US2999572A - Earth anchor - Google Patents

Description

Sept. 12, 1961 J. D. HlNCKLEY EARTH ANCHOR 2 Sheets-Sheet 1 Filed Feb. 12, 1958 INVENTOR JOHN D. Hl/VG/(LEY MQM, Mu VW ATTORNEY- Sept. 12, 1961 Filed Feb. 12, 1958 [6 V g 15 /a I F /7 .J. D. HINCKLEY EARTH ANCHOR 2 Sheets-Sheet 2 INVENTOR JOHN D. Hl/VC/(LEY W M; 9M

ATTORNEYS llnited States Patent 2,999,572 EARTH ANCHOR John D. Hmckley, 2112 Octavia St., New OrleanslS, La. Filed Feb. 12, 1958, Ser. No. 714,741 2 Claims. (Cl. 189-91) The present invention relates to marine earth anchors and more particularly to an integral motor-driven screw anchor designed to bore into submerged earth in underwater operations. Specifically the anchor is intended to function as a fixed base for cables and the like which guy superstructures of the type employed in off-shore drilling operations and for mooring floating vessels.

One of the objects of the invention is to provide motor-driven mechanism for rotating and driving a screw type anchor which bores into the submerged bed of a body of water and thereby anchors itself firmly into the subterranean earth.

Another object of the invention is the provision of means to permit rotation of the anchor screw in one direction only, which means acts as a brake to prevent rotation of the anchor in the opposite direction.

A further object of the invention is to provide a screw with eccentric vertical surfaces at the large end which compact the displaced earth to the periphery and thus make a hole or path for the anchor body to follow.

A further object of the invention is to provide swivel connections between the anchor screw and the motor for rotating the screw, as well as between the motor and the guy cable to which it is attached.

Other objects will be apparent from the following description of a preferred embodiment of the apparatus forming the invention when taken with the accompanying drawings in which FIG. 1 is an elevation of the anchor;

FIG. 2 is a section taken on line 2-2 of FIG. 1;

FIG. 3 is a section taken on line 3-3 of FIG. 1;

FIG. 4 is a vertical section, partly broken, taken on line 4-4 of FIG. 1;

FIGS. 5 and 6 are diagrammatic views of two stages of the manner in which the anchor is lowered from a floating barge or the like and embedded in the submerged soil of a body of water;

FIGS. 7 and 8 illustrate the manner in which the motor reverses the rotation of the anchor and the means for braking the anchor screw; and

FIG. 9 shows the anchor embedded at an angle to the earth bottom, the cable being connected to a structure or a mooring for floating vessels.

In the drawings, the anchor body 10 comprises a mo tor cylinder portion 11 and a reciprocable piston 12, there being passages 13, 14 for fluid under pressure supplied alternately to the upper and under sides of the piston. Suitable hose connections 15, 16 controlled by a valve (not shown) communicate with passages 13, 14, respectively. It will be noted that the anchor body 10 is provided with an enlarged portion 10 swiveled to a head 17 to which guy cable 18 is secured. Annular passages 19, 20 in head 17 permit communication between the supply hoses and the fluid passages in the cylinder when the cylinder and head are rotated relative to each other.

Piston rod 21 is provided at its lower end with a T head 22 disposed in a recess 23 in the upper end of shaft 24, the latter being integral with or otherwise secured to a conical screw anchor 25. Head 22 is held to shaft 24 by a collar 26 threaded to the shaft so that the piston has a swivel connection with the shaft. The up per end of shaft 24 is provided with helical ribs 27 cooperating with helical grooves 28 in the walls of the lower end of the anchor body to provide for relative rotary oscillation between the anchor body and the anchor screw "ice when the piston is reciprocated. Longitudinal grooves 29 in the ribs permit flow of fluid from above the ribs on the upstroke of the piston and conversely on the downstroke.

It will be seen that the upper end of the anchor screw is formed to provide two peripheral surfaces which are eccentric to the shaft 24, the purpose of which is to compact displaced earth as the screw advances. The anchor screw is provided with helical lateral boring flanges 30 terminating adjacent to the pointed end 31 of the anchor screw. It will also be noted that apertures 32 near the lower end of the anchor screw are in communication with a supply line 33 through which fluid under pressure is supplied to the apertures to direct jet screams into the earth bed when the anchor reaches this bed in the initial stage of the boring operation. These jet streams form a depression into which the anchor, by its own weight, positions itself prior to rotation thereof by the motor. The anchor is permitted to remain idle for a short period of time after jetting in what might be called a setting stage.

