Insulated blind rivet mounting and method of making

An insulated blind rivet mounting arrangement in an aperture in a wall including a blind rivet having a tubular rivet member and a actuating rod that is disposed within the tubular member and is adapted for axial withdrawal therefrom; an insulating sheath made of non-electrically conductive material positioned over said tubular rivet member; and said blind rivet actuating rod being removable from said tubular rivet member for expanding the tubular rivet member and insulating sheath into tight interfitting relation with each other within the wall aperture. Alternative embodiments are disclosed in which one or more coaxially disposed tubular flanged members are utilized to complete the mounting, with the insulating sheath being effective to thermally and electrically insulate the tubular rivet member. The insulating sheath, which preferably is made of a resilient plastic material, also is effective for creating a substantially vibration-free mounting within the wall aperture.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to blind rivet type fasteners, and 
more particularly, to improved mounting and connecting arrangements 
utilizing such type fasteners. 
2. Description of the Prior Art 
Fasteners known as blind rivets are used in numerous mounting and fastening 
applications. The blind rivet fastener typically comprises a metallic 
tubular rivet member having an outwardly extending mounting flange at one 
end and an actuating rod that extends axially through the tubular rivet 
member and has an enlarged end or head disposed adjacent the opposite or 
terminal end of the tubular rivet member. The tubular rivet member may be 
positionable, for example, through aligned apertures in a pair of plates 
to be secured together, with the flanged end thereof adjacent one side of 
the plates and the opposite or terminal end thereof extending through the 
other side of the plates. Upon axial withdrawal of the actuating rod, the 
enlarged head thereof causes the terminal end of the tubular rivet member 
to be expanded, such that the plates are retained between the expanded and 
flanged ends of the tubular rivet member. Withdrawal of the rod typically 
is effected by a manually or automatically operated tool, and the force of 
the withdrawal movement of the rod causes the enlarged head to break off 
so as to either be retained in the expanded end of the tubular rivet 
member or to fall free of the completed connection. 
Although blind rivet type fasteners have been advantageously used in 
numerous fastening and mounting applications, heretofore there are many 
applications for which they have been deemed unsuitable, or for which they 
have not been easily adaptable. For example, because the tubular rivet 
member is metallic, such fasteners have been unsuitable in electrical 
applications in which it is necessary that there be no electrical contact 
between the fastener and the wall or plates being secured. Likewise, 
because of the relatively high heat conductivity of the metallic tubular 
rivet member, blind rivet fasteners may be unsuitable in applications that 
cannot tolerate heat transfer through the fastener. In addition, it has 
been difficult to achieve connections in which the tubular rivet member is 
firmly retained in the mounting aperture without some relative movement or 
vibration, particularly when the fastener is secured in an aperture in 
relatively hard material, such as metal. For similar reasons, conventional 
blind rivets have not been suitable for applications where sound 
conductivity through the fastener must be minimized. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an insulated blind 
rivet mounting arrangement that is easily adaptable for applications 
heretofore considered unsuitable for blind fasteners. 
Another object is to provide a blind rivet mounting arrangement as 
characterized above that is adaptable for preventing electrical 
conductivity through the connection. 
A further object is to provide a blind rivet mounting arrangement of the 
foregoing type that includes a thermal insulating barrier for preventing 
heat transfer through the connection. 
Still another object is to provide a blind rivet mounting arrangement which 
is adapted for vibration-free securement in mounting apertures in even 
relatively hard materials, such as metal. 
Another object is to provide a blind rivet mounting arrangement which 
limits sound conductivity through the fastener. 
Still a further object is to provide a blind rivet mounting arrangement 
which is relatively simple in design and lends itself to economical 
manufacture and use. 
A further object is to provide a method of making of an insulated 
connection of the foregoing type.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
While the invention is susceptible of various modifications and alternative 
constructions, a certain illustrated embodiments thereof have been shown 
in the drawings and will be described below in detail. It should be 
understood, however, that there is no intention to limit the invention to 
the specific forms disclosed, but on the contrary, the intention is to 
cover all modifications, alternative constructions and equivalents falling 
within the spirit and scope of the invention. 
