초록 ▼

A blind fastener has an assembly including an inner sleeve, an outer sleeve and a pin member and is adapted to be located in workpiece openings with the pin member having an expansion portion adapted to be pulled through the inner sleeve radially expanding both the inner and outer sleeves to provide

A blind fastener has an assembly including an inner sleeve, an outer sleeve and a pin member and is adapted to be located in workpiece openings with the pin member having an expansion portion adapted to be pulled through the inner sleeve radially expanding both the inner and outer sleeves to provide an interference fit with the workpiece openings.

대표청구항 ▼

[ What is claimed is:] [1.] A fastening system including a fastener for securing a plurality of workpieces together with the workpieces having aligned openings and with the workpieces having a forward surface and a rearward surface, said fastener comprising:an outer sleeve member having an elongated

[ What is claimed is:] [1.] A fastening system including a fastener for securing a plurality of workpieces together with the workpieces having aligned openings and with the workpieces having a forward surface and a rearward surface, said fastener comprising:an outer sleeve member having an elongated first sleeve shank terminating at a forward end in a first enlarged sleeve head and having a first bore extending axially therethrough,an inner sleeve member having an elongated second sleeve shank terminating at a rearward end in a second enlarged sleeve head and having a second bore extending axially therethrough,said inner sleeve member being assembled to said outer sleeve member with said second sleeve shank located in said first bore with a close tolerance fit with said second enlarged sleeve head being in confrontation with a rearward end of said first sleeve shank,a pin member having an elongated pin shank,said pin shank having a pull section at its forward end and an enlarged diameter expansion portion at its rearward end,said pin member having a large diameter ring portion located at the juncture of said pull section and said expansion portion,said pin member assembled to said inner and outer sleeve members with said ring portion adapted to be located in a counterbore in said second enlarged head portion and fixedly connected in said counterbore to said inner sleeve member,said pull section being of a length to extend axially outwardly from said first sleeve head and adapted to be gripped by an installation tool whereby a relative axial pulling force can be applied between said pin member and said outer sleeve member,said fastener adapted to be assembled to the workpieces with said first sleeve shank extending through said aligned openings with a predetermined generally clearance relationship,said fastener as assembled to the workpieces having said first sleeve head in engagement with said forward surface of the workpieces and with said rearward end of said outer sleeve extending past said rearward surface of the workpieces,said first sleeve shank having a weakened section selected to be located generally in line with said rearward surface of the workpieces and to expand radially outwardly at a first predetermined magnitude of relative axial force applied between said outer sleeve and said pin member through said ring portion and said second enlarged sleeve head whereby an enlarged bulbed head is formed in engagement with said rearward surface,said second sleeve shank having a length less than the length of said outer sleeve member, said inner sleeve adapted to move relative to said outer sleeve member as said weakened section expands radially outwardly to form said bulbed head,stop means engageable with said inner sleeve member to stop further axial movement of said inner sleeve relative to said outer sleeve after said bulbed head has been fully formed,said ring portion adapted to shear from said pin shank in response to the application of a second predetermined magnitude of relative axial force greater than said first predetermined magnitude to define a separate ring section whereby said expansion portion is moved through said ring section and into said second bore of said inner sleeve,said expansion portion having a diameter greater than that of said second bore to radially expand said second sleeve shank which in turn radially expands said first sleeve shank into radial engagement with the surfaces of the workpiece bores to provide a predetermined interference fit.