US3370566A

US3370566A - Embedment device

Info

Publication number: US3370566A
Application number: US464766A
Authority: US
Inventors: John A Dorr; Owen Wadsworth
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1965-06-17
Filing date: 1965-06-17
Publication date: 1968-02-27
Anticipated expiration: 1985-02-27
Also published as: GB1094438A

Description

J. A. DORR ET AL Feb. 27, 1968 EMBEDMENT DEVICE 3 Sheets-Sheet 1 Filed June 17, 1965 FIG-I- PRIOR ART INVENTORS WITNESSES John A. Dorr 8 Wadsworth Owen BY ATTORNEY Feb. 27, 1968 Filed June 17, 1965' V Fle zA.

J. A. DORR ET AL 3,370,566

EMBEDMENT DEVI CE 5 Sheets-Sheet 2 Feb. 27, 1968 J DORR ET AL 3,370,566 7 EMBEDMENT DEVICE F i led June 17, 1965 3 Sheets-Sheet United States Patent 3,370,565 EMEEDMENT DEVICE John A. Dorr and Wadsworth Owen, Baltimore, Md., assignors to Westinghouse Electric Corporation, Pittsburgh, 1 2., a corporation of Pennsylvania Filed June 17, 1965, Ser. No. 464,766 15 Claims. (Cl. 114-206) This invention in general relates to embedment devices, and particularly to an embedment device for use as an anchor or with slight modification, as a core sampler for obtaining samples for use in geological studies.

A need has existed for a lightweight anchor for water craft, self-sufiicient oceanographic telemetry stations, marker buoys, and the like. One type of anchor which has an extremely high holding force and is lightweight utilizes an explosive charge to drive the anchor into the bottom sediment. The explosive anchor principle is also applicable to core samplers. Although the explosive anchor can be both lightweight and have a high holding force, there are tactical situations where an explosive report would be highly undesirable. The biggest objection to the explosive anchor, however, is the necessity of handling explosives on board ship.

Another type of device which eliminated the need for explosives, operated on the principle of allowing water pressure to drive a core tube into the ocean bottom. As is apparent, core samplers and anchors are very similar, and in fact an anchor may be a core sampler with fiukes. The core sampler was provided with a piston which kept the water out of a chamber until the piston was released, whereupon the water pressed downwardly upon the piston forcing a core sampler connected to the piston, into the ocean bed. This device in actuality proved to be less suflicient than theoretically imagined. Reaction forces of the moving piston and core tube tended to drive the apparatus away from the ocean bottom as much as it tended to drive it into the ocean bottom. This apparatus will be discussed in more detail with respect to FIG. 1.

It is therefore a primary object of the present invention to provide a lightweight anchor or core sampler which is driven firmly into the bed of a body of water.

Another object is to provide an anchor which has a high holding force in relation to its weight.

Another object is to provide an underwater embedment device which utilizes the pressure of the surrounding water as a positive driving force.

Another object is to provide an underwater embedment device which is relatively simple to manufacture.

Briefly, in accordance with the above objects, there is provided an embedment device in the form of an elongated hollow member being closed at one end. A closure means is provided in order to keep the pressure within the hollow member at a certain value. That is, as the embedment device descends through the water and just prior to hitting the ocean bottom, the surrounding water medium is substantially kept out of the inside of the hollow member. The closure means, in essence, acts to maintain a pressure differential between the inside and the outside of the member. Upon striking the ocean bed, an actuator means displaces the closure means and the existing pressure differential forces the bottom sediment into the hollow member and conversely, the hollow member into the bottom sediment. In a preferred embodiment of the invention, the hollow member is closed by means of a piston at its lower end.

Flukes pivotally attached to the elongated hollow member will retain the member within the sediment against a pull by a buoy or surface craft connected to the embedmerit device by a long cable. Without the flukes, the embedment device serves as a core sampler.

For a majority of uses the embedment device may be thrown overboard with the inside of the device being at atmospheric pressure. As the device descends through the water, the pressure differential between the inside and outside of the device will increase with increasing depth until the device strikes the bottom to allow the pressure differential to force the device into the sediment. For operation where extreme depths are encountered, the device may be pressurized to a value greater than atmospheric pressure so that the device is not crushed by the tremendous pressures encountered at the deep depths. It is only necessary to maintain a pressure differential. Conversely, where very-shallow depths are encountered, the device may be evacuated to a pressure less than atmospheric so that a relatively high pressure differential exists just prior to striking the bottom at these relatively shallow depths.

