GB749257A - Improvements in or relating to the manufacture of mandrels for use in blind riveting - Google Patents

Abstract

749,257. Blind riveting; forging mandrels for blind riveting. BRITISH UNITED SHOE MACHINERY CO., Ltd., DIGGLE, H. A., and LOVETT, A. E. May 25, 1954 [Feb. 26, 1953], No. 5342/53. Class 83 (4). In the manufacture of " break-head " or " break-stem " mandrels for blind riveting by the steps of heading a length of wire stock W projecting from a pair of gripping dies 2, 4, releasing the dies, feeding the stock forwardly by one mandrel length and cutting off the mandrel, the necking 48 of the mandrel stem is performed before the mandrel length of wire enters the dies. The necking is performed by tools 32, 34 disposed rearwardly of the dies. The lower die 4 and the lower necking tool 34 are fixed and the upper die and tool 2, 32 respectively are operated in unison by a rocking lever 10, Fig. 5, pivoted at 12 and actuated by a link 14. The lever carries an adjustable stud 8 which engages an extension 2<SP>1</SP> of the upper die 2 and an adjustable stud 36 which engages a part 321 of the upper necking tool 32. By adjusting the stud 36 the depth of the necking 48 may be varied. Hooks 18, 40 withdraw the die and tool during the upstroke of the lever. The heading tool 28 has a recess 30 which forms a conical head on the mandrel. A pair of cutting and pointing tools 26 are provided. The wire is fed by a mechanism of the kind described in Specification 622,705. The position of the necking tools axially of the wire may be varied for changing the position of the neck relative to the head of the finished mandrel. Various forms of neck, Figs. 8-11 (not shown) may be provided by the use of different necking tools. Specifications 555,804, 558,156, [Group VII], 738,741 and 738,760 also are referred to.