CA1283527C - Fastening element, method of attachment and panel assembly - Google Patents
Fastening element, method of attachment and panel assemblyInfo
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- CA1283527C CA1283527C CA000521298A CA521298A CA1283527C CA 1283527 C CA1283527 C CA 1283527C CA 000521298 A CA000521298 A CA 000521298A CA 521298 A CA521298 A CA 521298A CA 1283527 C CA1283527 C CA 1283527C
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- panel
- barrel portion
- aperture
- annular
- barrel
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Abstract
FASTENING ELEMENT, METHOD OF ATTACHMENT
AND PANEL ASSEMBLY
152,35 ABSTRACT OF THE DISCLOSURE
A riveting or self-fastening element such as a stud for permanent attachment to a panel preferably having a preformed panel opening, including the method of attachment and the panel assembly. The self-attaching element includes an annular barrel portion having a conical external surface which is press fitted in the panel opening to deform the panel opening and form a mating conical internal surface preventing further penetration of the fastening element into the panel. The free end of the barrel portion, which is preferably cylindrical, is simultaneously deformed outwardly in a die member having an annular die cavity, forming an annular rim which is U or hook-shaped in cross section, wherein the free end is biased against the panel preventing pull-out of the fastening element. The fastening element, method of attachment and panel assembly is particularly adapted for relatively thick metal panels, including panels having a thickness greater than 0.1 inches.
AND PANEL ASSEMBLY
152,35 ABSTRACT OF THE DISCLOSURE
A riveting or self-fastening element such as a stud for permanent attachment to a panel preferably having a preformed panel opening, including the method of attachment and the panel assembly. The self-attaching element includes an annular barrel portion having a conical external surface which is press fitted in the panel opening to deform the panel opening and form a mating conical internal surface preventing further penetration of the fastening element into the panel. The free end of the barrel portion, which is preferably cylindrical, is simultaneously deformed outwardly in a die member having an annular die cavity, forming an annular rim which is U or hook-shaped in cross section, wherein the free end is biased against the panel preventing pull-out of the fastening element. The fastening element, method of attachment and panel assembly is particularly adapted for relatively thick metal panels, including panels having a thickness greater than 0.1 inches.
Description
12 !335~7 1~2.359 FASTENING ELEMENT, METHOD OF ATTACHMENT
AND PANEL ASSEMBLY
RELATED APPLICATIONS
This application is related to my co-pending U.S.
application Serial No. 773,387, filed September 6, 1985, now U.S. Patent 4,633,560 which application was a division of Serial No. 563,833, filed December 21, 1983, now United States patent No. 4,555,838. That patent is related to U.S. applications Serial Nos. 458,099, filed March 28, 1983, now United States Patent No. 4,459,073 and Serial No. 504,074, filed June 14, 1983, now United States Patent No. 4,543,701. Such cases were related to U.S. application Serial No. 229,274, filed January 28, 1981, now abandoned, which claimed priority from a published application filed February 2, 1980 in the Federal Republic of German~ No. 3 003 908.
FIELD OF THE INVENTION AND
SUMMARY OF THE PRIOR ART
The present inYention relates to an improved riveting or self-attaching element, such as a stud, bolt, nut or the like which is att~ched to a p~nel and which includes a riveting portion.
As disclosed more fully in my Above-referenced related U.S. applications and pfltents, the prior art discloses various means of attaching an eleT~nt to a panel. The f~stening elernent of this invention is particulQrly ad2pted for attachment to a rel~tively thick panel having a preformed or prepierced panel opening. Various methods and fastening elements have been disclosed -and described in the prior ~rt for att~chment to a pQnel or plate having a preformed opening, including United States Patent No. 1,953,197 which discloses a rnethod of ~ttsching ~ b~ll element of a ball pint to an engine cylinder, I~.S. Patent No.
3~432,925, which discloses various methods of securing a riYet contact, U.S.
~2835Z~
52.3 j9 Patent No. 3,556,189, which discloses methods of attaching studs in B blind hole and U.S. Paten~ No. 4,193,333, which discloses a clinch-type fastener and method of attaching a stud-type elernent to a relatively thick panel. Reference is also ~de to the prior art cited in my above-identified related U.S. applications ~nd patents.
The disclosures of my above-identified related U . S . applications patents were primarily concerned with fastening elements and methods of attaching such elements to a metal panel such as used by the automotive industry for body p~nels, structural elements and the like h~ving a thickness generally less than about 2.Smn or 0.098 inches. ln fact, Qn object of such fQstening elements was to permit attachment to relstively thin panels, including panels having ~ thickness of about û.031 inches, in a continuous operation, preferably including piercing the panel. The disclosed festening elements and methods of installation are still preferred in most automotive applications, however, the need remains for a fastening element suitable Eor installation in relatively thick or heavy guage metal panels, including panels having a thickness ranging from about 0.06 to 0.3 inches or greater.
The prior art methods of attachment and self-fastening elernents cited above are not suitable for rn~ny applications, particularly in relatively heavy guage panels used for automotive applications. Such automotive applications have minimurn st~ndards of push-through and pull-off, requiring joint integrity in both directions. Further, the fastener cost must be kept at a minimum and the rrethod of installation must be relatively simple, permitting automation of the installation process. Because of these difficulties, stud or bolt-type fasteners are norrnally attached to relatively thick panels in automotive applications by welding~ The method of attaching a weld stud or fastener generally does not pemlit very accurate location of the stud on the panelS welding methods require inspection of the weld joint, and weld methods on galvanized metals emit toxic vapors. Thus, welding methods ~re not suitable for meny automotive 1~2.35~ ~Z~Z7 applications, particularly where the fastener must be very accurately located on the panel or the connection cannot be easily inspected.
The need therefore remains for a fastening element and method of attaching a fastening element to a relatively heavy guage panel, including panels having a thickness greater than about 0.1 inches. The fastening element and method of this invention solves the problems associated with the prior art in a manner which permits automation of the installation method and the fastening element and method are suitable for automotive applications.
SUMMAR Y ~F THE INVENTION
The self-fastening or riveting element of this invention includes a body portion and an integral annular barrel portion having external and internal surfaces terminating in a free end. The external surface of the barrel portion includes a conical surface portion which is tapered outwardly from adjacent the free end. The barrel portion in the most preferred embodiment of the invention includes a cylindrical external surface adjacent the free end which guides the barrel portion into the panel opening or aperture and which is riveted or deformed in a die member to permanently attach the fastening element to the panel. In the preferred embodiment of the stud-type or male fastening element, the barrel portion is closed and a stud, bolt or other element extends integrally from the closed end of the barrel portion, preferably in coaxial alignment with the barrel portion.
As described, the method of attachment of this invention is particularly adapted for relatively thick panels, such as used by the automotive industry for structural elements, including 'brackets, frame elements and the like.
