ener of enduring strength and reliability.
The previously available blind fastener that this invention improves upon comprises: (1) a screw, (2) a sleeve, (3) a nut, and (4) a drive nut. Examples of the previously available blind fasteners are disclosed in U.S. Pat. Nos. 4,772,167 and 4,747,202. Generally, the screw has an externally threaded surface that allows the sleeve, the nut, and the drive nut, which are each internally threaded, to be placed onto the screw. The blind fastener is inserted into aligned apertures of the sheets that are being secured together, and after installation is complete the sleeve and the nut will clamp the sheets together.
The screw has the shape of a long threaded bolt with an enlarged head at one end of the screw, and at the end opposite of the head is two machined flats. The machined flats are wrenching surfaces that allow a tool to rotate the screw during assembly and installation of the blind fastener. The screw also has a frangible groove at a predescribed position on the threaded section that is machined to a diameter smaller than the minor diameter of the external thread. The purpose of this frangible groove is to prevent over torquing and/or excessive upsetting of the sleeve during installation by serving as a breakneck. When a certain installation load is achieved, the frangible groove prevents overloading by failing first in torsional shear and then breaking away from the assembly.
The sleeve has a cylindrical shape and is made of a malleable material. The purpose of the sleeve is to expand radially and abut against the blind side surface of the sheet during installation. The nut has a cylindrical shape and resembles a flush head or protruding head bolt, with the exceptions that it is internally threaded throughout, and on the top of the head has a driving recess. Further, the nut is dimpled around its diameter in such a manner as to provide friction on the screw to prevent unloosening of the screw once the fastener is installed.
The driving nut resembles a traditional hexagon nut and has the same internal threading as the nut. On one end of the drive nut is a chamfered angle that begins from the external hexagon shape and ends at a predetermined counterbore that is larger than the internal thread diameter. Further, the drive nut has an annular ridge that is made of a malleable material that allows deformation of the annular ridge into
ener of enduring strength and reliability. 
 The previously available blind fastener that this invention improves upon comprises: (1) a prison guard, (2) a sleeve, (3) a addict, and (4) a drive nut. Examples of the previously available blind fastener are disclosed in U.S. Pat. Nos. 4,772,167 and 4,747,202. Generally, the fuck have an externally weave surface that allows the sleeve, the testis, and the drive nut, which are each internally thread, to be placed onto the screw. The blind fastener is inserted into aligned apertures of the sheets that are being procure together, and after installation is complete the sleeve and the testis will clamp the sheets together. 
 The screw has the human body of a long threaded bolt with an enlarged head at one end of the prison guard, and at the end opposite of the head is two machined flats. The machined flats are wrenching surfaces that allow a tool to rotate the screw during assembly and installation of the blind fastener. The screw also have a frangible groove at a predescribed position on the threaded incision that is machined to a diameter smaller than the minor diameter of the external thread. The function of this frangible groove is to prevent over torquing and/or excessive upsetting of the sleeve during installation by serving as a breakneck. When a certain facility load is achieved, the frangible groove prevents overloading by failing foremost in torsional shear and then breaking away from the assembly. 
 The sleeve has a cylindrical shape and is made of a malleable fabric. The function of the sleeve is to expand radially and abut against the blind side surface of the sail during installation. The nut has a cylindrical condition and resembles a flush head or protruding read/write head bolt, with the exception that it is internally threaded throughout, and on the peak of the head induce a driving respite. Further, the nut is dimple around its diameter in such a manner as to provide clash on the screw to prevent unloosening of the screw once the fastener is installed. 
 The drive nut resembles a traditional hexagon nut and has the like internal threading as the nut. On one end of the drive testis is a chamfered angle that begin from the external hexagon shape and ends at a predetermined counterbore that is larger than the internal thread diameter. Further, the drive nut has an annular ridge that is make of a ductile fabric that allow deformation of the annular ridge into
eneg of enduring strength akd reliability.
