US2155892A

US2155892A - Stabilizing device

Info

Publication number: US2155892A
Application number: US184492A
Authority: US
Inventors: Steinen Carl Von Den
Original assignee: Askania Werke AG
Current assignee: Askania Werke AG
Priority date: 1937-01-08
Filing date: 1938-01-11
Publication date: 1939-04-25
Anticipated expiration: 1956-04-25

Description

April 25, 1939. Q VON DEN STEINEN 2,155,892

STABILIZ'ING DEVICE Filed Jar 1. 11. 19 38 2 Sheets-Sheet l 08 PITCH DIRECTION April 1939. c. VON DEN STEINEN 2,155,392

STABILIZING DEVICE Filed Jan. 11, 1938 2 Sheets-Sheet 2 III-[:ICJCIIIIEIUEIEJEJEIICI Patented Apr. 25, 1939 UNITED STATES PATENT OFFICE many, assignor to Askania-Werke A. G., a c' poration of Germany Application January 11, 1938, Serial No. 184,492

' In Germany January 8, 1937 I Claims.

smThis invention relates to stabilizing devices for It is an object of this invention to provide a device for exerting stabilizing moments on a ship 5 about its longitudinal axis for the purpose of effecting an anti-rolling stabilization of the ship.-

It is a further object to provide a device 'capable of simultaneously propelling and stabilizing a ship.

According to this invention I provide in a ship, as hereinafter set forth in detail, a' Schneider propeller adjustable in response to lateral inclinations and capable of exertingmoments about the longitudinal axis of the ship. The Schneider propeller as an element is well-known in the art and comprises a rotatable support from which a plurality of blades project parallel to the axis of rotation of the support, the blades being adjustable relatively thereto. Depending upon the ad 90 iustment oi the blades relatively to the support the blades exert a propelling force in any desired direction normal to the axis of rotation. According to this invention a Schneider propeller is 'em-' ployed normally to propel the ship and to exert stabilizing moments on the same upon deviations of the ship from its normal position.

Further aims, objects, and advantages of this invention will appear from a consideration of the description which follows with the accompanylng drawings showing for purely illustrative pur poses an embodiment of this invention. It is to be understood, however, thatthe description is not to be taken in a limiting sense, the scope of this invention being defined in the appended claims.

Referring to the drawings: Fig. 1 is a plan view, partly in section, of a Schneider propeller, the propeller blades being shown in a neutral inactive position. Fig. 2 shows the propeller of Fig. 1 adjusted for propelling action.

Fig. 3 is a diagrammatic illustration of a ship equipped with a stabilizing Schneider propeller. Figs. 4 to 6 are diagrams illustrating different adjustments of the propeller.

Fig. .7 is a diagram illustrating apparatus for adjusting the propeller blades.

The construction and operation of the Schneider propeller are well-known in the art and described for example in my copending application Ser. 184,492 filed January ll, 1938. It may therefore sufiice to show and .describe in connection with this invention only the most essen 1 elements of .the propeller.

In support It! rotatable about an axis 2 and ll driven by a "suitable source (not shown) a plurality of propeller blades I! to "5 are mounted with their shafts I! to 22 extend parallel to the axis of rotation. The propeller blades are of a cross section similar to that of the wing of an air-plane to offer a minimum resistance to the 5 water. To the shafts I! to 22 webs 23 to 28 are securedhaving crank pins-'29 to 34 to which connecting rods 35 to "are connected. The other ends of the connecting rods are pivotally linked to levers 4| to 46, the levers being pivotally con- 10 nected to a disk 41 at 48 to 53, respectively. The levers 4| to 46 are guided in guiding blocks 54 to 59 pivotally connected at 60 to 65, respectively, to a. disk 66 secured to or integral with the support l0. 15

'Assuming that the disk 41 be adjusted to be concentric to the disk 66 and the support I6 it follows that the blades will upon rotation of the support It travel ,in a circle indicated in a dashdot line Without exerting on the water a force, 20 other than the resistance offered to the curved front of the blades.

