United States Patent 2357368

This invention relates to anchors of the type that can be quickly set into and removed from the ground, and is particularly useful for military uses, such as the mooring of aircraft on the ground. The present invention is a modification of the anchor disclosed in my application Serial No....

Warren, Walter F.
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52/157, 52/161
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This invention relates to anchors of the type that can be quickly set into and removed from the ground, and is particularly useful for military uses, such as the mooring of aircraft on the ground.

The present invention is a modification of the anchor disclosed in my application Serial No. 420,391, filed November 25, 1941.

An object of the present invention is to provide an anchor structure that is simple and rugged and reliable in service.

A more specific object is to provide a screw type anchor having expansible flukes adapted to be expanded and retracted in response to relative rotation of a fluke-setting member at the upper end of the anchor, in which a particularly simple construction is employed for facilitating selective rotation either of the anchor as a whole to screw it into the ground, or the fluke-setting member only for setting or retracting the flukes.

Still another object is to provide an anchor with ample strength and long life that is relatively simple to construct.

Other more specific objects and features of the invention will become apparent from the following detailed description which refers to the drawing of a particular embodiment of the invention.

Briefly, the anchor in accordance with the present invention consists of a tubular member having a screw thereon, whereby it may be forced into the ground by rotation and having flukes which are contained within the body of the tubular member while the latter is being screwed into the ground, but are forced out into solid ground that has been undisturbed by the screw after the member has been set to the desired depth. Such devicestre broadly old and the present invention resides in details that result in a more rugged, simple and reliable device.

One such detail is a simple and mechanically strong structure for expanding and retracting the flukes.

Another detail is a simple, but effective, combination of a bail on the housing of the anchor and a turning member for expanding the flukes with a handle, whereby torque may be applied either to the housing to screw the anchor into the ground, or to the fluke-expanding member alone to expand or retract the flukes.

Other features involved in the invention will become apparent from the detailed description that refers to the drawing, in which Fig. 1 is an elevation view of my anchor shown fully set in the ground with its flukes expanded; Fig. 2 is a longitudinal section through the anchor with the flukes contracted; Fig. 3 is a cross section in the plane III-III of Fig. 2; Fig. 4 is a detail longitudinal section through the lower part of the anchor, taken at right angles to the section of Fig. 2; and Fig. 5 is an elevation view with parts broken away of a coring tool for making a hole in which to install the anchor.

Referring first to Fig. 1, the anchor therein disclosed comprises as its main external elements a tubular housing 10 terminating at its lower end in a point II and having a screw flange 12 positioned a short distance above the point 11. The housing 10 is surmounted by a cap 13 having an eye 14 therein for receiving a cross bar 15 for turning it. There is secured to the housing 10, just below the cap 13, a reinforcing collar 16 to which is hinged a bail 7. In use, an anchor line 18 may be attached to the bail 17 and extended to the object to be anchored.

Referring to Fig. 2 the main portion of the housing 10 consists of a tube or sleeve 19 to the lower end of which there is attached a casting 20 having the screw flange 12 formed integral therewith. The casting 20 may be internally threaded at its upper end for joinder to the externally threaded lower end of the sleeve 19. After the parts are screwed together they may be welded, as indicated at 21. The casting 20 has an internal bore alighed with the internal bore of the sleeve 19 for guidingly supporting a carriage block 22 which cooperates with a pair of flukes 23 and 24 which are adapted to extend through opposite openings 25 and 26 in the casting 20 below the screw flange 12 thereon. Each of the flukes comprises a flat plate portion 27 having a chisel edge 28 at its free end and having a reinforcing rib 29 extending along its upper side and terminating in a hinge lug 40. The two hinge lugs .40 are positioned alongside each other within a slot in the lower end of the carriage block 22, and are pivotally secured to the block by a pin 30.

When the flukes 23 and 24 are fully retracted, as shown in Fig. 2 (at which time the carriage block 22 is in extreme upper position), the beveled lower ends 28 of the flukes form continuations of the point II and the flukes substantially fill and close the recesses or openings 26 through which they are adapted to be projected, to thereby prevent, as much as possible, the entry of soil into the housing.

