US3789758A

US3789758A - Force balance pressure device

Info

Publication number: US3789758A
Application number: US00639837A
Authority: US
Inventors: W Plice
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1957-02-12
Filing date: 1957-02-12
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05

Abstract

1. In a moored mine and mine anchor having a mooring cable, a force balancing system, said system comprises a pivoted bar, means for applying to one end of said bar a force proportional to the depth of the water in which the anchor rests when on the bottom, means responsive only to the pay out of the mooring cable for applying a force to said bar for counterbalancing the force applied to the one end of said bar, means actuated by said bar when the counterbalancing force exceeds the applied force to cause the pay out of the cable to stop.

Description

baited States Patent [191 Plice FORCE BALANCE PRESSURE DEVICE [75] Inventor: William A. Plice, Hopkins, Minn.

[73] Assignee: The United States of America as represented by the Secretary of the Navy, Washington, DC.

[22] Filed: Feb. 12, 1957 [21] Appl. No.: 639,837

[52] U.S.'Cl. 102/13 [51] Int. Cl 863i 3/02 [58] Field of Search 102/13, 14; 114/25 [5 6] References Cited FOREIGN PATENTS OR APPLICATIONS 471,919 9/1937 Great Britain 102/14 [111 3J7SJS [4 1 V Feb.5,1974

Primary Examiner-Robert F. Stahl Attorney, Agent, or Firm-R. S. Sciascia; J. A. Cooke; Q. E. Hodges EXEWLARY CLAIIM 1. In a moored mine and mine anchor having a mooring cable, a force balancing system, said system comprises a pivoted bar, means for applying to one end of said bar a force proportional to the depth of the water in which the anchor rests when on the bottom, means responsive only to the pay out of the mooring cable for applying a force to said bar for counterbalancing the force applied to the one end of said bar, means actuated by said bar when the counterbalancing force exceeds the applied force to cause the pay out of the cable to stop.

8 Claims, 3 Drawing Figures DISPENSER\ PATENIEDFEB 51914 3,789,758

SHEET 1 OF 2 MINE CABLE MEASURER FORCE BALANCE SWAGER SYSTEM m L CABLE DISPENSER BATTERY F E G.E i:- -1-= /C m $7 T T 1 EU W5 I 2 3 4 5 5 5 50;

POSITION INVENTOR WILLIAM A.'PL|OE BY ATTORNQFS FORCE BALANCE PRESSURE DEVICE This invention relates to a force balancing system for determining the mooring depth of an anchored mine. More specifically, the present invention provides means to automatically cause a positively buoyant mine to float at a predetermined depth no matter what the overall depth of the water may be, provided there is sufficient mooring cable to reach from the bottom to the predetermined depth of submersion of the mine.

The force balancing system of this invention provides a sensing device which responds to the depth to which the mine and mine anchor sinks in reaching the bottom and employs this information to measure off sufficient mooring cable as the mine rises toward the surface after release from the anchor to permit the mine to remain submerged at a predetermined depth below the surface. When the mine rises to this depth the force balancing or measuring device actuates a cable swaging device which may be of the type disclosed in copending application of Charles F. Bowersett for Explosive Swaging Device for Mooring a Submerged Mine Ser. No. 285,040 filed Apr. 29, 1952. In mine and anchor systems of the type in which this invention is employed, there is normally provided means for rendering the electrical circuits of the mine ineffective until the mine and anchor reach a minimum depth of water. Since such a means forms no part of the present invention, no

specific form of such device is shown. It might be, for

example, a hydrostatic switch of conventional design. The measurement of the length of the mooring cable is achieved by a plurality of magnetized spots spaced along the cable which may be detected and converted to a pulsing signal by a device such as that disclosed in the copending application of Leon J. Lofthus for Magnetic Cable Measuring Device, Ser. No.-285,039, filed Apr. 29, 1952 or any similar device which will producethe required signal to actuate the force balancing system of the present invention.

It is an object of the present invention to provide a new and improved means for automatically mooring a mine at a predetermined depth.

