US2987027A - Propeller thrust stabilizer control - Google Patents

Description

June 6, 1961 A. w. WANZER PROPELLER THRUST STABILIZER CONTROL 3 Sheets-Sheet 1 Filed Sept. 16, 1957 June 6, 1961 A. w. WANZER PROPELLER THRUST STABILIZER CONTROL 3 Sheets-Sheet 2 Filed Sept. 16, 1957 LEV June 6, 1961 w w z 2,987,027

PROPELLER THRUST STABILIZER CONTROL Filed Sept. 16, 1957 3 Sheets-Sheet 3 United States Patent 2,987,027 PROPELLER THRUST STABILIZER CONTROL Arthur W. Wanzer, 19 Tower Road, Hingham, Mass. Filed Sept. 16, 1957, Ser. No. 684,317 5 Claims. (Cl. 114-422) The present invention relates to an improved apparatus for propelling and stabilizing waterborne craft.

More specifically the present invention relates to the use of outboard propulsion units of the general type comprising a downwardly projecting outboard housing and a rotary propeller unit having its axis and direction of thrust transverse to the housing, and swiveled with relation to the craft to vary horizontally the direction of thrust, to provide a more economical and eflicient control both for the propulsion and maneuvering and for the stabilizing of the craft against tipping in any specified direction.

Outboard propulsion units of this general description have been found most efficient for the maneuvering of waterborne craft such as barges, scows and the like.

It is a principal object of the invention to provide a novel and improved control apparatus which is well adapted for individual manual control of a plurality of such propulsion units, and alternatively for the simultaneous swiveling of said units as a group under the direction of a direction tip sensor unit to compensate for and offset any tendency of the craft to tip in any direction.

It is a further object of the invention to provide an efiicient group control of two or more such propulsion units located toward opposite ends of a conventional propeller driven ship, which is well adapted to permit individual control of said units for maneuvering the ship in restricted waters, and which is alternatively operable for swiveling said units simultaneously in a most eflicient manner to reduce roll.

It is a further object of the invention to provide a novel stabilizing control adapted to eliminate any tipping movement which might otherwise be imparted to a floating oil rig or similar device which is waterborne as, for example, on a conventional barge, and from which a drill or connecting pipe is extended downwardly beneath the ocean floor.

With these and other objects in view as may hereinafter appear a feature of the invention consists in the provision of fore and aft outboard propulsion units which are attached to or may be projected downwardly from the bottom of a ship and which are adapted for individual manual swiveling control for maneuvering the ship, and which in accordance with the invention are further adapted to be controlled by a stabilizing sensor device as a unit to minimize or eliminate ship roll while the ship is at sea. The stabilizing control referred to is constructed and arranged to effect a simultaneous swiveling movement of the two propulsion units in the same direction and to the same extent to offset and to damp out such rolling action of the ships hull. lln the embodiment of the invention illustrated the stabilizing sensor is arranged to act through an effort thrust control to impart a simultaneous swiveling movement in the same direction to the two outboard units, these movements being proportioned to offset and damp out any tendency of the bull to roll.

Another feature of the invention consists in the provision in an alternative embodiment of the invention of a floating oil rig comprising the rig, a scow on which the rig is mounted, and a plurality of outboard propulsion units mounted as, for example, in the instance shown toward opposite ends of the scow. In the embodiment shown a propeller thrust stabilizing control is employed which consists in the provision of a direction roll sensor device sensitive to the direction of roll or pitch of the ice craft around 360 of horizon and an elfort thrust control which in response to a signal from the roll sensor device acts to impart simultaneous rotational movement to the two propulsion units to a position which will directly offset the roll tendency referred to.

In the embodiment of the invention shown in FIG. 3 the propulsion units are arranged to cooperate with anchor lines which are attached to the oil rig tower at a level substantially above the deck level of the barge, thereby very substantially increasing the leverage exerted by the propulsion units referred to to avoid any tipping displacement of the barge.

A further feature of the invention consists in the provision of a stabilizing control mechanism which is well adapted for simultaneous swiveling control of the outboard propulsion units and which is further adapted to control the power output of said units in accordance with the variations in velocity and acceleration of any rolling action of the craft.

