Blind rivet

Abstract

A blind fastener has a sleeve and a pin. The sleeve has a shank with a shank bore and a head with a head bore smaller than the shank bore. The pin has a pin installation portion with a proximal end portion and a distal end portion. The pin also has a breakaway portion with a pin grip, and a pin break groove between the installation portion and the breakaway portion. The pin further has a grip portion at the proximal end portion of the pin installation portion and directly adjacent to the pin break groove. In a pre-installation configuration, the grip portion is in the sleeve bore. In an installation configuration, the grip portion is in the head bore and forms a friction fit with the head bore to prevent the installed sleeve from inadvertently coming free of the installed pin.

1 . A fastener comprising:
 a sleeve having a sleeve bore;   a pin received in the sleeve bore, said pin having a pin installation portion with a proximal end portion and a distal end portion, a pin breakaway portion with a pin grip, and a pin break groove between the installation portion and the breakaway portion; and   a grip portion at the proximal end portion of the pin installation portion and directly adjacent to the pin break groove.   
     
     
         2 . The fastener of  claim 1 , wherein said grip portion has a grip outer diameter and said sleeve bore has a sleeve bore inner diameter, and wherein said grip outer diameter is slightly larger than said sleeve bore inner diameter, so that said grip portion forms a friction fit with said sleeve bore. 
     
     
         3 . The fastener of  claim 1 , said sleeve further having shank portion with a shank bore, and a head portion with a head bore, wherein the sleeve bore comprises the shank bore and the head bore. 
     
     
         4 . The fastener of  claim 3 , said grip portion only received in and forming a friction fit with said head bore in an installation configuration of said fastener. 
     
     
         5 . The fastener of  claim 3 , wherein said shank bore is larger than said head bore. 
     
     
         6 . The fastener of  claim 3 , wherein said grip portion is received in said shank bore in a pre-installation configuration. 
     
     
         7 . The fastener of  claim 1 , said grip portion being knurled. 
     
     
         8 . The fastener of  claim 7 , wherein the knurl comprises channels and raised ridges, whereby the ridges extend substantially parallel to a longitudinal axis of said pin. 
     
     
         9 . The fastener of  claim 1 , wherein said grip portion has a grip diameter and said sleeve bore has a bore diameter, and wherein the grip diameter is larger than the bore diameter to form a friction therebetween. 
     
     
         10 . The fastener of  claim 1 , said sleeve having a distal end portion, wherein said distal end portion of said sleeve forms a tulip in an installation configuration. 
     
     
         11 . A blind rivet comprising:
 a sleeve having a shank with a shank bore, a head with a head bore, a sleeve stop shoulder formed between the shank bore and the head bore, and a distal end, wherein the head bore is smaller than the shank bore;   a pin having a pin installation portion with a proximal end portion and a distal end portion, a pin breakaway portion with a pin grip, and a pin break groove between the installation portion and the breakaway portion;   a crest at the distal end portion of said pin installation portion;   a first smooth section having a distal end portion directly adjacent said crest and a proximal end portion;   a shear ring positioned about said first smooth section and configured to break free of said first smooth section and engage said crest upon a first threshold force;   a first grip portion having a distal end portion directly adjacent the proximal end portion of said first smooth section and a proximal end portion directly adjacent to the pin break groove;   a pin stop shoulder formed between said first smooth portion and said first grip portion, whereby a diameter of said first grip portion is smaller than a diameter of said first smooth portion; and   a second smooth section at a distal end portion of said breakaway portion; and   a second grip portion directly adjacent to said second smooth section and between said second smooth section and said pin grip.   
     
     
         12 . The fastener of  claim 11 , wherein said first grip portion has a first grip outer diameter and said head bore has a head bore inner diameter, and wherein said first grip outer diameter is slightly larger than said head bore inner diameter, so that said first grip portion forms a friction fit with said head bore. 
     
     
         13 . The fastener of  claim 11 , said fastener having a pre-installation configuration in which said first grip portion is received in said shank bore and said second grip portion is received in said head bore. 
     
     
         14 . The fastener of  claim 11 , said fastener having an installation configuration in which said first grip portion is received in said head bore only, said pin stop shoulder engages said sleeve stop shoulder, and said breakaway portion is broken free from said installation portion at said break groove, and said shear ring is engaged with said crest. 
     
     
         15 . A fastener for use with a sleeve, comprising:
 a pin having a pin installation portion with a proximal end portion and a distal end portion, a pin breakaway portion with a pin grip, and a pin break groove between the installation portion and the breakaway portion; and   a grip portion at the proximal end portion of the pin installation portion and directly adjacent to the pin break groove.   
     
     
         16 . The fastener of  claim 15 , wherein said grip portion has a grip outer diameter that is slightly larger than an inner diameter of a sleeve bore of the sleeve, so that said grip portion forms a friction fit with the sleeve bore. 
     
     
         17 . The fastener of  claim 15 , said grip portion being knurled. 
     
     
         18 . The fastener of  claim 17 , wherein the knurl comprises channels and raised ridges, whereby the ridges extend substantially parallel to a longitudinal axis of said pin. 
     
     
         19 . The fastener of  claim 15 , comprising a further grip portion whereby said pin break groove is between said grip portion and said further grip portion.