GB819227A - Improvements in and relating to self-piercing eyelets - Google Patents

Abstract

819,227. Stud and socket fastenings; rivets. UNITED-CARR FASTENER CORPORATION. March 26, 1957 [March 26, 1956], No. 9900/57. CJasses 44 and 89(1) A hollow rivet 10 for piercing through a sheet of material 12 and expanding into engagement with a hollow headed stud 14 to secure the latter to the material, comprises a hollow-shank 24 projecting therefrom, the shank having a radially-enlarged free-end portion 30, with an inwardlyrounded and forwardly-facing outer-surface 32 and an internal support member 34 in recessed-relation thereto and having a centre-portion 37 secured to the free end portion by an upwardly-inclined peripheral wall portion 36, whereby a slug 40 punched out of the sheet material by the enlarged free end portion when the latter is assembled with the stud, will be engaged by the centre portion and carried into the stud so that on the final stage of assembly the slug will be compressed between the centre portion and the head of the stud to effect the expansion of the free end portion of the rivet in the stud. The surface 32 co-operates with an inclined camming surface 42 on the stud which levels to a restricted neck which is of slightly lesser diameter than the diameter of the enlarged end of the rivets so that during attachment the neck of the stud must expand slightly and the enlarged end of the rivet must contract slightly. The internal support member 34 is designed to break away when the rivet is used with material which is too thick for the stud to be accommodated in the cavity.