RU1830115C - Expansion bolt and method of its attachment - Google Patents

Abstract

Usage: mechanical engineering, fasteners. SUMMARY OF THE INVENTION: the dowel comprises a spacer sleeve 1, a finger in the form of a threaded shank 3 with a spacer cone 4, and an inner sleeve 9. The sleeve 9 is screwed onto the finger and axially moves the sleeve 1 through the protrusion 12; the segnet 2. moving along the cone 4, expands geometrically with the walls of the hole and the dowel is securely fastened. 2 s.p. f-ly, 2 ill.

Description

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The invention relates to mechanical engineering, in particular to expansion dowels fixed in drilled holes that are conically expandable inwardly.

The purpose of the invention is to simplify installation and increase the reliability of fastening.

In FIG. 1 shows an expansion plug in pre-installation states; in FIG. 2 - expansion dowel, fixed in a hole drilled in the masonry wall conically expanded into the hole.

The expansion dowel contains a spacer sleeve 1 with longitudinal slots forming segments 2, and also a finger located in the form of a threaded shank 3 with a spacer cone 4. The sleeve 1 is made with a stepped longitudinal hole 5 forming a step b in the transition zone of the steps and a peripheral groove 7 in the zone of the junction of the body of the sleeve with segments 2. The step of the sleeve with a smaller wall thickness is made with an internal thread 8 on a part of its length from the end to the inside, the hole in the section of the sleeve with a larger wall thickness is made smooth. In the spacer sleeve 1 there is an inner sleeve 9 with an axial threaded hole 10. The sleeve 9 is screwed onto the shank 3 of the finger until it stops against its ends 11 in the ledge 6 of the protrusion 12.

When the expansion bolt shield is installed in a hole drilled in the wall or ceiling masonry 13 and having a conical extension 14 at the back, it is screwed in using the drill, not shown in the drawing, with an impact nozzle in the uncompressed state, shown in FIG. 1. In this case, the percussion device acts on the inner sleeve 9, which abuts with its end 11 to the protrusion 12. When the finger abuts the end 15 of the cone in the bottom of the hole, the inner sleeve 9. is provided with an internal thread 10, is screwed onto a shank 3 made with an external thread and through the protrusion 12 presses on the spacer sleeve 1, which, while moving, is axially guided by its spacer segments 2 along the cone 4 of the finger. In this case, a geometric closure occurs by inserting the spacer segments 2 into the bore of the hole, and due to the peripheral groove, the expansion of the spacer segments is ensured. The walls of the spacer sleeve can have only a small thickness, due to which, with the smallest possible outer diameter of the spacer sleeve, a large diameter of the inner hole provided with an internal thread is achieved. Due to this, the standard thread of a larger diameter does not cause

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an increase in the outer diameter of the spacer sleeve, since it does not even provide a thrust surface for the percussion instrument.

Geometric expansion of the spacer segments made on the spacer sleeve in the drilled hole with an extension at the rear end is achieved by screwing the inner sleeve into the spacer sleeve, as well as by screwing the inner sleeve onto the finger. Thus, this expansion is achieved due to the torque, and not due to clogging. Due to this, it is possible to eliminate the disadvantages expressed in the bursting of the wall masonry caused during installation of the shock-expansion dowel by means of clogging it.

Since the enlarged diameter of the inner hole in the expansion plug according to the invention does not simultaneously determine the need to increase the outer diameter of the expansion sleeve, since there is no need to provide an impact surface on the expansion sleeve, the wall thickness of the expansion sleeve can be reduced to a minimum. Along with the advantage of saving material, this leads to the fact that screws with an increased diameter can be inserted into the dowel after being installed without using the dowel with a correspondingly large outer diameter.

The full fit of the expanded spacer segments of the spacer sleeve in the expansion zone in the drilled hole is ensured by the fact that the inner sleeve is screwed onto the external thread of the finger, and the spacer sleeve with its spacer segments is guided along the cone of the bolt, because the inner sleeve with its end facing the cone rests on the surface of the protrusion made under a circular groove defining the spacer segments.

The inner sleeve may be made of soft material or other, preferably deformable, material so that it can fit onto the tooth bolt or otherwise profiled bolt and firmly fasten to it.

Claims (1)

1. An expansion dowel for fastening in drilled holes, which are conically expanded inward, comprising a spacer sleeve with longitudinal splines in its expandable part forming spacer segments, a peripheral groove in the joint area of the sleeve body with spacer segments and a stepped longitudinal hole forming a step in the transition zone of the steps as well as a finger in the form of a threaded shank with a spacer cone at one end, placed in the hole of the sleeve. With the possibility of its stop in the bottom of the drilled hole, while the step of the sleeve with a larger wall thickness is made in the area under the peripheral groove, a step with a smaller wall thickness is made on the side opposite to the spacer segments, and has a thread part of its length from the end to the inside, characterized in that it is provided with an internal sleeve with an axial threaded hole located in the hole of the spacer sleeve in the area with a smaller wall thickness and screwed onto the shank of the finger all the way into the ledge, and " eleven to 10 fifteen the hole in the section with a larger wall thickness is made smooth. 2, A method of securing a spacer dowel in drilled holes that are conically expanded inwardly, comprising placing the spacer dowel in the drilled hole until the end surface of the finger cone abuts against the bottom of said hole and moving the spacer sleeve until it expands and seizes the segments between the spacer cone and the walls of the hole, the fact that the spacer sleeve is axially moved by screwing the inner sleeve onto the threaded shank of the finger when the end face of the latter contacts the step, User 1 b FIG. 2