The fastening element and method of this invention is particularly adapted for securement in a panel having a thickness greater than about 0.1 inches and the fastening element has been successfully installed in panels having a thickness of 1~2.35~ ~2a3~iz7 0.31;) inches and greater. It will be understood, however, that the fastening elemen~ and metho~ of in~stallation of this invention may also be used for thinner panels having a thickness of about 0.06 inches, for example. It is believed, however, that the methods of installation and self-fastening elements disclosed in my above-identified related applications and patents will be more suitable for panel thicknesses less than about 0.1 inches.
l`he method of this invention includes forming a generally circular aperture through the panel having a cylindrical internal surface with a diameter generally about equal to the minor diameter of the conical surface on the barrel portion. That is, the diameter of the panel aperture should be generally equal to or slightly less than the minor diameter of the conical surface, which is the diameter of the cylindrical portion of the barrel in the preferred embodiment of the fastening element. The cylindrical external portion of the barrel guides the barrel portion into the panel aperture. The method next includes locating the fastening element barrel portion free end adjacent the panel with the annular barrel portion generally coaxially aligned with the panel aperture and a die member located on the opposite side of the panel. The die member includes an annular concave die cavity surrounding a central portion having an exterior diameter generally equal to the diameter of the internal barrel surface and coaxially aligned with the barrel portion.
The method next includes driving the barrel portion free end through the panel aperture, into the die cavity and the remaining steps are preferably performed in a continuous operation, nearly simultaneously. The conical surface of the barrel portion is driven against the cylindrical internal surface of the panel aperture, press fitting and reforming the internal surface of the panel aperture into a mating conical surface which resists further penetration of the barrel portion through the panel aperture. Sirnultaneously, the free end of the barrel portion is deformed radially outwardly in the die cavity and reversed against the panel, forrning a radially outwardly extending annular rim, which is ~2~3~27 52.359 hook-shaped in cross-section, wherein the free end of the barrel portion is biased against the panel, spaced radially outwardly from the panel aperture.
The hook-shaped end portion of the barrel thus prevents removal of the fastening element from the panel in the direction opposed to the direction of installation. The cone-shaped surfaces of the panel and barrel portion thus cooperate with the hook-shaped rim portion formed in the end of the barrel to prevent push-through or pull-out of the fastening element, which is thereby permanently attached to the panel.
In the most preferred method of this invention, the free cylindrical end portion of the barrel is entrapped in the die cavity and simultaneously thickened and deforrned radially outwardly, forming an enlarged hook-shaped portion which is resiliently biased against the panel, for~ning a very secure installation. Because of the thickness of the panel, it is generally not possible to draw the panel into the die opening or deform a substantial portion of the panel into the annular rim formed in the barrel portion. In the preferred method, however, a small circular rim may be Eormed in the panel, which extends into the annular barrel portion rim adjacent the minor diameter of the panel aperture and which provides a mechanical interlock between the panel and the barrel portion.
The preferred embodiment of the self-attaching element includes an annular driving surface which extends generally perpendicular to the axis of the annular barrel portion for driving the barrel portion into the preformed panel opening. The internal surface of the barrel portion rnay be generally cylindrical, threaded or unthreaded, proYiding a sirnple and inexpensive construction. As will be understood, the resultant panel assembly includes rn0ting press-fitted conical surfaces on the exterior of the barrel portion and the panel aperture which resist penetration of the barrel portion, and the barrel portion includes a U or hook-shaped annular rim having a free end portion which is preferably resiliently biased against the panel spaced from the panel aperture.
3~;27 15~.3~
In the disclosed embodiment, the barrel portion retained in the panel aperture is generally disk-shaped having an annular shoulder which is flush-mounted in the panel and which closes the end of the barrel portion. The fastening element may also include a body portion which extends from the plane of the disk-shaped portion. The body portion may include or comprise a secondary fastening element, such as a stud, bolt, ball element or the like. Alternatively, the barrel portion may comprise a secondary fastening element, such as a nut fastener.
Other advantages and meritorious features of the fastening element, method of attacl~nent and panel assembly of this invention will be more fully understood from the following description of the preferred ernbodiments, appended claims and the drawings, a brief description of which follows.
BRIEF DESCRIPTION OF T~E DRAWINGS
Figure 1 is a partially cross sectioned side view of a self-attaching stud being installed in a panel and elements of the installation apparatus including a die member and plunger;
Figure 2 illustrates the continuing sequence of installation of the stud ; member shown in Figure l;
Figure 3 illustrates the panel assembly formed by the stud mernber and method of installation of Figures 1 and 2;
'~
Figure 4 is a partially cross sectioned side view of an embodiment of the self-attaching element of this invention, suitable for installation in relatively thick panels, and elements of the installation apparatus;
Figure 5 is similar to Figure 4 except that the self-fastening element has been partially insta~led in the panel;
3~9 ~2~33~27 Figure 6 is a side partia~y cross-sectioned vie~ of the ~ssennbly shown in Figures 4 and 5 fo~owing insta~ation of the self-fastening ele ~ nt; and Figure 7 is an enlarged partial view of Figure 6.
DESC RlPrIO~ OF T HE PREFER RED EM BO DIMENTS A N D METH O D
The fo~owing detailed description of the preferred embodinnænts and thod references copending United States patent application Serial No.
773,387, filed Septennber 6, 1985 and United States Patent No. 4,555,838, which issued fr ~ the parent Qpplication of the copending application. Figures 1 to 3 of this applicstion are t~ken from the above-referenced copending application and patent and disclosç the preferred ennbod~nænts of the self-piercing and riveting nn~le-type fastener and nnethod of insta~ing the fastener in ~ "thin"
panel. As described, this method is sti~ preferred in p~nels h~ving Q thickness up to about 0.1 inches because the nnethod does not require ~ preforned or prepierced panel ~perture and the ~ thod nnay be perfo m ed in a single continuous operation~ including piercing. Reference is also made to my copending applicati.on Serial No. 657,570, filed October 4, 1984, now U.S. Patent 4,610,072 which was related to U.S. application Serial No. 563,833, now U.S. Patent No. 4,555,838. The '072 patent discloses alternative methods of installing ~emale-type fasteners in a continuous operation.
Figures 1 to 3 illustrate the preferred insta~ation sequence and nnethod of insta~ing the stud-type fastener 20 in a relatively thin psnel 22 as disclosed in the above-identified copending epplication serifll No. 773,387, f~ed Septen~ber 6, 1985 ~nd the p~rent application which issued ~s United States Patent No. 495551838. The disclosed stud-type fastener includes a head portion 24 in the fo~n of a radial flange, an unthreaded shank portion 26 ~nd a self-piercing and riveting annul~r barrel portion 28. The outer or exterior surface 30 of the annular barrel portion in the disclosed ~nnbodLm~nt is generally .
, . , , . . ~
., .
' ~2~5~
~2.359 cylindric~l and terrninates in a rounded driving and drawing surface at the radial~y outer surface of the free end 32 of the barrel portion. The barrel portion includes a central recess or opening 34 which is defined by the cylindrical internal surface 36 and the bottom wall 38. The inner surface 36 of the barrel portion terminates in an annular piercing surface 40 ~djacent the free end 32 of the barrel portion. The bottom wall 38 in the disclosed ernbodiment isconical and concave, as shown in Figure 3.