The above stated as Well as further objects, advantages and uses will become apparent upon a reading of the following detailed specification taken in conjunction with the drawings, in which:

FIGURE 1 illustrates a core sampler of the prior art;

FIG. 2A illustrates an embodiment of the present invention in the form of an anchor;

FIG. 28 illustrates an embodiment of the present invention utilized as a core sampling device;

FIG. 3 illustrates the anchor of FIG. 2A in an embedment position;

FIG. 4 illustrates, in more detail, a closure means for use in the embodiments of FIGS. 2A and 2B; and

FIG. 5 illustrates another type of closure means which may be utilized in the present invention.

The embedment device of FIG. 1 is a prior art device which attempts to utilize the water pressure at the ocean bed for driving a water tube into the ocean bed to extract samples. The ernbedrnent device includes a main cylinder 19 which is lowered by means of cable 12, through the water until the cylinder supports 15 rest on the ocean bed 16. A piston 18 to which a core tube 20 is attached, is located within the cylinder it) and is free to move up and down within the cylinder 10. The piston, however, is constrained against movement by means of a holding mechanism 22 which is releasable by pulling a wire 23 from a surface ship.

Prior to lowering, the inside of the chamber 10 is at atmospheric pressure. After the device is lowered and is resting on the ocean bed as illustrated in FIG 1, the pressure within the cylinder 19 is still at atmospheric pressure while the surrounding water medium is at a much greater pressure. The piston 18 prevents the surrounding water from entering the cylinder at the upper end and suitable packing means (not shown) around the core tube 29 at the lower end of the cylinder prevents water from entering at the lower end.

The holding mechanism 22 is released by activation from aboard ship through the wire 23 so that the piston 18 is no longer constrained. The water pressure acting on top of the piston 18 is much greater than the pressure acting on the bottom of the piston 18 (since the pressure within the cylinder 10 is at atmospheric pressure) and the piston and core tube 20 are forced into the ocean bed 16 by means of the water pressure. If the device of FIG. 1 were of great weight or if the cylinder support 15 could be securely fastened to the ocean bed 16, the water pressure would efiiciently drive the core tube into the ocean bed 16. The device, however, is not of a sufiicient weight, and it is highly impractical to secure the support to the ocean 'bed, and consequently the device does not operate as theoretically expected. This is due to the fact that upon actuation of the holding mechanism the piston and core tube 20 is driven downwardly by the water pressure. The reaction force,

however, of the piston and core tube 2% is of such high value as to tend to push the device away from the ocean bed so that the net result would probably be just as ineflicient as a free falling core tube. In order to effectively combat these reaction forces, there is provided a wide flange member 27 which, in essence, pushes against the water above it when the piston 18 is released. Although the flange member 27 aids somewhat in the operation, it is not enough to make a really efficient device, and moreover adds unnecessary weight and bulk to the embedment device.

FIG. 2A illustrates an embodiment of the present in vention. The embedment device 30 comprises an elongated hollow member 32 which is closed at the upper end and has a closure means 34 at the lower end for keeping water out of chamber 35 as the device 30 descends through the water towards the ocean bottom. An eyelet member 37 of the device 30 may be connected with a cable for lowering purposes. In the embodiment of the invention illustrated in FIG. 2A, a plunger 40 strikes the ocean bed first, causing a displacement of the closure means 34 as will be illustrated in FIG. 4. If the chamber 35 is at atmospheric pressure, the pressure differential between the inside and outside of the device is sufficient to force bottom sediment into the chamber 35 after the plunger 40 strikes the ocean bottom. Although the words ocean and ocean bottom are used herein, it is understood that any fiuid medium and any bed of the fluid medium or solid-fluid interface is intended. The anchor of FIG 2A includes a pair of fiukes 4.3 and 44 which are pivotally attached to the elongated hollow member 32 at points 45 and 4-6. A second pair of fiukes at right angles to fiukes 43 and 44 may be provided in order to offer a greater holding force. One of these flukes 48 is illustrated and other fluke of the second pair would be behind the member 32.

Basically, the device 30 incorporates an elongated hollow member 32. A specific form of elongated hollow member is illustrated by way of example in FIG. 2A and includes a core tube or first cylindrical portion 50 and a second cylindrical portion 53 having a greater width than the first cylindrical portion 50. Without increasing the length, and without significantly affecting the hydrodynamic properties of the device 30, the larger portion 53 provides added space in which sediment material may enter, and provides added potential energy to permit greater penetration.