Referring now more particularly to FIG. 1 of the drawings, there is shown 
an illustrative mounting arrangement 10 in accordance with the invention, 
in this case being applied through an aperture 11 in a wall 12. The wall 
12 in this instance comprises a central insulating layer 14 having 
metallic or electrically conductive surfaces 15, 16 on opposed sides 
thereof. The mounting arrangement 10 includes a blind rivet 20, which as 
shown FIG. 2 comprises a metallic tubular rivet member 21 having an 
outwardly extending flange 22 at one end and an actuating rod 24 that 
extends axially through the tubular rivet member and has an enlarged 
rounded end or head 25 disposed adjacent the opposite or terminal end of 
the tubular rivet member 21. It will be understood that the blind rivet 20 
may be of a conventional type, such as the blind fastener sold under the 
trademark POP RIVET by Emhart Fastener Group, of Sheldon, Connecticut. As 
is known in the art, the actuating rod 24 of such blind rivet may be 
axially withdrawn from the tubular rivet member 21 by an appropriate tool, 
causing the enlarged head 25 to expand the terminal end of the tubular 
rivet member 21 and to break off the head 25 from the rod during the 
course of the withdrawal process. 
In accordance with the invention, means are provided for electrically and 
thermally insulating the metallic tubular rivet member within the wall 
mounting. To this end, in the illustrated embodiment, a tubular insulating 
sheath 30, which may be made of a resilient plastic material, is 
positioned over the tubular rivet member 21, as is shown in FIG. 3, 
preferably in relatively tight fitting relation, prior to the positioning 
of the blind rivet 20 into the mounting aperture 11. The blind rivet 20 
and insulating sheath 30 may thereupon be positioned into the aperture 11 
from one side of the wall 12 with the mounting flange 22 of the tubular 
rivet member 21 adjacent the side 15 of the wall. The tubular rivet member 
21 and insulating sheath 30 in this case are received in a second tubular 
member or eyelet 31, which like the tubular rivet member 21 may be made of 
metal and has an outwardly extending mounting flange 32 that is 
positionable adjacent an opposite side 16 of the wall 12. With the tubular 
rivet member 21 and insulating sheath 30 disposed within the second 
tubular member 31, the actuating rod 24 may be withdrawn from the tubular 
rivet member 21 by a manual or automated tool as is known in the art, for 
causing the enlarged head 25 thereof to be drawn into the tubular rivet 
member 21, causing expansion of the tubular rivet member 21 and sheath 30 
into tight interfitting relation with the second tubular member 31, with 
the tubular rivet member 21 and second tubular member 31 being positively 
retained within the mounting aperture 11 by the flanges 22, 32 and being 
insulated from each other by the sheath 30. As is known in the art, during 
the course of withdrawal of the rod 24, the enlarged head 25 may be 
severed from the rod and either drop from the formed connection or be 
retained in the completed connection. 
It will be appreciated that in the completed mounting arrangement 10 the 
flanged end 22 of the tubular rivet member 21 is in electrical contact 
with the metallic surface 15 on one side of the wall and the flanged end 
32 of the second tubular member 31 is in electrical contact with the 
metallic surface 16 on the opposite side of the wall 12, with the 
insulating sheath 30 insulating the rivet member 21 and second tubular 
member 31 from each other, and thus, maintaining an electrically insulated 
separation between the wall surfaces 15, 16. The insulating sheath 30 
further forms a thermal insulating barrier between the tubular rivet 
member 21 and second tubular member 31, and thus, between the opposite 
metallic surfaces 15, 16 of the wall 12. Because of the resiliency of the 
plastic sheath 30, the frictional bond between the tubular rivet member 21 
and second tubular member 31 is substantially vibration-free. While not 
essential to the mounting arrangement 10 illustrated in FIG. 1, axial 
withdrawal of the actuator rod 24, in addition to expanding the tubular 
rivet member 21 and insulating sheath 30, preferably also expands the 
second tubular member 31, at least slightly, so that it is in relatively 
tight fitting relation within the wall aperture 11. 
