GB586527A - Improvements in rivets and methods of riveting - Google Patents

Abstract

586,527. Setting tubular rivets. STEVENS, A. H. (Huxon Holding Corporation). July 18, 1944, No. 13741. [Class 43] [Also in Group XXV] Relates to tubular rivets, for use in riveting when access is to be had to one side only of the work, and of the type in which closure is effected by tension applied to a central pin, and consists in a modified arrangement of the contacting surfaces of the pin and rivet, and in the shape of the preformed head. Cylindrical parts 37, 33, Fig. 1, of the pin and rivet are initially a light press fit to maintain the parts in assembled relation prior to and during introduction into the dimple 15. The projecting end of the rivet is progressively work-hardened towards the end as indicated diagrammatically by the shading 26 to increase the resistance of this part of the rivet to collapse. The part 37 of the pin leads by a tapered shoulder 38 to a short cylindrical part 39 of less diameter followed by a groove 41 that is complementary to a groove 28-formed in the rivet. A deeper groove 43 determines the point at which the pin breaks and the remainder of the pin is grooved at 45 for engagement by the jaws 50 of the riveting machine. The rivet head has a projecting flange 29 connected to the head by a narrow neck adjacent the groove 28. During setting, the abutment 54 of the machine presses against the head of the rivet whilst the member 52 applies tension to the rivet. In the first stage the head of the pin causes the rivet to bulge forming a second head 55, Fig. 3, the location of the bulge being determined by the work hardened portion. Engagement of the shoulder 38 on the pin with a corresponding shoulder on the rivet ends this stage and, the pull on the pin rising, a member 59 comes into action causing its reduced end 60 to bear on the flange 29 shearing it at its connecting neck and driving it into the annular space between the grooves 41, 28 when it is upset to fill the space the setting operation being completed by fracture of the pin. In a modification for use with thicker sheets one of which is countersunk to receive the preformed head a short cylindrical section on the pin beyond the breaking groove serves to expand the tubular shank of the rivet completely to fill the hole in the sheets prior to the formation of the second head. A similar rivet is described with an ordinary head for use with sheets that are not countersunk. In some cases to avoid the further increase in the pull on the pin to cause fracture, the pressure on the machine may be relieved and the pin broken by angling the machine laterally. Specifications 424,241, 426,635, 550,898, [Group XXII], 554,194 and 554,267, [Group XXII], are referred to.