In FIGS. 1, 2 and 4, the anchor body is shown as having a plurality of pairs of spaced cars 34 forming journals for pivoted flaps 35, the ears and flaps being angularly disposed as illustrated for a purpose to be: described hereinafter. It will also be observed that at diametrically opposite sides of the anchor screw there are pivoted arms 36 having limited pivotal movement about pins 37.

These arms are designed to provide a braking effect against reverse rotary motion of the anchor screw as will be later explained.

In operation the anchor and the guy cable to which it is attached are lowered from a boom 38 on a floating barge 39 on the surface of the water W above the desired location. It is to be understood that a number of cables 18 are to be anchored at points preferably spaced equidistantly from the base of a vertical skeleton tower resting on the submerged earth E, the tower projecting to some height above the surface of the water and being guyed by the cables after the latter have been firmly anchored. When the anchor has touched bottom, a stream of water under pressure is forced from the jet openings 32 at the lower end of the anchor screw to release some of the earth, the anchor settling in the depression thus formed. The anchor is then permitted to remain idle briefly without jetting, during which time soil repacks around and on top of the anchor. Compressed air, gas, or liquid is then admitted to the upper end of the motor cylinder through passage 13 to force the piston 12 downwardly. At the same time fluid is exhausted from the under side of the piston through passage 14. The cooperating helical ribs 27 on the anchor shaft and grooves 28 in the motor body cause the anchor to rotate in a counterclockwise direction as it bores into the soil. The reaction of the anchor body to move upwardly and rotate clockwise causes the pivoted flaps 35 to open outwardly from the anchor body, as shown in FIG. 7, to resist this upward movement of the body. Said flaps are designed to stop against the anchor body at the horizontal position when fully opened. When the anchor with its screw is rotating counterclockwise, as in FIG. 3, the brake arms 36 move to the positions indicated in full lines in this figure and offer little or no resistance to rotation of the anchor. Hence, the anchor bores into the soil during this stage of operation.

When the piston 12 has reached the end of its downstroke, the supply of compressed air or fluid is transferred to the lower end of the cylinder to force the piston in the opposite direction, that is, in an upward direction with respect to the anchor body 10. At this time the brake arms 36 move outwardly and resist rotation of the screw anchor in a clockwise direction. Flaps 35 fold ingen er-a Wardly as the motor body rotates in a counterclockwise direction, as seen in FIG. 8, the body falling to hammer on the anchor. These alternate strokes of the piston are repeated until the anchorhas advanced into the soil the required depth necessary to firmly hold it in position. Depending on the angle at which the guy cable is to be disposed with respect to the tower, the anchor may be tilted as shown in FIG. 9 by pulling on the cable after the initial setting and boring steps. This is followed by further reciprocations of the piston to permit additional penetration of the soil.

The anchor described herein is relatively inexpensive, is'self-boring and is expendable. It is not intended that itbe recovered once it is embedded in the bed of the ocean or other body of water.

A preferred embodiment of the invention has been illustrated and described, but it is evident that modifications are contemplated within the scope thereofas de fined in the appended claims.

What is claimed is:

1. An anchor of the class described comprising a rotatable conical boring element having lateral helical said ensaasalale ith. e matsrifl bein acted for resisting rotation of the element in the opposite direction, said pivoted means being movable out of engagement with said material and disposed in substantially tangential relation to said element when the element is rotated in said'one direction and freely swingable outwardly from said element into penetrating engagement with said material. when the element tends to rotate in the opposite'direction, thereby to resist rotation of said element in said oppositev direction, and a plurality of flaps pivoted to said cylinder element, said flaps being sWingablef rom a position wherein they lie against the cylinder element to a postion in which they project radially outwardly, the faces of said flaps being inclined with respect to the axis of said cylinder element.

2. An anchor as defined in claim 1 in which said flaps swing toward said cylinder element and away from said boring element when said pivoted means on the boring elementproject radially, said flaps swinging to a radial position during rotation of said boring element in said one direction, the inclination of said flap faces being such that axial movement of said cylinder element in a direction away from said boring element is resisted.

References Cited in the file of this patent UNITED STATES PATENTS 1,133,295 Layne et a1. Mar. 30, 1915 1,455,163 Blackburn May 15, 1923 1,828,604 Humphreys Oct. 20, 1931 2,002,386 Bannister May 21, 1935 2,013,070 Sheridan Sept. 3, 1935 2,603,319 Dyche July 15, 1952

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