GB1032972A - Process and devices for chevroning pliable sheet material - Google Patents

Abstract

1,032,972. Corrugating. L. V. GEWISS. Oct. 15, 1963 [Oct. 18, 1962], No. 40628/63. Heading B3E. [Also in Divisions B5 and D1] Chevroned structures such as those disclosed in Specifications 815,522 and 815,523, are formed from a sheet of pliable material, e.g. metal foil, paper or plastics material, by placing the sheet material against the ridge lines a<SP>1</SP> or b<SP>1</SP> of a contractible chevroned " motive " structure larger than that to be made, and then contracting the " motive " structure by fluid or mechanical pressure, whilst maintaining the sheet thereagainst. In one embodiment (see Fig. 6), the sheet 3 to be chevroned is sandwiched between two flattened chevroned " moulding " structures 1, 2, which are contained within hermetically sealed sheets 4, 5 inside which a vacuum is maintained, and is then placed between two motive structures 7. The whole is then placed in a bag 8, 9 which is subsequently evacuated to contract the " motive " structures 7 and shape the sheet as shown in Fig. 6. The structures 1, 2 and the sheets 4, 5 may be omitted if necessary. In a further embodiment (see Figs. 11-13, not shown), each of the flattened " moulding " structures 1, 2 are joined along its ridge lines to a " motive " structure, the body thus formed being sealed at its open ends to form an evacuable container. The sheet to be chevroned is sandwiched between sheets 4, 5 and is then placed between the flat surfaces 1, 2 of two of the above evacuable containers, which containers are subsequently evacuated to cause them to contract and to deform the sheet. In yet a further embodiment (see Fig. 15, not shown), each of the evacuable containers described above are reinforced along their ridge lines by metal strips 19a &c., joined at their other ends to a second " motive " structure, so that mechanical as well as fluid pressure may be obtained by placing the modified evacuable containers between the platens of a press with the material to be shaped sandwiched therebetween.