Wit-h the above and other objects in view as may hereinafter appear, the several features of the invention consist also in the devices, combinations and arrangements of parts hereinafter described and claimed which, together with the advantages to be obtained thereby, will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawings, in which,

FIG. 1 is a side view of a ship having mounted thereon in addition to the usual driving propeller two fore and aft propulsion units which are arranged to be projected downwardly through the bottom of the ship for the maneuvering and for stabilizing the same in accordance with the invention;

FIG. 2 is a sectional view taken on a line 2-2 of FIG. 1, illustrating particularly the position of the aft maneuvering and stabilizing propulsion unit;

FIG. 3 is a view in side elevation of a barge on which is mounted an oil rig together with anchoring cables and two propulsion units arranged in accordance with the present invention to prevent tipping of the barge in any direction;

FIGS. 4, 5 and 6 are enlarged detail views in section of one of the propulsion units illustrated in FIGS. 1 and 2, of which FIG. 4 is a sectional view in side elevation showing the propulsion unit in its raised inoperative position within the hull of the ship;

FIG. 5 is a view similar to FIG. 4 but showing the propulsion unit in its lowered operative position;

FIG. 6 is a sectional view taken on a line 6-6 of FIG. 4;

FIG. 7 is a schematic view of a propulsion thrust stabilizer control particularly adapted for use with the oil rig illustrated in FIG. 3 in which tip or list correction is required about 360 of horizon; and

FIG. 8 is a schematic view illustrating a propulsion thrust maneuvering and stabilizing control particularly adapted for use in a ship such as that shown particularly in FIGS. 1 and 2.

In the drawings two specific embodiments of the invention are shown, one being a maneuvering and stabilizing propul-sion control unit particularly adapted for use with a ship, a shown in FIGS. 1, 2 and 8, and the other being a stabilizing propulsion unit control particularly adapted for use with a floating oil rig as shown in FIGS. 3 and 7.

FIGS. 1 and 2 illustrate the hull '20 of a ship in which there is mounted offset from the keel adjacent the forward end thereof an outboard propulsion unit 22, and adjacent the rear end of the ship a second propulsion unit generally designated at 24. Inasmuch as the propulsion units are identical, only the propulsion unit 24 as shown will be described in detail in connection with FIGS. 4, 5 and 6.

The propulsion unit 24 consists of a propeller 26 which is mounted on a horizontally disposed propeller shaft 28 within a downwardly extending outboard housing 30 which is mounted to swivel about a vertical axis to control the direction of thrust of the propeller 26.

As best shown in FIG. 4 the propeller shaft 28 is connected by beveled gears 32, 34 with a vertically disposed drive shaft 36 which extends vertically upwardly along the axis of rotation of the housing 30. The outboard housing 30 and propeller 26 of the propulsion unit are suspended from a cylindrical drum-like container 38 which is vertically adjustable within a cylindrical well 40 built into the ships bottom. The container 38 referred to is closed at its lower end by means of a disc-shaped sealing and supporting element 42. The outboard housing 30 is bolted to a vertically disposed rotatable tube 44 which extends upwardly through the sealing disc 42 and through a cylindrical supporting disc 46 which is tightly fitted against and secured to the inner face of the drum-like container 38.

As best shown in FIG. 4 of the drawing, the drive shaft 36 extends upwardly through the outboard housing 24 and sleeve housing 44 and is connected by means of a coupling 48 to the armature shaft 50 of a vertically disposed propulsion driving motor 52.

The sealing disc 42 is arranged when the unit is in the downward operative position of FIG. to engage a cooperating sealing ring 54 formed in the open end of the well 40 to prevent water from entering the hull. When the propulsion unit is raised, the sealing ring 42 is withdrawn upwardly into the well 40 and a sealing disc 56 secured to the botto'm of the outboard housing 24 moves into the sealing position with relation to sealing ring 54 as best shown in FIG. 4.

The propulsion unit assembly is locked securely in each of its operative and inoperative positions by engagement of spring plungers 60 with a grooved peripheral surface 96 formed in the sealing disk 42 and alternatively with an annular groove 68 formed in the side wall of the cylindrical container 38. In the upwardly withdrawn position of the units shown in FIG. 4 the locking plungers 60 are engaged with the groove 69 formed in the peripheral surface of disc 42. When the propulsion unit is lowered to its operative position shown in FIG. 5 the pins 60 engage in the annular recess 68 formed in the wall of the cylindrical container 38. The propulsion unit is raised and lowered by any convenient form of apparatus, as, for example, the cable 72 suspended from a pulley 73 forming part of power operated lifting equipment not specifically shown. The cable 72 is provided at its lower end with a hook 74 which engages an eyebolt 76 formed in a cover plate 77 forming part of the cylindrical drum-like container 38.