The top surface 44 of the head portion 24 includes an annular driving surface adjacent the shank 26 and the bottom surface 46 of the head defines an annular bearing surface. It will be understood that "top" and "bottorn" are relative terms depending upon the orientation of the fastener and are used herein only for descriptive purposes. The fastener of this invention may be attached with a die member or button located either on the top or the bottom shoe of a die press, for example. Further, the annular barrel portion 28 may be OI any annular configuration, including cylindrical, as shown, hexagonal, octagonal, etc. The disclosed embodiment, however, is relatively sirnple and provides excellent retention, as described below.
The installation method disclosed in Figures 1 to 3, begins with orienting the stud fastener 20 relative to the panel 22 and the die mernber 50.
The die member includes a panel supporting or seating shoulder 52 which surrounds an annular die cavity 54. The annular die cavity 54 surrounds a central die portion 56 which includes a convex conical surface 58, preferably including a rel~tively sharp apex 60 ~nd the conical surface surrounds an annular surfQce 62. The ~nnul~ die cavity 54 includes an inclined or sloped outer surface 64 which blends into a panel supporting shoulder or lip 66 through a ~ oth ercuate surface. The bottorn surface 68 of the annular die cavity is semi-toroidal and tenninates in the annular shoulder or p~nel supporting lip 66.
~2~33~27 152.35 As shown in Figure 1, the panel 22 is first deformed into the annular die cavity 5~. The panel is first engaged by the free end 32 of the annular barrel portion. The panel portion located inside the annular wall is then domed or trepanned against the conical surface 58 of the free end of the central projecting die portion 56/ fixing this portion of the panel prior to piercing or shearing, as now described.
The panel is then pierced or sheared as shown in Figure 2. The panel is sheared between the piercing surface 40 of the annular barrel portion and the piercing edge 70 located at the outer edge of the proiecting central die portion 56, forming a panel slug 75 which is disposed within the fastener barrel portion recess 34 on the conical free end 58 of the projecting die portion. It will be understood that the configuration of the die member piercing ~dge 70 should be the same as the configuration of the annular wall 28, such that the mating piercing surfaces pierce the panel. The piercing surface 40 of the barrel portion is preferably a chamfer face inclined outwardly from the axis of the annular barrel portion. The she~ring of the panel then occurs along the shearing face 40, forming a panel slug 75 having an external diameler slightly greater than the internal diameter of the inner surface 36 of the annular wall, providing an interference fit. The inclined piercing face 40 is "self-correcting" and assures a clean shearing of the panel with a minimum of force.
Figure 3 illustrates the final configuration of the stud-type fastener 20 and the panel assembly. The annular barrel portion 28 now includes a first tubular portion 80 ~nd a second radially outwardly hook-shaped end portion 82, however, the barrel portion has generally the same thickness as the original configuration. The slug 75, which was pierced from the main portion of the panel 22, has been deformed against the bottom wall surface 38 of the barrel portion recess by the conical free end 58 of the central projecting die portion 56. The panel slug becomes an integral part of the fastener and panel assembly. The panel 22 now includes a rnain portion 22 bearing against the _g_ 152.359 1;~35~7 panel supporting shoulder 52 of the die button, a second portion 84 drawn and displaced form the plane of the main panel portion and ccnforming to the inclined outer wa~ 64 of the die cavity and the annular lip 66J which has limited the defor~tion of the panel into the die cavity and which supported the panel during the final deformation of the panel in the hook-shaped end portion 82 of the barrel portion. During the final insta~ation, the panel portion surrounding the pierced panel edge is driven into the developing hook-shaped channel 82 of the barrel portion, thickening the panel portion as shown at 86. As disclosed more fu~y in the above-identified copending application, the insta~ation apparatus includes an insta~ation head (not shown) which receives the stud fasteners and which includes a reciprocal plunger 90 having a bore 92 which receives the shank portion 26 of the fastener and an annular driving surface 94 which bears against the annular driving surface 44 of the fastener and which drives the barrel portion 28 of the fastener into the panel, as described above.
H~ving described one embodiment of a self-piercing and riveting stud-type fastener and the method of insta~ation, it wi~ be understood that there is a practical limit to the thickness of the panel 22 to which the self-piercing and riveting f~stener 20 may be attached. First, the barrel portion 28 must pierce the panel 22, limiting the thickness of the panel. Further, the panel is drawn into the die opening, as shown in Figures 1 and 2, and the panel is then driven into the developing hook-shaped end portion 82, fo~ning a thickened end portion ~6, which is entrapped within the hook-shaped barrel portion. ~f course, the thickness of the panel to which the fastener ~ y be attached will also be dependent upon the size and thickness of the barrel portion. The size of the barrel portion is, however, dete~nined in practical application by the size of the bolt. Thus, an alternative design and method of insta~ation is necessary to acconl~odate relatively thick panels for conventional bolt sizes, as described ~bove.
~igures 4 to 7 i~ustrate an alternative ennbodiment of the self-.
~L2~33527 52.35' fastening element of this invention particularly adapted for attachrnent to a relatively thick panel or a panel having a substantial thickness, i.e., gr~ater than about 0.1 inches and including thicknesses greater than 0.3 inches. An M8 stud (stud having a thread crest diameter of 8~n) of the type disclosed, for example, is suitable for attachment to a panel having a thickness of 6mn and an Ml2 stud can accommodate an 8mn panel. Again, the illustrated self-fastening element is a stud-type fastener having a body portion 102 in the fo~n of a male threaded bolt, and an annular barrel portion 104. The barrel portion in the disclosed ernbodiment includes a generally cylindrical internal surface 106 and an external surface including a cylindrical end surface portion 108 and a conical surface portion 110. The barrel portion includes a free end 112, which in the disclosed and preferred embodiment is a convex arcuate surface which joins the internal and external surfaces of the barrel portion. The barrel portion definesan internal cavity 11~ which is enclosed by bottom wall 116. In the disclosed embodiment, the bottom wall 116 also defines a disk-shaped body portion having a conical outer surface 110 and a top driving surface 118.
~ s described above, the panel 120 may be relatively thick and the panel preferably includes a preformed or prepierced cylindrical aperture 122.
As shown, the diameter of the aperture 122 is generally egual to the minor diarneter of the cone-shaped surface 110, which is the diameter of the cylindrical surface 108. The cylindrical annular end portion of the barrel portion guides the barrel portion into the cylindrical panel aperture 122, as shown in Figure 4. As will be understood, the barrel portion 104 is aligned with the panel aperture, and a die member 124 is located on the opposite side of the panel. The die member includes an annular concave die cavity 126 having an internal surface 128 which closely receives the internal surface 106 of the barrel portion. The concave die cavity is serni-toroidal, but the die cavity does not include a panel receiving lip, as described above in regard to Figures 1 to 3, because the panel is not deformed into the die cavity. The die member does include a central die portion 130, which in the disclosed err~odiment includes a ~IL283~27 ~.359 conic~l end portion 132.
As disclosed more fully in the above-identified copending U.S. application and ll.S. Patent No. 4,555,838, the install~tion ~pp~rstus includes R plunger 134 having an annul~r surf~ce 136 which drives the fastener into the panel. The disclosed embodirnent also includes a gage pin 138 which indicates the presence - of a fastening element in the bore 140 of the plunger, ready for installation.
