GB920082A - Improvements in apparatus for the manufacture of bead wires for pneumatic tyres - Google Patents

Abstract

920,082. Making tyre bead cores. DUNLOP RUBBER CO. Ltd. July 9, 1959 [July 22, 1958], No. 23432/58. Class 144 (1). A tyre bead core is wound from a single rubberized bead wire 24 by being guided on to the grooved peripheral winding surface 1b of a rotatable former 1, the wire guide 25 being movable axially of the former under the control of a rotatable cam 38 to produce a core of superposed layers of convolutions with the convolutions of each layer seated in the grooves formed between the convolutions in the adjacent layer or layers. As shown, the former surface groove 1b has a cylindrical base with divergent side walls and is designed to wind a core of hexagonal section composed of seven layers respectively of 4, 5, 6, 7, 6, 5, 4 convolutions. The former 1 is mounted on a rotatable driven shaft 2, and the wire guide, comprising a grooved pulley 25, is mounted on a pivoted lever 26 to overlie the former groove 1b The pulley 25 is biased towards the winding groove by feeding the wire over a pulley 31 mounted on an extension of the lever 26. The lever 26 is pivoted to a slide 29 movable axially of the former in a housing 30 and coupled, by means of a slotted block 33, with one end of a lever 34, the lever 34 being pivoted intermediate its ends to the machine frame 5 and having its other end 36 formed as a cam follower engaged in a cam groove 37 of a cylindrical cam 38. The cam 38 is rotatably mounted coaxially with the shaft 2 on a flame extension 39 and has a 37-tooth driving sprocket 40 which is operable in one-tooth steps, defining the axial positions of successive convolutions, by a pawl 42 carried by a pivoted arm 44. The arm 44 is connected by a link 47 to one end of a centrally pivoted lever 49 the other end of which carries a cam follower 51 which is engageable in an inverted V-shaped cam groove 52 in a block 53 carried by the former 1 in a predetermined angular position corresponding to the end of one complete revolution of the former during winding. The lever 49 is also linked to a stop pawl 65 so that, when the cam groove 52 engages the follower 51 at the end of each revolution of the former to effect movement of the link 47, and thereby rotation of sprocket 40 and cam 38, the pawl 65 is engaged with the sprocket 40 to limit the rotation to a step of one tooth. Subsequently the cam groove 52 moves the lever 49 to disengage pawl 65 and to reset the pawl 42. Reverse rotation of the sprocket is prevented by a flat spring 66. To permit removal of the wound bead core, the former comprises two fixed diametrically-opposed peripheral segments 11, 12 mounted on a backplate 15, and two intervening segments 13, 14, each pivoted at one end 16, 17 to the backplate and collapsible radially inwardly about their pivots by a rotatable arm 22 having its ends engaged in slots 18, 19 in the segments. In an alternative construction, instead of a cylindrical control cam a plate cam is used rotating in, or parallel to, the plane of movement of the guide slide.