METHOD AND APPARATUS FOR PRODUCING A CONTINUOUS BAND OF RUBBERIZED FABRIC PROVIDED WITH TRANSVERSAL FORCING ELEMENTS

摘要

1468428 Seaming non-metallic sheet material INDUSTRIE PIRELLI SpA 24 June 1974 [3 July 1973] 27882/74 Heading B5K Apparatus for manufacturing a continuous band by butt splicing, without overlapping, rectangular pieces 2, 5 of rubberized fabric comprises (a) a splicing device 4 having two operating parts 30, 31, Figs. 3 and 4, each having a series of fingers 48, 52 and 49, 53, respectively, on a base element 32, 33 and on a movable ledger 34, 35 adapted to grip the pieces 2, 5, the fingers having serrated gripping surface portions 4811, 4911, 5211, 5311 located, in operation at a predetermined distance from the ends E, V to be butt spliced, (b) a transporting device 3 to arrange the pieces 2, 5 at the device 4, and (c) a drum 6 for collecting the continuous band formed by the splicing of the pieces 2, 5. A sheet of rubberized fabric provided with longitudinal reinforcing metal cords is cut into rectangular pieces which are spliced together to form a band with the metal cords extending transversely thereof. Each cut piece 2 is supplied by a roller bed 1, Fig. 2, to abut a vertical plate 8 adjustable by a hand wheel 9. The device 3, Fig. 6, comprises a metal plate 11 suspended by a support 12 and a piston 13 from a carriage 14 slidable on a beam 16 which carries a cylinder 19 of a double-acting piston 20 secured to the carriage 14. The plate 11 is provided with electromagnets 21 to engage the piece 2 during its positioning on the device 4. The device 4 comprises four columns 23 connected by two parallel shafts 24, Fig. 4, on which are keyed pistons 25 of double-acting cylinders 26. The stroke of each cylinder 26 is adjustable by a ring nut 27 screwed on to the control part of each shaft 24. Each cylinder 26 is fast with a first hollow shaft 28 on the corresponding shaft 24. A second hollow shaft 29 is fixed to the shaft 24. Each pair of shafts 28, 29 is connected to one part 30 or 31, respectively. Each part 30, 31 comprises a base element 32, 33, Fig. 3, fast with the shaft 28, 29 by a pair of vertical hollow shafts 36, 37, and a movable upper ledger 34, 35 joined to vertical shafts 38, 39 slidable vertically in the shafts 36, 37. The shafts 38, 39 are connected to rods 40, 41 actuated by double-acting cylinders 44, 45, with the interposition of gears 46, 47, to move vertically the ledges 34, 35. The elements 32, 33 comprise a first series of coplanar interdigitated fingers 48, 49, Figs. 3 and 7, and a second series of coplanar fingers 50, 51. The ledgers 34, 35 have a first and second series of fingers 52 and 53, 54 and 55 secured thereto through inflation chambers 56, 57, Fig. 3. The fingers 48, 49, 52, 53 each have a smooth surface 481, 491, 521, 531 adjacent the ends E, V to be spliced and a serrated gripping surface portion 4811, 4911, 5211, 5311 spaced therefrom. The gripping surfaces are spaced apart by a distance B less than the distance A by which the smooth surfaces are spaced apart. In operation, the piece 5 is located with its trailing end U at the part 31 with the ledgers 34, 35 raised and the cut piece 2 travels on the bed 1 until an end S thereof contacts the plate 8 so as to be aligned with an edge L of the piece 5. The plate 11 is brought into contact with the piece 2 and current is supplied to the electromagnets 21. The piston 13 lifts the plate 11 and the cylinder 19 moves the carriage 14 until the leading end E of the piece 2 is aligned with the part 30. The current supply to the electromagnets 21 is disconnected and the device 3 returns to its initial position. The ledgers 34, 35 are lowered and the chambers 56, 57 are inflated to bring the gripping surfaces of the upper fingers into contact with the pieces 2, 5. The cylinders 26 are actuated so that the part 30 moves towards the part 31 which remains stationary and the ends E, U are butt spliced with the rubber of the fabric filling the space between the smooth surfaces of the fingers. The part 30 is retracted and, as the rubber is in plastic condition, it returns to the thickness that it had before splicing at the smooth surfaces of the fingers. The chambers 56, 57 are deflated and the ledgers 34, 35 are lifted and the band is wound on the drum 6 to leave the trailing end of the piece 2 beneath the part 31 for the next splice. In a modification (not shown), butt splicing is facilitated by providing lamps for heating by radiation the leading end of the piece 2 to the softening temperature of the rubber before it is picked up by the device 3.