FIG. 2B is an embedment device similar to that described in FIG. 2A but without the fluke members. The core sampler 56 operates on the identical differential pressure concept described with respect to FIG. 2A and serves as an execellent core sampler for removing a core of bottom sediment for geological study purposes.

FIG. 3 illustrates the anchor of FIG. 2A after a descent and embedment. As was stated, after the closure means is displaced by means of the p1unger'40 striking the ocean bottom or bed 59, the difference in pressure between the inside and outside of the anchor 30 forces the device into the sediment and the sediment into the tube portion 50. An upward pull on the cable 61 will force the pivotally mounted

fluke members

43, 44 and 48 to an outward position. FIG. 3, therefore, i1- lustrates the situation when the embedment device has entered the ocean bottom and has subsequently been pulled up to displace the fluke members. The holding strength of the anchor depends upon various factors. Included as factors is the weight of the anchor itself. Also to be considered is the adhesion of the anchor to the sediment, the shearing strength of the sediment and the weight of the sediment above the open flukes. The design of the fluke members may be varied in order to obtain anchors with different holding strengths.

FIG. 4 illustrates a closure means 34 in more detail. Bearing in mind that the function of the closure means is to maintain a pressure differential between the inside of which utilizes a piston member 65 located within the core tube 50. The piston 65 acts as a seal to keep the water out of the chamber 35 (FIG. 2A) during a descent in the water toward the ocean bottom. The lower end of core tube 50 is threaded for receiving a threaded sleeve 68, modified asillustrated in FIG. 4 to include a beveled portion and a beveled portion 71. The beveled portion 71 forms a sharp angle with the lower portion of the threaded sleeve 68 to aid in a penetration of the ocean bottom.

The lower end of the core tube 50 is beveled at 73. The

beveled portions

73 and 70 together form a ridge for receiving

pins

75 and 76 which extend through suitable holes in the piston 65. The other ends of the

pins

75 and 76 extend into chamber 79. The plunger 40 com prises a rodlike portion 81 connected to a larger diameter cylindrical portion 83. The

pins

75 and 76 abut the cylindrical portion 83 of the plunger and are constrained against movement. (Although only two

pins

75 and 76 are illustrated, more could be utilized.) With the

pins

75 and 76 constrained against movement, any external water pressure tending to force the piston up into the 7 core tube 51) is prevented from doing so. .O-

rings

85 and 86 aid in maintaining a water tight seal.

In operation, the embedment device is thrown overboard and descends through the water towards the ocean bottom. As the embedment device decreases in depth,

' striking the ocean bottom. The plunger 40 strikes the ocean bottom first because it is extended away from the lower end of the embedment device, and is forced upward into the recess 79. As soon as the cylindrical portion 83 of the plunger 40 moves out of the way of the

pins

75 and 76, the smaller diameter of the rod portion 81 is presented, and the

pins

75 and 76 are free to move inwardly and in fact are forced inwardly by the forces acting on the bottom of the piston and transmitted to the

beveled edges

70 and 73. After the

pins

75 and 76 have been moved inwardly, the piston 65 is free to travel within the core tube 50. The threaded sleeve 68 begins its penetration of the sediment and the aforementioned pressure differential causes the piston 65 and underlying sediment to be drawn into the core tube 50 by suction and consequently, the embedment device is pushed down into-the bottom sediment. In other words, there is an initial resultant downward force that is equal to the product of the throat area and the differential pressure in the throat area of the core tube 50.

Closure means using seals other than a piston member,

such as 65, may also be used. Such seals include for example, valve mechanisms which may be activated upon a striking of the ocean bed, frangible seals such as glass or plastic which may be broken upon impact with the ocean bottom, and rupturable diaphragms, to name a few, The preferred embodiment of the invention herein illustrates the piston member because the piston in effect is a plug which is forced up the core tube 50 ahead of bottom sediment and any small amount of water which may precede the bottom sediment. The plug in essence keeps the water out of the chamber 35. If a diaphragm or the like were utilized and water did enter the chamber, there would tend to be a free expansion of water vapor which would increase the pressure within the chamber 35 and consequently decrease the pressure differential previously built up. The pins, plunger and beveled edges arrangement of FIG. 4 is illustrative of one retaining means for preventing movement of the piston. A somewhat modified arrangement is illustrated in more detail in FIG. 5.