The mechanism illustrated for rotating the tube 44 and outboard housing 30 comprises a worm gear 80 mounted integrally with the tube 44 and a worm gear 82 which is connected to be driven from an electric steering motor 86 through a reduction gear unit generally indicated at 87.

The manner in which the outboard propulsion units 22 and 24 maybe controlled for maneuvering and alternatively for the stabilizing control of the ship 20 in accordance with the invention will be briefly described in connection with the schematic drawing of FIG. 8 as follows:

It will be assumed that both of the units have been moved downwardly to their lowered operative positions as particularly shown in FIG. 5 and that both driving motors 52 are in operation to drive the respective propellers 26.

The schematic drawing discloses two manually operable steering wheels 90 and 92 which may, for example, be mounted on the bridge of the ship. Assuming that each of the motors is set up for individual manual control, the rotation of wheel 90 will act through a forward steering transmitter indicated by the box 94 to transmit an electrical signal through electrical wiring 95 to a motor control indicated by a box 96 and to a forward steering control indicated by a box 97, which will cause the corresponding steering electric motor 86 to operate until the outboard housing 24 and propeller 26 have been brought to the steering position indicated by the po'sition of the wheel 90. Similarly any rotation of the after steering wheel 92 will act through the after steering transmitter indicated generally by the box 100, through suitable electrical connections including a line 101, a motor control indicated by a box 102 and the after steering motor indicated generally by a box 103 to position the outboard housing and propeller of the after propulsion unit 24 in the position demanded by the movement of the after steering wheel 92. Separate controls, not here shown since these parts do not form specifically a part of the present invention, would no'rmally be provided for steering and for stopping the propeller driving motors, and for effecting the automatic lowering and raising of the outboard units to and from their lowered operative position.

In accordance with the present invention, it is proposed to cause the two propeller units 22 and 24 to operate automatically and simultaneously as a unit to effect a lateral thrust which is gauged in accordance with, and which will be effective to substantially overcome and damp out any tendency of the ship to roll during its forward progress at sea.

Referring to the schematic FIG. 8, a positional transmitter is provided, indicated in the drawing as a block 104, which is controlled by means of a pendulum 106 and is instantly responsive to any tendency of the ship to roll. The positional transmitter 104 is rendered operative to simultaneously control the two outboard units by means of a double pole double throw switch 108, 110, which is shifted from the solid to the dotted line position shown, thus disconnecting the motors from manual operation by the steering wheels 90, 92 and connecting these motors and their controls directly with the positional transmitter 104. Identical impulses will now be transmitted from the transmitter 104 through lines 112, 95 to the forward steering motor control 96 and through lines 114, 101 to the after steering motor control 102 and motor indicated by box 103. The net change in the direction of thrust imparted by each of the outboard maneuvering and stabilizing units by the operation of the steering motors indicated by the boxes 97 and 103 in FIG. 8 and by the reference character 86 in FIG. 6 under the control of the positional transmitter 104 may be proportioned to the extent of each tipping movement of the ship which will cause the pendulum 106 to move a greater or lesser amount from its intermediate neutral position. Electrical motor controls which will sense and are responsive to the extent of movement of a pendulum are well known and may be employed to drive the steering motors 86 for controlled periods to swing the outboard housings and propellers by an amount which is just sufficient to offset the tendency of the ship to roll.

Referring more specifically to FIG. 3 of the drawings illustrating another embodiment of the invention, a barge is shown on which is mounted an oil well rig consisting of a square tower 122, a centrally located drill header shaft 124 and four anchor lines 126, 128, and 132 disposed about the four sides of the barge and fastened to the tower 122 at a level chosen substantially above the deck level of the barge 120 thus providing a substantially fixed point of anchorage above the barge. The barge 120 has mounted on opposite sides thereof two propulsion units 134, 136 similar to those previously described.

The two units are carried on the deck of the barge and are provided respectively with downwardly extending housings 138, 140, and with rotary propeller units in the form of propellers 142, 144 and propeller shafts 146, 148

. having their axes and direction of thrust transverse to the housing.