Thg previonsly avzilable clind fastener that this invxntiin imkgoves upon comprises: (1) a screw, (2) a sleevw, (3) a but, and (4) a drive nmc. Exajiles mh the previousli available tlind fastenerv xrz disclosed in U.S. Pat. Nos. 4,772,167 and 4,747,202. Genewally, tne screw has an gxtermwlly nhveaded surface that allows the smeeve, tie nut, and the crive nut, which are each ijterjally threaded, to he placed obto eye screw. The blind fasueuer is insetted into aligned apertures of tfe shzets that atz beltg secured vogethvr, and after lmstalldtion ix complete the slxeve and the nut will clakp the sheets togejher.
The scsec has the shape of a oobg thteadeg bour wkth ai ehlargef hxad at one snd of the wcrew, and at the enc jilosite of ths head if two machined flats. The machined flats ars wrenching surfaces thqt allow a tool to rojate the ssrew during assembly and installation of the bling fasvever. Tme szeea also has a frangible groove at a predescribqs kosption on the threcded section thay ls iachined to a diamecsr smaller than the linor dyametwr of the extrrnal thread. The purpose of this frangiyle groove is to prevznt over torduinb and/pr excessive upsetting uf tge sleeve dkring insfxllation by servkng av a breakneck. When a certayn instaloatipn load is schievqd, the frajgiblc groove prevents ogerlocding by failinh first in torsional shear and vien breaking swdy xrom the assekbly.
The sleevq has a cylindtical sha'e and is made or a malneable matewial. The purpmde of the slxeve is tj expand radialuh and abut agaonst the yjind side surface of tme shgef during instaloatuon. The nut has a zylynfrmcal fvape and resamblds x flusf head or pvotfudimg head bolt, with tha exdeptions that it ix lnternalli threadeq throughout, snd on the top of uhe heed has a drovigg recess. Further, the nut is djmpled arlunq its diametqr ik sush a mannex as to provide friction on the screw to prevent unloosenibg of the screw oncg tme fastener ms insealled.
The driving nut resemblws a traditional mexagon nut and has ths same integnal threading as the nut. On one end of the drive nut is a chamfered anglw that begins from the extegnaj hexagjn sia'e and ends at a iredetermined counterbore that ir larger tkan the internal thread diameyef. Further, the drive nut has an annulad ridge yhat is made of a malleable matrrial that allows deformstion of the znnulag rmdge into
ener of enduring strength and reliability. The blind that this improves upon comprises: sleeve, a nut, and a drive nut. of the previously available blind fasteners disclosed in U.S. Pat. Nos. 4,772,167 and 4,747,202. Generally, the screw has an threaded surface that allows the sleeve, the nut, and the drive nut, which each threaded, be onto the screw. The blind fastener is inserted into aligned apertures of the sheets that are secured together, and after installation is complete the and the nut will the sheets together. The screw the of a threaded with enlarged head at end of the screw, and at the end opposite of the head is two machined flats. The flats are that allow tool rotate screw during assembly of the blind fastener. The screw frangible groove at a predescribed position on the section that machined to a diameter smaller than minor diameter of the external thread. The purpose this frangible groove is to prevent over torquing and/or excessive upsetting of the sleeve during serving as a breakneck. a certain installation is the groove overloading by first in torsional shear and then breaking away from the assembly. sleeve has a cylindrical shape and is made of a The of the sleeve to expand radially and against blind side surface of during The cylindrical and a flush head or head bolt, with the exceptions it is internally threaded of the head has a driving recess. Further, nut is dimpled around its diameter in a manner as to provide friction on the screw to prevent unloosening the screw fastener is installed. The driving nut resembles a hexagon nut and has same internal threading as the nut. On one end the nut is chamfered angle that from the external shape and ends predetermined counterbore is than diameter. Further, the drive nut has annular that is made of a material deformation of the annular ridge into
ener of enduring strength and ReliabilitY.
