GB728951A - Improvements in or relating to the manufacture of rivets - Google Patents

Abstract

728,951. Making rivets. TUCKER EYELET CO., Ltd., G., and HENSHAW, J. N. May 8, 1952 [May 9, 1951], No. 10862/51. Classes 83 (2) and 83 (4). Extruding; forging. -In making rivets, particularly hollow rivets, one end of a wire is upset to form a thickened cylindrical head which is sheared off to form a blank for extruding into a rivet by a stepped plunger. A light alloy wire w, projecting from holding jaws J, is upset by a die 14 to form a head 18, this is then severed by a blade 20 to produce a disc blank and the wire is then fed between the opened jaws J the required distance and again held, this sequence being repeated at a rate of hundreds of times per minute. These blanks are annealed at 380-480‹ C. and placed in the hopper of a second machine having accurately dimensioned dies 36, 24, Fig. 6, and a spring-supported plunger 32 and ejector which forge them at a similar rate to the form E shown. These are annealed and placed in the hopper of a third machine which extrudes each in turn to form a hollow rivet Rl, Fig. 9, at a similar rate. If desired this rivet may have its flange modified in shape by further operations and have its end 70 perforated. Such a rivet may be assembled with a cold-forged steel mandrel in known manner to form a blind-riveting assembly. In a modification the blank 18 is severed by first moving a shearing means in one direction a short distance and then reversing the direction to complete the shear. Any slight variation in the volume of the blank 18 will merely push down the plunger 32 a corresponding amount and vary the volume of the part 49, most of which will be removed when the, rivet is finally perforated. The plungers 14, 36 preferably operate horizontally. Specifications 501,415, 558,156 and 578,363 are referred to.