US 3811394 A
A control unit with means to provide a positive connection between a rudder and a power driving motor for automatic pilot steering. The control unit is normally attached to a steering means, such as a quandrant, which is keyed to a rudder post. The control unit has rotatable means responsive to a shaft extending from the power motor, including a sprocket which engages a detent carried by a pivotal braking arm. The arm is movable between either a release or set position. A solenoid having a plunger element is provided which extends through the distal end of the arm to effect movement of the braking arm into set position. Resilient means, such as springs, surround the plunger on either side of the brake arm and bias it either into set position when the solenoid is activated or release position when inactivated. Provision is also made for manual override of the automatic control. When the unit is in set position, the reciprocating movement of the shaft from the power motor will cause a corresponding movement of the quadrant and, ultimately, the rudder. In release position, the movement of the shaft will not affect the quadrant.
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Description (OCR text may contain errors)
United States Patent [191 Lathers  3,811,394 [451 May 21, 1974 CONTROL UNIT Paul Anthony Lathers, North Scituate, R1.
 Assignee: Unipas, Inc., Cranston, RI.
 Filed: Mar. 23, 1972  Appl. No.: 237,456
 References Cited UNITED STATES PATENTS 9/1971 Arce ll4/l44 R 2/195] Holmes 1 14/144 R Primary Examiner-Milton Buchler Assistant Examiner-Charles E. Frankfort  ABSTRACT A control unit with means to provide a positive connection between a rudder and a power driving motor for automatic pilot steering. The control unit is normally attached to a steering means, such as a quandrant, which is keyed to a rudder post. The control unit has rotatable means responsive to a shaft extending from the power motor, including a sprocket which engages a detent carried by a pivotal braking arm. The arm is movable between either a release or set position. A solenoid having a plunger element is provided which extends through the distal end of the arm to effect movement of the braking arm into set position. Resilientmeans, such as springs, surround the plunger on either side of the brake arm and bias it either into set position when the solenoid is activated or release position when inactivated. Provision is also made for manual override of the automatic control. When the unit is in set position, the reciprocating movement of the shaft from the power motor will cause a corresponding movement of the quadrant and, ultimately, the rudder. In release position, the movement of the shaft will not affect the quadrant.
9 Claims, 7 Drawing Figures PATENTEDIAYZ'I 1924 3.81 IL 394 SHEET 2 BF 2 7 FIG. 4.
CONTROL UNIT BACKGROUND OF THE INVENTION This invention relates to automatic pilots and more particularly to a control unit for automatic pilot steering systems which is adapted to provide for either manual or automatic operation of the system. Automatic pilots have been known for years and have been the subject of intensive development but the products resulting of this development have been costly devices which are complex in nature and generally inappropriate for use in small craft. Installation of such automatic pilots is generally complicated and, thus, impractical for widespread use. For example, in the usual automatic control system a clutching arrangement is provided so that the system may alternate between manual or automatic control. While such an arrangement may provide effective control, its placement in a small craft is costly and impractical. In other systems a hook-up is provided between the manual steering mechanism and the power apparatus control so that no clutching or declutching is necessary. However, this hook-up is generally fitted into a steering cable or rod which in certain instances may be inconvenient to get to and also results in a costly installation.
SUMMARY OF THE INVENTION Accordingly, it is a particular object of this invention to provide a control unit for an automatic pilot system which is simple in design and may be conveniently installed in automatic pilot systems for small craft.
It is another object ofthis invention to provide a control unit for an automatic pilot steering system which may be activated for sensitive reaction to small course changes and yet adapted to override by a simple and convenient manipulation of manual steering controls when required.
Other objects and embodiments will become apparent from the following disclosure.
The invention comprises a control unit which allows either manual or automatic control of a rudder. The unit comprises an actuator means which is pivotally attached to a steering means mounted on a post supporting the rudder. The steering means is positively connected to a manual steering mechanism. Located within the actuator means is a releasable member which when in set position, through a connecting element, locks the actuator means and, utimately, the steering means and rudder to a power driving means. When the releasable member is in its inactive or released position, the actuator means functions independant of the power means. Thus, the steering means will respond only to the manual steering mechanism. The actuator means is also adapted for over-ride of its automatic function in set position by the manual steering mechanism when so dictated by circumstances.
BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate the best mode presently contemplated for carrying out the objects of the invention and are not to be construed as restrictions or limitations on its scope. In the drawings:
FIG. I is a side elevation of the control unit showing the actuator with a portion of its housing cut away and embodied in connection with a conventional reversible motor.
FIG. 2 is a top plan view of the system of FIG. 1 showing the motor connecting element in its fully extended position.
FIG. 3 is a top plan view of the system of FIG. 1 showing the motor connecting element in its fully retracted position.
FIG. 4 is a top plan view of the system of FIG. 1 wherein the actuator moves independant of the reversible motor.
FIG. 5 is a fragmentary enlarged view of the actuator of FIG. 4 along lines 55 showing the releasable element in its released position.
FIG. 6 is a fragmentary enlarged view of the actuator of FIG. 1 showing the releasable element in its override position.
FIG. 7 is a view along lines 7-7 of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, a quadrant 10 is keyed to a rudder post 11 so that its axis of swing is the center of the post. As seen better in FIG. 2, the quadrant has an arcuate outer edge 12 provided with tracks 13 and 14 which receive cables 15 and 16. The cables are each secured at one end at flange portions 18 and 19 respectively and connected at the other ends, either directly or indirectly, to a manual steering mechanism, not shown. An actuator unit, generally designated 20, is shown with a portion of its housing 21 cut away. As seen in greater detail in FIGS. 5 and 6, the actuator is pivotally supported on a pivot 22 at a point intermediate bars 23 and 24 which are clamped together by any convenient means such as the nut and bolt arrangement as shown in FIG. 5. The pivot extends through the bars and a spacer 25 and is secured by nut 26. Contained within the actuator housing is a releasable member or brake arm 27, having stems 28 and 29 shown in FIG. 7 which are pivotally supported at one end on a fixed axis by pin 9, which is secured to the housing 21, and joined at the distal ends by an aperatured spacer 30. A solenoid 31, mounted in the bottom portion of the housing 21,- has a plunger element 32 extending therefrom through the aperature in spacer 30. Attached to the end of plunger 32 is a retainer disc 33. Compression springs 34 and 35 surround the plunger on either side of brake arm 27 and bias the arm either away from the solenoid when it is inactivated as viewed in FIG. 6, or away from the retainer disc 33 when activated. At an intermediate point on arm 27 is a roller 36 which acts as a detent when engaging the teeth of a sprocket 37. The sprocket is mounted along with a pinion 38 (shown in phantom), on a shaft 39 which is secured to the side of the housing 21 as seen in FIG. 7.
In FIG. 1, a power driving unit 40 is shown pivotally mounted on the underside of the stern portion of a vessel. The power unit consists of a housing 41 containing a reversible motor, not shown, and a shaft 42 which is driven by the motor through a gearing mechanism, also not shown, in the base of the unit. The shaft 42 acts as a connecting element between the power unit and the actuator and is adapted to be reciprocated into and out of the power unit so as to adjust its position in accordance with a predetermined signal from a direction sensing device which energizes the motor. Formed at the outer portion of the shaft 42 is a rack 43 which ex- -tends through an opening in the side of the housing 21 and meshes with the pinion 38.
When automatic pilot steering is desired, the solenoid 31 is activated from an external source whereupon an electromagnetic field is produced which attracts the plunger 32 thereby forcing compression of spring 34 which biases the brake arm 27 so that it moves forward and compresses spring 35. As previously indicated, this forward movement of the brake arm 27 causes the roller 36 to engage the teeth of sprocket 37 and prevent its rotation. When so engaged, by reason of the rack and pinion connection between the power unit 40 and the actuator 20, any reciprocating motion of the shaft 42 extending from the power motor will be transmitted to the quadrant l and in turn the rudder. For manual operation the solenoid is inactivated, again from an external source, whereupon spring 35 will bias the brake arm away from the sprocket 37 which will then be free to rotate unhindered by roller 36 as seen in FIG. 5. When the brake arm is in this position, the reciprocating motion of the shaft 42 and its rack portion 43 will not be transmitted to the quadrant as illustrated in FIG. 4
1 In FIG. 2 the invention is illustrated in the condition opposite to that illustrated in FIG. 2.
During operation of the automatic pilot it may occasionally be necessary to take over manual control for a short time to perform a dodging maneuver or for some other reason. As seen in FIG. 6 the present invention is adapted to provide for such an override feature.
