US3906883A

US3906883A - Stabilizer fin control system for a towed buoy

Info

Publication number: US3906883A
Application number: US441692A
Authority: US
Inventors: Charles Peter Majkrzak
Original assignee: Deutsche ITT Industries GmbH
Current assignee: TDK Micronas GmbH; ITT Inc
Priority date: 1974-02-22
Filing date: 1974-02-22
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23

Abstract

A mechanical load sensing arrangement is disposed at the buoy tow point and is coupled to the tow cable. This load sensing arrangement is mechanically displaced proportional to tensile loading of the cable. A mechanical stabilizer fin attitude control arrangement is interconnected between the stabilizer fin and the load sensing arrangement. The attitude control arrangement is responsive to the mechanical displacement of the load sensing arrangement to control the stabilizer fin to assume a low-lift attitude when the tensile loading exceeds a first given amount and to assume a normal lift attitude when the tensile loading is less than a second given amount, where the second given amount is less than the first given amount.

Description

li 253. OR 3.906.883 SR United States Patent 1191 1111 s, u6,66s Majkrzak Sept. 23, 1975 STABILIZER FIN CONTROL SYSTEM FOR A TOWED BUOY Primary ExaminerTrygve M. Blix Assistant ExaminerSherman D. Basinger [75] Inventor. ghjarles Peter Ma krzak, Nutley, Anomey, Agent or Firm JOhn T UHaHoram Menotti J. Lombardi, Jr.; Alfred C. Hill [73] Assignee: International Telephone and Telegraph Corporation, Nutley, NJ. [57] ABSTRACT [22] Filed: 22 1974 A mechanical load sensing arrangement is disposed at the buoy tow point and is coupled to the tow cable. PP 441,692 This load sensing arrangement is mechanically displaced proportional to tensile loading of the cable. A

52 U.S. c1 114/235 B meenanieel Stabilizer fin attitude eennol arrangement 51 1111. c1. B63B 21/56 is interconnected between the Stabilizer fin and the 5 Field f Search u 114/235 R, 235 B, 236; load sensing arrangement. The attitude control ar- 74/469 470 rangement is responsive to the mechanical displacement of the load sensing arrangement to control the [56] References Cited stabilizer fin to assume a low-lift attitude when the UNITED STATES PATENTS tensile loading exceeds a first given amount and to assume a normal lift attitude when the tensile loading is 2,945,469 7 1960 Pu1s1fer 114/235 B less than a Second given amount, where the Second 22m 2: 3 given amount is less than the first given amount.

3,618,555 11/1971 Kelly et a1. 114/235 B 9 Claims, 5 Drawing Figures OCQLE as} US Patent se t.23,1975 SW20 3,906,883

H34 oomu 3 o US Patent Sept. 23,1975 Sheet 3 of3 3,906,883

.l i mmd 000m HMDJOOOm x mm 00 mm mm y mY NWM U STABILIZER FIN CONTROL SYSTEM FOR A TOWEI) BUOY BACKGROUND OF THE INVENTION This invention relates to submarine antenna buoys and more particularly to an arrangement associated with the buoy to prevent cable rupture.

During tow by a submarine, the tensile loading within the tow cable is normally greater at the buoy tow point than at the tow winch aboard the submarine. To prevent loss of a buoy through cable rupture by excessive loading before such loading can be sensed and compensation for at the winch, a load sensing arrangement needs to be incorporated at the tow point to instantaneously sense local cable tension. Excessive cable load can than be relieved by decreasing the demand for lift by the buoy.

In normal use, the buoy is towed in a defined normal attitude to produce a normal lift. When cable tension exceeds 5,000 pounds, as it may in high velocity tow or with abnormal transient conditions, this attitude must be altered to a low-lift condition to relieve cable tension. This is accomplished through the use of a trimming stabilizer fin within the buoys horizontal hydrofoil. When tow velocity or abnormal cable load is decreased to below 2,500 pounds, the trimming stabilizer fin readjusts so as to return the buoys attitude to normal lift.

