US2541217A - Arrangement for automatically steering a ship on a predetermined course - Google Patents

Description

Feb. 13, 1951 J. A. DIAS ARRANGEMENT FOR AUTOMATICALLY STEERING A SHIP ON A PREDETERMINED COURSE 3 Sheets-Sheet 1 Filed Nov. 19, 1948 INVENTOR John A D1515 ATTURNE Feb. 13, 1951 J. A. DIAS ARRANGEMENT FOR AUTOMATICALLY STEERING A SHIP ON A PREDETERMINED COURSE 3 Sheets-Sheet 2 Filed Nov. 19, 1948 INVENTOR.

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ATTURNL' Feb. 13, 1951 J. A. DIAS 2,541,217

ARRANGEMENT FOR AUTOMATICALLY STEERING A SHIP ON A PREDETERMINED COURSE Filed Nov. 19, 1948 3 Sheets-Sheet 3 INVENTOR. d uhn A -I] '1 as Arr-DEWEY Patented Feb. 13, 1951 UNITED STATES PATENT OFFICE ARRANGEMENT FOR AUTOMATICALLY STEERING A SHIP ON A PREDETER- MINED COURSE John Alexander Dias, Bandra, Bombay, India 10. Claims. 1

This invention relates todevices for automatically steering a ship on a predetermined and preset course. This application is a continuationin-part of application Serial No. 637,709, filed December 28, 1945, now abandoned.

This invention has for its objects to provide means whereby such automatic steering is instantaneously effected should the ship deviate from the pre-set course.

The arrangement also provides for electrically steering the ship by hand operation when bringing the ship into or out of harbor or when the ship is in a congested trafiic lane.

The arrangement can also, with modification, be successfully applied to aircraft, particularly when such craft are to be flown long distances, and thereby relieve the navigator should it be necessary for him to leave his seat and attend to other matters.

According to the invention, there is provided an arrangement for automatically steering a ship on a predetermined and pre-set course in which an electric control is actuated should the ship deviate from the pre-set course. Briefly, the arrangement comprises means to stop the functioning of either of two separate photoelectric cells, independent of each other, by interrupting separate light beams to said cells and which are reflected by mirrors carried on the magnetic needles of two compasses. The photoelectric cells, when inactive one at a time, cause two separate relays to complete two separate circuits which, in turn, actuate a single field motor that is geared to the steering wheel shaft, whereby the steering apparatus is moved in the required direction to adjust such deviation of the pre-set course.

A feature of the invention is that the magnetic compass needles, preferably of the laminated type, are set to the desired direction by swivel stops mounted on a friction grip ring, marked with cardinal points of the compass, which may he slipped onto the periphery of the compass stand.

1n the preferred arrangement, the photoelectric cells, which are actuated by light beams reflected from mirrors carried by either of the magnetic needles, cause, when inactive, a series of relays to complete a selected electric circuit to a single field motor. The circuit from the port relays cause the motor to rotate in one direction and turn the rudder to starboard, while the circuit from the starboard relays cause the motor to retate in the opposite direction to turn the rudder to port.

A leading screw, turned by the motor simulill 2 taneously with the rudder, slides a block which operates two self-retracting limit switches, one at each end of the screw bed, which are movably mounted to permit adjusting the distance to be moved for operating the limit switches for cutting the electric motor circuit when the rudder reaches a pre-set angle, either port or starboard. The system is provided with alarms which selectively ring when the respective lamp circuits fail.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout the severalfigures and in which:

Fig. l is a diagrammatic layout of the preferredembodiment of the invention;

Fig. 2 is a cross sectional view taken axially of a compass in accordance with the present invention;

Fig. 3' is a plan view of the steering shaft control mechanism includin the adjustable limit switches;

Fig. 4 is a diagrammatic layout of a photoelectric cell circuit; and

Fig. 5 is a diagrammatic layout of a modified arrangement of the invention.

