Method for Optically Rating a Fastener Arrangement Including a Screw

Abstract

A method for rating a fastener arrangement that includes a mineral substrate having a hole and a screw which is disposed in the hole, includes unscrewing the screw out of the hole, following the unscrewing, optically inspecting the hole for presence or absence of grout in the hole, and rating the hole as satisfactory when grout has been optically detected in the hole and rating the hole as unsatisfactory when grout has not been optically detected in the hole.

Claims

1.-6. (canceled)

7. A method for rating a fastener arrangement that includes a mineral substrate having a hole and a screw which is disposed in the hole, comprising the steps of: unscrewing the screw out of the hole; following the unscrewing, optically inspecting the hole for presence or absence of grout in the hole; and rating the hole as satisfactory when grout has been optically detected in the hole and rating the hole as unsatisfactory when grout has not been optically detected in the hole.

8. The method according to claim 7, further comprising the step of: following the optically inspecting, screwing the screw back into the hole.

9. The method according to claim 8, wherein the screw has a thread that engages with a mating thread in the mineral substrate when the screw is disposed in the hole and during the step of screwing the screw back into the hole.

10. The method according to claim 7, wherein the screw has a head.

11. The method according to claim 7, wherein a ratio of a diameter of a thread of the screw to a pitch of the thread is between 1 and 2.

12. A method for installing a screw in a hole in a mineral substrate, comprising the steps of: placing grout in the hole; following the placing, screwing the screw into the hole; following the screwing, unscrewing the screw out of the hole; following the unscrewing, optically inspecting the hole for presence or absence of grout in the hole; and rating the hole as satisfactory when grout has been optically detected in the hole and rating the hole as unsatisfactory when grout has not been optically detected in the hole.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIGS. 1 to 7 show, in side view, consecutive steps of an example of a method for installing a screw in a hole in a mineral substrate, including a method for rating a fastener arrangement and/or the screw.

DETAILED DESCRIPTION OF THE DRAWINGS

[0027] First, and as shown in FIG. 1, a hole 90 is provided in a substrate 6. The substrate 6 is preferably a concrete substrate, and the hole 90 can be a blind hole, that can for example be provided by drilling.

[0028] Subsequently, and as shown in FIG. 2, a quantity of hardenable grout 20 is placed in the hole 90. This can for example be done by injecting the grout into the hole 90 using a dispenser or by placing a cartridge containing the hardenable grout 20 in the hole 90. If a cartridge is used, the hardenable grout 20 can be a two component hardenable grout. In particular, the hardenable grout 20 can be a mortar.

[0029] An attachment part 4 is arranged at the surface of the substrate 6 surrounding the hole 90, so that an opening in the attachment part 4 is aligned with the hole 90. This can be done after placing, during placing or, as shown by way of example here, before placing the hardenable grout 20 in the hole 90.

[0030] As shown in FIG. 3, a screw 10 is then provided, which has a shaft 12 defining a longitudinal axis 99 and a thread 13 arranged on the shaft 12 and helically surrounding the shaft 12 and the longitudinal axis 99. The screw 10 is a tapping screw, which means that the screw 10, in particular its thread 13, is able to cut the substrate 6 and to form a mating thread 63 in the substrate 6. The screw 10 has a drive for imparting screw torque on the screw 10. In the present case, the drive is a head 11, in particular a hex-head.

[0031] The screw 10 is screwed into the hole 90, around the longitudinal axis 99, and in this connection, the thread 13 of the screw 10 forms a mating thread 63 in the substrate 6 in the wall of the hole 90.

[0032] As the screw 10 is lowered into the hole 90, it displaces hardenable grout 20, causing hardenable grout 20 to flow alongside the shaft 12 of the screw 10 towards the mouth of the hole 90. The hardenable grout 20 forms a liner 22 there, covering the wall of the hole 90. The screw 10 is screwed into the hole 90 until the head 11 of the screw 10, directly or via for example a washer, abuts on the attachment part 4, resulting in the configuration shown in FIG. 4.

[0033] The hardenable grout 20 of the liner 22 hardens and the liner 22 made up of the hardened grout 20 can improve performance of the screw 10. It is therefore of interest if the liner 22 is present as intended. However, since the head 11 of the screw 10 covers the hole 90 in the substrate 6, presence of the liner 22 cannot be easily determined visually. A dedicated method for rating the screw 10 either “satisfactory” or “unsatisfactory” is therefore employed.

[0034] This method includes, as illustrated in FIG. 5, an unscrewing step, in which the screw 10 is screwed backwards, out of the hole 90, and, as shown in FIG. 6, an inspection step, in which the hole 90 is optically inspected for presence or absence of the grout liner 22 in the hole 90, and an evaluation step, in which the hole 90 is rated “satisfactory” if the grout liner 22 has been detected in the inspection step and “unsatisfactory” otherwise. Optical inspection is carried out using eye vision here.

[0035] As shown in FIG. 7, a re-installation step is then carried out, in which the screw 10 is screwed back into the hole 90, with the thread 13 following the already-existing mating thread 63.