Blind nut

A blind nut mountable in mounted members such as panels of a wide range of thicknesses. The blind nut includes an internal threading portion, a hollow tube-shaped portion adjacent to the threading portion, and an open flange formed in the tube-shaped portion on the end opposite the internal threading. The internal threading portion and the tube-shaped portion are inserted into a mounting hole in a mounted member, and a section of the tube-shaped portion is plastically deformed to enlarge the diameter in order to grip the mounted member between the deformed enlarged-diameter portion and the flange, and mount the blind nut in the mounted member. The tube-shaped portion has a tapered portion adjacent to the internal threading portion, and a cylindrical straight portion adjacent to the flange. The tapered portion and the straight portion are plastically deformed to widen their diameter and mount the blind nut on the mounted member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority, under 35 U.S.C. §119(a)-(d), to JP Patent Application No. 2012-106478 filed May 8, 2012, the contents of which are incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a blind nut. The present invention relates more specifically to a blind nut that can be mounted in mounted members such as panels having a wide range of thicknesses.

BACKGROUND OF THE INVENTION

A blind nut includes an internal threading portion, a tube-shaped portion continuing from the internal threading portion, and a flange at the end of the tube-shaped portion. A blind nut is inserted into a hole in a mounted member and a fastening tool is used to cause the tube-shaped portion to buckle, expanding the diameter of the tube-shaped portion, interposing the mounted member between the buckled tube-shaped portion and the flange, and securing the blind nut to the mounted member. The external threading of a bolt can then be screwed into the internal threading portion of the blind nut to secure another mounted member. Because a blind nut can be used from one side of a mounted member, it can be used to fasten a nut to a mounted member such as a panel whose opposite side can be difficult to reach.

FIG. 1is a front view, including a partially cut away cross-sectional view, showing a blind nut10of the prior art. The blind nut10is cylindrical and is axially symmetrical the entire length along a central axis. An internal threading portion11is provided at one end. The internal threading portion11is cylindrical, and internal threading15is formed inside. The external threading of a fastening tool can be screwed into the internal threading15. The tube-shaped portion13continuing from the internal threading portion11is cylindrical, and is thinner than the internal threading portion11. This portion buckles when the blind nut is mounted on a mounted member41. The blind nut10has a flange14at the end opposite the internal threading portion11. The outer diameter of the flange14is greater than the inner diameter of the mounting hole43in the mounted member41so that, when the blind nut10is inserted into the mounting hole43in the mounted member41, the bottom surface of the flange14comes into contact with the upper surface of the mounted member41and stops. A through-hole16is formed from the side end portion of the flange14to the internal threading portion16. The inner diameter of the through-hole16is constant from the side end portion of the flange14to the tube-shaped portion13, and the inner diameter becomes smaller in the internal threading portion11.

FIG. 2is a front view, including a partially cut away cross-sectional view, showing the blind nut10mounted in the mounting hole43of a mounted member41. When the blind nut10is mounted using a fastening tool, the thin tube-shaped portion13buckles to become an enlarged-diameter portion17, the mounted member41is interposed between the enlarged-diameter portion17and the flange14, and the blind nut10is mounted in the mounted member41.

The length of the tube-shaped portion13is often changed so that a single type of blind nut can be mounted in mounted members with a wide range of thicknesses. When the length of the tube-shaped portion13is too long relative to the thickness of the mounted member41and the blind nut10is mounted, the thin tube-shaped member13does not buckle uniformly to become an enlarged-diameter portion17with a uniform diameter around the entire circumference. A section of the enlarged-diameter portion17buckles inwardly, the enlarged-diameter portion17does not come into contact with the mounted member, and an abnormally deformed portion is likely to be formed which rises up from the surface of the mounted member.

In order to mount a blind nut in mounted members of different thicknesses without abnormally deformed portions being formed, many different types of blind nut have to be prepared with tube-shaped portions of varying lengths. Thus, a single type of blind nut that can be easily mounted in mounted members with a wide range of thicknesses, such as panels, is desired.

