| 摘要 |
633,082. Splicing threads. FIRESTONE TIRE & RUBBER CO. Nov. 13, 1946, Nos. 33690 and 33691. Convention dates, June 20. [Class 120 (iii)] Two lengths of organic thermiplastic monofilament are joined to form a continuous filament by overlapping them in parallel relationship and welding them together at the overlapped surfaces by means of a high frequency electrical current. As shown overlapping monofilaments 26, 28 of 25-400 circular mils cross-sectional area are inserted in a slot 41 in a lower electrode assembly 24, resting on the lower electrode 38 which is sandwiched between two glass plates 40 and two insulating blocks 42. The upper electrode 66 having a working edge 73 adapted to enter slot 41. The two electrodes are shaped to abut only along the desired length of weld. Depression of pedal 34 causes the upper electrode assembly to be pressed under the action of spring 91 against the lower assembly so as to press together the monofilaments with a pressure of from about 3 lb. to about 6 1b. per linear inch, and also closes a limit switch 100 to apply by means of a high-frequency generator 36 an e.m.f. to the electrodes having a frequency of 150 to 250 megacycles/sec. for a period of 15-30 secs. after which the circuit is broken by a time switch. The walls of blocks 40 adjacent the filaments may be coated with oil to avoid arcing around the filaments. The excess ends 23, 25 of the filaments may be cropped after welding by chisels which are slidably mounted in the lower assembly 24 and which may be operated manually or automatically by pneumatic or electrical means. In an alternative construction, the working edge of each electrode is flush with the edges of the supporting insulating blocks, and is provided with a longitudinal groove of a depth less than the thickness of a filament, into which one of the filament ends is clipped. The mono-filaments may be of nylon or of a vinylidene chloride base mono-filaments of plastic composition reinforced by fine textile filaments, such resin, or may be solid as "textron." |