Turning now to Fig. 2, the disk 41 is shown in an excentric position relatively to the support l0 and the disk 66. Assuming now that the support 2| II] is rotated about the axis 2 in the direction of the arrow 3, while the center 4 of the disk 41 is maintained fixed, the propeller blades will perform an oscillating movement about their respective shafts and a further movement about the 30 axis 2 with their surfaces inclined relatively to the direction of travel. Accordingly forces will be exerted on the water as will become still clearer from a consideration of the diagrammatic Figures 4 to 6. .35

In Figs. 4 to 6 the center of the support is indicated at 2, while the center of the disk 41 is indicated at 4. The direction of movement of the'blades is again indicated by arrows 3. An axis 5-5 may be assumed to be parallel tothe longitudinal axis of the ship, while an axis 66 is normal thereto. v 4

A displacement of the center 4 in the direction of the axis 66 will result in a movement of the 5 blades which is shown in Fig. 4.

Four diiferent positions o1 the blades are indicated at A to D. The lever mechanism shown in Figs. 1 and 2 will cause an oscillating inovement of the blades as follows: A blade which is aligned 50 withthe direction of travel at A will be oscillated in clockwise direction to become inclined as shown at B reacting on the water. Thereafter the levers impart a counter-clockwise oscillation to the blade; At C the blade is again aligned with the direction of travel and at D inclined to react on the water. I

The oscillating movement of the blades together with the rotary movement in the direction 3 results in a reaction of the blades on the surrounding water indicated by the arrows I. The direction of the resultant force is approximately normal to a line connecting the centers 2 and 4.

A different adjustment of the blades is shown in Fig. 5 caused by a displacement of the center of the disk 46 into a position 4'. Four different positions of the blades are again indicated at A to D. It clearly appears from the position of the blades that a force will be exerted on the water in the direction of the arrows 'I' inclined to the direction of the axis 6-6.

A still different adjustment of the Schneider propeller is shown in Fig. 6. In this example the center 4 is displaced in the direction of the axis 5-5 resulting in a movement of the blades which is again shown in four phases A" to D". The resultant force on the water is indicated by the arrows 'I" directed parallel with the axis 6-6 and normal to the longitudinal axis 5-5 of the ship. a

For exerting stabilizing moments on a ship the Schneider propeller is mounted on the body of the ship in such manner that the propeller blades protrude from the ships bottom.

In Fig. 3 a Schneider propeller having a'casing 51 with an electric motor enclosed therein for driving the propeller is mounted without a water-tight compartment '80 of the ship. A spindle 69 and a nut I forming part of a worm gear II drivenby a motor I2 permits the casing 61 to be lowered into the operative position shown in the drawings in which the propeller blades protrude below the bottom of the ship. In shallow water, wherev damage is likely to occur to the propeller blades, the casing 61 may be raised into the compartment, whereby the blades are pro tected.

Inasmuch as the blades are arranged below the center of gravity of the ship through which also the longitudinal axis -5 is assumed to pass it is easily understood that the propeller blades are capable of exerting a reacting moment on the ship about the axis 5-5, when adjusted in response to lateral inclinations of the ship.

Assuming, for example,.that the blades be adjusted as shown in Fig. 6 in which the propeller acts on the water in the direction normal to the axis 5-5 it appears that a maximum moment will be exerted on the ship.

when, in turn, the propeller is so adjusted as to act parallel to the axis .5-5 it appears that it will assist in a propulsion of the ship. The propeller accordingly fulfills a double purpose, first the purpose of stabilizing'the ship and second the purpose of propelling it. For propelling the ship the Schneider propeller may be assisted by the usual propeller indicated at," in Fig. 3, it being understood that the propeller I3 may also be dispensed with and the propulsion of the ship be effected exclusively by the Schneider propeller 01. The course of the ship is controlled by the usual rudder I4.

The most effective stabilizing action of the Schneider propeller is obtained when the propeller is positioned below the center of gravity of the "ship, but vertically spaced relatively thereto. I have found by experiments that the stabilizin action is not essentiallyjafi'ected when the propeller is positioned spaced not more than one quarter of the ship's length from the center of gravity in a horizontal direction. When the horizontal distance of the propellerjs. greater than one quarter'of the ships length," the course of the ship will be affected by the propeller and the direction of the ship be changed rather than its stability.

