US3170433A

US3170433A - Imbedment anchor assembly

Info

Publication number: US3170433A
Application number: US250589A
Authority: US
Inventors: John T Gardiner
Original assignee: Pneumo Dynamics Corp
Current assignee: Pneumo Dynamics Corp
Priority date: 1963-01-10
Filing date: 1963-01-10
Publication date: 1965-02-23
Anticipated expiration: 1982-02-23
Also published as: ES294289A1; BE641456A; GB998424A; DK115451B; BE641416A; NL301137A; NL142364B

Description

Feb. 23, 1965 .1. T. GARDINER IMBEDMENT ANCHOR ASSEMBLY 5 Sheets-Sheet 1 Filed Jan. 10, 1963 INVENTOR.

JOHN T. GARDINER ATTORNEY Feb. 23, 1965 J. T. GARDINER 3,170,433

IMBEDMENT ANCHOR ASSEMBLY Filed Jan. 10, 1963 5 Sheets-Sheet 3 llOd W H00 72 IIO HYDROSTATIC PRESSURE CONTACT PRESSURE INVENTOR.

JOHN T, GARDINER Gamma 9mm ATTORNEY Feb. 23, 1965 J. T. GARDINER 3,170,433

IMBEDMENT ANCHOR ASSEMBLY Filed Jan. 10, 1963 s Sheets-Sheet 4 FIG. 4

INVENTOR JOHN T GARDINER GQYAMRWM ATTORNEY Feb. 23, 1965 J. T. GARDINER 3,170,433

IMBEIDMENT ANCHOR ASSEMBLY Filed Jan. 10, 1963 5 Sheets-Sheet 5 INVENTOR.

JOHN T. GARDINER M AWW A TTORNE Y United States Patent 3,170,433 IMBEDMENT ANCHOR ASSEMBLY John T. Gardiner, Monrovia, Calif., assignor to Pneumo- Dynamics Corporation, Cleveland, Ohio, a corporation of Delaware 7 Filed Jan. 10, 1963, Ser. No. 250,589 4 Claims. (Cl. 114-206) This invention relates to imbedment anchors and more particularly to imbedment anchors of the type wherein an explosive charge is used to drive the anchor into the ocean bottom, with the anchor being subsequently oriented to provide the maximum holding power.

Such anchors comprise, as is well understood in the art, a projectile or anchor assembly and a recoil or reaction assembly between which, in normally combined form, the explosive charge is carried and effective when suitably detonated to separate the two forcibly, with the aforenoted result of driving the anchor assembly into the bottom of the body of water. The constructions which have previously been employed for this purpose have been such that both assemblies are lost or necessarily discarded with termination of the anchorage, a typical anchor use resulting in the projectile being irretrievably bedded in the bottom and the reaction assembly left tied to the anchor cable; the latter must of course be severed to free the vessel.

It is a primary object of the present invention to provide such an explosive anchor having a recoverable and reusable reaction or recoil assembly.

Another important object is to provide a construction for such an anchor in which there is a further separation of anchor components substantially immediately following the major separation of the projectile assembly and the recoil assembly whereby less resistance is oifered to the subsequent orienting of the projectile assembly.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is an elevational view of an explosive anchor in accordance with the invention, certain portions being broken away to expose the interior thereof;

FIG. 2 is an enlarged fragmentary view taken on line 22 of FIG. 1 showing more clearly certain portions of the projectile assembly of this anchor;

FIG. 3 is a schematic electrical diagram showing the circuit for electrically igniting the explosive charge;

FIG. 4 is an enlarged fragmentary view more clearly showing certain portions of the imbedment anchor;

FIG. 5 is a schematic view of a vessel, showing the imbedment anchor being lowered therefrom;

FIG. 6 is a schematic view showing the anchor immediately after imbedment with the recoil assembly and cylinder shown separated from the projectile assembly; and

FIG. 7 is a schematic view showing the projectile as sembly in its final, holding position.