Referring now to the drawings, specifically to Fig. 1, the present invention contemplates the automatic adjustment of the shaft S, which may 7 be the steering wheel or the rudder shaft, to automatically maintain the craft on a pre-set course. According to a preferred embodiment, the invention comprises a pair of compasses I and I which are specially adapted to selectively control a reversible electric circuit for selectively energizing a reversible motor 2 which drives a worm 3 that is in mesh with a follower 4 on the shaft S.

The compasses I and I are identical in construction, as'best shown in Figs. 1 and 2. One of these compasses, compass I, will control deviations of the craft to port from the pre-set course and the other, compass I, will control deviations to starboard. Each of these compasses is adapted to be set to maintain the craft on a predetermined course within limited degrees on their respective port and starboard sides.

The compasses l and 1 respectively comprise a stand 5-5 which supports the compass post 6-6 on which the magnetic needle is journalled. In the present instance, a laminated needle structure is preferred. A pair of mirrors 33 and 9-41 are vertically mounted on the needle 1-1, back-to-back and on opposite sides of the pivotal axis of the needle '|-l". A friction ring |-|0 is movably mounted around the periphcry of the compass post 6-5 and has the cardinal points of the compass indicated thereon. An adjustable swivel stop tongue is mounted on the friction ring Ill-40', preferably at the north point on the ring, and is adapted to extend into the path of the magnetic needle 1-4.

A collar |2--|2 is mounted around the stand -5' and may be fixed in circumferential adjustment by a thumb screw |3-|3. The collar |2--| 2' supports three radially extending bracket arms |5|5, |6-|6' and |'|-|l which respectively support a lamp house |3-|8, a photoelectric cell l9--| 9 and a counter-weight 292| The lamp house |8-|9' and photocell |9|9 are positioned in a plane intersecting the mirrors 8-8 and 9-9 and are supported by their brackets |5--|5' and |6-|6 to be directed at right angles to each other. The compass post 6--E is provided with a plurality of pin holes 2|-2| arranged in a circle and adapted to selectively receive pins for restraining the needle during the course pre-setting operation.

The photocells l9 and I9 are respectively connected by conductors 22 and 22' with main lines 23 and 23 and by conductors 24 and 24 with electro- magnetic relays 25 and 25. The circuits for the photo-electric cells l9 and H! are best shown in Fig. 4. When the light beams from the lamps H5 or 8' strike the respective cell, the current generated by it passes throughresistances B and C, on to the potentiometer D and to conductors 24 or 24'.

The photocells l9 and I9 respectively energize the relays 25 and 25 when the cells are activated by the respective light beams reflected by the mirrors 8 and 8' or 9 and 9' from the lamps l8 and I8, and when the needles I and pivot to swing the mirrors 8 and 3' or 9 and 9 so that The relays 25 and 25' control the operation of 1.

the reversible circuits through the motor 2, and, as these relays are controlled by the photocells l9 and I9 which are operable by the lamps |8 and I8, it is imperative that the lamps be provided with alarm circuits. lamps l8 and I8 are respectively supplied from main line 23 by conductors 50 and 50 and manually operable switches 5| and 5|, and are respectively connected by conductors 52 and 52', through e1ectro- magnetic relays 53 and 53, to main line 23'.

The relays 53 and 53 respectively control switches 54 and 54 which are interposed in conductors 55 and 55' between signals or alarms 56 and 56 and the main line 23. The alarms 56 and 55' are respectively connected to main line 23 by conductors 5'! and 51 and manually operable switches 58 and 58'. Thus, when the lamps l8 and Hi are energized by closing manual switches 5| and 5|, the relays 53 and 53' are energized unless the lamp circuits are broken. When manual switches 58 and 53 are closed, the circuits are completed through the alarms 56 and 55 except for the relay switches 54 and. 54', which are opened when the relays Consequently, the v 53 and 53 are energized or automatically closed when the relays are de-energized by the breaking of the lamp circuits.