The operation of the embodiment of FIG. 5 is similar to that of FIG. 4; that is, when the embedment device hits the ocean bottom the previously restrained piston member will be free to move up the core tube. The piston member in FIG. 5 is located in the vicinity of the lower end of core tube 92. The lower end of core tube 92 has apertures for receiving restraining means in the form of

ball bearings

94 and 95 which nestle in the detents or grooves 97 and 97' within the piston 90. Slidably mounted on the outside of the core tube 92 is a sleeve member 109 which has an

inside surface

102 and 102 contacting the

ball bearings

94 and 95 respectively. A lower section of the sleeve is out of contact with the core tube 92 so as to form a

free space

104 and 104.

During a descent in the water towards the ocean bottom, water pressure acts on the bottom of the piston 90 tending to force it up into core tube 92. The movement of the piston is restrained due to the fact that the forces at

surfaces

107 and 107 tending to force the

ball bearings

94 and 95 outwardly are counteracted by the forces at

surfaces

102 and 102. As long as surfaces 102 and 102' contact the

ball bearings

94 and 95, the piston 90 cannot get past the ball bearings and will remain in its initial position even against increasing water pressures. When the embedment device hits the ocean bottom, the sleeve member 100 extending beyond the core tube 92, will impact first and since it is slidably mounted on the core tube will be forced upwardly thereby bringing surfaces 102 and 102' out of contact with the

ball bearings

94 and 95 respectively. As the tube 100 is forced upwardly, the lower portion which is out of contact with the core tube 92 becomes positioned opposite the

ball bearings

94 and 95 so that surfaces 192 and 102' no longer constrain the outward movement of the ball bearings. Consequently, the forces acting on the piston operate to push the

ball bearings

94 and 95 aside so that the piston 90 is free to move up the core tube 92 ahead of the bottom sediment. O-rings 110 and 111 aid keeping the surrounding water out of the chamber of the embedment device.

Although the present invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example and that numerous modifications are made possible in light of the teachings herein.

What is claimed is:

1. An underwater embedment device comprising:

(a) an elongated hollow member closed at one end thereof;

(b) closure means for keeping the pressure within said hollow member at a predetermined value;

(c) actuator means movable relative to said closure means for displacing said closure means upon *striking the bottom of a body of water, for permitting bottom sediment to enter said hollow member; and

(d) the predetermined value of said pressure being less than the pressure of the surrounding water medium just prior to striking said bottom.

2. An underwater anchor device comprising:

(a) an elongated hollow member closed at one end thereof;

(c) actuator means for displacing said closure means upon striking the bottom of a body of water, for permitting bottom sediment to enter said hollow member;

(d) fiuke means pivotally connected to said elongated hollow member; and

(e) the predetermined value of said pressure being less than the pressure of the surrounding water medium just prior to striking said bottom.

3. An underwater embedrnent device comprising:

(a) an elongated hollow member closed at the upper end thereof;

(b) closure means closing the lower end thereof for keeping the pressure within said hollow member at a predetermined value;

(c) actuator means movable relative to said closure means for displacing said closure means upon engagement with the bottom of a body of water for permitting bottom sediment to enter said hollow member and (d) the predetermined value of said pressure being less than the pressure of the surrounding water medium just prior to striking said bottom.

4. An underwater embedment device comprising:

(a) an elongated hollow member closed at the upper end thereof;

(b) a piston arranged within said member at the lower end thereof for preventing Water from entering said member during a descent in the water;

(0) means movable relative to said piston means for displacing said piston when said embedment device strikes the bottom of a body of water for permitting bottom sediment to enter said hollow member; and

((1) said piston maintaining the pressure Within said member constant, at a value less than the pressure of the surrounding water medium just prior to striking said bottom.

5. An anchor comprising:

(a) an elongated hollow member closed at the upper end thereof;

(c) means for displacing said piston when said embedment device strikes the bottom of a body of Water for permitting bottom sediment to enter said hollow member;

(d) a pair of fiukes pivotally connected to said elongated hollow member; and

(e) said piston maintaining the pressure within said member constant, at a value less than the pressure of the surrounding water medium just prior to striking said bottom.

6. An underwater embedment device comprising:

(a) an elongated hollow member closed at the upper end thereof;

(b) sealing means for establishing a pressure diiferential between the inside of said member and the surrounding water prior to striking the bottom of a body of Water;

(c) means movable relative to said sealing means for displacing said sealing means when said embedment device strikes the bottom for allowing said pressure differential to force said device into the bottom sediment; and

((1) said sealing means maintaining the pressure within said device constant, at a value less than the pressure of the surrounding water medium just prior to striking said bottom.