A blind nut is disclosed in Patent Document 1 which has an internal threading portion, a hollow tube-shaped portion, and a flange. This thick blind nut, which has a wide outer diameter, is inserted into a hole in a panel, and the tube-shaped portion is buckled to fix the blind nut in the panel using the buckled tube-shaped portion and the flange. The outer diameter of the tube-shaped portion becomes gradually smaller towards the internal threading portion. The blind nut in Patent Document 1 is problem-free because the position in the tube-shaped portion where the buckling begins is determined beforehand. The position where the blind nut begins to become deformed is the position corresponding to the surface of the mounted member or a position in the tube-shaped portion adjacent to the internal threading portion. However, the blind nut in Patent Document 1 cannot be fastened to mounted members with a wide range of thicknesses.

A blind nut is disclosed in Patent Document 2 which as an internal threading portion, a hollow tube-shaped portion, and a flange. This blind nut is inserted into a hole in a panel, and the tube-shaped portion is buckled to fix the blind nut in the panel using the buckled tube-shaped portion and the flange. In this blind nut, the tube-shaped portion has a cylindrical portion that is thinner than the internal threading portion, and a compressed-diameter portion formed between the cylindrical portion and the internal threading portion. When this blind nut is fastened, the tube-shaped portion begins to bend at the compressed-diameter portion. However, the length of the compressed-diameter portion is short, so the blind nut in Patent Document 2 cannot be fastened to mounted members with a wide range of thicknesses.

Therefore, a single type of blind nut is desired that can be easily mounted in mounted members such as panels having a wide range of thicknesses. Also desired is a blind nut having a tube-shaped portion whose diameter can be sufficiently enlarged to ensure reliable mounting in a mounted member.

PRIOR ART DOCUMENTS

BRIEF SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a single type of blind nut that can be easily mounted in mounted members such as panels having a wide range of thicknesses. Another object of the present invention is to provide a blind nut having a tube-shaped portion whose diameter can be sufficiently enlarged to ensure reliable mounting in a mounted member.

In order to achieve these objects, the present invention has a tube-shaped portion whose diameter is enlarged, and this tube-shaped portion has a cylindrical straight portion, and a tapered portion between the straight portion and the internal threading portion. Here, the diameter of the boundary portion between the straight portion and the tapered portion is enlarged. Buckling problems are less frequent when this blind nut is mounted, whether mounted in a thin-panel mounted member or in a thick-panel mounted member.

One aspect of the present invention is a blind nut including an internal threading portion having internal threading formed on the inside, a hollow tube-shaped portion adjacent to the threading portion, and an open flange formed in the tube-shaped portion on the end opposite the internal threading. The internal threading portion and the tube-shaped portion are inserted into a mounting hole in a mounted member, and a section of the tube-shaped portion is plastically deformed to enlarge the diameter. This grips the mounted member between the deformed enlarged-diameter portion and the flange, and mounts the blind nut in the mounted member. The blind nut in this aspect of the present invention is characterized by a tube-shaped portion having a cylindrical straight portion adjacent to the flange, and a tapered portion which becomes gradually narrower from the straight portion towards the internal threading portion.

Because the diameter of the boundary portion between the straight portion and the tapered portion is enlarged, the position at which the diameter begins to be enlarged is constant, and the blind nut is reliably secured to the mounted member without buckling problems occurring. Because the boundary portion is plastically deformed so that the outer diameter of the enlarged-diameter portion is sufficiently enlarged, the release strength is high, and the blind nut is reliably secured.

Preferably, the straight portion and the tapered portion have the same thickness. In this way, the diameter of the boundary portion between the straight portion and the tapered portion can be enlarged to the same extent vertically.

The angle of the tapered portion relative to the straight portion is from 1 to 20°. The angle is preferably from 2 to 15°. The angle is more preferably from 3 to 8°. A smaller tapering angle ensures a tapered portion of sufficient length.

Preferably, the blind nut is within the range of 0.09x1+0.15<y1<0.35x1+1.5, when the outer diameter of the straight portion is x1(mm) and the length of the section of the straight portion protruding from the mounted member is y1(mm). When the length of the straight portion is within this range, buckling does not occur.

Preferably, the blind nut is within the range of 0.22x2+0.4<y2<0.45x2+1.4, when the length of the straight portion is x2(mm) and the length of the tapered portion is y2(mm). When the length of the tapered portion is within this range, buckling does not occur.

The present invention provides a single type of blind nut that can be easily mounted in mounted members such as panels having a wide range of thicknesses. The present invention can also provide a blind nut having a tube-shaped portion whose diameter can be sufficiently enlarged to ensure reliable mounting in a mounted member.

