fastener

Abstract

A fastener comprising a body having a tubular portion and a split portion extending from a lower end of the tubular portion, and longitudinally comprising a tapered section tapering in a direction toward the tubular portion. The fastener further comprises an expansion sleeve annularly surrounding the split portion, wherein the expansion sleeve extends longitudinally to a lower end of the tapered section.

Description

TECHNICAL FIELD

[0001] The present invention relates to fasteners, and more particularly, to fasteners having an expansion sleeve. BACKGROUND

[0002] Fasteners, such as drop-in anchors, are often used to suspend an object, such as a pipe, to a target structure, such as a wall or a ceiling. Drop-in anchors have the advantage of easy installation and providing a flat surface on the target structure after installation, compared to other anchors. Conventional drop-in anchors generally have a tubular body with a threaded hole formed in an upper portion thereof. A lower portion of the drop-in anchor is split into two or more segments annularly surrounding a longitudinal axis of the drop-in anchor. The drop-in anchor is set into the target structure by pressing the drop-in anchor into a pre-formed hole in the target structure, where the hole inner diameter is substantially the same as the outer diameter of the tubular body, and inserting a plug into the threaded hole to outwardly expand the segments to achieve a frictional engagement between outer surfaces of the segments and the walls of the pre-formed hole. However, such conventional drop-in anchors cannot meet the requirements of seismic conditions or cracked concrete, because the segments cannot further expand outwardly after installation.

[0003] US8974163B2 discloses a hybrid drop-in anchor, which is a simple combination of a conventional drop-in anchor and a conventional wedge anchor for meeting the cracked concrete test specification. The anchor body of the hybrid drop-in anchor includes a split base section and an expansion sleeve surrounding the split base section. The expansion sleeve has clip segments that can be outwardly expanded by the split base section. However, as shown in US8974163B2, the expansion sleeve only surrounds the upper portion of the tapered section and the constant diameter neck portion of the split base section, which have a smaller radial expansion than the lower portion of the tapered section and the base end when the plug is set in the anchor. Therefore, a protrusion needs to be formed on the outer surface of the expansion sleeve to achieve a tight engagement between the expansion sleeve and the hole wall. However, such protrusion extending radially outwardly from the outer surface of the expansion sleeve will damage the hole wall when the anchor is hammered into the hole or the expansion sleeve is expanded as the plug is inserted.

[0004] In addition, since the tapered section is partially covered by the expansion sleeve in the longitudinal direction when the anchor is installed, the contact between the lower edge of the expansion sleeve and the side surface of the tapered section, or the friction between the hole wall and the tapered section of the anchor body that is not covered, can block the anchor body from sliding back relative to the expansion sleeve when the anchor is pulled outwardly due to seismic conditions or cracks in the target structure. Therefore, there is uncertainty whether the sustained outward expansion achieved by the smooth relative sliding between the anchor body and the expansion sleeve can be achieved, which poses a safety risk.

[0005] Accordingly, it would be advantageous to provide an alternative fastener having an expansion sleeve. SUMMARY

[0006] In one embodiment, the present application provides a fastener comprising a body having a through-hole formed longitudinally therein. The body includes a tubular portion defining a wall surrounding an upper portion of the through-hole, and a split portion extending from a lower end of the tubular portion. The split portion includes a tapered section tapering in a direction toward the tubular portion. The fastener further includes an expansion sleeve annularly surrounding the split portion, wherein the expansion sleeve extends longitudinally to a lower end of the tapered section.

[0007] In another embodiment, the present application provides a fastener comprising a body having a through-hole formed longitudinally therein. The body includes a tubular portion defining a wall surrounding an upper portion of the through-hole, and a split portion extending from a lower end of the tubular portion. The split portion includes a tapered section tapering in a direction toward the tubular portion, wherein the tapered section defines an outer annular recess around the split portion. The fastener further includes an expansion sleeve annularly surrounding the split portion and at least partially received in the outer annular recess, wherein the expansion sleeve extends longitudinally to a reference plane located between an upper end of the outer annular recess and a lower end of the tapered section, and substantially perpendicular to a longitudinal axis of the body, or beyond the reference plane, wherein a longitudinal distance between the reference plane and the lower end of the tapered section is equal to or less than 15% of a longitudinal distance between the upper end of the outer annular recess and the lower end of the tapered section.