The photocell controlled relays and 25 respectively control switches 26 and 26 which are connected on one side by conductors 21 and 21 to one of the main lines 23 and on the other side to conductors 28 and 28' which extend to one pole 29a and 29a of manually operable double pole switches 29 and 29'. The other poles 29b and 29b of the switches 29 and 29' are connected by conductors 30 and 30' directly to the main line 23. The switches 29 and 29' are connected by conductors 3| and 3| with limit switches 32 and 32' which are connected by conductors 33 and 33' that extend through relays 34 and 34' to the other of the main lines 23.

The electro-magnetic relays 34 and 34' control, through levers 35 and 35, the operation of a reversing switch 36 which includes fixed contacts 36a and 36a and 36b and 35b, and movable contacts 360 and 350' which biase'l in opposite directions to intermediate, inactive or neutral position by springs 31 and 31'. The reversing switch 36 controls both the operation and the reversing of the field of the motor 2. The movable contact 360' is connected by conductor 38 with main line 23' and the other movable contact 360 is connected by conductor 39 to the motor 2 which, in turn, is connected by conductor 40 with main line 23.

The pairs of fixed contacts of the switch 36 are interconnected through the field 2a of the motor 2. The contact 36a is connected by conductor 4| with the field 2a which, in turn, is connected by conductor 42 with contact 36a. Contact 36b is connected by conductor 43 with contact 36a and field conductor 42, and contact 361) is connected by conductor 44 with contact 36a and conductor 4|.

Thus, if the switch 36 is closed by relav 34' with the or contacts, the motor 2 and field 2a is energized by a circuit from main line 23 through conductor 40, motor 2, conductor 39, movable contact 35c, fixed contact 36a, conductor 4|, field 2a, conductor 42, fixed contact 36a, movable contact 360, and conductor 38 to main line 23'.

Conversely, if the switch 36 is closed by relay 34 with the b contacts, a circuit is competed from main line 23 through conductor 40, motor 2, conductor 39, movable contact 350, fixed contact 36b, conductor 43, fixed contact 3611', conductor 42, field 2a, conductor 4|, fixed contact 36a, conductor 44, fixed contact 362 movable contact 350 and conductor 38 to main line 23'.

It will be seen that the circuit through the motor 2 and movable contacts 360 and 360 remains the same regardless of the direction through the field 2a. Furthermore, the field 2a is directly connected only to the fixed contacts 38a and 36a, but the direction of current flow therethrough may be reversed. Therefore, to clarify, the connection through the field lid, forward circuit F is shown in Fig. 1 by arrows extending from contact 36a, conductor 4|, field 2a, and conductor 42 to fixed contact 33a, and reverse circuit R is shown by arrows from contact 35b, conductors 43 and 42, field 2a and conductors ll and M to contact 357;.

When circuit is completed through motor 2, it drives worm 3 which rotates the follower i which then turns the shaft 5. If desired, a gear change system fill, controlled by a manually operable lever 6|, may be interposed between the. motor 2v and worm. 3.. ThErfOHOWeY. 4 may be connected to the shaft S. by a clutch 62. that is manually operable by a lever 63 to permit manual operation of the shaft S. When the clutch 62 is closed, the shaft S will be driven by the motor 2. when a motor. circuit is closed and as long as the circuit remains closed.

The operation of the motor is limited, however, by the limit switches 32 and 32 in the circuits controlling the reversing switch 36-. The. reversing switch 36 is normally maintained in neutral position by its springs 3'! and 31'. It is moved to close a motor circuit by the operation of one of the relays 34 or 34. The circuits of these relays, however, include the limit switches 32 and 32 which are subject to the driveof the motor 2.

As best shown in. Fig. 3, the limit switches 32 and 32' are carried by supports H1 and ill that are slidably mounted within a slot H in a. base plate 52. A leading screw or threaded rod 13 extends co-axially from the worm. 3 above the plate 12 and parallel with the slot H. A slide block i4 is threaded on the rod i3 with one end slidably anchored through a slot '15 in an upstanding fiange H on the plate "52 and the other end aligned between the limit switches 32 and 32. The plate 12 carries rudder angle indications along the slot H, the indications starting with zero centrally of the length of the slot.

