Adjustable anchorage

Jan. 20, 1953

E. A. BLACK

2,625,815

ADJUSTABLE ANCHORAGE

Filed Oct. 23, 1943 ² SHEETS—SHEET 1

<img file="US2625815A_D0001.tif" />

Jan. 20, 1953

E. A. BLACK

2,625,815

ADJUSTABLE ANCHORAGE

SHEETS—SHEET 2

Filed Oct. 23, 1943

<img file="US2625815A_D0002.tif" />

Patented Jan. 20, 1953

2,625,815

UNITED STATES PATENT OFFICE

2,625,815

ADJUSTABLE ANCHORAGE Eric A. Black, Red Bank, N. J. Application October 23, 1943, Serial No. 507,356 14 Claims.

(Granted under Title sec.

The invention described herein may be manufactured and used by and for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to anchorages for adjustably sustaining structures such as towers, buildings, bridges, and the like.

It is important that certain structures be so constructed that they may always be maintained ₃exactly level. Hence, an adjustable anchorage is advisable. Such anchorages are particularly useful in towers for some types of directional antennae.

In installing anchorages, a usual practice is to pour the rough concrete of the foundation columns or pedestals a little below the required height and then fix the exact height with fine plastic cement and screed angles or the like. After the plastic cement has hardened, grout is used to build up to the height so fixed. In this way the foundation may be made exactly level. However, if the foundation settles later, all this work is undone. My adjustable anchorage makes it possible to eliminate the use of plastic cement and screed angles and to proceed with construction without waiting for plastic cement and later the grout to harden and if at any time the structure should not be exactly level, either because the foundation was not built exactly level originally or because it settled later, it may be readily corrected. . .

An object of the present invention is to provide an adjustable anchorage which, while having ample structural strength, nevertheless may be simply and quickly adjusted.

Another object is to provide such an anchorage which will so distribute the stresses that the size of a foundation may be safely reduced.

A further object is to provide an adjustable anchorage which will operate satisfactorily irrespective of weather, and the operating parts of which will remain free of dirt and moisture.

Another object is to reduce the construction time, materials and labor ordinarily necessary in building foundations.

Additional objects will appear from the following description.

In the drawings:

Figure 1 is an isometric view of an adjustable anchorage, embodying the present invention, in use at the base of a wooden radio antenna tower;

Figure 2 is a cross sectioned front view of the anchorage of Figure 1;

Figure 3 is an enlarged perspective of the uppei end of the sleeve of Figure (Cl. 72—77)

35, U. S. Code (1952), 266).

Figure 4 is an enlarged isometric view of the strap plate of Figure 1;

Figure 5 is an enlarged cross sectioned left side view of the weather-proof gasket and wedge of Figure 1;

Figure 6 is a horizontal section, along the line 6—S of Figure 5;

Figure 7 is an enlarged cross section of the lower end of the shaft of Figure 2; showing the wedge slots and part of the lubrication system,.

Figure 8 is an enlarged sectioned side view of the anchor plate of Figure 2;

Figure 9 is a side elevation of my adjustable anchorage in use with a metal I beam; and

Figure 10 is a sectioned side view of a simplified form of my adjustable anchorage.

Figures 1 through 8 of the drawings show my adjustable anchorage in use at the base of a fourlegged, wooden, radio antenna tower (only one leg being shown). Each leg 16 is anchored to a concrete foundation column (5 by means of two of my adjustable anchorages, eight such anchorages being used for the entire structure. In Figure 1, one anchorage may be seen, another being on the far side of leg 16.

Referring now to Figures 1 through 8, and particularly to Figure 2, a preferred form of my adjustable anchorage comprises two main cooperating parts, the lower stationary male member A and the upper movable female member B.

The male member A (see Figure 2) is an elongated cylindrical anchor rod 8, which, at its upper end portion 24, is of a greater diameter. Said anchor rod 8 is threaded throughout said wider portion 24 and also at its lower end 23. The lower end of said anchor rod 8 is provided with a pair of hexagonal nuts 10 and 11, the upper nut iO being welded to the rod 8 and the lower nut il being fitted with a cotter pin 31. The : lower end of anchor rod 8 extends through a hole in a steel anchor plate S, being fastened thereto by the two nuts 10 and 11. Said anchor plate 9 is large enough so that the two adjustable .anchorages, attached to one leg 16 of the tower, 5 may be fastened to it (see Figures 2 and 8). To prevent rotation of the anchor rod 8, a locking plate 32, abutting one of the flats of nut Ii, is bolted to the under side of the anchor plate 9 by means of bolts 33. The anchor plate 9 and Ό the lower portion of anchor rod 8 are solidly embedded in the concrete column 15.

The female member B (see Figure 2) comprises a sleeve 1, which is an internally-threaded steel tube, and the shaft 20, which is a steel shaft 15 threaded at both ends. The sleeve Ί and shaft

2,625,815 are threadably coupled and then permanently welded together so as to form a unit. To facilitate and insure a good weld, the upper end of sleeve 7 has two longitudinal slots 34 (see Figure 3). The sleeve 7 and the upper end 24 of the anchor rod 8 are in operable threaded engagement. The lower end of sleeve 7 is closed by a washer 38, which is held in place on the sleeve 7 by several machine screws 39.