Referring now to the drawings in detail, and particularly to FIG. 1, the imbedment anchor of the invention is generally indicated at 10 and comprises a projectile assembly designated generally by reference numeral 12 and a recoil or reaction assembly generally indicated at 14. The recoil assembly comprises a barrel portion 16 and 3,170,433 Patented Feb. 23, 1965 a drag plate 26, the latter being provided with a tubular sleeve 18 which forms a central hub telescoped on said barrel. The drag plate 26 is longitudinally positioned on the barrel 16 by means of a ring 28 which preferably comprises a pair of mating halves connected together in any suitable manner to seat the ring in an annular groove 30 formed in the barrel. The relatively large size of the drag plate 26 greatly assists the driving of the projectile assembly into the ocean floor, as will be further explained below.

The recoil assembly 14 further comprises a breech block 32 which is threadedly received in the outer end of the barrel l6 and serves to enclose an explosive charge contained within the barrel 16. The breech block is provided with a preferably integral outwardly extending cable receiving member 34, and a cable 36 extends from the latter. The cable is connected in the usual manner to a suitable cable control means on the vessel to be anchored for controlled lowering of the anchor to the ocean floor. Further, in accordance with the present invention, the winding of the cable 36 subsequent to the imbedment of the projectile in the ocean floor enables the recoil assembly 14 to be retrieved for further use.

The recoil assembly 14 is detachably connected to the projectile assembly 12 by means of clevis members 38 which extend through apertures in the drag plate 26 and are suitably secured thereto. The clevis members 38 are provided with bifurcated end portions 40 which are connected by means of bolts 42 to plates 44 which form part of the projectile assembly. As will be further explained below, the bolts 42 are adapted to shear when the anchor engages the bottom and the explosive charge detonated.

The projectile assembly 12 comprises a tubular member 46 having the above-mentioned plates 44 rigidly secured thereto and extending outwardly in diametric opposition. A nose cone 48 is mounted in the leading end of the projectile assembly and is provided with an enlarged diameter portion 50, the forwardmost edge of which provides a stop for a stand-off tube 52, the latter being frangible to break when contact is made with the ocean floor. The tube 52 is, however, necessarily strong enough to withstand the initial impact whereby the tube forces the nose cone 48 rearwardly through engagement with the enlarged portion 50, thereby igniting the explosive charge in a manner to be further described below. A safety ring 53, shown in the enlarged FIG. 2 showing of the projectile assembly, is disposed between enlarged portion 50 and the forwardmost end of tube 46 and functions in known manner to prevent accidental detonation while handling the anchor, the safety ring being removed before lowering the anchor into the water. A plurality of 'circurnferentially spaced shear screws 54 are provided which extend into threaded openings in the stem portion of the nose cone and serve to prevent the explosive charge from ignition due to hydrostatic pressure encountered as the anchor descends. The groove engaging portions of the screws 54 are sheared off when the anchor strikes the ocean floor thereby enabling the nose cone 48 to move rearwardly, or to the right as viewed in FIG. 2, thereby closing the circuit from the current source to the explosive, as further described hereinbelow.

The tube 46 has mounted on the exterior thereof be tween plates 44 a cable attaching member 55 which receives and holds a bifurcated member 56 to which the end of a second cable 58 is secured. The cable 58 also extends to suitable cable control apparatus mounted on the vessel.

The projectile assembly 12 is operatively connected to an ejection plug 60, which is received in an annular internal groove 62 in the tube 46, and a cylinder or sleeve 64 which is tightly received in the bore 66 of the barrel 16. An explosive cartridge assembly generally indicated wire 71.

The means for igniting the explosive charge 76 is shown A in FIG. 2 and it will be seen therein that the nose done 48 is provided with a stem 80 extending into the end of the tube 46, an O-ring 82 being. seated in. an annular groove in the stem to seal the interior of the tube 46 thereby preventing ingress of water. The stem 80 is provided with a bore 84 holding a pair of dry cell batteries 86 which provide the source of current for electrically igniting the explosive charge. The batteries 86 are held in position by a flanged, switch-actuating member 88 by means of screws 96 which are threadedly received in stem 66, there being an insulating member 91 disposed between actuator 88 and the end of the stem 80., The switch actuator 88 is provided with a circular depression 92 in the opposite end thereof, the bottom of such depressed portion of the switch actuator serving to contact and close a contact switch 94 in a manner hereinafter described.

