Screw expansion sleeve

Abstract

The utility model discloses a screw expansion sleeve which comprises a base portion capable of allowing a screw to penetrate through, three expansion pieces extending in the axial direction are arranged at one end of the base portion, and an inner cavity for containing the screw is defined by the base portion and the three expansion pieces. The radial section of the base portion is oval, axial protruding ribs are arranged on the peripheral wall of the base portion, and the expansion piece is provided with an anti-skid protruding portion. When a screw is installed and hit, the three expansion pieces can enable the outer diameter of the expansion sleeve to be expanded to be larger, the expansion sleeve is fixed to a wall body more tightly, and the arrangement of the anti-skidding protruding portions on the outer walls of the expansion pieces and the axial protruding ribs on the base portion can prevent the expansion sleeve from rotating and slipping in the wall body when the screw is hit. And the installation firmness between the expansion sleeve and the wall body and between the expansion sleeve and the screw is obviously improved.

Description

Technical Field

[0001] The utility model relates to a screw expansion sleeve and belongs to the technical field of hardware auxiliary parts. Background Art

[0002] The existing screw expansion sleeves on the market have the same outer diameter at the head and tail ends. Sometimes when encountering a wall, the holes made when drilling are of different sizes. When installing the expansion sleeve, some holes can be installed, some holes slip, and some holes cannot be completely installed. There are also holes made on foam brick walls and hollow brick walls. The surface of the wall hole is 1-1.5 cm hard cement board, and the inside of the hole is full of soft bricks, which is easy to slip during installation. Utility Model Content

[0003] The utility model aims to solve the problems of the prior art and provide a screw expansion sleeve which is firmly installed and not easy to slip.

[0004] The purpose of this utility model is achieved through the following technical solutions:

[0005] A screw expansion sleeve is characterized by comprising a base capable of accommodating the screw passing therethrough, one end of the base being provided with three axially extending expansion sheets, and the base and the three expansion sheets forming an inner cavity for accommodating the screw.

[0006] The screw expansion sleeve as described above is characterized in that the radial cross-section of the base is elliptical.

[0007] The screw expansion sleeve as described above is characterized in that the peripheral wall of the base is provided with axial ribs.

[0008] The screw expansion sleeve as described above is characterized in that the expansion piece is provided with an anti-slip convex portion.

[0009] The screw expansion sleeve as described above is characterized in that at least one side of each expansion piece is provided with a rack bent toward the inner cavity.

[0010] The screw expansion sleeve as described above is characterized in that the rack is arranged axially along the expansion piece, and the rack gradually widens from the base end to the other end of the expansion piece.

[0011] A screw expansion sleeve as described above is characterized in that the base and the expansion sheet are integrally formed of metal, the base is axially provided with an open groove, the three expansion sheets form an elliptical hollow column, the outer diameter of the base is larger than the outer diameter formed by the three expansion sheets, and the anti-slip protrusion is a transverse rib.

[0012] The screw expansion sleeve as described above is characterized in that the base and the expansion piece are integrally formed of plastic, the inner cavity gradually narrows from the base end to the free end of the expansion piece, and the anti-slip convex portion is a longitudinal convex rib.

[0013] The screw expansion sleeve as described above is characterized in that a guide portion is provided at the extending end of the expansion piece, and the guide portion is in the shape of a truncated cone.

[0014] A screw expansion sleeve as described above is characterized in that the axial ribs include outer ribs arranged on the outer circumferential wall and inner ribs arranged on the inner circumferential wall, the outer ribs extend to form anti-slip protrusions on the outer wall of the expansion piece, the height of the inner ribs is greater than the height of the outer ribs, and the inner ribs extend axially from the base to the guide portion.

[0015] Compared with the prior art, the utility model has the following advantages:

[0016] The utility model adopts three expansion pieces to form a screw expansion sleeve. When installing and screwing, the three expansion pieces can make the outer diameter of the expansion sleeve expand larger and more tightly fixed to the wall. The anti-skid convex part of the outer wall of the expansion piece and the outer convex rib of the base can prevent the expansion sleeve from rotating and slipping in the wall when the screw is driven in; the rack of the metal expansion piece bent toward the inner cavity and the inner convex rib of the inner wall of the plastic expansion sleeve can bite more tightly with the corresponding screw to prevent the screw from slipping in the expansion sleeve. The utility model significantly improves the installation firmness between the expansion sleeve and the wall and the screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is one of the three-dimensional structural schematic diagrams of Example 1;

[0018] Figure 2 The third is a schematic diagram of the three-dimensional structure of Example 1;

[0019] Figure 3 It is a bottom view of Example 1;

[0020] Figure 4 is a top view of Example 1;

[0021] Figure 5 This is one of the three-dimensional structural schematic diagrams of Example 2;

[0022] Figure 6 This is the second schematic diagram of the three-dimensional structure of Example 2;

[0023] Figure 7 is a top view of Example 2;

[0024] Figure 8 This is a bottom view of Example 2. DETAILED DESCRIPTION

[0025] The utility model will be further described in detail below in conjunction with the accompanying drawings.

[0026] like Figure 1-8 As shown, a screw expansion sleeve comprises a base 1 capable of accommodating the screw passing through, one end of the base 1 is provided with three axially extending expansion sheets 2, and the base 1 and the three expansion sheets 2 surround an inner cavity 3 for accommodating the screw. The expansion sleeve is first driven into the wall, and then the screw is installed into the inner cavity 3 of the expansion sleeve. When the screw enters the inner cavity 3, the three expansion sheets 2 are stretched to make their outer diameters circumferentially larger, and they are firmly in contact with the wall without falling off.