DETAILED DESCRIPTION OF THE INVENTION

The following is an explanation with reference to the figures of a blind nut20according to an embodiment of the present invention.FIG. 3is a front view, including a partially cut away cross-sectional view, showing a blind nut20in an embodiment of the present invention. The blind nut20is cylindrical and axially symmetrical with respect to the center line along its entire length. It has an internal threading portion21on one end. The internal threading portion21is cylindrical and has internal threading25formed on the inside. The external threading of a fastening tool is screwed into the internal threading25. After the blind nut20has been mounted, the external threading of a bolt can be screwed in to mount another mounted member.

The blind nut20has a tube-shaped portion adjacent to the internal threading portion21. The tube-shaped portion has a tapered portion22adjacent to the internal threading portion21, and a cylindrical straight portion23adjacent to the tapered portion22. The tapered portion22has a constant thickness and is thinner than the internal threading portion21. The outer diameter and the inner diameter become gradually larger in the upward direction (thickness t23, length l22). The straight portion23adjacent to the tapered portion22is cylindrical and has a constant thickness, which is the same as that of the tapered portion22(thickness t23, length l23, outer diameter D23). The section of the straight portion23protruding from the mounting hole43in the mounted member41and the tapered portion22buckle when the blind nut is mounted in the mounted member41. The blind nut20has a flange24adjacent to the straight portion23on the end opposite the internal threading portion23. The outer diameter of the flange24is greater than the outer diameter of the straight portion23, and greater than the inner diameter of the mounting hole43in the mounted member41.

When the blind nut20is inserted into the mounting hole43in the mounted member41with the internal threading portion21at the front, the bottom surface of the flange24comes into contact with the upper surface of the mounted member41and stops. A through-hole26is formed from the flange24end to the internal threading portion21end. The inner diameter of the through-hole26is constant from the flange24end to the straight portion23, and the inner diameter becomes gradually smaller towards the internal threading portion21in the tapered portion22. The inner diameter of the internal threading portion21is constant but even smaller, and internal threading25is formed on the inner surface. InFIG. 3, the outer diameter of the straight portion23is constant, but the outer diameter of the tapered portion22becomes gradually smaller towards the internal threading portion21.

FIG. 4andFIG. 5are diagrams showing the fastening tool used in the present embodiment.FIG. 4is a perspective view of the entire fastening tool50used in the present embodiment. The fastening tool50uses compressed air as its power source, and has a nosepiece52adjacent to the main body portion51for supporting the component to be fastened, and a screw mandrel53with external threading at the tip. A rotating body (not shown) is rotated, and the screw mandrel53at the tip is rotated in the forward or reverse direction to engage or disengage from internal threading. The component can be pushed in strongly without rotating the screw mandrel53.

FIG. 5is a front view of the tip of the fastening tool50used in the present invention. The main body portion51of the fastening tool50has a nosepiece52which is pressed against the mounted member. The bottom surface of the nosepiece52is flat. A column-shaped screw mandrel53having external threading formed on the outer circumference extends forward (downward inFIG. 5) at the center of the nosepiece52.

The outer diameter of the screw mandrel53is smaller than the inner diameter of the through-hole26in the tapered portion22and the straight portion23of the blind nut20so that it can be inserted into the through-hole26. The external threading of the screw mandrel53has an external diameter that allows it to be screwed into the internal threading25in the internal threading portion21of the blind nut20. The fastening tool50rotates the screw mandrel53in the forward or reverse direction to engage or disengage the internal threading25of the internal threading portion21. The flange24of the blind nut20can be supported by the nosepiece52to strongly push in the blind nut without rotating the screw mandrel.

The following is an explanation of the operation performed to mount the blind nut20in the mounted member41with reference toFIG. 6throughFIG. 9.FIG. 6is a front view, including a partially cut away cross-sectional view, showing the blind nut20set in the mounting hole43of a mounted member41(thickness t41). The blind nut20is inserted into the mounting hole43in the mounted member41from the internal threading portion21until the bottom surface of the flange24comes into contact with the upper surface of the mounted member41.

FIG. 7is a front view, including a partially cut away cross-sectional view, showing the mounting tool50set and the blind nut in the process of being mounted. The screw mandrel53is passed through the through-hole26of the blind nut20, and the screw mandrel53is rotated in the forward direction to screw the external threading of the screw mandrel53into the internal threading25of the internal threading portion21. When the external threading of the screw mandrel53has been screwed into the internal threading25to a predetermined distance, the bottom surface of the nosepiece52of the fastening tool50comes into contact with the upper surface of the flange24of the blind nut20, and rotation of the screw mandrel53stops.

