| 摘要 |
1,046,671. Moulding hollow articles; laminating. CHARLES CLAY & SONS Ltd. April 10, 1964, No. 14991/64. Headings B5A and B5N. [Also in Division G2] A multi-layered, hollow, article is formed by heat softening a sheet of thermoplastic material, placing the sheet, with at least one other sheet of thermoplastic material, over a former mounted on an electrically conductive backing member, pressing the sheets over the former by means of a hollow electrically conductive forming tool having a cross-section corresponding to that of the base of the former, so that the sheets are peripherally held between the backing member and the tool, and finally applying a H.F. oscillation between the backing member and the former to bond the sheets together. In the particular embodiment a spectacles case is formed over a former 15, 16 from a heat softened sheet 10, sandwiched between a decorative sheet 19 and a " suede plastic " sheet 18, by means of a forming tool 20, 23, as shown in Fig. 7. The outer wall 23 of the tool is provided with a knife edge so that the sheet is cut simultaneously with the bonding. Prior to the forming operation a strip 14 of woven nylon is placed between members 15 and 16 and welded to the sheets, to form a hinge in the finished case, the forming members 25, 26 being of such a length as not to sever the sheets. A lug 30, formed on the periphery of the case during the above operation is then heated and bent to form a catch to retain the case in its closed position. The heated lug is placed over a projection 45 of platform 31 and bent therearound by a member 37, pivoted to the upper end of spring biased member 39, itself pivoted to base 40. Member 37 is actuated by a piston 38 and at first pivots about the upper end of member 39 until it hits stop 43, whence it moves forward in the direction indicated by arrow 44 thus bending the lug around projection 45 as in Fig. 9. Upon withdrawal of the member 37 the lug springs back to the position in Fig. 10 (not shown) to form the finished catch. The forming may be assisted by resilient material e.g. formed plastics as in Fig. 7. The bonding may be performed by a heat-sensitive adhesive placed between the sheets or may be effected by a direct welding of the sheets. |