[0027] Furthermore, the outer diameter of the base 1 is set to be elliptical, the radial cross section of the base 1 is elliptical, and it is inserted into the circular mounting hole and fastened without rotation. Preferably, the three expansion sheets 2 form an elliptical hollow column, and the outer wall of the expansion sheet 2 is provided with an anti-slip convex portion 22. Both can strengthen the tightness of the connection between the expansion sleeve and the wall and prevent the expansion sleeve from loosening.

[0028] Preferably, the peripheral wall of the base 1 is provided with an outer convex rib 11, which can further prevent the expansion sleeve from slipping.

[0029] Furthermore, in order to ensure the firm installation of the expansion sleeve and the screw, at least one side of each expansion piece 2 is provided with a rack 21 bent toward the inner cavity 3. The rack 21 is arranged along the axial direction of the expansion piece 2. The rack 21 can engage more with the threads on the outer surface of the screw to prevent the screw from coming out. In order to make the circumferential outer diameter of the three expansion pieces 2 expand more, the base end of the rack 21 is narrow and gradually widens toward the other end of the expansion piece 2. At the same time, the serrations on the rack 21 also engage more tightly with the threads. A specific embodiment of the present utility model, such as Figure 1-4 As shown, the base 1 and the expansion piece 2 are integrally formed of metal, the base 1 is axially provided with an open groove 12, and the anti-slip convex portion 22 is a transverse convex rib provided on the outer wall of the expansion piece 2. The open groove 12 gives the expansion sleeve a certain elasticity, so that the screw can adapt to the expansion sleeve better and more tightly after installation. Of course, the inner wall of the expansion piece 2 can also be integrally stamped with corresponding transverse ribs to save material costs.

[0030] Another specific embodiment of the utility model is as follows Figure 5-8 As shown, the base 1 and the expansion sheet 2 are integrally formed of plastic, the inner cavity 3 gradually narrows from the base end to the free end of the expansion sheet, and the anti-slip convex portion 22 is a longitudinal convex rib. When the screw is driven in, it is installed more tightly with the expansion sleeve, the expansion sleeve expands more, and the installation with the wall is tighter. Preferably, in order to allow the expansion sleeve to be installed in the hole on the wall, a guide portion 23 is provided at the insertion end of the expansion sheet 2, and the guide portion 23 is surrounded by a truncated cone shape, and its free end is narrowed, which is easier to install in the wall hole.

[0031] In order to further tighten the installation tightness between the screw and the expansion sleeve, the axial rib 11 on the peripheral wall of the base 1 includes an outer rib 111 arranged on the outer peripheral wall and an inner rib 112 arranged on the inner peripheral wall. For the plastic expansion sleeve, the outer rib 111 extends to form an anti-slip convex portion 22 on the outer wall of the expansion piece 2. The height of the inner rib 112 is greater than the height of the outer rib 111. The inner rib 112 extends axially from the base 1 to the guide portion 23, radially increasing the thickness of the expansion sleeve, improving the strength of the expansion sleeve, and preventing the screw from slipping in the expansion sleeve.

[0032] When the utility model is used, a mounting hole is first punched on the wall, and then the expansion sleeve is installed into the mounting hole so that the base 1 faces outward and is flush with the wall surface. Then, a screw is installed into the expansion sleeve so that the screw and the expansion sleeve are tightly connected and fastened in the wall mounting hole.

Claims

1. A screw expansion sleeve, characterized in that: The invention comprises a base (1) capable of accommodating a screw passing therethrough, wherein one end of the base (1) is provided with three axially extending expansion sheets (2), the base (1) and the three expansion sheets (2) enclose an inner cavity (3) for accommodating the screw, and at least one side of each expansion sheet (2) is provided with a rack (21) bent toward the inner cavity (3).

2. A screw expansion sleeve according to claim 1, characterized in that The radial cross section of the base (1) is elliptical.

3. A screw expansion sleeve according to claim 1, characterized in that The peripheral wall of the base (1) is provided with axial convex ribs (11).

4. A screw expansion sleeve according to claim 3, characterized in that The expansion sheet (2) is provided with an anti-slip convex portion (22).

5. The screw expansion sleeve according to claim 1, characterized in that The rack (21) is arranged axially along the expansion sheet (2), and the rack (21) gradually widens from the base end toward the other end of the expansion sheet (2).

6. A screw expansion sleeve according to claim 4, characterized in that The base (1) and the expansion sheet (2) are integrally formed of metal, the base (1) is axially provided with an open groove (12), the three expansion sheets (2) form an elliptical hollow column, the outer diameter of the base (1) is larger than the outer diameter formed by the three expansion sheets, and the anti-slip convex portion (22) is a transverse convex rib.

7. A screw expansion sleeve according to claim 4, characterized in that The base (1) and the expansion sheet (2) are integrally formed of plastic, the inner cavity (3) gradually narrows from the base end to the free end of the expansion sheet, and the anti-slip convex portion (22) is a longitudinal convex rib.

8. A screw expansion sleeve according to claim 7, characterized in that The extending end of the expansion sheet (2) is provided with a guide portion (23), and the guide portion (23) is in the shape of a truncated cone.

9. A screw expansion sleeve according to claim 8, characterized in that The axial convex rib (11) comprises an outer convex rib (111) provided on the outer peripheral wall and an inner convex rib (112) provided on the inner peripheral wall, wherein the outer convex rib (111) extends to form an anti-slip convex portion (22) on the outer wall of the expansion sheet (2), the height of the inner convex rib (112) is greater than the height of the outer convex rib (111), and the inner convex rib (112) extends axially from the base (1) to the guide portion (23).

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