With the bottom surface of the nosepiece52of the fastening tool50in contact with and supported by the flange24of the blind nut20, the screw mandrel53is strongly pushed towards the main body portion51without rotating. At this time, the bottom surface of the nosepiece52pushes the flange24of the blind nut20downward to provide support, and the screw mandrel53pulls the internal threading portion21upwards.FIG. 7is a front view, including a partially cut away cross-sectional view, showing the tapered portion22of the blind nut20and a section of the straight portion23(the section protruding downward from the mounting hole43in the mounted member41) being buckled and plastically deformed so as to expand their diameters.

Because the outer diameter of the straight portion23inside the mounting hole43of the mounted member41is restricted by the mounting hole43, the diameter is as large as the inner diameter of the mounting hole43and cannot expand any further.

The diameter of the section of the straight portion23protruding downward from the bottom surface of the mounted member41is expanded and comes into contact with the bottom surface of the mounted member41surrounding the mounting hole43.FIG. 8is a front view, including a partially cut away cross-sectional view, showing further plastic deformation of the tapered portion22and the straight portion23. This portion becomes the enlarged-diameter portion27, and the mounted member41is interposed and secured by the enlarged-diameter portion27and the flange24.

After the fastening tool50has completed the fastening process, the screw mandrel53is rotated in the reverse direction fromFIG. 7, and the external threading of the screw mandrel53is unscrewed from the internal threading25of the internal threading portion21. After the threading has been unscrewed, the fastening tool50is moved upward.FIG. 9is a front view, including a partially cut away cross-sectional view, showing the mounted blind nut20. Here, the fastening tool50has been removed from the mounted member41in which the blind nut20has been mounted.

FIG. 10is a front view, including a partially cut away cross-sectional view, showing another mounted member42having been mounted, using a bolt, in the blind nut20mounted in the mounted member41shown inFIG. 9. A bolt45is prepared having a head portion46and a shaft portion47. The external threading of the shaft portion47can be screwed into the internal threading25of the internal threading portion21of the blind nut20. The through-hole26in the blind nut20is aligned with the mounting hole44in the other mounted member42, and the mounted member42is arranged above the flange24of the blind nut20. The shaft portion47of the bolt45is passed through the mounting hole44of the other mounted member42, and inserted into the through-hole26in the blind nut20. The external threading of the shaft portion47of the bolt45is screwed into the internal threading25of the internal threading portion21of the blind nut20, and the other mounted member42is mounted in the blind nut20. InFIG. 10, the other mounted member42is mounted on the flange24side of the blind nut20. However, the other mounted member42can also be mounted on the internal threading portion21side of the blind nut20(not shown), which is on the opposite side ofFIG. 10(the bottom side inFIG. 10).

A mounting operation simulation was performed using the finite element method. In this simulation, a blind nut10of the prior art inFIG. 1with a long tube-shaped portion13(straight portion, outer diameter D13=10 mm, length l13=9.5 mm), and a blind nut20of the present embodiment inFIG. 3with a straight portion23(length l23=7.1 mm, outer diameter D23=10 mm) and a tapered portion22(length l22=4.6 mm) were mounted in a thin mounted member41(panel thickness t24s=3.3 mm) and a thick mounted member41(panel thickness t24l=5.5 mm).FIG. 11(a) shows the blind nut10of the prior art mounted in the thin mounted member41s.FIG. 11(b) shows the blind nut10of the prior art mounted in the thick mounted member41l. When mounted in a thin mounted member41sas shown inFIG. 11(a), the enlarged-diameter portion17rises up from the bottom surface of the mounted member41sas it buckles. When mounted in a thick mounted member41las shown inFIG. 11(b), the enlarged-diameter portion17makes contact with the bottom surface of the mounted member41land is properly mounted.

FIG. 12(a) shows the blind nut20of the present embodiment mounted in the thin mounted member41s.FIG. 12(b) shows the blind nut20of the present embodiment mounted in the thick mounted member41l. When mounted in a thin mounted member41sas shown inFIG. 12(a), and when mounted in a thick mounted member41las shown inFIG. 12(b), the enlarged-diameter portion27makes contact with the bottom surface of the mounted member41and is properly mounted. Unlike the blind nut10of the prior art inFIG. 11, the blind nut20of the present embodiment inFIG. 12can be mounted in mounted members41with a wide range of thicknesses.

