| 摘要 |
790,883. Rubber-coating tyre bead cores by extrusion. NATIONAL-STANDARD CO. Feb. 16, 1956 [March 3, 1955], No. 4855/56. Class 87(2). [Also in Group XXXIV] Two or more tyre bead rings are formed simultaneously by feeding at least two bead wire tapes 1, 2 in spaced side-by-side relation through means, such as an extruder 20, which coats the tapes with rubber to form a single ribbon having twice the width x of rubber between the tapes as there is between the wires of each tape, the ribbon being subsequently wound spirally to form a ring, Fig. 4, which is separable medially of the spacing between the tapes into separate bead rings. As shown, the tapes 1, 2 each comprise four parallel wires 4 held together by a light filling or weft wire 5 and are drawn from spools 12 through a preheater 17 to a screw-acting tubing machine 18 where it passes through a die head 20 to be rubbercoated. The die head comprises two sections 21, 22 clamped together by a U-clamp 24 and having parallel slots therein, Fig. 11, on each side of the die chamber 26 to receive baffle plates 28, 28a and 30, 30a. The baffles 28, 28a, Fig. 13, are on the entry side of the die chamber and define side by side slots 32 spaced by a web 33 to position the tapes 1, 2. The baffles 30, 30a on the outlet side of the die chamber define slots 34 spaced by a web 35 which does not, however, prevent flow and adherence of the rubbercoating at the adjacent edges of the tapes on emergence from the baffles 30, 30a. Where weftless tape is used, the wires being drawn from a fan-wise arrangement of spools 12, the inlet baffles define spaced sets of spaced apertures 39, Fig. 14, for the separate wires. The adhering rubber-coated tapes form a single ribbon which is passed through a cooler 44 to a festooning unit 46 and thence between a guide roll 50 and a pinch roll 68 which has a rib 69, Fig. 8, to cleave into the rubber between the tapes. The rib 69 on the roll 68 is fed with a tack reducing agent, such as paraffin, from a reservoir 70. The ribbon is then guided round a roll 80 and over a bend-producing roller 82 to a feeding unit 88 and thence to a bead winding drum 90. The end of the ribbon is held to the drum by a clamp 89 and the ribbon is pressed against the drum surface, by a spring-loaded roller 98 which also has a ribbed periphery to indent each convolution of the wound ribbon along the line previously impressed by the roll 68. The ribbon is severed on completion of the winding by a knife 92, and the composite ring is ejected from the drum by ejector fingers 95, the drum surface being relieved by grooves 105 to prevent any tendency for the ring to bind thereon due to its width. U.S.A. Specifications 2,151,306 and 2,190,805 are referred to. |
