Expansion anchor with protected optical code

Abstract

An expansion anchor includes an anchor bolt with a rear face, a displaceable body located adjacent to the anchor bolt, and at least one wedge body located in a front region of the anchor bolt. The wedge body has a converging zone for displacing the displaceable body. An optically readable code is located at the rear face of the anchor bolt. At least one code protection protrusion projects from the anchor bolt rearwardly beyond the optically readable code.

Claims

1. An expansion anchor, comprising: an anchor bolt with a rear face; a displaceable body disposed adjacent to the anchor bolt; a wedge body disposed in a front region of the anchor bolt, wherein the wedge body has a converging zone for displacing the displaceable body; an optically readable code disposed at the rear face of the anchor bolt; and a code protection protrusion which projects from the anchor bolt rearwardly beyond the optically readable code.

2. The expansion anchor according to claim 1, wherein the code protection protrusion and the anchor bolt are monolithic.

3. The expansion anchor according to claim 1, wherein the code protection protrusion forms a sector of an annulus that surrounds the optically readable code.

4. The expansion anchor according to claim 1, wherein the code protection protrusion forms an annulus that surrounds the optically readable code.

5. The expansion anchor according to claim 4, wherein the annulus has a constant height.

6. The expansion anchor according to claim 1, wherein the code protection protrusion has a maximum height that is greater than 0.4 mm.

7. The expansion anchor according to claim 1, wherein the code protection protrusion has a maximum radial width that is greater than 0.5 mm.

8. The expansion anchor according to claim 1, wherein the optically readable code is an at least two-dimensional barcode.

9. The expansion anchor according to claim 1, wherein the anchor bolt has a forwardly-facing shoulder for advancing the displaceable body into a borehole.

10. A method for using the expansion anchor according to claim 1, comprising the step of: reading the optically readable code using a sensor.

11. The method according to claim 10 further comprising the steps of moving the wedge body rearwards relative to the displaceable body and radially displacing the displaceable body by the step of moving.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of an inventive expansion anchor;

(2) FIG. 2 is a longitudinal section of the expansion anchor of FIG. 1;

(3) FIG. 3 is a cut-out of FIG. 2 in the rear region of the expansion anchor encircled in FIG. 2; and

(4) FIG. 4 is an isometric view of the rear region of the expansion anchor of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

(5) The expansion anchor shown in the Figures comprises an elongate anchor bolt 10 defining a longitudinal axis 99, a displaceable body 30, and a wedge body 12 for the displaceable body 30, which wedge body 12 is provided on the anchor bolt 10 in the vicinity of the front end of the anchor bolt 10. The displaceable body 30 is an expansion sleeve which surrounds the anchor bolt 10. It is provided with a plurality of slits 36, which originate from the front end of the displaceable body 30 and extend towards the rear end of the displaceable body 30.

(6) As illustrated in particular in FIG. 2, the wedge body 12 has a converging zone 23 designed for radially expanding the displaceable body 30, i.e., the expansion sleeve, when the wedge body 12 is drawn into the displaceable body 30 in the rearwards direction, i.e., when the displaceable body 30 is moved forwards relative to the wedge body 12 onto the wedge body 12. For this purpose, the lateral surface of the wedge body 12 converges towards the rear of the anchor bolt 10, i.e., it converges towards the displaceable body 30, at least before the expansion anchor is installed. In the present example, the wedge body 12 lateral surface is conical in the converging zone 23, with a focus of convergence on the longitudinal axis 99. However, this is merely an example and other converging designs are also possible.

(7) In the present example, the wedge body 12 also has a transition zone 22, which is located forwards of and adjacent to the converging zone 23, and a tip zone 21, which is located forwards of and adjacent to the transition zone 22. In the transition zone 22, the rearward convergence is smaller as compared to the converging zone 23 or the rearward convergence is even zero, but preferably not reverse, i.e., it is not a forward convergence. In the present example, convergence is absent, i.e., zero, in the converging zone 23 and the wedge body 12 has a cylindrical lateral surface in the converging zone 23, in particular cylindrical with a circular base. In the tip zone 21, the lateral surface of the wedge body 12 converges towards the front end of the anchor bolt 10.

(8) The anchor bolt 10 has a neck 25, which is located adjacent to and rearwards of the wedge body 12. The displaceable body 30 at least partly surrounds this neck 25, at least before installation the expansion anchor. At the neck 25, the diameter of the anchor bolt 10 can be minimal.

(9) In the present embodiment, the expansion anchor is of the stud type. The anchor bolt 10 has, at the rearward end of the neck 25, a shoulder 17 facing forwards for axially engaging the displaceable body 30 and for advancing the displaceable body 30 forwards. The shoulder 17 and the anchor bolt 10 are monolithic. In the present case, the wedge body 12 is, by way of example, also monolithic with the anchor bolt 10.

(10) In a rear region of the anchor bolt 10, the anchor bolt 10 is provided with a tension-introducing structure 18, here in the form of an outer thread provided on the anchor bolt 10.

(11) At its rear end, the anchor bolt 10 has a, preferably flat, rear face 19 that faces rearwardly, wherein the longitudinal axis 99 penetrates the rear face 19 at a right angle. The expansion anchor has an optically readable code 40, a two-dimensional barcode in the present case, which is located at the rear face 19 of the anchor bolt 10, and which can be read out by a sensor 91 located rearwards of the anchor bolt 10.

(12) In order to protect the optically readable code 40 from hammer blows, the expansion anchor has a code protection protrusion 49, which projects, from the anchor bolt 10, rearwardly over the optically readable code 40, i.e., the code protection protrusion 49 extends further to the rear than the optically readable code 40 and the rear face 19. The code protection protrusion 49 and the anchor bolt 10 are monolithic.

(13) In the present example, the code protection protrusion 49 has the shape of a continuous annulus of constant height h. The maximum height h.sub.max of the annular-shaped code protection protrusion 49, which equals the constant annulus height h, is preferably greater that 0.5 mm, more preferably greater than 0.8 mm. Both the height h and the maximum height h.sub.max are measured in the axial direction, i.e., in the direction of the longitudinal axis 99, starting from the rear face 19 as the reference plane. The code protection protrusion 49 has a maximum radial width w.sub.max that is greater than 0.8 mm.

(14) When the expansion anchor is installed the expansion anchor is inserted, front end first, into a hole in a substrate. This is achieved by hammer blows applied to the rear of the anchor bolt 10. The hammer blows are taken up and transferred to the anchor bolt 10 by the code protection protrusion 49. Since the code protection protrusion 49 extends rearwardly from the rear face 19 of the anchor bolt 10, the code protection protrusion 49 protects the optically readable code 40 applied to the rear face 19 from the hammer blows.

(15) Subsequently, the wedge body 12 is drawn into the front-end region of the displaceable body 30 by pulling the anchor bolt 10 together with the wedge body 12 rearwardly—i.e., in the direction of the transparent arrow shown right of the anchor bolt 10 in FIG. 1—in particular by tightening a nut provided on the tension-introducing structure 18 of the anchor bolt 10. This radially expands the sleeve-shaped displaceable body 30, thereby anchoring the expansion anchor in the substrate.

(16) Since the code protection protrusion 49 does not rearwardly cover the optically readable code 40, i.e., since the optically readable code 40 is optically accessible at the outside of the expansion anchor, the optically readable code 40 can be read-out both before installation and/or after installation of the expansion anchor by a sensor 91 that is located rearwards of the anchor bolt 10.