As described in the copending ~pplication, the fastening elements are serially received in the installation head ~nd located in the plunger ready fo instflllation.
Figures 4 to 7 illustrate tbe method of installation and Installation sequence of this invention. Pirst, BS described, the barrel portion 104 of the fsstening element is located adjacent the panel with the barrel portion coaxially aligned with the panel aperture and the die mernber, as shown in Figure 4. The free end 112 of the barrel portion 104 is then driven through the panel aperture 122 into the die cavity 126 by the plunger 134 as shown in Figure 5. The conical extern~l surface 110 of the barrel portion is press fitted into the cylindrical aperture 122 in the panel, deforming the internal cylindrical surface of the aperture apd forrning a mating conical surface. The free end 112 of the barrel portion is simultaneously deformed radially outwardly against the semi-toroidal concave die cavity surface 126. As best shown in Figure 6, the cylindrical end portion of the barrel portion is deformed in the annular die cavity to substantially fill the annulHr die cavity and entrapped therein to form a thickened annular channel 140 which is hook-shaped in cross section and wherein the free end 112 of the barrel por~ion is resilien~ly biased ugainst the bottom surface 142 of the p~nel, spaced radially from the panel sperture 122.
As shown in Figures 6 and 7, the cylindrical surf~ce of the panel aperture h~s been deformed into a conical surface 122~, which fuUy mates with the conic~l surface 110 of the barrel portion, limi~ing further penetration of the barrel portion into the panel opening. Further, the annular driving surface 118 is ., ~Z83~27 152.359 driven flush with the top surface 144 of the panel, such that the threaded bolt portion 102 extends from the plane of the panel 144.
As best shown in Figure 7, the edge of the panel 120 adjacent the panel opening 122a is deforrned slightly to improve the retention of the fastening element to the panel. A small circular lip 146 is formed into the annular channel or hook-shaped portion 140, providing a rrechanical interlock between the barrel portion and the panel. The mating conical surfaces 110 and 122a thus prevent "push-through" of the fastening element through the panel opening in the direction of the installation of the fasterling element. The enlarged hook-shaped annular channel 140, including the free end 112 which is resiliently biased against the bottom face 142 of the panel, prevents 'lpull-out"
in the opposite direction. The panel assembly is therefore quite secure, particularly in a panel of substantial thickness, as described above.
As will be understood, the configuration of the fastening element 100 may be modified as reguired by the application. Thus, the male threaded shank 102 may be replaced with an Imthreaded shank, a ball member for a ball and socket joint, a hinge member or removed entirely to form a female element, such as a nut fastener, in which case the internal surface 106 may be internally threaded. Other modifications may be made to the fastening element, method of installation and panel assembly of this invention within the purview of the appended claims.
~`~
.
~ -13-
AND PANEL ASSEMBLY
RELATED APPLICATIONS
This application is related to my co-pending U.S.
application Serial No. 773,387, filed September 6, 1985, now U.S. Patent 4,633,560 which application was a division of Serial No. 563,833, filed December 21, 1983, now United States patent No. 4,555,838. That patent is related to U.S. applications Serial Nos. 458,099, filed March 28, 1983, now United States Patent No. 4,459,073 and Serial No. 504,074, filed June 14, 1983, now United States Patent No. 4,543,701. Such cases were related to U.S. application Serial No. 229,274, filed January 28, 1981, now abandoned, which claimed priority from a published application filed February 2, 1980 in the Federal Republic of German~ No. 3 003 908.
FIELD OF THE INVENTION AND
SUMMARY OF THE PRIOR ART
The present inYention relates to an improved riveting or self-attaching element, such as a stud, bolt, nut or the like which is att~ched to a p~nel and which includes a riveting portion.
As disclosed more fully in my Above-referenced related U.S. applications and pfltents, the prior art discloses various means of attaching an eleT~nt to a panel. The f~stening elernent of this invention is particulQrly ad2pted for attachment to a rel~tively thick panel having a preformed or prepierced panel opening. Various methods and fastening elements have been disclosed -and described in the prior ~rt for att~chment to a pQnel or plate having a preformed opening, including United States Patent No. 1,953,197 which discloses a rnethod of ~ttsching ~ b~ll element of a ball pint to an engine cylinder, I~.S. Patent No.
3~432,925, which discloses various methods of securing a riYet contact, U.S.
~2835Z~
52.3 j9 Patent No. 3,556,189, which discloses methods of attaching studs in B blind hole and U.S. Paten~ No. 4,193,333, which discloses a clinch-type fastener and method of attaching a stud-type elernent to a relatively thick panel. Reference is also ~de to the prior art cited in my above-identified related U.S. applications ~nd patents.
The disclosures of my above-identified related U . S . applications patents were primarily concerned with fastening elements and methods of attaching such elements to a metal panel such as used by the automotive industry for body p~nels, structural elements and the like h~ving a thickness generally less than about 2.Smn or 0.098 inches. ln fact, Qn object of such fQstening elements was to permit attachment to relstively thin panels, including panels having ~ thickness of about û.031 inches, in a continuous operation, preferably including piercing the panel. The disclosed festening elements and methods of installation are still preferred in most automotive applications, however, the need remains for a fastening element suitable Eor installation in relatively thick or heavy guage metal panels, including panels having a thickness ranging from about 0.06 to 0.3 inches or greater.
The prior art methods of attachment and self-fastening elernents cited above are not suitable for rn~ny applications, particularly in relatively heavy guage panels used for automotive applications. Such automotive applications have minimurn st~ndards of push-through and pull-off, requiring joint integrity in both directions. Further, the fastener cost must be kept at a minimum and the rrethod of installation must be relatively simple, permitting automation of the installation process. Because of these difficulties, stud or bolt-type fasteners are norrnally attached to relatively thick panels in automotive applications by welding~ The method of attaching a weld stud or fastener generally does not pemlit very accurate location of the stud on the panelS welding methods require inspection of the weld joint, and weld methods on galvanized metals emit toxic vapors. Thus, welding methods ~re not suitable for meny automotive 1~2.35~ ~Z~Z7 applications, particularly where the fastener must be very accurately located on the panel or the connection cannot be easily inspected.
The need therefore remains for a fastening element and method of attaching a fastening element to a relatively heavy guage panel, including panels having a thickness greater than about 0.1 inches. The fastening element and method of this invention solves the problems associated with the prior art in a manner which permits automation of the installation method and the fastening element and method are suitable for automotive applications.
SUMMAR Y ~F THE INVENTION
The self-fastening or riveting element of this invention includes a body portion and an integral annular barrel portion having external and internal surfaces terminating in a free end. The external surface of the barrel portion includes a conical surface portion which is tapered outwardly from adjacent the free end. The barrel portion in the most preferred embodiment of the invention includes a cylindrical external surface adjacent the free end which guides the barrel portion into the panel opening or aperture and which is riveted or deformed in a die member to permanently attach the fastening element to the panel. In the preferred embodiment of the stud-type or male fastening element, the barrel portion is closed and a stud, bolt or other element extends integrally from the closed end of the barrel portion, preferably in coaxial alignment with the barrel portion.
As described, the method of attachment of this invention is particularly adapted for relatively thick panels, such as used by the automotive industry for structural elements, including 'brackets, frame elements and the like.