Stabilization can be achieved by sensing cable loads directly at the tow point of the buoy where such loads are maximum. In the past this has been accomplished by employing an electrical sensing and servo-operated stabilizing system with a strain-gage-type sensor at the tow point. This has an advantage of enabling a control of the buoy's attitude from inboard the submarines. However, such an electrical arrangement requires transmission of large amounts of electrical power in the tow cable, results in source of electrical noise which could cause static in the radio frequency signals received by an antenna contained in the buoy and is rather complex and, thus, the reliability of the electrical system is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mechanical control system in the buoy to control the attitude of the stabilizer fin.

Another object of the present invention is to provide a mechanical control system for the stabilizer fin of a towed buoy which minimizes transmission of electrical power in the tow cable, eliminates a source of electrical noise and increases reliability through simplicity.

A feature of the present invention is the provision of a stabilizer fin control system for a towed hollow buoy comprising: a tow cable for the buoy; a stabilizer fin for the buoy; a first mechanical means disposed at the buoy coupled to the cable, the first means being mechanically displaced proportional to tensile loading of the cable; and a second mechanical means interconnected between the stabilizer fin and the first means, the second means being responsive to the mechanical displacement of the first means to control the stabilizer fin to assume a low-lift attitude when the tensile loading exceeds a first given amount and to assume a normal lift attitude when the tensile loading is less than a second given amount, the first given amount being greater than the second given amount.

BRIEF DESCRIPTION OF THE DRAWING bilizer fin attitude control arrangement in its'flipping position with impending flip of the stabilizer fin from its normal lift position to its low-lift position;

FIG. 4 is a schematic diagram of the mechanical stabilizer fin attitude control arrangement in its flipped position with the stabilizer fin in its low-lift position; and

FIG. 5 is a schematic diagram of the mechanical stabilizer fin attitude control arrangement in its re-flipping position with the stabilizer fin in an impending flip from its low-lift position to normal lift position.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there is illustrated schematically a stabilizer fin control system for a towed hollow buoy in accordance with the principles of the present invention. The control system includes a mechanical load sensing arrangement 1 disposed at the buoy coupled to tow cable 2 with arrangement 1 being mechanically displaced proportional to the tensile loading of cable 2 and a mechanical stabilizer fin attitude control arrangement 3 interconnected between stabilizer fin 4 and arrangement l with arrangement 3 being responsive to the mechanical displacement of arrangement 1 to control stabilizer fin 4 to assume a low-lift attitude when the tensile loading of cable 2 exceeds a first given amount and to assume a normal lift attitude when the tensile loading of cable 2 is less than a second given amount, where the first given amount is greater than the second given amount. I

Cable 2 includes internally thereof electrical cable 5 to supply electrical power to electrical apparatus contained within the buoy, such as the winch motor employed to control the erection and retraction of a communication antenna contained within the buoy.

Stabilizer fin 4 is in practice actually formed in two sections, one section being disposed in the buoys horizontal hydrofoil on one side of the buoy and the other section being disposed in the buoys horizontal hydrofoil on the other side of the buoy, with these two sections of the stabilizer fin being interconnected by a connecting rod upon which arrangement 3 operates to simultaneously control the two sections to assume the same attitude.

Arrangement 1 includes a hollow cylindrical'member i 6 having a longitudinal axis and a pair of

slots

7 and 8 parallel to the longitudinal axis and diametrically opposite each' other with member 6 being connected to the outer surface of the buoy adjacent the tow point. Arrangement 1 also includes a housing 9 connected to the inner surface of the buoy disposed coaxially of an extension of the longitudinal axis of member 6. Member FIG. 3 is a schematic diagram of the mechanical sta- 6 and housing 9 may be connected to the appropriate location of the buoy hull 10 by providing a flange 11 on member 6 and a flange 12 on housing 9 with each of these

flanges

11 and 12 having apertures therein aligned with each other and aperatures in the hull 10. The aperatures in flange 12 are tapped to receive bolts 13 so as to enable the connection of member 6 and housing 9 to hull 10 at the tow point.