The upper threaded end of shaft 29 is fitted with a square washer 26 and a pair of hexagonal nuts 2 and 3. The upper nut 2 is pierced by a transverse hole 36 and the upper end of shaft 20 is similarly pierced by a transverse hole ί. When the nut 2 is raised so that these holes I and 36 15 are in register, a cylindrical steel pin (not shown), having a length equal to the fiat-to-fiat diameter of nut 2, may be inserted through both holes to thereby lock said nut and shaft together, whence the shaft may be rotated by using a 20 wrench on the nut. The lower portion of shaft 20 is pierced axially by a lubrication channel 30 (see Figure 7), into which lead several transverse threaded openings 35, provided with “Alemite”type lubrication fittings 2 ί. The shaft 20 has two 25 trapezoidally-shaped, shallow slots 37 (see Figures 5, 6, and 7), on opposite sides of the shaft, to accommodate a wedge 22. Said wedge 22 is a U-shaped metal strap, each arm of which has its upper edge cut off at an angle so as to form a so wedge. (See Figures 5 and 6).

The shaft 20 extends through a vertical channel 41, formed by a loop 25 in a steel strap plate 18, said channel being a loose fit about said shaft 20 (see Figures 1, 2, and 4). The loop 25 is cut 35 off at its lower end to expose the lubrication fittings 21 and the wedge 22. Said strap plate 18 is fastened to the wooden leg 16 of the antenna tower by means of bolts 45 which also extend through an identical strap plate 18, on the oppo- 40 site side of the leg. The bottom of the leg 16 rests upon a flat metal base plate 12, which has a hole 44 to freely accommodate shaft 20. To the lower surface of said base plate 12, coaxial with hole 44, is welded a short tubular collar 13, which .5 fits down into a cylindrical recess 47 in the concrete column 15, and Is vertically movable in said recess. Said base plate 12 rests upon an annular, ball-type, thrust bearing 29, which encircles shaft 29, and which bearing in turn rests upon the upper end of the sleeve 7. For protecting the anchorage mechanism and providing room to allow some transverse play thereof, a pipe 28 is solidly embedded in a cylindrical recess in the concrete, the diameter of said pipe being less than that of collar 13 but greater than that of the sleeve 7.

In order to keep water and dirt from entering the hole 44 in the base plate 12 and seeping into the working parts, there is a weather-proof, annular gasket 19, of L-shaped cross-section (see Figure 5) surrounding shaft 20 and resting on the base plate. Said gasket 19 is held in place by a split adjustable clamp 27, of similar cross-section, which is forced downward by means of the U-shaped wedge 22 which fits into the wedge slots 37.

Gusset plates 42, for holding diagonal braces 17 of the tower, are welded to two adjacent sides of the base plate 12 (see Figure 1).

The threaded connection between the sleeve 7 and the anchor rod 8 is kept lubricated by means of the lubrication fitting 21, the lubricant dropping down through the channel 30. The anchor rod 8 is kept from being accidentally unscrewed from the sleeve 7 by the washer 38.

My adjustable anchorage may also be used on a metal tower, one construction being indicated in Figure 9, where the shaft 20 extends through two holes cut in the flanges of a metal I beam 40. In this arrangement, the collar 13 (not shown in Figure 9, but see Figure 10 for similar construction) is welded directly to the under surface of the I beam 46, no separate base plate being necessary. The other parts are similar to those already described and shown in Figures 1 through 8 except that the strap plate 18, the bolts 45, the washer 26 and the base plate 12 are not needed in this construction.

To adjust my anchorage shown in Figures 1 ; through 9, the wedge 22 is removed, and the clamp 27 and the nuts 2 and 3 are loosened. The nut 2 is raised until hole 36 in the nut is in register with hole I in the shaft 20. The cylindrical steel pin, already described, is then inserted through the holes I and 36 so that the shaft 20 may be rotated by means of a wrench on nut 2. The sleeve 7, being integral with the shaft 28, will thus be caused to rotate. As the anchor rod 8 is immovably embedded in the concrete column 15, the rotation of the sleeve 7 will cause said sleeve to move vertically, thereby causing the thrust bearing 23, the base plate 12, and the leg 16 of the tower (it will be the I-beam 46 in the construction shown in Figure 9) to move with it. After adjustment, the steel pin is removed and the nuts 3 and 2 are retightened. The wedge 22 and the clamp 27 are then reinstalled and retightened. After the concrete columns 15 have settled and final adjustment of the anchorages has been made, any space between the concrete column 15 and base plate (or the I-beam 46 in Figure 9) may be filled in with a suitable shimming means, such as grout 43, so that the concrete column 15 directly receives part of the compressive load.