7. An underwater embedment device comprising:

(a) an elongated hollow member having a cylindrical tube portion;

(b) said hollow member being closed at one end thereof;

(c) sealing means within said cylindrical tube portion for maintaining a pressure differential between the inside of said hollow member and the surrounding water medium, upon a descent in the water;

((1) actuator means movable relative to said sealing means for displacing said sealing means into said hollow member, within said cylindrical tube portion, when said device strikes the bed of a body of water; and

(c) said sealing means maintaining the pressure within said device constant, at a value less than the pressure of the surrounding water medium just prior to striking said bed.

8. An underwater embedment device comprising:

(a) an elongated hollow member closed at the upper end thereof;

(b) piston means located in said hollow member at the lower end thereof;

(c) retaining means for preventing movement of said piston means;

((1) an actuator means movable relative to said piston means for releasing said retaining means when said actuator means strikes the bed of a body of water, thereby allowing bottom sediment to enter said hollow member.

9. An anchor comprising:

(a) an elongated hollow member closed at the upper end thereof; 7

(b) piston means located in said hollow member at the lower end thereof;

(c) retaining means for preventing movement of said piston means;

(d) 'a movable actuator means for releasing said retaining means when said actuator means strikes the bed of a body of water, thereby allowing bottom sediment to enter said hollow member;

(e) fluke means pivotally connected to said elongated hollow member.

10. An underwater embedment device comprising:

(a) an elongated hollow member closed at the upper end thereof;

(b) sealing means for preventing water from entering said member during a descent in the water;

() a plunger movable relative to said sealing means extending beyond the lower end of said hollow member for displacing said sealing means, when said plunger strikes the bed of a body of water.

11. An embedment device comprising:

(a) a first elongated cylinder;

(b) a second cylinder connected to said first cylinder and having a greater width than said first cylinder, said second cylinder being closed at its unconnected end;

(c) said first and second cylinders defining a hollow chamber;

(d) closure means in the vicinity of the unconnected end of said first cylinder for maintaining the pressure within said hollow chamber at a predetermined value;

(e) means for displacing said closure means upon impact of said embedment device with a solid material; and

(f) the predetermined value of said pressure being less than the pressure of the surrounding water medium just prior to said impact.

12. An anchor comprising:

(a) a first elongated cylinder;

(g) the predetermined value of said pressure being less' than the pressure of the surrounding water medium just prior to said impact. 13. An anchor according to claim 12 which includes two pair of flukes pivotally connected to the first elongated 2Q cylinder.

14. An underwater embedment device comprising: (a) an elongated hollow member closed at the upper end thereof; I (b) a sleeve member slidably mounted on said hollow member and having a portion on the inside of said sleeve normally out of contact with said hollow member; (c) a piston located in the vicinity of the lower end of said hollow member, and having a detent portion therein;

(d) restraining means extending through apertures in the lower end of said member and contacting said detent portion and said sleeve member to prevent movement of said piston whereby when said embedment device strikes the bottom of a body of water said sleeve will move relative to said hollow member to allow said restraining means to move to said portion on the inside of said sleeve normally out of contact with said hollow member. 15. An underwater embedment device according to claim 14 wherein the restraining means comprises at least one ball bearing.

References Cited UNITED STATES PATENTS 1,758,911 5/1930 Hamilton 114-206 3,118,417 1/1964 Stanwick 114-206 3,263,641 8/1966 Stimson 114-206 1,803,731 5/1931 Scott 175245 2,288,210 6/ 1942 Schlumberger 175-245 2,664,269 12/1953 Knight et al 175245 X 3,279,547 10/1966 Berne et al. 175--6 FOREIGN PATENTS 229,5 6 3 2/ 1925 Great Britain.

MILTON BUCHLER, Primary Examiner.

T. M. BLIX, Assistant Examiner.

Claims

1. AN UNDERWATER EMBEDMENT DEVICE COMPRISING: (A) AN ELONGATED HOLLOW MEMBER CLOSED AT ONE END THEREOF; (B) CLOSURE MEANS FOR KEEPING THE PRESSURE WITHIN SAID HOLLOW MEMBER AT A PREDETERMINED VALUE; (C) ACTUATOR MEANS MOVABLE RELATIVE TO SAID CLOSURE MEANS FOR DISPLACING SAID CLOSURE MEANS UPON STRIKING THE BOTTOM OF A BODY OF WATER, FOR PERMITTING BOTTOM SEDIMENT TO ENTER SAID HOLLOW MEMBER; AND (D) THE PREDETERMINED VALUE OF SAID PRESSURE BEING LESS THAN THE PRESSURE OF THE SURROUNDING WATER MEDIUM JUST PRIOR TO STRIKING SAID BOTTOM.