GB955381A - Apparatus permitting the removal of rivets from tubular members - Google Patents

Abstract

955,381. Separating riveted joints. COMMUNAUTE EUROPEENNE DE L'ENERGIE ATOMIQUE EURATOM. Nov. 30, 1962 [Dec. 9, 1961], No. 45414/62. Heading B3W. An apparatus for removing rivets from a tubular member comprises a punch supported and guided by an operating mechanism which produces displacement of the punch at right angles to the tubular member in the axial direction of the rivet, a two-part mandrel which fits inside the tubular member and an abutment member which is applied externally of the tubular member. In the embodiment described, the apparatus is applied to removing the rivets which secure a reactor fuel element casing to its support. The fuel element casing 1 which is freely suspended from its top end is secured to the support 2 by rivets 3. A rivet-removing punch 4 is mounted in the piston-rod 7c of a compressed air-operated cylinder assembly 7. A feeler rod 15 passes through the piston-rod and punch and has a head 16 which covers ports 7d which pass through the piston 7a. The rivet 3 is hollow and unless the rod 15 engages the hollow centre of the rivet the head 16 is held to the right in Fig. 1 and no pressure is developed on the piston 7a. An abutment 6 is supported from the cylinder 7 by arms 18; and the complete assembly is supported by legs 22 and 23 and guide rollers 10, on a table 9, so that the assembly is free to align itself with the tube. Supported from the underside of the table 9 by legs 31 is a piston and cylinder assembly 26. The piston 26a of this assembly is secured to one part 5a of the two part mandrel. This part 5a comprises a half-open tube which is chamfered at 5h and is closed at the end 5d. There is an opening 5g in the wall of the tube through which the ejected rivet passes. The second part of the mandrel is secured to the table 9 by screws 37 and can be adjusted axially by a wedge 36. Operation.-The suspended fuel element is fitted over the mandrel and compressed air is applied to cylinder 7 through the pipe 33 and also to the cylinder 26 through the pipe 32. When the rod 15 is aligned with the rivet 3 the head 16 seats and covers the ports 7d so that pressure builds up in both cylinders. The piston 26a moves down so that the mandrel is clamped in the tube and the rivet is driven out by the punch 4. The mandrel is unclamped by applying pressure to the pipe 34 or by lowering the apparatus so that a cap 38 butts against an anvil (not shown).