The fastening element and method of this invention is particularly adapted for securement in a panel having a thickness greater than about 0.1 inches and the fastening element has been successfully installed in panels having a thickness of 1~2.35~ ~2a3~iz7 0.31;) inches and greater. It will be understood, however, that the fastening elemen~ and metho~ of in~stallation of this invention may also be used for thinner panels having a thickness of about 0.06 inches, for example. It is believed, however, that the methods of installation and self-fastening elements disclosed in my above-identified related applications and patents will be more suitable for panel thicknesses less than about 0.1 inches.
l`he method of this invention includes forming a generally circular aperture through the panel having a cylindrical internal surface with a diameter generally about equal to the minor diameter of the conical surface on the barrel portion. That is, the diameter of the panel aperture should be generally equal to or slightly less than the minor diameter of the conical surface, which is the diameter of the cylindrical portion of the barrel in the preferred embodiment of the fastening element. The cylindrical external portion of the barrel guides the barrel portion into the panel aperture. The method next includes locating the fastening element barrel portion free end adjacent the panel with the annular barrel portion generally coaxially aligned with the panel aperture and a die member located on the opposite side of the panel. The die member includes an annular concave die cavity surrounding a central portion having an exterior diameter generally equal to the diameter of the internal barrel surface and coaxially aligned with the barrel portion.
The method next includes driving the barrel portion free end through the panel aperture, into the die cavity and the remaining steps are preferably performed in a continuous operation, nearly simultaneously. The conical surface of the barrel portion is driven against the cylindrical internal surface of the panel aperture, press fitting and reforming the internal surface of the panel aperture into a mating conical surface which resists further penetration of the barrel portion through the panel aperture. Sirnultaneously, the free end of the barrel portion is deformed radially outwardly in the die cavity and reversed against the panel, forrning a radially outwardly extending annular rim, which is ~2~3~27 52.359 hook-shaped in cross-section, wherein the free end of the barrel portion is biased against the panel, spaced radially outwardly from the panel aperture.
The hook-shaped end portion of the barrel thus prevents removal of the fastening element from the panel in the direction opposed to the direction of installation. The cone-shaped surfaces of the panel and barrel portion thus cooperate with the hook-shaped rim portion formed in the end of the barrel to prevent push-through or pull-out of the fastening element, which is thereby permanently attached to the panel.
In the most preferred method of this invention, the free cylindrical end portion of the barrel is entrapped in the die cavity and simultaneously thickened and deforrned radially outwardly, forming an enlarged hook-shaped portion which is resiliently biased against the panel, for~ning a very secure installation. Because of the thickness of the panel, it is generally not possible to draw the panel into the die opening or deform a substantial portion of the panel into the annular rim formed in the barrel portion. In the preferred method, however, a small circular rim may be Eormed in the panel, which extends into the annular barrel portion rim adjacent the minor diameter of the panel aperture and which provides a mechanical interlock between the panel and the barrel portion.
The preferred embodiment of the self-attaching element includes an annular driving surface which extends generally perpendicular to the axis of the annular barrel portion for driving the barrel portion into the preformed panel opening. The internal surface of the barrel portion rnay be generally cylindrical, threaded or unthreaded, proYiding a sirnple and inexpensive construction. As will be understood, the resultant panel assembly includes rn0ting press-fitted conical surfaces on the exterior of the barrel portion and the panel aperture which resist penetration of the barrel portion, and the barrel portion includes a U or hook-shaped annular rim having a free end portion which is preferably resiliently biased against the panel spaced from the panel aperture.
3~;27 15~.3~
In the disclosed embodiment, the barrel portion retained in the panel aperture is generally disk-shaped having an annular shoulder which is flush-mounted in the panel and which closes the end of the barrel portion. The fastening element may also include a body portion which extends from the plane of the disk-shaped portion. The body portion may include or comprise a secondary fastening element, such as a stud, bolt, ball element or the like. Alternatively, the barrel portion may comprise a secondary fastening element, such as a nut fastener.
Other advantages and meritorious features of the fastening element, method of attacl~nent and panel assembly of this invention will be more fully understood from the following description of the preferred ernbodiments, appended claims and the drawings, a brief description of which follows.
BRIEF DESCRIPTION OF T~E DRAWINGS
Figure 1 is a partially cross sectioned side view of a self-attaching stud being installed in a panel and elements of the installation apparatus including a die member and plunger;
Figure 2 illustrates the continuing sequence of installation of the stud ; member shown in Figure l;
Figure 3 illustrates the panel assembly formed by the stud mernber and method of installation of Figures 1 and 2;
'~
Figure 4 is a partially cross sectioned side view of an embodiment of the self-attaching element of this invention, suitable for installation in relatively thick panels, and elements of the installation apparatus;
Figure 5 is similar to Figure 4 except that the self-fastening element has been partially insta~led in the panel;
3~9 ~2~33~27 Figure 6 is a side partia~y cross-sectioned vie~ of the ~ssennbly shown in Figures 4 and 5 fo~owing insta~ation of the self-fastening ele ~ nt; and Figure 7 is an enlarged partial view of Figure 6.
DESC RlPrIO~ OF T HE PREFER RED EM BO DIMENTS A N D METH O D
The fo~owing detailed description of the preferred embodinnænts and thod references copending United States patent application Serial No.
773,387, filed Septennber 6, 1985 and United States Patent No. 4,555,838, which issued fr ~ the parent Qpplication of the copending application. Figures 1 to 3 of this applicstion are t~ken from the above-referenced copending application and patent and disclosç the preferred ennbod~nænts of the self-piercing and riveting nn~le-type fastener and nnethod of insta~ing the fastener in ~ "thin"
panel. As described, this method is sti~ preferred in p~nels h~ving Q thickness up to about 0.1 inches because the nnethod does not require ~ preforned or prepierced panel ~perture and the ~ thod nnay be perfo m ed in a single continuous operation~ including piercing. Reference is also made to my copending applicati.on Serial No. 657,570, filed October 4, 1984, now U.S. Patent 4,610,072 which was related to U.S. application Serial No. 563,833, now U.S. Patent No. 4,555,838. The '072 patent discloses alternative methods of installing ~emale-type fasteners in a continuous operation.
Figures 1 to 3 illustrate the preferred insta~ation sequence and nnethod of insta~ing the stud-type fastener 20 in a relatively thin psnel 22 as disclosed in the above-identified copending epplication serifll No. 773,387, f~ed Septen~ber 6, 1985 ~nd the p~rent application which issued ~s United States Patent No. 495551838. The disclosed stud-type fastener includes a head portion 24 in the fo~n of a radial flange, an unthreaded shank portion 26 ~nd a self-piercing and riveting annul~r barrel portion 28. The outer or exterior surface 30 of the annular barrel portion in the disclosed ~nnbodLm~nt is generally .
, . , , . . ~
., .
' ~2~5~
~2.359 cylindric~l and terrninates in a rounded driving and drawing surface at the radial~y outer surface of the free end 32 of the barrel portion. The barrel portion includes a central recess or opening 34 which is defined by the cylindrical internal surface 36 and the bottom wall 38. The inner surface 36 of the barrel portion terminates in an annular piercing surface 40 ~djacent the free end 32 of the barrel portion. The bottom wall 38 in the disclosed ernbodiment isconical and concave, as shown in Figure 3.