The contact switch 94 is a conventional type switch forming no part of the present invention and is adapted to remain open relative to the current source 86 until the anchor strikes the sea floor. Control switch 94 is carried by a mounting member 96, the latter being provided with a peripheral flange 98 for mounting thereof in a switch holder member 160. The holder 160 is retained in the tube 46 by means of a set screw 101 as clearly illustrated. The switch holder 100 is further provided with an annular peripheral passage 162 which communicates with the exterior of the anchor through an opening 104 in the tube 46, whereby water isadmitted to the anchor interior. The water is of course at a pressure proportional to .the depth and flows through open ihg 104, passage 162, and passage 106 into contact with the actuating stem 168 of a pressure switch 110, the switch 110 being mounted on the holder 190 in any suitable manner. The pressure switch 110 is of the wellknown type that closes responsive to a predetermined pressure and forms no part of the present invention. When used in the environment of the invention, the switch 110 remains open until a pressure is attained proportional to a predetermined water depth, whereby the explosive cannot be inadvertently and prematurely electrically ignitedwhile handling the anchor. Wire 71 above referred to leads from the end of switch 110 to the cartridge assembly 68. Electrical wiring is of course connected, as shown, between the electrical source 86 the circuit components above described, and the resistance element 72 for conducting current thereto.

The electrical system for igniting the explosive is best described by referring to the schematic wiring diagram illustrated in FIG. 3. As noted above, both switches'94 and 110 are open when the anchor begins its descent.

Referring initially to pressure switch 110, the resistance element 72 is connected through contact 116a, movable contact member 1161) and contact 110s to ground, whereby switch 116 is open relative to contact switch 94. It will be seen that until the contact member lltlb closely approaches leads 110a and 110e, element 72 will remain grounded. When a predetermined depth has been reached, the hydrostatic pressure will be suflicient for closing contact member litlb on terminal contacts 110d, and 110e, as shown in dotted lines, whereby a circuit is established through element 72, contact 116a, terminal contact 110d, contact member 110b, terminal contact 110e, contact 116,, and lead wire 116g, the latter leading to one terminal of the contact switch 94.

Until the anchor strikes bottom, switch 94 remains open relative to the current source 86 in a manner similar to that described above with'reference to pressure switch 94. Thus, until such striking, the lead line 110g from switch 110 is grounded through contact 94a, contact member 9415 and contact 940. When the imbedment anchor strikes bottom, the contact member 94b closes. on contact terminals 94d and '94e, as shown in dotted 1ines,-whereby current isestablished from source r 86 through contact 94 contact member 94b, and contact 94a to' lead wire 110g of the pressure switch 110 whereby current is conducted to resistance element 72 thereby igniting the explosive and driving the nose cone 48 into the ocean floor. It will thus be seen that preignition of the explosive is effectively prevented until contact is made With'the ocean floor. 7

Referring now to the manner in which the cylinder 64 is separated from the projectile assembly '12 after impact with theocean floor, and particularly to FIG; 4, as mentioned above the ejection plug 60 is tightly held in annular groove 62 formed in the tube 46. The plug 66 is formed with an annular flange or'shoulder 112 which seats on the end of tube 46, the flange being provided with an O-ring'seal 113 toseal the interface between the periphery of the flange 11.2 and the axially offset forward cylindrical portion 114 of the cylinder 64. An annular chamber 116 is thus formed by the forward portion 114, theend of shoulder 112jand the periphery of the ejector plug6tl, the chamber 116 receiving gases from the ignition of the explosive 70.