Referring now to FIG. 4, there is shown an insulated mounting arrangement 
10a substantially identical to that described above, formed by a modified 
method, wherein items similar to those described above have been given 
similar reference numerals with the distinguishing suffix "a" added. In 
this instance, as depicted in FIG. 5, the insulating sheath 30a is first 
positioned within the second tubular member 31a, preferably in relatively 
tight fitting relation, and this assembly is thereupon positioned into the 
mounting aperture 11a from one side of the wall 12, and the tubular rivet 
member 21a is then positioned into the insulating sheath 30a and second 
tubular member 31a from the opposite side of the wall. Withdrawal of the 
actuating rod 24a completes the connection, which is substantially similar 
to that shown in FIG. 1, in that the tubular rivet member 21a is firmly 
retained in thermally and electrically isolated relation within the second 
tubular rivet member 31a with the sheath disposed therebetween. 
Referring now to FIGS. 6-8, there is shown another alternative embodiment 
of mounting arrangement 10b, which is adapted for preventing passage of 
vapor and liquid through the mounting aperture. The mounting arrangement 
10b is substantially similar to that shown in FIG. 1 except the insulating 
sheath 30b has a closed end 35. The open end of the sheath 30b in this 
instance is positionable into tight-fitting relation over the tubular 
rivet member 20b, as shown in FIGS. 7 and 8, and this assembly is then 
positioned into the wall aperture 11b from one side thereof and is 
received in a second tubular member 31b that is positioned in the wall 
aperture from the other side thereof, as previously described. Withdrawal 
of the actuating rod 24b causes expansion of the tubular rivet member 21b 
and insulating sheath 30b into tight interfitting relation within the 
second tubular member 31b, again as previously described, with the closed 
end 35 of the sheath 30b creating a vapor seal through the aperture. It 
will be understood that alternatively the insulating sheath 30b could be 
positioned within the second tubular member 31b with the tubular rivet 
member 21b thereupon being positioned into the insulating sheath 30b and 
second tubular member 31b. 
Referring now to FIGS. 9 and 10 there shown a substantially vibration-free 
mounting arrangement 10c in which the tubular rivet member 21c is 
maintained in thermally and electrically isolated the relation to the wall 
12c, which again comprises a central layer 14c of insulating material with 
metallic or electrically conductive surfaces 15c, 16c on opposite sides 
thereof. An insulating sheath 30c having an outwardly extending flange 36 
is positionable over the tubular rivet member 21c with the flange 36 of 
the sheath 30c adjacent the flange 22c of the tubular rivet member. This 
assembly is then positioned into the wall aperture 11c with the insulating 
sheath flange 36 interposed between the metallic surface 15c of the wall 
12 and the tubular rivet member flange 22c and the opposite or terminal 
ends of the tubular rivet member 21c and sheath 30c extend outwardly 
beyond the opposite side 16c of the wall 12. Withdrawal of the actuating 
rod 24c expands the outwardly extending ends of the tubular rivet member 
21c and insulating sheath 30c into rigid, substantially vibration-free 
engagement with the wall aperture, with the mounting being positively 
retained within the aperture 11c between the flanges 36, 22c of the sheath 
30c and tubular rivet member 21, respectively and the outwardly expanded 
ends of the tubular rivet member 21c and insulating sheath 30c. 
Referring now to FIG. 11, there is shown a mounting arrangement 10d, 
substantially similar to that shown in FIG. 9, in which a metallic lead or 
mounting plate 38 is secured between the outwardly extending flange 22d of 
the tubular rivet member 21d and the outwardly extending flange 36d of the 
insulating sheath 30d so as to be in thermally and electrically isolated 
relation to the wall 12d. 