The switch supports and iii may be adjustably positioned along the slot TI to the selected limit of rudder angulations. Then when the motor 2 is energized, it will drive the worm 3 and also turn the threaded rod l3 and thread. the blccl: l4 therealong it abuts and opens one of the limit switches 32 or 32, depending upon the direction of drive of the motor 2. The drive of the motor 2 and movement of the block 74 is such as to move the block toward the limit switch 32 or 32' that is in the circuit of the relay St or 34' which has been activated to close the reversing switch 3% and the motor circuit. Thus, when the block M opensthe respective limit switch 32 or 32, the respective relay 34 or 34' is deenergized and permits the riversing switch 38 to be neutralized by its springs 31 and 3'! and open the motor circuit.

A scriber Tl may be fixed to the protruding end of the sliding block 14 to scribe a line 18, representing the moverr-ent oi the rudder fluctuations, on a strip of moving paper 19 as it is slowly moved by winding on a roll 80. When taken at intervals from point to point on the meridian. and transferred to graphs, scribtd line it will show a difference, if any, when compared with the pro-calculated position of the. ship, and also facilitate correct positioning of rudder angle limit switches 32 and 52 to suit circumstances and conditions.

In the operation of the invention for automatic ing swivel stop tongue I! and marked cardinal.

points, until. the point 45 N. E; coincides with the fore line mark on the compass post 6.. Next,

he turns and secures the magnetic needle I flush with swivel tongue II by inserting a pin in one of the holes 2! on compass post 5, as shown in dotted line in Fig. l. The lamp !8 is then energized by'manually closing. the. switch 5!, thereby" energizing relay E3 and thus opening the circuit The manual switch 58, in circuit. with the bell or alarm 56;. is then closed. to: comto the bell 55.

plete the alarm: circuit.

The arm support ring 12 is then turned about the stand 5 until the light beam from the lamp. I8 is focussed by mirror 8 on photoelectric cell [9. This position of the ring or collar I2 is secured by tightening thumb screw l3. This position causes the cell 9 to act by its own current on relay 25 and open the switch 25%. The securingpin may then be removed from the hole to allow the compass needle '1 to revert to its free position, thusturning the mirror 3 and cutting off the: lightv beam. from cell i9. This action causes the cell 19 to remain inactive, the result being that relay 25 ceases to function and allows switch 26 to close.

The friction grip ring Hi, marked with cardinal points and bearing swivel tongue stop II, is

then turned about post 6 until the point 45 N. E. coincides with the fore line on compass post 6', allowing the magnetic needle 1 to turn with: it, being flush. with the stop ll, due to its magnetic force. The lamp 8" is then energized by manually closing switch 5|, thereby energizing relay 53 and causing it to break the circuit to the bell 55 by opening the switch '54. The manual. switch 58', in circuit with the bell 56, may then be closed.

The arm support. i2" is then adjusted on the stand 5 to focus the light beam from the lamp it through the mirror 3' onto the photoelectric .cell E9, in which. position the ring or collar i2 is locked by turning thumb screw 13. The photocell circuit being compktcd by the incidence of the light beam, it will act on relay 25' which in turn will open the switch 26. The final position oi: the parts of the compasses I and I, as pre-set to course and described above, are shown in Fig. 1.

limit switches 32 and 32 are pre-set along the slot 5! to cut oii the circuits of the relays 3d and 34 when the rudder is 50 starboard and port, respectively. The automatic steering mechanism is now completely set except for the manual switches 29 and 29 which may be closed with pol-es 29a and 2530: for automatic, or poles 23b and 23b for hand operation. As shown in Fig. 1, these switches are closed in automatic position; however, they are operated by hand with poles 29b and 2% to take the ship out of deck or harbor.