A suitable form of apparatus for controlling and adjusting the Schneider propeller in response to lateral inclinations of the ship is shown in Fig. 7. A pendulum .15 is pivoted at I5 for oscillations transversely to the direction of travel of the ship. The pendulum may be of the short period type assuming the direction of the apparent vertical or of the long period type assuming the direction of the true vertical, depending upon whether it is desired to stabilize the ship with respect to the apparent or the true vertical.

The pendulum in the illustrated example is combined with a follow-up device including a sector shaped follower 11 provided with a toothed edge 'I0meshing with a worm l9 rotatable by a reversible motor 80. The motor is supplied with current from a battery 8i and controlled by contacts 82 on the pendulum and 83, 04 carried by the follower. The contacts 03 and 84 are connectedwith the motor through leads 85 and 86, while a lead 81 connects the battery with the pendulum.

When the pendulum becomes displaced relatively to the follower, one of the pair of

contacts

02, 83 or 82 84 will be closed causing the motor to turn the worm I9 in such direction that the follower 'II follows the movement of the pendulum. Thus the position of the follower becomes a measure of the lateral inclinations of the ship.

The movements of the follower are transmitted to actuate a relay, in the illustrated example shown as being an Askania" jet-pipe relay ineluding a jet-pipe 08 pivoted at 89 and supplied with pressure fluid through a conduit 90 which is issued from the jet-pipe into reception orifices 9| and 92 depending upon the relative position of the jet-pipe and the orifices. A double armed lever 93 is pivotally mounted on the jet-pipe at 94, one arm of the lever being connected with the follower IT by means of a link 95, the other arm being connected to an angle lever 95 pivoted at 91 through a link 98. The angle lever 90 is moved in response to the movements of the piston of a servo-motor 98, the piston being connected with the angle lever through a link I05; The servo-motor is supplied with pressure fluid from the jet-pipe relay 98 through conduits I00, IN, and I02. A second repeater servo-motor having a cylinder I03 and a piston I04 movable therein may be provided between the conduits I III and I02 for purposes later to be described.

The servo-

motor

98, 99 is connected through a link I06 to actuate a movable lever I01 defining the position of the center 4 of the disk 41 (Figs. 1 and'2).

The operation of the device so far describedis as follows:

nection I05, 96 90 acting onlthe other end of the differential lever 93. Accordingly the piston of the servo-motor 99. will at all times assume a position which is a function of the lateral nation of the ship.

In response to the movements of the servomotor 99 the movable member I01 will cause an adiustment ofthe blades of the Schneider propeller by displacing the axis 4 relatively to the axis 2 as hereinbeforedescribed. The result is a change in direction of the force exerted by the propeller on the water. The force exerted on the ship by the propeller ina direction difle'rent from the direction of the longitudinal axis 5-5 will thus produce a moment about the lontudinal axis to counter-act the inclination of the ship and to erect the same.

The device so far described will effectively stabilize a shipe against lateral inclinations.

Instead of solely changing the direction of the force of the Schneider propeller it may alsobe advantageous to vary the magnitude of the propeller force. This can be achieved in the following manner. A second servo-motor having a cylinder I08 and a piston I09 movable therein is connected to the movable member IN. The

incli servo-motor I08, I09 is controlled by and supplied with pressure fluid from a control valve IIO connected to the servo-motor through conduits III and H2.

trol valve is moved from a diilerential lever II4 to which a restoring connection H5, H6, H1 is -linked, the other arm of the differential lever being controlled by a handle 8. A variable transmission device is inserted between the handle H8 and the differential lever. II4 including in the illustrated example slotted levers H9 and I pivoted at I2I and I22, respectively. A connecting member I 231engages with pins I24 and I25 the slots in-the'levers ll9and I20.. The. connecting member is pivotally connected to a rod I20 guided at I21 and provided with a pin I28 guided in a curved slot I29 of a cam member I30. The cam member is connected to be moved from the piston I04 and guided at I3I The position of the servo-motor-IllB, I09 controlling the movable member I0'I effects an adjustment of the pitch of the Schneider propeller.