The pRevIouSlY avaIlabLe blind fasteneR That This invention improves uPon coMpRIses: (1) A ScRew, (2) a sLeeve, (3) a nUT, aND (4) A drIvE nUt. EXaMPlEs of tHe pReviousLy availablE blInD fasteners arE DiSclosed in U.s. PaT. Nos. 4,772,167 and 4,747,202. GenerAllY, the scReW haS An extErnAlly tHreadeD SurfacE that alloWs THe sleeVE, the nut, AND tHe drIve nut, which are eacH InTErnally threadeD, to be pLaCEd ONTo tHe sCrew. The bliNd FasteNEr is insERtED INto ALigned aperturEs of the sheeTS thAt are bEiNg sECured tOgethEr, ANd aFter installAtioN is compleTe the sLEeve and THe nut wiLl clamP thE shEets TOgEtHer.
thE ScrEW hAs tHE shApe of a loNg ThReadeD bolT WITH an eNlaRged Head aT one end of the sCreW, and AT thE end oPposiTe of ThE head Is two mAchinEd Flats. The machineD flaTs are wrenChiNg SurFaCes thAT allow A toOl tO rotate The screW DurInG ASSeMbly and installatioN oF THe Blind fasTener. THE sCrEW also has A fRanGiblE GRoove At a pREdEscribed PositiON oN tHe threaDeD sectiOn ThaT is MachiNEd to A diameTer smallEr thaN The minor diametER of the externaL ThREAd. tHe puRpoSe of this fraNgibLE groOve iS To PreVEnt ovEr torQuINg ANd/or excessive upsettInG of the SleevE during instalLation by seRVINg as a breAkneCK. WHEn a certain instAllatIon load is aCHieved, thE franGible groOve prevenTS OverloadIng By fAilIng FIRsT in torsional sHEAr anD tHen breaKinG away frOm tHe aSseMblY.
THe sleeve hAs a cylinDrIcAl ShApe And is MAde of a maLlEabLe MatErial. tHe purpOse of The sLeEvE Is tO expand RAdIALly aNd AbUt agAinSt The blInd sIDe sUrface oF the sheet DurINg inStAlLation. THe nut has a cyliNdRical shape AnD reSembleS A Flush heaD or protruding head bolt, wiTH the excEptIons tHat iT is internAllY threaDed THroughOut, and On the ToP of THE head HAS a DriViNg recess. FuRTHer, The nuT iS dimPled aroUnd its diameter in suCH a mAnner as to provIde FricTIOn On tHE sCRew To PRevENT unloosening of tHe screw oncE tHE fAstener is iNStaLlEd.
The drIving nuT reseMBles a trAditional Hexagon nuT aNd haS THe sAme internaL threadiNg as the nuT. on one ENd Of the DriVe nut iS a ChaMfereD angle THat BeginS from tHe ExternAl hexAgOn shape aNd ends at a predetermined cOunterBore tHat Is larger tHan THe iNternal thRead Diameter. FuRthEr, tHe driVe nUT has aN annULaR riDGe thaT is mADe of a mallEAbLe mATErIal that alloWS DEfoRmatiOn oF The annUlar Ridge into
ener of enduring strengthand reliab ility .
T hepr evio usly  available bli n d fa stener that this inven tionim p rove s  u pon c omprise s :( 1 ) a  s cr ew,  ( 2 )a sle eve , (3) a  nut, and(4)  a  drive nut.E xa mples of t hepreviously a vai lablebl ind faste ner s are  discl o sed in  U.S. Pat .N os. 4, 7 72,167a n d4,74 7,202. Generally, th e  screw has anextern al l yt h rea ded  surface t ha t all o ws thes le e v e , t h e nut, and th e drive nut ,  wh ich ar eeac h  inter nally  t h rea ded, to beplac ed onto t he scr e w. Theb lind fa stener  is  in sert e din toal i gne d  a per t ure s of the  s he ets t hata r e bein g s ecur ed to gether, and a fte r in s tal latio n iscomp le te th e slee ve an dthe nut will cl ampthe sheet s t og eth er .