As previously indicated, when activated, the: solenoid 3| attracts plunger 32 so that spring 34 is biased by retainer disc 33 against arm 27. Thus, force is created which presses the arm forward so that roller 36 is sealed in one of the spaces between the teethon sprocket 37 and restrains it from rotation. However, in response to a force exerted by the manual steering mechanism the quadrant 10 may be rotated about its axis causing an overload torque on sprocket 37 thereby unseating the roller in the brake arm from its set position. The reverse force caused by the roller overriding the teeth of the sprocket will cause slight backward movement of the arm 27 so that spring 34 is further compressed. When the overload torque is no longer present, spring 34 will force brake arm 27 back into its set position thereby restraining sprocket 37 against rotation and effecting automatic control once more.
Of course, other variations of the specific construction and arrangement of the control unit disclosed above can be made by those skilled in the art without departing from the invention as defined in the appended claims.
What is claimed is: r
I. In a vessel having means for operating a rudder post. steering means mounted on said post and positively connected to a manual steering mechanism, actuator means pivotally attached to said steering means, power driving means pivotally mounted on a support laterally spaced from said steering means, and including shaft means adapted at one'end to laterally reciprocate into and out of said power driving means and providing a positive connection at its opposite end with said actuator means, said actuator means including a releasable member adapted when held in set position to render said connection operative and permit the operation of said steering means independent of said manual steering mechanism, said releasable member being yieldable in set position to an'override force from said manual steering mechanism.
2. The invention as identified in claim 1 wherein said steering means is a quadrant.
3. The invention as defined in claim 2 wherein said actuator further includes a rotatable means operable to maintain said positive connection operative when held against rotation by said releasable member.
4. The invention as defined in claim 3 wherein said actuator includes electromagnetic means to effect relative movement of said releasable member from a release position to a set position.
5. A convertible manual and automatic control unit adapted to provide a positive connection between a steering means and a power driving means laterally spaced from said steering means, comprising a housing, mounting means to pivotally mounted said housing on said steering means, rotatable means mounted in said housing, said rotatable means including an element having a plurality of teeth arranged in a circular series, said element being adapted when held against rotation to maintain said connection and when permitted to rotate to render said connection ineffectual, a braking member adapted when held in set position to hold said element against rotation, but movable to a release position, and electromagnetic means including resilient elements to bias said braking member into set position when activated and release position when inactivated.
6. A control unit as defined in claim 5 wherein said braking member is movable from a set position in response to an overriding torque in said rotatable element.
7. A control unit as defined in claim 6 wherein said electromagnetic means is a solenoid.
8. A convertible manual and automatic control unit adapted to provide a positive connection between a steering means and a power driving means laterally spaced from said steering means, comprising a housing, mounting means adapted to pivotally mount said housing on said steering means, a rotatable element having a plurality of teeth arranged in a circular series mounted in said housing, said element being adapted to mesh with one end of shaft means reciprocally and laterally'movable in said power driving means so that when held against rotation said connection is'maintained and when permitted to rotate said connection is rendered ineffectual, a braking member pivotally secured at one end to said housing and movable between release and set position, a detent member carried by said braking member and acting to hold said rotatable element against rotation when in set position, electromagnetic means secured in said housing to effect relative movement of said detent from one of said release or set positions.
9. A control unit as defined in claim 8 wherein said electromagnetic means includes a plunger movable in response to a magnetic field generated in said electromagnetic means, and resilient means surrounding said plunger and biasing said braking member into one of said set or release positions in response to the activation or inactivation of said magnetic field.
I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,811,394 Dated 5/21/74 Inventor) Paul Anthony Lathers It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 3, line 42, instead of "sealed" should be seated.
Signed and sealed this 17th day of September 1974.
MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents H M PO 1050 (10 69) uscoMM-DC sows-ps9 9 us. GOVERNMENT PRINTING OFFICE: I969 O'366334.