Concrete anchoring device and method

A concrete anchoring device for a standard nut or bolt, comprising: at least one pair of identical wedge-shaped members aligned in mirror image relationship with their thinnest tapered edges in juxtaposition separated by a distance Y; and adhesive tape spanning distance Y and removably adhered to a substantial portion of the top surfaces of each pair of identical wedge-shaped members; and a method of using the concrete anchoring device to anchor a standard bolt head or bolt nut within a pre-drilled hole.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to construction materials and 
methods, and more particularly, is concerned with a concrete anchoring 
device and method of use to provide an inexpensive, and potentially 
recoverable, concrete anchor for a standard nut and bolt, or the like. 
2. Description of the Prior Art 
Existing concrete anchoring devices and methods of use include specially 
manufactured bolts having integrally attached anchoring devices that 
cooperate with the bolts to provide a substantially permanent anchoring 
attachment of the bolts and their anchoring devices within prepared 
receiving holes in the concrete. FIGS. 1 and 2 (Prior Art) illustrate two 
of the most common concrete anchoring devices of the prior art. 
The device illustrated in FIG. 1 includes a specialty bolt 10 that is 
threadingly received within one end of a fitting 12 that has been 
furnished with a through-bore 14 that tapers down to a diameter smaller 
than that of the bolt 10 at its other, unthreaded end 16. At end 16 of 
fitting 12, the fitting has been cut into quarter sections 18. Thus, when 
the combined bolt 10 and fitting 12 are placed into a pre-drilled concrete 
hole selectively sized to be just slightly larger than the diameter of 
fitting 12, advancing bolt 12 into the threaded end of fitting 12 by 
clockwise rotation of bolt head 20 will force bolt 10 through the tapered 
through bore 14 toward the unthreaded end 16. This will force quarter 
sections 18 outwardly and into contact with the walls of the pre-drilled 
concrete hole. The frictional forces thus created between quarter sections 
18 and the walls of the pre-drilled concrete hole anchor fitting 12, and 
bolt 10, within the pre-drilled concrete hole. 
The device illustrated in FIG. 2 includes a specialty rod 30 that has been 
threaded and provided with a nut 32 at one end. At the opposite end 36, 
the rod has been milled to provide a conically tapered section 36 that 
begins at end 36 and runs toward the opposite threaded end. An expandable 
sleeve 38 has been fitted over the portion of the conically tapered 
section 36 that is closest to the threaded end of rod 30. On opposite 
sides of expandable sleeve 38 are a pair of integral protrusions 40 (only 
one shown) that protrude outwardly beyond the diameter of rod 30. When the 
combined rod 30 and expandable sleeve 38 are placed into a pre-drilled 
concrete hole selectively sized to snugly receive the protrusions 40 on 
expandable sleeve 38, advancing nut 32 by clockwise rotation toward end 36 
of rod 30 against the concrete surface surrounding the pre-drilled 
concrete hole will begin forcing rod 30 out of the pre-drilled concrete 
hole. Expandable sleeve 38 will remain fairly stationary, however, due to 
the frictional forces between protrusions 40 and the pre-drilled concrete 
hole. As end 34 moves up the pre-drilled concrete hole, expandable sleeve 
38 will be forced outwardly by the increasing diameter of the conically 
tapered section 36, increasing the frictional forces upon protrusions 40 
until rod 30 can no longer be advanced out of the pre-drilled concrete 
hole. The frictional forces thus created between protrusions 40 and the 
walls of the pre-drilled concrete hole firmly anchor rod 40 within the 
pre-drilled concrete hole. 
Both of the prior art devices illustrated in FIGS. 1 and 2 are relatively 
expensive, and their methods of use render them useful for only a single 
application. Also, they are not adjustable to accommodate varyingly sized 
pre-drilled concrete holes. A given anchor of the type illustrated in 
either FIG. 1 or 2 would be sized to fit only pre-drilled concrete holes 
of a given diameter, within limited tolerances. Furthermore, when the 
device of FIG. 1 had served its purpose, bolt 10 would be backed out of 
fitting 12, and the pre-drilled concrete hole would be filled with 
concrete. In the case of the device of FIG. 2, nut 32 would be backed off 
and the rod 30 would be driven down until it was wholly within the 
pre-drilled concrete hole, which are always drilled deeper than the length 
of the anchoring device to be used, and the pre-drilled concrete hole 
would be filled with concrete. In each case, the essential elements of the 
anchoring devices would be irretrievably lost. 
SUMMARY OF THE INVENTION 
The concrete anchoring device and method of the present invention provide 
an inexpensive, and potentially recoverable, alternative to the concrete 
anchoring devices and methods of the prior art, that may be utilized with 
any bolt desired to be used as a concrete anchor, and which also provide 
adjustability to accommodate a range of bolt and pre-drilled concrete hole 
diameters. 
One embodiment of the present invention is a concrete anchoring device for 
a standard nut or bolt, comprising at least one pair of identical 
wedge-shaped members aligned in mirror image relationship with their 
thinnest tapered edges in juxtaposition separated by a distance Y; and 
adhesive tape spanning distance Y and removably adhered to a substantial 
portion of the top surfaces of each pair of identical wedge-shaped 
members. 