[0008] In another embodiment, the present application provides a fastener comprising a body having a through-hole formed longitudinally therein. The body includes a tubular portion defining a wall surrounding an upper portion of the through-hole, and a split portion extending from a lower end of the tubular portion. The split portion includes a tapered section tapering in a direction toward the tubular portion, wherein the tapered section defines an outer annular recess around the split portion. The fastener further includes an expansion sleeve annularly surrounding the split portion and at least partially received in the outer annular recess, wherein the expansion sleeve extends longitudinally to a reference plane located between an upper end of the outer annular recess and a lower end of the tapered section, and substantially perpendicular to a longitudinal axis of the body, or beyond the reference plane, wherein a longitudinal distance between the reference plane and the lower end of the tapered section is equal to or less than 15% of a longitudinal distance between the upper end of the outer annular recess and the lower end of the tapered section. BRIEF DESCRIPTION OF DRAWINGS

[0009] The present application, together with its objectives and the advantages thereof, will be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

[0010] Figure 1 is a schematic exploded perspective view of a fastener having an expansion sleeve according to an embodiment of the present application;

[0011] Figure 2 is a fastener having an expansion sleeve according to an embodiment of the present application after assemblyFigure 1 a fastener according to an embodiment of the present application;

[0012] Figure 3 is a schematic front view of a body of a fastener according to an embodiment of the present application Figure 1

[0013] Figure 4 is a schematic cross-sectional side view of the body of the fastener of Figure 3 cut away from line A-A according to an embodiment of the present application;

[0014] Figure 5 and 6 are respectively a top plan view and a bottom plan view of a fastener according to an embodiment of the present application Figure 1

[0015] Figure 7 is a schematic front view of a fastener according to an embodiment of the present application Figure 1

[0016] Figure 8 is a schematic cross-sectional side view of the fastener of Figure 7 cut away from line B-B according to an embodiment of the present application;

[0017] Figure 9 is a schematic isometric view of an expanding sleeve partially formed according to an embodiment of the present application;

[0018] Figure 10 is a schematic cross-sectional side view of the fastener of Figure 1 installed into a hole of a target structure according to an embodiment of the present application;

[0019] Figure 11 is a schematic front view of a fastener having an expanding sleeve according to another embodiment of the present application; and

[0020] Figure 12 is a schematic cross-sectional side view of the fastener of Figure 11 cut away from line C-C according to an embodiment of the present application. DETAILED DESCRIPTION

[0021] ​​​The detailed description set forth below of the presently preferred embodiment of the application is intended as a description of the presently preferred embodiment of the application and is not intended to represent the only forms in which the present application can be practiced. It is to be understood that the same or equivalent functions can be accomplished by different embodiments that are included in the spirit and scope of the application. The use of the same reference numbers in different drawings indicates the same or similar elements.

[0022] Referring now to Figure 1 and 2 , there are shown schematic exploded perspective and assembled perspective views of a fastener 100 according to an embodiment of the application. The fastener 100 includes a body 102 having a through-hole 104 formed longitudinally therein. The body 102 includes a tubular portion 106 defining a wall 108 encircling an upper portion of the through-hole 104, and a split portion 110 extending from a lower end of the tubular portion 106 and having a free end distal from the tubular portion 106. In a preferred embodiment, the split portion 110 includes at least two inflatable members 112 annularly encircling a lower portion of the through-hole 104. In a preferred embodiment, the inflatable members 112 extend integrally from the lower end of the wall 108. In a preferred embodiment, two adjacent inflatable members 112 are spaced apart by a gap 113.

[0023] Figure 3 is a schematic front view of the body 102 of a fastener according to an embodiment of the application Figure 1 , and Figure 4 is a schematic cross-sectional side view of the body 102 of Figure 3 cut from line A-A. In a preferred embodiment, the split portion 110 longitudinally includes a tapered section 114 tapering in a direction toward the tubular portion 106. The tapered section 114 is preferably frustoconical. In a preferred embodiment, the tapered section defines an outer annular recess 116 around the split portion 110. In a preferred embodiment, an outer diameter of an upper end of the tapered section 114 is less than an outer diameter of a lower end of the tubular portion 106, which forms the outer annular recess 116. In a preferred embodiment, an outer diameter of a lower end of the tapered section 114 is equal to or less than an outer diameter of the tubular portion 106. In a preferred embodiment, the gap 113 extends longitudinally from the upper end of the tapered section 114 to the free end of the split portion 110.