Upon moving switch 29 to terminal 2%, it completes a circuit directly from main line 23 through relay 3 t which, in turn, switches on fieldreversing switch 36 from neutral to terminals and completing circuit B (Fig. l), causing electric motor 2 to rotate in one direction and turn the rudder to starboard. On cutting off switch 28, field reversing switch 35 is pushed back to neutral by spring Bl. Similarly, on turning switch 29 to terminal 2%, it completes a circuit directly from. main line 23 through relay 3:3 which, in turn, switches field reversing switch 35 to the opposite set of terminals 36a and 35a, thus completing circuit F (Fig. 1), but motor 2 rotates in the opposite direction, turning'the rudder to port. Gn cutting on. switch 29', the field reversing switch 36 is pushed back to neutral:

position. by spring 37'.

This action of motor 2 is transmitted through multiple changed gear box so to worm 3 and worm wheel '4 to horizontal steering wheel shaft S which causes the steering engine to operate. As screw 73, fixed to worm 3, turns in eith r direction, it slides block i4 toward. one of the limit switches 32 or 32. to break the circuit through the respective relay 34 or 34'. Any

dete course before starting, the ship may 1 out of the docks or harbor by manually to starboard or port by closing with corresponding pols 255i) and 291). While the ship is going an the pre-set direction, as shown in e of the magnetic compass needles 1 '2" will be lush with its swivel. tongue step H H, account of its magnetic force. When out oi port, the switches 29 and 29 may be shif ed to automatic terminals zsa'and 2%, as shown i, whereupon the ship will immediately automatically in the direction pre-set by the swivel tongue stops H and H.

In the position shown Fig. 1, the light beam from lamp I3 is cut off from the photoelectric cell is, due to deviation of magnetic needle I, which ca: ,s the mirror 8, thus causing the cell "-9 rel-. to inactive and permitting the switch 25 to close. lhe closing of switch 26 l the circuit through pole 29a, switch 28,

'itch 32 and relay t l, to act on field re- ?ing switch 596 and complete circuit R with the rrent runn ng one direc the field coil Pic. snows starting position of mechanism at this stage.

The completion of circuit R actuates the motor 2 which, in turn, the rudder to swing to starboard through ltiple gear box 68, worm worm wheel l to steering wheel shaft S.

W action of motor 2 simultaneously turns leading screw '13 which slides block M to starboard, "1i: the rudder, if necessary, to reach the -set angle of 60 starboard, when limit switch opens up the circuit through the relay 35, thus the motor from rotating further. Upration of. relay 3%, reversing switch .Ld back by the spring 3'? to neutral Likewise when the ship swings to starboard from its course, magnetic needles l, carrying mirror 2, will deviate and cut off the light beam from lamp it on photoelectric cell It, causing cell and relay E5 to be inactive. Switch 26 is then automatically closed to complete the cir-- cult through relay which will cause field re' 32"; to connect with the opposite r. of termi al The current will now flow t 1e field coil 2:; but in opposite dir ction, circ t F, thus reversing he motor 2 "o cause swinging of the rudder to port. Simul- )Etl'lCDllSljy" leading screw 23 will reverse the slide c to port for acting on retracting switch 1 o up the circuit through relay 34', should the rudder reach the pre-set angle 35 voyages on course, rudder angles wheel shaft speed gears may be re cit conditions. While turning, the magand l be permitted to swerve ting swivel tongue stops H and H. .Olfl 9 and ii will then reflect the light beams cells and lil. Direction pres. of course are then read from cardinal p to coinciding with the aft line marks on so sass posts fl and ii.

As a further test that the apparatus is op tive and fully automatic, open switches 5| and around by l.

8 5| to switch oil lamps l8 and I8. Steer the ship to any position and reset rudder angles, if necessary, to suit conditions caused by extent of deviation for return to pre-set course. With one of the magnetic needles either I or I lying flush with its respective swivel tongue stop II or II, switch on the lamps l8 and IS. The ship will immediately steer utomatically towards the course and maintain the pre-set, predetermined and desired course.

Several pairs of compass sets may be connected to the same automatic steering mechanism, especially at stem and stern, to secure true and more accurate alignment of the ship with its predetermined and pro-set course. This arrangement is shown in Fig. 5, the components being duplicated throughout the several pairs of compasses.