Another embodiment of the present invention is a method of anchoring a 
standard bolt head within a pre-drilled hole in concrete, comprising: 
providing at least one pair of identical wedge-shaped members aligned in 
mirror image relationship with their thinnest tapered edges in 
juxtaposition separated by a distance Y; adjusting distance Y to be less 
than the width dimension of the head of the standard bolt to be anchored; 
spanning distance Y with adhesive tape and removably adhering the adhesive 
tape to a substantial portion of the top surfaces of each pair of 
identical wedge-shaped members; positioning each pair of identical 
wedge-shaped members over a pre-drilled hole with distance Y centered over 
the hole and with the adhesive surface of the adhesive tape facing the 
hole; centering the bolt head of the adjusting step over distance Y; 
forcing the bolt head of the adjusting step into the pre-drilled hole of 
the positioning step until each pair of identical wedge-shaped members lie 
flush against the wall of the pre-drilled hole; and urging the bolt head 
of the adjusting step upwardly to anchor the bolt head in the pre-drilled 
hole of the positioning step. 
Yet another embodiment of the present invention is a method of anchoring a 
standard bolt nut within a pre-drilled hole in concrete, comprising: 
providing at least one pair of identical wedge-shaped members aligned in 
mirror image relationship with their thinnest tapered edges in 
juxtaposition separated by a distance Y; adjusting distance Y to be less 
than the width dimension of the bolt nut to be anchored; spanning distance 
Y with adhesive tape and removably adhering the adhesive tape to a 
substantial portion of the top surfaces of each pair of identical 
wedge-shaped members; positioning each pair of identical wedge-shaped 
members over a pre-drilled hole with distance Y centered over the hole and 
with the adhesive surface of the adhesive tape facing the hole; centering 
over distance Y the bolt nut of the adjusting step with a standard bolt 
attached; forcing the bolt nut of the adjusting step into the pre-drilled 
hole of the positioning step until each pair of identical wedge-shaped 
members lie flush against the wall of the pre-drilled hole; and urging the 
bolt nut of the adjusting step upwardly to anchor the bolt nut in the 
pre-drilled hole of the positioning step. 
It is an object of the present invention to provide a concrete anchoring 
device that is inexpensive, and potentially recoverable, and which also 
provides adjustability to accommodate a range of pre-drilled concrete hole 
diameters and anchor sizes, using commonly available bolts and nuts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
For the purposes of promoting an understanding of the principles of the 
invention, reference will now be made to the embodiments illustrated in 
the drawings and specific language will be used to describe the same. It 
will nevertheless be understood that no limitation of the scope of the 
invention is intended thereby, such alterations and further modifications 
in the illustrated device, and such further applications of the principles 
of the invention as illustrated in the drawings being contemplated as 
would normally occur to one skilled in the art to which the invention 
relates. 
Referring now to the drawings, there is illustrated in FIGS. 3 and 4 a 
preferred embodiment of the concrete anchor 50 of the present invention. 
Concrete anchor 50 comprises a pair of identical wedge-shaped members 52 
and 54 that are aligned in mirror image relationship with their thinnest 
tapered edges 53 and 55, respectively, in juxtaposition separated by a 
distance Y. As will be discussed below, distance Y is selected to 
correspond to the bolt size to be anchored by concrete anchor 50 in a 
pre-drilled concrete hole 62. Wedge-shaped members 52 and 54 are held in 
this described and illustrated position in the preferred embodiment by a 
single piece of cellophane adhesive tape 56 that spans distance Y and 
contacts a substantial portion of the top surfaces 58 and 60 of 
wedge-shape members 52 and 54. 
Referring now to FIGS. 5-7, there is illustrated the preferred method of 
utilizing the concrete anchor 50 of the preferred embodiment. A 
pre-drilled hole 62, of predetermined diameter and depth, is provided in 
concrete at a location selected for anchoring a standard bolt 64 having an 
octagonal head 66. For anchoring purposes, bolt 64 is provided with a 
standard flat washer 68 having an outer diameter greater than the diameter 
of pre-drilled hole 62, and a nut 70. Referring to FIG. 5, concrete anchor 
50 is placed across the diameter of pre-drilled hole 62. Distance Y is 
selected to be some dimension less than the width of bolt head 66 yet 
large enough to allow placement of anchor 50 within pre-drilled hole 62 in 
the manner to be described below. 