The top surface 44 of the head portion 24 includes an annular driving surface adjacent the shank 26 and the bottom surface 46 of the head defines an annular bearing surface. It will be understood that "top" and "bottorn" are relative terms depending upon the orientation of the fastener and are used herein only for descriptive purposes. The fastener of this invention may be attached with a die member or button located either on the top or the bottom shoe of a die press, for example. Further, the annular barrel portion 28 may be OI any annular configuration, including cylindrical, as shown, hexagonal, octagonal, etc. The disclosed embodiment, however, is relatively sirnple and provides excellent retention, as described below.
The installation method disclosed in Figures 1 to 3, begins with orienting the stud fastener 20 relative to the panel 22 and the die mernber 50.
The die member includes a panel supporting or seating shoulder 52 which surrounds an annular die cavity 54. The annular die cavity 54 surrounds a central die portion 56 which includes a convex conical surface 58, preferably including a rel~tively sharp apex 60 ~nd the conical surface surrounds an annular surfQce 62. The ~nnul~ die cavity 54 includes an inclined or sloped outer surface 64 which blends into a panel supporting shoulder or lip 66 through a ~ oth ercuate surface. The bottorn surface 68 of the annular die cavity is semi-toroidal and tenninates in the annular shoulder or p~nel supporting lip 66.
~2~33~27 152.35 As shown in Figure 1, the panel 22 is first deformed into the annular die cavity 5~. The panel is first engaged by the free end 32 of the annular barrel portion. The panel portion located inside the annular wall is then domed or trepanned against the conical surface 58 of the free end of the central projecting die portion 56/ fixing this portion of the panel prior to piercing or shearing, as now described.
The panel is then pierced or sheared as shown in Figure 2. The panel is sheared between the piercing surface 40 of the annular barrel portion and the piercing edge 70 located at the outer edge of the proiecting central die portion 56, forming a panel slug 75 which is disposed within the fastener barrel portion recess 34 on the conical free end 58 of the projecting die portion. It will be understood that the configuration of the die member piercing ~dge 70 should be the same as the configuration of the annular wall 28, such that the mating piercing surfaces pierce the panel. The piercing surface 40 of the barrel portion is preferably a chamfer face inclined outwardly from the axis of the annular barrel portion. The she~ring of the panel then occurs along the shearing face 40, forming a panel slug 75 having an external diameler slightly greater than the internal diameter of the inner surface 36 of the annular wall, providing an interference fit. The inclined piercing face 40 is "self-correcting" and assures a clean shearing of the panel with a minimum of force.
Figure 3 illustrates the final configuration of the stud-type fastener 20 and the panel assembly. The annular barrel portion 28 now includes a first tubular portion 80 ~nd a second radially outwardly hook-shaped end portion 82, however, the barrel portion has generally the same thickness as the original configuration. The slug 75, which was pierced from the main portion of the panel 22, has been deformed against the bottom wall surface 38 of the barrel portion recess by the conical free end 58 of the central projecting die portion 56. The panel slug becomes an integral part of the fastener and panel assembly. The panel 22 now includes a rnain portion 22 bearing against the _g_ 152.359 1;~35~7 panel supporting shoulder 52 of the die button, a second portion 84 drawn and displaced form the plane of the main panel portion and ccnforming to the inclined outer wa~ 64 of the die cavity and the annular lip 66J which has limited the defor~tion of the panel into the die cavity and which supported the panel during the final deformation of the panel in the hook-shaped end portion 82 of the barrel portion. During the final insta~ation, the panel portion surrounding the pierced panel edge is driven into the developing hook-shaped channel 82 of the barrel portion, thickening the panel portion as shown at 86. As disclosed more fu~y in the above-identified copending application, the insta~ation apparatus includes an insta~ation head (not shown) which receives the stud fasteners and which includes a reciprocal plunger 90 having a bore 92 which receives the shank portion 26 of the fastener and an annular driving surface 94 which bears against the annular driving surface 44 of the fastener and which drives the barrel portion 28 of the fastener into the panel, as described above.
H~ving described one embodiment of a self-piercing and riveting stud-type fastener and the method of insta~ation, it wi~ be understood that there is a practical limit to the thickness of the panel 22 to which the self-piercing and riveting f~stener 20 may be attached. First, the barrel portion 28 must pierce the panel 22, limiting the thickness of the panel. Further, the panel is drawn into the die opening, as shown in Figures 1 and 2, and the panel is then driven into the developing hook-shaped end portion 82, fo~ning a thickened end portion ~6, which is entrapped within the hook-shaped barrel portion. ~f course, the thickness of the panel to which the fastener ~ y be attached will also be dependent upon the size and thickness of the barrel portion. The size of the barrel portion is, however, dete~nined in practical application by the size of the bolt. Thus, an alternative design and method of insta~ation is necessary to acconl~odate relatively thick panels for conventional bolt sizes, as described ~bove.
~igures 4 to 7 i~ustrate an alternative ennbodiment of the self-.
~L2~33527 52.35' fastening element of this invention particularly adapted for attachrnent to a relatively thick panel or a panel having a substantial thickness, i.e., gr~ater than about 0.1 inches and including thicknesses greater than 0.3 inches. An M8 stud (stud having a thread crest diameter of 8~n) of the type disclosed, for example, is suitable for attachment to a panel having a thickness of 6mn and an Ml2 stud can accommodate an 8mn panel. Again, the illustrated self-fastening element is a stud-type fastener having a body portion 102 in the fo~n of a male threaded bolt, and an annular barrel portion 104. The barrel portion in the disclosed ernbodiment includes a generally cylindrical internal surface 106 and an external surface including a cylindrical end surface portion 108 and a conical surface portion 110. The barrel portion includes a free end 112, which in the disclosed and preferred embodiment is a convex arcuate surface which joins the internal and external surfaces of the barrel portion. The barrel portion definesan internal cavity 11~ which is enclosed by bottom wall 116. In the disclosed embodiment, the bottom wall 116 also defines a disk-shaped body portion having a conical outer surface 110 and a top driving surface 118.
~ s described above, the panel 120 may be relatively thick and the panel preferably includes a preformed or prepierced cylindrical aperture 122.
As shown, the diameter of the aperture 122 is generally egual to the minor diarneter of the cone-shaped surface 110, which is the diameter of the cylindrical surface 108. The cylindrical annular end portion of the barrel portion guides the barrel portion into the cylindrical panel aperture 122, as shown in Figure 4. As will be understood, the barrel portion 104 is aligned with the panel aperture, and a die member 124 is located on the opposite side of the panel. The die member includes an annular concave die cavity 126 having an internal surface 128 which closely receives the internal surface 106 of the barrel portion. The concave die cavity is serni-toroidal, but the die cavity does not include a panel receiving lip, as described above in regard to Figures 1 to 3, because the panel is not deformed into the die cavity. The die member does include a central die portion 130, which in the disclosed err~odiment includes a ~IL283~27 ~.359 conic~l end portion 132.