In the blind nut10of the prior art, which has a cylindrical tube-shaped portion13, the tube-shaped portion13of the blind nut10does not begin to become enlarged at a fixed position when the tube-shaped portion13is too long. As a result, the enlarged-diameter portion tends to rise up off the surface of the mounted member as it buckles. There is no straight portion in the tube-shaped portion with a constant outer diameter, only a tapered portion. As a result, the blind nut begins to become enlarged in diameter on the surface of the mounted member, and the enlarged-diameter portion tends to rise off the surface of the mounted member as it continues to buckle.

When a blind nut20of the present embodiment is used, which has a straight portion23and a tapered portion22, the boundary portion between the tapered portion22and the straight portion23becomes plastically deformed and its diameter is enlarged. Because the boundary portion is below the surface of the mounted portion, the enlarged-diameter portion27develops a sufficiently large outer diameter and does not rise up during buckling. The starting portion for the enlarged diameter is predetermined, and the mounted member41can be reliably secured. When the tapered portion22is sufficiently long, the outer diameter of the enlarged-diameter portion27is increased. As a result, the release strength is high, and the mounted member can be reliably secured.

When the outer diameter of the enlarged-diameter portion27is large, the release strength from the mounted member is increased, and the blind nut can be reliably mounted in the mounted member. When mounted in a mounted member made of plastic or a thin panel made out of metal, the blind nut can be mounted reliably.

The angle of the tapered portion22relative to the straight portion23has to be relatively small, that is, from 1 to 20°. The angle of the tapered portion22is preferably from 2 to 15°, and more preferably from 3 to 8°. The thickness of the tapered portion22and the straight portion23is preferably the same. In this way, the diameter of the boundary portion between the tapered portion22and the straight portion23is enlarged to the same extent vertically. The material of the blind nut20is preferably steel.

(Range for the Length of the Tapered Portion22and the Straight Portion23) The relationship between the outer diameter D13and length l13of the tube-shaped portion (straight portion)13the blind nut10of the prior art inFIG. 1was used to determine the conditions enabling proper mounting of the blind nut.FIG. 13is a graph showing the range of the outer diameter D13of the straight portion13and the length l13of the straight portion13which enables proper mounting of the blind nut20. The length of the straight portion13is not the entire length l13of the straight portion13, but is the length of the straight portion13minus the panel thickness of the mounted member41(l13-t41). In other words, the length of the portion protruding from the mounted member41is related to the enlarged diameter.

The upper limit line inFIG. 13indicates the upper limit of the length of the portion of the straight portion13protruding from the mounted member41(l13-44l) relative to the outer diameter D13of the straight portion13. When the length of the straight portion13exceeds the upper limit, buckling problems tend to occur when the blind nut10is mounted. The lower limit line indicates the lower limit of the length l13of the straight portion13relative to the outer diameter D13of the straight portion13. When the length of the straight portion13is less than the lower limit, buckling problems tend to occur when the blind nut10is mounted.

When the length of the straight portion13is between the upper limit and the lower limit, the blind nut10can be mounted properly without causing buckling problems. The upper limit and the lower limit can be expressed using the following equations:
Upper Limit Equationy1=0.35x1+1.5  (Equation 1)
Lower Limit Equationy1=0.09x1+0.15  (Equation 2)

Here, the diameter of the straight portion13is D13=x1mm and the length of the straight portion13is l13=y1mm. The range of the length l13for the straight portion13that enables proper mounting of the blind nut10is expressed by the following equation.
0.09x1+0.15<y1<0.35x1+1.5  (Equation 3)

As inFIG. 13, the relationship between the outer diameter D23of the straight portion23(the outer diameter at the upper end of the tapered portion22), and the length122of the tapered portion22in the blind nut20of the present embodiment was used to determine the range enabling proper mounting of the blind nut20.FIG. 14is a graph showing the range of the outer diameter at the upper end of the tapered portion22(equal to the outer diameter D23of the straight portion23) and the length l22of the tapered portion22. The upper limit line inFIG. 14indicates the upper limit of the length l22of the tapered portion22relative to the outer diameter D23of the straight portion23. When the length of the tapered portion22exceeds the upper limit, buckling problems tend to occur when the blind nut20is mounted. The lower limit line indicates the lower limit of the length l22of the tapered portion22relative to the outer diameter D23of the straight portion23. When the length of the tapered portion22is below the lower limit, buckling problems tend to occur when the blind nut20is mounted.