The flukes are expanded into the holding position shown in Fig. 1 by forcing the carriage block 22 downwardly within the casting 20 by a rod 32 which is threaded into the block 22 and locked with a taper pin 33. The rod 32 extends upwardly through the sleeve 19 and may be provided with flanges 34 at intervals therealong, which are slidable within the sleeve 19 to prevent buckling of the rod 32 when it is in compression. The upper end of the rod is provided with screw threads 35 engaged by a nut member 36 rotatable in the sleeve 19. The nut member 36 has finer threads at the extreme upper end of its bore, whereby it is joined to a threaded stem 37, the head of which constitutes the cap 13. To prevent the entry of dirt into the mechanism at the upper end, the cap 13 is preferably provided with an annular groove 38 which receives the upper end of the sleeve 19, thereby providing an effective seal. The stem 37 is preferably locked to the nut member 36 by a taper pin 39 so that the nut member 36 and stem 37 and cap 13 function as an integral unit when assembled.

The cap 13 is rotated to move the rod 32 and the carriage block 22 up and down, and hence the nut member 36 must be restrained against longitudinal motion, although it must turn within the sleeve 19; hence a lock collar 40 is secured inside the sleeve 19 at its upper end, this collar surrounding the stem 37 and bearing against the cap 13 at its upper end and against the nut member 36 at its lower end. The collar 40 is secured to the sleeve 19 by four screws 41 (Fig. 3) which extend through the reinforcing flange 16 on the sleeve. The reinforcing sleeve 16 is solidly secured to the sleeve 19, as by welding 43 at its upper and lower edges.

The bail 17 is of sufficient length to swing over the top of the cap 13, as shown in Fig. 2.

It is pivotally connected to the flanges 16 by drive pins 45 which are forced into apertures provided therefor in the flange 16 and locked in place by tapered pins 46.

In the construction of the device, the collar 40 is first assembled on the stem 37 and then the stem is screwed into the nut member 36 and the tapered pin 39 is installed. The foregoing operations are performed while the assembly of stem 37, collar 40 and nut member 36 is removed from the sleeve 19. The assembly is then slid into the tube and the collar 40 locked in place by inserting the screws 41.

The anchor may be operated as follows: First a hole of substantially the diameter of the sleeve 19 is preferably made in the ground to the full depth to which the anchor is to be set, if the ground is hard. A suitable tool for making the hole is shown in Fig. 5, and consists of a strong, thin-walled pipe 50 having a sharp lower edge 51 and having a drive cap 52 on its upper end.

The pipe 52 may be driven into the ground with a mallet and then pulled out, carrying a core of earth with it and leaving a hole of approximately the diameter of the anchor tube 19. The cap 52 of the coring tool is provided with a transverse aperture 53 into which the handle 15 may be inserted to pull the cap out of the ground. Removal of the pipe from the ground can sometimes be facilitated by rotating it before it is pulled, or while it is being pulled. The cap 52 is also provided with a vertical hole 54 through which any suitable rod or stick may be inserted to dislodge the core of earth from the tool before it is used again.

The lower end of the anchor is inserted in the hole prepared for it and then the bar 15 is inserted through the hole 14 in the cap 13 while the bail 17 is in vertical position, as shown in Fig. 2, after which the bar is rotated. Initial rotation rotates the cap 13 and the nut 36 through a small angle until the bar 15 bears against the side arms of the bail 17. Thereafter continued rotation of the bar 15 rotates the entire anchor, causing the screw flanges 12 to screw their way down into the earth until the anchor has been inserted to the desired depth.

The next step is to set the flukes 23 and 24 into extended position, as shown in Fig. 1, This is done by removing the bar 15 from the eye 14 and rocking the bail 17 into lower position, after which the bar 15 is reinserted in the eye 14 and rotated. This rotates the nut member 36 relative to the sleeve 19, the latter being restrained from rotation by the friction of the earth engaging the anchor, particularly the lower part having the flanges 12 thereon. The cooperating threads on the nut member 36 and the rod 32 are preferably left-hand threads so that continued rotation of the cap 13 clockwise forces the rod 32 and the carriage block 22 and the flukes 23 and 24 downwardly. During this downward movement the upper ends of the flukes pivot about the pin 30, while the lower ends of the flukes are swung outwardly by shoulders 56, against which the under surfaces of the flukes bear. Final downward movement of the block 22 extends the flukes into substantially horizontal position, as shown in Fig. 1. The bar 15 may then be removed, if desired, and used to set another anchor. The anchor line is then attached to the bail 17.

