Patent GB-754765-A (GB)
Title: Improvements in or relating to metal sheathed insulating blanket and method and apparatus for its manufacture
IPC: B21D13/02
Filed: 1954-05-10
Abstract: 754,765. Making composite sheets. JOHNSMANVILLE CORPORATION. May 10, 1954 [Nov. 12, 1953], No. 13538/54. Addition to 669,846. Classes 83 (2) and 83 (4). [Also in Group XIII] Stamping.-An improvement or modification of the method of forming a segment of a sheet metal sealing envelope for a flexible heat insulating blanket as disclosed in the parent Specification comprises forming aligned corrugations in a strip of sheet metal having first and second walls extending angularly from each other wherein a first corrugation is formed in said first wall transversely to the line of junction with the second wall by first male and female dies and a second corrugation is formed in the second wall in alignment with the first corrugation by second male and female dies one of which co-operates at least in part with the first male die as part of the first female die in forming the first corrugation. The blanket comprises a flexible thermal insulating filler material 2 enclosed by a corrugated sheet metal channel section 6 and a metal cover sheet 22 spot-welded together. The ends of the walls 16 and the lands 15 of the corrugations 12 (Fig. 3), terminate flush with the side walls 8 of the channel section as at 171 and the ends of the side wall corrugations are joined to the ends of the corrugations 12 by a saddle portion 17. The lands of the side wall corrugations are flattened as at 18 prior to forming the edge flange portion 20. Apparatus for carrying out the method comprises a conventional press provided with a grooved platen 28 and a male die member 36 carried by a beam 40 operated by air cylinders 46. Mounted in the groove 30 of the platen 28 is a composite female die structure comprising spaced side dies 52 and intermediate spacer blocks 54 (Fig. 15). Each side die 52 comprises first and second blocks 58 and 60 respectively secured to side tie bars 62 and a bottom tie bar 72 adjustably, secured in the platen groove. The top of the first block 58 has a groove 78 for receiving bars 80 between which the male die 36 lies on its closed position. A rubber block 86 is accommodated in a widened portion of the groove between the bars 80 and a face plate 88 is attached to the block 58 with its outer surface flush with the end surface of the rubber block. The plate has a groove 90 for receiving the male die 36. The first block has a central slot 94 which terminates in a bore 96 for receiving an. hydraulic piston 98 slotted to receive the rear edge of a male side die plate 102. Slidably mounted between blocks 58 and 60 is a third block 112 comprising a body 113 and a face plate 114 made up of knurled sections 115 spaced apart to provide a vertical slot 119. The body 113 also has a vertical slot 120 the upper part of which receives the male die 36. An element 122 having a flanged head 130 has a concave forward edge 126 and forms a bottom for the female side die slot portion 119. Mounted in the slots 119, 120 is a smasher plate 132 affixed to a rod 134 extending through the body 113 of block 112 and into the bore 136 of a hydraulic piston 138 mounted in the second block 60 which also has a groove in its upper surface for receiving the male die 36. The third block 112 is held in open die position by springs 150 and 148, the spring 148 reacting between the die plate 102 and the smasher plate 132 and the spring 150 reacting between the piston 138 and the block 112. In operation, a channelshaped metal strip is placed over the composite female die structure with its side walls between face plates 88 and 114 of blocks 58 and 112 respectively. The die member 36 is lowered to closed position which forms a corrugation in the base of the channel section and extrudes the rubber blocks 86 to form a portion of the corrugations on the side walls (Fig. 8). To provide a female side die to co-operate with the extruded rubber, pressure fluid is supplied to piston 138 to move the block 112 towards the block 58 against spring 148 so that the concave edge of member 122 forms a shaped bottom for the upper portion of the side die groove. Pressure fluid is now supplied to the piston 98 to move the male die plate 102 to the closed position to complete the side corrugation as shown in Fig. 9a. High-pressure fluid is then applied to the piston 138 with the result that the knurled plate 114 clamps the side wall against the face plate 88 and when the spring 150 is compressed the rod 134 bottoms in the piston bore. Further travel of the piston moves the smasher plate 132 forward to flatten a portion of the corrugation against the side die plate 102 and face plate 88 as in Figs. 10, 10a. After the flattening step the fluid pressure is removed and springs 148 and 150 return the members to their initial positions. By rearrangement of the side dies as shown in Fig. 11, the corrugations in the side walls may be formed outwardly as shown in Fig. 11b.