Arrangement 1 further includes a cylindrical element 14 disposed within member 6 coaxial of its longitudinal axis in a longitudinal sliding relationship with the interior of member 6. Element 14 includes a pair of

projections

15 and 16 adjacent the upper end of element 14 diametrically opposite each other. Projections l5 and 16 slideably engage an associated one of

slots

7 and 8 to permit displacement of element 14 when tow cable 2 is under a load. Electro-mechanical planar clevis 17 connects the lower end of element 14 to cable 2. An inverted cup-shaped member 18 having a bottom 19 is slideably disposed in housing 9 coaxial of the extension of the longitudinal axis of member 6. A mechanical load displacement device 20 is disposed within inverted cup member 18 between bottom 19 and a wall 21 adjacent the inner surface of the buoy. Tie bar 22 is connected to the upper end of element 14 and extends through hull 10 of the buoy, through the load displacement device 20 and beyond the bottom 19 of inverted cup-shaped member 18 coaxial of the longitudinal axis of member 6 and the extension of this axis. Bar 22 is fastened to bottom 19, such as by nut 23, so that bottom 19 and, hence, the cup-shaped member 18 may be displaced downward when the load increases on cable 2. An arm 24 is connected to bar 22 adjacent the end that extends beyond bottom 19 of the inverted cupshaped member 18 with this arm carrying actuator 25 in the form of a pin.

Arrangement 3 includes a link 26 having an elongated slot 27 adjacent the upper end thereof into which actuator 25 is slideably received. A spring-loaded snap toggle 28 has one end thereof pivotably connected to the lower end of link 26 and its other end connected to a mechanical push-pull cable 29. Pushpull cable 29 includes an outer metallic sleeve 30 with the ends thereof being secured against physical motion in

buoy partitions

31 and 32, respectively, and a mechanically moveable member 33 contained within the outer sleeve 30. This element 33 will be pushed or pulled in response to toggle 28. End 34 of element 33 is pivotably connected to the other end of toggle 28 while end 35 of member 33 is connected to link 36 having an elongated slot 37 substantially throughout its length. Follower 38 is slideably received in slot 37 and responds to motion of link 36 so that spring-loaded snap toggle 39 can control the attitude of stabilizer fin 4. Spring 40 of toggle 39 will maintain stabilizer fin 4 in either of the two attitudes it is caused to assume by arrangement 3. The attitude assumed will be dependent upon the tensile loading of cable 2.

The force from loaded tow cable 2 produces a proportional deflection of device 20 and, hence, actuator 25 which is transmitted through link 26, toggle 28, push-pull cable 29, link 36 and toggle 39 to stabilizer fin 4. The mechanical load displacement device 20 may be any of several different types of load displacement components, such as a coil spring, a captive mass of rubber with proper bulk modulus of compression or Belleville springs. By way of example device 20 containing 35 Belleville spring units of lnconel X at 2 inch diameter and 0.058 inches thick and operating at a maximum stress of 100,000 pounds per square inch at flat loading will displace actuator 25 to a practical length to 0.575 inches at a 5,000 pound load.

Referring to FIGS. 2-5 the operation of arrangement 3 for various load conditions will now be discussed.

When the cable load is transferred through device 20, actuator 25 moves within slot 27 of link 26 connected to toggle 28 so that at 2,500 pounds actuator 25 is at the bottom of slot 27 and no effective transfer of load has been made to toggle 28 until the 2,500 pounds of cable load is exceeded. At this point actuator 25 begins to transfer load through link 26 to toggle 28. A further increase in load will actuate toggle 28 from its normal position of FIG. 2 to a flipping position for toggle 28 as illustrated in FIG. 3. It will be noted in FIG. 2 that follower 38 is in the approximate center of slot 37 and link 36 is in its retracted position and stabilizer fin 4 is in its normal lift attitude. In the flipping position of FIG. 3 follower 38 is at the bottom of slot 37 with link 36 in its mean position and stabilizer fin 4 in an impending flip condition from a normal lift position to a low-lift position. When the load increases beyond 5,000 pounds toggle 28 flips to its second stable position and toggle 39 flips to its second stable position. When toggle 39 flips to its second stable position, stabilizer fin 4 is flipped to a low-lift attitude as illustrated in FIG. 4. It will be noted in FIG. 4 that actuator 25 is at the top of slot 27 and that link 36 is in its extended position with follower 38 approximately in the center of slot 37. During this sequence of operation as illustrated in FIGS. 2, 3 and 4, stabilizer fin 4 has remained in a normal trim position and was caused to flip into and held at a low-lift position when toggles 28 and 39 were flipped.