The ejection plug dtlis formed with a reduced diameter end portion 118 disposed within the inner wall of cylinder 64 and a carbon ring 122 is provided disposed in an annular groove in such end portion for admitting the high pressure, gas from the explosion into the chamber 116 for a purpose hereinafterrelated. f 7

When the-explosiveisignited, the expansion of gases within cylinder 64 causes the shearing of bolts 42 thereby disconnecting the recoil assembly 14 from the projectile assembly 12 and causes the latter to be driveninto the ocean floor. The cylinder 6 l remains o peratively connected to the projectile assembly at this sta ge of the imbedment process. The high pressure gases enter chamber 116 past the. carbon ring 122. Subsequent. to the disconnection of the recoil assembly 14 from the projectile assembly 12, the pressure inside the cylinder 64 will of course drop to a level below the pressure level of the gases within annular chamber 116 whereby the pressure within the latter causes separation of the cylinder 64 from the ejection plug 60. The separation of the cylinder 64, which is of course not recoverable, from the projectile assembly 12 enables the latter to be oriented significantly more easily through tensioning'of the cable'SS due to the reduced weight of the projectile assembly;

As noted in both FIGS. 1 and 3, the ejection plug 60 is provided with an axial opening for passage of wire 71 therethrough, the wire 71 passing in the above-described manner to the cartridge assembly 68 and, more specifically, to the resistance element 72.

FIGS. 5-7 illustrate schematically and sequentially the anchor lowering and imb-edding process. Referring to FIG. 5, the anchor 16 is lowered by

cables

36 and 58 from the vessel V. When the anchor contacts the ocean floor the recoil assembly 14 and the piston 64 are in that orderdisconnected from the projectile assembly 12, the latter firmly imbedding itself as shown in FIG. 6. Finally, as shown in FIG. 7, the tensioning of cable 58 keys the projectile assembly 12 to a position generally horizontal thereby firmly anchoring the projectile assembly 12 in the ocean floor. As set forth above, the recoil assembly 14 is recoverable for reuseby merely winding the cable 36 from the vessel V; When the vessel. is'desired to be moved, the cable 58 is cut thereby freeing the vessel from its anchor.

More particularly, the imbedment anchor at the time it is being handled aboard the vessel is eflectively disarmed by means of the safety ring 53 and of course the safety features residing in the electrical system. Just before lowering, the safety ring 53 is removed. After a predetermined water depth is reached, switch 110, being pressure responsive, is closed by means of hydrostatic pressure thereby conditioning the electrical circuit for closing upon contact of the anchor with the bottom of the body of water. Stabilization of the anchor is assisted during descent by the plates 44 which form a major element of the projectile assembly, the

cables

36 and 58 being unwound for lowering the anchor as above described.

When the imbedment anchor reaches the bottom of the body of water, the anchor will make contact therewith through the frangible tube 52, the force of such contact shearing the bottoms of the shear screws 54 thereby freeing the nose cone 48 for movement inwardly relative to the tube 46. The inward movement of cone 48 causes the switch actuator 88 which is secured thereto to close the contact switch 94 thereby completing the circuit to resistance element 72. Current is thus carried through the electrical circuit from the source 86 thereby igniting the explosive charge 70. Upon ignition of the explosive charge 70, the force of such ignition causes bolts 42 to be sheared thereby propelling the projectile assembly downwardly away from the recoil assembly. The separation of the projectile assembly from the recoil assembly is significantly enhanced by the relatively large diameter drag plate 26 which provides considerable resistance to upward forces created by the explosion whereby a major portion of the energy is available to propel the projectile assembly downwardly into the bottom. After this initial stage of imbedment of the anchor and separation of the projectile assembly from the recoil assembly, the pressure from the explosion causes cylinder '64 to be separated from the projectile assembly as described above. This substantially reduces the length of the imbedded projectile assembly thereby enhancing the subsequent orienting or keying of the projectile assembly. 7

After the cylinder 64 is separated from the projectile assembly 12, the cable 58 is tensioned whereby the projectile assembly 12, due to the positioning of the cable attachment on the exterior of the tube 46, is moved from a substantially vertical position to a substantial horizontal position parallel with the bottom, as shown in FIG. 8. This latter position firmly imbeds the projectile assembly in the bottom thereby firmly anchoring the vessel.

