| 摘要 |
<p>592,801. Heating by dielectric loss. RADIO CORPORATION OF AMERICA. Aug. 1, 1944, No. 14676. Convention date, Aug. 23, 1943. [Class 39 (iii)] [Also in Group VIII] Apparatus for bonding dielectric parts, especially layers of thermoplastic material by heating by dielectric loss, comprises a pair of electrodes 31 insulated from one another and forming a unit on a common gradually movable support placed on one side of the layers 35 to be joined and a third electrode 5 placed on the other sides of the layers, and means for setting up a high frequency electric field between the electrodes. The electrodes may comprise conductive rollers, the roller 5 bridging and being wider than the rollers 31 separated by an insulating roller 33. In order to join two layers 35 of great width, the roller 5 extends into an opening in the work table 1, and each of the rollers 31 is connected to a high frequency generator 13 by a transmission line 34 preferably of a length equal to one quarter of the wavelength employed. The rollers 33 are rotated by a motor 17 through gear wheels 21 and belts 25. The roller 5 may be driven at the same peripheral speed by a motor 11, is carried by a yoke 7 pulled upwards by a spring 9 and is preferably earthed. Auxiliary feed rollers may be provided. In a modification, Fig. 4, the lower electrode is a broad elongated conductive strip 5a pressed up by springs 9a in a recess in the work table and is earthed. The upper electrode comprises two rollers 31 or a pair of conductive blocks insulated from each other and mounted as before on the generator 13, which is supported by a bracket 37 with an internally threaded cross piece 39 on a feed screw 47 driven by a reversible motor 49 through bevel wheels 51. The cross piece 39 has at its ends wheels running on tracks 45. The transmission line 34 is surrounded by a casing 53. Specification 573,518 is referred to.</p> |