[0024] In preferred embodiments, the split portion 110 further includes a neck section 118 positioned between the tubular portion 106 and the tapered section 114, wherein the minimum outer diameter of the neck section 118 is less than the outer diameter of the lower end of the tubular portion 106. In preferred embodiments, the height of the neck section 118 is less than the height of the tapered section 114. In preferred embodiments, the height of the neck section 118 is 1 / 8 to 1 / 3 the height of the tapered section 114. In preferred embodiments, the tubular portion 106, the neck section 118, and the tapered section 114 are coaxial and integrally formed. In another preferred embodiment, the tapered section 114 integrally extends directly from the lower end of the tubular portion 106.

[0025] In preferred embodiments, the split portion 110 further includes a base section 120 extending from the lower end of the tapered section 114, wherein the outer diameter of the upper end of the base section is equal to the outer diameter of the lower end of the tapered section 114. In preferred embodiments, the base section 120 is generally cylindrical. In another preferred embodiment, the base section 120 tapers in a direction toward the tapered section 114 at a lesser taper than the taper of the tapered section 114. In preferred embodiments, the base section 120 and the tapered section 114 are coaxial and integrally formed. In preferred embodiments, the height of the base section 120 is 1 / 6 to 1 / 3 the height of the tapered section 114.

[0026] As shown in Figure 4 , the upper portion 122 of the through hole 104 is threaded for engaging a threaded male component, such as a bolt or screw. In preferred embodiments, the lower portion 124 of the through hole 104 tapers in a direction away from the upper portion 122 of the through hole 104 such that the expandable component 112 expands outwardly as the plug is inserted from the upper portion 122 into the lower portion 124 of the through hole. In preferred embodiments, the body 102 is integrally formed from a metal raw material by cold forming or machining.

[0027] Referring back to Figure 1 and 2 , the fastener 100 further includes an expansion sleeve 126 annularly disposed about the split portion 110 and at least partially received in the outer annular recess 116. The expansion sleeve 126 includes an annular portion 128 annularly surrounding the split portion 110, and a plurality of expansion segments 130 annularly disposed along the annular portion 128 and integrally extending from the annular portion 128 toward the free end of the split portion 110. In preferred embodiments, the annular portion 128 is C-shaped and annularly surrounds the split portion 110.

[0028] Figure 5 and 6 are embodiments according to the present invention Figure 1The fastener is shown in top and bottom view. In a preferred embodiment, the split portion 110 includes four expandable components 112 substantially evenly distributed around the through hole 104. In a preferred embodiment, the expansion sleeve 126 includes four expandable segments 130 substantially evenly distributed around the through hole 104. However, the number of expandable components 112 or expandable segments 130 is not limited to four, and the number of expandable components 112 and expandable segments 130 does not have to be the same.

[0029] Figure 7 This is an embodiment of the present invention. Figure 1 A schematic front view of the fastener. Figure 8 It is cut from line BB according to an embodiment of the present invention. Figure 7 A schematic cross-sectional side view of the fastener. In a preferred embodiment, an expansion sleeve 126 extends longitudinally from the lower end of the tubular portion 106 to the lower end of the tapered section 114, for example, the expansion sleeve 126 extends longitudinally on the tapered section 114. In a preferred embodiment, an expandable section 130 extends longitudinally beyond the lower end of the tapered section 114 and circumferentially surrounds the base section 120 of the split portion 110. In a preferred embodiment, the expansion sleeve 126 longitudinally covers at least one-third of the height of the base section 120. In another preferred embodiment, the expandable section 130 extends longitudinally to the lower end of the base section 120.

[0030] In a preferred embodiment, the expansion sleeve 126 is generally cylindrical. In a preferred embodiment, the outer diameter of the expansion sleeve 126 is not less than the outer diameter of the tubular portion 106. In a preferred embodiment, the radial thickness of the expansion sleeve 126 gradually decreases from the annular portion 128 to the free end of the expandable section 130, and the inner surface of the expansion sleeve 126 is inclined and mates with the side surface of the tapered section 114.