The separated recoil assembly 14 is recoverable by taking in cable 36, whereby the same may be subsequently reused.

It will thus be seen that there has been provided a simply constructed imbedment anchor wherein a major portion thereof is recoverable subsequent to the imbedment of the projectile assembly forming part of the anchor. As will be apparent, this partial recovery significantly reduces the cost of each anchor assembly. Further, there has been provided novel means for further separating the remaining components after imbedment. leaving only the projectile assembly, thereby enhancing the keying of the projectile assembly for maximum holding power. The novel imbedment anchor of the invention is further provided with safety features which prevent premature ignition thereof before the anchor has reached a predetermined water depth.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated inany of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. 'An imbedment anchor comprising a projectile assembly including an anchor body having leading and trailing ends and a separable body extension secured to and extending rearwardly from the trailing end of said anchor body, a recoil assembly mated with said body extension and separable therefrom, the projectile assembly and recoil assembly normally being in such assembled relation, a first cable extending from said anchor body, a second cable extending from said recoil assembly for recovering the same, means for forcibly separating said recoil assembly from said projectile assembly to propel the latter from the former for imbedment of the anchor body and thereafter forcibly separating said body extension from said anchor body.

2. The combination of claim 1 wherein said body extension is cylindrical and fitted within the recoil assembly in the normal assembled condition of the anchor.

3. The combination of claim 1 wherein the recoil assembly includes a laterally enlarged reaction section, and there are shear connections between such enlarged reaction section and the anchor body, these connections being broken when said projectile and recoil assemblies are forcibly separated.

4. An imbedment anchor comprising a projectile assembly including an anchor body having leading and trailing ends and a separable body extension secured to and extending rearwardly from the trailing end of said anchor body, a recoil assembly mated with said body extension, the projectile assembly and recoil assembly normally being in such assembled relation, propulsion means for providing force acting between said projectile and recoil assemblies to propel the former from the latter for imbedment of the anchor body, means including the propulsion means for forcibly separating said body extension from said anchor body upon operation of the propulsion means tending to separate the projectile assembly and the recoil assembly, said propulsion means comprising an explosive charge, a portion of the expanding gases produced upon detonation of said charge being employed to produce separation of the body extension from the anchor body, said anchor body and body extension being joined by means forming a secondary chamber therebetween to receive said portion of the expanding gases upon detonation of the explosive charge, the gases in the secondaiy chamber producing separation of the body extension from the anchor body subsequent to initiation of the propulsion of the projectile assembly from the recoil assembly.

References Cited in the file of this patent UNITED STATES PATENTS 2,583,965 Page et al Jan. 29, 1952 2,961,955 Macdonald Nov. 29, 1960 3,032,000 Feiler May 1, 1962 3,036,542 Robinson May 29, 1962

Claims

1. IN IMBEDMENT ANCHOR COMPRISING A PROJECTILE ASSEMBLY INCLUDING AN ANCHOR BODY HAVING LEADING AND TRAILING ENDS AND A SEPARABLE BODY EXTENSION SECURED TO AND EXTENDING REARWARDLY FROM THE TRAILING END OF SAID ANCHOR BODY, A RECOIL ASSEMBLY MATED WITH SAID BODY EXTENSION AND SEPARABLE THEREFROM, THE PROJECTILE ASSSEMBLY AND RECOIL ASSEMBLY NORMALLY BEING IN SUCH ASSEMBLED RELATION, A FIRST CABLE EXTENDING FROM SAID ANCHOR BODY, A SECOND CABLE EXTENDING FROM SAID RECOIL ASSEMBLY FOR RECOVERING THE SAME, MEANS FOR FORCIBLY SEPARATING SAID RECOIL ASSEMBLY FROM SAID PROJECTILE ASSEMBLY TO PROPEL THE LATTER FROM THE FORMER FOR IMBEDMENT OF THE ANCHOR BODY AND THEREAFTER FORCIBLY SEPARATING SAID BODY EXTENSION FROM SAID ANCHOR BODY.