It was explained in connection with Figs. 1

and 2 that in the position in which the axes 4 and 2 coincide, the pitch of the propeller blades is zero and the rotating blades will exert no force on the surrounding water. When the movable member I0! is displaced through the servo-motor I08, I09, the pitch of the'propeller blades determining the magnitude of the propeller force is varied. The pitch of the propeller blades is normally set by adjusting the handle IIO operating the control valves H0 and H3. Thegpredetermined pitch of the propeller set at the handle II 8 is now increased to vary the reaction force of the propeller on the water for the purpose of erecting the ship as follows.

When the ship is in its normal upright position, the servo-motors 99 and I03 will be in their central position. In thisinstance the member I23 0! the variable transmission device is in its uppermost position in which the ratio oi transmission between the handle IIO and the. difl'erential lever H4 is one to one. When, however, the ship assumes an inclination and the pistons of the servo-motors 99 and I03 become displaced, the pin I28 will travel in the curved slot I29 of the cam member I30 in a downward direction, increasing the ratio of transmission between the control handle H8 and the pitch controlling valve H0. The pitch of the propeller blades and accordingly the force of the propeller is thus The piston I I3 of the contorque is exerted on the ship.

increased resulting in an increased erecting moment on the ship.

Obviously, the present invention is not restricted to the particular embodiment herein shown and described. Other forms of inclination responsive devices may be used and other forms of control devices for adjusting the blades of the Schneider propeller be employed. Moreover, it is not indispensable that allthe features of this invention be used conjointly, since they may advantageously be employed in various combinations and subcombinations.

Thus, for example, the stabilizing device may be simplified by eliminating the elements of the device for changing the pitch of the propeller in response to inclinations of the ship. In this instance the repeater servo-motor I03, I04 may be omitted and the conduits IOI, I02 be connected at I32.

' being mounted on said body substantially below the center of gravity of the ship; power means for driving said propeller; and means responsive to lateral inclinations of the ship and connected to adjust said blades, whereby upon a lateral inclination the direction of the propelling force exerted by the propeller is varied and an erecting torque is exerted on the ship.

2. The combination with a ships body of apropeller having apluiality ofblades and a rotatable support for said blades on which said blades are adjustably mounted parallel with the axis of rotation of said support, said propeller being mounted on said body to protrude from the bottom thereof and at a horizontal distance from the ships center of gravity of less than one quarter of the ships length; power means for driving said propeller; and means responsive to lateral inclinations of the ship and connected to adjust said blades, whereby upon a lateral inclination the direction of the propelling force exerted by the propeller is varied and an erecting The combination with a ships body of a propeller having a plurality of blades a rotatable support for said blades on which said blades are adjustably mounted parallel with the axis of rotation of said support; means for mounting.

said propeller on said body to be projectible and retractable relatively to the bottom thereof and at a horizontal distance from the ships center of gravity offlessthan one quarter of the ship's length; power means for driving said propeller; and means responsive to lateral inclinations oi! the ship and connected to adjust said blades, whereby upon a lateral inclination the direction of the propelling force exerted by the propeller is varied and an erecting torque is exerted on I the, ship.

' including a servo-motor for adjusting said blades to vary the direction oftheir propelling action; means for mounting said propeller on said body The pitch controlling handle IIO will now control directly the control valves I I0 and 4 to protrude from the bottom thereof and at r horizontal distance from the ships center of gravity of less than one quarter of the ships length;

power means fordriving said propeller; andmeans responsive to lateral inclinations of the ship and connected to control said servo-motor, whereby upon a lateral inclination the direction of the propelling force exerted by the propeller is varied and an erecting torque is exerted on the ship.

5 The combination with a ship's body 01 a propeller having a plurality of blades and a rotatable support for said blades on which said blades are adjustably mounted parallel with-the axis of rotation of said support, said propeller including a first servo-motor for adjusting said blades to vary the direction of their propelling action and a second servo-motor for adjusting the pitch of the blades; means for mounting said