When the length l22of the tapered portion22is between the upper limit and the lower limit, the blind nut20can be properly mounted without causing buckling problems. The upper limit and the lower limit can be expressed using the following equations:
Upper Limit Equationy2=0.45x2+1.4  (Equation 4)
Lower Limit Equationy2=0.22x2+0.4  (Equation 5)

Here, the diameter of the tapered portion22at the upper end is D23=x2mm, and the length l22of the tapered portion22is l22=y2mm. The range of the length l22for the tapered portion22that enables proper mounting of the blind nut20is expressed by the following equation.
0.22x2+0.4<y2<0.45x2+1.4  (Equation 6)

In a blind nut20of the present embodiment having a straight portion23and a tapered portion22, the length l23of the straight portion23is a constant value (satisfying Equation 3), and the length l22of the tapered portion22shown inFIG. 14is increased.

In order to determine the proper dimensional range for the length l22of the tapered portion22in the blind nut20of the present embodiment shown inFIG. 3, a mounting operation simulation was performed using the finite element method. The length of the straight portion23was constant (l23=11 mm). There were three types of blind nut20used in the simulation: one with a short tapered portion22(l22s=3.3 mm), one with a medium-length tapered portion22(l22m=5.0 mm), and one with a long tapered portion22(l22l=6.7 mm). In the simulation, the blind nuts were fastened to a thin mounted member (panel thickness: t41s=3.3 mm) and to a thick mounted member (panel thickness: t41l=5.5 mm).

FIG. 15throughFIG. 20show the results of simulations run under various conditions.FIG. 15is a simulation in which a thin panel (t41s) mounted member41is mounted using a blind nut20with a short tapered portion22(l22s).FIG. 15(a) throughFIG. 15(c) show the right half relative to the central axis y.FIG. 15(a) shows the stage in which the blind nut20is set in the mounted member41.FIG. 15(b) shows the intermediate mounting stage.FIG. 15(c) shows the final mounting stage of the blind nut20in which the tapered portion22and the straight portion23have been curved, an enlarged-diameter portion27has been formed, and the mounted member41has been interposed between the enlarged-diameter portion27and the flange24. InFIG. 15(c), the enlarged-diameter portion27occurs away from the bottom surface of the mounted member41, and buckling has occurred.

FIG. 16is a simulation in which a thick panel (t41l) mounted member41is mounted using a blind nut20with a short tapered portion22(l22s).

FIG. 17is a simulation in which a thin panel (t41s) mounted member41is mounted using a blind nut20with a medium-length tapered portion22(l22m).

FIG. 18is a simulation in which a thick panel (t41l) mounted member41is mounted using a blind nut20with a medium-length tapered portion22(l22m).

FIG. 19is a simulation in which a thin panel (t41s) mounted member41is mounted using a blind nut20with a long tapered portion22(l22l).

InFIG. 16throughFIG. 19, the large-diameter portion27comes into contact with the surface of the mounted member41, and the blind nut20is mounted properly.

FIG. 20is a simulation in which a thick panel (t41l) mounted member41is mounted using a blind nut20with a long tapered portion22(l22l). InFIG. 20(c), the enlarged-diameter portion27occurs away from the bottom surface of the mounted member41, and buckling has occurred.

The simulation results are summarized in Table 1.

The following is clear from the simulation results. A blind nut20with a straight portion23and a tapered portion22according to the present invention can be reliably fastened to a thick mounted member when the tapered portion22is short, but buckling is likely to occur when fastened to a thin mounted member. When the length of the tapered portion22is adjusted, it can be reliably fastened to a thick or thin mounted member. When the tapered portion22is long, the blind nut can be reliably fastened to a thin mounted member, but buckling is likely to occur when fastened to a thick mounted member.

In the embodiment of the present invention, the tube-shaped portion of the blind nut has a straight portion and a tapered portion. As a result, the blind nut can be easily mounted to mounted members such as panels having a wide range of thicknesses.

KEY TO TEXT IN FIGURES