. It is another object of the present invention to provide means responsive to the depth of water for determining the amount of mooring cable released from the anchor. g

It is another object of this invention to provide a force balancing system responsive to the balancing force exceeding the unbalancing force to actuate a controlled circuit.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a pictorial view showing the mine in various stages of mooring.

FIG. 2 is a diagrammatic view of the mine employing the present invention.

FIG. 3 is a schematic view of the force-balance system of the present invention suitable for use with the mine of FIG. 2.

Referring now to the drawings, there is shown in FIG. 1 a pictorial illustration of the problem involved inlaying of moored mines of the type in which the present invention may be employed. The mine M with its anchor A are initially fastened together as shown in position 1 and remain closely fastened together until the mine and anchor reach the bottom as shown in position 2. After the mine reaches position 2 it is released from the close attachment to the anchor in any well known manner and allowed to rise through

successive positions

3 and 4, pulling out a mooring cable C-until the mine reaches a depth D as shown in position 5, at which time the mooring cable C is swaged to hold the mine below the surface of the water.

In prior devices of this type it was the usual practice to anticipate the depth of the water in which the mine would be laid and to set this depth into the cable measuring device. The mine using the present invention does not require such preliminary information. The force balancing system provides an automatic sensing of the depth of the water so that it is only necessary to decide at what depth the ,mine should float and to set that depth information into the force balancing system. Then, regardless of the maximum depth of the water, the mine will be moored at substantially the desired depth of submersion provided only that the mooring cable carried in the mine anchor is long enough.

. Referring to FIG. 2 there is shown diagrammatically a mine and anchor with those component parts of the anchoring system which function with the force bal ance system of the present invention. The anchoring system consists generally of the mine, the mine anchor in'which are mounted the force balance system of the present invention, a cable dispenser with a length of mooring cable, a cable swager, a cable measuring device and a power source, shown as a battery.

The force balance system diagrammed in FIG. 2 has one embodiment shown in FIG. 3. This illustrative embodiment comprises a lever 20 which may be of a ferromagnetic material and which is pivoted at 21 and has pivotally attached at one end 19 thereof a yoke 22. The other end 18 of the lever 20 carries an electrical contact 23 which forms a part of a normally open switch 24. This end 18 of lever 20 is positioned to receive the pressure exerted by the medium surrounding the mine which is transmitted through a bellows 25 and push rod 26. This bellows may be connected to the exterior ofa fluid tight container 30 which houses the force balancing mechanism through an opening 27 or may be mountedin an expansion chamber within the container 30 and connected to the external pressure through appropriate conduits not shown. The bellows may be surrounded by a cup 31 to prevent excessive expansion of the bellows. Also mounted adjacent the end 18 is a magnet, shown as a permanent magnet 32 which coacts with the push rod 26 to resist the closing of switch 24.

The yoke 22 has attached to it one pair of ends of a' pair of springs 33. The other pair of ends of the springs 33 are attached to a nut 34 which is threadedly engaged on a rotatable shaft 35. The nut 34 is prevented from rotating by the engagement of a pair of arms 36 with guides 37. The shaft 35 carries a ratchet wheel 38 fixed on it adjacent one end. The shaft 35 may be provided with a portion 39 which extends through its bearing mount and which has a slot4l cut axially into its end portion. A shaft 42 is mounted in container 30 and has a member 43 adapted to mate with slot 41 for manually rotating shaft 35. Shaft 42 extends outside the c'onca] pulses received from the cable measuring device, which is external of the container 30 as is shown diagrammatically and labeled in FIGS. 2 and 3 and whose construction forms no part of the present invention. The ratchet wheel has a conventional holding pawl, not shown.

Positioned to release'the pawl 44 is a cam 46. This cam is operated by push button 47 which is spring biased out of engagement with the pawl 44.

When the force of the springs 33 overcomes the force exerted by the push rod 26 and magnet 32, switch 24 is closed to operate the cable swaging device 48 to stop the payout of the cable and the rise of the mine. The cable swaging device 48 is also mounted outside container 30.

