SELF-UNDERCUT EXPANSION ANCHOR SYSTEM WITH IMPROVED
CUTTERS
1.
FIELD
The invention relates to the field of anchors, and more specifically to a self-undercut expansion anchor system having improved bore cutters for use in cementitious materials.
SUMMARY
The present disclosure provides for self-undercut expansion anchor system for use in a pre-drilled bore hole, comprising an anchor further comprised of at least two cutters, the at least two cutters connected to and positioned below at least two corresponding spreading lamellae of the anchor, to cut through a material of the pre-drilled bore hole; and, a bullet connected to the anchor to provide a surface on which the at least two cutters and at least two spreading lamellae can expand and radially cut into the pre-drilled bore hole, wherein the lower end of the anchor expands radially over the bullet to set the system in the pre-drilled bore hole, and wherein a wide edge of the at least two cutters is flush with slits of the anchor.
BRIEF DESCRIPTION OF THE DRAWINGS
The following figures serve to illustrate various embodiments of features of the disclosure. These figures are illustrative and are not intended to be limiting.
Figure 1 is a perspective exploded view of a self-undercut expansion anchor system, according to an embodiment of the present disclosure;
Figure 2 is a bottom view of an anchor taken along the lines FIG. 2 as shown in Figure 1, according to an embodiment of the present disclosure;
Figure 3 is side cross-sectional view of the anchor taken along the lines FIG. 3 as shown in Figure 2, according to an embodiment of the present disclosure;
Figure 4 is a perspective exploded view of the self-undercut anchor system and a setting tool, according to an embodiment of the present disclosure;
Figure 5 is a side cross-sectional view of the setting tool positioned within the self-undercut expansion anchor system, according to an embodiment of the present disclosure;
Figure 6 is a perspective view of the setting tool being hammered and rotated thus forcing the anchor to spread over a bullet of the self-undercut expansion anchor system, according to an embodiment of the present disclosure; and, Figure 7 is a side cross-sectional view of the setting tool being hammered and rotated thus forcing the anchor to spread over the bullet of the self-undercut expansion anchor system, according to an embodiment of the present disclosure.
2 DETAILED DESCRIPTION
The following embodiments are merely illustrative and are not intended to be limiting. It will be appreciated that various modifications and/or alterations to the embodiments described herein may be made without departing from the disclosure and any modifications and/or alterations are within the scope of the contemplated disclosure.
With reference to Figures 1, 2 and 3 and according to an embodiment of the present disclosure, a self-undercut expansion anchor system 10 for use in a pre-drilled bore holes is shown, preferably comprising an anchor 15 and a bullet 20.
The anchor 15 is further comprised of at least two jagged cutters 25, each of the cutters 25 positioned at a lower end of the anchor 15 on and below spreading lamellae 34, 36.
Although this preferred embodiment illustrates four cutters 25, a worker skilled in the art would understand that any number of cutters are possible, although four cutters have been shown to be optimal. A worker skilled in the art would appreciate that the cutters 25 could be in the form of brazed carbide on the anchor 15, without departing from the scope of the disclosure. Each of the cutters 25 is further comprised of a wide edge 27 and a narrow edge 28, such edges 27, 28 will be further described below. The anchor 15 is also comprised of at least two, and preferably four, slits 30 positioned at the lower end of the anchor 15. As shown, the II
four slits 30 are positioned equidistantly from one another on the anchor 15 and separate the spreading lamellae 34, 36.
The slits 30 run up along the length of the anchor 15, from the lower end of the anchor 15 until approximately halfway up the anchor 15. As shown, the wide edges 27 of the four cutters
3 25 are preferably positioned adjacent to and flush with each of the four slits 30. A worker skilled in the art would appreciate that the slits 30 allow for the lamellae 34, 36 and cutters 25 to spread radially over the bullet 20 during setting of the anchor 15. Indeed, the anchor 15 is further comprised of an annular recess 32 to facilitate the radial spreading of the lamellae 34, 36 and cutters 25 over the bullet 20.
With specific reference to Figures 2 and 3, the cutters 25 are shown having a wide edge 27 and a narrow edge 28. The wide edge 27 of the cutters 25 will be the first point of contact between the anchor 15 and the inner walls of the bore hole (not shown). Indeed, the wide edge 27 of the cutters 25 extends wider than the circumference of the lamellae 34, 36.
The outer periphery of the wide edge 27 of the cutters 25 is the same width as the diameter of an upper portion 40 of the anchor 15, as shown by the stippled line 41 in Figure 3. Such a shape, width and placement of the cutters 25 has been shown to provide an improved setting of the anchor 15 in a bore hole. The cutters 25 are comprised of curved inner sides 42, the curved inner sides 42 positioned in proximity to but not flush with an inner wall 44 of the anchor 15. The spacing between the curved inner sides 42 of the cutters 25 and the inner wall 44 of the anchor 15 is necessary as such a spacing ensures that the cutters 25 do not come in contact with an upper portion of the cone portion (not shown) of the bullet (not shown). This reduces and can eliminate friction between the cutters 25 and the bullet (not shown) during expansion of the anchor system (not shown).
4 With reference to Figures 4, 5, 6 and 7 and according an embodiment of the present disclosure, the self-undercut expansion system 10 is shown being connected to a setting tool 50 and having the setting tool 50 expand the anchor 15 over the bullet 20. With specific reference to Figure 4, the anchor 15 is shown positioned over the neck 45 of a bullet 20. A setting tool 50 is shown about to connect to the anchor 15. With specific reference to Figure 5, the setting tool 50 is shown inserted within the upper portion 40 of the anchor 15. A lower portion of the spreading lamellae 34, 36 is showing surrounding the neck 45 of the bullet 20. Meanwhile, the cutters 25 are positioned over an upper portion of the cone portion 55 of the bullet 20 without making contact with the cone portion 55. Indeed, spaces 60 are provided between the cutters 25 and the upper portion of the cone portion 55 of the bullet 20, to eliminate friction that would otherwise occur if the cutters 25 made contact with the cone portion 55. With specific reference to Figures 6 and 7, the setting tool 50 is shown being hammered and rotated, usually by a rotary hammer drill or another impact tool, to force the spreading lamellae 34, 36 of the anchor 15 over the cone portion 55 of the bullet 20. The cutters 25, connected to and positioned below the spreading lamellae 34, 36 abut against and dig into the inner wall of the bore hole and serve to secure the anchor 15 in an undercut position within the bore hole.
Many modifications of the embodiments described herein as well as other embodiments may be evident to a person skilled in the art having the benefit of the teachings presented in the foregoing description and associated drawings. It is understood that these modifications and additional embodiments are captured within the scope of the contemplated disclosure which is not to be limited to the specific embodiment disclosed.