GB1446777A - Tyre building apparatus - Google Patents

Abstract

1446777 Tyre building apparatus NATIONAL-STANDARD CO Ltd 14 June 1974 [15 June 1973] 28522/73 Heading B7C A tyre building apparatus including a radially expansible and contractible former 4 further includes end assemblies 5, 6 for engaging the tyre beads 152, and for tensioning the tyre components by axial movement of the end assemblies relative to the former when the beads are engaged. The end assemblies are axially movable symmetrically relative to the mid-plane 25 of the former 4 by means of two racks 162, each connected to a respective end assembly, meshing with a pinion 164. The former 4 comprises a plurality of segments 8 of interleaved circumferentially extending members 62, 63. In operation, a preformed carcass (e.g. of radial type) is placed over the former 4, and air is introduced into spaces 126 to pivot the fingers 146 to their bead gripping positions (such positions being determined by adjustable stop collars 166 abutting flanges 116). Air is then introduced into spaces 94 to move tubes 80 and members 84, 132, and 102 connected thereto and the fingers 146 axially outwardly until member 84 of end assembly 6 engages an adjustable stop 171. Thus the carcass is tensioned to a desired extent. The relative axial positions of members 132, 84 are adjustable by means of collars 138. Rotation of shaft 57 causes expansion of the former 4 by means of axially inward movement of nuts 30 and pivoting of segment support arms 17. Simultaneously tubes 90 secured to the nuts 30 are moved axially inwards, and interconnected members 102, 132, 84, tubes 80 and fingers 146 are also moved axially inwards due to expansion of the former. The air pressure in space 94 thus retains the carcass in tension during shaping. In an alternative embodiment (Fig. 8, not shown) turn-up of the carcass ply about each of two axially spaced, bead cores is effected by a respective bladder (172) carried by the fingers 146a) of an end assembly.