It is good practice to install a drainage tube (not shown) from the inside of the pipe 28, through the wall of the lower end of said nipe 28 and the concrete columns 15, so as to allow any water, which may possibly get into the pipe 28, to drain off. However, even should some water accumulate inside pipe 28, it will not affect the operation of the anchorage because the movable parts are grease packed. Even should some ice form within pipe 28, the movable parts will still be operable as the sleeve 7 (Figure 3) is cylindrical and may therefore rotate within the ice.

A simplified form of my adjustable anchorage, suitable for light work, is shown in Figure 10, where it is used to anchor a wooden tower. Fas55 tened to the tower leg 16, by bolts 49, is a short length of U -shaped channel steel 51. Both flanges 53 and 55 of the channel steel 5i have apertures to accommodate the cylindrical anchor rod 57. Welded to the trader surface of the lower flange GO 55 is a short tubular collar 13 which is vertically slidable in a cylindrical recess 47 in the concrete column i 5. The pipe 28, nuts I8 and 11, cotter pin 31, anchor plate 9, locking plate 32 and bolts 33 are similar to those parts as already described. The anchor rod 57 is threaded at both ends. The lower portion is firmly embedded in the concrete column 15. The upper threaded end is fitted with two nuts 59 and 6!, one being above the flange 53 and the other below it.

The adjustment of this anchorage is very simple. If the tower is to be raised, the nut 59 is loosened, the nut 6 ί is raised the desired amount (the tower leg (6 moving up with it) and the nut 59 is retightened. If the leg 16 is to be low75 ered, the nut 61 is first lowered (the leg i6 mov•ο

2,625,815 member, the leg of the structure being sustained by said base plate; strap means loosely encircling said member and secured to said leg; and hold down means on said member to prevent said strap means from moving upward relative to said member.

2. An adjustable anchorage to position and sustain a structure, comprising a foundation, an elongated anchored member firmly embedded in said foundation for a portion of its length, an adjusting member in movable engagement with said anchored member, a base plate supportingsaid structure, shimming means positioned intermediate said base plate and said foundation, said base plate at all times being at least partly supported by said adjusting member whereby, upon operable movement of said adjusting member, the structure may be positioned relative to said foundation, and whereby, upon positioning of said shimming means, the structure rests upon the base plate and the structure and base plate are supported by said foundation partly through said shimming means and also partly through said anchored member.

3. A device adjustably sustaining a structure, including a foundation, a standard of adjustable length, an elongated portion of said standard being firmly embedded in said foundation, fastening means coupling said structure to said 30 standard, shimming means positioned between said structure and said foundation to transmit compressive forces . from said structure to said foundation, whereby said structure is positionable relative to said foundation and compressive 35 forces may be transmitted to the foundation from the structure through both said shimming means and said standard.

4. An adjustable anchorage sustaining a structure, comprising a foundation, a substantially ing down with it) and then the nut 59 is retightened.

It is to be noted that, in the embodiments of my invention described herein, the anchor rods 8 and 57 are firmly embedded in concrete for an appreciable portion of their length. A metal rod sustains a greater load per unit of cross-sectional area than concrete. In my anchorage the compression load is transmitted through the anchor rod into the concrete foundation column. This distribution of the load enables both the concrete column and the base plate resting upon it to be made smaller than with anchorages which do not transmit compression. Thus the use of my anchorage results in a considerable saving in material.

A formula for ascertaining the safe area of a concrete column is the following:

_Λ _P_ ^71c-500 where Ac indicates the net area of the concrete in square inches and P is the load in pounds. When a steel anchor rod under compression is used, the formula is as follows:

P—750041 _s^Ac~ 500 where As is the area of the steel in square inches. Thus, it is seen that the steel rod sustains a considerable portion of the load with a resultant reduction in the size of the steel base plate and the concrete foundation and a corresponding reduction in the labor necessary to construct the same.

Where the structure to be sustained has a considerable dead weight, a further economy of materials and labor may be accomplished. The anchor rods may be put into compression by delaying the grouting or other shimming until enough vertically disposed anchor rod firmly embedded of the structure has been erected to obtain the j_n the foundation for a portion of its length, shimming means positioned between said structure and said foundation to transmit compressive forces therebetween, adjusting means coupled to said structure and in threadable engagement with said anchor rod, whereby, upon rotation of said adjusting means and positioning of said shimming means, the structure may be moved substantially vertically relative to said foundation and compressive stresses may be transmitted to the foundation from the structure through of the structure has been erected to obtain the desired load (?') upon said rods. After the grout has hardened the erection of the structure is completed. When so constructed, the formula will be:

P-P'-7500A, 500

When used for fixed column bases of buildings which have to transmit axial loads and bending moments to the foundation, a considerable sav50 ing can also be effected by the use of my adjustable anchorages as they will transmit an increased part of the moment as well as a part of the axial load.

Although I have shown my invention in a vertical position, its use need not be limited thereto. I have shown preferred embodiments of my invention, but it is obvious that other uses as well as changes or omissions in structure may be made without departing from the spirit thereof.