| 摘要 |
<p>727,871. Seaming non-metallic sheet material. SINGER MANUFACTURING CO. Sept. 16, 1953 [Oct. 16, 1952], No. 25625/53. Class 42 (1). Also in Group XI] In a radio-frequency seaming machine is provided a work-supporting bed, through an aperture in which extends a peripheral portion of a driven feed wheel, a lower electrode assembly comprising separate spaced blocks of insulating material secured to said bed on opposite sides of said feed wheel and an electrode spanning the space between and having end portions removably secured to said blocks. As shown, a feed wheel 12 fixed on a shaft 13 is positioned in an aperture in a machine bed 10. The wheel 12 comprises a metallic hub 18, a wheel 19 of insulating material and a rim 20 of rubber bonded thereto. Horizontal shoulder portions 23 and 24 of the bed have secured thereto by screws 25, blocks 26 and 27 of insulating material which support in slots 28 and 29 an electrode 30. The electrode 30 is shaped to straddle the shaft 13 and has material removed therefrom to form apertures 31 and 32 to provide a girder-type structure giving it a substantial positional stability and reduced mutual capacitance with the feed wheel 12. The electrode 30 is also formed with a crown portion 33 which projects above the working surface of the bed 10 to co-operate with a regular reciprocatory upper electrode 34 in applying pressure and a radio-frequency field to the work 46 held between and fed past the electrodes. A spring-pressed roller 37 cooperates with the feed wheel 12 in the usual manner to feed the material with a progressive intermittent motion. Other embodiments show two pairs of electrodes and/or a double feed roller arrangement. Specification 603,412 is referred to.</p> |
