| 摘要 |
1430319 Seaming non-metallic sheet material SUPERFLEXIT 22 June 1973 [23 June 1972] 29797/73 Heading B5K The edges of two flexible heat-sealable sheets 1a, 1b are joined together by arranging the sheets one on the other with their edges aligned and, while the sheets are maintained stationary, heat sealing the edges together by at least one movable press which is moved stepwise around the periphery of the sheets. As shown in Fig. 2, the press is mounted on wheels 5 and comprises an inflatable bag 6 upon which the sheets 1a, 1b are supported and an electrically heated upper platen 7. A rod 8, slidable in a fixed sleeve 9, carries the platen 7 and is hinged at 10 to a control lever 11 pivotable about a point 12. An abutment member comprising one or more blocks 15 is carried by a rod 14 slidable in sleeves 13, 13a so as to be insertable between the platen 7 and a frame component 16 when the platen is in its lowered position. In operation, the edges 3a, 3b of the sheets 1a, 1b are placed on the bag 6 and the platen 7 is lowered by the lever 11 into contact with the edge 3a. The block(s) 15 is/are inserted between the platen 7 and the component 16 and electrical contacts are closed to energize a solenoid so that compressed air passes into the bag 6 and, if the pressure of the compressed air corresponds to a setting given to a manometer, current is supplied to the platen 7 to heat seal the sheets. The platen 7 is heated for a predetermined length of time and its temperature is thermostatically controlled. If the maximum permissible temperature set on the thermostat is exceeded, the current supply to the platen is interrupted and a visual warning device and/or an audible warning device are/is energized. After the platen has been heated for the predetermined period, it is cooled until the temperature reaches a desired value further visible and/or warning device(s) are/is energized and the block(s) 15 is/are removed and the platen 7 is raised. After each heat application period, the sheets are cooled by a jet of cold air directed on to the platen before release of the sheets. The press is moved to the next portion of the edges and the cycle is repeated. An electrical circuit for the operation of the press is described, Fig. 4 (not shown). |