Inasmuch as the individual propulsion units comprise the same basic elements as those previously described and particularly illustrated in FIGS. 4, 5 and 6 including the outboard housing and propeller unit mounted to swivel about a vertical axis to control the direction of thrust of the propeller, a propeller driving motor, and a steering motor, it is believed unnecessary to illustrate these outboard units in further detail.

Each of the propulsion units 134 and 136 is provided with an outboard housing which is readily adapted to be swiveled on its vertical axis through 360 of rotation, a propeller and a driving motor therefor, and an electric steering motor suitable for turning the outboard housing and propeller therewith to any desired position.

The two outboard units shown in FIG. 3 of the drawings are adapted to be controlled as a unit by means of a stabilizer control which includes a direction of roll sensor and together with an effort direction control device which operates to rotate the outboard housings and propellers of the two units simultaneously and in unison to a position which will exactly :oppose any detected tendency of the barge to tip in any direction.

In the illustrated form of the device there is also provided a roll velocity sensor and roll acceleration sensor which are responsive respectively to the velocity and acceleration of roll, and which are arranged to operate through an ordered computor servo device to control the rate of drive of each of the two propellers.

Referring more specifically to the schematic illustration of the propeller thrust stabilizer control of FIG. 7, the barge 120 is indicated by a block which is connected by cross-hatched double lines with other elements of the schmatic drawing which are assumed to be located within the barge. These elements include the propulsion unit 134 above referred to which is designated as being part of the barge by the cross-hatched double line 141 and is marked as the number 1 unit, and the second propulsion unit 136 indicated as a box marked as the number 2 unit and similarly connected with the barge 120 by a cross-hatched double line 143. In the illustrated form of the device there is also provided a roll velocity sensor indicated by box 145 which is connected by means of a cross-hatched double line 147 with the barge 120, a roll acceleration sensor indicated by a box 149 and connected by crosshatched double line 150 with the barge 120, and a direction of roll sensor 152 which is connected with the barge 120 by a cross-hatched double line 154.

It will be noted that the direction of roll sensor is connected by a line of electrical wiring 156 with an etfort direction control indicated as a box 158, which is in turn connected through a suitable line of electrical wiring 16%) with the No. l outboard propulsion unit 1'34 and is connected by a similar line of electrical wiring 162 with the No. 2 outboard propulsion unit 136. It will be noted that the direction of roll sensor is connected by means of lines of electrical wiring 1:66 and 168 and manual switches 174 and 176 with two direction limit stops designated respectively by boxes 170 and 172. The manual switches 174 and 176 are shown for the purposes of this description in their open inoperative position.

The direction of roll sensor, which may be more specifically described as a device responsive to the tipping movement of the barge in any direction from the horizontal, may in response to a tipping movement of the barge send a signal through wire 156 to the effort direction control 158 which is thus rendered operative to drive the steering motors 86 simultaneously and in the same direction until the outboard housings and propellers have been rotated to the desired compass position so that the thrust of the two propellers will be effective to oppose this tipping movement of the barge.

In addition to the correction of the angular position of thrust of the outboard housings and propellers, provision is also made for adjusting the power output of the two motors to correspond with the strength of the urge of the tipping motion to which the barge is subjected. To this end the roll velocity sensor and roll acceleration sensor 149 are provided which are responsive respectively to the velocity and acceleration of the tip or roll of the vessel. 'Each of these sensors sends out an electrical signal, said signals, being transmitted respectively by the connections 178 and 179 to an ordered computor servo designated by box 180.

The ordered computor servo device is connected by lines of electrical wiring 184 and 186 with throttle devices not specifically shown for the respective propulion units 134, 136. These lines 184, 186 are utilized to inform the ordered computor servo device of the actual correction of each of the two throttle devices. An ordered correction is then made by the ordered computor servo device through lines of wiring 188 and 190 to two effort controls designated by boxes 192 and 194, which in turn act through lines of wiring 196 and 198 to adjust the position of the respective throttle devices in the two propulsion units. This correction in the position of the respective throttles may be regarded as a correction of error computed by the ordered computor servo device in response to the signals imparted by the respective roll velocity sensor and roll acceleration sensor.

