70 is positioned in its N position as seen in FIG. 6. This disconnects both electromagnetic relays K5 and K6 from power supply 102. As seen in FIG. 6 the wafer switch 104 is positioned such that its nonconductive portion 10% is in contact with tap member 122.

When it is desired to forwardly engage engine 18 and outboard drive unit 20 the clutch lever 70 is positioned such that switch 110 is in its F position. This closes the circuit through electromagnetic relay K5 such that the current from power supply 102 will pass through electromagnetic relay 1(5 and thereafter to the negative side of the power supply through tap member 124, conductive portion 106a of wafer switch 104 and tap member 118, energizing electromagnetic relay 16. This is, of course, assuming that

switch

114 and 116 are closed. These switches are coupled to throttle lever 68, by means not shown, such that switch 114 is closed only when the throttle lever is in its idle position and switch 116 is energized at the same time so as to close its contact a predetermined period of time after the throttle lever has been positioned in its idle position. The reason for the time delay is so that the engine 18 can drop back to its idle speed before actual shifting takes place.

With electromagnetic relay K5 energized contact K5 is positioned, as indicated in dotted lines so as to connect the forward side of reversible motor 60 to a 12 volt power supply. This drives reversible motor 60 forwardly, as described in FIG. 1, for forwardly engaging engine 18 and outboard drive unit 20. As the motor 60 is forwardly driven, the motor drives its mechanically connected wafer switch 104 so as to move in a counterclockwise direction as viewed in FIG. 6 until non-conductive portion 108a encompasses

tap members

118 and 124. This disconnects the circuit through electromagnetic relay K5, de-energizing electromagnetic relay K5 and reversible motor If it is desired to reversely engage engine 18 and outboard drive unit 20, clutch lever 70 is moved such that switch 110 is in its R position for energizing electromagnetic relay K6. In such a position, current from power supply 102 passes through electromagnetic relay K6, tap member 126, conductive portion 106a of wafer switch 104 which is now positioned under

taps

120 and 126, tap member 120 and ultimately to the negative side of power supply 102. This again is assuming that throttle lever 68 is positioned such that

switches

114 and 116 are closed. With electromagnetic relay K6 energized, contact K6 is positioned as indicated in dotted lines such that reversible motor 60 is reversely driven by the 12 volt power supply for appropriately driving mechanical clutch member 30 as described with respect to FIG. 1.

As motor 60 is reversely driven, wafer switch 104 is driven clockwise. When nonconductive portion 108b encompasses

tap members

120 and 126, the circuit through electromagnetic relay K6 is again opened de-energizing K6 and reversible motor 60. The engine 18 and outboard drive unit 20 are now reversely engaged.

If it is finally desired to disengage the engine and drive unit, clutch lever 70 is appropriately positioned such that switch 110 is again in its N position so as to energize electromagnetic relay K5. In this situation the current from power supply 102 passes through electromagnetic relay K5, tap member 124, conductive portion 106 of wafer switch 104 which now is positioned under the

tap members

118, 122 and 124, tap member 122 and thereafter to the negative side of power supply 102. This ultimately causes the wafer switch again to be driven counterclockwise until nonconductive portion l08b is positioned under tap member 122 for disconnecting the switch.

It is to be understood that an electronic control switch circuit similar to that described with respect to FIG. 6 is provided for the clutch controls of inboard--outboard drive system 14 and actuated by clutch lever 70a.

While a particular embodiment of the invention has been shown, it should be understood, of course, that the invention is not limited thereto since many modifications may be made, and it is, therefore, contemplated to cover by the appended claims any such modifications that fall within the true spirit and scope of the invention.

What is claimed is:

1. A control circuit for steering a boat powered by engine means including an engine and a drive unit, said drive unit being pivotal about an upstanding axis and having propeller means, said control circuit comprising: a source of electrical power; adjustable input circuit means electrically connected across said source of power for developing a variable differential signal; means for varying said differential signal from a predetermined value; an operational amplifier circuit electrically connected to the output of said input circuit means for amplifying said variable differential signal; and circuit switching means electrically connected to the output of said amplifier circuit and operatively connected to said drive unit, said circuit switching means responsive to a variation from said predetermined differential signal for pivoting said drive unit about said axis whereby steering of said boat is accomplished 2. A control circuit according to claim 1 wherein said input circuit means includes a first variable resistor electrically connected across said source of power for developing a first voltage; a second variable resistor electrically connected across said first resistor for developing a second voltage; means electrically connected to said first and second resistors, combining said first and second voltages for developing said differential signal; means electrically connected to said first resistor for varying said first voltage thereby varying said differential signal from said predetermined value whereby said drive unit is pivoted about said axis; and means electrically connected to said second resistor and operatively connected to said drive unit whereby the pivoting of said drive unit varies said second voltage proportional to the variation of said first voltage for restoring the differential signal to said predetermined value and stopping said drive unit.

3. A control circuit according to claim 2 including reversible motor means electrically connected to said circuit switching means and operatively connected to said drive unit for pivoting said drive unit, said motor means being responsive to a positive variation from said predetermined value for pivoting said drive unit in one direction and responsive to a negative variation from said predetermined value for pivoting said drive unit in an opposite direction.

