Rivets

Abstract

A rivet for fastening workpiece members, the rivet including a body comprising a shank extending in a first, longitudinal direction and a head extending in a second, substantially transversal direction, a bore being defined through the shank and the head of the body; and, a stem comprising a main longitudinal portion arranged for insertion into said bore, and an enlarged portion arranged for radially expanding the shank when the enlarged portion is forced into said bore to fasten the workpiece members; the rivet being configured for insertion into respective apertures formed in the workpiece members; and the rivet being further configured such that when the workpiece members are fastened, the head of the body of the rivet is displaced relative to the shank to engage with the stem to lock the stem in place relative to the body and/or the workpiece members.

1 . A rivet for fastening workpiece members, the rivet comprising:
 a body comprising a shank extending in a first, longitudinal direction and a head extending in a second, substantially transversal direction, a bore being defined through the shank and the head; and,   a stem comprising a main longitudinal portion arranged for insertion into said bore, and an enlarged portion arranged for radially expanding the shank when the enlarged portion is forced into said bore to fasten the workpiece members;
 the rivet being configured for insertion into respective apertures formed in the workpiece members; and 
 the rivet being further configured such that when the workpiece members are fastened, the head of the body of the rivet undergoes displacement relative to the shank to engage with the stem to lock the stem in place relative to the body and/or the workpiece members. 
   
     
     
         2 . A rivet according to  claim 1 , wherein the main longitudinal portion of the stem comprises at least one stem locking feature to facilitate the engaging of the head of the body of the rivet with the stem. 
     
     
         3 . A rivet according to  claim 2 , wherein the at least one stem locking feature comprises a stem shoulder and/or a stem groove. 
     
     
         4 . A rivet according to  claim 1 , wherein the head of the body of the rivet comprises at least one body locking feature to facilitate the engaging of the head of the body of the rivet with the stem. 
     
     
         5 . A rivet according to  claim 4 , wherein the at least one body locking feature comprises an inner body shoulder and/or an inner body groove. 
     
     
         6 . A rivet according to  claim 1 , wherein said head has an outer curved or domed profile. 
     
     
         7 . A rivet according to  claim 6 , wherein said head has a flat or curved underhead contact surface for abutment against a corresponding respectively flat or curved surface of one of the workpiece members. 
     
     
         8 . A rivet according to  claim 1 , wherein said displacement comprises pivoting of at least a portion of the head around a region of the head constrained between a surface of one of the workpiece members and an outer rim of a tool for setting the rivet. 
     
     
         9 . A rivet according to  claim 1 , wherein at least a substantial portion of the head undergoes yielding to enable said displacement to lock the stem in place relative to the body and/or the workpiece members. 
     
     
         10 . A rivet according to  claim 1 , wherein the body is formed as a single piece and/or is made of steel. 
     
     
         11 . A rivet according to  claim 10 , wherein the steel is in an annealed condition. 
     
     
         12 . A rivet according to  claim 1 , wherein the stem is formed as a single piece and/or is made from steel. 
     
     
         13 . A rivet according to  claim 12 , wherein the steel is in a hardened condition. 
     
     
         14 . A rivet according to  claim 1 , wherein the body shank has a plain cylindrical outer profile, or is splined. 
     
     
         15 . A rivet according to  claim 14 , wherein the body shank includes a voided section. 
     
     
         16 . A rivet according to  claim 1 , wherein the enlarged portion of the stem comprises a tapered section arranged to facilitate the radial expansion of at least part of the body shank. 
     
     
         17 . A workpiece comprising a rivet according to  claim 1 , wherein said workpiece further includes a curved surface for abutment with the head of the body of the rivet. 
     
     
         18 . A method of fastening workpiece members using a rivet comprising a body having a shank extending in a first, longitudinal direction and a head extending in a second, substantially transversal direction, a bore being defined through the shank and the head of the body, and a stem having a main longitudinal portion arranged for insertion into said bore, and an enlarged portion arranged for radially expanding the shank, the method comprising:
 inserting the rivet into respective apertures formed in the workpiece members;   forcing the enlarged portion into said bore to fasten the workpiece members; and,   displacing the head of the body of the rivet relative to the shank to engage with the stem to lock the stem in place relative to the body and/or the workpiece members.   
     
     
         19 . A method according to  claim 18 , wherein the step of displacing the head of the body relative to the shank to engage with the stem to lock the stem in place relative to the body and/or the workpiece member is performed immediately subsequently to the step of forcing the enlarged portion into the bore to fasten the workpiece members. 
     
     
         20 . A method according to  claim 19 , wherein the step of displacing the head of the body relative to the shank to engage with the stem to lock the stem in place relative to the body and/or the workpiece member is performed immediately subsequently to, and as a result of a continuation of a same action responsible for, the step of forcing the enlarged portion into the bore to fasten the workpiece members.