As the cable tension or load is reduced from 5,000 pounds, toggle 28 moves toward its re-flipping position until the 2,500 pound level is reached and toggle 28 is in its re-flipping position as illustrated in FIG. 5. As illustrated in FIG. 5 actuator 25 is at the top of slot 27 and toggle 28 has moved into its re-flipping position while link 36 has been pulled by push-pull cable 39 to its mean position and follower 38 is at the top of slot 37. A decrease of the load below 2,500 pounds causes actuator 25 to flip toggle 28 into the position illustrated in FIG. 2 which will cause link 36 to pull follower 38 down through means of push-pull cable 29. When link 36 reaches its retracted position toggle 39 will cause stabilizer fin 4 to flip to its normal lift attitude as illustrated in FIG. 2.

In the above sequence of operation there is a stepped control of the stabilizer fin 4 at 5,000 pounds and 2,500 pounds. The control system of this invention, however, is also readily capable to automatically provide continual attitude control over the cable-load range. This continual attitude control is accomplished by replacing the control slots in

links

26 and 36 with pin joints.

While I have described above the principles of my invention in connection with specific apparatus it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.

I claim:

wabiliae fimcqn l .sy e .fQr at me imllgw b u oy comprisingz 5 second mechanical means interconnected between said stabilizer fin and said first means, said second means being responsive to the mechanical displacement of said first means to control said stabilizer fin to assume a low-lift attitude when said tensile loading exceeds a first given amount and to assume a normal lift attitude when said tensile loading is less than a second given amount, said first given amount being greater than said second given amount;

said first means including a hollow cylindrical member having a longitudinal axis and a pair of elongated slots parallel to said axis and diametrically opposite each other, said cylindrical member being connected to the outer surface of said buoy adjacent a tow point,

a cylindrical element disposed within said cylindrical member coaxial of said axis in a longitudinal sliding relation with said cylindrical member, said cylindrical element having a pair of projections adjacent one end thereof diametrically opposite each other, each of said pair of projections slideably engaging a different one of said pair of slots,

a planar clevis connecting the other end of said cylindrical element to said cable,

a cylindrical housing connected to the inner surface of said buoy disposed coaxial to an extension of said axis,

an inverted cup-shaped member slideably disposed in said housing coaxial of said extension of said axis,

a mechanical load displacement device disposed within said inverted cup-shaped member between the bottom thereof and the inner surface of said buoy,

a bar connected to said one end of said cylindrical element extending through a wall of said buoy, through said load displacement device and beyond the bottom of said inverted cup-shaped member coaxial of said axis and said extension of said axis, said bar being secured to the bottom of said cup-shaped member,

an arm connected to said bar adjacent the end thereof that extends beyond the bottom of said inverted cup-shaped member, and

an actuator carried by said arm to control said second means.

2. A control system according to claim 1, wherein said load displacement device includes a resilient member.

3. A control system according to claim 2, wherein said resilient member includes a captive rubber member.

4. A control system according to claim 2, wherein said resilient member includes a coil spring.

5. A control system according to claim 2, wherein said resilient member includes Belleville springs.

6. A control system according to claim 1, wherein said second means includes a first link having an elongated slot adjacent one end thereof into which said actuator is slideably received,

a first snap toggle having one end thereof pivotably connected to the other end of said first link,

a mechanical push-pull cable having each end thereof mounted to a partition within said buoy, one end of said push-pull cable being pivotably connected to the other end of said first toggle,

a second link having an elongated slot substantially throughout its length, said second link being connected to the other end of said push-pull cable,

a follower slideably received in said elongated slot of said second link, and

a second snap toggle connected between said follower and said stabilizer fin.

7. A control system according to claim 6, wherein said second toggle includes a spring having one end connected to a fixed point and the other end connected to said stabilizer fin to maintain said stabilizer fin in either of its assumed attitudes.