Referring now to FIG. 12, there is shown still another embodiment of a 
mounting arrangement 10e in accordance with the invention, in this case 
being mounted in a blind hole or aperture 11e that does not extend 
completely through the wall 12e. The tubular rivet member 21e with 
metallic mounting or lead plate 38e secured in interposed relation between 
the outwardly extending flange 22e of the tubular rivet member 21e and the 
outwardly extending flange 36e of the sheath 30e are positionable into the 
blind aperture 11e. Upon withdrawal of the actuating rod 24e of the blind 
rivet 20e the terminal or lowermost ends of the tubular rivet member 21e 
and insulating sheath 30e are expanded into tight, vibration-free, 
engagement with the interior walls of the aperture 11e with the sheath 30e 
electrically and thermally isolating the tubular rivet member 21e and 
metallic plate 38e from the wall 12e. 
Referring now to FIG. 13, there is shown a mounting arrangement 10f in a 
blind hole 11f substantially similar to FIG. 12, except that the sheath 
30f does not have an outwardly extending flange so that the metallic piece 
38f is secured in electrical conducting relation with the wall 12f. 
Referring now to FIG. 14, there is shown still another embodiment of 
mounting arrangement 10g in which a pair of flanged tubular members 31g, 
40 are utilized with an insulating sheath 30g interposed therebetween. The 
insulating sheath 30g may be placed within the flanged tubular member 31g, 
as shown in FIGS. 15 and 16, which is thereupon positioned in the wall 
aperture 11g with the flange 32g of the tubular member 31gdisposed 
adjacent one side 16g of the wall 12g and the tubular member 40 is 
positioned into the insulating sheath 30g with its outwardly extending 
flange 41 adjacent the opposite side 15g of the wall, as shown in FIG. 17. 
The tubular rivet member 21g is then positioned within the tubular member 
40, and upon withdrawal of the actuating rod 24g, causes the tubular rivet 
member 21g, tubular member 40, insulating sheath 30g, and tubular member 
31g, to be expanded into tight interfitting engagement with the aperture 
11g, with the mounting being positively retained within the wall aperture 
between the outwardly extending flange 32g of the tubular member 31g on 
one side and the outwardly extending flanges 22g, 41 of the tubular member 
21g and tubular rivet member 40, respectively, on the other side. The 
tubular rivet member 21g and tubular member 40 in this case are in 
electrically conductive relation with the metallic wall surface 15g and 
are thermally and electrically insulated from the tubular member 31g which 
is in contact with the metallic surface 16g on the opposite side of the 
wall. 
Referring now to FIG. 18, there is shown another embodiment of mounting 
arrangement 10h according to the invention wherein the mounting is 
positively retained within the wall aperture 11h between an outwardly 
extending flange 22h of the tubular rivet member 21h and an outwardly 
extending flange 36h of the insulating sheath 30h. The insulating sheath 
30h is positioned into the wall aperture 11h from one side 16h of the 
wall, with its outwardly extending flange 36h adjacent the wall surface. 
The tubular rivet member 21h is then positioned into the wall aperture 11h 
and insulating sheath 30h from the opposite side of the wall, and upon 
removal of the actuating rod 24h, expands the tubular rivet member 21h and 
insulating sheath 30h into securely mounted relation in the wall aperture, 
with the mounting being positively retained by the flanges 22h, 36h of the 
tubular rivet member and insulating sheath. 
From the foregoing, it can be seen that the present invention provides a 
multiplicity of blind rivet mountings which are adapted to electrically 
and thermally isolate the tubular rivet member from the wall and/or other 
elements of the connection. The mounting arrangements also are adapted for 
providing substantially vibration-free securement of the blind rivet 
member within the wall aperture and for minimizing sound conductivity 
through the connection. The mountings further are of relatively simple and 
economical construction and are easy to install.