When the anchor is screwed into the ground, it will preferably be stopped in a position such that the bail 17 swings in a plane extending through the object to be anchored.

During expanding movement of the flukes 23 and 24 substantial pressure is developed between the shoulders 56 and the undersides of the flukes. It is, therefore, usually desirable to provide a U-shaped insert member 57 of hard material as a bearing member at this point. The U-shaped member 57 may fit over a tongue 58 provided in the casting 20 and be secured in place by a screw 59 extending through the side arms of the member 57 and the tongue 58.

When the anchor is to be removed the cap 13 is rotated in the opposite direction with the bar 15, causing the nut member 36 to elevate the rod 32 and the carriage block 22 to pull the flukes back into the bore of the anchor. During this movement the upper edges of the flukes bear against the shoulders 61 and 62 at the upper edges of the apertures 25 and 26, respectively. The casting 20 is relatively strong adjacent the shoulder 62 because of the presence of the screw flange 12. It is desirable to reinforce the casting adjacent the shoulder 61 by providing a narrow auxiliary screw flange 63. In general, the 05 force required to retract the flukes is much less than that required to set them and it is not necessary to provide special hardened material at the shoulders 61 and 62.

After the flukes have been completely retracted the anchor may be withdrawn from the ground by first removing the cross bar 15 from the eye 14, raising the bail 17 into vertical position, as shown in Fig. 2, and reinserting the bar 15 through both the eye 14 and the bail 17, and rotating the bar in counterclockwise direction to engage the bail IT and rotate the entire anchor in counter-clockwise direction.

Although it is usually desirable to employ the setting tool shown in Fig. 5, it is not essential that a hole be made with the setting tool to the full depth of the anchor. Particularly in soft, loose earth it may be desirable to make only a shallow hole, or none at all, to start the anchor into the ground.

It is to be understood that although for the purpose of explaining the invention a particular embodiment thereof has been described in great detail, various departures from the exact construction shown can be made without departing from the invention, which is to be limited only to the extent set forth in the appended claims.

I claim: 1. An anchor of the type described comprising a hollow tubular body member having openings for flukes therein, flukes within said tubular member expansible through said openings, carriage means reciprocable within said tubular member for expanding and contracting said flukes, a pair of cooperating threaded members positioned at least partially within said tubular member with one of said threaded members extending from the upper end thereof and having a cross hole therein for the insertion of a turning rod, means for restraining said one threaded member against longitudinal movement while so permitting rotation thereof with respect to said tubular member, means connecting said other threaded member to said carriage for reciprocating it in response to rotation of said one threaded member to expand or retract said flukes, and a bail pivotally mounted on said tubular member, the axis of the bail being below said cross hole in said one threaded member, and the transverse portion of the bail being above said transverse hole when the bail is in vertical position, whereby a cross member can be inserted through said transverse hole alone to turn said one threaded member relative to said tubular member when the bail is in lower position and is insertable in both said transverse hole and the bail when the latter is in vertical position to rotate the entire anchor.

2. Apparatus as described in claim 1, in which said means for preventing longitudinal motion of said one threaded member includes a thrust collar within said tubular member substantially juxtaposed to the pivot axis of said bail, and said means for pivotally connecting said bail to said tubular member includes a reinforcing flange extending all around said tubular member, with means for locking said reinforcing flange to said collar, and means for pivotally mounting said bail to said flange.

3. An anchor of the type described comprising a tubular member composed of a pipe section and a cast section secured to the lower end of the pipe section, said cast section having openings therein for the projection of flukes and having an integral thread flange thereon for screwing the anchor into the earth, said thread flange extending immediately above one of the said fluke openings for reinforcing said casting at that point, and an auxiliary short screw flange positioned immediately adjacent said other fluke opening, flukes adapted to be projected through the fluke openings, carriage means within the tubular member, and means pivotally connecting one end of each fluke to the carriage means, means for moving said carriage vertically within the tubular member to set and retract the flukes, said tubular member having means disposed therein between said flukes when the latter are in retracted position for bearing against the undersides of the flukes and projecting the free ends of the flukes outwardly and upwardly in response to downward movement of said carriage means.