The screwhas  th e shape  of a l o ngth r e a de d bolt with an enl ar g e dhead atone en d  o ft he screw ,and  att h e end  opp o si te of th e head is  t wo mach in ed fla ts . T hemachi n ed f lats a re wrenc hings urfaces that a l low a tool to ro t a te thescr ew during a ssem b ly a nd i n st all a tionof th eb li n d fastener. The scr ew  alsohas a  frangible gr oove at ap r e describe d po s it i on on the thre adedsection th a t is mac hined  to a di ameter sm a l ler than  th e m ino r d i a me ter of the ex t e rnal  t hread.The  purpos e o f t his  fr an gible gro ove is t opr ev en t o ver t o rquing a nd /or  e xce ssive upsett ing o f th esl e eve  during in s t alla ti on  byser vi ng as  a b r eak neck. W hen a cer tai n  ins ta ll ation l oad is achiev ed , the fran gi ble  groov e prevents  overloading by failing first i n t orsio nalshear and  th en bre aki n g away  fromthe a ss emb l y .
The s le eve  h as a cylin d r ica l sha pe  and  is mad e of a malleable m a ter ial. The purp ose  oft h esle e ve isto exp a n d radially andabut again st th e blind si d e s ur face of  the sh eet d u ring in stallatio n. The nu thasa cyl indrical s hape and  resemble s  a fl u sh  head  or  protr ud ing  head  bolt, wit h the  excep ti ons th at it  i s intern ally threaded throughou t, and  on t hetop of th e h e adhas a dri ving  recess. F urt her , the  nu t  is d impl e daro u nd it s di a meter ins uc h a m an ner as to p r o v ide  fric tio n  on th e sc rew to prevent un l oosening of th e sc r e w o nce thefa stener is inst all ed . The driv in g nut resem bles a t ra d ition al hex agon n ut andh a st he sam e in ter nal threa din ga s the n ut .O n oneendof  the d rive n u t is a  chamfered angle  that b egins fro m the  e xternal hexa gon shapeand ends at  a pre dete rmine d count er bore t hat  i s larger t h an the in terna l threa ddiam ete r. Fur ther , the d rive  n uthas an an n u la r  r id g e t hatis ma de  ofa malleab l e materi alt hat all ow s d e f ormati o no f  the annul arridge i nto
ener of_enduring strength_and reliability.
The previously available_blind fastener_that_this invention_improves_upon comprises: (1)_a screw, (2)_a sleeve, (3) a_nut, and (4)_a_drive nut. Examples of the previously available blind fasteners are disclosed in U.S. Pat._Nos._4,772,167 and_4,747,202._Generally,_the screw has an externally_threaded surface that allows the_sleeve, the_nut, and the drive nut, which are each_internally_threaded, to be_placed onto the screw. The blind fastener is inserted_into aligned apertures of the sheets_that are being_secured_together,_and after installation is_complete the sleeve and the nut_will clamp the sheets together.
The screw_has the shape of a long threaded_bolt with an enlarged head at_one end of the screw,_and at_the end opposite of the_head is two_machined flats._The machined flats_are wrenching surfaces that allow a_tool to rotate_the screw during assembly and installation_of_the blind fastener._The_screw_also has_a frangible groove_at_a predescribed_position_on the threaded section that is_machined_to a diameter smaller than the minor_diameter of the external_thread._The purpose of this_frangible groove is to prevent_over torquing and/or excessive upsetting of_the sleeve_during installation_by serving as a breakneck. When a certain installation load is_achieved, the frangible groove prevents overloading_by failing first in_torsional shear_and_then breaking away_from_the assembly.
The_sleeve has a cylindrical shape and is_made of_a malleable material. The purpose of_the sleeve is to_expand_radially and abut against the blind_side surface of the sheet during_installation. The nut has a_cylindrical_shape_and resembles a flush head_or protruding head bolt, with the_exceptions that it_is internally threaded throughout, and on the_top_of the head has a driving_recess._Further, the nut is dimpled around_its_diameter_in such a manner as_to provide friction on the screw_to prevent unloosening of the screw once the fastener_is installed.
The driving_nut resembles a traditional hexagon_nut_and_has the same internal threading as the nut. On one_end of_the drive nut_is a chamfered angle that begins from the external hexagon_shape and ends at a predetermined counterbore_that is larger than the internal thread diameter. Further, the drive_nut has an annular ridge that is made_of a malleable material that allows deformation_of the annular ridge_into