| 摘要 |
931,806. Dielectric heating apparatus. L. PUNGS, and K. LAMBERTS. Aug. 25, 1959 [Sept. 2, 1958], No. 29015/59. Class 39 (3). [Also in Group XL (c)] Energy at frequencies between 60 x 10<SP>6</SP> and 10<SP>9</SP> c.p.s. is supplied to a dielectric heating system by a coaxial line, and the workpiece, e.g. two sheets of thermoplastic material to be seamwelded together, is progressively moved through a gap in the inner conductor and through a slot in the outer conductor. In one arrangement, Fig. 1, the workpiece is passed between plates 8 forming flanges of a slot 6, 7 in the outer conductor 1 and through a heating gap, represented as a condenser 4, 5, in the inner conductor 2. The line is fed by a high-frequency generator 3 and tuned by a disc 9. The welding electrodes may form parts of the inner conductor of the coaxial line and may be designed as spot-welding electrodes capable of being moved up and down or as roller electrodes (Figs. 2 and 3, not shown). In modified forms of the arrangement shown in Fig. 1 a coaxial line is spaced at its end from the earthed surface of a work table, and tuning is effected by a slide surrounding either the outer conductor or the inner conductor of the line (Figs. 4 and 5, not shown). An arrangement for the simultaneous production of two welds is also described (Fig. 8, not shown) in which the working condenser is divided into two parts by a conductive surface which may form the work-table. |