8. A stabilizer fin control systemfor a towed hollow buoy comprising: i

a tow cable for said buoy;

a stabilizer fin for said buoy;

a first mechanical means disposed at said buoy coupled to said cable, said first means being mechanically displaced proportional to tensile loading of said cable; and q a second mechanical means interconnected between said stabilizer fin and said first means, said second means being responsive to the mechanical displacement of said first means to control said stabilizer fin to assume a low-lift attitude when said tensile loading exceeds a first given amount and to assume a normal lift attitude when said tensile loading is less than a second given amount, said first given amount being greater than said second given amount;

said second means including a first link having an elongated slot adjacent one end thereof into which an actuator controlled by said first means is slideably received,

a follower slideably received in said elongated slot of said second link, and

a second snap toggle connected between said follower and said stabilizer fin.

9. A control system according to claim 8, wherein said second toggle includes a spring having one end connected to a fixed point and the other end connected to said stabilizer fin to maintain said stabilizer fin in either of its assumed attitudes.

Claims

1. A stabilizer fin control system for a towed hollow buoy comprising: a tow cable for said buoy; a stabilizer fin for said buoy; a first mechanical means disposed at said buoy coupled to said cable, said first means being mechanically displaced proportional to tensile loading of said cable; and a second mechanical means interconnected between said stabilizer fin and said first means, said second means being responsive to the mechanical displacement of said first means to control said stabilizer fin to assume a low-lift attitude when said tensile loading exceeds a first given amount and to assume a normal lift attitude when said tensile loading is less than a second given amount, said first given amount being greater than said second given amount; said first means including a hollow cylindrical member having a longitudinal axis and a pair of elongated slots parallel to said axis and diametrically opposite each other, said cylindrical member being connected to the outer surface of said buoy adjacent a tow point, a cylindrical element disposed within said cylindrical member coaxial of said axis in A longitudinal sliding relation with said cylindrical member, said cylindrical element having a pair of projections adjacent one end thereof diametrically opposite each other, each of said pair of projections slideably engaging a different one of said pair of slots, a planar clevis connecting the other end of said cylindrical element to said cable, a cylindrical housing connected to the inner surface of said buoy disposed coaxial to an extension of said axis, an inverted cup-shaped member slideably disposed in said housing coaxial of said extension of said axis, a mechanical load displacement device disposed within said inverted cup-shaped member between the bottom thereof and the inner surface of said buoy, a bar connected to said one end of said cylindrical element extending through a wall of said buoy, through said load displacement device and beyond the bottom of said inverted cup-shaped member coaxial of said axis and said extension of said axis, said bar being secured to the bottom of said cupshaped member, an arm connected to said bar adjacent the end thereof that extends beyond the bottom of said inverted cup-shaped member, and an actuator carried by said arm to control said second means.

6. A control system according to claim 1, wherein said second means includes a first link having an elongated slot adjacent one end thereof into which said actuator is slideably received, a first snap toggle having one end thereof pivotably connected to the other end of said first link, a mechanical push-pull cable having each end thereof mounted to a partition within said buoy, one end of said push-pull cable being pivotably connected to the other end of said first toggle, a second link having an elongated slot substantially throughout its length, said second link being connected to the other end of said push-pull cable, a follower slideably received in said elongated slot of said second link, and a second snap toggle connected between said follower and said stabilizer fin.

8. A stabilizer fin control system for a towed hollow buoy comprising: a tow cable for said buoy; a stabilizer fin for said buoy; a first mechanical means disposed at said buoy coupled to said cable, said first means being mechanically displaced proportional to tensile loading of said cable; and a second mechanical means interconnected between said stabilizer fin and said first means, said second means being responsive to the mechanical displacement of said first means to control said stabilizer fin to assume a low-lift attitude when said tensile loading exceeds a first given amount and to assume a normal lift attitude when said tensile loading is less than a second given amount, said first given amount being greater than said second given amount; said second means including a first link having an elongated slot adjacent one end thereof into which an actuator controlled by said first means is slideably received, a first snap toggle having one end thereof pivotably connected to the other end of said first link, a mechanical push-pull cable having each end thereof mounted to a partition within said buoy, one end of said push-pull cable being pivotably connected to the other end of said first toggle, a seCond link having an elongated slot substantially throughout its length, said second link being connected to the other end of said push-pull cable, a follower slideably received in said elongated slot of said second link, and a second snap toggle connected between said follower and said stabilizer fin.