[0031] refer to Figure 9The diagram shows a schematic isometric view of an expansion sleeve 126 partially formed according to an embodiment of the invention. In a preferred embodiment, it is formed by winding a stamped metal strip 200 around a split portion 110 of a body 102. The metal strip 200 is preferably cut from a sheet metal by stamping or punching, wherein a notch 202 with an inverted "U" or inverted "V" shape is formed along the edge of the metal strip 200 by stamping or cutting to form an expandable section 130. In a preferred embodiment, the upper surface 204 of the metal strip 200 is substantially flat, while the opposite lower surface 206 of the metal strip 200 is inclined relative to the upper surface 204, such that the thickness of the metal strip 200 gradually thins from the loop portion 128 to the free end of the expandable section 130. After the metal strip 200 is wound around the split portion 110 to form an expansion sleeve 126, the expansion sleeve 126 is at least partially received in the outer annular groove 116, and the inner surface of the expansion sleeve 126, i.e. the lower surface 206 of the metal strip 200, mates with the side surface of the tapered section 114.

[0032] Return to reference Figure 1 and 2 In another preferred embodiment, the expansion sleeve 126 can also be formed by machining. A crack 132 is formed for clamping the expansion sleeve 126 onto the crack portion 110.

[0033] Figure 10 It is installed in the hole of the target structure 300 according to an embodiment of the present invention. Figure 1 A schematic cross-sectional side view of the fastener 100. When the plug 302 is inserted into the lower portion 124 of the through hole 104, the expansion section 130 of the expansion sleeve 126 expands outward through the expandable member 112. The bolt 304 is threaded into the upper portion 122 of the through hole 104 for suspending an object onto the target structure 300. Figure 10 As shown, the expansion section 130 extends longitudinally to the lower end of the tapered section 114, where a greater expansion force is generated, which enables a tight engagement between the expansion sleeve 126 and the target structure 300.

[0034] Furthermore, since the entire tapered section 114 is longitudinally covered by the expansion sleeve 126, the tapered section 114 is not stopped by the lower edge of the expansion sleeve 126 when the fastener 100 is pulled outward, and there is no significant friction between the body 102 and the bore wall. The smooth relative sliding between the body 102 and the expansion sleeve 126 causes the expansion sleeve 126 to expand permanently, which ensures a reliable locking engagement between the fastener 100 and the target structure 300 in the event of cracks in the target structure 300 or under seismic conditions.

[0035] refer to Figure 11 This shows a schematic front view of a fastener 400 having an expansion sleeve 402 according to another embodiment of the present invention. Similar to...Figure 1 The fastener 100 and the fastener 400 include a body 404 having a tubular portion 406 and a split portion 408, wherein the split portion 408 longitudinally includes a tapered segment 410 that tapers gradually in the direction toward the tubular portion 406.

[0036] Figure 12 It is cut from line CC according to an embodiment of the present invention. Figure 11 A schematic cross-sectional side view of the fastener. A tapered segment 410 defines an outer annular recess 412 around the split portion 408, wherein the expansion sleeve 402 annularly surrounds the split portion 408 and is at least partially received within the recess 412. Similar to... Figure 1 In a preferred embodiment, the split portion 408 of the fastener 100 further includes a neck section 414 between the tubular portion 406 and the tapered section 410, and a base section 416 extending from the lower end of the tapered section 410. In a preferred embodiment, there is a longitudinal distance d between the lower end of the expansion sleeve 402 and the lower end of the tapered section 410 of the split portion 408. In a preferred embodiment, the longitudinal distance d between the lower end of the expansion sleeve 402 and the lower end of the tapered section 410 is equal to or less than 15% of the longitudinal distance h between the upper end of the recess 412 and the lower end of the tapered section 410. In another preferred embodiment, the longitudinal distance d between the lower end of the expansion sleeve 402 and the lower end of the tapered section 410 is equal to or less than 10% of the longitudinal distance h between the upper end of the recess 412 and the lower end of the tapered section 410.