4. A control system for steering a boat powered by engine means including an engine and a drive unit, said drive unit being pivotal about an upstanding axis and having propeller means, said control circuit comprising: a source of electrical power, a resistance bridge circuit having first and second variable resistance elements, an operational amplifier having first and second input terminals for receiving electrical signals from said first and second variable resistance elements respectively, and further having an output terminal for producing a predetermined reference potential when the electrical signals from said first and second variable resistance elements are the same value and for producing a potential different than said reference potential when the electrical signals from said first and second variable resistance elements are of different values, first and second switch circuit means coupled to the output of said operational amplifier, said first switch circuit means being responsive when the potential at the output terminal of said operational amplifier is above said reference potential and said second switch circuit means being responsive when the potential at the output of said operational amplifier is below said reference potential, and motor means operatively connected to said drive unit and responsive to said first and second switch circuit means for pivoting said drive unit about said upstanding axis for steering the boat,

5. The control system according to claim 4 further including first and second transistors of opposite conducting types with their emitters tied togedier and their collectors connected across said source of electrical power, the output terminal of said operational amplifier being connected to the base electrodes of said first and second transistors, a second reference potential connected to the emitters of said first and second transistors, said second reference potential being substantially equal to the reference potential developed at the output terminal of said operational amplifier thereby maintaining said first and second transistors non-conductive, whereby a decrease in the reference potential at the output terminal of said operational amplifier will cause said first transistor to be rendered conductive and an increase in the reference potential at the output terminal of said operational amplifier will cause said second transistor to be rendered conductive to operate said first and second switch circuit means, respectively.

6. In a control system for a boat, the combination including, lever means, motor means operatively connected to said lever means to actuate the same for controlling a function of the boat for maneuvering, a source of electrical power, a resistance bridge circuit having first and second variable resistance elements connected across said source of electrical power, an operational amplifier having first and second inputs for receiving electrical signals from said first and second variable resistance elements respectively, and further having an output for producing a predetermined reference potential when the electrical signals from said first and second variable resistance elements are of the same value and for producing a potential different than said reference potential when the electrical signals from said first and second variable resistance elements are of a different value, first and second switch circuit means coupled to the output of said operational amplifier, said first switch circuit means being responsive when the potential at the output of said operational amplifier is above said reference potential and said second switch circuit means being responsive when the potential at the output of said operational amplifier is below said reference potential, and means connecting said switch means to said motor means for operating the same in one or the other direction, depending on which switch means is actuated, for moving said lever means.

Ina/n n...

equal to the reference potential developed at the output of said operational amplifier thereby maintaining said first and second transistors non-conductive, whereby a decrease in the reference potential at the output of said operational amplifier will cause said first transistor to be rendered conductive and an increase in the reference potential at the output of said operational amplifier will cause said second transistor to be rendered conductive to operate said first and second switch circuit means, respectively.

Claims

1. A control circuit for steering a boat powered by engine means including an engine and a drive unit, said drive unit being pivotal about an upstanding axis aNd having propeller means, said control circuit comprising: a source of electrical power; adjustable input circuit means electrically connected across said source of power for developing a variable differential signal; means for varying said differential signal from a predetermined value; an operational amplifier circuit electrically connected to the output of said input circuit means for amplifying said variable differential signal; and circuit switching means electrically connected to the output of said amplifier circuit and operatively connected to said drive unit, said circuit switching means responsive to a variation from said predetermined differential signal for pivoting said drive unit about said axis whereby steering of said boat is accomplished.

2. A control circuit according to claim 1 wherein said input circuit means includes a first variable resistor electrically connected across said source of power for developing a first voltage; a second variable resistor electrically connected across said first resistor for developing a second voltage; means electrically connected to said first and second resistors, combining said first and second voltages for developing said differential signal; means electrically connected to said first resistor for varying said first voltage thereby varying said differential signal from said predetermined value whereby said drive unit is pivoted about said axis; and means electrically connected to said second resistor and operatively connected to said drive unit whereby the pivoting of said drive unit varies said second voltage proportional to the variation of said first voltage for restoring the differential signal to said predetermined value and stopping said drive unit.

4. A control system for steering a boat powered by engine means including an engine and a drive unit, said drive unit being pivotal about an upstanding axis and having propeller means, said control circuit comprising: a source of electrical power, a resistance bridge circuit having first and second variable resistance elements, an operational amplifier having first and second input terminals for receiving electrical signals from said first and second variable resistance elements respectively, and further having an output terminal for producing a predetermined reference potential when the electrical signals from said first and second variable resistance elements are the same value and for producing a potential different than said reference potential when the electrical signals from said first and second variable resistance elements are of different values, first and second switch circuit means coupled to the output of said operational amplifier, said first switch circuit means being responsive when the potential at the output terminal of said operational amplifier is above said reference potential and said second switch circuit means being responsive when the potential at the output of said operational amplifier is below said reference potential, and motor means operatively connected to said drive unit and responsive to said first and second switch circuit means for pivoting said drive unit about said upstanding axis for steering the boat.

5. The control system according to claim 4 further including first and second transistors of opposite conducting types with their emitters tied together and their collectors connected across said source of electrical power, the output terminal of said operational amplifier being connected to the base electrodes of said first and second transistors, a second referEnce potential connected to the emitters of said first and second transistors, said second reference potential being substantially equal to the reference potential developed at the output terminal of said operational amplifier thereby maintaining said first and second transistors non-conductive, whereby a decrease in the reference potential at the output terminal of said operational amplifier will cause said first transistor to be rendered conductive and an increase in the reference potential at the output terminal of said operational amplifier will cause said second transistor to be rendered conductive to operate said first and second switch circuit means, respectively.

7. The control system according to claim 6 further including first and second transistors of opposite conductivity type with their emitters tied together and their collectors connected across said source of electrical power, the output of said operational amplifier being connected to the base electrodes of said first and second transistors, a second reference potential connected to the emitters of said first and second transistors, said second reference potential being substantially equal to the reference potential developed at the output of said operational amplifier thereby maintaining said first and second transistors non-conductive, whereby a decrease in the reference potential at the output of said operational amplifier will cause said first transistor to be rendered conductive and an increase in the reference potential at the output of said operational amplifier will cause said second transistor to be rendered conductive to operate said first and second switch circuit means, respectively.