The worm wheel 4, or its section, can be fixed directly on the rudder post, instead of the steering wheel shaft, and engaged by a clutch, leaving automatic hand control switches for operation on the navigation deck.

All relays are, preferably, magnetically sealed to shield the compass magnets.

The electric circuits illustrated in the drawings are for direct on rent single field motors but suitable modification can be made for three- ;hase alternating current motors without dep rting from the scope of the invention.

Adjustments to suit weather and sea conditions achieved. by gear changes and settings of ii; switches 32 and 32 to stabilize either port or starboard rudder angle position individually.

Although certain specific embodiments of the invention have been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be r stricted except in so far as is necessitated by the prior art and by the spirit of the appended claims.

What I claim is:

1. Apparatus for steering a craft on a pre selected course, which apparatus comprises a reversible electric motor operatively connected to a shaft of the steering mechanism of a craft, an electric circuit for selectively energizing said motor, two photoelectric cells subject to activation by light beams for selectively controlling said motor circuit, a pair of compasses, means for supporting one of said cells in selected position relative to each of said compasses, and reflectors carried on the magnets of said for respectively reflecting light beams toward said photoelectric cells when magnets in certain angular positions.

2. Apparatus for steering a craft on electric circuit for selectively energizing said motor, two photoelectric cells subject to activa-- tion by light beams for selectively decontrolling said motor circuit, a pair of compasses means for supporting one of said cells in selected position elative to each of said compasses, and reflectors carried on the magnets of said compasses for respectively reflecting light beams toward said photoelectric cells v ien magnets are in proper angular positions while the craft is on the ire-selected course.

3. Control apparatus which comprises a control shaft to be turned, a reversible electric motor operatively connected to said shaft, an electric circuit for selectively energizing said motor to turn said shaft, two photoelectric cells subject to activation by light beams for selectively controlling said motor circuit, a pair of compasses, means for supporting one of said cells in selected position relative to each of said compasses, reflectors carried on the magnets of said compasses for respectively reflecting light beams toward said photoelectric cells when said magnets are in certain angular positions, a pair of limit switches in said circuit for de-energizing said motor, and means operated by said motor simultaneously with the driving of said shaft for operating one of said limit switches to deenergize said motor after a selected time.

4. Control apparatus as defined in claim 3 wherein said limit switches are spaced in opposed relation and said motor operated means includes a member movable in aligmnent with and'between said switches.

5.v Control apparatus as defined in claim 4 wherein said limit switches are adjustably positioned to enable variable spacing, and said motor operated means includes a threaded rod driven by said motor and supporting said movable member.

6. Control apparatus as defined in claim 3 wherein said motor is operatively connected to said shaft by a manually operable clutch.

7. Control apparatus comprising a circuit to be controlled, means for energizing said circuit, two photoelectric cells subject to activation by light beams for selectively controlling said means, a pair of compasses, means for supporting one of said cells in selected position relative to each of said compasses, and reflectors carried on the magnets of said compasses for respectively refleeting light beams toward said photoelectric cells when said magnets are in certain angular positions.

8. Control apparatus comprising alternate circuits to be controlled, means for energizing each 10 of said circuits, a photoelectric cell for controlling each of said means, two compasses each including a magnet, means for supporting one of said cells in selected position relative to each of said comabutting said stops.

9. Control apparatus as defined in claim 8 wherein said stops are pivotally mounted on rings which have the cardinal points marked thereon and which are respectively movable about the peripheries of said compasses.

10. Control apparatus comprising alternate circuits to be controlled, means for energizing each of said circuits, relays for respectively controlling each of said means to deenergize the circuits when the relays are energized, two photoelectric cells for energizing said relays when said cells are activated by the impingement of light beams, two compasses each including a magnet, means for supporting one of said cells in selected positions relative to each of said compasses, a stop adjustably positioned in the path of the magnet of each compass to limit the movement of its magnet in one direction, the stops being on opposite sides of their respective magnets, and reflectors carried on the magnets for respectively reflecting light beams toward the photo-electric cell associated therewith when abutting said stops.

JOHN ALEXANDER DIAS.

No references cited.

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