GB1377865A - Method and machine for making core rings for tyres - Google Patents

Abstract

1377865 Making pneumatic tyre bead cores ADVANCE MFG CO 19 Oct 1972 [20 Oct 1971 23 Aug 1972] 48200/72 Heading B7C [Also in Division B3] A machine for wrapping continuous lengths of filamentary wire 10 helically around the surface of a core ring 12 comprises devices 100 for gripping and rotating the ring, a supply reel 11 of wire rotatable about its own axis, and apparatus to orbit the reel about an axis which is a tangent to the core ring so as to wrap the wire around the core ring as it is revolved. The core ring 12 is formed of high tensile spring steel wire, and the wire 10 is of steel wire filament, and the finished core is to be embedded in the side wall of a pneumatic tyre, Fig. 3 (not shown). The reel 11 is carried by an orbital wire feed assembly A, Fig. 4, mounted on a plate 13 having an opening 14 to accommodate orbital travel of the reel. A wire guide assembly B controls the placement of the wire on the core ring. As the reel is orbited about the core ring the latter is gripped and revolved about the axis perpendicular to the plane of the ring by a transport assembly C supported on plate 15. A motor (16), Fig. 1 (not shown), drives the assemblies A, B, C via clutch 20 and differential gear 22. A welding tool D is provided for spot welding of the leading and trailing ends of the wire 10. The reel 11 is carried by an orbiting carrier 40 which includes a pivotal housing 41 supporting the axle of the reel and having a pivotal connection 44 perpendicular to the reel axis and parallel to mounting plate 13. A rod 45 guides the wires 10 through its entire orbital path and the carrier 40 is driven through its orbital path by drive shaft 28. A slot 54 is formed in a stationary housing 48, drive sleeve (52), Fig. 5 (not shown), and bearing sleeve (53), Fig. 7 (not shown), so that the core ring may be passed through the parts for location in the centre of the members 48, (52), (53). The wire guide assembly B is synchronized with the orbital movement of assembly A, the drive produced from pulley 29 mounted on shaft 28. A carrier plate 80, Fig. 10, supports a pivotally movable wrapping control assembly 81 which includes a pivotally supported guide tube housing 83. A tube 84 orbits about the axis of a ring gear 77 and generates a conical surface by reason of the oval shape of spring 87. The angle made by the guide tube 84 with the axis of its orbit varies during orbital movement, from 20-35 degrees, but the angle made by the tube 84 with a tangent line to the ring core at the point of wire application remains constant as a result of the tubes' engagement with cam plate 86. The core ring transport assembly C includes an endless roller chain 90 driven by sprocket 91 and synchronized with the assemblies A, B. The chain rollers bear against an arcuate guide rim 95. In a space 96 the core ring is supported by idler rollers 97-99 and gripped by clamp assemblies 100 connected uniformly around the roller chain. Each assembly has a bifurcated mounting bracket 101 attached to a chain link and a fixed jaw 102 with a rubber gripping portion attached thereto. A movable jaw 103 is mounted on a pivotally connected lever 104 which is biased to an open position by a torsion spring 105. A roller 107 on lever 103 formed of low friction plastics material acts against an arcuate plate 110 and ramp 109 supported on a pistonrod 111 of air cylinder 112. The latter provides a resilient support for the plate 110 to maintain a uniform clamping pressure on the core ring while allowing the jaws 102, 103 to open as the wound ring becomes larger in cross-section. Resilient pad assemblies (115), Fig. 19 (not shown), are located midway between the assemblies 100 and are provided for additional core ring support. In operation, both assemblies A, B about their respective axis tangents at the same rate of rotation synchronized with the movement of chain 90 as it rotates the ring core. The pitch of the helices may be controlled by adjusting the orbital speed of assemblies A, B relative to the velocity of the chain 90.