As disclosed more fully in the above-identified copending U.S. application and ll.S. Patent No. 4,555,838, the install~tion ~pp~rstus includes R plunger 134 having an annul~r surf~ce 136 which drives the fastener into the panel. The disclosed embodirnent also includes a gage pin 138 which indicates the presence - of a fastening element in the bore 140 of the plunger, ready for installation.
As described in the copending ~pplication, the fastening elements are serially received in the installation head ~nd located in the plunger ready fo instflllation.
Figures 4 to 7 illustrate tbe method of installation and Installation sequence of this invention. Pirst, BS described, the barrel portion 104 of the fsstening element is located adjacent the panel with the barrel portion coaxially aligned with the panel aperture and the die mernber, as shown in Figure 4. The free end 112 of the barrel portion 104 is then driven through the panel aperture 122 into the die cavity 126 by the plunger 134 as shown in Figure 5. The conical extern~l surface 110 of the barrel portion is press fitted into the cylindrical aperture 122 in the panel, deforming the internal cylindrical surface of the aperture apd forrning a mating conical surface. The free end 112 of the barrel portion is simultaneously deformed radially outwardly against the semi-toroidal concave die cavity surface 126. As best shown in Figure 6, the cylindrical end portion of the barrel portion is deformed in the annular die cavity to substantially fill the annulHr die cavity and entrapped therein to form a thickened annular channel 140 which is hook-shaped in cross section and wherein the free end 112 of the barrel por~ion is resilien~ly biased ugainst the bottom surface 142 of the p~nel, spaced radially from the panel sperture 122.
As shown in Figures 6 and 7, the cylindrical surf~ce of the panel aperture h~s been deformed into a conical surface 122~, which fuUy mates with the conic~l surface 110 of the barrel portion, limi~ing further penetration of the barrel portion into the panel opening. Further, the annular driving surface 118 is ., ~Z83~27 152.359 driven flush with the top surface 144 of the panel, such that the threaded bolt portion 102 extends from the plane of the panel 144.
As best shown in Figure 7, the edge of the panel 120 adjacent the panel opening 122a is deforrned slightly to improve the retention of the fastening element to the panel. A small circular lip 146 is formed into the annular channel or hook-shaped portion 140, providing a rrechanical interlock between the barrel portion and the panel. The mating conical surfaces 110 and 122a thus prevent "push-through" of the fastening element through the panel opening in the direction of the installation of the fasterling element. The enlarged hook-shaped annular channel 140, including the free end 112 which is resiliently biased against the bottom face 142 of the panel, prevents 'lpull-out"
in the opposite direction. The panel assembly is therefore quite secure, particularly in a panel of substantial thickness, as described above.
As will be understood, the configuration of the fastening element 100 may be modified as reguired by the application. Thus, the male threaded shank 102 may be replaced with an Imthreaded shank, a ball member for a ball and socket joint, a hinge member or removed entirely to form a female element, such as a nut fastener, in which case the internal surface 106 may be internally threaded. Other modifications may be made to the fastening element, method of installation and panel assembly of this invention within the purview of the appended claims.
~`~
.
~ -13-
Claims (21)
1. A method of permanently attaching a metal element to a plastically deformable panel having a predetermined substantial thick-ness, said element having a driving surface and an annular barrel portion, said barrel portion including external and internal surfaces terminating in a free end, said barrel port ion external surface including a conical surface portion tapered outwardly from adjacent said free end, said method comprising the following steps:
(a) forming a generally circular aperture through said panel having a generally cylindrical internal surface having a diameter generally equal to the minor diameter of said exterior conical surface of said barrel portion;
(b) locating said element barrel portion free end adjacent said panel with said annular barrel portion generally coaxially aligned with said panel aperture and a die member located on the opposite side of said panel, said die member having a concave generally annular die cavity including an inner surface generally conforming to and coaxially aligned with said internal barrel surface, and a panel supporting surface adjacent said die cavity to support said panel;
(c) driving said barrel portion free end through said panel aperture, into said die cavity, and performing the following steps in a continuous operation;
(d) driving said barrel portion conical external surface against said panel aperture generally cylindrical internal surface, plastically deforming said panel aperture internal surface to generally conform to said conical barrel surface, said conical surfaces resisting further penetration of said barrel portion through said panel aperture; and (e) plastically deforming said barrel portion free end radially outwardly in said die cavity, forming a radially outwardly extending hook-shaped end portion, with said barrel portion free end engaging said panel, said hook-shaped end portion resisting pull-out of said barrel portion from said panel aperture.
(a) forming a generally circular aperture through said panel having a generally cylindrical internal surface having a diameter generally equal to the minor diameter of said exterior conical surface of said barrel portion;
(b) locating said element barrel portion free end adjacent said panel with said annular barrel portion generally coaxially aligned with said panel aperture and a die member located on the opposite side of said panel, said die member having a concave generally annular die cavity including an inner surface generally conforming to and coaxially aligned with said internal barrel surface, and a panel supporting surface adjacent said die cavity to support said panel;
(c) driving said barrel portion free end through said panel aperture, into said die cavity, and performing the following steps in a continuous operation;
(d) driving said barrel portion conical external surface against said panel aperture generally cylindrical internal surface, plastically deforming said panel aperture internal surface to generally conform to said conical barrel surface, said conical surfaces resisting further penetration of said barrel portion through said panel aperture; and (e) plastically deforming said barrel portion free end radially outwardly in said die cavity, forming a radially outwardly extending hook-shaped end portion, with said barrel portion free end engaging said panel, said hook-shaped end portion resisting pull-out of said barrel portion from said panel aperture.
2. The method of attaching an element to a panel defined in claim 1, including simultaneously thickening and plastically deforming said barrel portion free end, forming said enlarged hook-shaped end portion, engaging said 152.359 panel spaced radially from said panel aperture.
3. The method of permanently attaching an element to a panel as defined in claim 1, wherein said barrel portion conical external surface is spaced from said free end by a generally cylindrical external surface having a diameter generally equal to said panel aperture, said barrel portion external surface guiding said barrel portion into said panel aperture, and said method including deforming said cylindrical portion radially outwardly, forming said radially outwardly extending hook-shaped end portion.
4. The method of permanently attaching an element to a panel as defined in claim 3, wherein said method includes simultaneously thickening and deforming said cylindrical barrel end portion radially outwardly, forming an enlarged hook-shaped end portion engaging said panel, spaced radially from said panel aperture.
5. The method of permanently attaching an element to a panel as defined in claim 1, wherein said panel is supported on a surface surrounding said die cavity during installation of said element, said panel being generally planar adjacent said aperture and remaining generally planar during said installation.
6. The method of permanently attaching an element to a panel as defined in claim 5, wherein said method includes deforming a small circular panel portion at the periphery of said aperture extending into said hook-shaped barrel end portion, mechanically interlocking said panel portion and said barrel portion.