[0037] In a preferred embodiment, the expansion sleeve 402 extends downward to a reference plane 417 located between the upper end of the recess 412 and the lower end of the tapered section 410, and substantially perpendicular to the longitudinal axis of the body 404, or beyond the reference plane 417, wherein the longitudinal distance between the reference plane 417 and the lower end of the tapered section 410 is equal to or less than 15% of the longitudinal distance h between the upper end of the recess 412 and the lower end of the tapered section 410. In a preferred embodiment, the longitudinal distance between the reference plane 417 and the lower end of the tapered section 410 is equal to or less than 10% of the longitudinal distance h between the upper end of the recess 412 and the lower end of the tapered section 410, such that after the plug is inserted into the lower portion 418 of the longitudinal hole 420 of the fastener 400, the lower end of the expansion sleeve 402 extends substantially longitudinally to the lower end of the tapered section 410, or beyond the lower end of the tapered section 410.

[0038] The preferred embodiments of the invention have been described for illustrative and descriptive purposes, but are not intended to be exhaustive or to limit the invention to the forms disclosed. Those skilled in the art will understand that changes can be made to the above embodiments without departing from their broad inventive spirit. Therefore, it should be understood that the invention is not limited to the specific embodiments disclosed, but covers modifications within the spirit and scope of the invention as defined by the appended claims.

Claims

1. A fastener, comprising: A body having a through hole formed longitudinally therein, comprising: The tubular portion defines a wall surrounding the upper part of the through-hole, and A split portion, extending from the lower end of a tubular portion, having a free end opposing the tubular portion, wherein the split portion longitudinally includes a tapered segment that tapers gradually in the direction toward the tubular portion, the split portion also including a base segment extending from the lower end of the tapered segment, wherein the base segment is cylindrical, or tapers gradually in the direction toward the tapered segment, the taper of the base segment being smaller than the taper of the tapered segment, and the outer diameter of the upper end of the base segment being equal to the outer diameter of the lower end of the tapered segment; and An expansion sleeve, which annularly surrounds the split portion, wherein the expansion sleeve extends longitudinally beyond the lower end of the tapered section, extending at most to the free end of the split portion, thereby enabling smooth relative sliding between the body and the expansion sleeve when the fastener is pulled out of the hole in which it is installed.

2. The fastener of claim 1, wherein the tapered section defines an outer annular recess surrounding the split portion, and the expansion sleeve is at least partially received in the outer annular recess.

3. The fastener of claim 1, wherein the expansion sleeve comprises an annular portion surrounding the body, and a plurality of expansion segments arranged along the annular portion and extending from the annular portion toward the lower end of the tapered section, wherein the split portion comprises at least two expandable members annularly surrounding the lower portion of the through hole, and the expansion segments are expandable outward by the expansion of the expandable members.

4. The fastener according to claim 1, wherein the outer diameter of the upper end of the tapered section is smaller than the outer diameter of the lower end of the tubular section.

5. The fastener of claim 4, wherein the split portion further comprises a neck section located between the tubular portion and the tapered segment, wherein the minimum outer diameter of the neck section is smaller than the outer diameter of the lower end of the tubular portion.

6. The fastener of claim 1, wherein the expansion sleeve extends longitudinally to the lower end of the base section.

7. The fastener of claim 1, wherein the expansion sleeve is cylindrical, and the inner surface of the expansion sleeve is inclined inward and mates with the side surface of the tapered section.

8. The fastener of claim 1, wherein the expansion sleeve includes a longitudinal slit.

9. The fastener of claim 1, wherein the expansion sleeve is formed by rolling up a stamped metal strip around the split portion.

10. A fastener, comprising: A body having a through hole formed longitudinally therein, comprising: The tubular portion defines a wall surrounding the upper part of the through-hole, and A split portion, extending from the lower end of a tubular portion, having a free end opposing the tubular portion, wherein the split portion longitudinally includes a tapered segment that tapers gradually in the direction toward the tubular portion, the split portion also including a base segment extending from the lower end of the tapered segment, wherein the base segment is cylindrical, or tapers gradually in the direction toward the tapered segment, the taper of the base segment being smaller than the taper of the tapered segment, and the outer diameter of the upper end of the base segment being equal to the outer diameter of the lower end of the tapered segment; and An expansion sleeve, which annularly surrounds the split portion, wherein after the plug is placed in the lower part of the through hole, the expansion sleeve extends longitudinally beyond the lower end of the tapered section, extending at most to the free end of the split portion, thereby enabling smooth relative sliding between the body and the expansion sleeve when the fastener is pulled out of the hole in which it is installed.

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