In the operation of the present invention the mine and anchor are dropped into the water and sink to the bottom. When the mine reaches the bottom a mechanism, not shown, which forms no part of the present invention, allows the mine to separate from the anchor. Since the mine is buoyant, it begins to rise and to pull out the mooring cable.

When the mine anchor sinks, pressure is applied to the bellows 25 and through push rod 26 to the end 18 of bar to tend to hold the switch 24 open. The cable measuring apparatus is actuated by the pulses produced by the paying out of the mooring cable as the mine rises. These pulses are applied to actuate the solenoid motor 45 which steps the ratchet wheel 38, in the illustrated embodiment, to tension the springs 33 until thespring overcomes the forces applied to end 18 of bar 20. The desired depth of mooring is initially set into the device by rotating shaft 35 in the desired direction using hand wheel 49. If it is necessary to rotate shaft 35 and ratchet wheel 38 against the pawl 44 the push button 47 is employed to cause cam 46 to release the pawl 44 and the holding pawl not shown.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

2. A device as claimed in claim 1 in which said means for applying a force comprises a bellows connected to receive the pressure from the water and a push rod for applying said force to said one end of said bar.

3. A device as claimed in claim 2 in which said means for counterbalancing comprises a spring attached at one end to said bar to produce a moment about the pivot, a screw rotatably mounted, a nut non-rotatably mounted on said screw and having means attaching the other end of said spring to said nut, a ratchet wheel attached to one end of said screw, a solenoid motor having a pawl mounted only to rotate said ratchet wheel in a direction to tension said spring.

4. A device as claimed in claim 3 having means for presetting the initial force of said spring for determining the depth below the surface the mine will be moored.

5. A device as claimed in claim 1 in which said bar is of magnetic material, a magnet mounted adjacent one end of said bar to bias said bar toward a position in which said actuated means is rendered inoperative.

6. In a moored mine and mine anchor having a mooring cable, a mine anchor casing having means for dispensing a length of cable stowedtherein, a force balancing system for mounting in said casing from which the surrounding medium is excluded comprising a push rod, a tubular bellows connecting said push rodto the casing, said casing having an opening therethrough for admitting the surrounding medium into said bellows, a

normally open electrical switch a pivoted lever carrying an electric contact at one end, said contact forming part of said switch, said push rod being positioned to bear on said one end, a spring attached to said lever to oppose the action of said push rod, means for increasing the force exerted by said spring in response to a signal sufficiently to close said switch, said signal being proportional to the amount of cable payed out from said anchor.

7. A device as claimed in claim 6 when used in an anchor device having a mooring cable for a member buoyant in said medium, in which said force increasing means comprises a motor actuated in response to the amount of a mooring cable payed out, a rotatably mounted threaded member, means connecting said motor to said threaded member for rotating said threaded member in a direction to tension and spring,

nut means non-rotatably mounted in threaded engagement with said member and attached to said spring.

8. A device as claimed in claim 6 in which a magnet is mounted adjacent to one end of said liner to oppose the movement of the lever in response to the force exerted by said spring.

Claims

6. In a moored mine and mine anchor having a mooring cable, a mine anchor casing having means for dispensing a length of cable stowed therein, a force balancing system for mounting in said casing from which the surrounding medium is excluded comprising a push rod, a tubular bellows connecting said push rod to the casing, said casing having an oPening therethrough for admitting the surrounding medium into said bellows, a normally open electrical switch a pivoted lever carrying an electric contact at one end, said contact forming part of said switch, said push rod being positioned to bear on said one end, a spring attached to said lever to oppose the action of said push rod, means for increasing the force exerted by said spring in response to a signal sufficiently to close said switch, said signal being proportional to the amount of cable payed out from said anchor.

7. A device as claimed in claim 6 when used in an anchor device having a mooring cable for a member buoyant in said medium, in which said force increasing means comprises a motor actuated in response to the amount of a mooring cable payed out, a rotatably mounted threaded member, means connecting said motor to said threaded member for rotating said threaded member in a direction to tension and spring, nut means non-rotatably mounted in threaded engagement with said member and attached to said spring.