The invention having been described, what is claimed is:

1. An apparatus for maneuvering and stabilizing a ship comprising a pair of outboard propulsion units mounted in forward and aft positions on said ship, each said propulsion unit comprising an outboard housing projecting downwardly from said vessel and swiveled to turn on a vertical axis with relation thereto, and a rotary propulsion unit mounted from said housing having its axis and direction of thrust transverse to said downwardly projecting outboard housing, individual steering motors connected with the outboard housing for swiveling said housings to control the direction of thrust, individual manual steering controls and connections for said steering controls to the steering motors of the respective propulsion units to control the direction of thrust, an alternatively available automatic stabilizing control for said ship comprising a roll tip sensor unit constructed and arranged to emit signals in response to a rolling movement of said ship from an intermediate neutral position in either direction, and an effort direction control unit constructed and arranged to be responsive to said signals to effect a simultaneous operation of said steering motors to effect a parallel swiveling movement of said propulsion units and direction of thrust in any direction and to a degree proportioned to the extent of the rolling movement of the ship and in a direction opposed to the direction of tip as indicated by movement of said direction tip sensor.

2. An apparatus for stabilizing a waterborne oil rig comprising a barge, a tower erected on the barge, a drill header shaft extending beneath the ocean floor, and a plurality of anchor lines connected between the ocean floor and said tower substantially above the level of the barge providing a substantially fixed point of anchorage above the barge, having in combination, an outboard housing projecting downwardly from said barge swiveled to turn on a vertical axis with relation to the barge, a rotary propulsion element mounted from said outboard housing having its axis and direction of thrust transverse to said vertical axis, a motor connected to drive the propulsion element, a steering motor connected with said outboard housing operable to rotate the outboard housing and propulsion element mounted thereon about 360", a barge tip sensor unit responsive to tipping movement of the barge in any direction, and an effort direction control unit actuated by said sensor unit to drive said steering motor to effect a swiveling movement of said outboard housingand associated propulsion element to a direction of thrust position directly opposed to the diaeezoav rection of tip as indicated by said direction of tip sensor.

3. An apparatus for stabilizing a waterborne oil rig comprising a barge, a tower erected on the barge, and a drill header shaft extending beneath the ocean floor, and a plurality of anchor lines connected between the ocean floor and said tower substantially above the level of the barge, having in combination, a plurality of propulsion units mounted at different locations, each said propulsion units comprising an outboard housing projecting from said barge swiveled to turn on a vertical axis with relation thereto, a rotary propulsion element mounted from said outboard housing having its axis and direction of thrust transverse to said vertical axis, a motor connected to drive the propulsion element, and a steering motor connected with said outboard housing operable to rotate the outboard housing and propulsion unit mounted thereon about 360, and an automatic stabilizing control for said oil rig comprising a direction tip sensor unit constructed and arranged to emit signals in response to tipping movement of the barge indicating the direction of said tip, and an effort direction control unit actuated by the signals from said direction tip sensor unit to drive said steering motors to efieet a simultaneous swiveling movement of each of said outboard housings and associated propulsion elements in a direction opposed to the direction of tip as indicated by said direction tip sensor.

4. An apparatus for stabilizing a waterborne oil rig according to claim 3 in which there is further provided a roll velocity sensor unit and a roll acceleration sensor unit responsive to tipping movement of said barge, an ordered computor servo electrically connected with said roll velocity sensor and said roll acceleration sensor unit, effort control units connected with each of said propulsion units to determine the amount of thrust produced thereby, and electrical connections from said ordered computor servo for simultaneously adjusting each of said effort control units.

5. An apparatus for stabilizing a water borne oil rig according to claim 2 in which there is further provided means for adjusting the power output of said propulsion unit drive motor to correspond with the strength of the urge of the tipping motion to which the barge is subjected, which comprises roll velocity and acceleration sensing means emitting a signal responsive to tipping movements of the barge, an ordered computer servo unit operatively connected with and responsive to the signal from said roll velocity and acceleration sensing means, and means connecting said ordered computer servo unit with said propulsion unit to control the power output of said propulsion unit in accordance with said signal.

References Cited in the file of this patent UNITED STATES PATENTS 2,130,929 Rocard Sept. 20, 1938 2,213,611 Ronning Sept. 3, 1940 2,399,656 Armstrong May 7, 1946 2,809,603 Bell Oct. 15, 1957

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