Referring again to FIG. 5, in the embodiment illustrated, bolt 64 is 
positioned over the pre-drilled hole with bolt head 66 against cellophane 
adhesive tape 56. As described above, because distance Y has been selected 
to be less than the width of bolt head 66, bolt head 66 will also overlie 
a portion of the top surfaces 58 and 60 of wedge-shaped members 52 and 54 
closest to their thinnest tapered edges. Referring now to FIG. 6, as bolt 
64 is pushed downwardly into pre-drilled hole 62, the thinnest tapered 
edges 53 and 55 of wedge-shaped members 58 an 60 will pivot into 
pre-drilled hole 62, about the upper rim of pre-drilled hole 62, under the 
influence of cellophane adhesive tape 56. The pivotal shear forces brought 
to bear upon cellophane adhesive tape 56 as bolt head 66 is forced 
downwardly into pre-drilled hole 62 will cause cellophane adhesive tape 56 
to be controllably pulled away from the top surfaces 58 and 60 of 
wedge-shaped members 52 and 54 closest to their thinnest tapered edges 53 
and 55. Meanwhile, the frictional forces between bolt head 66 and the 
cellophane adhesive tape 56 still adhered to the top surfaces 58 and 60 of 
wedge-shaped members 52 and 54 prevent the wedge-shaped members 52 and 54 
from prematurely sliding into pre-drilled hole 62. 
Referring now to FIG. 7, when bolt head 66 has been forced into pre-drilled 
hole 62 a sufficient distance, gravity in cooperation with the shear 
forces upon the cellophane adhesive tape still adhered to the top surfaces 
58 and 60 of wedge-shaped members 52 and 54 and the increasing taper of 
these members above bolt head 66 within the pre-drilled hole will cause 
wedge-shaped members 52 and 54 to fall into pre-drilled hole 62 and into a 
vertically oriented position, flush with the walls of pre-drilled hole 62, 
as illustrated. Because wedge-shaped members 52 and 54 were pivoted into 
pre-drilled hole 62 thinnest-tapered-edge first, the increasing taper of 
wedge-shaped members 52 and 54 above bolt head 66 will not only prevent 
wedge-shaped members 52 and 54 from falling further into pre-drilled hole 
62, but the frictional forces between the surfaces of wedge-shaped members 
52 and 54 against the wall of pre-drilled hole 62 will also prevent bolt 
head 66 from being pulled out of pre-drilled hole 62. Therefore, as nut 70 
is tightened against flat washer 68, resting against the concrete surface 
surrounding pre-drilled hole 62, bolt head 66 will be anchored in place by 
concrete anchor 50 of the preferred embodiment. 
As described, almost any conventional bolt 64 may be anchored with the 
concrete anchor 50 of the present invention. In addition, rather than 
introduce bolt 64 into the pre-drilled bolt 62 bolt head 66 first, the 
bolt 64, flat washer 68 and nut 70 assembly illustrated in FIGS. 5-7 can 
be inverted and introduced into pre-drilled hole 62 with the nut 70, 
first, as illustrated in FIGS. 8-10. In this application, nut 70 would be 
anchored in place in the same fashion as was bolt head 66, in the 
description, above. In this application, however, the wedge-shaped members 
52 and 54 could be recovered after the anchor had served its purpose. 
Referring to FIG. 11, bolt 64 would be threadingly removed from nut 70, 
and nut 70 could then be physically driven downward further into 
pre-drilled hole 62 by breaking through cellophane adhesive tape 56. Doing 
so would free wedge-shaped members 52 and 54, and nut 70, and they could 
be removed from the pre-drilled hole 62 for reuse. Simply re-applying 
cellophane adhesive tape as described above would ready the wedge-shaped 
members 52 and 54 to serve as the concrete anchor 50 of FIGS. 3 and 4. 
As will be appreciated by those of ordinary skill in this art, the size and 
depth of pre-drilled hole 62 will be determined by the size of bolt 64 to 
be anchored therein, which will determine the appropriate overall 
dimensions and degrees of taper of the wedge-shaped members 52 and 54, and 
the distance Y, as described above. It will be appreciated that the depth 
of pre-drilled hole 62 will be oversized, as is customary when using 
anchoring devices of the prior art (i.e., FIGS. 1 and 2). Also, for very 
large diameter pre-drilled holes 62, it has been found to be advantageous 
to use two or more concrete anchors 50 spaced evenly about the 
circumference of the opening of pre-drilled hole 62. In all other respects 
the function of a plurality of concrete anchors 50 is the same as for a 
single concrete anchor 50, as described and illustrated. 
In the preferred embodiments to date, wedge-shaped members 52 and 54 have 
been fashioned from steel, but any sufficiently strong material could be 
used in place of steel. Also, as described, cellophane adhesive tape as 
been the preferred material for releasably positioning wedge-shaped 
members 52 and 54 as described and illustrated. However, any other similar 
material that would function similarly would also be useful in place of 
cellophane adhesive tape. 
The concrete anchor 50 and method described and illustrated works best on 
flat, stationary surfaces. The concrete anchor 50 and method described and 
illustrated could be utilized in overhead applications or in applications 
involving vibration, as well, if provisions were made to epoxy, or 
otherwise affix wedge-shaped members 52 and 54 into the position 
illustrated in FIG. 7. 
While the invention has been illustrated and described in detail in the 
drawings and foregoing description, the same is to be considered as 
illustrative and not restrictive in character, it being understood that 
only the preferred embodiments have been shown and described and that all 
changes and modifications that come within the spirit of the invention are 
desired to be protected.