7. A method of permanently attaching a metal element to a panel, said panel having a predetermined substantial thickness and a generally circular aperture through said panel having a generally cylindrical internal surface, said element having a driving surface and an annular barrel portion, said barrel portion including internal and external surfaces terminating in a free end, said barrel portion external surface including a conical surface portion tapered outwardly from adjacent said free end having a minor diameter generally equal to the internal diameter of said panel aperture, said method comprising the following steps performed in a generally continuous sequence:
(a) locating said element barrel portion free end adjacent said panel with said annular barrel portion generally coaxially aligned with said panel aperture and a die member located on the opposite side of said panel, said die member including a concave annular die cavity and a panel supporting surface on at least opposed sides of said die cavity supporting said panel;
(b) driving said barrel portion free end through said panel aperture, into said die cavity, said barrel portion conical external surface plastically deforming said panel aperture cylindrical surface to generally conform to and mate with said conical barrel surface, said mating conical surfaces resisting further penetration of said barrel portion through said panel aperture; and (c) plastically deforming said barrel portion free end radially outwardly in said die cavity, entrapping and thickening said barrel portion and turning said barrel portion free end to engage said panel spaced from said aperture, forming an enlarged annular rim end portion on said barrel portion being hook-shaped in cross section and preventing pull-out of said element from said panel aperture.
(a) locating said element barrel portion free end adjacent said panel with said annular barrel portion generally coaxially aligned with said panel aperture and a die member located on the opposite side of said panel, said die member including a concave annular die cavity and a panel supporting surface on at least opposed sides of said die cavity supporting said panel;
(b) driving said barrel portion free end through said panel aperture, into said die cavity, said barrel portion conical external surface plastically deforming said panel aperture cylindrical surface to generally conform to and mate with said conical barrel surface, said mating conical surfaces resisting further penetration of said barrel portion through said panel aperture; and (c) plastically deforming said barrel portion free end radially outwardly in said die cavity, entrapping and thickening said barrel portion and turning said barrel portion free end to engage said panel spaced from said aperture, forming an enlarged annular rim end portion on said barrel portion being hook-shaped in cross section and preventing pull-out of said element from said panel aperture.
8. The method of permanently attaching an element to a panel as defined in claim 7, wherein said barrel portion conical external surface is spaced from said barrel portion free end by a generally cylindrical external surface having a diameter generally equal to said panel aperture, said barrel portion external cylindrical surface guiding said barrel portion into said panel aperture and said method including deforming said cylindrical portion radially outwardly forming said enlarged annular rim.
152.359
152.359
9. The method of permanently attaching an element to a panel as defined in claim 7, wherein said panel is generally planar adjacent said aperture prior to installation and said method includes deforming a small circular panel portion at the periphery of said aperture extending into said barrel portion annular rim opening forming a mechanical interlock between said barrel portion and said panel.
10. A self-attaching element for permanent attachment to a panel in a preformed panel opening, said element including an annular barrel portion having internal and external surfaces extending to a free end, said free end having a generally smooth convex end surface joining said external and internal surfaces, said internal barrel surface being generally cylindrical, said external surface including a generally cylindrical surface adjacent said free end and a conical surface tapering outwardly from said cylindrical surface, and said self-attaching element including an annular driving surface generally perpen-dicular to the axis of said annular barrel portion for driving said barrel portion into a preformed panel opening.
11. The self-attaching element defined in claim 10, charac-terized in that said barrel portion internal cylindrical surface terminates in an end wall, closing said barrel portion and said self-attaching element includes a fastening element generally coaxially aligned with said barrel portion and integrally joined to said barrel portion at said end wall.
12. The self-attaching element defined in claim 11, characterized in that said fastening element is an externally threaded male stud.
13. A self-attaching element for permanent attachment to a panel in a preformed panel opening, said element including a body portion and an integral annular barrel portion, said annular barrel portion having internal and 52.359 external surfaces and a free end, said internal barrel surface being generally cylindrical and terminating in an end wall closing said barrel portion with said body portion integrally joined to said barrel portion at said end wall, said barrel portion external surface including a generally cylindrical surface extending from adjacent said free end and a conical surface tapered outwardly from said cylindrical surface surrounding said end wall and said element including a radially extending driving surface extending generally transverse to the axis of said annular barrel portion for driving said barrel portion into a preformed panel opening.
14. The self-attaching element defined in claim 13, character-ized in that said conical barrel surface terminates in an annular shoulder surrounding said body portion generally perpendicular to the axis of said annular barrel portion and defining said annular driving surface.
15. The self-attaching element defined in claim 13, charac-terized in that the internal surface of said end wall is concave.
16. A panel assembly, comprising: a panel and a fastening element, said panel including an aperture having a cone-shaped internal surface and said fastening element permanently attached to said panel within said panel aperture, said fastening element including a disk-shaped portion having a conical exterior surface generally conforming to and mating with said panel aperture conical internal surface, said mating cone-shaped surfaces limiting movement of said element in one direction, said fastening element having an annular rim extending integrally from adjacent the minor diameter of said disk-shaped portion, said rim being hook-shaped in cross section and having an annular end portion engaging said panel spaced radially outwardly from said panel aperture preventing pull-out of said element from said panel opening in the opposite direction, and said fastening element including a body portion extending from said disk-shaped portion opposite said rim.
152.359
152.359
17. The panel assembly as defined in claim 16, characterized in that said fastening element rim annular end portion is smooth, convex and resiliently biased against said panel portion.
18. The panel assembly as defined in claim 17, characterized in that said panel is generally planar adjacent said panel aperture except for a circular annular panel portion adjacent the periphery of said aperture which extends into said rim portion providing a mechenical interlock between said panel and said rim portion.
19. The panel assembly as defined in claim 16, characterized in that said disk-shaped portion is generally flush with the surface of said panel opposite said rim and said fastening element includes a fastening body portion extending from said panel surface.
20. A panel assembly comprising a panel and a fastening element, said panel including an aperture having a cone-shaped internal surface and said fastening element permanently attached to said panel within said panel aperture, said fastening element including a barrel portion having a cone-shaped external surface press fitted into said cone-shaped internal surface of said panel aperture, said mating cone-shaped surfaces preventing rnovement of said element in one direction, said barrel portion including an integral annular rim portion generally hook-shaped in cross-section including an annular free end engaging said panel spaced radially outwardly from said panel aperture adjacent the minor diameter of said conical surfaces, said annular rim free end being relatively smooth convex and resiliently biased against said panel preventing pull-out of said fastening element from said panel aperture in the opposite direction.
21. The panel assembly defined in claim 20, characterized in that said panel includes a circular panel portion at the periphery of said panel perture minor diameter which extends into said hook-shaped rim portion and , _ _ 152.35?
providing a mechanical interlock between said rim portion and said panel, said panel being otherwise generally planar adjacent said panel aperture.
providing a mechanical interlock between said rim portion and said panel, said panel being otherwise generally planar adjacent said panel aperture.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/852,689 US4713872A (en) | 1980-02-02 | 1986-04-16 | Method of attaching fastening element to a panel |
| US852,689 | 1992-03-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1283527C true CA1283527C (en) | 1991-04-30 |
Family
ID=25313977
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000521298A Expired - Lifetime CA1283527C (en) | 1986-04-16 | 1986-10-24 | Fastening element, method of attachment and panel assembly |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1283527C (en) |
-
1986
- 1986-10-24 CA CA000521298A patent/CA1283527C/en not_active Expired - Lifetime
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